1
|
Pagès-Vilà N, Gamba I, Clémancey M, Latour JM, Company A, Costas M. Proton-triggered chemoselective halogenation of aliphatic C-H bonds with nonheme Fe IV-oxo complexes. J Inorg Biochem 2024; 259:112643. [PMID: 38924872 DOI: 10.1016/j.jinorgbio.2024.112643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 05/30/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024]
Abstract
Halogenation of aliphatic C-H bonds is a chemical transformation performed in nature by mononuclear nonheme iron dependent halogenases. The mechanism involves the formation of an iron(IV)-oxo-chloride species that abstracts the hydrogen atom from the reactive C-H bond to form a carbon-centered radical that selectively reacts with the bound chloride ligand, a process commonly referred to as halide rebound. The factors that determine the halide rebound, as opposed to the reaction with the incipient hydroxide ligand, are not clearly understood and examples of well-defined iron(IV)-oxo-halide compounds competent in C-H halogenation are scarce. In this work we have studied the reactivity of three well-defined iron(IV)-oxo complexes containing variants of the tetradentate 1-(2-pyridylmethyl)-1,4,7-triazacyclononane ligand (Pytacn). Interestingly, these compounds exhibit a change in their chemoselectivity towards the functionalization of C-H bonds under certain conditions: their reaction towards C-H bonds in the presence of a halide anionleads to exclusive oxygenation, while the addition of a superacid results in halogenation. Almost quantitative halogenation of ethylbenzene is observed when using the two systems with more sterically congested ligands and even the chlorination of strong C-H bonds such as those of cyclohexane is performed when a methyl group is present in the sixth position of the pyridine ring of the ligand. Mechanistic studies suggest that both reactions, oxygenation and halogenation, proceed through a common rate determining hydrogen atom transfer step and the presence of the acid dictates the fate of the resulting alkyl radical towards preferential halogenation over oxygenation.
Collapse
Affiliation(s)
- Neus Pagès-Vilà
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain
| | - Ilaria Gamba
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain; Departamento de Química, Facultad de Ciencias, Universidad de La Laguna, Av. Astrofísico Sánchez s/n, 38200 La Laguna, Spain.
| | - Martin Clémancey
- Univ. Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire de Chimie et Biologie des Métaux, F-38000 Grenoble, France
| | - Jean-Marc Latour
- Univ. Grenoble Alpes, CNRS, CEA, IRIG, Laboratoire de Chimie et Biologie des Métaux, F-38000 Grenoble, France
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain.
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/ Maria Aurèlia Capmany 69, 17003 Girona, Catalonia, Spain.
| |
Collapse
|
2
|
Juvanteny A, Souilah C, Quintero R, García-Bellido C, Pagès-Vilà N, Corona T, Salvador P, Company A. Unraveling the Mechanism of Hydrogen Atom Transfer by a Nickel-Hypochlorite Species and the Influence of Electronic Effects. Inorg Chem 2024. [PMID: 39042784 DOI: 10.1021/acs.inorgchem.4c00360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2024]
Abstract
The oxidation of hydrocarbons is an important chemical transformation with relevance to biology and industry. Ni-catalyzed transformations are more scarce compared to Mn or Fe but have gained attention in recent years, affording efficient oxidations. Understanding the mechanism of action of these catalysts, including the detection and characterization of the active nickel-oxygen species, is of interest to design better catalysts. In this work, we undertake a theoretical study to unravel the mechanism of formation of the previously reported [Ni(OCl)(HL)]+ (H2) and how it activates C-H bonds. We disclose that the active species is indeed compound [Ni(O)(HL)]+, formed after homolytic cleavage of the O-Cl bond in H2 assisted by a chlorine radical. [Ni(O)(HL)]+ mediates C-H activation through an asynchronous concerted mechanism, in which the transition state is given by hydrogen atom transfer. Moreover, the electronic tuning of the ligand has a very modest impact on the stability and reactivity of the corresponding X2 species. Effective oxidation state analysis reveals an intriguing electronic structure of H2 and [Ni(O)(HL)]+, in which both the macrocycic HL ligand and the OCl and O ligands behave as redox noninnocent. Such redox activity leads to a fully ambiguous oxidation state assignation.
Collapse
Affiliation(s)
- Adrià Juvanteny
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, Girona 17003, Spain
| | - Charafa Souilah
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, Girona 17003, Spain
- Fachbereich Chemie, Philipps-Universitat Marburg, Hans-Meerwein-Str. 4, Marburg DE 35032, Germany
| | - Raquel Quintero
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, Girona 17003, Spain
| | - Carlos García-Bellido
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, Girona 17003, Spain
- Departamento de Química Inorgánica, CSIC and Universidad de Sevilla, Instituto de Investigaciones Químicas (IIQ), Sevilla 41092, Spain
| | - Neus Pagès-Vilà
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, Girona 17003, Spain
| | - Teresa Corona
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, Girona 17003, Spain
| | - Pedro Salvador
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, Girona 17003, Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Maria Aurèlia Capmany 69, Girona 17003, Spain
| |
Collapse
|
3
|
Robb MG, Chong SV, Brooker S. Iron(II) spin crossover complexes of tetradentate Schiff-bases: tuning T1/2 by choice of formyl-heterocycle component. Dalton Trans 2024; 53:10974-10981. [PMID: 38873979 DOI: 10.1039/d4dt00884g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2024]
Abstract
Four new tetradentate Schiff-base ligands were prepared in situ from the 1 : 2 condensation of 1,3-diaminopropane and either 2-thiazolecarboxaldehyde (L2thiazole), 4-thiazolecarboxaldehyde (L4thiazole), 4-oxazolecarboxaldehyde (L4oxazole), or 5-bromopyridine-2-aldehyde (L5Br-pyridine), and complexed with [Fe(NCS)2(pyridine)4] to give four monometallic FeII complexes, [Fe(Lheterocycle)(NCS)2]. Structural characterisation shows the expected octahedral FeII centres in all cases, with Lheterocycle occupying the equatorial plane and the two thiocyanate ligands trans to each other, resulting in an N6 coordination sphere. Solid state magnetic measurements showed that the two complexes with the thiazole-based ligands exhibit the beginning of a spin transition above 300 K, with T1/2 = 350 K for [Fe(L4thiazole)(NCS)2] and 400 K for [Fe(L2thiazole)(NCS)2], whereas the 4-oxazole-based ligand gives [Fe(L4oxazole)(NCS)2] which remains high spin at all measured temperatures (50-400 K). Interestingly, [Fe(L5Br-pyridine)(NCS)2] crystallised as two solvent-free polymorphs: magnetic measurements on samples with both polymorphs present showed a two step SCO with an abrupt transition at T1/2 = 245 K assigned to the transition in polymorph A (as this was also seen in a sample of pure polymorph A), and a gradual transition at T1/2 = 304 K assigned to polymorph B. These findings show that the order of increasing ligand field strength for these heterocycles is 4-oxazole ≪ 5Br-pyridine < 4-thiazole < 2-thiazole.
Collapse
Affiliation(s)
- Matthew G Robb
- Department of Chemistry and MacDiarmid Institute of Advanced Materials and Nanotechnology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
| | - Shen V Chong
- Robinson Research Institute, School of Engineering, Victoria University of Wellington, PO Box 33436, Lower Hutt 5046, New Zealand
| | - Sally Brooker
- Department of Chemistry and MacDiarmid Institute of Advanced Materials and Nanotechnology, University of Otago, P.O. Box 56, Dunedin 9054, New Zealand.
| |
Collapse
|
4
|
Regueiro A, García-López V, Forment-Aliaga A, Clemente-León M. Chiral spin-crossover complexes based on an enantiopure Schiff base ligand with three chiral carbon centers. Dalton Trans 2024; 53:10637-10643. [PMID: 38860297 PMCID: PMC11197010 DOI: 10.1039/d4dt00924j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Accepted: 06/01/2024] [Indexed: 06/12/2024]
Abstract
The preparation of Fe(II) complexes combining monodentate NCX- (X = S or Se) and the tetradentate Schiff base chiral ligands RR-L1 and SS-L1 = (RR- or SS-L1 = 1R,2R or 1S,2S)-N1,N2-bis(pyridin-2-ylmethylen)cyclohexane-1,2-diamine in acetone results in an unexpected reaction. Thus, four enantiomerically pure compounds of formulas [Fe(RR-S-L2)(NCX)2] and [Fe(SS-R-L2)(NCX)2] (X = S or Se) are formed by the new asymmetrical ligand L2. In L2, one acetone solvent molecule is incorporated into the ligand forming a bond with the C atom of one of the two CN imine groups of L1, which is transformed into an amine (Mannich reaction). This reaction is diastereoselective as the incorporation of acetone leads to an asymmetric C adjacent to the NH group with opposite chirality S- or R- to that of the cyclohexane carbons (RR- or SS-, respectively). Therefore, L2 contains three C chiral centers. Structural and magnetic characterization of these compounds demonstrates that they show in the bulk a gradual spin-crossover behavior and LIESST effect. Interestingly, the presence of an intramolecular hydrogen bond between the integrated acetone molecule and the NH group can trigger a secondary stimuli-responsive behavior in the system. Therefore, by changing the solvent polarity, the color of the complex in solution can be easily tuned.
Collapse
Affiliation(s)
- Alejandro Regueiro
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático José Beltrán 2, 46980 Paterna, Spain.
| | - Víctor García-López
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático José Beltrán 2, 46980 Paterna, Spain.
| | - Alicia Forment-Aliaga
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático José Beltrán 2, 46980 Paterna, Spain.
| | - Miguel Clemente-León
- Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, Catedrático José Beltrán 2, 46980 Paterna, Spain.
| |
Collapse
|
5
|
Ji T, Su S, Wu S, Hori Y, Shigeta Y, Huang Y, Zheng W, Xu W, Zhang X, Kiyanagi R, Munakata K, Ohhara T, Nakanishi T, Sato O. Development of an Fe II Complex Exhibiting Intermolecular Proton Shifting Coupled Spin Transition. Angew Chem Int Ed Engl 2024; 63:e202404843. [PMID: 38622084 DOI: 10.1002/anie.202404843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2024] [Revised: 04/13/2024] [Accepted: 04/15/2024] [Indexed: 04/17/2024]
Abstract
In this study, we investigated reversible intermolecular proton shifting (IPS) coupled with spin transition (ST) in a novel FeII complex. The host FeII complex and the guest carboxylic acid anion were connected by intermolecular hydrogen bonds (IHBs). We extended the intramolecular proton transfer coupled ST phenomenon to the intermolecular system. The dynamic phenomenon was confirmed by variable-temperature single-crystal X-ray diffraction, neutron crystallography, and infrared spectroscopy. The mechanism of IPS was further validated using density functional theory calculations. The discovery of IPS-coupled ST in crystalline molecular materials provides good insights into fundamental processes and promotes the design of novel multifunctional materials with tunable properties for various applications, such as optoelectronics, information storage, and molecular devices.
Collapse
Affiliation(s)
- Tianchi Ji
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Shengqun Su
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Shuqi Wu
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Yuta Hori
- Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Yasuteru Shigeta
- Center for Computational Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki, 305-8577, Japan
| | - Yubo Huang
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Wenwei Zheng
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Wenhuang Xu
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Xiaopeng Zhang
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| | - Ryoji Kiyanagi
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki, 319-1195, Japan
| | - Koji Munakata
- Neutron Science and Technology Center, Comprehensive Research Organization for Science and Society, 162-1 Shirakata, Tokai, Ibaraki, 319-1106, Japan
| | - Takashi Ohhara
- J-PARC Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki, 319-1195, Japan
| | - Takumi Nakanishi
- Institute for Materials Research, Tohoku University, 211 Katahira, Aoba Ward, Sendai, Miyagi, 980-8577, Japan
| | - Osamu Sato
- Institute for Materials Chemistry and Engineering & IRCCS, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka, 819-0395, Japan
| |
Collapse
|
6
|
Cramer HH, Duchemin C, Kovel CB, Kim J, Pecoraro MV, Chirik PJ. Ligand Field Sensitive Spin Acceleration in the Iron-Catalyzed [2 + 2] Cycloaddition of Unactivated Alkenes and Dienes. J Am Chem Soc 2024; 146:9947-9956. [PMID: 38537152 DOI: 10.1021/jacs.4c00591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/11/2024]
Abstract
Redox-active pyridine(diimine) (PDI) iron catalysts promote the reversible [2 + 2] cycloaddition of alkenes and dienes to cyclobutane derivatives that have applications ranging from fuels to chemically recyclable polymers. Metallacycles were identified as key intermediates, and spin crossover from the singlet to the triplet surface was calculated to facilitate the reductive coupling step responsible for the formation of the four-membered ring. In this work, a series of sterically and electronically differentiated PDI ligands was studied for the [2 + 2] cycloaddition of ethylene and butadiene to vinylcyclobutane. Kinetic studies revealed that the fastest and slowest turnover were observed with equally electron-deficient supporting ligands that either feature phenyl-substituted imine carbon atoms (MeBPDI) or a pyrazine core (MePZDI). While the oxidative cyclization was comparatively slow for both catalysts, the rate of reductive coupling─determined by stoichiometric 13C2H4 labeling studies─correlated with the turnover frequencies. Two-state density functional theory studies and the distinct electronic structures of related (iPrBPDI) and (iPrPZDI) iron methyl complexes revealed significantly different ligand field strengths due to either diminished ligand σ-donation (MeBPDI) or promoted metal π-backbonding (MePZDI). Spin acceleration, leading to fast reductive coupling and catalytic turnover, was promoted in the case of the weaker ligand field and depends on both the nature and position of the electron-withdrawing group. This study provides strong evidence for the role of two-state reactivity in C(sp3)-C(sp3) bond formation and insights on how ligand design either promotes or inhibits spin acceleration in earth-abundant metal catalysis.
Collapse
Affiliation(s)
- Hanna H Cramer
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Coralie Duchemin
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Carli B Kovel
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Junho Kim
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Matthew V Pecoraro
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| | - Paul J Chirik
- Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
| |
Collapse
|
7
|
Török P, Lakk-Bogáth D, Kaizer J. Effect of Redox Potential on Diiron-Mediated Disproportionation of Hydrogen Peroxide. Molecules 2023; 28:molecules28072905. [PMID: 37049667 PMCID: PMC10096046 DOI: 10.3390/molecules28072905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/20/2023] [Accepted: 03/22/2023] [Indexed: 04/14/2023] Open
Abstract
Heme and nonheme dimanganese catalases are widely distributed in living organisms to participate in antioxidant defenses that protect biological systems from oxidative stress. The key step in these processes is the disproportionation of H2O2 to O2 and water, which can be interpreted via two different mechanisms, namely via the formation of high-valent oxoiron(IV) and peroxodimanganese(III) or diiron(III) intermediates. In order to better understand the mechanism of this important process, we have chosen such synthetic model compounds that can be used to map the nature of the catalytically active species and the factors influencing their activities. Our previously reported μ-1,2-peroxo-diiron(III)-containing biomimics are good candidates, as both proposed reactive intermediates (FeIVO and FeIII2(μ-O2)) can be derived from them. Based on this, we have investigated and compared five heterobidentate-ligand-containing model systems including the previously reported and fully characterized [FeII(L1-4)3]2+ (L1 = 2-(2'-pyridyl)-1H-benzimidazole, L2 = 2-(2'-pyridyl)-N-methyl-benzimidazole, L3 = 2-(4-thiazolyl)-1H-benzimidazole and L4 = 2-(4'-methyl-2'-pyridyl)-1H-benzimidazole) and the novel [FeII(L5)3]2+ (L5 = 2-(1H-1,2,4-triazol-3-yl)-pyridine) precursor complexes with their spectroscopically characterized μ-1,2-peroxo-diiron(III) intermediates. Based on the reaction kinetic measurements and previous computational studies, it can be said that the disproportionation reaction of H2O2 can be interpreted through the formation of an electrophilic oxoiron(IV) intermediate that can be derived from the homolysis of the O-O bond of the forming μ-1,2-peroxo-diiron(III) complexes. We also found that the disproportionation rate of the H2O2 shows a linear correlation with the FeIII/FeII redox potential (in the range of 804 mV-1039 mV vs. SCE) of the catalysts controlled by the modification of the ligand environment. Furthermore, it is important to note that the two most active catalysts with L3 and L5 ligands have a high-spin electronic configuration.
Collapse
Affiliation(s)
- Patrik Török
- Research Group of Bioorganic and Biocoordination Chemistry, University of Pannonia, H-8201 Veszprém, Hungary
| | - Dóra Lakk-Bogáth
- Research Group of Bioorganic and Biocoordination Chemistry, University of Pannonia, H-8201 Veszprém, Hungary
| | - József Kaizer
- Research Group of Bioorganic and Biocoordination Chemistry, University of Pannonia, H-8201 Veszprém, Hungary
| |
Collapse
|
8
|
Mitra M, Brinkmeier A, Li Y, Borrell M, Call A, Lloret Fillol J, Richmond MG, Costas M, Nordlander E. An investigation of steric influence on the reactivity of Fe V(O)(OH) tautomers in stereospecific C-H hydroxylation. Dalton Trans 2023; 52:3596-3609. [PMID: 36602022 DOI: 10.1039/d2dt00725h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Two new tetradentate N4 ligands (LN4), LN4 = Me2,Me2PyzTACN (1-(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)-4,7-dimethyl-1,4,7-triazacyclononane) and Me2,MeImTACN (1-((1-methyl-1H-imidazol-1-yl)methyl)-4,7-dimethyl-1,4,7-triazacyclononane) have been synthesized and their corresponding Fe(II) complexes [FeII(Me2,Me2PyzTACN)(CF3SO3)2], 1Pz, and [FeII(Me2,MeImTACN)(CF3SO3)2], 1Im, have been prepared and characterized. Complexes 1Pz and 1Im catalyse the hydroxylation of C-H bonds of alkanes with excellent efficiencies, using hydrogen peroxide as oxidant. The high H/D kinetic isotope effect values for C-H hydroxylation, large normalized tertiary/secondary C-H (C3/C2) bond selectivities in adamantane oxidation, and high degrees of stereoretention in the oxidation of cis-1,2-dimethylcyclohexane are indicative of metal-based oxidation processes. The complexes also catalyse the oxidation of cyclooctene to form its corresponding epoxide and syn-diol. For 1Pz the epoxide is the main product, while for the analogous complex 1Im the syn-diol predominates. The active oxidant is proposed to be an [(LN4)FeV(O)(OH)]2+ species (2Pz, LN4 = Me2,Me2PyzTACN and 2Im, LN4 = Me2,MeImTACN) which may exist in two tautomeric forms related by a proton shift between the oxo and hydroxo ligands. Isotope labelling experiments show that the oxygen atom in the hydroxylated products originates from both water and hydrogen peroxide, and labelling experiments involving oxygen atom transfer to sterically bulky substrates provide indirect information on the steric influence exerted by the two ligands in the relative reactivities of the two hypervalent iron tautomers. Based on these labelling studies, the steric influence exerted by each of the ligands towards the relative reactivity of the oxo ligands of the corresponding pair of Fe(V)(O)(OH) tautomers can be derived. Furthermore, this steric influence can be gauged relative to related complexes/ligands.
Collapse
Affiliation(s)
- Mainak Mitra
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00, Lund, Sweden.
- Department of Chemistry, Burdwan Raj College, Aftab Avenue, W.B. 713104, India
| | - Alexander Brinkmeier
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00, Lund, Sweden.
| | - Yong Li
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00, Lund, Sweden.
| | - Margarida Borrell
- QBIS-CAT, Department of Chemistry and Institut de Quimica Computacional i Catàlisi, University of Girona, Campus Montilivi, E-17071 Girona, Spain.
| | - Arnau Call
- QBIS-CAT, Department of Chemistry and Institut de Quimica Computacional i Catàlisi, University of Girona, Campus Montilivi, E-17071 Girona, Spain.
| | - Julio Lloret Fillol
- Institute of Chemical Research of Catalonia (ICIQ), The Barcelona Institute of Science and Technology, Avinguda Paisos Catalans 16, 43007, Tarragona, Spain
| | - Michael G Richmond
- Department of Chemistry, University of North Texas, Denton, Texas 76203, USA
| | - Miquel Costas
- QBIS-CAT, Department of Chemistry and Institut de Quimica Computacional i Catàlisi, University of Girona, Campus Montilivi, E-17071 Girona, Spain.
| | - Ebbe Nordlander
- Chemical Physics, Department of Chemistry, Lund University, Box 124, SE-221 00, Lund, Sweden.
| |
Collapse
|
9
|
Hüppe HM, Iffland-Mühlhaus L, Heck J, Eilers M, Gildenast H, Schönfeld S, Dürrmann A, Hoffmann A, Weber B, Apfel UP, Herres-Pawlis S. Triflate vs Acetonitrile: Understanding the Iron(II)-Based Coordination Chemistry of Tri(quinolin-8-yl)amine. Inorg Chem 2023; 62:4435-4455. [PMID: 36888965 DOI: 10.1021/acs.inorgchem.2c03890] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
In this study, a synthesis route of tri(quinolin-8-yl)amine (L), a recent member of the tetradentate tris(2-pyridylmethyl)amine (TPA) ligand family, is reported. With the neutral ligand L bound to an iron(II) center in κ4 mode, two cis-oriented coordination sites remain vacant. These can be occupied by coligands such as counterions and solvent molecules. How sensitive this equilibrium can be is most evident if both triflate anions and acetonitrile molecules are available. All three combinations─bis(triflato), bis(acetonitrile), and mixed coligand species─could be characterized by single-crystal X-ray diffraction (SCXRD), which is unique so far for this class of ligand. While at room temperature, the three compounds tend to crystallize concomitantly, the equilibrium can be shifted in favor of the bis(acetonitrile) species by lowering the crystallization temperature. Removed from their mother liquor, the latter is very sensitive to evaporation of the residual solvent, which was observed by powder X-ray diffraction (PXRD) and Mössbauer spectroscopy. The solution behavior of the triflate and acetonitrile species was studied in detail using time- and temperature-resolved UV/vis spectroscopy, Mössbauer spectroscopy of frozen solution, NMR spectroscopy, and magnetic susceptibility measurements. The results indicate a bis(acetonitrile) species in acetonitrile showing a temperature-dependent spin-switching behavior between high- and low-spin. In dichloromethane, the results reveal a high-spin bis(triflato) species. In pursuit of understanding the coordination environment equilibria of the [Fe(L)]2+ complex, a series of compounds with different coligands was prepared and analyzed with SCXRD. The crystal structures indicate that the spin state can be controlled by changing the coordination environment─all of the {N6}-coordinated complexes display geometries expected for low-spin species, while any other donor atom in the coligand position induces a shift to the high-spin state. This fundamental study sheds light on the coligand competition of triflate and acetonitrile, and the high number of crystal structures allows further insights into the influence of different coligands on the geometry and spin state of the complexes.
Collapse
Affiliation(s)
- Henrika M Hüppe
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Linda Iffland-Mühlhaus
- Inorganic Chemistry I, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany
| | - Joshua Heck
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Maverick Eilers
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Hans Gildenast
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Sophie Schönfeld
- Department of Chemistry, Inorganic Chemistry IV, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Andreas Dürrmann
- Department of Chemistry, Inorganic Chemistry IV, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Alexander Hoffmann
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| | - Birgit Weber
- Department of Chemistry, Inorganic Chemistry IV, University of Bayreuth, Universitätsstraße 30, 95447 Bayreuth, Germany
| | - Ulf-Peter Apfel
- Inorganic Chemistry I, Ruhr-Universität Bochum, Universitätsstraße 150, 44801 Bochum, Germany.,Fraunhofer UMSICHT, Osterfelder Straße 3, 46047 Oberhausen, Germany
| | - Sonja Herres-Pawlis
- Institute of Inorganic Chemistry, RWTH Aachen University, Landoltweg 1a, 52074 Aachen, Germany
| |
Collapse
|
10
|
Adam MSS, Elsawy H, Sedky A, Makhlouf MM, Taha A. Catalytic potential of sustainable dinuclear (Cu2+ and ZrO2+) metal organic incorporated frameworks with comprehensive biological studies. J Taiwan Inst Chem Eng 2023. [DOI: 10.1016/j.jtice.2023.104747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
|
11
|
Biologically inspired nonheme iron complex-catalyzed cis-dihydroxylation of alkenes modeling Rieske dioxygenases. Coord Chem Rev 2023. [DOI: 10.1016/j.ccr.2022.214945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
12
|
Mekhail MA, Pota K, Kharel S, Freire DM, Green KN. Pyridine modifications regulate the electronics and reactivity of Fe-pyridinophane complexes. Dalton Trans 2023; 52:892-901. [PMID: 36537287 PMCID: PMC10903111 DOI: 10.1039/d2dt03485a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
12-Membered pyridinophanes are the focus of many studies as biological mimics, chelators, and catalytic precursors. Therefore, the desire to tune the reactivity of pyridinophanes to better control the applications of derivative metal complexes has inspired many structure-activity relationship studies. However, the separation of structural versus electronic changes imparted by ligand modification has made these structure-activity relationship studies of transition metal catalysts challenging to define. In this work we show that 4-substitution of the pyridine ring in 12-membered tetra-aza pyridinophanes successfully provides a regulatory handle on the electronic properties of the metal center and, therefore, the catalytic C-C coupling activity of the respective iron complexes. The C-C coupling reaction catalyzed by Fe(L1-L6) provides a range of yields (32-58%) that directly correlate with iron redox potentials (ΔE1/2 = 152 mV) and metal binding constants (Δlog β = 3.45), while the geometry of the complexes was virtually indistinguishable. These are the first results to definitively show the redox potential and metal binding as independent properties from the coordination chemistry in one ligand series. Adjustments to these chemical properties were then shown to provide a regulatory handle for the C-C coupling reactivity tuned via pyridine substitution in pyridinophanes.
Collapse
Affiliation(s)
- Magy A Mekhail
- Department of Chemistry and Biochemistry, Texas Christian University, Fort Worth, Texas 76129, USA.
| | - Kristof Pota
- Department of Chemistry and Biochemistry, Texas Christian University, Fort Worth, Texas 76129, USA.
| | - Sugam Kharel
- Department of Chemistry and Biochemistry, Texas Christian University, Fort Worth, Texas 76129, USA.
| | - David M Freire
- Department of Chemistry and Biochemistry, Texas Christian University, Fort Worth, Texas 76129, USA.
| | - Kayla N Green
- Department of Chemistry and Biochemistry, Texas Christian University, Fort Worth, Texas 76129, USA.
| |
Collapse
|
13
|
Dantignana V, Pérez-Segura MC, Besalú-Sala P, Delgado-Pinar E, Martínez-Camarena Á, Serrano-Plana J, Álvarez-Núñez A, Castillo CE, García-España E, Luis JM, Basallote MG, Costas M, Company A. Characterization of a Ferryl Flip in Electronically Tuned Nonheme Complexes. Consequences in Hydrogen Atom Transfer Reactivity. Angew Chem Int Ed Engl 2023; 62:e202211361. [PMID: 36305539 PMCID: PMC10107328 DOI: 10.1002/anie.202211361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Indexed: 12/04/2022]
Abstract
Two oxoiron(IV) isomers (R 2a and R 2b) of general formula [FeIV (O)(R PyNMe3 )(CH3 CN)]2+ are obtained by reaction of their iron(II) precursor with NBu4 IO4 . The two isomers differ in the position of the oxo ligand, cis and trans to the pyridine donor. The mechanism of isomerization between R 2a and R 2b has been determined by kinetic and computational analyses uncovering an unprecedented path for interconversion of geometrical oxoiron(IV) isomers. The activity of the two oxoiron(IV) isomers in hydrogen atom transfer (HAT) reactions shows that R 2a reacts one order of magnitude faster than R 2b, which is explained by a repulsive noncovalent interaction between the ligand and the substrate in R 2b. Interestingly, the electronic properties of the R substituent in the ligand pyridine ring do not have a significant effect on reaction rates. Overall, the intrinsic structural aspects of each isomer define their relative HAT reactivity, overcoming changes in electronic properties of the ligand.
Collapse
Affiliation(s)
- Valeria Dantignana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - M Carmen Pérez-Segura
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Pau Besalú-Sala
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Estefanía Delgado-Pinar
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Álvaro Martínez-Camarena
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Joan Serrano-Plana
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Andrea Álvarez-Núñez
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Carmen E Castillo
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Enrique García-España
- Departamento de Química Inorgánica, Instituto de Ciencia Molecular (ICMol), Universidad de Valencia, C/Catedrático José Beltrán, Paterna, 46980, Valencia 2, Spain
| | - Josep M Luis
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Manuel G Basallote
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, 11510, Cádiz, Spain
| | - Miquel Costas
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| | - Anna Company
- Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, C/Mª Aurèlia Capmany 69, 17003, Girona, Catalonia, Spain
| |
Collapse
|
14
|
Comprehensive catalytic and biological studies on new designed oxo- and dioxo-metal (IV/VI) organic arylhydrazone frameworks. J Mol Liq 2023. [DOI: 10.1016/j.molliq.2023.121309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
|
15
|
Adam MSS, Abdel-Rahman OS, Makhlouf MM. Metal ion induced changes in the structure of Schiff base hydrazone chelates and their reactivity effect on catalytic benzyl alcohol oxidation and biological assays. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2022.134164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
16
|
Dey B, Mehta S, Mondal A, Cirera J, Colacio E, Chandrasekhar V. Push and Pull Effect of Methoxy and Nitro Groups Modifies the Spin-State Switching Temperature in Fe(III) Complexes. ACS OMEGA 2022; 7:39268-39279. [PMID: 36340084 PMCID: PMC9631739 DOI: 10.1021/acsomega.2c05380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2022] [Accepted: 09/29/2022] [Indexed: 06/16/2023]
Abstract
We have explored the impact of electron-donating (methoxy) and electron-withdrawing (nitro) substituents on SalEen ligand based spin crossover (SCO) behavior of Fe(III) complexes. Thus, 3-X-substituted SalEen ligands were employed to prepare [Fe(3-X-SalEen)2]·NCSe, where X = OMe (1), H (2), and NO2 (3) (3-X-SalEen is the condensation product of 3-substituted salicylaldehyde and N-ethylethylenediamine). The characteristic spin transition temperature (T 1/2) is shown to shift to a lower temperature when an electron-donating substituent (OMe) is used and to a higher temperature when an electron-withdrawing substituent (NO2) is used. We used experimental and theoretical methods to determine the reasons for this behavior. The solid-state magnetic data revealed the transition temperatures for complexes 1, 2, and 3 to be 219, 251, and 366 K, respectively. The solution-state magnetic data also support this trend in T 1/2 values. UV-vis spectra analysis indicates that there is greater delocalization in the π-manifold of the ligand when the nitro group is the substituent. Theoretical studies through density functional theory methods suggest the methoxy substituent decreases the energy gap between the t2g and eg orbitals (explaining the lower T 1/2 value), while the nitro substituent increases the energy gap between the t2g and eg orbitals and thus increases the T 1/2 value.
Collapse
Affiliation(s)
- Bijoy Dey
- Tata
Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad500107, India
| | - Sakshi Mehta
- Solid
State and Structural Chemistry Unit, Indian
Institute of Science, Sir C V Raman Road, Bangalore, Karnataka560012, India
| | - Abhishake Mondal
- Solid
State and Structural Chemistry Unit, Indian
Institute of Science, Sir C V Raman Road, Bangalore, Karnataka560012, India
| | - Jordi Cirera
- Departament
de Química Inorgànica i Orgànica and Institut
de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028Barcelona, Spain
| | - Enrique Colacio
- Departamento
de Química Inorgánica, Facultad de Ciencias, Universidad de Granada, 18071Granada, Spain
| | - Vadapalli Chandrasekhar
- Tata
Institute of Fundamental Research Hyderabad, Gopanpally, Hyderabad500107, India
- Department
of Chemistry, Indian Institute of Technology
Kanpur, Kanpur, Uttar Pradesh208016, India
| |
Collapse
|
17
|
Bondì L, Garden AL, Totti F, Jerabek P, Brooker S. Quantitative Assessment of Ligand Substituent Effects on σ‐ and π‐Contributions to Fe−N Bonds in Spin Crossover Fe
II
Complexes. Chemistry 2022; 28:e202104314. [PMID: 35224791 PMCID: PMC9310619 DOI: 10.1002/chem.202104314] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Indexed: 11/24/2022]
Abstract
The effect of para‐substituent X on the electronic structure of sixteen tridentate 4‐X‐(2,6‐di(pyrazol‐1‐yl))‐pyridine (bppX) ligands and the corresponding solution spin crossover [FeII(bppX)2]2+ complexes is analysed further, to supply quantitative insights into the effect of X on the σ‐donor and π‐acceptor character of the Fe‐NA(pyridine) bonds. EDA‐NOCV on the sixteen LS complexes revealed that neither ΔEorb,σ+π (R2=0.48) nor ΔEorb,π (R2=0.31) correlated with the experimental solution T1/2 values (which are expected to reflect the ligand field imposed on the iron centre), but that ΔEorb,σ correlates well (R2=0.82) and implies that as X changes from EDG→EWG (Electron Donating to Withdrawing Group), the ligand becomes a better σ‐donor. This counter‐intuitive result was further probed by Mulliken analysis of the NA atomic orbitals: NA(px) involved in the Fe−N σ‐bond vs. the perpendicular NA(pz) employed in the ligand aromatic π‐system. As X changes EDG→EWG, the electron population on NA(pz) decreases, making it a better π‐acceptor, whilst that in NA(px) increases, making it a better σ‐bond donor; both increase ligand field, and T1/2 as observed. In 2016, Halcrow, Deeth and co‐workers proposed an intuitively reasonable explanation of the effect of the para‐X substituents on the T1/2 values in this family of complexes, consistent with the calculated MO energy levels, that M→L π‐backdonation dominates in these M−L bonds. Here the quantitative EDA‐NOCV analysis of the M−L bond contributions provides a more complete, coherent and detailed picture of the relative impact of M−L σ‐versus π‐bonding in determining the observed T1/2, refining the earlier interpretation and revealing the importance of the σ‐bonding. Furthermore, our results are in perfect agreement with the ΔE(HS‐LS) vs. σp+(X) correlation reported in their work.
Collapse
Affiliation(s)
- Luca Bondì
- Department of Chemistry MacDiarmid Institute of Advanced Materials and Nanotechnology University of Otago PO Box 56 Dunedin 9054 New Zealand
- Department of Chemistry ‘Ugo Schiff' and INSTM Research Unit University of Florence 50019 Sesto Fiorentino Italy
| | - Anna L. Garden
- Department of Chemistry MacDiarmid Institute of Advanced Materials and Nanotechnology University of Otago PO Box 56 Dunedin 9054 New Zealand
| | - Federico Totti
- Department of Chemistry ‘Ugo Schiff' and INSTM Research Unit University of Florence 50019 Sesto Fiorentino Italy
| | - Paul Jerabek
- Institute of Hydrogen Technology Helmholtz-Zentrum Hereon Max-Planck-Straße 1 21502 Geesthacht Germany
| | - Sally Brooker
- Department of Chemistry MacDiarmid Institute of Advanced Materials and Nanotechnology University of Otago PO Box 56 Dunedin 9054 New Zealand
| |
Collapse
|
18
|
Walleck S, Zimmermann TP, Hachmeister H, Pilger C, Huser T, Katz S, Hildebrandt P, Stammler A, Bögge H, Bill E, Glaser T. Generation of a μ-1,2-hydroperoxo Fe IIIFe III and a μ-1,2-peroxo Fe IVFe III Complex. Nat Commun 2022; 13:1376. [PMID: 35296656 PMCID: PMC8927127 DOI: 10.1038/s41467-022-28894-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 02/17/2022] [Indexed: 12/05/2022] Open
Abstract
μ-1,2-Peroxo-diferric intermediates (P) of non-heme diiron enzymes are proposed to convert upon protonation either to high-valent active species or to activated P′ intermediates via hydroperoxo-diferric intermediates. Protonation of synthetic μ-1,2-peroxo model complexes occurred at the μ-oxo and not at the μ-1,2-peroxo bridge. Here we report a stable μ-1,2-peroxo complex {FeIII(μ-O)(μ-1,2-O2)FeIII} using a dinucleating ligand and study its reactivity. The reversible oxidation and protonation of the μ-1,2-peroxo-diferric complex provide μ-1,2-peroxo FeIVFeIII and μ-1,2-hydroperoxo-diferric species, respectively. Neither the oxidation nor the protonation induces a strong electrophilic reactivity. Hence, the observed intramolecular C-H hydroxylation of preorganized methyl groups of the parent μ-1,2-peroxo-diferric complex should occur via conversion to a more electrophilic high-valent species. The thorough characterization of these species provides structure-spectroscopy correlations allowing insights into the formation and reactivities of hydroperoxo intermediates in diiron enzymes and their conversion to activated P′ or high-valent intermediates. Iron coordination complexes can be used to gain insight on biologically relevant iron-oxygen compounds generated in iron metalloenzymes. Here, the authors characterise a μ-1,2-hydroperoxo FeIIIFeIII and a μ-1,2-peroxo FeIVFeIII, and study their reactivity in C-H activation.
Collapse
Affiliation(s)
- Stephan Walleck
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615, Bielefeld, Germany
| | - Thomas Philipp Zimmermann
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615, Bielefeld, Germany
| | - Henning Hachmeister
- Biomolekulare Photonik, Fakultät für Physik, Universität Bielefeld, Universitätsstr. 25, D-33615, Bielefeld, Germany
| | - Christian Pilger
- Biomolekulare Photonik, Fakultät für Physik, Universität Bielefeld, Universitätsstr. 25, D-33615, Bielefeld, Germany
| | - Thomas Huser
- Biomolekulare Photonik, Fakultät für Physik, Universität Bielefeld, Universitätsstr. 25, D-33615, Bielefeld, Germany
| | - Sagie Katz
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, D-10623, Berlin, Germany
| | - Peter Hildebrandt
- Institut für Chemie, Technische Universität Berlin, Straße des 17. Juni 135, D-10623, Berlin, Germany
| | - Anja Stammler
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615, Bielefeld, Germany
| | - Hartmut Bögge
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615, Bielefeld, Germany
| | - Eckhard Bill
- Max-Planck-Institut für Chemische Energiekonversion, Stiftstr. 34-36, D-45470, Mülheim an der Ruhr, Germany
| | - Thorsten Glaser
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie, Universität Bielefeld, Universitätsstr. 25, D-33615, Bielefeld, Germany.
| |
Collapse
|
19
|
El‐Sayed NMA, Elsawy H, Adam MSS. Polar and nonpolar iron (II) complexes of isatin hydrazone derivatives as effective catalysts in oxidation reactions and their antimicrobial and anticancer activities. Appl Organomet Chem 2022. [DOI: 10.1002/aoc.6662] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
| | - Hany Elsawy
- Department of Chemistry College of Science, King Faisal University Al‐Ahsa Saudi Arabia
- Department of Chemistry, Faculty of Science Tanta University Tanta Egypt
| | - Mohamed Shaker S. Adam
- Department of Chemistry College of Science, King Faisal University Al‐Ahsa Saudi Arabia
- Chemistry Department, Faculty of Science Sohag University Sohag Egypt
| |
Collapse
|
20
|
Livesay BN, Shores MP. Influence of Coordinated Triflate Anions on the Solution Magnetic Properties of a Neutral Iron(II) Complex. Inorg Chem 2021; 60:15445-15455. [PMID: 34596394 DOI: 10.1021/acs.inorgchem.1c02112] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In an effort to probe the impacts of speciation on spin-state switching, the synthesis and unique solution-phase magnetic properties of [((TIPSC≡C)3tren)Fe(OTf)2] (1) are described. Analysis of the single-crystal X-ray diffraction data shows that the tris(iminoalkyne) ligand coordinates to the iron(II) center through all four nitrogen atoms, while the other two coordination sites are filled by the oxygen atoms from triflate anions. Solid-state variable-temperature (VT) magnetic studies show that 1 remains high-spin (HS) at all temperatures. In the presence of moderately strong coordinating solvents, solvent replaces the two bound triflate counteranions, as observed by 19F NMR spectroscopy and supported by conductivity measurements. VT solution measurements show 1 to be in the HS state when this solvent is oxygen-donating but low-spin (LS) with a nitrogen-donating solvent. In the noncoordinating solvent dichloromethane, both triflates are bound to the iron(II) center at room temperature, but upon cooling, 1 undergoes a coordination change, resulting in the loss of one triflate, as shown by 19F NMR. With the moderately coordinating solvent acetone, triflate dissociation upon cooling results in a spin-switching species with a T1/2 value of 171 K, characterized via 19F NMR, Evans' method, and solution magnetometry measurements. Solution magnetic measurements collected in structurally similar cyclopentanone suggest that the spin-state switching event is exclusive to the acetone environment, suggesting the influence of both the local coordination environment and aggregation. Additionally, a comparison of the solvodoynamic diameters via dynamic light scattering suggests that aggregation of 1 is significantly different in (CH3)2CO and (CD3)2CO, leading to the observation of spin-switching behavior in the former and fully HS behavior in the latter. This study highlights the sensitivity of solution magnetic properties to solvent choice.
Collapse
Affiliation(s)
- Brooke N Livesay
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Matthew P Shores
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| |
Collapse
|
21
|
Shahid N, Burrows KE, Howard MJ, Pask CM, Cespedes O, McGowan PC, Halcrow MA. Spin-States of Diastereomeric Iron(II) Complexes of 2,6-Bis(thiazolin-2-yl)pyridine (ThioPyBox) Ligands and a Comparison with the Corresponding PyBox Derivatives. Inorg Chem 2021; 60:14336-14348. [PMID: 34472842 DOI: 10.1021/acs.inorgchem.1c01988] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
This report investigates homoleptic iron(II) complexes of thiazolinyl analogues of chiral PyBox tridentate ligands: 2,6-bis(4-phenyl-4,5-dihydrothiazol-2-yl)pyridine (L1Ph), 2,6-bis(4-isopropyl-4,5-dihydrothiazol-2-yl)pyridine (L1iPr), and 2,6-bis(4-tert-butyl-4,5-dihydrothiazol-2-yl)pyridine (L1t-Bu). Crystallographic data imply the larger and more flexible thiazolinyl rings reduce steric clashes between the R substituents in homochiral [Fe((R)-L1R)2]2+ or [Fe((S)-L1R)2]2+ (R = Ph, iPr, or t-Bu), compared to their PyBox (L2R) analogues. Conversely, the larger heterocyclic S atoms are in close contact with the R substituents in heterochiral [Fe((R)-L1Ph)((S)-L1Ph)]2+, giving it a more sterically hindered ligand environment than that in [Fe((R)-L2Ph)((S)-L2Ph)]2+ (L2Ph = 2,6-bis(4-phenyl-4,5-dihydrooxazol-2-yl)pyridine). Preformed [Fe((R)-L1Ph)((S)-L1Ph)]2+ and [Fe((R)-L1iPr)((S)-L1iPr)]2+ do not racemize by ligand redistribution in CD3CN solution, but homochiral [Fe(L1iPr)2]2+ and [Fe(L1t-Bu)2]2+ both undergo partial ligand displacement in that solvent. Homochiral [Fe(L1Ph)2]2+ and [Fe(L1iPr)2]2+ exhibit spin-crossover equilibria in CD3CN, centered at 344 ± 6 K and 277 ± 1 K respectively, while their heterochiral congeners are essentially low-spin within the liquid range of the solvent. These data imply that the diastereomers of [Fe(L1Ph)2]2+ and [Fe(L1iPr)2]2+ show a greater difference in their spin-state behaviors than was previous found for [Fe(L2Ph)2]2+. Gas-phase DFT calculations (B86PW91/def2-SVP) of the [Fe(L1R)2]2+ and [Fe(L2R)2]2+ complexes reproduce most of the observed trends, but they overstabilize the high-spin state of SCO-active [Fe(L1iPr)2]2+ by ca. 1.5 kcal mol-1. This might reflect the influence of intramolecular dispersion interactions on the spin states of these compounds. Attempts to model this with the dispersion-corrected functionals B97-D2 or PBE-D3 were less successful than our original protocol, confirming that the spin states of sterically hindered molecules are a challenging computational problem.
Collapse
Affiliation(s)
- Namrah Shahid
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Kay E Burrows
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Mark J Howard
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Christopher M Pask
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Oscar Cespedes
- School of Physics and Astronomy, University of Leeds, E. C. Stoner Building, Leeds LS2 9JT, United Kingdom
| | - Patrick C McGowan
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| | - Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, United Kingdom
| |
Collapse
|
22
|
Janetzki JT, Zahir FZM, Gable RW, Phonsri W, Murray KS, Goerigk L, Boskovic C. A Convenient DFT-Based Strategy for Predicting Transition Temperatures of Valence Tautomeric Molecular Switches. Inorg Chem 2021; 60:14475-14487. [PMID: 34494829 DOI: 10.1021/acs.inorgchem.1c02273] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The ability to identify promising candidate switchable molecules computationally, prior to synthesis, represents a considerable advance in the development of switchable molecular materials. Even more useful would be the possibility of predicting the switching temperature. Cobalt-dioxolene complexes can exhibit thermally induced valence tautomeric switching between low-spin CoIII-catecholate and high-spin CoII-semiquinonate forms, where the half-temperature (T1/2) is the temperature at which there are equal amounts of the two tautomers. We report the first simple computational strategy for accurately predicting T1/2 values for valence tautomeric complexes. Dispersion-corrected density functional theory (DFT) methods have been applied to the [Co(dbdiox)(dbsq)(N2L)] (dbdiox/dbsq•- = 3,5-di-tert-butyldioxolene/semiquinonate; N2L = diimine) family of valence tautomeric complexes, including the newly reported [Co(dbdiox)(dbsq)(MeO-bpy)] (1) (MeO-bpy = 4,4'-dimethoxy-2,2'-bipyridine). The DFT strategy has been thoroughly benchmarked to experimental data, affording highly accurate spin-distributions and an excellent energy match between experimental and calculated spin-states. Detailed orbital analysis of the [Co(dbdiox)(dbsq)(N2L)] complexes has revealed that the diimine ligand tunes the T1/2 value primarily through π-acceptance. We have established an excellent correlation between experimental T1/2(toluene) values for [Co(dbdiox)(dbsq)(N2L)] complexes and the calculated lowest unoccupied molecular orbital energy of the corresponding diimine ligand. The model affords accurate T1/2(toluene) values for [Co(dbdiox)(dbsq)(N2L)] complexes, with an average error of only 3.7%. This quantitative and simple DFT strategy allows experimentalists to not only rapidly identify proposed VT complexes but also predict the transition temperature. This study lays the groundwork for future in silico screening of candidate switchable molecules prior to experimental investigation, with associated time, cost, and environmental benefits.
Collapse
Affiliation(s)
- Jett T Janetzki
- School of Chemistry, University of Melbourne, Victoria 3010, Australia
| | - F Zahra M Zahir
- School of Chemistry, University of Melbourne, Victoria 3010, Australia
| | - Robert W Gable
- School of Chemistry, University of Melbourne, Victoria 3010, Australia
| | - Wasinee Phonsri
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Keith S Murray
- School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Lars Goerigk
- School of Chemistry, University of Melbourne, Victoria 3010, Australia
| | - Colette Boskovic
- School of Chemistry, University of Melbourne, Victoria 3010, Australia
| |
Collapse
|
23
|
Shteinman AA, Mitra M. Nonheme mono- and dinuclear iron complexes in bio-inspired C H and C C bond hydroxylation reactions: Mechanistic insight. Inorganica Chim Acta 2021. [DOI: 10.1016/j.ica.2021.120388] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
|
24
|
Mukherjee G, Satpathy JK, Bagha UK, Mubarak MQE, Sastri CV, de Visser SP. Inspiration from Nature: Influence of Engineered Ligand Scaffolds and Auxiliary Factors on the Reactivity of Biomimetic Oxidants. ACS Catal 2021. [DOI: 10.1021/acscatal.1c01993] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Gourab Mukherjee
- Department of Chemistry, Indian Institute of Technology Guwahati, 781039, Assam, India
| | - Jagnyesh K. Satpathy
- Department of Chemistry, Indian Institute of Technology Guwahati, 781039, Assam, India
| | - Umesh K. Bagha
- Department of Chemistry, Indian Institute of Technology Guwahati, 781039, Assam, India
| | - M. Qadri E. Mubarak
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Fakulti Sains dan Teknologi, Universiti Sains Islam Malaysia, Bandar Baru Nilai, 71800 Nilai, Negeri Sembilan Malaysia
| | - Chivukula V. Sastri
- Department of Chemistry, Indian Institute of Technology Guwahati, 781039, Assam, India
| | - Sam P. de Visser
- Department of Chemistry, Indian Institute of Technology Guwahati, 781039, Assam, India
- Manchester Institute of Biotechnology, The University of Manchester, 131 Princess Street, Manchester M1 7DN, United Kingdom
- Department of Chemical Engineering and Analytical Science, The University of Manchester, Oxford Road, Manchester M13 9PL, United Kingdom
| |
Collapse
|
25
|
Sun L, Rotaru A, Robeyns K, Garcia Y. A Colorimetric Sensor for the Highly Selective, Ultra-sensitive, and Rapid Detection of Volatile Organic Compounds and Hazardous Gases. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c01389] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Li Sun
- Institute of Condensed Matter and Nanosciences, Molecular Chemistry, Materials and Catalysis (IMCN/MOST), Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| | - Aurelian Rotaru
- Department of Electrical Engineering and Computer Science and MANSiD Research Center, “Stefan cel Mare” University, University Street, 13, Suceava 720229, Romania
| | - Koen Robeyns
- Institute of Condensed Matter and Nanosciences, Molecular Chemistry, Materials and Catalysis (IMCN/MOST), Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| | - Yann Garcia
- Institute of Condensed Matter and Nanosciences, Molecular Chemistry, Materials and Catalysis (IMCN/MOST), Université Catholique de Louvain, Louvain-la-Neuve 1348, Belgium
| |
Collapse
|
26
|
Kulmaczewski R, Howard MJ, Halcrow MA. Influence of ligand substituent conformation on the spin state of an iron(II)/di(pyrazol-1-yl)pyridine complex. Dalton Trans 2021; 50:3464-3467. [PMID: 33660725 DOI: 10.1039/d1dt00590a] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The temperature of the solution-phase spin-crossover equilibrium in iron(ii) complexes of 4-alkylsulfanyl-2,6-di{pyrazol-1-yl}pyridine (bppSR) complexes depends strongly on the alkylsulfanyl substituent. DFT calculations imply this reflects the conformation of the alkylsulfanyl groups, which lie perpendicular to the heterocyclic ligand donors in [Fe(bppStBu)2]2+ but are oriented co-planar with the ligand core for smaller SR substituents.
Collapse
Affiliation(s)
- Rafal Kulmaczewski
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT.
| | - Mark J Howard
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT.
| | - Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT.
| |
Collapse
|
27
|
Castillo CE, Gamba I, Vicens L, Clémancey M, Latour JM, Costas M, Basallote MG. Spin State Tunes Oxygen Atom Transfer towards Fe IV O Formation in Fe II Complexes. Chemistry 2021; 27:4946-4954. [PMID: 33350013 DOI: 10.1002/chem.202004921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Indexed: 11/08/2022]
Abstract
Oxoiron(IV) complexes bearing tetradentate ligands have been extensively studied as models for the active oxidants in non-heme iron-dependent enzymes. These species are commonly generated by oxidation of their ferrous precursors. The mechanisms of these reactions have seldom been investigated. In this work, the reaction kinetics of complexes [FeII (CH3 CN)2 L](SbF6 )2 ([1](SbF6 )2 and [2](SbF6 )2 ) and [FeII (CF3 SO3 )2 L] ([1](OTf)2 and [2](OTf)2 (1, L=Me,H Pytacn; 2, L=nP,H Pytacn; R,R' Pytacn=1-[(6-R'-2-pyridyl)methyl]-4,7- di-R-1,4,7-triazacyclononane) with Bu4 NIO4 to form the corresponding [FeIV (O)(CH3 CN)L]2+ (3, L=Me,H Pytacn; 4, L=nP,H Pytacn) species was studied in acetonitrile/acetone at low temperatures. The reactions occur in a single kinetic step with activation parameters independent of the nature of the anion and similar to those obtained for the substitution reaction with Cl- as entering ligand, which indicates that formation of [FeIV (O)(CH3 CN)L]2+ is kinetically controlled by substitution in the starting complex to form [FeII (IO4 )(CH3 CN)L]+ intermediates that are converted rapidly to oxo complexes 3 and 4. The kinetics of the reaction is strongly dependent on the spin state of the starting complex. A detailed analysis of the magnetic susceptibility and kinetic data for the triflate complexes reveals that the experimental values of the activation parameters for both complexes are the result of partial compensation of the contributions from the thermodynamic parameters for the spin-crossover equilibrium and the activation parameters for substitution. The observation of these opposite and compensating effects by modifying the steric hindrance at the ligand illustrates so far unconsidered factors governing the mechanism of oxygen atom transfer leading to high-valent iron oxo species.
Collapse
Affiliation(s)
- Carmen E Castillo
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, Cádiz, 11510, Spain
| | - Ilaria Gamba
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Laia Vicens
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Martin Clémancey
- CEA, CNRS, IRIG, DIESE, LCBM, Université Grenoble Alpes, pmb, 38000, Grenoble, France
| | - Jean-Marc Latour
- CEA, CNRS, IRIG, DIESE, LCBM, Université Grenoble Alpes, pmb, 38000, Grenoble, France
| | - Miquel Costas
- Grup de Química Bioinspirada, Supramolecular i Catàlisi (QBIS-CAT), Institut de Química Computacional i Catàlisi (IQCC), Departament de Química, Universitat de Girona, Campus de Montilivi, Girona, 17071, Catalonia, Spain
| | - Manuel G Basallote
- Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica, y Química Inorgánica, Facultad de Ciencias, Instituto de Biomoléculas (INBIO), Universidad de Cádiz, Puerto Real, Cádiz, 11510, Spain
| |
Collapse
|
28
|
Wang RG, Meng YS, Gao FF, Gao WQ, Liu CH, Li A, Liu T, Zhu YY. Ligand symmetry significantly affects spin crossover behaviour in isomeric [Fe(pybox) 2] 2+ complexes. Dalton Trans 2021; 50:3369-3378. [PMID: 33595584 DOI: 10.1039/d0dt03978k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The understanding of the correlation between the spin-state behaviour and the structural features in transition-metal complexes is of pronounced importance to the design of spin crossover compounds with high performance. However, the study of the influence of ligand symmetry on the spin crossover properties is still limited due to the shortage of suitable structural systems. Herein we report the magneto-structural correlations of three mononuclear Fe(ii) isomers with respect to their ligand symmetry. In this work, two phenyl-substituted meso and optically pure pybox ligands were employed to construct meso (1), optically pure (2), and racemic (3) ligand types of [Fe(pybox)2]2+ complexes. Their magnetic susceptibilities were measured via temperature-dependent paramagnetic 1H NMR spectroscopy. We fitted the midpoint temperatures of the transition (T1/2) of 260 K for 1(ClO4), 247 K for 2(ClO4), and 281 K for 3(ClO4). The influence of structural symmetry on spin crossover was rationalized through density functional theory calculations. The optimized structures of [Fe(pybox)2]2+ complex cations show that the geometric distortion of the central FeN6 coordination sphere is mainly caused by the steric congestions between adjacent phenyl substituents. In these compounds, there is a distinct correlation that more steric congestions produce larger coordination distortion and favor the electron configuration in the high-spin state, which reflects in the increase of T1/2. Additionally, the influence of the counter anion and lattice solvent on the meso series compounds was inspected. It is revealed that multiple factors dominate the spin-state behaviour in the solid state. This work provides deep insight into the effect of ligand symmetry on the spin transition behaviour in spin crossover compounds. It demonstrates that molecular symmetry should be considered in the design of spin crossover compounds.
Collapse
Affiliation(s)
- Run-Guo Wang
- School of Chemistry and Chemical Engineering, Anhui Key Laboratory of Advanced Catalytic Materials and Reaction Engineering, Hefei University of Technology, Hefei 230009, China.
| | | | | | | | | | | | | | | |
Collapse
|
29
|
Achard T, Bellemin‐Laponnaz S. Recent Advances on Catalytic Osmium‐Free Olefin
syn
‐Dihydroxylation. European J Org Chem 2021. [DOI: 10.1002/ejoc.202001209] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Thierry Achard
- Département des Matériaux Organiques Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) Université de Strasbourg CNRS UMR‐7504 23 rue du Loess, BP 43 67034 Strasbourg Cedex 2 France
| | - Stéphane Bellemin‐Laponnaz
- Département des Matériaux Organiques Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS) Université de Strasbourg CNRS UMR‐7504 23 rue du Loess, BP 43 67034 Strasbourg Cedex 2 France
| |
Collapse
|
30
|
Bondì L, Rodríguez-Jiménez S, Feltham HLC, Garden AL, Brooker S. Probing the generality of spin crossover complex T½vs. ligand 15N NMR chemical shift correlations: towards predictable tuning. Inorg Chem Front 2021. [DOI: 10.1039/d1qi00919b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A study of 6 families (42 members) demonstrates that within a family the easily calculated 15N-NMR values of ligands enable predictable tuning of T1/2 in the corresponding complexes, except for 2 families with weakly influencing meta-substituents.
Collapse
Affiliation(s)
- Luca Bondì
- Department of Chemistry and the MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
- Department of Chemistry ‘Ugo Schiff’ and INSTM Research Unit, University of Florence, 50019 Sesto Fiorentino, Italy
| | - Santiago Rodríguez-Jiménez
- Department of Chemistry and the MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Humphrey L. C. Feltham
- Department of Chemistry and the MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Anna L. Garden
- Department of Chemistry and the MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - Sally Brooker
- Department of Chemistry and the MacDiarmid Institute for Advanced Materials and Nanotechnology, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| |
Collapse
|
31
|
Milocco F, de Vries F, Bartels IMA, Havenith RWA, Cirera J, Demeshko S, Meyer F, Otten E. Electronic Control of Spin-Crossover Properties in Four-Coordinate Bis(formazanate) Iron(II) Complexes. J Am Chem Soc 2020; 142:20170-20181. [PMID: 33197175 PMCID: PMC7705964 DOI: 10.1021/jacs.0c10010] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
![]()
The
transition between spin states in d-block metal complexes has
important ramifications for their structure and reactivity, with applications
ranging from information storage materials to understanding catalytic
activity of metalloenzymes. Tuning the ligand field (ΔO) by steric and/or electronic effects has provided spin-crossover
compounds for several transition metals in the periodic table, but
this has mostly been limited to coordinatively saturated metal centers
in octahedral ligand environments. Spin-crossover complexes with low
coordination numbers are much rarer. Here we report a series of four-coordinate,
(pseudo)tetrahedral Fe(II) complexes with formazanate ligands and
demonstrate how electronic substituent effects can be used to modulate
the thermally induced transition between S = 0 and S = 2 spin states in solution. All six compounds undergo
spin-crossover in solution with T1/2 above
room temperature (300–368 K). While structural analysis by
X-ray crystallography shows that the majority of these compounds are
low-spin in the solid state (and remain unchanged upon heating), we
find that packing effects can override this preference and give rise
to either rigorously high-spin (6) or gradual spin-crossover
behavior (5) also in the solid state. Density functional
theory calculations are used to delineate the empirical trends in
solution spin-crossover thermodynamics. In all cases, the stabilization
of the low-spin state is due to the π-acceptor properties of
the formazanate ligand, resulting in an “inverted” ligand
field, with an approximate “two-over-three” splitting
of the d-orbitals and a high degree of metal–ligand covalency
due to metal → ligand π-backdonation. The computational
data indicate that the electronic nature of the para-substituent has a different influence depending on whether it is
present at the C–Ar or N–Ar rings, which is ascribed
to the opposing effect on metal–ligand σ- and π-bonding.
Collapse
Affiliation(s)
- Francesca Milocco
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Folkert de Vries
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Imke M A Bartels
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Remco W A Havenith
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.,Ghent Quantum Chemistry Group, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281 (S3), B-9000 Gent, Belgium
| | - Jordi Cirera
- Departament de Química Inorgànica i Orgànica and Institut de Recerca de Química Teòrica i Computacional, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain
| | - Serhiy Demeshko
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
| | - Franc Meyer
- Institut für Anorganische Chemie, Universität Göttingen, Tammannstraße 4, 37077 Göttingen, Germany
| | - Edwin Otten
- Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| |
Collapse
|
32
|
Bondì L, Garden AL, Jerabek P, Totti F, Brooker S. Quantitative and Chemically Intuitive Evaluation of the Nature of M-L Bonds in Paramagnetic Compounds: Application of EDA-NOCV Theory to Spin Crossover Complexes. Chemistry 2020; 26:13677-13685. [PMID: 32671882 PMCID: PMC7702084 DOI: 10.1002/chem.202002146] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2020] [Revised: 06/25/2020] [Indexed: 11/16/2022]
Abstract
To improve understanding of M-L bonds in 3d transition metal complexes, analysis by energy decomposition analysis and natural orbital for chemical valence model (EDA-NOCV) is desirable as it provides a full, quantitative and chemically intuitive ab initio description of the M-L interactions. In this study, a generally applicable fragmentation and computational protocol was established and validated by using octahedral spin crossover (SCO) complexes, as the transition temperature (T1/2 ) is sensitive to subtle changes in M-L bonding. Specifically, EDA-NOCV analysis of Fe-N bonds in five [FeII (Lazine )2 (NCBH3 )2 ], in both low-spin (LS) and paramagnetic high-spin (HS) states led to: 1) development of a general, widely applicable, corrected M+L6 fragmentation, tested against a family of five LS [FeII (Lazine )3 ](BF4 )2 complexes; this confirmed that three Lazine are stronger ligands (ΔEorb,σ+π =-370 kcal mol-1 ) than 2 Lazine +2 NCBH3 (=-335 kcal mol-1 ), as observed. 2) Analysis of Fe-L bonding on LS→HS, reveals more ionic (ΔEelstat ) and less covalent (ΔEorb ) character (ΔEelstat :ΔEorb 55:45 LS→64:36 HS), mostly due to a big drop in σ (ΔEorb,σ ↓50 %; -310→-145 kcal mol-1 ), and a drop in π contributions (ΔEorb,π ↓90 %; -30→-3 kcal mol-1 ). 3) Strong correlation of observed T1/2 and ΔEorb,σ+π , for both LS and HS families (R2 =0.99 LS, R2 =0.95 HS), but no correlation of T1/2 and ΔΔEorb,σ+π (LS-HS) (R2 =0.11). Overall, this study has established and validated an EDA-NOCV protocol for M-L bonding analysis of any diamagnetic or paramagnetic, homoleptic or heteroleptic, octahedral transition metal complex. This new and widely applicable EDA-NOCV protocol holds great promise as a predictive tool.
Collapse
Affiliation(s)
- Luca Bondì
- Department of Chemistry andMacDiarmid Institute of Advanced Materials and NanotechnologyUniversity of OtagoPO Box 56Dunedin9054New Zealand
- Department of Chemistry “Ugo Schiff” and INSTM Research UnitUniversity of Florence50019Sesto FiorentinoItaly
| | - Anna L. Garden
- Department of Chemistry andMacDiarmid Institute of Advanced Materials and NanotechnologyUniversity of OtagoPO Box 56Dunedin9054New Zealand
| | - Paul Jerabek
- Centre for Theoretical Chemistry and PhysicsThe New Zealand Institute for Advanced Study andthe Institute for Natural and Mathematical SciencesMassey UniversityAucklandNew Zealand
- Department of NanotechnologyHelmholtz Centre for Materials and Coastal ResearchMax-Planck-Straße 121502GeesthachtGermany
| | - Federico Totti
- Department of Chemistry “Ugo Schiff” and INSTM Research UnitUniversity of Florence50019Sesto FiorentinoItaly
| | - Sally Brooker
- Department of Chemistry andMacDiarmid Institute of Advanced Materials and NanotechnologyUniversity of OtagoPO Box 56Dunedin9054New Zealand
| |
Collapse
|
33
|
Sárosiné Szemes D, Keszthelyi T, Papp M, Varga L, Vankó G. Quantum-chemistry-aided ligand engineering for potential molecular switches: changing barriers to tune excited state lifetimes. Chem Commun (Camb) 2020; 56:11831-11834. [PMID: 33021253 DOI: 10.1039/d0cc04467a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Substitution of terpyridine at the 4' position with electron withdrawing and donating groups is used to tune the quintet lifetime of its iron(ii) complex. DFT calculations suggest that the energy barrier between the quintet and singlet states can be altered significantly upon substitution, inducing a large variation of the lifetime of the photoexcited quintet state. This prediction was experimentally verified by transient optical absorption spectroscopy and good agreement with the trend expected from the calculations was found. This demonstrates that the potential energy landscape can indeed be rationally tailored by relevant modifications based on DFT predictions. This result should pave the way to advancing efficient theory-based ligand engineering of functional molecules to a wide range of applications.
Collapse
|
34
|
Wei J, Wu L, Wang HX, Zhang X, Tse CW, Zhou CY, Huang JS, Che CM. Iron-Catalyzed Highly Enantioselective cis-Dihydroxylation of Trisubstituted Alkenes with Aqueous H 2 O 2. Angew Chem Int Ed Engl 2020; 59:16561-16571. [PMID: 32500643 DOI: 10.1002/anie.202002866] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Indexed: 01/02/2023]
Abstract
Reliable methods for enantioselective cis-dihydroxylation of trisubstituted alkenes are scarce. The iron(II) complex cis-α-[FeII (2-Me2 -BQPN)(OTf)2 ], which bears a tetradentate N4 ligand (Me2 -BQPN=(R,R)-N,N'-dimethyl-N,N'-bis(2-methylquinolin-8-yl)-1,2-diphenylethane-1,2-diamine), was prepared and characterized. With this complex as the catalyst, a broad range of trisubstituted electron-deficient alkenes were efficiently oxidized to chiral cis-diols in yields of up to 98 % and up to 99.9 % ee when using hydrogen peroxide (H2 O2 ) as oxidant under mild conditions. Experimental studies (including 18 O-labeling, ESI-MS, NMR, EPR, and UV/Vis analyses) and DFT calculations were performed to gain mechanistic insight, which suggested possible involvement of a chiral cis-FeV (O)2 reaction intermediate as an active oxidant. This cis-[FeII (chiral N4 ligand)]2+ /H2 O2 method could be a viable green alternative/complement to the existing OsO4 -based methods for asymmetric alkene dihydroxylation reactions.
Collapse
Affiliation(s)
- Jinhu Wei
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Liangliang Wu
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Hai-Xu Wang
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Xiting Zhang
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Chun-Wai Tse
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Cong-Ying Zhou
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Jie-Sheng Huang
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Chi-Ming Che
- State Key Laboratory of Synthetic Chemistry and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, China.,HKU Shenzhen Institute of Research & Innovation, Shenzhen, China
| |
Collapse
|
35
|
Wei J, Wu L, Wang H, Zhang X, Tse C, Zhou C, Huang J, Che C. Iron‐Catalyzed Highly Enantioselective
cis
‐Dihydroxylation of Trisubstituted Alkenes with Aqueous H
2
O
2. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.202002866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Jinhu Wei
- State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong Kong Pokfulam Road Hong Kong China
| | - Liangliang Wu
- State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong Kong Pokfulam Road Hong Kong China
| | - Hai‐Xu Wang
- State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong Kong Pokfulam Road Hong Kong China
| | - Xiting Zhang
- State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong Kong Pokfulam Road Hong Kong China
| | - Chun‐Wai Tse
- State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong Kong Pokfulam Road Hong Kong China
| | - Cong‐Ying Zhou
- State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong Kong Pokfulam Road Hong Kong China
| | - Jie‐Sheng Huang
- State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong Kong Pokfulam Road Hong Kong China
| | - Chi‐Ming Che
- State Key Laboratory of Synthetic Chemistry and Department of ChemistryThe University of Hong Kong Pokfulam Road Hong Kong China
- HKU Shenzhen Institute of Research & Innovation Shenzhen China
| |
Collapse
|
36
|
Vicens L, Olivo G, Costas M. Rational Design of Bioinspired Catalysts for Selective Oxidations. ACS Catal 2020. [DOI: 10.1021/acscatal.0c02073] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Laia Vicens
- Institut de Quı́mica Computacional i Catàlisi (IQCC) and Departament de Quı́mica, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain
| | - Giorgio Olivo
- Institut de Quı́mica Computacional i Catàlisi (IQCC) and Departament de Quı́mica, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain
| | - Miquel Costas
- Institut de Quı́mica Computacional i Catàlisi (IQCC) and Departament de Quı́mica, Universitat de Girona, Campus de Montilivi, 17071 Girona, Spain
| |
Collapse
|
37
|
Thorarinsdottir AE, Bjornsson R, Harris TD. Insensitivity of Magnetic Coupling to Ligand Substitution in a Series of Tetraoxolene Radical-Bridged Fe 2 Complexes. Inorg Chem 2020; 59:4634-4649. [PMID: 32196317 DOI: 10.1021/acs.inorgchem.9b03736] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
The elucidation of magnetostructural correlations between bridging ligand substitution and strength of magnetic coupling is essential to the development of high-temperature molecule-based magnetic materials. Toward this end, we report the series of tetraoxolene-bridged FeII2 complexes [(Me3TPyA)2Fe2(RL)]n+ (Me3TPyA = tris(6-methyl-2-pyridylmethyl)amine; n = 2: OMeLH2 = 3,6-dimethoxy-2,5-dihydroxo-1,4-benzoquinone, ClLH2 = 3,6-dichloro-2,5-dihydroxo-1,4-benzoquinone, Na2[NO2L] = sodium 3,6-dinitro-2,5-dihydroxo-1,4-benzoquinone; n = 4: SMe2L = 3,6-bis(dimethylsulfonium)-2,5-dihydroxo-1,4-benzoquinone diylide) and their one-electron-reduced analogues. Variable-temperature dc magnetic susceptibility data reveal the presence of weak ferromagnetic superexchange between FeII centers in the oxidized species, with exchange constants of J = +1.2(2) (R = OMe, Cl) and +0.3(1) (R = NO2, SMe2) cm-1. In contrast, X-ray diffraction, cyclic voltammetry, and Mössbauer spectroscopy establish a ligand-centered radical in the reduced complexes. Magnetic measurements for the radical-bridged species reveal the presence of strong antiferromagnetic metal-radical coupling, with J = -57(10), -60(7), -58(6), and -65(8) cm-1 for R = OMe, Cl, NO2, and SMe2, respectively. The minimal effects of substituents in the 3- and 6-positions of RLx-• on the magnetic coupling strength is understood through electronic structure calculations, which show negligible spin density on the substituents and associated C atoms of the ring. Finally, the radical-bridged complexes are single-molecule magnets, with relaxation barriers of Ueff = 50(1), 41(1), 38(1), and 33(1) cm-1 for R = OMe, Cl, NO2, and SMe2, respectively. Taken together, these results provide the first examination of how bridging ligand substitution influences magnetic coupling in semiquinoid-bridged compounds, and they establish design criteria for the synthesis of semiquinoid-based molecules and materials.
Collapse
Affiliation(s)
| | - Ragnar Bjornsson
- Department of Inorganic Spectroscopy, Max-Planck-Institut für Chemische Energiekonversion, Mülheim an der Ruhr 45470, Germany
| | - T David Harris
- Department of Chemistry, Northwestern University, Evanston 60208, Illinois, United States.,Department of Chemistry, University of California, Berkeley 94720, California, United States
| |
Collapse
|
38
|
Park H, Lee D. Ligand Taxonomy for Bioinorganic Modeling of Dioxygen-Activating Non-Heme Iron Enzymes. Chemistry 2020; 26:5916-5926. [PMID: 31909506 DOI: 10.1002/chem.201904975] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/04/2020] [Indexed: 12/15/2022]
Abstract
Novel functions emerge from novel structures. To develop efficient catalytic systems for challenging chemical transformations, chemists often seek inspirations from enzymatic catalysis. A large number of iron complexes supported by nitrogen-rich multidentate ligands have thus been developed to mimic oxo-transfer reactivity of dioxygen-activating metalloenzymes. Such efforts have significantly advanced our understanding of the reaction mechanisms by trapping key intermediates and elucidating their geometric and electronic properties. Critical to the success of this biomimetic approach is the design and synthesis of elaborate ligand systems to balance the thermodynamic stability, structural adaptability, and chemical reactivity. In this Concept article, representative design strategies for biomimetic atom-transfer chemistry are discussed from the perspectives of "ligand builders". Emphasis is placed on how the primary coordination sphere is constructed, and how it can be elaborated further by rational design for desired functions.
Collapse
Affiliation(s)
- Hyunchang Park
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| | - Dongwhan Lee
- Department of Chemistry, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Korea
| |
Collapse
|
39
|
Kal S, Xu S, Que L. Bio-inspired Nonheme Iron Oxidation Catalysis: Involvement of Oxoiron(V) Oxidants in Cleaving Strong C-H Bonds. Angew Chem Int Ed Engl 2020; 59:7332-7349. [PMID: 31373120 DOI: 10.1002/anie.201906551] [Citation(s) in RCA: 80] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2019] [Indexed: 11/11/2022]
Abstract
Nonheme iron enzymes generate powerful and versatile oxidants that perform a wide range of oxidation reactions, including the functionalization of inert C-H bonds, which is a major challenge for chemists. The oxidative abilities of these enzymes have inspired bioinorganic chemists to design synthetic models to mimic their ability to perform some of the most difficult oxidation reactions and study the mechanisms of such transformations. Iron-oxygen intermediates like iron(III)-hydroperoxo and high-valent iron-oxo species have been trapped and identified in investigations of these bio-inspired catalytic systems, with the latter proposed to be the active oxidant for most of these systems. In this Review, we highlight the recent spectroscopic and mechanistic advances that have shed light on the various pathways that can be accessed by bio-inspired nonheme iron systems to form the high-valent iron-oxo intermediates.
Collapse
Affiliation(s)
- Subhasree Kal
- Department of Chemistry, University of Minnesota, Twin Cities, 207 Pleasant Street SE, Minneapolis, MN, 55455, USA
| | - Shuangning Xu
- Department of Chemistry, University of Minnesota, Twin Cities, 207 Pleasant Street SE, Minneapolis, MN, 55455, USA
| | - Lawrence Que
- Department of Chemistry, University of Minnesota, Twin Cities, 207 Pleasant Street SE, Minneapolis, MN, 55455, USA
| |
Collapse
|
40
|
Kal S, Xu S, Que L. Bioinspirierte Nicht‐Häm‐Eisenoxidationskatalyse: Beteiligung von Oxoeisen(V)‐Oxidantien an der Spaltung starker C‐H‐Bindungen. Angew Chem Int Ed Engl 2020. [DOI: 10.1002/ange.201906551] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Affiliation(s)
- Subhasree Kal
- Department of Chemistry University of Minnesota, Twin Cities 207 Pleasant Street SE Minneapolis MN 55455 USA
| | - Shuangning Xu
- Department of Chemistry University of Minnesota, Twin Cities 207 Pleasant Street SE Minneapolis MN 55455 USA
| | - Lawrence Que
- Department of Chemistry University of Minnesota, Twin Cities 207 Pleasant Street SE Minneapolis MN 55455 USA
| |
Collapse
|
41
|
Walleck S, Glaser T. A Dinucleating Ligand System with Varying Terminal Donors to Mimic Diiron Active Sites. Isr J Chem 2020. [DOI: 10.1002/ijch.201900097] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Stephan Walleck
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie Universität Bielefeld Universitätsstrasse 25 D-33615 Bielefeld Germany
| | - Thorsten Glaser
- Lehrstuhl für Anorganische Chemie I, Fakultät für Chemie Universität Bielefeld Universitätsstrasse 25 D-33615 Bielefeld Germany
| |
Collapse
|
42
|
Halcrow MA. Manipulating metal spin states for biomimetic, catalytic and molecular materials chemistry. Dalton Trans 2020; 49:15560-15567. [DOI: 10.1039/d0dt01919d] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The relationship between ligand design and spin state in base metal compounds is surveyed. Implications and applications of these principles for light-harvesting dyes, catalysis and materials chemistry are summarised.
Collapse
|
43
|
Liu Y, You T, Wang HX, Tang Z, Zhou CY, Che CM. Iron- and cobalt-catalyzed C(sp3)–H bond functionalization reactions and their application in organic synthesis. Chem Soc Rev 2020; 49:5310-5358. [DOI: 10.1039/d0cs00340a] [Citation(s) in RCA: 62] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This review highlights the developments in iron and cobalt catalyzed C(sp3)–H bond functionalization reactions with emphasis on their applications in organic synthesis, i.e. natural products and pharmaceuticals synthesis and/or modification.
Collapse
Affiliation(s)
- Yungen Liu
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- P. R. China
| | - Tingjie You
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Hai-Xu Wang
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Zhou Tang
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Cong-Ying Zhou
- Department of Chemistry
- State Key Laboratory of Synthetic Chemistry
- The University of Hong Kong
- Hong Kong
- P. R. China
| | - Chi-Ming Che
- Department of Chemistry
- Southern University of Science and Technology
- Shenzhen
- P. R. China
- Department of Chemistry
| |
Collapse
|
44
|
Senthil Kumar K, Vela S, Heinrich B, Suryadevara N, Karmazin L, Bailly C, Ruben M. Bi-stable spin-crossover in charge-neutral [Fe(R-ptp) 2] (ptp = 2-(1H-pyrazol-1-yl)-6-(1H-tetrazol-5-yl)pyridine) complexes. Dalton Trans 2019; 49:1022-1031. [PMID: 31859300 DOI: 10.1039/c9dt04411f] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Bi-stable charge-neutral iron(ii) spin-crossover (SCO) complexes are a class of switchable molecular materials proposed for molecule-based switching and memory applications. In this study, we report on the SCO behavior of a series of iron(ii) complexes composed of rationally designed 2-(1H-pyrazol-1-yl)-6-(1H-tetrazol-5-yl)pyridine (ptp) ligands. The powder forms of [Fe2+(R-ptp-)2]0 complexes tethered with less-bulky substituents-R = H (1), R = CH2OH (2), and R = COOCH3 (3; previously reported)-at the 4-position of the pyridine ring of the ptp skeleton showed abrupt and hysteretic SCO at or above room temperature (RT), whereas complex 5 featuring a bulky pyrene substituent showed incomplete and gradual SCO behavior. The role of intermolecular interactions, lattice solvent, and electronic nature of the chemical substituents (R) in tuning the SCO of the complexes is elucidated.
Collapse
Affiliation(s)
- Kuppusamy Senthil Kumar
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg, 23, rue du Loess, BP 43, 67034 Strasbourg Cedex 2, France.
| | - Sergi Vela
- Laboratoire de Chimie Quantique, Institut de Chimie, UMR 7177 CNRS-Université de Strasbourg, 4 rue Blaise Pascal, 67081 Strasbourg, France.
| | - Benoît Heinrich
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg, 23, rue du Loess, BP 43, 67034 Strasbourg Cedex 2, France.
| | - Nithin Suryadevara
- Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
| | - Lydia Karmazin
- Service de Radiocristallographie, Fédération de Chimie Le Bel, FR2010 CNRS-Université de Strasbourg, 1 rue Blaise Pascal, BP 296/R8, 67008 Strasbourg Cedex, France
| | - Corinne Bailly
- Service de Radiocristallographie, Fédération de Chimie Le Bel, FR2010 CNRS-Université de Strasbourg, 1 rue Blaise Pascal, BP 296/R8, 67008 Strasbourg Cedex, France
| | - Mario Ruben
- Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg, 23, rue du Loess, BP 43, 67034 Strasbourg Cedex 2, France. and Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen, Germany.
| |
Collapse
|
45
|
Ozumerzifon TJ, Higgins RF, Joyce JP, Kolanowski JL, Rappé AK, Shores MP. Evidence for Reagent-Induced Spin-State Switching in Tripodal Fe(II) Iminopyridine Complexes. Inorg Chem 2019; 58:7785-7793. [DOI: 10.1021/acs.inorgchem.9b00340] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tarik J. Ozumerzifon
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Robert F. Higgins
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Justin P. Joyce
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Jacek L. Kolanowski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Noskowskiego 12/14, 61-704 Poznań, Poland
| | - Anthony K. Rappé
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| | - Matthew P. Shores
- Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, United States
| |
Collapse
|
46
|
Abstract
We report herein on five new Fe(II) complexes of general formula [Fe(L)2(NCCH3)2](BF4)2•xCH3CN (L = substituted 2-pyridylimine-based ligands). The influence of proximally located electron withdrawing groups (e.g., NO2, CN, CF3, Cl, Br) bound to coordinated pyridylimine ligands has been studied for the effect on spin crossover in their Fe(II) complexes. Variable-temperature UV-visible spectroscopic studies performed on complexes with more strongly electronegative ligand substituents revealed spin crossover (SCO) in the solution, and thermodynamic parameters associated with the spin crossover were estimated.
Collapse
|
47
|
Mukherjee G, Alili A, Barman P, Kumar D, Sastri CV, de Visser SP. Interplay Between Steric and Electronic Effects: A Joint Spectroscopy and Computational Study of Nonheme Iron(IV)-Oxo Complexes. Chemistry 2019; 25:5086-5098. [PMID: 30720909 DOI: 10.1002/chem.201806430] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Indexed: 01/05/2023]
Abstract
Iron is an essential element in nonheme enzymes that plays a crucial role in many vital oxidative transformations and metabolic reactions in the human body. Many of those reactions are regio- and stereospecific and it is believed that the selectivity is guided by second-coordination sphere effects in the protein. Here, results are shown of a few engineered biomimetic ligand frameworks based on the N4Py (N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) scaffold and the second-coordination sphere effects are studied. For the first time, selective substitutions in the ligand framework have been shown to tune the catalytic properties of the iron(IV)-oxo complexes by regulating the steric and electronic factors. In particular, a better positioning of the oxidant and substrate in the rate-determining transition state lowers the reaction barriers. Therefore, an optimum balance between steric and electronic factors mediates the ideal positioning of oxidant and substrate in the rate-determining transition state that affects the reactivity of high-valent reaction intermediates.
Collapse
Affiliation(s)
- Gourab Mukherjee
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Aligulu Alili
- The Manchester Institute of Biotechnology and School of Chemical, Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Prasenjit Barman
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Devesh Kumar
- Department of Applied Physics, Babasaheb Bhimrao Ambedkar University, School for Physical Sciences, Vidya Vihar, Rae Bareilly Road, Lucknow, 226025, UP, India
| | - Chivukula V Sastri
- Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Sam P de Visser
- The Manchester Institute of Biotechnology and School of Chemical, Engineering and Analytical Science, The University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| |
Collapse
|
48
|
McPherson JN, Hogue RW, Akogun FS, Bondì L, Luis ET, Price JR, Garden AL, Brooker S, Colbran SB. Predictable Substituent Control of Co III/II Redox Potential and Spin Crossover in Bis(dipyridylpyrrolide)cobalt Complexes. Inorg Chem 2019; 58:2218-2228. [PMID: 30672281 DOI: 10.1021/acs.inorgchem.8b03457] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A family of five easily prepared tridentate monoanionic 2,5-dipyridyl-3-(R1)-4-(R2)-pyrrolide anions (dppR1,R2)-, varying in the nature of the R1 and R2 substituents [R1, R2 = CN, Ph; CO2Et, CO2Et; CO2Me, 4-Py; CO2Me, Me; Me, Me], has been used to generate the analogous family of neutral [CoII(dppR1,R2)2] complexes, two of which are structurally characterized at both 100 and 298 K. Both the oxidation and spin states of these complexes can be switched in response to appropriate external stimuli. All complexes, except [CoII(dppMe,Me)2], exhibit gradual spin crossover (SCO) in the solid state, and SCO activity is observed for three complexes in CDCl3 solution. The cobalt(II) centers in the low spin (LS) complexes are Jahn-Teller tetragonally compressed along the pyrrolide-Co-pyrrolide axis. The complexes in their high spin (HS) states are more distorted than in the LS states, as is also usually the case for SCO active iron(II) complexes. The reversible CoIII/II redox potentials are predictably tuned by choice of substituents R1 and R2, from -0.95 (Me,Me) to -0.45 (CN,Ph) V vs Fc+/Fc, with a linear correlation observed between E1/2(CoIII/II) and the Swain-Lupton parameters of the pyrrolide substituents.
Collapse
Affiliation(s)
- James N McPherson
- School of Chemistry , The University of New South Wales , Kensington , NSW 2052 , Australia
| | - Ross W Hogue
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology , University of Otago , P.O. Box 56, Dunedin 9054 , New Zealand
| | - Folaranmi Sunday Akogun
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology , University of Otago , P.O. Box 56, Dunedin 9054 , New Zealand
| | - Luca Bondì
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology , University of Otago , P.O. Box 56, Dunedin 9054 , New Zealand
| | - Ena T Luis
- School of Chemistry , The University of New South Wales , Kensington , NSW 2052 , Australia
| | - Jason R Price
- ANSTO, Australian Synchrotron , Clayton , VIC Australia
| | - Anna L Garden
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology , University of Otago , P.O. Box 56, Dunedin 9054 , New Zealand
| | - Sally Brooker
- Department of Chemistry and MacDiarmid Institute for Advanced Materials and Nanotechnology , University of Otago , P.O. Box 56, Dunedin 9054 , New Zealand
| | - Stephen B Colbran
- School of Chemistry , The University of New South Wales , Kensington , NSW 2052 , Australia
| |
Collapse
|
49
|
Glaser T. A dinucleating ligand system with varying terminal donor functions but without bridging donor functions: Design, synthesis, and applications for diiron complexes. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2018.09.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
50
|
Křižan M, Vinklárek J, Erben M, Růžičková Z, Honzíček J. Iron(II) complex with modified bispidine ligand: Synthesis and catalytic alkyd drying. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2018.11.035] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|