1
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Biswas M, Dey S, Dhara S, Panda S, Lahiri GK. Metal-ligand synergy driven functionalisation of alkylene linked bis(aldimine) on a diruthenium(II) platform. Cyclisation versus oxygenation. Dalton Trans 2024; 53:2167-2180. [PMID: 38192265 DOI: 10.1039/d3dt03730d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2024]
Abstract
This article addresses the impact of metal-ligand redox cooperativity on the functionalisation of coordinated ligands. It demonstrates the structure-reactivity correlation of bis(aldimine) derived bis-bidentate L (Py-CHN-(CH2)n-NCH-Py, with n = 2 (L1), 3 (L2), 4 (L3)) as a function of the conformation (syn/anti) of its alkylene linker as well as the overall structural form (cis/trans) of (acac)2RuII(μ-L)RuII(acac)2 complex moieties (1-5) possessing an electron-rich acetylacetonate (acac) co-ligand. A systematic variation of the bridging alkylene unit of L in RuII/RuII-derived 1-5 led to the following reactivity/redox events, which were validated through structural, spectroscopic, electrochemical and theoretical evaluations: (i) Cyclisation of the ethylene linked (syn conformation) bis-aldimine unit of L1 via C-C coupling yielded pyrazine bridged (acac)2RuII(μ-L1')RuII(acac)2, 1a, while the corresponding anti-form (ethylene linker) of the metal-bound L1 in 2 ((acac)2RuII(μ-L1)RuII(acac)2) led to oxygenation at the ligand backbone (bis-aldimine (L) → bis(carboxamido) (L'')) via O2 activation to generate RuIIIRuIII-derived (acac)2RuIII(μ-L1''2-)RuIII(acac)2 (2a). (ii) Consequently, propylene and butylene linked L2 and L3 bridged between two {Ru(acac)2} units in 3 and 4/5 underwent oxygenation of L to L'' to yield diruthenium(III) complexes 3a and 4a/5a, respectively. (iii) In contrast, analogous L bridged oxidised [(acac)2RuIII(μ-L)RuIII(acac)2](ClO4)2 ([2](ClO4)2-[5](ClO4)2) and [{(PPh3)2(CO)(H)RuII}2(μ-L)](ClO4)2 ([6](ClO4)2-[8](ClO4)2) involving electron poor co-ligands failed to undergo the oxygenation of L irrespective of its n value, reemphasising the effective role of redox interplay between RuII and L particularly in the presence of an electron-rich acac co-ligand in the functionalisation of the latter in 1a-5a.
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Affiliation(s)
- Mitrali Biswas
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Sanchaita Dey
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Suman Dhara
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Sanjib Panda
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
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2
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Himmelbauer D, Müller F, Schweinzer C, Casas F, Pribanic B, Le Corre G, Thöny D, Trincado M, Grützmacher H. Selective dehydrogenation of ammonia borane to polycondensated BN rings catalysed by ruthenium olefin complexes. Chem Commun (Camb) 2024; 60:885-888. [PMID: 38165285 PMCID: PMC10795514 DOI: 10.1039/d3cc05709g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 12/14/2023] [Indexed: 01/03/2024]
Abstract
Dehydrogenation of ammonia borane to well-defined products is an important but challenging reaction. A dinuclear ruthenium complex with a Ru-Ru bond bearing a diazadiene (dad) unit and olefins as non-innocent ligands catalyzes the highly selective formation of conjugated polycondensed borazine oligomers (BxNxHy), predominantly B21N21H18, the BN analogue of superbenzene.
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Affiliation(s)
- Daniel Himmelbauer
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
- Institute of Applied Synthetic Chemistry, TU Wien, Getreidemarkt 9/163Vienna A-1060Austria
| | - Fabian Müller
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
| | - Clara Schweinzer
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
| | - Fernando Casas
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
| | - Bruno Pribanic
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
| | - Grégoire Le Corre
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
| | - Debora Thöny
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
| | - Monica Trincado
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied Biosciences, ETH Zurich Vladimir-Prelog-Weg 1Zurich CH-8049Switzerlandtrincado@inorg,chem.ethz.ch
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3
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Mukherjee A, Datta S, Richmond MG, Bhattacharya S. Ruthenium complexes of 1,4-diazabutadiene ligands with a cis-RuCl 2 moiety for catalytic acceptorless dehydrogenation of alcohols: DFT evidence of chemically non-innocent ligand participation. RSC Adv 2023; 13:25660-25672. [PMID: 37649575 PMCID: PMC10463240 DOI: 10.1039/d3ra04750d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Accepted: 08/07/2023] [Indexed: 09/01/2023] Open
Abstract
The acceptorless dehydrogenative coupling (ADC) of primary alcohols to esters by diazabutadiene-coordinated ruthenium compounds is reported. Treatment of cis-Ru(dmso)4Cl2 in acetone at 56 °C with different 1,4-diazabutadienes [p-XC6H4N[double bond, length as m-dash]C(H)(H)C[double bond, length as m-dash]NC6H4X-p; X = H, CH3, OCH3, and Cl; abbreviated as DAB-X], gives trans-Ru[κ2-N,N-DAB-X]2Cl2 as the kinetic product of substitution. Heating these products in o-xylene at 144 °C gives the thermodynamically favored cis-Ru[κ2-N,N-DAB-X]2Cl2 isomers. Electronic structure calculations confirm the greater stability of the cis diastereomer. The molecular structures for each pair of geometric isomers have been determined by X-ray diffraction analyses. Cyclic voltammetry experiments on the complexes show an oxidative response and a reductive response within 0.50 to 0.93 V and -0.76 to -1.24 V vs. SCE respectively. The cis-Ru[κ2-N,N-DAB-X]2Cl2 complexes function as catalyst precursors for the acceptorless dehydrogenative coupling of primary alcohols to H2 and homo- and cross-coupled esters. When 1,4-butanediol and 1,5-pentanediol are employed as substrates, lactones and hydroxyaldehydes are produced as the major dehydrogenation products, while secondary alcohols afforded ketones in excellent yields. The mechanism for the dehydrogenation of benzyl alcohol to benzyl benzoate and H2 using cis-Ru[κ2-N,N-DAB-H]2Cl2 (cis-1) as a catalyst precursor was investigated by DFT calculations. The data support a catalytic cycle that involves the four-coordinate species Ru[κ2-N,N-DAB-H][κ1-N-DAB-H](κ1-OCH2Ph) whose protonated κ1-diazabutadiene moiety functions as a chemically non-innocent ligand that facilitates a β-hydrogen elimination from the κ1-O-benzoxide ligand to give the corresponding hydride HRu[κ2-N,N-DAB-H][κ1-N-DAB-H](κ2-O,C-benzaldehyde). H2 production follows a Noyori-type elimination to give (H2)Ru[κ2-N,N-DAB-H][κ1-N-DAB-H](κ1-O-benzaldehyde) as an intermediate in the catalytic cycle.
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Affiliation(s)
- Aparajita Mukherjee
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University Kolkata 700 032 India
| | - Sayanti Datta
- Department of Chemistry, Brainware University Kolkata 700 125 India
| | | | - Samaresh Bhattacharya
- Department of Chemistry, Inorganic Chemistry Section, Jadavpur University Kolkata 700 032 India
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4
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Vitillo JG, Cramer CJ, Gagliardi L. Multireference Methods are Realistic and Useful Tools for Modeling Catalysis. Isr J Chem 2022. [DOI: 10.1002/ijch.202100136] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Jenny G. Vitillo
- Department of Science and High Technology and INSTM Università degli Studi dell'Insubria Via Valleggio 9 I-22100 Como Italy
| | - Christopher J. Cramer
- Underwriters Laboratories Inc. 333 Pfingsten Road Northbrook Illinois 60602 United States
| | - Laura Gagliardi
- Department of Chemistry Pritzker School of Molecular Engineering James Franck Institute University of Chicago Chicago Illinois 60637 United States
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5
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de Zwart FJ, Sinha V, Trincado M, Grützmacher H, de Bruin B. Computational mechanistic studies of ruthenium catalysed methanol dehydrogenation. Dalton Trans 2022; 51:3019-3026. [PMID: 35079760 PMCID: PMC8862544 DOI: 10.1039/d1dt04168a] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Homogeneous ruthenium catalysed methanol dehydrogenation could become a key reaction for hydrogen production in liquid fuel cells. In order to improve existing catalytic systems, mechanistic insight is paramount in directing future studies. Herein, we describe what computational mechanistic research has taught us so far about ruthenium catalysed dehydrogenation reactions. In general, two mechanistic pathways can be operative in these reactions: a metal-centered or a metal-ligand cooperative (Noyori-Morris type) minimum energy reaction pathway (MERP). Discerning between these mechanisms on the basis of computational studies has proven to be highly input dependent, and to circumvent pitfalls it is important to consider several factors, such as solvent effects, metal-ligand cooperativity, alternative geometries, and complex electronic structures of metal centres. This Frontiers article summarizes the reported computational research performed on ruthenium catalyzed dehydrogenation reactions performed in the past decade, and serves as a guide for future research.
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Affiliation(s)
- Felix J de Zwart
- Van 't Hoff Institute for Molecular Sciences (HIMS), Science Park 904, 1098 XH Amsterdam, The Netherlands.
| | - Vivek Sinha
- Inorganic Systems Engineering, Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft 2629 HZ, The Netherlands.
| | - Monica Trincado
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland
| | - Hansjörg Grützmacher
- Laboratory of Inorganic Chemistry, Department of Chemistry and Applied Biosciences, ETH Zurich, Vladimir-Prelog-Weg 1-5/10, 8093 Zurich, Switzerland
| | - Bas de Bruin
- Van 't Hoff Institute for Molecular Sciences (HIMS), Science Park 904, 1098 XH Amsterdam, The Netherlands.
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6
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van Leest N, de Zwart FJ, Zhou M, de Bruin B. Controlling Radical-Type Single-Electron Elementary Steps in Catalysis with Redox-Active Ligands and Substrates. JACS AU 2021; 1:1101-1115. [PMID: 34467352 PMCID: PMC8385710 DOI: 10.1021/jacsau.1c00224] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Indexed: 06/13/2023]
Abstract
Advances in (spectroscopic) characterization of the unusual electronic structures of open-shell cobalt complexes bearing redox-active ligands, combined with detailed mapping of their reactivity, have uncovered several new catalytic radical-type protocols that make efficient use of the synergistic properties of redox-active ligands, redox-active substrates, and the metal to which they coordinate. In this perspective, we discuss the tools available to study, induce, and control catalytic radical-type reactions with redox-active ligands and/or substrates, contemplating recent developments in the field, including some noteworthy tools, methods, and reactions developed in our own group. The main topics covered are (i) tools to characterize redox-active ligands; (ii) novel synthetic applications of catalytic reactions that make use of redox-active carbene and nitrene substrates at open-shell cobalt-porphyrins; (iii) development of catalytic reactions that take advantage of purely ligand- and substrate-based redox processes, coupled to cobalt-centered spin-changing events in a synergistic manner; and (iv) utilization of redox-active ligands to influence the spin state of the metal. Redox-active ligands have emerged as useful tools to generate and control reactive metal-coordinated radicals, which give access to new synthetic methodologies and intricate (electronic) structures, some of which are yet to be exposed.
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Affiliation(s)
- Nicolaas
P. van Leest
- Homogeneous, Supramolecular and Bio-Inspired
Catalysis Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Felix J. de Zwart
- Homogeneous, Supramolecular and Bio-Inspired
Catalysis Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Minghui Zhou
- Homogeneous, Supramolecular and Bio-Inspired
Catalysis Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
| | - Bas de Bruin
- Homogeneous, Supramolecular and Bio-Inspired
Catalysis Group, van ’t Hoff Institute for Molecular Sciences
(HIMS), University of Amsterdam, Science Park 904, 1098 XH Amsterdam, The Netherlands
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7
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de Zwart FJ, Reus B, Laporte AAH, Sinha V, de Bruin B. Metrical Oxidation States of 1,4-Diazadiene-Derived Ligands. Inorg Chem 2021; 60:3274-3281. [PMID: 33587616 PMCID: PMC8023656 DOI: 10.1021/acs.inorgchem.0c03685] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
![]()
The
conventional method of assigning formal oxidation states (FOSs)
to metals and ligands is an important tool for understanding and predicting
the chemical reactivity, in particular, in catalysis research. For
complexes containing redox-noninnocent ligands, the oxidation state
of the ligand can be ambiguous (i.e., their spectroscopic oxidation
state can differ from the FOS) and thus frustrates the assignment
of the oxidation state of the metal. A quantitative correlation between
the empirical metric data of redox-active
ligands and their oxidation states using a metrical oxidation state
(MOS) model has been developed for catecholate- and amidophenoxide-derived
ligands by Brown. In the present work, we present a MOS model for
1,4-diazabutadiene (DADn) ligands. This
model is based on a similar approach as reported by Brown, correlating
the intra-ligand bond lengths of the DADn moiety in a quantitative manner with the MOS using geometrical information
from X-ray structures in the Cambridge Crystallographic Data Center
(CCDC) database. However, an accurate determination of the MOS of
these ligands turned out to be dependent on the coordination mode
of the DAD2– moiety, which can adopt both a planar
κ2-N2-geometry and a
η4-N2C2 π-coordination mode in (transition) metal complexes
in its doubly reduced, dianionic enediamide oxidation state. A reliable
MOS model was developed taking the intrinsic differences in intra-ligand
bond distances between these coordination modes of the DAD2– ligand into account. Three different models were defined and tested
using different geometric parameters (C=C → M distance,
M–N–C angle, and M–N–C–C torsion
angle) to describe the C=C backbone coordination with the metal
in the η4-N2-C2 π-coordination mode of the DAD2– ligand. Statistical analysis revealed that the C=C →
M distance best describes the η4-N2-C2 coordination mode using
a cutoff value of 2.46 Å for π-coordination. The developed
MOS model was used to validate the oxidation state assignment of elements
not contained within the training set (Sr, Yb, and Ho), thus demonstrating
the applicability of the MOS model to a wide range of complexes. Chromium
complexes with complex electronic structures were also shown to be
accurately described by MOS analysis. Furthermore, it is shown that
a combination of MOS analysis and FOD calculations provides an inexpensive
method to gain insight into the electronic structure of singlet spin
state (S = 0) [M(trop2dad)] transition-metal complexes
showing (potential) singlet biradical character. Assigning oxidation states to metals
and ligands is an important
tool for understanding and predicting the chemical reactivity. For
complexes containing redox-noninnocent ligands, the oxidation state
of the ligand can be ambiguous. We present a metrical oxidation state
model for 1,4-diazabutadiene ligands, correlating the intra-ligand
bond lengths with the oxidation state using information from X-ray
structures. This model accounts for the difference in bond length
distances between the different coordination modes of the fully reduced
ligand.
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Affiliation(s)
- Felix J de Zwart
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Bente Reus
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Annechien A H Laporte
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Vivek Sinha
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
| | - Bas de Bruin
- Van 't Hoff Institute for Molecular Sciences, University of Amsterdam, 1098 XH Amsterdam, The Netherlands
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8
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Bera SK, Lahiri GK. Unprecedented metal-metal bonded {Ru 4(μ 3-O) 2} butterfly core in oxido-carboxylato bridged mixed valence cluster-structural elucidation and electronic forms in accessible redox states. Dalton Trans 2020; 49:13573-13581. [PMID: 32970073 DOI: 10.1039/d0dt02741c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unprecedented metal-metal bonded oxido-carboxylato bridged mixed valence tetraruthenium cluster [(acac)6Ru(μ3-O)2(μ-CH3COO)3] 1 (S = 1/2) (acac = acetylacetonate) with {Ru4(μ3-O)2} "butterfly" core has been achieved via the reaction of Ru(acac)2(CH3CN)2 with excess CH3COONa (Ru : CH3COONa = 1 : 15) in refluxing EtOH-H2O (5 : 1). Structural analysis of 1 ascertained a unique Ru-Ru bonded (Ru2-Ru3: 2.5187(6) Å (DFT: 2.560 Å)) {Ru2(Ru-Ru)(μ3-O)2} butterfly core, unlike the reported other Fe4 or Mn4 derived "butterfly" core. The connectivity of Ru4(μ3-O)2 core in 1 with three Ru2(μ-CH3COO)3 and two each Ru-(acac)2/Ru-acac units resulted in interconnected four RuO6 octahedral entities. The doubly bridged μ3-O2- ions of the nearly planar central metal-metal bonded Ru2O2 core (Ru2-Ru3, "body" or "hinge") linked to the remaining two "wing-tip" Ru atoms (Ru1 and Ru4). Complex 1 with a S = 1/2 spin state displayed paramagnetically shifted 1H NMR over a wide chemical shift range in CDCl3 (δ, 13 to -30 ppm) and a metal based anisotropic EPR (g1 = 2.17, g2 = 2.01, g3 = 1.86; Δg = g1-g3 = 0.31 and 〈g〉 = [1/3(g12 + g22 + g32]1/2 = 2.01) at 100 K in CH3CN-toluene. The metal based one-electron reversible oxidation at 0.49 V and reduction at 0.485 V versus SCE of 1 led to the EPR inactive (even at 4 K) spin-coupled RuIIIRuIIIRuIVRuIV (S = 0) and RuIIIRuIIIRuIIIRuIII (S = 0) electronic configurations for 1+ and 1-, respectively. Mixed valence 1 and 1+ exhibited low-energy near-infrared (NIR) absorption bands at 1350 nm and 1156 nm, respectively, in CH3CN. A combined experimental (UV-vis-NIR and EPR spectroelectrochemistry) and theoretical (DFT) analysis indicated a delocalised mixed valence form of 1 ({Ru2(Ru-Ru)(μ3-O)2}).
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Affiliation(s)
- Sudip Kumar Bera
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai-400076, India.
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9
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Bloch J, Kradolfer S, L. Gianetti T, Ostendorf D, Dey S, Mougel V, Grützmacher H. Synthesis and Characterization of Ion Pairs between Alkaline Metal Ions and Anionic Anti-Aromatic and Aromatic Hydrocarbons with π-Conjugated Central Seven- and Eight-Membered Rings. Molecules 2020; 25:molecules25204742. [PMID: 33076581 PMCID: PMC7594067 DOI: 10.3390/molecules25204742] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/02/2020] [Accepted: 10/04/2020] [Indexed: 11/29/2022] Open
Abstract
The synthesis, isolation and full characterization of ion pairs between alkaline metal ions (Li+, Na+, K+) and mono-anions and dianions obtained from 5H-dibenzo[a,d]cycloheptenyl (C15H11 = trop) is reported. According to Nuclear Magnetic Resonance (NMR) spectroscopy, single crystal X-ray analysis and Density Functional Theory (DFT) calculations, the trop‒ and trop2−• anions show anti-aromatic properties which are dependent on the counter cation M+ and solvent molecules serving as co-ligands. For comparison, the disodium and dipotassium salt of the dianion of dibenzo[a,e]cyclooctatetraene (C16H12 = dbcot) were prepared, which show classical aromatic character. A d8-Rh(I) complex of trop− was prepared and the structure shows a distortion of the C15H11 ligand into a conjugated 10π -benzo pentadienide unit—to which the Rh(I) center is coordinated—and an aromatic 6π electron benzo group which is non-coordinated. Electron transfer reactions between neutral and anionic trop and dbcot species show that the anti-aromatic compounds obtained from trop are significantly stronger reductants.
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Affiliation(s)
- Jan Bloch
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Stefan Kradolfer
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Thomas L. Gianetti
- Department of Chemistry & Biochemistry, 1306 E. University Blvd., Tucson, AZ 85719, USA;
| | - Detlev Ostendorf
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Subal Dey
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Victor Mougel
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied Biosciences, ETH Zürich, 8093 Zürich, Switzerland; (J.B.); (S.K.); (D.O.); (S.D.); (V.M.)
- Correspondence:
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10
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Martin J, Langer J, Wiesinger M, Elsen H, Harder S. Dibenzotropylidene Substituted Ligands for Early Main Group Metal‐Alkene Bonding. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000524] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Johannes Martin
- Inorganic and Organometallic Chemistry Friedrich‐Alexander‐Universität Erlangen‐Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Jens Langer
- Inorganic and Organometallic Chemistry Friedrich‐Alexander‐Universität Erlangen‐Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Michael Wiesinger
- Inorganic and Organometallic Chemistry Friedrich‐Alexander‐Universität Erlangen‐Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Holger Elsen
- Inorganic and Organometallic Chemistry Friedrich‐Alexander‐Universität Erlangen‐Nürnberg Egerlandstraße 1 91058 Erlangen Germany
| | - Sjoerd Harder
- Inorganic and Organometallic Chemistry Friedrich‐Alexander‐Universität Erlangen‐Nürnberg Egerlandstraße 1 91058 Erlangen Germany
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11
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Alcântara AFP, Fontana LA, Almeida MP, Rigolin VH, Ribeiro MA, Barros WP, Megiatto JD. Control over the Redox Cooperative Mechanism of Radical Carbene Transfer Reactions for the Efficient Active‐Metal‐Template Synthesis of [2]Rotaxanes. Chemistry 2020; 26:7808-7822. [DOI: 10.1002/chem.201905602] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Indexed: 02/01/2023]
Affiliation(s)
- Arthur F. P. Alcântara
- Institute of ChemistryUniversity of Campinas (UNICAMP) PO Box 6154 13083-970 Campinas Brazil
- Instituto Federal do Sertão Pernambucano Estrada do Tamboril 56200-000 Ouricuri Brazil
| | - Liniquer A. Fontana
- Institute of ChemistryUniversity of Campinas (UNICAMP) PO Box 6154 13083-970 Campinas Brazil
| | - Marlon P. Almeida
- Institute of ChemistryUniversity of Campinas (UNICAMP) PO Box 6154 13083-970 Campinas Brazil
| | - Vitor H. Rigolin
- Institute of ChemistryUniversity of Campinas (UNICAMP) PO Box 6154 13083-970 Campinas Brazil
| | - Marcos A. Ribeiro
- Departamento de QuímicaUniversidade Federal do Espírito Santo Av. Fernando Ferrari, 514 29075-910 Vitória Brazil
| | - Wdeson P. Barros
- Institute of ChemistryUniversity of Campinas (UNICAMP) PO Box 6154 13083-970 Campinas Brazil
| | - Jackson D. Megiatto
- Institute of ChemistryUniversity of Campinas (UNICAMP) PO Box 6154 13083-970 Campinas Brazil
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12
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Panda S, Goel P, Lahiri GK. Non-Spectator Feature of α-Diimine Mimicked Di/tetrahydro-bisisoquinoline and Biimidazopyridine on {Ru(acac)2
} Platform. Eur J Inorg Chem 2020. [DOI: 10.1002/ejic.202000230] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Affiliation(s)
- Sanjib Panda
- Department of Chemistry; Indian Institute of Technology Bombay; 400076 Mumbai Powai India
| | - Puneet Goel
- Department of Chemistry; Indian Institute of Technology Bombay; 400076 Mumbai Powai India
| | - Goutam Kumar Lahiri
- Department of Chemistry; Indian Institute of Technology Bombay; 400076 Mumbai Powai India
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13
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Affiliation(s)
- Wolfgang Kaim
- Institut für Anorganische Chemie Universität Stuttgart Pfaffenwaldring 55 70550 Stuttgart Germany
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14
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Herndon JW. The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2018. Coord Chem Rev 2019. [DOI: 10.1016/j.ccr.2019.213051] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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15
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van der Vlugt JI. Radical-Type Reactivity and Catalysis by Single-Electron Transfer to or from Redox-Active Ligands. Chemistry 2019; 25:2651-2662. [PMID: 30084211 PMCID: PMC6471147 DOI: 10.1002/chem.201802606] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Indexed: 12/12/2022]
Abstract
Controlled ligand-based redox-activity and chemical non-innocence are rapidly gaining importance for selective (catalytic) processes. This Concept aims to provide an overview of the progress regarding ligand-to-substrate single-electron transfer as a relatively new mode of operation to exploit ligand-centered reactivity and catalysis based thereon.
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Affiliation(s)
- Jarl Ivar van der Vlugt
- Bio-Inspired Homogeneous and Supramolecular Catalysis Groupvan ‘t Hoff Institute for Molecular SciencesUniversity of AmsterdamScience Park 9041098 XHAmsterdamNetherlands
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16
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Azek E, Khalifa M, Bartholoméüs J, Ernzerhof M, Lebel H. Rhodium(ii)-catalyzed C-H aminations using N-mesyloxycarbamates: reaction pathway and by-product formation. Chem Sci 2019; 10:718-729. [PMID: 30746107 PMCID: PMC6340404 DOI: 10.1039/c8sc03153c] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Accepted: 10/19/2018] [Indexed: 01/06/2023] Open
Abstract
N-Mesyloxycarbamates are practical nitrene precursors that undergo C-H amination reactions in the presence of rhodium dimer catalysts. Under these conditions, both oxazolidinones and chiral amines have been prepared in a highly efficient manner. Given the elevated reactivity of the intermediates involved in the catalytic cycle, mechanistic details have remained hypothetical, relying on indirect experiments. Herein a density functional theory (DFT) study is presented to validate the catalytic cycle of the rhodium-catalyzed C-H amination with N-mesyloxycarbamates. A concerted pathway involving Rh-nitrene species that undergoes C-H insertion is found to be favored over a stepwise C-N bond formation manifold. Density functional calculations and kinetic studies suggest that the rate-limiting step is the C-H insertion process rather than the formation of Rh-nitrene species. In addition, these studies provide mechanistic details about competitive by-product formation, resulting from an intermolecular reaction between the Rh-nitrene species and the N-mesyloxycarbamate anion.
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Affiliation(s)
- Emna Azek
- Département de Chimie , Université de Montréal , C.P. 6128, Succursale Centre-ville, Montréal , Québec , Canada H3C3J7 .
| | - Maroua Khalifa
- Département de Chimie , Université de Montréal , C.P. 6128, Succursale Centre-ville, Montréal , Québec , Canada H3C3J7 .
| | - Johan Bartholoméüs
- Département de Chimie , Université de Montréal , C.P. 6128, Succursale Centre-ville, Montréal , Québec , Canada H3C3J7 .
| | - Matthias Ernzerhof
- Département de Chimie , Université de Montréal , C.P. 6128, Succursale Centre-ville, Montréal , Québec , Canada H3C3J7 .
| | - Hélène Lebel
- Département de Chimie , Université de Montréal , C.P. 6128, Succursale Centre-ville, Montréal , Québec , Canada H3C3J7 .
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17
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Li H, Gonçalves TP, Lupp D, Huang KW. PN3(P)-Pincer Complexes: Cooperative Catalysis and Beyond. ACS Catal 2019. [DOI: 10.1021/acscatal.8b04495] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Huaifeng Li
- KAUST Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Théo P. Gonçalves
- KAUST Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Daniel Lupp
- KAUST Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
| | - Kuo-Wei Huang
- KAUST Catalysis Center and Division of Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia
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18
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Sinha V, Trincado M, Grützmacher H, de Bruin B. DFT Provides Insight into the Additive-Free Conversion of Aqueous Methanol to Dihydrogen Catalyzed by [Ru(trop 2dad)]: Importance of the (Electronic) Flexibility of the Diazadiene Moiety. J Am Chem Soc 2018; 140:13103-13114. [PMID: 30215248 PMCID: PMC6209174 DOI: 10.1021/jacs.8b09011] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
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The
mechanism for complete dehydrogenation of aqueous methanol to CO2 and three equivalents of H2 catalyzed by [Ru(trop2dad)] was investigated with DFT (trop2dad = 1,4-bis(5H-dibenzo[a,d]cyclohepten-5-yl)-1,4-diazabuta-1,3-diene).
To date, this is the only catalyst that promotes the acceptorless
dehydrogenation of aqueous methanol in homogeneous phase under mild
conditions without the addition of an additive (base, acid, or a secondary
catalyst). A detailed understanding of the mechanism of this transformation
may therefore be of significant importance for the conversion of liquid
organic fuels. Previous computational studies using simplified models
of the catalyst suggested entirely ligand-centered reaction pathways
with rather high-energy barriers for complete dehydrogenation of aqueous
methanol. These are, however, not consistent with the experimental
data. In the present paper, we reveal a different reaction mechanism
for aqueous methanol dehydrogenation that involves metal–ligand
cooperativity involving the diazadiene (dad) ligand and has substantially
lower barriers, in good agreement with the experimental data. The
dad moiety of the ligand actively participates in the alcohol activation
mechanism. In the first step of the reaction, the dad ligand rearranges
from a σ- to a π-bound coordination mode. This adjusts
the electronic structure of both the metal and the ligand, leading
to an enhanced Brønsted basicity of the nitrogen centers and
higher Lewis acidity of the ruthenium center. As a result, concerted
proton-hydride transfer to/from metal-hydride and N-protonated dad-ligand
moieties becomes possible, leading to low-barrier metal–ligand
cooperative elementary steps for alcohol activation and H2 elimination.
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Affiliation(s)
- Vivek Sinha
- Homogeneous, Supramolecular and Bio-inspired Catalysis Group (HomKat), van 't Hoff Institute for Molecular Sciences (HIMS) , Universiteit van Amsterdam , Amsterdam 1012 WX , The Netherlands
| | - Monica Trincado
- Laboratorium für Anorganische Chemie , ETH , Zürich 8092 , Switzerland
| | | | - Bas de Bruin
- Homogeneous, Supramolecular and Bio-inspired Catalysis Group (HomKat), van 't Hoff Institute for Molecular Sciences (HIMS) , Universiteit van Amsterdam , Amsterdam 1012 WX , The Netherlands
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19
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Chatterjee M, Mondal S, Ghosh P, Kaim W, Lahiri GK. Mononuclear and Dinuclear Ruthenium Complexes of cis- and trans-Thioindigo: Geometrical and Electronic Structure Analyses. Inorg Chem 2018; 57:12187-12194. [DOI: 10.1021/acs.inorgchem.8b01829] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Madhumita Chatterjee
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Sudipta Mondal
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Prabir Ghosh
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
| | - Wolfgang Kaim
- Institut für Anorganische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70550 Stuttgart, Germany
| | - Goutam Kumar Lahiri
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India
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20
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Sinha V, Pribanic B, de Bruin B, Trincado M, Grützmacher H. Ligand- and Metal-Based Reactivity of a Neutral Ruthenium Diolefin Diazadiene Complex: The Innocent, the Guilty and the Suspicious. Chemistry 2018; 24:5513-5521. [PMID: 29341297 PMCID: PMC5947567 DOI: 10.1002/chem.201705957] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Indexed: 11/17/2022]
Abstract
Coordination of the diazadiene diolefin ligand (trop2 dad) to ruthenium leads to various complexes of composition [Ru(trop2 dad)(L)]. DFT studies indicate that the closed-shell singlet (CSS), open-shell singlet (OSS), and triplet electronic structures of this species are close in energy, with the OSS spin configuration being the lowest in energy for all tested functionals. Singlet-state CASSCF calculations revealed a significant multireference character for these complexes. The closed-shell singlet wavefunction dominates, but these complexes have a significant (≈8-16 %) open-shell singlet [d7 -RuI (L)(trop2 dad.- )] contribution mixed into the ground state. In agreement with their ambivalent electronic structure, these complexes reveal both metal- and ligand-centered reactivity. Most notable are the reactions with AdN3 , diazomethane, and a phosphaalkyne leading to scission of the C-C bond of the diazadiene (dad) moiety of the trop2 dad ligand, resulting in net (formal) nitrene, carbene, or P≡C insertion in the dad C-C bond, respectively. Supporting DFT studies revealed that several of the ligand-based reactions proceed via low-barrier radical-type pathways, involving the dad.- ligand radical character of the OSS or triplet species.
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Affiliation(s)
- Vivek Sinha
- Supramolecular and Homogeneous Catalysis GroupVan 't Hoff Institute for Molecular Sciences (HIMS)University of AmsterdamScience park 9041098XHAmsterdamThe Netherlands
| | - Bruno Pribanic
- Department of Chemistry and Applied Biosciences ETH ZürichLaboratory of Inorganic ChemistryVladimir-Prelog-Weg 1ZürichCH-8093Switzerland
| | - Bas de Bruin
- Supramolecular and Homogeneous Catalysis GroupVan 't Hoff Institute for Molecular Sciences (HIMS)University of AmsterdamScience park 9041098XHAmsterdamThe Netherlands
| | - Monica Trincado
- Department of Chemistry and Applied Biosciences ETH ZürichLaboratory of Inorganic ChemistryVladimir-Prelog-Weg 1ZürichCH-8093Switzerland
| | - Hansjörg Grützmacher
- Department of Chemistry and Applied Biosciences ETH ZürichLaboratory of Inorganic ChemistryVladimir-Prelog-Weg 1ZürichCH-8093Switzerland
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