1
|
Queen JD, Anderson-Sanchez LM, Stennett CR, Rajabi A, Ziller JW, Furche F, Evans WJ. Synthesis of Crystallographically Characterizable Bis(cyclopentadienyl) Sc(II) Complexes: (C 5H 2tBu 3) 2Sc and {[C 5H 3(SiMe 3) 2] 2ScI} 1. J Am Chem Soc 2024; 146:3279-3292. [PMID: 38264991 DOI: 10.1021/jacs.3c11922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2024]
Abstract
The synthesis of previously unknown bis(cyclopentadienyl) complexes of the first transition metal, i.e., Sc(II) scandocene complexes, has been investigated using C5H2(tBu)3 (Cpttt), C5Me5 (Cp*), and C5H3(SiMe3)2 (Cp″) ligands. Cpttt2ScI, 1, formed from ScI3 and KCpttt, can be reduced with potassium graphite (KC8) in hexanes to generate dark-red crystals of the first crystallographically characterizable bis(cyclopentadienyl) scandium(II) complex, Cpttt2Sc, 2. Complex 2 has a 170.6° (ring centroid)-Sc-(ring centroid) angle and exhibits an eight-line EPR spectrum characteristic of Sc(II) with Aiso = 82.6 MHz (29.6 G). It sublimes at 200 °C at 10-4 Torr and has a melting point of 268-271 °C. Reductions of Cp*2ScI and Cp″2ScI under analogous conditions in hexanes did not provide new Sc(II) complexes, and reduction of Cp*2ScI in benzene formed the Sc(III) phenyl complex, Cp*2Sc(C6H5), 3, by C-H bond activation. However, in Et2O and toluene, reduction of Cp*2ScI at -78 °C gives a dark-red solution, 4, which displays an eight-line EPR pattern like that of 1, but it did not provide thermally stable crystals. Reduction of Cp″2ScI, in THF or Et2O at -35 °C in the presence of 2.2.2-cryptand, yields the green Sc(II) metallocene iodide complex, [K(crypt)][Cp″2ScI], 5, which was identified by X-ray crystallography and EPR spectroscopy and is thermally unstable. The analogous reaction of Cp*2ScI with KC8 and 18-crown-6 in Et2O gave the ligand redistribution product, [Cp*2Sc(18-crown-6-κ2O,O')][Cp*2ScI2], 6, as the only crystalline product. Density functional theory calculations on the electronic structure of these compounds are reported in addition to a steric analysis using the Guzei method.
Collapse
Affiliation(s)
- Joshua D Queen
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | | | - Cary R Stennett
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Ahmadreza Rajabi
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Joseph W Ziller
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Filipp Furche
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - William J Evans
- Department of Chemistry, University of California, Irvine, California 92697-2025, United States
| |
Collapse
|
2
|
Vollgraff T, Doppiu A, Sundermeyer J. Dihydroguaiazulenide Complexes and Catalysts of Group 8-12 Transition Metals: Ligands from Renewable Feedstock Replace, even Outmatch Petrochemical Based Cyclopentadienyl Chemistry. Chemistry 2024; 30:e202302994. [PMID: 37955549 DOI: 10.1002/chem.202302994] [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: 09/14/2023] [Revised: 11/09/2023] [Accepted: 11/09/2023] [Indexed: 11/14/2023]
Abstract
We present an in-depth study of the sterically demanding Cp-synthon (8-H-GuaH)Li isolated from natural product guaiazulene (Gua) as a ligand transfer reagent towards late transition metal complex precursors. The synthesis and full characterization of selected, essentially unexplored homo- and heteroleptic 8-H-guaiazulenide complexes of iron, ruthenium, cobalt, rhodium, platinum, copper and zinc are discussed in detail. In order to demonstrate their potential in catalytic applications, [(GuaH)PtMe3 ] was selected. The latter proved an even higher catalytic activity in light induced olefin hydrosilylation at catalyst loads as low as 5 ppm than classical [CpPtMe3 ] in a typical test reaction of silicone elastomer fabrication. Our results demonstrate that traditional petrochemical based Cp metal chemistry and catalysis can be replaced, sometimes even outmatched by superior catalysts based on cheap building blocks from renewable feedstock.
Collapse
Affiliation(s)
- Tobias Vollgraff
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany
| | - Angelino Doppiu
- Umicore AG&Co. KG, PMC R&D, Rodenbacher Chaussee 4, 63457, Hanau-Wolfgang, Germany
| | - Jörg Sundermeyer
- Fachbereich Chemie and Wissenschaftliches Zentrum für Materialwissenschaften (WZMW), Philipps-Universität Marburg, Hans-Meerwein-Straße 4, 35043, Marburg, Germany
| |
Collapse
|
3
|
Rong J, Wu Y, Ji X, Zhao T, Yin B, Rao Y, Zhou M, Osuka A, Xu L, Song J. Porphyrinatonickel(II)-Cyclopentene and Porphyrinatonickel(II)-Cyclopentadiene Hybrids: Zirconacyclopentadiene-Mediated Syntheses, Structures, and Mechanistic Study. Org Lett 2022; 24:6128-6132. [PMID: 35960173 DOI: 10.1021/acs.orglett.2c02120] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The reaction of meso-formyl Ni(II) porphyrin 1 with zirconacyclopentadiene 2 in the presence of AlCl3 afforded four products 3, 4, 5, and 6 with a total yield of over 85%. The structures of these compounds are well-characterized by 1H NMR an d13C NMR spectroscopy, HRMS, and X-ray single-crystal diffraction. The mechanism is proposed mainly on the basis of isotopic labeling experiments, which showed that a Friedel-Crafts-type reaction and β-H shift may be critical during the formation of 5 and 6.
Collapse
Affiliation(s)
- Jian Rong
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Yidan Wu
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Xiaoheng Ji
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Tingting Zhao
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Bangshao Yin
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Yutao Rao
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Mingbo Zhou
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Atsuhiro Osuka
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Ling Xu
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| | - Jianxin Song
- Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research, Ministry of Education, Key Laboratory of the Assembly and Application of Organic Functional Molecules of Hunan Province, College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha, Hunan 410081, China
| |
Collapse
|
4
|
Smytschkow I, Gidt W, Sun Y, Langer J, Böttcher T, Kubíčková L, Kaman O, Sitzmann H. Chromium(II) Alkylcyclopentadienyl Complexes with Carbon or Hydride Donor Ligands. Organometallics 2021. [DOI: 10.1021/acs.organomet.1c00159] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Igor Smytschkow
- FB Chemie der TUK, Erwin-Schrödinger-Str. 54, 67663 Kaiserslautern, Germany
| | - Wjatscheslaw Gidt
- FB Chemie der TUK, Erwin-Schrödinger-Str. 54, 67663 Kaiserslautern, Germany
| | - Yu Sun
- FB Chemie der TUK, Erwin-Schrödinger-Str. 54, 67663 Kaiserslautern, Germany
| | - Jens Langer
- Department Chemie und Pharmazie, FAU Erlangen-Nürnberg, Egerlandstr. 1, 91058 Erlangen, Germany
| | - Tobias Böttcher
- Institut für Anorganische und Analytische Chemie, Albertstr. 21, 79104 Freiburg, Germany
| | - Lenka Kubíčková
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10/112, 162 00 Praha 6, Czech Republic
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00 Praha 8, Czech Republic
| | - Ondřej Kaman
- Institute of Physics of the Czech Academy of Sciences, Cukrovarnická 10/112, 162 00 Praha 6, Czech Republic
| | - Helmut Sitzmann
- FB Chemie der TUK, Erwin-Schrödinger-Str. 54, 67663 Kaiserslautern, Germany
| |
Collapse
|
5
|
Peters M, Baabe D, Maekawa M, Bockfeld D, Zaretzke MK, Tamm M, Walter MD. Pogo-Stick Iron and Cobalt Complexes: Synthesis, Structures, and Magnetic Properties. Inorg Chem 2019; 58:16475-16486. [PMID: 31769666 DOI: 10.1021/acs.inorgchem.9b02411] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis, structures, and magnetic properties of monomeric half-sandwich iron and cobalt imidazolin-2-iminato complexes have been comprehensively investigated. Salt metathesis reactions of [Cp'M(μ-I)]2 (1-M, M = Fe, Co; Cp' = η5-1,2,4-tri-tert-butylcyclopentadienyl) with [ImDippNLi]2 (ImDippN = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-iminato) furnishes the terminal half-sandwich compounds [Cp'M(NImDipp)] (2-M, M = Fe, Co), which can be regarded as models for elusive half-sandwich iron and cobalt imido complexes. X-ray diffraction analysis confirmed the structure motif of a one-legged piano stool. Complex 2-Co can also be prepared by an acid-base reaction between [Cp'Co{N(SiMe3)2}] (3-Co) and ImDippNH. The electronic and magnetic properties of 2-M and 3-Co were probed by 57Fe Mössbauer spectroscopy (M = Fe), X-band EPR spectroscopy (M = Co), and solid-state magnetic susceptibility measurements. In particular, the central metal atom adopts a high-spin (S = 2) state in 2-Fe, while the cobalt complex 2-Co represents a rare example of a Co(II) species with a coordination number different from six displaying a low-spin to high-spin spin-crossover (SCO) behavior. The experimental observations are complemented by DFT calculations.
Collapse
Affiliation(s)
- Marius Peters
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
| | - Dirk Baabe
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
| | - Miyuki Maekawa
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
| | - Dirk Bockfeld
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
| | - Marc-Kevin Zaretzke
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
| | - Matthias Tamm
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
| | - Marc D Walter
- Institut für Anorganische und Analytische Chemie , Technische Universität Braunschweig , Hagenring 30 , 38106 Braunschweig , Germany
| |
Collapse
|
6
|
|
7
|
Song H, Ye K, Geng P, Han X, Liao R, Tung CH, Wang W. Activation of Epoxides by a Cooperative Iron–Thiolate Catalyst: Intermediacy of Ferrous Alkoxides in Catalytic Hydroboration. ACS Catal 2017. [DOI: 10.1021/acscatal.7b02527] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Heng Song
- School
of Chemistry and Chemical Engineering, Shandong University, 27 South Shanda Road, Jinan, 250100, China
| | - Ke Ye
- School
of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
| | - Peiyu Geng
- School
of Chemistry and Chemical Engineering, Shandong University, 27 South Shanda Road, Jinan, 250100, China
| | - Xiao Han
- School
of Chemistry and Chemical Engineering, Shandong University, 27 South Shanda Road, Jinan, 250100, China
| | - Rongzhen Liao
- School
of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, 1037 Luoyu Road, Wuhan, 430074, China
| | - Chen-Ho Tung
- School
of Chemistry and Chemical Engineering, Shandong University, 27 South Shanda Road, Jinan, 250100, China
| | - Wenguang Wang
- School
of Chemistry and Chemical Engineering, Shandong University, 27 South Shanda Road, Jinan, 250100, China
| |
Collapse
|
8
|
Veinot AJ, Todd ADK, Masuda JD. A Bulky m
-Terphenyl Cyclopentadienyl Ligand and Its Alkali-Metal Complexes. Angew Chem Int Ed Engl 2017. [DOI: 10.1002/ange.201706398] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Alex J. Veinot
- Atlantic Centre for Green Chemistry and Department of Chemistry; Saint Mary's University; 923 Robie Street Halifax Nova Scotia B3H 3C3 Canada
| | - Angela D. K. Todd
- Atlantic Centre for Green Chemistry and Department of Chemistry; Saint Mary's University; 923 Robie Street Halifax Nova Scotia B3H 3C3 Canada
| | - Jason D. Masuda
- Atlantic Centre for Green Chemistry and Department of Chemistry; Saint Mary's University; 923 Robie Street Halifax Nova Scotia B3H 3C3 Canada
| |
Collapse
|
9
|
Groß OA, Lauk S, Müller C, Gidt W, Sun Y, Demeshko S, Meyer F, Sitzmann H. Iron(II) High‐Spin and Low‐Spin Complexes from Pentaisopropylcyclopentadienyliron(II) Bis(trimethylsilyl)amide. Eur J Inorg Chem 2017. [DOI: 10.1002/ejic.201700236] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Oliver A. Groß
- FB Chemie TU Kaiserslautern Erwin‐Schrödinger‐Strasse 54 67663 Kaiserslautern Germany
| | - Sergej Lauk
- FB Chemie TU Kaiserslautern Erwin‐Schrödinger‐Strasse 54 67663 Kaiserslautern Germany
| | - Carsten Müller
- FB Chemie TU Kaiserslautern Erwin‐Schrödinger‐Strasse 54 67663 Kaiserslautern Germany
| | - Wjatscheslaw Gidt
- FB Chemie TU Kaiserslautern Erwin‐Schrödinger‐Strasse 54 67663 Kaiserslautern Germany
| | - Yu Sun
- FB Chemie TU Kaiserslautern Erwin‐Schrödinger‐Strasse 54 67663 Kaiserslautern Germany
| | - 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
| | - Helmut Sitzmann
- FB Chemie TU Kaiserslautern Erwin‐Schrödinger‐Strasse 54 67663 Kaiserslautern Germany
| |
Collapse
|
10
|
Veinot AJ, Todd ADK, Masuda JD. A Bulky m
-Terphenyl Cyclopentadienyl Ligand and Its Alkali-Metal Complexes. Angew Chem Int Ed Engl 2017; 56:11615-11619. [DOI: 10.1002/anie.201706398] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Indexed: 01/23/2023]
Affiliation(s)
- Alex J. Veinot
- Atlantic Centre for Green Chemistry and Department of Chemistry; Saint Mary's University; 923 Robie Street Halifax Nova Scotia B3H 3C3 Canada
| | - Angela D. K. Todd
- Atlantic Centre for Green Chemistry and Department of Chemistry; Saint Mary's University; 923 Robie Street Halifax Nova Scotia B3H 3C3 Canada
| | - Jason D. Masuda
- Atlantic Centre for Green Chemistry and Department of Chemistry; Saint Mary's University; 923 Robie Street Halifax Nova Scotia B3H 3C3 Canada
| |
Collapse
|
11
|
Thakur A, Bheemireddy V, Bhatta SR. Access to an abnormal position of N-heterocyclic carbene-Mn(II)-complex by pyrazolyl phosphane with a labile P N bond. J Organomet Chem 2017. [DOI: 10.1016/j.jorganchem.2017.01.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
12
|
Zendaoui SM, Saillard JY, Zouchoune B. Ten-Electron Donor Indenyl Anion in Binuclear Transition-Metal Sandwich Complexes: Electronic Structure and Bonding Analysis. ChemistrySelect 2016. [DOI: 10.1002/slct.201600309] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Saber-Mustapha Zendaoui
- Laboratoire de Chimie Appliquée et Technologie des Matériaux; Université Larbi Ben M'Hidi - Oum El Bouaghi; 04000 Oum El Bouaghi Algeria
- Unité de Recherche de Chimie de l'Environnement et Moléculaire Structurale; Université de Constantine; 25000 Constantine Algeria
| | - Jean-Yves Saillard
- Institut des Sciences Chimiques de Rennes; UMR-CNRS 6226; Université de Rennes 1; 35042 Rennes-Cedex France
| | - Bachir Zouchoune
- Laboratoire de Chimie Appliquée et Technologie des Matériaux; Université Larbi Ben M'Hidi - Oum El Bouaghi; 04000 Oum El Bouaghi Algeria
- Unité de Recherche de Chimie de l'Environnement et Moléculaire Structurale; Université de Constantine; 25000 Constantine Algeria
| |
Collapse
|
13
|
Saiad A, Zouchoune B. Electronic structure and bonding analysis of transition metal sandwich and half-sandwich complexes of the triphenylene ligand. CAN J CHEM 2015. [DOI: 10.1139/cjc-2015-0104] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Full geometry optimization using the BP86 and B3LYP methods has been carried out for all of the low-energy isomers of half-sandwich L3M(Tphn) (Tphn = triphenylene, M = Ti–Ni, and L3 = (CO)3, Cp–) and sandwich M(Tphn)2 (Tphn = triphenylene and M = Ti, Cr, Fe, Ni) structures. Depending on the electron richness of the molecule and the nature of the metal, a complete rationalization of the bonding in triphenylene complexes has been provided. The triphenylene adopts various hapticities from η2 to η6, some of them involving full or partial coordination of the C6 ring and shown to be quite flexible with respect to the ground spin state. The triphenylene behavior remains dependent on the electron-withdrawing and electron-donor properties of the (CO)3M and CpM fragments, respectively. For the sandwich complexes, both triphenylene ligands prefer to behave differently depending on the coordination mode to satisfy the metal electron demand.
Collapse
Affiliation(s)
- Amira Saiad
- Laboratoire de Chimie appliquée et Technologie des Matériaux, Université Larbi Ben, M’Hidi, Oum el Bouaghi, (04000) Oum el Bouaghi, Algeria
| | - Bachir Zouchoune
- Laboratoire de Chimie appliquée et Technologie des Matériaux, Université Larbi Ben, M’Hidi, Oum el Bouaghi, (04000) Oum el Bouaghi, Algeria
- Unité de Recherche de Chimie de l’Environnement et Moléculaire Structurale, Université Constantine (ex Mentouri Constantine), Algeria
| |
Collapse
|
14
|
Al-Afyouni MH, Krishnan VM, Arman HD, Tonzetich ZJ. Synthesis and Reactivity of Manganese(II) Complexes Containing N-Heterocyclic Carbene Ligands. Organometallics 2015. [DOI: 10.1021/acs.organomet.5b00684] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Malik H. Al-Afyouni
- Department
of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
- Department
of Chemistry, University of Rochester, Rochester, New York 14627, United States
| | - V. Mahesh Krishnan
- Department
of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Hadi D. Arman
- Department
of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| | - Zachary J. Tonzetich
- Department
of Chemistry, University of Texas at San Antonio, San Antonio, Texas 78249, United States
| |
Collapse
|
15
|
Coordination diversity of the phenazine ligand in binuclear transition metal sandwich complexes: Theoretical investigation. J Organomet Chem 2014. [DOI: 10.1016/j.jorganchem.2014.07.025] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
16
|
Weber K, Erdem ÖF, Bill E, Weyhermüller T, Lubitz W. Modeling the Active Site of [NiFe] Hydrogenases and the [NiFeu] Subsite of the C-Cluster of Carbon Monoxide Dehydrogenases: Low-Spin Iron(II) Versus High-Spin Iron(II). Inorg Chem 2014; 53:6329-37. [DOI: 10.1021/ic500910z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Katharina Weber
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Özlen F. Erdem
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Eckhard Bill
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Thomas Weyhermüller
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| | - Wolfgang Lubitz
- Max Planck Institute for Chemical Energy Conversion, Stiftstrasse 34-36, D-45470 Mülheim an der Ruhr, Germany
| |
Collapse
|
17
|
Kreye M, Daniliuc CG, Freytag M, Jones PG, Walter MD. Coordination chemistry of sterically encumbered pyrrolyl ligands to chromium(ii): mono(pyrrolyl)chromium and diazachromocene formation. Dalton Trans 2014; 43:9052-60. [PMID: 24781869 DOI: 10.1039/c4dt00533c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Markus Kreye
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Hagenring 30, 38106 Braunschweig, Germany.
| | | | | | | | | |
Collapse
|
18
|
Schär M, Saurenz D, Zimmer F, Schädlich I, Wolmershäuser G, Demeshko S, Meyer F, Sitzmann H, Heigl OM, Köhler FH. Paramagnetic 18-Valence-Electron Alkylcyclopentadienylnickel(II) Bromide Dimers. Organometallics 2013. [DOI: 10.1021/om400606t] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Marion Schär
- Fachbereich Chemie, TU Kaiserslautern, Erwin-Schrödinger-Strasse
54, 67663 Kaiserslautern, Germany
| | - Dirk Saurenz
- Fachbereich Chemie, TU Kaiserslautern, Erwin-Schrödinger-Strasse
54, 67663 Kaiserslautern, Germany
| | - Frank Zimmer
- Fachbereich Chemie, TU Kaiserslautern, Erwin-Schrödinger-Strasse
54, 67663 Kaiserslautern, Germany
| | - Ina Schädlich
- Fachbereich Chemie, TU Kaiserslautern, Erwin-Schrödinger-Strasse
54, 67663 Kaiserslautern, Germany
| | - Gotthelf Wolmershäuser
- Fachbereich Chemie, TU Kaiserslautern, Erwin-Schrödinger-Strasse
54, 67663 Kaiserslautern, Germany
| | - Serhiy Demeshko
- Institut für
Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Franc Meyer
- Institut für
Anorganische Chemie, Georg-August-Universität, Tammannstrasse 4, 37077 Göttingen, Germany
| | - Helmut Sitzmann
- Fachbereich Chemie, TU Kaiserslautern, Erwin-Schrödinger-Strasse
54, 67663 Kaiserslautern, Germany
| | - Oliver M. Heigl
- Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| | - Frank H. Köhler
- Department Chemie, Technische Universität München, Lichtenbergstrasse 4, 85747 Garching, Germany
| |
Collapse
|
19
|
Wang C, Zhang X, Bai Y, Gao F, Li Q. High-spin binuclear cyclopentadienyliron chlorides: a density functional theory study. J Mol Model 2013; 19:3077-86. [PMID: 23595311 DOI: 10.1007/s00894-013-1826-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2012] [Accepted: 03/18/2013] [Indexed: 11/26/2022]
Abstract
Theoretical studies on the cyclopentadienyliron chlorides Cp2Fe2Cl(n) (n = 6 - 1) with iron in the formal oxidation states from +1 to +4 indicate that all the high-spin species are predicted to be the lowest energy structures and they are paramagnetic complexes with magnetic moments between 2.8μ(B) and 5.9μ(B). The mixed oxidation state derivatives with odd number of chloride atoms have larger magnetic moments than other species. In addition to Cp2Fe2Cl, which has the largest magnetic moment, these high-spin species have terminal Cp rings and bridging Cl atoms up to a maximum of two bridges. The Cp2Fe2Cl4, Cp2Fe2Cl3 and Cp2Fe2Cl2 derivatives are predicted to be thermodynamically stable molecules with respect to exothermic reactions for the loss of one Cl atom from Cp2Fe2Cl n . Moreover, the lowest energy Cp2Fe2Cl(n) (n = 3, 4) derivatives can be derived by the oxidative addition reactions of Cp2Fe2Cl(n-2) + Cl2 → Cp2Fe2Cl(n).
Collapse
Affiliation(s)
- Congzhi Wang
- Key Laboratory of Cluster Science, Ministry of Education of China, School of Chemistry, Beijing Institute of Technology, Beijing 100081, People's Republic of China
| | | | | | | | | |
Collapse
|
20
|
Kreye M, Glöckner A, Daniliuc CG, Freytag M, Jones PG, Tamm M, Walter MD. Sterically encumbered pyrrolyl ligands and their incorporation into the cycloheptatrienyl zirconium coordination sphere. Dalton Trans 2013. [DOI: 10.1039/c2dt32433d] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
21
|
Chekkal F, Zendaoui SM, Zouchoune B, Saillard JY. Structural and spin diversity of M(indenyl)2 transition-metal complexes: a DFT investigation. NEW J CHEM 2013. [DOI: 10.1039/c3nj00196b] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
22
|
Wang JW, Tian LJ, Ma ZH, Guo KM, Han ZG, Zheng XZ, Lin J. Crystal structures of dimolybdenum carbonyl complexes containing the cyclopentadienyl-thienyl ligand. J STRUCT CHEM+ 2012. [DOI: 10.1134/s0022476612040233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
23
|
Maekawa M, Daniliuc CG, Freytag M, Jones PG, Walter MD. Complexes of manganese, iron and cobalt with sterically demanding indenyl ligands. Dalton Trans 2012; 41:10317-27. [PMID: 22772481 DOI: 10.1039/c2dt31136d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Miyuki Maekawa
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | | | | | | | | |
Collapse
|
24
|
Glöckner A, Bauer H, Maekawa M, Bannenberg T, Daniliuc CG, Jones PG, Sun Y, Sitzmann H, Tamm M, Walter MD. How big is a Cp? Cycloheptatrienyl zirconium complexes with bulky cyclopentadienyl and indenyl ligands. Dalton Trans 2012; 41:6614-24. [DOI: 10.1039/c2dt12132h] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
25
|
Maekawa M, Römelt M, Daniliuc CG, Jones PG, White PS, Neese F, Walter MD. Reactivity studies on [Cp′MnX(thf)]2: manganese amide and polyhydride synthesis. Chem Sci 2012. [DOI: 10.1039/c2sc20737k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
26
|
Weismann D, Saurenz D, Boese R, Bläser D, Wolmershäuser G, Sun Y, Sitzmann H. Cyclopentadiene Alkylation and Nickel Complexes with Tri-, Tetra-, or Pentaisopropylcyclopentadienide or an Even Bulkier Lithium Alkylcyclopentadienide. Organometallics 2011. [DOI: 10.1021/om200372j] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Daniel Weismann
- Fachbereich Chemie der TU Kaiserslautern, Erwin-Schrödinger-Straße
54, 67663 Kaiserslautern, Germany
| | - Dirk Saurenz
- Fachbereich Chemie der TU Kaiserslautern, Erwin-Schrödinger-Straße
54, 67663 Kaiserslautern, Germany
| | - Roland Boese
- Fachbereich Chemie der TU Kaiserslautern, Erwin-Schrödinger-Straße
54, 67663 Kaiserslautern, Germany
| | - Dieter Bläser
- Fachbereich Chemie der TU Kaiserslautern, Erwin-Schrödinger-Straße
54, 67663 Kaiserslautern, Germany
| | - Gotthelf Wolmershäuser
- Fachbereich Chemie der TU Kaiserslautern, Erwin-Schrödinger-Straße
54, 67663 Kaiserslautern, Germany
| | - Yu Sun
- Fachbereich Chemie der TU Kaiserslautern, Erwin-Schrödinger-Straße
54, 67663 Kaiserslautern, Germany
| | - Helmut Sitzmann
- Fachbereich Chemie der TU Kaiserslautern, Erwin-Schrödinger-Straße
54, 67663 Kaiserslautern, Germany
| |
Collapse
|
27
|
Halcrow MA. Structure:function relationships in molecular spin-crossover complexes. Chem Soc Rev 2011; 40:4119-42. [PMID: 21483934 DOI: 10.1039/c1cs15046d] [Citation(s) in RCA: 642] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Spin-crossover compounds are becoming increasingly popular for device and sensor applications, and in soft materials, that make use of their switchable colour, paramagnetism and conductivity. The de novo design of new solid spin-crossover compounds with pre-defined switching properties is desirable for application purposes. This challenging problem of crystal engineering requires an understanding of how the temperature and cooperativity of a spin-transition are influenced by the structure of the bulk material. Towards that end, this critical review presents a survey of molecular spin-crossover compounds with good availability of crystallographic data. A picture is emerging that changes in molecular shape between the high- and low-spin states, and the ability of a lattice to accommodate such changes, can play an important role in determining the existence and the cooperativity of a thermal spin-transition in the solid state (198 references).
Collapse
Affiliation(s)
- Malcolm A Halcrow
- School of Chemistry, University of Leeds, Woodhouse Lane, Leeds, UK LS2 9JT. m.a.halcrow@ leeds.ac.uk
| |
Collapse
|
28
|
Walter MD, Grunenberg J, White PS. Reactivity studies on [Cp′FeI]2: From iron hydrides to P4-activation. Chem Sci 2011. [DOI: 10.1039/c1sc00413a] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
|
29
|
Crisp JA, Meier RM, Overby JS, Hanusa TP, Rheingold AL, Brennessel WW. Indenyl Complexes of Manganese(II). Conformational Flexibility of the Manganese(II)−(RnC9H7−n) Bond. Organometallics 2010. [DOI: 10.1021/om100162j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jeffrey A. Crisp
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Ryan M. Meier
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Jason S. Overby
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Timothy P. Hanusa
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | | | | |
Collapse
|
30
|
Ma ZH, Zhao MX, Li F, Wang H, Zheng XZ, Lin J. Synthesis and structures of substituted tetramethylcyclopentadienyl dinuclear metal carbonyl compounds. TRANSIT METAL CHEM 2010. [DOI: 10.1007/s11243-010-9339-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
31
|
Layfield RA. Manganese(ii): the black sheep of the organometallic family. Chem Soc Rev 2008; 37:1098-107. [DOI: 10.1039/b708850g] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
32
|
Synthesis and structure of halogen derivatives of 9-dimethylsulfonium-7,8-dicarba-nido-undecaborane [9-Me2S-7,8-C2B9H11]. J Organomet Chem 2007. [DOI: 10.1016/j.jorganchem.2007.07.036] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
33
|
Lin J, Gao P, Li B, Xu S, Song H, Wang B. Synthesis and structures of aryl-substituted tetramethylcyclopentadienyl dinuclear metal carbonyl complexes. Inorganica Chim Acta 2006. [DOI: 10.1016/j.ica.2006.05.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
34
|
Layfield RA, Bühl M, Rawson JM. Structure, Bonding, and Paramagnetism in the Manganese(II) Tris-Allyl Anions [Mn{ηx-(C3H3R2)3}]- (R = H, SiMe3; x = 1 or 3): Insight from Theory. Organometallics 2006. [DOI: 10.1021/om060295a] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Richard A. Layfield
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom, and Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Michael Bühl
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom, and Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| | - Jeremy M. Rawson
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, United Kingdom, and Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D-45470 Mülheim an der Ruhr, Germany
| |
Collapse
|
35
|
Akbayeva DN. Cu(I) and Ru(II) complexes with elemental phosphorus as ligand: Synthesis and properties. RUSS J COORD CHEM+ 2006. [DOI: 10.1134/s1070328406050046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
36
|
Determination of chromium valence over the range Cr(0)–Cr(VI) by electron energy loss spectroscopy. Ultramicroscopy 2006. [DOI: 10.1016/j.ultramic.2006.02.005] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
37
|
Alvarez CS, Bashall A, McInnes EJL, Layfield RA, Mole RA, McPartlin M, Rawson JM, Wood PT, Wright DS. Structural and Magnetic Studies of the Tris(cyclopentadienyl)manganese(II) “Paddle-Wheel” Anions [Cp3−n(MeCp)nMn]− (n=0–3, MeCp=C5H4CH3, Cp=C5H5). Chemistry 2006; 12:3053-60. [PMID: 16453354 DOI: 10.1002/chem.200501214] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The ion-contact complexes [{(eta(5)-Cp)(2)Mn(eta(2):eta(5)-Cp)K}(3)]x0.5 THF (1x0.5 THF) and [{(eta(2)-Cp)(2)(eta(2);eta(5)-MeCp)MnK(thf)}]x2 THF (2x2 THF) and ion-separated complexes [Mg(thf)(6)][(eta(2)-Cp)(3)Mn](2) (3), [Mg(thf)(6)][(eta(2)-Cp)(eta(2)-MeCp)(2)Mn)](2)x0.5 THF (4x0.5 THF), [Mg(thf)(6)][(eta(2)-MeCp)(3)Mn)](2)x0.5 THF (5x0.5 THF) and [Li([12]crown-4)](5)[(eta-Cp)(3)Mn](5) (6) (Cp=C(5)H(5), CpMe=C(5)H(4)CH(3)), have been prepared and structurally characterised. The effects of varying the Cp and CpMe ligands in complexes 1-5 have been probed by variable-temperature magnetic susceptibility measurements and EPR spectroscopic studies.
Collapse
Affiliation(s)
- Carmen Soria Alvarez
- University of Cambridge, Department of Chemistry, Lensfield Road, Cambridge, CB2 1EW, UK
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Doherty JC, Ballem KHD, Patrick BO, Smith KM. Synthesis and Reactivity of Chromium Cyclopentadienyl β-Diketiminato Compounds. Organometallics 2004. [DOI: 10.1021/om034065x] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jayne C. Doherty
- Departments of Chemistry, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, Canada C1A 4P3, and University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Katherine H. D. Ballem
- Departments of Chemistry, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, Canada C1A 4P3, and University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Brian O. Patrick
- Departments of Chemistry, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, Canada C1A 4P3, and University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| | - Kevin M. Smith
- Departments of Chemistry, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, Canada C1A 4P3, and University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z1
| |
Collapse
|
39
|
Brunker TJ, Green JC, O'Hare D. Electronic structures of mixed-sandwich complexes of cyclopentadienyl and Hydrotris(pyrazolyl)borate ligands with 3d transition metals. Inorg Chem 2003; 42:4366-81. [PMID: 12844309 DOI: 10.1021/ic030073u] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The electronic and magnetic properties of a series of mixed-sandwich complexes MCp(R)Tp (Cp(R) = Cp or Cp; Tp = hydrotris(pyrazolyl)borate; M = V, Cr, Fe, Co or Ni) have been studied and compared to their homoleptic analogues, MCp(R)(2) and MTp(2). Solid-state magnetic susceptibility measurements and EPR spectroscopic data indicate that complexes with d(3), d(6), and d(8) configurations are similar electronically to their metallocene analogues, except for FeCpTp, which displays a spin equilibrium (S = 0 if S = 2) in solution which was investigated by variable- temperature NMR spectroscopy. The d(2) complex [VCpTp](+) displays magnetic behavior consistent with an orbitally nondegenerate ground state. The d(4) species CrCpTp has a high-spin (S = 2) ground state. The d(7) species CoCpTp is high spin (S = 3/2) whereas its Cp analogue and [NiCpTp](+) are both low-spin (S = 1/2) species. The optical spectra of the d(3), d(6), and d(8) complexes were assigned in a fashion similar to the analogous metallocenes and ligand-field parameters (delta(1) = delta-sigma gap, delta(2) = sigma-pi gap for d-orbitals in axial symmetry) calculated. The analysis shows that for 15-electron species the total ligand-field splitting, delta(TOT), is larger than for their metallocene analogues, whereas for the 18-electron case Delta(TOT) is smaller and for 20-electron systems delta(TOT) is approximately the same. In all cases delta(2) is substantially reduced compared to the metallocenes, and in the majority of cases delta(1) is markedly larger. DFT calculations were performed to investigate further the nature of the ligand environment on the frontier orbitals in these complexes. Orbital energies and compositions were calculated and compared for a series of homoleptic and mixed-sandwich complexes of Ni(II) and across the 1st transition series for MCp(R)Tp species. The ability of Tp (vs Cp) to act as a delta-donor (with respect to the principal molecular axis) imparts significant ligand antibonding character to the delta-orbitals and results in decreased epsilon(pi)-epsilon(delta) values compared to the metallocenes and an increased tendency toward high-spin complexes in the mixed-sandwich complexes. Structure calculations were performed for CrCpTp, [VCpTp](+), and CoCpTp which show substantial distortions from ideal axial symmetry in their crystal structures. The origins of these distortions were confirmed to arise from unequal occupancy of near-degenerate delta- and pi-levels.
Collapse
Affiliation(s)
- Tim J Brunker
- Inorganic Chemistry Laboratory, South Parks Road, Oxford, OX1 3QR, UK
| | | | | |
Collapse
|
40
|
Brunker TJ, Green JC, O'Hare D. CrCpTp: a high-spin Cr(II) sandwich complex with a large structural distortion. Inorg Chem 2002; 41:1701-3. [PMID: 11925159 DOI: 10.1021/ic0255151] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
CrCpTp was synthesized from the reaction of [CrCpCl](2) and KTp. Magnetic measurements indicate it to have a high-spin (S = 2) electronic configuration from 5 to 300 K. A single-crystal X-ray study reveals bond lengths typical for a high-spin configuration and a pronounced Jahn-Teller distortion. The nature of this distortion was probed by DFT calculations and the variation in bond lengths successfully reproduced. The metal-based HOMO is significantly antibonding with respect to a single pyrazolyl ring only.
Collapse
Affiliation(s)
- Tim J Brunker
- Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR, U.K
| | | | | |
Collapse
|
41
|
van Staveren DR, Bill E, Bothe E, Bühl M, Weyhermüller T, Metzler-Nolte N. Fluxional processes in diamagnetic and paramagnetic allyl dicarbonyl and 2-methylallyl dicarbonyl molybdenum histidinato complexes as revealed by spectroscopic data and density functional calculations. Chemistry 2002; 8:1649-62. [PMID: 11933093 DOI: 10.1002/1521-3765(20020402)8:7<1649::aid-chem1649>3.0.co;2-u] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This work describes a detailed study on the structure and dynamics of pseudooctahedral low-valent complexes of the type [Mo(His-N(epsilon)-R)(eta-2-R'-allyl)(CO)(2)] (His=N(delta),N,O-L-histidinate; R=H, R'=H (1); R=C(2)H(4)CO(2)Me, R'=H (2); R=H, R'=Me (3); R=C(2)H(4)CO(2)Me, R'=Me (4)). These diamagnetic 18-electron complexes were comprehensively characterized spectroscopically and by X-ray crystallography. In the solid state, the (substituted) allyl ligand is in an endo position in all compounds, but it is trans to the His-N(delta) atom in 1 and 2, whereas it is trans to the carboxylate O atom for the 2-Me-allyl compounds 3 and 4. In solution, both isomers are present in a solvent-dependent equilibrium. The third isomer (allyl trans to His-NH(2)) is not spectroscopically observed in solution. This is in agreement with the results from density functional (DFT) computations (BPW 91 functional) for 1 and 3, which predict a considerably higher energy (+6.3 and +5.9 kJ mol(-1), respectively) for this isomer. A likely path for isomerization is calculated, which is consistent with the activation energy determined by variable temperature NMR measurements. At least for 3, the preferred path involves several intermediates and a rotation of the 2-Me-allyl ligand. For the paramagnetic 17-electron congeners, DFT predicts the exo isomer of 3(+) with the 2-Me-allyl ligand trans to the carboxylate O atom to be by far the most stable isomer. For 1(+), an endo-exo equilibrium between the isomers with the allyl ligand trans to the carboxylate O atom is suggested. These suggestions are confirmed by EPR spectroscopy on the electrochemically generated species, which show signals for one- (4) and two- (2) metal-containing compounds. The appearance of the EPR spectra may be rationalized by inspection of the SOMOs from DFT calculations of the species in question. The notion of a metal-centered oxidation is also substantiated by IR spectroelectrochemistry and by UV/Vis spectra of the 17-electron complexes. Upon depleting the metal of electron density, the stretching vibrations of the carbonyl ligands shift more than 100 cm(-1) to higher wavenumbers, and the carbonyl vibration of the metal-coordinated carboxylate shifts by about 50 cm(-1). A color change from yellow to green upon oxidation is observed visually and quantified by the appearance of a new band at 622 nm (2(+)) and 546 nm (4(+)), respectively.
Collapse
Affiliation(s)
- Dave R van Staveren
- Max-Planck-Institut für Strahlenchemie Stiftstrasse 34-36, 45 470 Mülheim/Ruhr, Germany
| | | | | | | | | | | |
Collapse
|