1
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Sergeieva T, Demirer TI, Wuttke A, Mata RA, Schäfer A, Linker GJ, Andrada DM. Revisiting the origin of the bending in group 2 metallocenes AeCp 2 (Ae = Be-Ba). Phys Chem Chem Phys 2023. [PMID: 37482883 PMCID: PMC10395002 DOI: 10.1039/d2cp05020j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/25/2023]
Abstract
Metallocenes are well-established compounds in organometallic chemistry, and can exhibit either a coplanar structure or a bent structure according to the nature of the metal center (E) and the cyclopentadienyl ligands (Cp). Herein, we re-examine the chemical bonding to underline the origins of the geometry and stability observed experimentally. To this end, we have analysed a series of group 2 metallocenes [Ae(C5R5)2] (Ae = Be-Ba and R = H, Me, F, Cl, Br, and I) with a combination of computational methods, namely energy decomposition analysis (EDA), polarizability model (PM), and dispersion interaction densities (DIDs). Although the metal-ligand bonding nature is mainly an electrostatic interaction (65-78%), the covalent character is not negligible (33-22%). Notably, the heavier the metal center, the stronger the d-orbital interaction with a 50% contribution to the total covalent interaction. The dispersion interaction between the Cp ligands counts only for 1% of the interaction. Despite that orbital contributions become stronger for heavier metals, they never represent the energy main term. Instead, given the electrostatic nature of the metallocene bonds, we propose a model based on polarizability, which faithfully predicts the bending angle. Although dispersion interactions have a fair contribution to strengthen the bending angle, the polarizability plays a major role.
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Affiliation(s)
- Tetiana Sergeieva
- Department of Chemistry, Saarland University, Campus Saarbrücken, 66123 Saarbrücken, Germany.
| | - T Ilgin Demirer
- Department of Chemistry, Saarland University, Campus Saarbrücken, 66123 Saarbrücken, Germany.
| | - Axel Wuttke
- Institute for Physical Chemistry, Georg-August-University Göttingen, Tammannstrasse 6, D-37077 Göttingen, Germany.
| | - Ricardo A Mata
- Institute for Physical Chemistry, Georg-August-University Göttingen, Tammannstrasse 6, D-37077 Göttingen, Germany.
| | - André Schäfer
- Department of Chemistry, Saarland University, Campus Saarbrücken, 66123 Saarbrücken, Germany.
| | - Gerrit-Jan Linker
- MESA+ Institute for Nanotechnology, University of Twente, 7522 NB Enschede, The Netherlands.
| | - Diego M Andrada
- Department of Chemistry, Saarland University, Campus Saarbrücken, 66123 Saarbrücken, Germany.
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2
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Schüler P, Görls H, Krieck S, Westerhausen M. One-Step Synthesis and Schlenk-Type Equilibrium of Cyclopentadienylmagnesium Bromides. Chemistry 2021; 27:15508-15515. [PMID: 34468050 PMCID: PMC8597043 DOI: 10.1002/chem.202102636] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Indexed: 12/23/2022]
Abstract
In the in situ Grignard metalation method (iGMM), the addition of bromoethane to a suspension of magnesium turnings and cyclopentadienes [C5 H6 (HCp), C5 H5 -Si(iPr)3 (HCpTIPS )] in diethyl ether smoothly yields heteroleptic [(Et2 O)Mg(CpR )(μ-Br)]2 (CpR =Cp (1), CpTIPS (2)). The Schlenk equilibrium of 2 in toluene leads to ligand exchange and formation of homoleptic [Mg(CpR )2 ] (3) and [(Et2 O)MgBr(μ-Br)]2 (4). Interfering solvation and aggregation as well as ligand redistribution equilibria hamper a quantitative elucidation of thermodynamic data for the Schlenk equilibrium of 2 in toluene. In ethereal solvents, mononuclear species [(Et2 O)2 Mg(CpTIPS )Br] (2'), [(Et2 O)n Mg(CpTIPS )2 ] (3'), and [(Et2 O)2 MgBr2 ] (4') coexist. Larger coordination numbers can be realized with cyclic ethers like tetrahydropyran allowing crystallization of [(thp)4 MgBr2 ] (5). The interpretation of the temperature-dependency of the Schlenk equilibrium constant in diethyl ether gives a reaction enthalpy ΔH and reaction entropy ΔS of -11.5 kJ mol-1 and 60 J mol-1 , respectively.
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Affiliation(s)
- Philipp Schüler
- Institute of Inorganic and Analytical ChemistryFriedrich Schiller University JenaHumboldtstraße 807743JenaGermany
| | - Helmar Görls
- Institute of Inorganic and Analytical ChemistryFriedrich Schiller University JenaHumboldtstraße 807743JenaGermany
| | - Sven Krieck
- Institute of Inorganic and Analytical ChemistryFriedrich Schiller University JenaHumboldtstraße 807743JenaGermany
| | - Matthias Westerhausen
- Institute of Inorganic and Analytical ChemistryFriedrich Schiller University JenaHumboldtstraße 807743JenaGermany
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3
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Kayastha P, Ramakrishnan R. High-throughput design of Peierls and charge density wave phases in Q1D organometallic materials. J Chem Phys 2021; 154:061102. [PMID: 33588537 DOI: 10.1063/5.0041717] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Soft-phonon modes of an undistorted phase encode a material's preference for symmetry lowering. However, the evidence is sparse for the relationship between an unstable phonon wavevector's reciprocal and the number of formula units in the stable distorted phase. This "1/q*-criterion" holds great potential for the first-principles design of materials, especially in low-dimension. We validate the approach on the Q1D organometallic materials space containing 1199 ring-metal units and identify candidates that are stable in undistorted (1 unit), Peierls (2 units), charge density wave (3-5 units), or long wave (>5 units) phases. We highlight materials exhibiting gap-opening as well as an uncommon gap-closing Peierls transition and discuss an example case stabilized as a charge density wave insulator. We present the data generated for this study through an interactive publicly accessible Big Data analytics platform (https://moldis.tifrh.res.in/data/rmq1d) facilitating limitless and seamless data-mining explorations.
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Affiliation(s)
- Prakriti Kayastha
- Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad 500107, India
| | - Raghunathan Ramakrishnan
- Centre for Interdisciplinary Sciences, Tata Institute of Fundamental Research, Hyderabad 500107, India
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4
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Pal R, Mebs S, Shi MW, Jayatilaka D, Krzeszczakowska JM, Malaspina LA, Wiecko M, Luger P, Hesse M, Chen YS, Beckmann J, Grabowsky S. Linear MgCp* 2 vs Bent CaCp* 2: London Dispersion, Ligand-Induced Charge Localizations, and Pseudo-Pregostic C-H···Ca Interactions. Inorg Chem 2018; 57:4906-4920. [PMID: 29671589 DOI: 10.1021/acs.inorgchem.7b03079] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In the family of metallocenes, MgCp*2 (Cp* = pentamethylcyclopentadienyl) exhibits a regular linear sandwich structure, whereas CaCp*2 is bent in both the gas phase and solid state. Bending is typically observed for metal ions which possess a lone pair. Here, we investigate which electronic differences cause the bending in complexes lacking lone pairs at the metal atoms. The bent gas-phase geometry of CaCp*2 suggests that the bending must have an intramolecular origin. Geometry optimizations with and without dispersion effects/d-type polarization functions on MCp2 and MCp*2 gas-phase complexes (M = Ca, Mg) establish that attractive methyl···methyl London dispersion interactions play a decisive role in the bending in CaCp*2. A sufficient polarizability of the metal to produce a shallow bending potential energy curve is a prerequisite but is not the reason for the bending. Concomitant ligand-induced charge concentrations and localizations at the metal atoms are studied in further detail, for which real-space bonding and orbital-based descriptors are used. Low-temperature crystal structures of MgCp*2 and CaCp*2 were determined which facilitated the identification and characterization of intermolecular pseudo-pregostic interactions, C-H···Ca, in the CaCp*2 crystal structure.
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Affiliation(s)
- Rumpa Pal
- Universität Bremen , Institut für Anorganische Chemie und Kristallographie , Leobener Straße 3 and 7 , 28359 Bremen , Germany
| | - Stefan Mebs
- Freie Universität Berlin , Institut für Experimentalphysik , Arnimallee 14 , 14195 Berlin , Germany
| | - Ming W Shi
- The University of Western Australia, School of Molecular Sciences , 35 Stirling Highway , Perth Western Australia 6009 , Australia
| | - Dylan Jayatilaka
- The University of Western Australia, School of Molecular Sciences , 35 Stirling Highway , Perth Western Australia 6009 , Australia
| | - Joanna M Krzeszczakowska
- University of Warsaw , Biological and Chemical Research Centre, Chemistry Department , Zwirki i Wigury 101 , 02-089 Warsaw , Poland
| | - Lorraine A Malaspina
- Universität Bremen , Institut für Anorganische Chemie und Kristallographie , Leobener Straße 3 and 7 , 28359 Bremen , Germany
| | - Michal Wiecko
- Freie Universität Berlin , Institut für Chemie und Biochemie, Anorganische Chemie , Fabeckstraße 36a , 14195 Berlin , Germany
| | - Peter Luger
- Freie Universität Berlin , Institut für Chemie und Biochemie, Anorganische Chemie , Fabeckstraße 36a , 14195 Berlin , Germany
| | - Malte Hesse
- Universität Bremen , Institut für Anorganische Chemie und Kristallographie , Leobener Straße 3 and 7 , 28359 Bremen , Germany
| | - Yu-Sheng Chen
- ChemMatCARS, Center for Advanced Radiation Sources, c/o Advanced Photon Source/ANL , The University of Chicago , 9700 South Cass Avenue , Building 434D, Argonne , Illinois 60439 , United States
| | - Jens Beckmann
- Universität Bremen , Institut für Anorganische Chemie und Kristallographie , Leobener Straße 3 and 7 , 28359 Bremen , Germany
| | - Simon Grabowsky
- Universität Bremen , Institut für Anorganische Chemie und Kristallographie , Leobener Straße 3 and 7 , 28359 Bremen , Germany
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5
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Momin A, Carter L, Yang Y, McDonald R, Essafi (née Labouille) S, Nief F, Del Rosal I, Sella A, Maron L, Takats J. To Bend or Not To Bend: Experimental and Computational Studies of Structural Preference in Ln(TpiPr2)2 (Ln = Sm, Tm). Inorg Chem 2014; 53:12066-75. [DOI: 10.1021/ic501816v] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Aurélien Momin
- Laboratoire de Chimie Moléculaires, CNRS, Ecole Polytechnique, 91128 Palaiseau, France
| | - Lee Carter
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2
| | - Yi Yang
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2
| | - Robert McDonald
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2
| | | | - François Nief
- Laboratoire de Chimie Moléculaires, CNRS, Ecole Polytechnique, 91128 Palaiseau, France
| | - Iker Del Rosal
- Laboratoire de Physique et Chimie des Nanoobjets,
INSA, Université Paul Sabatier, 135 Avenue de Rangueil, 31077 Toulouse Cedex, France
| | - Andrea Sella
- Department of Chemistry, University College London, 20 Gordon Street, London, WC1H 0AJ, United Kingdom
| | - Laurent Maron
- Laboratoire de Physique et Chimie des Nanoobjets,
INSA, Université Paul Sabatier, 135 Avenue de Rangueil, 31077 Toulouse Cedex, France
| | - Josef Takats
- Department of Chemistry, University of Alberta, Edmonton, AB, Canada T6G 2G2
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6
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Novel amino acids indices based on quantum topological molecular similarity and their application to QSAR study of peptides. Amino Acids 2010; 40:1169-83. [DOI: 10.1007/s00726-010-0741-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2010] [Accepted: 08/31/2010] [Indexed: 10/19/2022]
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7
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Lindsjö M, Fischer A, Kloo L. Dimorphic (Ba[GaCl(4)](2))(3).2C(6)H(6): a case of coordination extremes. Dalton Trans 2010; 39:1467-9. [PMID: 20104305 DOI: 10.1039/b912154b] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Two new dimorphic tris[barium bis(tetrachloro gallate]) bisbenzene formed by the same molecular building blocks have been isolated and structurally characterized, showing an unprecedented inorganic as well as mixed organic/inorganic coordination.
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Affiliation(s)
- Martin Lindsjö
- Royal Institute of Technology, Inorganic Chemistry, S-10044, Stockholm, Sweden
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8
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Strukturen von polaren Magnesiumorganylen: Synthese und Struktur von Basen-Addukten des Bis(cyclopentadienyl)magnesiums. Z Anorg Allg Chem 2008. [DOI: 10.1002/zaac.200700445] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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9
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Farrugia LJ, Evans C, Tegel M. Chemical Bonds without “Chemical Bonding”? A Combined Experimental and Theoretical Charge Density Study on an Iron Trimethylenemethane Complex. J Phys Chem A 2006; 110:7952-61. [PMID: 16789785 DOI: 10.1021/jp061846d] [Citation(s) in RCA: 129] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
High-resolution X-ray diffraction data, in conjunction with DFT(B3LYP) quantum calculations, have been used in a QTAIM analysis of the charge density in the trimethylenemethane (TMM) complex Fe(eta(4)-C[CH(2)](3))(CO)(3). The agreement between the theoretical and experimental topological properties is excellent. Only one bond path is observed between the TMM ligand and the Fe atom, from the central C(alpha) atom. However, much evidence, including from the delocalization indices and the source function, suggests that there is a strong chemical interaction between the Fe and C(beta) atoms, despite the formal lack of chemical bonding according to QTAIM.
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Affiliation(s)
- Louis J Farrugia
- WestCHEM, Department of Chemistry, University of Glasgow, Scotland.
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10
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Egorova AN, Tsirel’son VG. Electron distribution and chemical bonding in M3(XO4)2 molecules (M = Mg, Cu; X = P, V) as determined by Ab initio calculations. RUSS J INORG CHEM+ 2006. [DOI: 10.1134/s0036023606060143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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11
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Lobayan RM, Sosa GL, Jubert AH, Peruchena NM. Some Electronic Correlation Effects in the Topological Analysis of the Laplacian of the Electronic Charge Density in C-n-Butonium Cations. J Phys Chem A 2004; 109:181-90. [PMID: 16839104 DOI: 10.1021/jp0469923] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In this work, we present a topological study of the Laplacian of the electronic density using a 6-311++G basis set, at Hartree-Fock (HF) and second-order Møller-Plesset (MP2) (full-electron and frozen-core) levels of theory, for the carbocations 2-C-n-butonium generated upon the insertion of a proton into the secondary C-C bond during the protonation of n-butane. The charge concentration, CC, critical points of the Laplacian distribution at each valence shell, VS, of carbon atoms, and the charge concentration closer to hydrogen atoms are studied. Also, the bonding critical points of the electronic density are analyzed. We analyze some effects that Coulomb correlation has on topological features of the electronic distribution. It is shown that they are mainly reflected in a decreasing of the charge concentrations at the VS and in a contraction of the VS to the nuclei. They are more pronounced over C-C bonds than in C-H bonds. The sensitivity of some parameters derived from this topological analysis to the correlation effect of core electrons and subtle effects related to hyperconjugative interactions are shown. Some consequences of different schemes (double and triple split-valence basis set with diffuse and polarization functions) in the definition of subtle VS charge concentrations at 3c-2e bond paths are presented. It is also demonstrated here how the facts that allow us to understand the MP2 stability order found in the carbocationic species 2-C-n-butonium > 1-C-n-butonium > 2-H-n-butonium > 1-H-n-butonium are similarly depicted at correlated and uncorrelated levels of calculation.
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Affiliation(s)
- Rosana M Lobayan
- Departamento de Física and Lab. Estructura Molecular y Propiedades, Area de Química Física, Facultad de Ciencias Exactas y Naturales y Agrimensura, UNNE, Avda. Libertad 5460, (3400) Corrientes, Argentina
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12
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Wang GT, Creighton JR. Complex Formation between Magnesocene (MgCp2) and NH3: Implications for p-Type Doping of Group III Nitrides and the Mg Memory Effect. J Phys Chem A 2004. [DOI: 10.1021/jp036494e] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- George T. Wang
- Sandia National Laboratories, P.O. Box 5800, MS-0601, Albuquerque, New Mexico 87185
| | - J. Randall Creighton
- Sandia National Laboratories, P.O. Box 5800, MS-0601, Albuquerque, New Mexico 87185
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13
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Lobayan RM, Sosa GL, Jubert AH, Peruchena NM. Exploratory Topological Study of the Laplacian of the Electronic Charge Density in n-Butonium Cations. J Phys Chem A 2004. [DOI: 10.1021/jp049717p] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. M. Lobayan
- Area de Química Física, Facultad de Ciencias Exactas y Naturales y Agrimensura, UNNE, Avda. Libertad 5460, (3400) Corrientes, Argentina, and CEQUINOR (CONICET, UNLP), Departamento de Química, Facultad de Ciencias Exactas and Facultad de Ingeniería, UNLP, C.C. 962, Calle 47 y 115 (1900) La Plata, Argentina
| | - G. L. Sosa
- Area de Química Física, Facultad de Ciencias Exactas y Naturales y Agrimensura, UNNE, Avda. Libertad 5460, (3400) Corrientes, Argentina, and CEQUINOR (CONICET, UNLP), Departamento de Química, Facultad de Ciencias Exactas and Facultad de Ingeniería, UNLP, C.C. 962, Calle 47 y 115 (1900) La Plata, Argentina
| | - A. H. Jubert
- Area de Química Física, Facultad de Ciencias Exactas y Naturales y Agrimensura, UNNE, Avda. Libertad 5460, (3400) Corrientes, Argentina, and CEQUINOR (CONICET, UNLP), Departamento de Química, Facultad de Ciencias Exactas and Facultad de Ingeniería, UNLP, C.C. 962, Calle 47 y 115 (1900) La Plata, Argentina
| | - N. M. Peruchena
- Area de Química Física, Facultad de Ciencias Exactas y Naturales y Agrimensura, UNNE, Avda. Libertad 5460, (3400) Corrientes, Argentina, and CEQUINOR (CONICET, UNLP), Departamento de Química, Facultad de Ciencias Exactas and Facultad de Ingeniería, UNLP, C.C. 962, Calle 47 y 115 (1900) La Plata, Argentina
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14
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Harvey M, Quisenberry K, Hanusa T, Young Jr. V. A Homologous Series of Base‐Free Organo(alkaline‐earth) Metallocenes: Synthesis and Molecular Structures of [1,2,4‐(SiMe
3
)
3
C
5
H
2
]
2
(Ca, Sr, Ba). Eur J Inorg Chem 2003. [DOI: 10.1002/ejic.200300284] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Melanie J. Harvey
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, U.S.A., Fax: (internat.) + 1‐615/343‐1234
| | - Keith T. Quisenberry
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, U.S.A., Fax: (internat.) + 1‐615/343‐1234
| | - Timothy P. Hanusa
- Department of Chemistry, Vanderbilt University, Nashville, TN 37235, U.S.A., Fax: (internat.) + 1‐615/343‐1234
| | - Victor G. Young Jr.
- X‐ray Crystallographic Laboratory, Chemistry Department, University of Minnesota, Minneapolis, MN 55455, U.S.A., Fax: (internat.) + 1‐612/626‐7541
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15
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Pillet S, Wu G, Kulsomphob V, Harvey BG, Ernst RD, Coppens P. Investigation of Zr-C, Zr-N, and potential agostic interactions in an organozirconium complex by experimental electron density analysis. J Am Chem Soc 2003; 125:1937-49. [PMID: 12580621 DOI: 10.1021/ja021133i] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The crystal structure and electron density (ED) distribution of an imine coupling product with an open zirconocene, Zr(2,4-C(7)H(11))[(i-Pr)NCHPhCH(2)CMe=CHCMe=CH(2)] (C(7)H(11) = dimethylpentadienyl), have been derived from accurate synchrotron X-ray diffraction measurements. The molecular structure reveals asymmetric coordination of Zr by the pentadienyl (2,4-C(7)H(11)) ligand (<Zr-C> = 2.56(6) A), the butadiene fragment (<Zr-C> = 2.43(5) A), and the amide nitrogen atom (Zr-N = 2.0312(5) A) of the second ligand. The study of the ED and its topological analysis affords new insight into the bonding and electronic structure of the title zirconium complex. The interactions between the metal center and the ligands are represented by a Zr-N bond path and one Zr-C bond path with each of the pentadienyl and butadiene moieties, contrary to the usually depicted global metal-ligand bonding. The butadiene and pentadienyl groups exhibit a polarization of the corresponding pi-like ED in the C-Zr directions, indicating that the whole conjugated systems are nonetheless involved. The 4d atomic orbitals of Zr exhibit unusual populations according to ligand field considerations, which reveal a high degree of sigma-donation from the conjugated pi systems of both ligands. As deduced from numerical integration over the topologically defined atomic basins, the Zr to ligand charge transfer is 1.48 e to the C(17)NH(24) ligand and 0.68 e to dimethylpentadienyl. Topological analysis of a short intramolecular Zr.(C,H) contact provides no indication of the presence of agostic interactions, despite a small Zr-N-C angle of 102.87(4) degrees. Thus, no bond path and BCP (bond critical point) of the ED are found in the Zr.(C,H) region, which would have provided evidence for such direct interactions, nor is there any evidence for charge accumulation between the Zr and H atoms, or for lengthening of the C-H bond involved in the putative interaction. These characteristics, similar to those in other distorted situations, may be common for other electron-deficient d(0) complexes.
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Affiliation(s)
- Sebastien Pillet
- Department of Chemistry, University of New York at Buffalo, Buffalo, New York 14260, USA
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16
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Hanusa TP. New Developments in the Cyclopentadienyl Chemistry of the Alkaline-Earth Metals. Organometallics 2002. [DOI: 10.1021/om020168o] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Timothy P. Hanusa
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
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17
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Affiliation(s)
- Martin Kaupp
- Institut für Anorganische Chemie Universität Würzburg Am Hubland, 97074 Würzburg, Germany, Fax: (+49) 931‐888‐7135
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18
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Abstract
Under certain circumstances, metal complexes with a formal d(0) electronic configuration may exhibit structures that violate the traditional structure models, such as the VSEPR concept or simple ionic pictures. Some examples of such behavior, such as the bent gas-phase structures of some alkaline earth dihalides, or the trigonal prismatic coordination of some early transition metal chalcogenides or pnictides, have been known for a long time. However, the number of molecular examples for "non-VSEPR" structures has increased dramatically during the past decade, in particular in the realm of organometallic chemistry. At the same time, various theoretical models have been discussed, sometimes controversially, to explain the observed, unusual structures. Many d(0) systems are important in homogeneous and heterogeneous catalysis, biocatalysis (e.g. molybdenum or tungsten enzymes), or materials science (e.g. ferroelectric perovskites or zirconia). Moreover, their electronic structure without formally nonbonding d orbitals makes them unique starting points for a general understanding of structure, bonding, and reactivity of transition metal compounds. Here we attempt to provide a comprehensive view, both of the types of deviations of d(0) and related complexes from regular coordination arrangements, and of the theoretical framework that allows their rationalization. Many computational and experimental examples are provided, with an emphasis on homoleptic mononuclear complexes. Then the factors that control the structures are discussed in detail. They are a) metal d orbital participation in sigma bonding, b) polarization of the outermost core shells, c) ligand repulsion, and d) pi bonding. Suggestions are made as to which of the factors are the dominant ones in certain situations. In heteroleptic complexes, the competition of sigma and pi bonding of the various ligands controls the structures in a complicated fashion. Some guidelines are provided that should help to better understand the interrelations. Bent's rule is of only very limited use in these types of systems, because of the paramount influence of pi bonding. Finally, computed and measured structures of multinuclear complexes are discussed, including possible consequences for the properties of bulk solids.
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Affiliation(s)
- Martin Kaupp
- Institut für Anorganische Chemie Universität Würzburg Am Hubland, 97074 Würzburg (Germany)
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19
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20
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Malcolm NOJ, Popelier PLA. On the Full Topology of the Laplacian of the Electron Density II: Umbrella Inversion of the Ammonia Molecule. J Phys Chem A 2001. [DOI: 10.1021/jp0113937] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Paul L. A. Popelier
- Department of Chemistry, U.M.I.S.T., 88 Sackville Street, Manchester M60 1QD, UK
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Smith JD, Hanusa TP. Trends in the Structures and Energetics of the Group 14 Metallocenes (C5H5)2M (M = Si−Pb): A Density Functional Theory Study. Organometallics 2001. [DOI: 10.1021/om010213c] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. Dominic Smith
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Timothy P. Hanusa
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
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22
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Zheng X, Englert U, Herberich GE, Rosenplänter J. Syntheses and structures of Mg(C5H5BMe)2, Mg(3,5-Me2C5H3BNMe2)2, the 2,2'-bipyridine adduct Mg(C5H5BMe)2(bipy), and the N-bonded aminoboratabenzene species Mg(3,5-Me2C5H3BNMe2)2(THF)2. Inorg Chem 2000; 39:5579-85. [PMID: 11151358 DOI: 10.1021/ic000575x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The donor-free magnesocene analogues bis(1-methylboratabenzene)magnesium (1) and bis[3,5-dimethyl-1- (dimethylamino)boratabenzene]magnesium (2) are synthesized in good yields by the reactions of dimethylmagnesium with (trimethylstannyl)dihydroborinine precursors 3 and 4. In the crystalline state, both 1 and 2 possess sandwich structures with eta 6-coordinated boratabenzene ligands and display crystallographic centrosymmetry. Compound 1 reacts with the nitrogen donor 2,2'-bipyridine to give the Lewis base adduct (1)(bipy) (identical to 5). In the crystal structure of 5, one boratabenzene ligand is eta 6-bonded to the central metal while the other ligand adopts an eta 1-bonding mode. Crystallization of compound 2 from THF produces the solvate (2)(THF)2 (identical to 6), which exhibits a distorted tetrahedral N2O2 coordination environment around the magnesium atom. The average Mg-N bond distance is 2.141(3) A, and the N-Mg-N angle is 148.0(1) degrees. The observation of an aminoboratabenzene that is solely sigma-bonded to a metal is without precedent.
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Affiliation(s)
- X Zheng
- Institut für Anorganische Chemie, Technische Hochschule Aachen, 52056 Aachen, Germany
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Abstract
The synthesis and structural characterization of a family of barium thiolates and selenolates is described. The thiolates were synthesized by metallation of thiols, the selenolates by reductive insertion of the metal into the selenium-selenium bond of diorganodiselenides. Both reaction sequences were carried out by using barium metal dissolved in ammonia; this afforded barium thiolates and selenolates in good yield and purity. The structural principles displayed in the target compounds span a wide range of solid-state formulations, including monomeric and dimeric species, and separated ion triples, namely [Ba(thf)4(SMes*)2] (1; Mes* = 2,4,6-tBU3C6H2), [Ba(thf)4(SeMes*)2] (2), [Ba([18]crown-6)(hmpa)2][(SeMes*)2] (3), the dimeric [(Ba(py)3(thf)(SeTrip)2)2] (4; py = pyridine, Trip = 2,4.6-iPr3C6H2), and [Ba([18]crown-6)(SeTrip)2] (5). The full range of association modes is completed by [Ba([18]crown-6)(hmpa)SMes*][SMes*] (6) communicated earlier by this group. In the solid state, this compound displays an intermediate ion coordination mode: one anion is bound to the metal, while the second one is unassociated. Together these compounds provide structural information about all three different association modes for alkaline earth metal derivatives. This collection of structural data allows important conclusions about the influence of solvation and ligation on structural trends.
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Affiliation(s)
- K Ruhlandt-Senge
- Department of Chemistry, Syracuse University, Center for Science and Technology, NY 13244-4100, USA.
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Harvey MJ, Hanusa TP. Mono(cyclopentadienyl) Complexes of Calcium, Strontium, and Barium, {[C5(SiMe3)3H2](Ca,Sr,Ba)I(thf)n}x. Influence of Alkali-Metal Cations on Ligand Exchange Reactions. Organometallics 2000. [DOI: 10.1021/om991003r] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Melanie J. Harvey
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Timothy P. Hanusa
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
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Dinnebier RE, Behrens U, Olbrich F. Solid State Structures of Cyclopentadienyllithium, -sodium, and -potassium. Determination by High-Resolution Powder Diffraction. Organometallics 1997. [DOI: 10.1021/om9700122] [Citation(s) in RCA: 142] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert E. Dinnebier
- Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, D-39106 Magdeburg, Germany
| | - Ulrich Behrens
- Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, D-39106 Magdeburg, Germany
| | - Falk Olbrich
- Chemisches Institut, Otto-von-Guericke-Universität Magdeburg, Universitätsplatz 2, D-39106 Magdeburg, Germany
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