1
|
Leach IF, Speelman T, Somsen C, Klein JEMN, Havenith RWA. Revisiting sp 2 Dilithio Methandiides: From Geometric Curiosity to Simple Bonding Description. Chemistry 2023; 29:e202301911. [PMID: 37427720 DOI: 10.1002/chem.202301911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 07/07/2023] [Accepted: 07/10/2023] [Indexed: 07/11/2023]
Abstract
The reported tetracoordinate dilithio methandiide complex from Liddle and co-workers (1) is investigated from a coordination chemistry perspective, to probe the origin of its intriguing geometry. Through the application of a variety of computational techniques, non-covalent (steric, electrostatic) interactions are found to be dominant. Further, we arrive at a bonding description which emphasizes the tricoordinate sp2 -hybridized nature of the central methandiide carbon, differing somewhat from the original proposal. Thus, 1 is distinct from other dilithio methandiides since it contains only one C-Li σ-bond, and is found to be comparable to a simple aryllithium compound, phenyllithium.
Collapse
Affiliation(s)
- Isaac F Leach
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Tom Speelman
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Chiel Somsen
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Johannes E M N Klein
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Remco W A Havenith
- Molecular Inorganic Chemistry, Stratingh Institute for Chemistry, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
- Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
- Ghent Quantum Chemistry Group, Department of Chemistry, Ghent University, 9000, Gent, Belgium
| |
Collapse
|
2
|
Structure and Bonding in Planar Hypercoordinate Carbon Compounds. CHEMISTRY 2022. [DOI: 10.3390/chemistry4040113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The term hypercoordination refers to the extent of the coordination of an element by its normal value. In the hypercoordination sphere, the element can achieve planar and/or non-planar molecular shape. Hence, planar hypercoordinate carbon species violate two structural rules: (i) The highest coordination number of carbon is four and (ii) the tetrahedral orientation by the connected elements and/or groups. The unusual planar orientations are mostly stabilized by the electronic interactions of the central atom with the surrounding ligands. In this review article, we will talk about the current progress in the theoretical prediction of viable planar hypercoordinate carbon compounds. Primary knowledge of the planar hypercoordinate chemistry will lead to its forthcoming expansion. Experimental and theoretical interests in planar tetracoordinate carbon (ptC), planar pentacoordinate carbon (ppC), and planar hexacoordinate carbon (phC) are continued. The proposed electronic and mechanical strategies are helpful for the designing of the ptC compounds. Moreover, the 18-valence electron rule can guide the design of new ptC clusters computationally as well as experimentally. However, the counting of 18-valence electrons is not a requisite condition to contain a ptC in a cluster. Furthermore, this ptC idea is expanded to the probability of a greater coordination number of carbon in planar orientations. Unfortunately, until now, there are no such logical approaches to designing ppC, phC, or higher-coordinate carbon molecules/ions. There exist a few global minimum structures of phC clusters identified computationally, but none have been detected experimentally. All planar hypercoordinate carbon species in the global minima may be feasible in the gas phase.
Collapse
|
3
|
Wang H, Liu FL. How to Accomplish a Square C(N) 4 Substructure of the Planar Tetracoordinate Carbon. ACS OMEGA 2020; 5:32583-32590. [PMID: 33376895 PMCID: PMC7758975 DOI: 10.1021/acsomega.0c04876] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 11/20/2020] [Indexed: 06/12/2023]
Abstract
Nitrogen-based groups are usually not used as ligands to coordinate to the ptC atom. However, here we reported only nitrogen-based ligands to accomplish a theoretically successful square planar C(N)4 substructure. The first difficulty in accomplishing a square ptC(N)4 substructure is to conquer the tremendous strain from the planar to tetrahedral arrangements, and the second is to restrict it in a suitable system with the right symmetry. We designed several neutral molecules with the square ptC(N)4 substructures, and the molecules were studied using the density functional theory method at the B3LYP/6-311++G(3df,3pd) and TPSSh/6-311++G(3df,3pd) level of theory. The results of this work show that the molecules are all real minima on the potential energy surface and successfully achieved the square ptC(N)4 substructure in the theoretical method. The group orbitals among the square ptC(N)4 arrangement in the D 2d symmetry have been discussed and used to investigate the bonding interactions among all atoms in the square ptC(N)4 substructure. Usually, the ptC systems have 18 valence electrons, but the present ptC systems mentioned in this work have 24 valence electrons, which is unusual for ptC.
Collapse
Affiliation(s)
- Haiyan Wang
- College of Chemistry, Chemical Engineering
and Materials Science, Collaborative Innovation Center of Functionalized
Probes for Chemical Imaging in Universities of Shandong, Key Laboratory
of Molecular and Nano Probes, Ministry of Education, Shandong Provincial
Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, People’s Republic of China
| | - Feng-Ling Liu
- College of Chemistry, Chemical Engineering
and Materials Science, Collaborative Innovation Center of Functionalized
Probes for Chemical Imaging in Universities of Shandong, Key Laboratory
of Molecular and Nano Probes, Ministry of Education, Shandong Provincial
Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, People’s Republic of China
| |
Collapse
|
4
|
Saumya MJ, Raghi KR, Sherin DR, Haridas KR, Manojkumar TK. Butterfly Methanes: Designing a Novel Class of anti-van't Hoff Carbons. Chemphyschem 2020; 21:2272-2278. [PMID: 32841480 DOI: 10.1002/cphc.202000501] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 08/22/2020] [Indexed: 11/09/2022]
Abstract
Among different possible non-classical structures, the stabilization of half-planar tetracoordinate carbon conformation is believed to be the most difficult one. Herein, we designed three types of half-planar tetracoordinate carbon compounds computationally by employing hybrid stabilization effects of substituents. The axial hydrogens of unstable half-planar methane are substituted with π-acceptor and σ-donor substituents such as -BH2 , -Li and the equatorial substituents selected are a combination of electropositive atoms (σ-donors)/electronegative atoms (σ-acceptors and π-donors). To establish the stabilization factors, we conducted a detailed study on vibrational frequency analysis, molecular orbital analysis (including Natural Bond Orbitals) and electrostatic potential (ESP) analysis of optimized molecular geometries using density functional theory.
Collapse
Affiliation(s)
- M J Saumya
- School of Chemical Sciences, Kannur University, Payyanur Campus, Edat P.O, Kannur, 670327, Kerala, India.,Indian Institute of Information Technology and Management-Kerala Technopark Campus, Trivandrum, 695581, Kerala, India
| | - K R Raghi
- School of Chemical Sciences, Kannur University, Payyanur Campus, Edat P.O, Kannur, 670327, Kerala, India.,Indian Institute of Information Technology and Management-Kerala Technopark Campus, Trivandrum, 695581, Kerala, India
| | - D R Sherin
- Indian Institute of Information Technology and Management-Kerala Technopark Campus, Trivandrum, 695581, Kerala, India
| | - K R Haridas
- School of Chemical Sciences, Kannur University, Payyanur Campus, Edat P.O, Kannur, 670327, Kerala, India
| | - T K Manojkumar
- School of Chemical Sciences, Kannur University, Payyanur Campus, Edat P.O, Kannur, 670327, Kerala, India.,Indian Institute of Information Technology and Management-Kerala Technopark Campus, Trivandrum, 695581, Kerala, India
| |
Collapse
|
5
|
Yañez O, Vásquez-Espinal A, Báez-Grez R, Rabanal-León WA, Osorio E, Ruiz L, Tiznado W. Carbon rings decorated with group 14 elements: new aromatic clusters containing planar tetracoordinate carbon. NEW J CHEM 2019. [DOI: 10.1039/c9nj01022j] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A simple and chemically intuitive approach is used to design ptC-containing E–C clusters (E = Si–Pb).
Collapse
Affiliation(s)
- Osvaldo Yañez
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
- Chile
| | - Alejandro Vásquez-Espinal
- Computational and Theoretical Chemistry Group
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
| | - Rodrigo Báez-Grez
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
- Chile
| | - Walter A. Rabanal-León
- Laboratorio de Química Inorgánica y Organometálica
- Departamento de Química Analítica e Inorgánica
- Facultad de Ciencias Químicas
- Universidad de Concepción
- Casilla 160-C
| | - Edison Osorio
- Facultad de Ciencias Naturales y Matemáticas
- Universidad de Ibagué
- Ibagué
- Colombia
| | - Lina Ruiz
- Instituto de Ciencias Biomédicas
- Facultad Ciencias de la Salud
- Universidad Autónoma de Chile
- Santiago
- Chile
| | - William Tiznado
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- Santiago
- Chile
| |
Collapse
|
6
|
Zhang C, Fan F, Wang Z, Song J, Li C, Mo Y. B-Heterocyclic Carbene Arising from Charge Shift: A Computational Verification. Chemistry 2018; 24:10216-10223. [PMID: 29714815 DOI: 10.1002/chem.201801620] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Indexed: 01/24/2023]
Abstract
1-Borabicyclo[1.1.0]but-2(3)-ene (1BB) is a singlet biradical with two single electrons that can form an ionic resonance structure through a charge shift. The ionic resonance structure is a B-heterocyclic carbene (BHC), which can act as a carbene, Lewis base, or L- and Z-type ligand, to give adducts and complexes. Through a range of quantum methods, four types of stable compounds (A-D) derived from 1BB have been designed. These compounds retain the unique features of 1BB. As a consequence, the structures, stability, and Wiberg bond indices of the Lewis adducts of A-D with Lewis acids (BePh2 , BH3 , AlH3 , AlCl3 , C5 BH5 , and C13 BH9 ) and CuI , AgI , and AuI complexes have been investigated. Results show that A-D can indeed react as carbenes. Interestingly, compounds A-D, as L-type ligands, can attach to BePh2 , BH3 , AlH3 , AlCl3 , C5 BH5 , C13 BH9 , and CuCl and form compounds with planar tetracoordinate carbon (ptC), whereas Z-type ligands A-D can bind to AgCl and AuCl to provide complexes with planar tetracoordinate boron (ptB). In addition, the binuclear complexes of ClX(1BB)CuCl (X=Ag, Au) have been studied and A-D behave as both L- and Z-type ligands, in which these complexes contain both ptC and ptB. Thus, a novel method for designing compounds with ptC and ptB is presented. These rationally designed compounds involve the elements of carbene, ptC, ptB, and L- and Z-type ligands, and are expected to be unique and useful in experimental chemistry once they are synthesized.
Collapse
Affiliation(s)
- Congjie Zhang
- Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P.R. China
| | - Fan Fan
- Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P.R. China
| | - Zhimin Wang
- Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, P.R. China
| | - Jinshuai Song
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P.R. China
| | - Chunsen Li
- State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, P.R. China
| | - Yirong Mo
- Department of Chemistry, Western Michigan University, Kalamazoo, MI, 49008, USA
| |
Collapse
|
7
|
Yañez O, Vásquez-Espinal A, Pino-Rios R, Ferraro F, Pan S, Osorio E, Merino G, Tiznado W. Exploiting electronic strategies to stabilize a planar tetracoordinate carbon in cyclic aromatic hydrocarbons. Chem Commun (Camb) 2017; 53:12112-12115. [DOI: 10.1039/c7cc06248f] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A new approach to stabilize compounds containing a planar tetracoordinate carbon (ptC), embedded in aromatic hydrocarbons, is presented herein.
Collapse
Affiliation(s)
- O. Yañez
- Doctorado en Fisicoquímica Molecular
- Facultad de Ciencias Exactas
- Universidad Andres Bello
- República 275
- Santiago
| | - A. Vásquez-Espinal
- Departamento de Física Aplicada
- Centro de Investigación y de Estudios Avanzados Unidad Mérida
- Km. 6 Antigua carretera a Progreso
- Apdo. Postal 73
- Mérida
| | - R. Pino-Rios
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas Universidad Andres Bello
- República 275
- Santiago
- Chile
| | - F. Ferraro
- Departamento de Ciencias Básicas
- Universidad Católica Luis Amigó, SISCO
- Transversal 51A # 67B 90
- Medellín
- Colombia
| | - S. Pan
- Departamento de Física Aplicada
- Centro de Investigación y de Estudios Avanzados Unidad Mérida
- Km. 6 Antigua carretera a Progreso
- Apdo. Postal 73
- Mérida
| | - E. Osorio
- Departamento de Ciencias Básicas
- Universidad Católica Luis Amigó, SISCO
- Transversal 51A # 67B 90
- Medellín
- Colombia
| | - G. Merino
- Departamento de Física Aplicada
- Centro de Investigación y de Estudios Avanzados Unidad Mérida
- Km. 6 Antigua carretera a Progreso
- Apdo. Postal 73
- Mérida
| | - W. Tiznado
- Departamento de Ciencias Químicas
- Facultad de Ciencias Exactas Universidad Andres Bello
- República 275
- Santiago
- Chile
| |
Collapse
|
8
|
Vogt-Geisse S, Wu JIC, Schleyer PVR, Schaefer HF. Bonding, aromaticity, and planar tetracoordinated carbon in Si2CH2 and Ge2CH2. J Mol Model 2015; 21:217. [PMID: 26232183 DOI: 10.1007/s00894-015-2736-8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Accepted: 06/15/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Stefan Vogt-Geisse
- Facultad de Química, Pontifícia Universidad Católica de Chile, Santiago, Chile,
| | | | | | | |
Collapse
|
9
|
Yang LM, Ganz E, Chen Z, Wang ZX, Schleyer PVR. Vier Jahrzehnte Chemie der planar hyperkoordinierten Verbindungen. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201410407] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
10
|
Yang LM, Ganz E, Chen Z, Wang ZX, Schleyer PVR. Four Decades of the Chemistry of Planar Hypercoordinate Compounds. Angew Chem Int Ed Engl 2015; 54:9468-501. [DOI: 10.1002/anie.201410407] [Citation(s) in RCA: 165] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2014] [Indexed: 11/09/2022]
|
11
|
Nandula A, Trinh QT, Saeys M, Alexandrova AN. Origin of Extraordinary Stability of Square-Planar Carbon Atoms in Surface Carbides of Cobalt and Nickel. Angew Chem Int Ed Engl 2015; 54:5312-6. [DOI: 10.1002/anie.201501049] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Indexed: 11/12/2022]
|
12
|
Nandula A, Trinh QT, Saeys M, Alexandrova AN. Origin of Extraordinary Stability of Square-Planar Carbon Atoms in Surface Carbides of Cobalt and Nickel. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201501049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
13
|
Wu YB, Li YQ, Bai H, Lu HG, Li SD, Zhai HJ, Wang ZX. D(3h) [A-CE3-A]⁻ (E = Al and Ga, A = Si, Ge, Sn, and Pb): a new class of hexatomic mono-anionic species with trigonal bipyramidal carbon. J Chem Phys 2014; 140:104302. [PMID: 24628164 DOI: 10.1063/1.4867364] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The non-classical trigonal bipyramidal carbon (TBPC) arrangement generally exists as transition states (TSs) in nucleophilic bimolecular substitution (S(N)2) reactions. Nevertheless, chemists have been curious about whether such a carbon bonding could be stable in equilibrium structures for decades. As the TBPC arrangement was normally realized as cationic species theoretically and experimentally, only one anionic example ([At-C(CN)3-At](-)) was computationally devised. Herein, we report the design of a new class of anionic TBPC species by using the strategy similar to that for stabilizing the non-classical planar hypercoordinate carbon. When electron deficient Al and Ga were used as the equatorial ligands, eight D(3h) [A-CE3-A](-) (E = Al and Ga, A = Si, Ge, Sn, and Pb) TBPC structures were found to be the energy minima rather than TSs at both the B3LYP and MP2 levels. Remarkably, the energetic results at the CCSD(T) optimization level further identify [Ge-CAl3-Ge](-) and [Sn-CGa3-Sn](-) even to be the global minima and [Si-CAl3-Si](-) and [Ge-CGa3-Ge](-) to be the local minima, only slightly higher than their global minima. The electronic structure analyses reveal that the substantial ionic C-E bonding, the peripheral E-A covalent bonding, and the axial mc-2e (multi center-two electrons) bonding play roles in stabilizing these TBPC structures. The structural simplicity and the high thermodynamic stability suggest that some of these species may be generated and captured in the gas phase. Furthermore, as mono-anionic species, their first vertical detachment energies are differentiable from those of their nearest isomers, which would facilitate their characterization via experiments such as the negative ion photoelectron spectroscopy.
Collapse
Affiliation(s)
- Yan-Bo Wu
- Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Wucheng Road 92#, Taiyuan 030006, People's Republic of China
| | - Yan-Qin Li
- Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Wucheng Road 92#, Taiyuan 030006, People's Republic of China
| | - Hui Bai
- Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Wucheng Road 92#, Taiyuan 030006, People's Republic of China
| | - Hai-Gang Lu
- Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Wucheng Road 92#, Taiyuan 030006, People's Republic of China
| | - Si-Dian Li
- Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Wucheng Road 92#, Taiyuan 030006, People's Republic of China
| | - Hua-Jin Zhai
- Institute of Molecular Science, Key Laboratory of Chemical Biology and Molecular Engineering of Education Ministry, Shanxi University, Wucheng Road 92#, Taiyuan 030006, People's Republic of China
| | - Zhi-Xiang Wang
- College of Chemistry and Chemical Engineering, University of Chinese Academy of Sciences, Yuquan Road 19#, Beijing 100049, People's Republic of China
| |
Collapse
|
14
|
Alikhani ME. On the chemical bonding features in boron containing compounds: a combined QTAIM/ELF topological analysis. Phys Chem Chem Phys 2013; 15:12602-9. [DOI: 10.1039/c3cp50396h] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
15
|
Alexandrova AN, Nayhouse MJ, Huynh MT, Kuo JL, Melkonian AV, Chavez G, Hernando NM, Kowal MD, Liu CP. Selected AB4(2-/-) (A = C, Si, Ge; B = Al, Ga, In) ions: a battle between covalency and aromaticity, and prediction of square planar Si in SiIn4(2-/-). Phys Chem Chem Phys 2012; 14:14815-21. [PMID: 22868353 PMCID: PMC3478443 DOI: 10.1039/c2cp41821e] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
CAl(4)(2-/-) (D(4h), (1)A(1g)) is a cluster ion that has been established to be planar, aromatic, and contain a tetracoordinate planar C atom. Valence isoelectronic substitution of C with Si and Ge in this cluster leads to a radical change of structure toward distorted pentagonal species. We find that this structural change goes together with the cluster acquiring partial covalency of bonding between Si/Ge and Al(4), facilitated by hybridization of the atomic orbitals (AOs). Counter intuitively, for the AAl(4)(2-/-) (A = C, Si, Ge) clusters, hybridization in the dopant atom is strengthened from C, to Si, and to Ge, even though typically AOs are more likely to hybridize if they are closer in energy (i.e. in earlier elements in the Periodic Table). The trend is explained by the better overlap of the hybrids of the heavier dopants with the orbitals of Al(4). From the thus understood trend, it is inferred that covalency in such clusters can be switched off, by varying the relative sizes of the AOs of the main element and the dopant. Using this mechanism, we then successfully killed covalency in Si, and predicted a new aromatic cluster ion containing a tetracoordinate square planar Si, SiIn(4)(2-/-).
Collapse
Affiliation(s)
- Anastassia N Alexandrova
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Braunschweig H, Dewhurst RD, Kraft K, Östreicher S, Radacki K. Ein planar vierfach koordiniertes Boratom als Ligand für vier Metalle. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201107248] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
17
|
Braunschweig H, Dewhurst RD, Kraft K, Östreicher S, Radacki K. Planar Four-Coordinate Boron: A Single, Flat Boron Atom as a Ligand for Four Metals. Angew Chem Int Ed Engl 2012; 51:2183-6. [DOI: 10.1002/anie.201107248] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2011] [Indexed: 11/09/2022]
|
18
|
Lithiation-Based and Magnesation-Based Strategies for the Functionalization of Imidazole: 2001–2010. TOPICS IN HETEROCYCLIC CHEMISTRY 2012. [DOI: 10.1007/7081_2012_73] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
|
19
|
Crigger C, Wittmaack BK, Tawfik M, Merino G, Donald KJ. Plane and simple: planar tetracoordinate carbon centers in small molecules. Phys Chem Chem Phys 2012; 14:14775-83. [DOI: 10.1039/c2cp41986f] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
20
|
MB 8 2− (M = Be, Mg, Ca, Sr, and Ba): Planar octacoordinate alkaline earth metal atoms enclosed by boron rings. Sci China Chem 2010. [DOI: 10.1007/s11426-010-4037-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
21
|
Zhang C, Jia W, Cao Z. Stability Rules of Main-Group Element Compounds with Planar Tetracoordinate Carbons. J Phys Chem A 2010; 114:7960-6. [DOI: 10.1021/jp102678v] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Congjie Zhang
- Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Materials Science, Shaanxi Normal University, Xi’an 710062, China, and Department of Chemistry and State Key Laboratory of Physical Chemistry of Solid Surface, Xiamen University, Xiamen 361005, China
| | - Wenhong Jia
- Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Materials Science, Shaanxi Normal University, Xi’an 710062, China, and Department of Chemistry and State Key Laboratory of Physical Chemistry of Solid Surface, Xiamen University, Xiamen 361005, China
| | - Zexing Cao
- Key Laboratory of Macromolecular Science of Shaanxi Province, School of Chemistry & Materials Science, Shaanxi Normal University, Xi’an 710062, China, and Department of Chemistry and State Key Laboratory of Physical Chemistry of Solid Surface, Xiamen University, Xiamen 361005, China
| |
Collapse
|
22
|
Zhang C, Wang P, Liang J, Jia W, Cao Z. Theoretical study on a family of organic molecules with planar tetracoordinate carbon. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.theochem.2009.10.036] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
23
|
Yu HL, Sang RL, Wu YY. Structure and Aromaticity of B6H5+ Cation: A Novel Borhydride System Containing Planar Pentacoordinated Boron. J Phys Chem A 2009; 113:3382-6. [DOI: 10.1021/jp809599z] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Hong-Lang Yu
- Department of Chemistry, Hanshan Normal University, Chaozhou,Guangdong, 521041, Poeple’s Republic of China, State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, People’s Republic of China
| | - Rui-Li Sang
- Department of Chemistry, Hanshan Normal University, Chaozhou,Guangdong, 521041, Poeple’s Republic of China, State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, People’s Republic of China
| | - Yun-Ying Wu
- Department of Chemistry, Hanshan Normal University, Chaozhou,Guangdong, 521041, Poeple’s Republic of China, State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian, 350002, People’s Republic of China
| |
Collapse
|
24
|
CSi2Ga2: a neutral planar tetracoordinate carbon (ptC) building block. J Mol Model 2008; 15:97-104. [DOI: 10.1007/s00894-008-0362-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2008] [Accepted: 09/22/2008] [Indexed: 11/27/2022]
|
25
|
Boron rings containing planar octa-and enneacoordinate cobalt, iron and nickel metal elements. ACTA ACUST UNITED AC 2008. [DOI: 10.1007/s11426-008-0073-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
|
26
|
Pei Y, Zeng XC. Probing the Planar Tetra-, Penta-, and Hexacoordinate Carbon in Carbon−Boron Mixed Clusters. J Am Chem Soc 2008; 130:2580-92. [DOI: 10.1021/ja077139v] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Yong Pei
- Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| | - Xiao Cheng Zeng
- Department of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, Nebraska 68588
| |
Collapse
|
27
|
Islas R, Heine T, Ito K, Schleyer PVR, Merino G. Boron Rings Enclosing Planar Hypercoordinate Group 14 Elements. J Am Chem Soc 2007; 129:14767-74. [DOI: 10.1021/ja074956m] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Rafael Islas
- Contribution from the Facultad de Química, Universidad de Guanajuato. Col. Noria Alta s/n C.P. 36050, Guanajuato, Gto., México, Physikalische Chemie, Fachbereich Chemie, TU Dresden, D-01062 Dresden, Germany, Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602-2525
| | - Thomas Heine
- Contribution from the Facultad de Química, Universidad de Guanajuato. Col. Noria Alta s/n C.P. 36050, Guanajuato, Gto., México, Physikalische Chemie, Fachbereich Chemie, TU Dresden, D-01062 Dresden, Germany, Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602-2525
| | - Keigo Ito
- Contribution from the Facultad de Química, Universidad de Guanajuato. Col. Noria Alta s/n C.P. 36050, Guanajuato, Gto., México, Physikalische Chemie, Fachbereich Chemie, TU Dresden, D-01062 Dresden, Germany, Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602-2525
| | - Paul v. R. Schleyer
- Contribution from the Facultad de Química, Universidad de Guanajuato. Col. Noria Alta s/n C.P. 36050, Guanajuato, Gto., México, Physikalische Chemie, Fachbereich Chemie, TU Dresden, D-01062 Dresden, Germany, Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602-2525
| | - Gabriel Merino
- Contribution from the Facultad de Química, Universidad de Guanajuato. Col. Noria Alta s/n C.P. 36050, Guanajuato, Gto., México, Physikalische Chemie, Fachbereich Chemie, TU Dresden, D-01062 Dresden, Germany, Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602-2525
| |
Collapse
|
28
|
Yang LM, Ding YH, Sun CC. The Si-doped planar tetracoordinate carbon (ptC) unit CAl3Si− could be used as a building block or inorganic ligand during cluster-assembly. Theor Chem Acc 2007. [DOI: 10.1007/s00214-007-0389-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
29
|
Pratt LM, Truhlar DG, Cramer CJ, Kass SR, Thompson JD, Xidos JD. Aggregation of Alkyllithiums in Tetrahydrofuran. J Org Chem 2007; 72:2962-6. [PMID: 17358078 DOI: 10.1021/jo062557o] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Density functional theory was used to examine the solvation number and aggregation state of several alkyllithium compounds in clusters with tetrahydrofuran molecules coordinated to each lithium atom. We then made the microsolvation approximation and approximated the bulk free energy of solvation by the free energy of clustering with solvent molecules in the gas phase. The trends in the computed results are in reasonable agreement with the available experimental data.
Collapse
Affiliation(s)
- Lawrence M Pratt
- Department of Chemistry, Fisk University, Nashville, Tennessee 37208, USA.
| | | | | | | | | | | |
Collapse
|
30
|
Doherty WJ, Friedlein R, Renouard T, Mathis C, Salaneck WR. Electronic structure of Li-intercalated oligopyridines: A comparative study by photoelectron spectroscopy. J Chem Phys 2007; 126:094708. [PMID: 17362119 DOI: 10.1063/1.2710262] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The role of nitrogen in the charge transfer and storage capacity of lithium-intercalated heterocyclic oligophenylenes was investigated using photoelectron spectroscopy. The development of new occupied states at low binding energies in the valence band region, as well as core level chemical shifts at both carbon and nitrogen sites, demonstrates partial charge transfer from lithium atoms to the organic component during formation of the intercalated compound. In small compounds, i.e., biphenyl and bipyridine derivatives, the position of the nitrogen heteroatom significantly affects the spacing between gap states in the Li-intercalated film; yet it has minimal effects on the charge storage capacity. In larger, branched systems, the presence of nitrogen in the aromatic system significantly enhances the charge storage capacity while the Li-N bond strength at high intercalation levels is significantly weakened relative to the nitrogen-free derivative. These observations have strong implications towards improved deintercalation processes in organic electrodes in lithium-ion batteries.
Collapse
Affiliation(s)
- Walter J Doherty
- Department of Physics, Chemistry, and Biology (IFM), Linköping University, 581 83 Linköping, Sweden.
| | | | | | | | | |
Collapse
|
31
|
Yang LM, Ding YH, Tian WQ, Sun CC. Planar carbon radical’s assembly and stabilization, a way to design spin-based molecular materials. Phys Chem Chem Phys 2007; 9:5304-14. [PMID: 17914465 DOI: 10.1039/b707898f] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In this work, we report the first computational study on the assembly and stabilization of a novel kind of radical, i.e., the planar tetracoordinate carbon radical CAl(4)(-). Based on the 6-31+G(d)-UB3LYP, UMP2 and UCCSD(T) calculations on charged [D(CAl(4))M](q-), saturated [D(CAl(4))M(n)] and extended (CpM)(p)(CAl(4))(q) sandwich-like compounds (D = CAl(4)(-), Cp(-); M = Li, Na, K, Be, Mg, Ca), we find that for the six metals, the planar radical CAl(4)(-) can only be assembled in the "hetero-decked sandwich" scheme (e.g. [CpM(CAl(4))](q-)) rather than the traditional "homo-decked sandwich" scheme. Moreover, the low and high spin states of the designed sandwich-like species are perfectly degenerate during assembly. This can be ascribed to the good spin conservation of the CAl(4)(-) deck and the good spatial separation between two CAl(4)(-) decks. Our results show for the first time that the planar radical CAl(4)(-) can act as a new type of spin-embedded "superatom" for cluster assembly when it is assisted by a rigid partner like Cp(-). The good spin-conservation of CAl(4)(-) is very promising for the future design of novel paramagnetic and diamagnetic materials. The ionic, clustering and radical interactions between the two decks are analyzed in detail, which is quite crucial to improve the insight and understanding of the nature and origin of the interactions of the "deck-core-deck" in the metallocenes. Such information is also important in understanding the radical reactions and designing novel spin-based molecular materials. The present study should be expected to enrich the flat carbon chemistry, radical chemistry, metallocene chemistry and combinatorial chemistry.
Collapse
Affiliation(s)
- Li-Ming Yang
- State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun, 130023, People's Republic of China
| | | | | | | |
Collapse
|
32
|
Yang LM, Ding YH, Sun CC. Design of Sandwichlike Complexes Based on the Planar Tetracoordinate Carbon Unit CAl42-. J Am Chem Soc 2006; 129:658-65. [PMID: 17227029 DOI: 10.1021/ja066217w] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Ever being a large curiosity, a series of simple "planar tetracoordinate carbon (ptC)" molecules have been recently characterized by experiments. Incorporation of such exotic ptC units into the assembled molecular materials, which will bridge the isolated clusters in molecular beams and the potential solid materials, is very challenging. In this paper, we described the first attempt on how to assemble the fewest-number ptC unit CAl42- into molecular materials in sandwich forms on the basis of the density functional theory calculations on a series of model compounds [D(CAl4)M]q- as well as the saturated compounds [D(CAl4)Mn] ((D = CAl42-, Cp-(C5H5-); M = Li, Na, K, Be, Mg, Ca). For M = Li, Be, Mg, and Ca, the ptC unit CAl42- can only be assembled in our newly proposed "heterodecked sandwich" scheme (e.g., [Cp(CAl4)M]q- (M = Li, Na, K, q = 2; M = Be, Mg, Ca, q = 1)) so as to avoid cluster fusion. For M = Na and K, the ptC unit CAl42- can be assembled in both the traditional "homodecked sandwich" [(CAl4)2M]q- (M = Li, Na, K, q = 3; M = Be, Mg, Ca, q = 2) and the novel heterodecked sandwich schemes. Moreover, the counterions were found to have an important role in determining the type of the ground structures for the homodecked sandwich. Various assembled species in extended frameworks were designed. Notably, among all the designed sandwich species, the ptC unit CAl42- generally prefers to interact with the partner deck at the side (Al-Al bond) or corner (Al atom) site. This has not been reported in the sandwich complexes on the basis of the known decks such as Cp-, P5-, N42-, and Al42-, for which only the traditional face-face interaction type was considered. Our results for the first time showed that the ptC unit CAl42- can act as a new type of "superatom". The present results are expected to enrich the flat carbon chemistry, superatom chemistry, metallocenes, and combinational chemistry.
Collapse
Affiliation(s)
- Li-Ming Yang
- Contribution from the State Key Laboratory of Theoretical and Computational Chemistry, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, People's Republic of China
| | | | | |
Collapse
|
33
|
Ohno K, Maeda S. Global Reaction Route Mapping on Potential Energy Surfaces of Formaldehyde, Formic Acid, and Their Metal-Substituted Analogues. J Phys Chem A 2006; 110:8933-41. [PMID: 16836457 DOI: 10.1021/jp061149l] [Citation(s) in RCA: 248] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Global reaction route mapping of equilibrium structures, transition structures, and their connections on potential energy surface (PES) has been done for MCHO (M = H, Li, Na, Al, Cu) and HCO2M (M = H, Li). A one-after-another technique based on the scaled hypersphere search method has been successfully applied to exploring unknown chemical structures, transition structures, and reaction pathways for organometallic systems. Upon metal substitution, considerable changes of stable structures, reaction pathways, and relative heights of transition structures have been discovered, though some features are similar among the analogues. Al and Cu atoms were found to behave as very strong scissors to cut the CO double bond in MCHO. Energy profiles of the CO insertion into Li-H and Li-CH3 bonds were found to be very similar, especially around the structures where the Li atom is not directly connected with the methyl group, which indicates little effects of alkyl substitution on the reaction route topology.
Collapse
Affiliation(s)
- Koichi Ohno
- Department of Chemistry, Graduate School of Science, Tohoku University, Aramaki, Sendai 980-8578, Japan.
| | | |
Collapse
|
34
|
Merino G, Méndez-Rojas MA, Vela A, Heine T. Recent advances in planar tetracoordinate carbon chemistry. J Comput Chem 2006; 28:362-72. [PMID: 17143864 DOI: 10.1002/jcc.20515] [Citation(s) in RCA: 179] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We summarize our contributions on the quest of new planar tetracoordinate carbon entities (new carbon molecules with exotic chemical structures and strange bonding schemes). We give special emphasis on the rationalization why in this type of molecules the planar configuration is favored over the tetrahedral one. We will concentrate on the latter and will show that molecules containing planar tetracoordinate carbons have a stabilizing system of delocalized pi electrons, which shows similar properties as pi systems in aromatic molecules.
Collapse
Affiliation(s)
- Gabriel Merino
- Facultad de Química, Universidad de Guanajuato, Col. Noria Alta s/n, CP 36050, Guanajuato, Gto., México.
| | | | | | | |
Collapse
|
35
|
Sateesh B, Srinivas Reddy A, Narahari Sastry G. Towards design of the smallest planar tetracoordinate carbon and boron systems. J Comput Chem 2006; 28:335-43. [PMID: 17103398 DOI: 10.1002/jcc.20552] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A series of cyclic hydrocarbons analogs where a carbon displays unusual planar tetracoordinate structure is proposed, employing hybrid density functional theory calculations using B3LYP functional and 6-311+G** basis set. Various strategies were employed to design the neutral planar tetracoordinate hydrocarbon analogs. The same strategy is employed for designing the planar tetracoordinate boron systems. The simplest neutral planar tetracoordinate hydrocarbons were proposed and the effect of substitution on their stability has been assessed. The aromatic stabilization is gauged with nucleus independent chemical shift calculations. The activation barriers for the ring opening reaction, the highest occupied molecular orbital and lowest unoccupied molecular orbitals gap and singlet-triplet energy difference were estimated to gauge the plausibility experimental realization.
Collapse
Affiliation(s)
- B Sateesh
- Molecular Modeling Group, Indian Institute of Chemical Technology, Tarnaka, Hyderabad 500 007, India
| | | | | |
Collapse
|
36
|
Perez N, Heine T, Barthel R, Seifert G, Vela A, Mendez-Rojas MA, Merino G. Planar Tetracoordinate Carbons in Cyclic Hydrocarbons. Org Lett 2005; 7:1509-12. [PMID: 15816739 DOI: 10.1021/ol050170m] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
[structure: see text] A series of cyclic hydrocarbons containing a planar tetracoordinate carbon atom is proposed. To rationalize the electronic factors contributing to the stability of these molecules, an analysis of the molecular orbitals and the induced magnetic field is presented.
Collapse
Affiliation(s)
- Nancy Perez
- Departamento de Química y Biología, Universidad de las Américas-Puebla, Ex-Hda. de Sta. Catarina Mártir, A. P. 100, Cholula 72820, Puebla, México
| | | | | | | | | | | | | |
Collapse
|
37
|
Pratt LM, Mogali S, Glinton K. Solvent effects on the aggregation state of lithium dialkylaminoborohydrides. J Org Chem 2003; 68:6484-8. [PMID: 12919007 DOI: 10.1021/jo034498+] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
DFT calculations were performed to determine the effects of ethereal solvents on the aggregation state of lithium dialkylaminoborohydrides (LABs). The calculations included dimerization energies in the gas phase, with continuum solvation only, microsolvation with coordinating ethereal ligands, and a combination of the microsolvation and continuum models. The continuum model alone overestimates the stability of the dimers, apparently due to the lack of steric effects from the coordinating ethereal ligands. The use of the combined microsolvation and continuum solvation models predicts lithium dimethylaminoborohydride to be a mixture of monomer and dimer in THF, and more sterically hindered lithium aminoborohydrides to exist primarily as monomers. The kinetics of amination of 1-chlorodecane by lithium dimethylaminoborohydride showed no detectable change in reaction rate with time, suggesting that the LAB reagent may exist primarily as a monomer in THF.
Collapse
Affiliation(s)
- Lawrence M Pratt
- Department of Chemistry, Fisk University, 1000 17th Avenue North, Nashville, Tennessee 37208, USA.
| | | | | |
Collapse
|