Theoretical Studies of Organometallic Compounds. 9. Structures and Bond Energies of the Methylcuprates CH3Cu, (CH3)2Cu−, (CH3)2CuLi,(CH3)2CuLi.·H2O,[(CH3)2CuLi]2, and [(CH3)2CuLi]2·2H2O

Marlis Böhme; Gernot Frenking; Manfred T. Reetz

doi:10.1021/om00023a029

Theoretical Studies of Organometallic Compounds. 9. Structures and Bond Energies of the Methylcuprates CH₃Cu, (CH₃)₂Cu⁻, (CH₃)₂CuLi,(CH₃)₂CuLi.·H₂O,[(CH₃)₂CuLi]₂, and [(CH₃)₂CuLi]₂·2H₂O

Marlis Böhme, Gernot Frenking, Manfred T. Reetz

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Abstract

The geometries of the copper compounds CH₃Cu (1), (CH₃)₂Cu⁻ (2), (CH₃)₂CuLi (3), (CH₃)₂CuLi·H₂O (4), [(CH₃)₂CuLi]₂ (5), and [(CH₃)₂CuLi]₂·2H₂O (6) are optimized at the HF and MP2 level of theory, using an effective core potential for Cu and all-electron basis sets for the other atoms. The Cu—C bond strength is calculated at correlated levels, and the electronic structure of 1–6 is investigated using the topological analysis of the electron density distribution and the natural bond orbital partitioning scheme. The optimized geometries at the MP2 level appear to be reliable, while the HF optimized structures have Cu—C bond lengths which are too long. Methylcopper (1) is predicted with a Cu—C bond length of 1.923 Å and a Cu—C bond strength D₀ = 45. 0 kcal/mol. Dimethylcuprate anion (2) has a linear (D_3h) structure and slightly longer Cu—C bond distances (1.963 Å) than 1. The global energy minimum structure of the monomeric form of Gilman's reagent (CH₃)₂-CuLi (3d) is predicted with an open (noncyclic) geometry and a nearly linear CH₃—Cu—CH₃ moiety. The lithium atom in 3d is coordinated to only one methyl group. The cyclic forms with a bridging lithium atom are no energy minima on the potential energy hypersurface at the MP₂ level of theory. Complexation of 3 by one water molecule at Li does not influence the geometries and relative energies of the open and cyclic forms. The global energy minimum structure of (CH₃)₂CuLi·H₂O (4) is 4d, which has an open (noncyclic) geometry with a nearly linear CH3—Cu—CH3 moiety. The dimeric form of Gilman's reagent [(CH₃)₂-CuLi]₂ (5) has a planar cyclic geometry with D_2h symmetry. Complexation of 5 at the lithium atoms by two water molecules gives [(CH₃)₂CuLi]₂·2H₂O (6). The geometry optimization of 6 yields two energetically nearly degenerate forms 6a,b with slightly twisted geometries which deviate only little from D₂h symmetry. The analysis of the electronic structure shows that the Cu—C bonds in 1-6 are strongly polarized toward the carbon atom. The polar Cu—C bonds have distinct covalent contributions, however. The copper bonding has mainly s-character (~90%) as revealed by the NBO analysis.

Original language	English
Pages (from-to)	4237-4245
Number of pages	9
Journal	Organometallics
Volume	13
Issue number	11
DOIs	https://doi.org/10.1021/om00023a029
State	Published - 1 Nov 1994
Externally published	Yes

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@article{1aae91b471d6452ab4aaf2781e886bba,

title = "Theoretical Studies of Organometallic Compounds. 9. Structures and Bond Energies of the Methylcuprates CH3Cu, (CH3)2Cu−, (CH3)2CuLi,(CH3)2CuLi.·H2O,[(CH3)2CuLi]2, and [(CH3)2CuLi]2·2H2O",

abstract = "The geometries of the copper compounds CH3Cu (1), (CH3)2Cu− (2), (CH3)2CuLi (3), (CH3)2CuLi·H2O (4), [(CH3)2CuLi]2 (5), and [(CH3)2CuLi]2·2H2O (6) are optimized at the HF and MP2 level of theory, using an effective core potential for Cu and all-electron basis sets for the other atoms. The Cu—C bond strength is calculated at correlated levels, and the electronic structure of 1–6 is investigated using the topological analysis of the electron density distribution and the natural bond orbital partitioning scheme. The optimized geometries at the MP2 level appear to be reliable, while the HF optimized structures have Cu—C bond lengths which are too long. Methylcopper (1) is predicted with a Cu—C bond length of 1.923 {\AA} and a Cu—C bond strength D0 = 45. 0 kcal/mol. Dimethylcuprate anion (2) has a linear (D3h) structure and slightly longer Cu—C bond distances (1.963 {\AA}) than 1. The global energy minimum structure of the monomeric form of Gilman's reagent (CH3)2-CuLi (3d) is predicted with an open (noncyclic) geometry and a nearly linear CH3—Cu—CH3 moiety. The lithium atom in 3d is coordinated to only one methyl group. The cyclic forms with a bridging lithium atom are no energy minima on the potential energy hypersurface at the MP2 level of theory. Complexation of 3 by one water molecule at Li does not influence the geometries and relative energies of the open and cyclic forms. The global energy minimum structure of (CH3)2CuLi·H2O (4) is 4d, which has an open (noncyclic) geometry with a nearly linear CH3—Cu—CH3 moiety. The dimeric form of Gilman's reagent [(CH3)2-CuLi]2 (5) has a planar cyclic geometry with D2h symmetry. Complexation of 5 at the lithium atoms by two water molecules gives [(CH3)2CuLi]2·2H2O (6). The geometry optimization of 6 yields two energetically nearly degenerate forms 6a,b with slightly twisted geometries which deviate only little from D2h symmetry. The analysis of the electronic structure shows that the Cu—C bonds in 1-6 are strongly polarized toward the carbon atom. The polar Cu—C bonds have distinct covalent contributions, however. The copper bonding has mainly s-character (~90%) as revealed by the NBO analysis.",

author = "Marlis B{\"o}hme and Gernot Frenking and Reetz, {Manfred T.}",

year = "1994",

month = nov,

day = "1",

doi = "10.1021/om00023a029",

language = "英语",

volume = "13",

pages = "4237--4245",

journal = "Organometallics",

issn = "0276-7333",

publisher = "American Chemical Society",

number = "11",

}

Theoretical Studies of Organometallic Compounds. 9. Structures and Bond Energies of the Methylcuprates CH₃Cu, (CH₃)₂Cu⁻, (CH₃)₂CuLi,(CH₃)₂CuLi.·H₂O,[(CH₃)₂CuLi]₂, and [(CH₃)₂CuLi]₂·2H₂O. / Böhme, Marlis; Frenking, Gernot; Reetz, Manfred T.
In: Organometallics, Vol. 13, No. 11, 01.11.1994, p. 4237-4245.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - Theoretical Studies of Organometallic Compounds. 9. Structures and Bond Energies of the Methylcuprates CH3Cu, (CH3)2Cu−, (CH3)2CuLi,(CH3)2CuLi.·H2O,[(CH3)2CuLi]2, and [(CH3)2CuLi]2·2H2O

AU - Böhme, Marlis

AU - Frenking, Gernot

AU - Reetz, Manfred T.

PY - 1994/11/1

Y1 - 1994/11/1

N2 - The geometries of the copper compounds CH3Cu (1), (CH3)2Cu− (2), (CH3)2CuLi (3), (CH3)2CuLi·H2O (4), [(CH3)2CuLi]2 (5), and [(CH3)2CuLi]2·2H2O (6) are optimized at the HF and MP2 level of theory, using an effective core potential for Cu and all-electron basis sets for the other atoms. The Cu—C bond strength is calculated at correlated levels, and the electronic structure of 1–6 is investigated using the topological analysis of the electron density distribution and the natural bond orbital partitioning scheme. The optimized geometries at the MP2 level appear to be reliable, while the HF optimized structures have Cu—C bond lengths which are too long. Methylcopper (1) is predicted with a Cu—C bond length of 1.923 Å and a Cu—C bond strength D0 = 45. 0 kcal/mol. Dimethylcuprate anion (2) has a linear (D3h) structure and slightly longer Cu—C bond distances (1.963 Å) than 1. The global energy minimum structure of the monomeric form of Gilman's reagent (CH3)2-CuLi (3d) is predicted with an open (noncyclic) geometry and a nearly linear CH3—Cu—CH3 moiety. The lithium atom in 3d is coordinated to only one methyl group. The cyclic forms with a bridging lithium atom are no energy minima on the potential energy hypersurface at the MP2 level of theory. Complexation of 3 by one water molecule at Li does not influence the geometries and relative energies of the open and cyclic forms. The global energy minimum structure of (CH3)2CuLi·H2O (4) is 4d, which has an open (noncyclic) geometry with a nearly linear CH3—Cu—CH3 moiety. The dimeric form of Gilman's reagent [(CH3)2-CuLi]2 (5) has a planar cyclic geometry with D2h symmetry. Complexation of 5 at the lithium atoms by two water molecules gives [(CH3)2CuLi]2·2H2O (6). The geometry optimization of 6 yields two energetically nearly degenerate forms 6a,b with slightly twisted geometries which deviate only little from D2h symmetry. The analysis of the electronic structure shows that the Cu—C bonds in 1-6 are strongly polarized toward the carbon atom. The polar Cu—C bonds have distinct covalent contributions, however. The copper bonding has mainly s-character (~90%) as revealed by the NBO analysis.

AB - The geometries of the copper compounds CH3Cu (1), (CH3)2Cu− (2), (CH3)2CuLi (3), (CH3)2CuLi·H2O (4), [(CH3)2CuLi]2 (5), and [(CH3)2CuLi]2·2H2O (6) are optimized at the HF and MP2 level of theory, using an effective core potential for Cu and all-electron basis sets for the other atoms. The Cu—C bond strength is calculated at correlated levels, and the electronic structure of 1–6 is investigated using the topological analysis of the electron density distribution and the natural bond orbital partitioning scheme. The optimized geometries at the MP2 level appear to be reliable, while the HF optimized structures have Cu—C bond lengths which are too long. Methylcopper (1) is predicted with a Cu—C bond length of 1.923 Å and a Cu—C bond strength D0 = 45. 0 kcal/mol. Dimethylcuprate anion (2) has a linear (D3h) structure and slightly longer Cu—C bond distances (1.963 Å) than 1. The global energy minimum structure of the monomeric form of Gilman's reagent (CH3)2-CuLi (3d) is predicted with an open (noncyclic) geometry and a nearly linear CH3—Cu—CH3 moiety. The lithium atom in 3d is coordinated to only one methyl group. The cyclic forms with a bridging lithium atom are no energy minima on the potential energy hypersurface at the MP2 level of theory. Complexation of 3 by one water molecule at Li does not influence the geometries and relative energies of the open and cyclic forms. The global energy minimum structure of (CH3)2CuLi·H2O (4) is 4d, which has an open (noncyclic) geometry with a nearly linear CH3—Cu—CH3 moiety. The dimeric form of Gilman's reagent [(CH3)2-CuLi]2 (5) has a planar cyclic geometry with D2h symmetry. Complexation of 5 at the lithium atoms by two water molecules gives [(CH3)2CuLi]2·2H2O (6). The geometry optimization of 6 yields two energetically nearly degenerate forms 6a,b with slightly twisted geometries which deviate only little from D2h symmetry. The analysis of the electronic structure shows that the Cu—C bonds in 1-6 are strongly polarized toward the carbon atom. The polar Cu—C bonds have distinct covalent contributions, however. The copper bonding has mainly s-character (~90%) as revealed by the NBO analysis.

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U2 - 10.1021/om00023a029

DO - 10.1021/om00023a029

M3 - 文章

AN - SCOPUS:0000207224

SN - 0276-7333

VL - 13

SP - 4237

EP - 4245

JO - Organometallics

JF - Organometallics

IS - 11

ER -

Theoretical Studies of Organometallic Compounds. 9. Structures and Bond Energies of the Methylcuprates CH₃Cu, (CH₃)₂Cu⁻, (CH₃)₂CuLi,(CH₃)₂CuLi.·H₂O,[(CH₃)₂CuLi]₂, and [(CH₃)₂CuLi]₂·2H₂O

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