Chromium−Chromium Multiple Bonding in Cr2(CO)9

Se Li; Nancy A. Richardson; R Bruce King; Henry F Schaefer

doi:10.1021/jp030804b

Chromium−Chromium Multiple Bonding in Cr2(CO)9

Se Li, Nancy A. Richardson, R Bruce King, Henry F Schaefer

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

Abstract

<div class="line" id="line-7"> Density functional theory (DFT) is used to obtain the first structural characterization of the unsaturated dichromium carbonyl Cr 2 (CO) 9 , which is predicted to have a remarkably short metal−metal bond length of 2.31 Å (B3LYP) or 2.28 Å (BP86). This chromium−chromium distance is essentially identical to that reported experimentally for the established Cr&vellip;Cr triple bond in (η 5 -Me 5 C 5 ) 2 Cr 2 (CO) 4 . The dissociation energy to the fragments Cr(CO) 4  and Cr(CO) 5  is determined to be 32 kcal/mol (B3LYP) or 43 kcal/mol (BP86). For comparison, the Cr 2 (CO) 10  molecule and the saturated Cr 2 (CO) 11  system have negligible dissociation energies. The minimum energy Cr 2 (CO) 9  structure is of  C s  symmetry with the two chromium atoms asymmetrically bonded to the bridging carbonyls. However, within 0.1 kcal/mol lies a  C 2  symmetry structure with one symmetric and two asymmetric bridging carbonyls. Furthermore, the high symmetry  D 3 h  structure analogous to Fe 2 (CO) 9  lies only &sim;1 kcal/mol higher in energy. The Cr 2 (CO) 9  molecule is thus highly fluxional. The extremely flat potential energy surface in the region adjacent to these minima suggests that Cr 2 (CO) 9  will be labile. The relationship between the Cr 2 (CO) 9  molecule and the experimentally known binuclear manganese (η 5 -Me 5 C 5 ) 2 Mn 2 (μ-CO) 3  compound is explored.</div>

Original language	American English
Journal	The Journal of Physical Chemistry A
Volume	107
DOIs	https://doi.org/10.1021/jp030804b
State	Published - Oct 2003

Keywords

Group theory
Chromium
Chemical structure
Carbonyls Transition metals

Disciplines

Physical Sciences and Mathematics
Chemistry

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@article{f2f73b2fd2a645889fd640324a6652fa,

title = "Chromium−Chromium Multiple Bonding in Cr2(CO)9",

abstract = " Density functional theory (DFT) is used to obtain the first structural characterization of the unsaturated dichromium carbonyl Cr 2 (CO) 9 , which is predicted to have a remarkably short metal−metal bond length of 2.31 Å (B3LYP) or 2.28 Å (BP86). This chromium−chromium distance is essentially identical to that reported experimentally for the established Cr&vellip;Cr triple bond in (η 5 -Me 5 C 5 ) 2 Cr 2 (CO) 4 . The dissociation energy to the fragments Cr(CO) 4  and Cr(CO) 5  is determined to be 32 kcal/mol (B3LYP) or 43 kcal/mol (BP86). For comparison, the Cr 2 (CO) 10  molecule and the saturated Cr 2 (CO) 11  system have negligible dissociation energies. The minimum energy Cr 2 (CO) 9  structure is of  C s  symmetry with the two chromium atoms asymmetrically bonded to the bridging carbonyls. However, within 0.1 kcal/mol lies a  C 2  symmetry structure with one symmetric and two asymmetric bridging carbonyls. Furthermore, the high symmetry  D 3 h  structure analogous to Fe 2 (CO) 9  lies only &sim;1 kcal/mol higher in energy. The Cr 2 (CO) 9  molecule is thus highly fluxional. The extremely flat potential energy surface in the region adjacent to these minima suggests that Cr 2 (CO) 9  will be labile. The relationship between the Cr 2 (CO) 9  molecule and the experimentally known binuclear manganese (η 5 -Me 5 C 5 ) 2 Mn 2 (μ-CO) 3  compound is explored.",

keywords = "Group theory, Chromium, Chemical structure, Carbonyls Transition metals",

author = "Se Li and Richardson, {Nancy A.} and King, {R Bruce} and Schaefer, {Henry F}",

note = "Density functional theory (DFT) is used to obtain the first structural characterization of the unsaturated dichromium carbonyl Cr2(CO)9, which is predicted to have a remarkably short metal−metal bond length of 2.31 {\AA} (B3LYP) or 2.28 {\AA} (BP86). This chromium−chromium distance is essentially identical to that reported experimentally for the established Cr⋮Cr triple bond in (η5-Me5C5)2Cr2(CO)4.",

year = "2003",

month = oct,

doi = "10.1021/jp030804b",

language = "American English",

volume = "107",

journal = "The Journal of Physical Chemistry A",

}

TY - JOUR

T1 - Chromium−Chromium Multiple Bonding in Cr2(CO)9

AU - Li, Se

AU - Richardson, Nancy A.

AU - King, R Bruce

AU - Schaefer, Henry F

N1 - Density functional theory (DFT) is used to obtain the first structural characterization of the unsaturated dichromium carbonyl Cr2(CO)9, which is predicted to have a remarkably short metal−metal bond length of 2.31 Å (B3LYP) or 2.28 Å (BP86). This chromium−chromium distance is essentially identical to that reported experimentally for the established Cr⋮Cr triple bond in (η5-Me5C5)2Cr2(CO)4.

PY - 2003/10

Y1 - 2003/10

N2 - Density functional theory (DFT) is used to obtain the first structural characterization of the unsaturated dichromium carbonyl Cr 2 (CO) 9 , which is predicted to have a remarkably short metal−metal bond length of 2.31 Å (B3LYP) or 2.28 Å (BP86). This chromium−chromium distance is essentially identical to that reported experimentally for the established Cr&vellip;Cr triple bond in (η 5 -Me 5 C 5 ) 2 Cr 2 (CO) 4 . The dissociation energy to the fragments Cr(CO) 4  and Cr(CO) 5  is determined to be 32 kcal/mol (B3LYP) or 43 kcal/mol (BP86). For comparison, the Cr 2 (CO) 10  molecule and the saturated Cr 2 (CO) 11  system have negligible dissociation energies. The minimum energy Cr 2 (CO) 9  structure is of  C s  symmetry with the two chromium atoms asymmetrically bonded to the bridging carbonyls. However, within 0.1 kcal/mol lies a  C 2  symmetry structure with one symmetric and two asymmetric bridging carbonyls. Furthermore, the high symmetry  D 3 h  structure analogous to Fe 2 (CO) 9  lies only &sim;1 kcal/mol higher in energy. The Cr 2 (CO) 9  molecule is thus highly fluxional. The extremely flat potential energy surface in the region adjacent to these minima suggests that Cr 2 (CO) 9  will be labile. The relationship between the Cr 2 (CO) 9  molecule and the experimentally known binuclear manganese (η 5 -Me 5 C 5 ) 2 Mn 2 (μ-CO) 3  compound is explored.

AB - Density functional theory (DFT) is used to obtain the first structural characterization of the unsaturated dichromium carbonyl Cr 2 (CO) 9 , which is predicted to have a remarkably short metal−metal bond length of 2.31 Å (B3LYP) or 2.28 Å (BP86). This chromium−chromium distance is essentially identical to that reported experimentally for the established Cr&vellip;Cr triple bond in (η 5 -Me 5 C 5 ) 2 Cr 2 (CO) 4 . The dissociation energy to the fragments Cr(CO) 4  and Cr(CO) 5  is determined to be 32 kcal/mol (B3LYP) or 43 kcal/mol (BP86). For comparison, the Cr 2 (CO) 10  molecule and the saturated Cr 2 (CO) 11  system have negligible dissociation energies. The minimum energy Cr 2 (CO) 9  structure is of  C s  symmetry with the two chromium atoms asymmetrically bonded to the bridging carbonyls. However, within 0.1 kcal/mol lies a  C 2  symmetry structure with one symmetric and two asymmetric bridging carbonyls. Furthermore, the high symmetry  D 3 h  structure analogous to Fe 2 (CO) 9  lies only &sim;1 kcal/mol higher in energy. The Cr 2 (CO) 9  molecule is thus highly fluxional. The extremely flat potential energy surface in the region adjacent to these minima suggests that Cr 2 (CO) 9  will be labile. The relationship between the Cr 2 (CO) 9  molecule and the experimentally known binuclear manganese (η 5 -Me 5 C 5 ) 2 Mn 2 (μ-CO) 3  compound is explored.

KW - Group theory

KW - Chromium

KW - Chemical structure

KW - Carbonyls Transition metals

UR - https://pubs.acs.org/doi/10.1021/jp030804b

U2 - 10.1021/jp030804b

DO - 10.1021/jp030804b

M3 - Article

VL - 107

JO - The Journal of Physical Chemistry A

JF - The Journal of Physical Chemistry A

ER -

Chromium−Chromium Multiple Bonding in Cr2(CO)9

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