New metal-organic polygons involving MM quadruple bonds: M 8(O2CtBu)4(μ-SC4H 2-3,4-{CO2}2)6 (M = Mo, W)

Matthew J. Byrnes, Malcolm H. Chisholm, Nathan J. Patmore

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

The reactions between M2(O2CtBu) 4, where M = Mo or W, and thienyl-3,4-dicarboxylic acid (0.5-1.5 equiv) in toluene proceed via a series of detectable intermediates to the compounds M8(O2CtBu)4(μ-SC 4H2-SC4H2-3,4-{CO2} 2)6, which are isolated as air-sensitive yellow (M = Mo) or red (M = W) powders and show parent molecular ions in , their mass spectra (MALDI). The structure of the molybdenum complex was determined by single-crystal X-ray crystallography and shown to contain an unusual M 8 polygon involving four Mo2 quadruply bonded units linked via the agency of the six 3,4-thienylcarboxylate groups. The structure has crystallographically imposed S4 symmetry and may be described in terms of a highly distorted tetrahedron of Mo2 units or a bisphenoid in which two Mo2 units are linked by a thienyldicarboxylate such that intramolecular Mo2⋯O bonding is present, while the other thienylcarboxylate bridges merely serve to link these two [Mo 2]⋯[Mo2] units together. The color of the compounds arises from intense M2 δ-to-thienyl π* transitions and, in THF, the complexes are redox-active and show four successive quasi-reversible oxidation waves. The [M8]+ radical cations, generated by one-electron oxidation with AgPF6, are shown to be valence-trapped (class II) by UV-vis-near-IR and electron paramagnetic resonance spectroscopy. These results are supported by the electronic structure calculations on model compounds M8(O2CH) 4(μ-SC4H2-3,4-{CO}2)6 employing density functional theory that reveal only a small splitting of the M2 δ manifold via mixing with the 3,4-thienylcarboxylate π system.

LanguageEnglish
Pages9347-9352
Number of pages6
JournalInorganic Chemistry
Volume44
Issue number25
Early online date11 Nov 2005
DOIs
Publication statusPublished - 12 Dec 2005
Externally publishedYes

Fingerprint

polygons
Metals
Oxidation
Dicarboxylic Acids
oxidation
Molybdenum
dicarboxylic acids
X ray crystallography
Toluene
Carbon Monoxide
molecular ions
tetrahedrons
Powders
metals
mass spectra
crystallography
Electronic structure
molybdenum
Density functional theory
Paramagnetic resonance

Cite this

@article{b0aad8d281904b48a18ccc8476a603c8,
title = "New metal-organic polygons involving MM quadruple bonds: M 8(O2CtBu)4(μ-SC4H 2-3,4-{CO2}2)6 (M = Mo, W)",
abstract = "The reactions between M2(O2CtBu) 4, where M = Mo or W, and thienyl-3,4-dicarboxylic acid (0.5-1.5 equiv) in toluene proceed via a series of detectable intermediates to the compounds M8(O2CtBu)4(μ-SC 4H2-SC4H2-3,4-{CO2} 2)6, which are isolated as air-sensitive yellow (M = Mo) or red (M = W) powders and show parent molecular ions in , their mass spectra (MALDI). The structure of the molybdenum complex was determined by single-crystal X-ray crystallography and shown to contain an unusual M 8 polygon involving four Mo2 quadruply bonded units linked via the agency of the six 3,4-thienylcarboxylate groups. The structure has crystallographically imposed S4 symmetry and may be described in terms of a highly distorted tetrahedron of Mo2 units or a bisphenoid in which two Mo2 units are linked by a thienyldicarboxylate such that intramolecular Mo2⋯O bonding is present, while the other thienylcarboxylate bridges merely serve to link these two [Mo 2]⋯[Mo2] units together. The color of the compounds arises from intense M2 δ-to-thienyl π* transitions and, in THF, the complexes are redox-active and show four successive quasi-reversible oxidation waves. The [M8]+ radical cations, generated by one-electron oxidation with AgPF6, are shown to be valence-trapped (class II) by UV-vis-near-IR and electron paramagnetic resonance spectroscopy. These results are supported by the electronic structure calculations on model compounds M8(O2CH) 4(μ-SC4H2-3,4-{CO}2)6 employing density functional theory that reveal only a small splitting of the M2 δ manifold via mixing with the 3,4-thienylcarboxylate π system.",
author = "Byrnes, {Matthew J.} and Chisholm, {Malcolm H.} and Patmore, {Nathan J.}",
year = "2005",
month = "12",
day = "12",
doi = "10.1021/ic051516s",
language = "English",
volume = "44",
pages = "9347--9352",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "25",

}

New metal-organic polygons involving MM quadruple bonds : M 8(O2CtBu)4(μ-SC4H 2-3,4-{CO2}2)6 (M = Mo, W). / Byrnes, Matthew J.; Chisholm, Malcolm H.; Patmore, Nathan J.

In: Inorganic Chemistry, Vol. 44, No. 25, 12.12.2005, p. 9347-9352.

Research output: Contribution to journalArticle

TY - JOUR

T1 - New metal-organic polygons involving MM quadruple bonds

T2 - Inorganic Chemistry

AU - Byrnes, Matthew J.

AU - Chisholm, Malcolm H.

AU - Patmore, Nathan J.

PY - 2005/12/12

Y1 - 2005/12/12

N2 - The reactions between M2(O2CtBu) 4, where M = Mo or W, and thienyl-3,4-dicarboxylic acid (0.5-1.5 equiv) in toluene proceed via a series of detectable intermediates to the compounds M8(O2CtBu)4(μ-SC 4H2-SC4H2-3,4-{CO2} 2)6, which are isolated as air-sensitive yellow (M = Mo) or red (M = W) powders and show parent molecular ions in , their mass spectra (MALDI). The structure of the molybdenum complex was determined by single-crystal X-ray crystallography and shown to contain an unusual M 8 polygon involving four Mo2 quadruply bonded units linked via the agency of the six 3,4-thienylcarboxylate groups. The structure has crystallographically imposed S4 symmetry and may be described in terms of a highly distorted tetrahedron of Mo2 units or a bisphenoid in which two Mo2 units are linked by a thienyldicarboxylate such that intramolecular Mo2⋯O bonding is present, while the other thienylcarboxylate bridges merely serve to link these two [Mo 2]⋯[Mo2] units together. The color of the compounds arises from intense M2 δ-to-thienyl π* transitions and, in THF, the complexes are redox-active and show four successive quasi-reversible oxidation waves. The [M8]+ radical cations, generated by one-electron oxidation with AgPF6, are shown to be valence-trapped (class II) by UV-vis-near-IR and electron paramagnetic resonance spectroscopy. These results are supported by the electronic structure calculations on model compounds M8(O2CH) 4(μ-SC4H2-3,4-{CO}2)6 employing density functional theory that reveal only a small splitting of the M2 δ manifold via mixing with the 3,4-thienylcarboxylate π system.

AB - The reactions between M2(O2CtBu) 4, where M = Mo or W, and thienyl-3,4-dicarboxylic acid (0.5-1.5 equiv) in toluene proceed via a series of detectable intermediates to the compounds M8(O2CtBu)4(μ-SC 4H2-SC4H2-3,4-{CO2} 2)6, which are isolated as air-sensitive yellow (M = Mo) or red (M = W) powders and show parent molecular ions in , their mass spectra (MALDI). The structure of the molybdenum complex was determined by single-crystal X-ray crystallography and shown to contain an unusual M 8 polygon involving four Mo2 quadruply bonded units linked via the agency of the six 3,4-thienylcarboxylate groups. The structure has crystallographically imposed S4 symmetry and may be described in terms of a highly distorted tetrahedron of Mo2 units or a bisphenoid in which two Mo2 units are linked by a thienyldicarboxylate such that intramolecular Mo2⋯O bonding is present, while the other thienylcarboxylate bridges merely serve to link these two [Mo 2]⋯[Mo2] units together. The color of the compounds arises from intense M2 δ-to-thienyl π* transitions and, in THF, the complexes are redox-active and show four successive quasi-reversible oxidation waves. The [M8]+ radical cations, generated by one-electron oxidation with AgPF6, are shown to be valence-trapped (class II) by UV-vis-near-IR and electron paramagnetic resonance spectroscopy. These results are supported by the electronic structure calculations on model compounds M8(O2CH) 4(μ-SC4H2-3,4-{CO}2)6 employing density functional theory that reveal only a small splitting of the M2 δ manifold via mixing with the 3,4-thienylcarboxylate π system.

UR - http://www.scopus.com/inward/record.url?scp=29544439039&partnerID=8YFLogxK

U2 - 10.1021/ic051516s

DO - 10.1021/ic051516s

M3 - Article

VL - 44

SP - 9347

EP - 9352

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 25

ER -