Source:http://linkedlifedata.com/resource/pubmed/id/21434631
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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
15
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| pubmed:dateCreated |
2011-4-13
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| pubmed:abstractText |
The reaction between W(2)(T(i)PB)(4), where T(i)PB = 2,4,6-triisopropylbenzoate, and 2 equiv of 4-isonicotinic acid (nicH) yields the compound W(2)(T(i)PB)(2)(nic)(2), 2, and T(i)PBH. Compound 2 is related to the previously reported molybdenum analog, Mo(2)(T(i)PB)(2)(nic)(2), 1. Compounds 1 and 2 react with 2 equiv of B(C(6)F(5))(3) in THF to form the adducts M(2)(T(i)PB)(2)(nic-B(C(6)F(5))(3))(2), 1B (M = Mo) and 2B (M = W), which have been crystallographically characterized as solvates M(2)(T(i)PB)(2)(nic-B(C(6)F(5))(3))(2)·2THF n-hexane. Compounds 1 and 2 are intensely colored due to M(2) ? to ?* MLCT transitions, and upon complexation with B(C(5)F(5))(3) to give 1B and 2B, these bands shift to lower energy and gain in intensity. Each compound shows two one-electron ligand-based reductions with a ?E(1/2) = 120 (1), 300 (1B), 440 (2), and 650 mV (2B). The larger ?E(1/2) values for the tungsten compounds reflect the greater orbital mixing of the metal 5d-based M(2) ? and the nic ?* LUMO. Reduction of solutions of 1B and 2B with (C(5)Me(5))(2)Co leads to the anions 1B(-) and 2B(-), which have been characterized spectroscopically by electron paramagnetic resonance (EPR) and UV-vis-NIR absorption. The EPR spectra of 1B(-) and 2B(-) are consistent with ligand-based (i.e., organic) radicals. The electronic spectra contain low-energy narrow charge resonance (IVCT) bands at 3800 (1B(-)) and 4500 cm(-1) (2B(-)), consistent with fully delocalized mixed valence radical anions. The results are compared with electronic structure calculations and with the spectral features of the metal-centered delocalized mixed valence radical cations [(Bu(t)CO(2))(3)M(2)](2)-?(2)-(O(2)C-CO(2))(+), to which they are remarkably similar, as well as with other organic-based mixed valence systems.
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| pubmed:language |
eng
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| pubmed:journal | |
| pubmed:status |
PubMed-not-MEDLINE
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| pubmed:month |
Apr
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| pubmed:issn |
1520-5126
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| pubmed:author | |
| pubmed:issnType |
Electronic
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| pubmed:day |
20
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| pubmed:volume |
133
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| pubmed:owner |
NLM
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| pubmed:authorsComplete |
Y
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| pubmed:pagination |
5873-81
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| pubmed:year |
2011
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| pubmed:articleTitle |
Extent of M2 ? to ligand ?-conjugation in neutral and mixed valence states of bis(4-isonicotinate)-bis(2,4,6-triisopropylbenzoate) dimetal complexes (MM), where M = Mo or W, and their adducts with tris(pentafluorophenyl)boron.
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| pubmed:affiliation |
Department of Chemistry, The Ohio State University, 100 West 18th Avenue, Columbus, Ohio 43210, United States.
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| pubmed:publicationType |
Journal Article
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