Diphosphine Ligand Activation Studies with Organotransition-Metal Compounds Metadata
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Title
- Main Title Diphosphine Ligand Activation Studies with Organotransition-Metal Compounds
Creator
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Author: Wang, JianchengCreator Type: Personal
Contributor
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Chair: Richmond, MichaelContributor Type: PersonalContributor Info: Major Professor
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Committee Member: Schwartz, MartinContributor Type: Personal
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Committee Member: Golden, Teresa D.Contributor Type: Personal
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Committee Member: Wiedenfeld, DavidContributor Type: Personal
Publisher
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Name: University of North TexasPlace of Publication: Denton, Texas
Date
- Creation: 2000-12
Language
- English
Description
- Content Description: Thermolysis of CoRu(CO)7(m -PPh2) (1) in refluxing 1,2-dichloroethane in the presence of the diphosphine ligands 2,3-bis(diphenylphosphino)maleic anhydride (bma) and 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) furnishes the new mixed-metal complexes CoRu(CO)4(μ -P-P)(μ -PPh2) [where P-P = bma (3); bpcd (6)], along with trace amounts of the known complex CoRu(CO)6(PPh3)(μ -PPh2) (4). The requisite pentacarbonyl intermediates CoRu(CO)5(μ -P-P)(μ -PPh2) [where P-P = bma (2); bpcd (5)] have been prepared by separate routes and studied for their conversion to CoRu(CO)4(μ -P-P)(μ -PPh2). The complexes 2/3 and 5/6 have been isolated and fully characterized in solution by IR and NMR spectroscopy. The kinetics for the conversion of 2→3 and of 5→6 were measured by IR spectroscopy in chlorobenzene solvent. On the basis of the first-order rate constants, CO inhibition, and the activation parameters, a mechanism involving dissociative CO loss as the rate-limiting step is proposed. The solid-state structure of CoRu(CO)4(μ -bma)(μ -PPh2) (3) reveals that the two PPh2 groups are bound to the ruthenium center while the maleic anhydride π bond is coordinated to the cobalt atom. Thermolysis of the cluster Ru3(CO)12 with the bis(phosphine)hydrazine ligand (MeO)2PN(Me)N(Me)P(OMe)2 (dmpdmh) in toluene at 75°C furnishes the known clusters Ru4(CO)12[μ -N(Me)N(Me)] (9) and Ru3(CO)11[P(OMe)3] (10), in addition to the new cluster Ru3(CO)10(dmpdmh) (8) and the phosphite-tethered cluster Ru3(CO)9[μ -P(OMe)3] (11). The simple substitution product Ru3(CO)10(dmpdmh), a logical intermediate to clusters 9-11, was synthesized by treating Ru3(CO)12 and dmpdmh with Me3NO in CH2Cl2 at room temperature, and independent thermolysis reactions using cluster 8 were shown to yield clusters 9-11. The tetrahedrane cluster FeCo2(CO)9(μ3-S) reacts with the redox-active ligand 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione (bpcd) to give the disubstituted cluster FeCo2(CO)7(bpcd)(μ3-S) as the sole product. This diphosphine-substituted cluster contains a cobalt-bound, chelating bpcd ligand. The solid-state structure has been unequivocally established by X-ray diffraction analysis. Cyclic voltammetric studies on FeCo2(CO)7(bpcd)(μ3-S) reveal the presence of two quasireversible redox responses assigned to the 0/1- and 1-/2- redox couples. The orbital composition of these redox couples has been examined by carrying out extended Hückel MO calculations on the model complex FeCo2(CO)7(H4-bpcd)(μ3-S), with the results being compared to related cluster compounds.
Subject
- Library of Congress Subject Headings: Ligands.
- Library of Congress Subject Headings: Organotransition metal compounds.
- Keyword: thermolysis
- Keyword: diphosphine ligands
- Keyword: new mixed-metalcomplexes
Collection
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Name: UNT Theses and DissertationsCode: UNTETD
Institution
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Name: UNT LibrariesCode: UNT
Rights
- Rights Access: unt
- Rights License: copyright
- Rights Holder: Wang, Jiancheng
- Rights Statement: Copyright is held by the author, unless otherwise noted. All rights reserved.
Resource Type
- Thesis or Dissertation
Format
- Text
Identifier
- OCLC: 47785437
- Archival Resource Key: ark:/67531/metadc2665
Degree
- Degree Name: Doctor of Philosophy
- Degree Level: Doctoral
- Degree Discipline: Chemistry
- Academic Department: Department of Chemistry
- Degree Grantor: University of North Texas