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Title:Alkylidene Dirhodium Chemistry
Author(s):Dimas, Peter Allan
Department / Program:Chemistry
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Chemistry, Inorganic
Abstract:Alkylidene-bridged complexes have been prepared from unsaturated dirhodium complexes and diazo compounds. Several aspects of the reactivity of the alkylidene group in these and related complexes have been examined.
The unsaturated complex {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)((mu)-CO)}(,2) reacts with diazo compounds to form the (mu)-alkylidene complexes {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)(CO)(,2)((mu)-CRR')}. Thermolysis of {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)(CO)(,2)((mu)-CPh(,2))} results in decarbonylation to give {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)((mu)-CO)((mu)-CPh(,2))}. The unsaturated complex {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)((mu)-NO)((mu)-CO)}BF(,4) has been prepared from {((eta)('5)-C(,5)Me(,5))Rh(CO)(,2)} and NOBF(,4). It also reacts with diazo compounds (-78(DEGREES)C) to form (mu)-alkylidene complexes which decarbonylate upon warming to room temperature resulting in the novel series of unsaturated complexes {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)((mu)-NO)((mu)-CRR')}BF(,4). Acetylene inserts into the metal-alkylidene bonds of {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)((mu)-NO)((mu)-CHPh)}BF(,4) to form the stable vinylmethylidene compound {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)((mu)-NO)((mu)-(eta)('1),(eta)('3)-CHCHCHPh)}BF(,4).
The bis-alkylidene complex(' ){((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)((mu)-C(H)C(OEt)OC-(H)CO(,2)Et)((mu)-NO)}BF(,4) has been prepared from {((eta)('5)-C(,5)Me(,5))(,2)Rh(,2)((mu)-NO)((mu)-CO)}BF(,4) and ethyl diazoacetate. The terminal and bridging alkylidene moieties in this complex are condensed into a unique metallocyclic ligand. Heating a solution of this complex under a carbon monoxide atmosphere induces coupling of the alkylidene moieties to form an alkene. Crossover experiments have provided evidence for an intramolecular coupling mechanism.
Treatment of {((eta)('5)-C(,5)H(,5))(,2)Rh(,2)(CO)(,2)((mu)-CHR)} (R = H, Me) with trifluoroacetic acid causes disproportionation to give CH(,3)R, {((eta)('5)-C(,5)H(,5))Rh(CO)(,2)} and the novel cationic alkylidyne clusters {((eta)('5)C(,5)H(,5))(,3)Rh(,3)((mu)-CO)(,2)((mu)(,3)-CR)}('+).
Issue Date:1983
Description:202 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983.
Other Identifier(s):(UMI)AAI8324536
Date Available in IDEALS:2014-12-17
Date Deposited:1983

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