Title

Homogeneous sulfide oxygenation via manganese and ruthenium catalysts and interactions between [copper(2)([18]ane nitrogen(6))](4+) and phosphates

Date of Award

2006

Availability

Article

Degree Name

Doctor of Philosophy (Ph.D.)

Department

Chemistry

First Committee Member

Tong Ren, Committee Chair

Abstract

Both mono- and binuclear Mn-Me3TACN (Me3 TACN is 1,4,7-N,N',N"-trimethyl-1,4,7-triazacyclononane) compounds are analyzed for their efficacy in oxo-transfer to both organic sulfides and alkenes under ambient conditions. Binuclear complexes are effective in oxo-transfer with H2O2, and the turnover frequency (TOF) increases up to 40 fold in the presence of oxalate. Mononuclear complexes, in combination with tert-butyl hydroperoxide (TBHP), yield TOFs up to 200 h-1, and may selectively produce either sulfoxide or sulfone products. Mechanistic aspect for each complex is postulated.Additional oxo-transfer studies with organic sulfides are investigated in the presence of TBHP with two diruthenium paddlewheel complexes: Ru 2(OAc)4Cl and Ru2(esp)2Cl. The crystallographic structure for the latter is presented. Ru2(esp)2Cl catalyzes the solvent free oxygenation of methyl phenyl sulfide with TBHP, producing TOFs up to 2000 h-1. Kinetic investigations are pursued for each compound, revealing catalytic variation of the Ru2 complexes in relation to their equatorial substituents. A plausible means of oxo-transfer for each complex is postulated.In further studies, a novel cationic copper complex {[18]aneN6Cu 2(mu-O-OAc)2}2+ is synthesized that undergoes anion displacement with hydrogen phosphate (HPO4) 2-, phenyl phosphate (PhPO4)2- and beta-glycerol phosphate (beta-GPO4)2-. Crystallographic structures of each are presented. Unbuffered and buffered binding studies of the acetate complex reveal high affinities for phosphate monoesters of ∼10 4 and 103, respectively. Structural insights in biological phosphate ester hydrolysis may be derived from the topological features of the phosphate monoester complexes.

Keywords

Chemistry, Inorganic

Link to Full Text

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