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Title:Synthesis and Characterization of Hetero- and Homobimetallic Complexes of New Hard-Soft Binucleating Ligands
Author(s):Wrobleski, Debra Ann
Department / Program:Chemistry
Degree Granting Institution:University of Illinois at Urbana-Champaign
Subject(s):Chemistry, Inorganic
Abstract:A unique feature of our unsymmetrical ligand systems is the arrangement of hard and soft donor atoms in a manner to preclude its functioning as a tridentate chelating agent. We have prepared a series of functionalized (beta)-diketone ligand systems via the Claisen condensation of orthosubstituted methyl benzoate compounds with the potassium enolate of methyl ketones. The new binucleating ligands prepared in this work include phosphine, thioether and quinoline substituted (beta)-diketones along with the Schiff-base derivatives of the thioether (beta)-diketone. With these ligand systems, we can exploit the extensive transition metal coordination chemistry of (beta)-diketonates and of "soft" donor groups to prepare complexes containing two different metals. The coordination chemistry of o-diphenylphosphinobenzoylpinacolone, HacacP, has been most extensively studied.
{Cu(,2)(acacP)(,2)} was prepared and its structure was shown to consist of two trigonally coordinated coppers situated in a face-to-face orientation. This coordinatively unsaturated binuclear complex undergoes 1e('-) oxidative addition with peroxy acids and peroxides and readily reacts with molecular oxygen to give a stable crystalline derivative. Both of these processes give mixed valence compounds of the general type {Cu(,2)(acacP)(,2)((mu)-O(,2)CR)}.
Heterobimetallic complexes containing two acacP ligands can be prepared systematically by two reaction sequences. One method involves insertion of the hard metal into the O(,4) compartment followed by coordination of a second, soft metal to the phosphine donors. Because of the incompatibility of phosphines with cupric salts, a second method must be employed for the preparation of M-Cu(acacP)(,2) complexes. This involves coordination of the phosphines to the soft metal followed by metalation of the O(,4) site. In this way the following heterobimetallic compounds were prepared: ML(,2){M'(acacP)(,2)}, M = Pt, Pd, Ru, Ir, M' = Cu, Zn, TiCl(,2). An examination of this series by NMR, EPR and optical spectroscopy has been valuable in the assignment of structures as well as in determining the extent to which these two metals interact with one another.
Monometallic Ni(II) and Cu(II) derivatives of the new Schiff-base thioether ligand, S(,2)O(,2)N(,2)('2-) and cyclo-S(,2)O(,2)N(,2)('2-), have been prepared along with a new binuclear copper complex.
Issue Date:1983
Description:151 p.
Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1983.
Other Identifier(s):(UMI)AAI8410074
Date Available in IDEALS:2014-12-15
Date Deposited:1983

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