Date of Award

8-2011

Document Type

Thesis

Degree Name

Master of Science (MS)

College/School

College of Science and Mathematics

Department/Program

Chemistry and Biochemistry

Thesis Sponsor/Dissertation Chair/Project Chair

Mark A. Whitener

Committee Member

John L. Isidor

Committee Member

James Dyer

Abstract

Quasiracemates contain two molecules (or ions) of opposite handedness, in which one enantiomer has a substitution of a chemically different, but similarly shaped group. Metal based complexes that are enantiomeric, racemic and quasiracemic were synthesized. Racemic metal compounds are synthesized from equimolar concenteration of chemically identical ligands having both handedness (R and S). Quasiracemic metal complexes were synthesized from two stercially similar, but chemically different ligands, and these complexes tend to mimic the centrosymmetric pattern in racemic metal complexes. This project was begun by previous master’s student, Hiral Patel, to study the crystal packing of metal based quasiracemic complexes, and the goal of this study was to extend this approach. Substituted A-phthaloylalanines were synthesized and characterized by 1H-NMR. Anions of these compounds and A-methylimdiazole are used as ligands to prepare metal complexes with a square planar geometry about copper. Two new crystal structures and one improved structure previously done determined. The new structures are (1) a new quasiracemate, bis(A-methylimidazole)((D)-3-chloro-A-pthaloyalaninato)(( L)-3-nitro-phthaloylalaninato)copper(II), Cu(7,D)(9,L)(JV-MeIm)2, (2) a racemate, bis(A-methylimidazole)bis((D,L)-3-methyl-vV-pthaloylalaninato)-copper(II), Cu(2,D,L)2(A-MeIm)2, and (3) an improved structure of quasiracemate, bis(Amethylimidazole)(( D)-3-chloro-7V-phthaloyalaninato)((L)-3-methyl-phthaloylalaninato)- copper(II) Cu(7,D)(2,L)(A-MeIm)2. The chloro and nitro groups are disordered in both the quaisracemic complexes and the methyl phthaloyl ring is disordered over three and two positions in the quaisracemic and the racemic complexes, respectively. Analysis of the structures showed that crystal packing of quaisracemic and racemic complexes is similar, whereas the enantiomeric complex has a different packing pattern.

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