Use of Co(III)(trien) in the synthesis of amino acids and related compounds ; Synthesis of precursors of organic conductors and their metal complexes

Abstract

The research undertaken in Part I was to explore the use of substitutionally inert Co(III)(trien) complexes of amino acids, amino acid esters, and peptides for synthetic purposes. A number of Co(III)(trien) complexes with glycine, glycine esters, L-alanine, and L-homoserine were synthesized. The (Co(III)(trien)homoserinato) Cl$\sb2$.6H$\sb2$O complex was used to prepare (Co(trien)-1-aminocyclopropane-1-carboxylato) Cl$\sb2$.H$\sb2$O. Co(III)(trien)(C-formylglycine) was also prepared and reacted with (S)-penicillamine to give four isomers of Cis-$\beta\sb2$- (Co(III)(trien)-penicillinato) ClO$\sb4$ complex. Two of the isomers were resolved by reaction of the Cis-$\beta\sb2$- (Co(III)(trien)penicillinato) ClO$\sb4$ complex with barium d-tartrate. The Co(III)(trien)(C-formylglycine) synthon was reacted with 2-aminothiophenol to give Cis-$\beta\sb2$- (Co(III)(trien)(2-(2-benzothiazolyl)-2-ene glycinato)) Cl$\sb2$.H$\sb2$O complex. Attempted bromination of the chelated glycine resulted in a complete removal of the glycine. In Part II, the reaction of 2,3-dichloronaphthoquinone with K$\sb2$S and CS$\sb2$ in DMF and subsequent reactions produced a number of quinonedithiafulvalenes. The product distribution depends upon the order of reagent addition and upon temperature. Metal naphthoquinone dithiolate complexes of Co(III), Cu(III), Ni(II), Pd(II), Pt(II), Zn(II), and Mn(II) were synthesized. These complexes were characterized by Chemical analysis, X-ray diffraction, Infrared, Cyclic voltammetry, Epr, and Magnetic susceptibility. Polymeric metal tetrathiolates were also synthesized by treatment of the sodium salt of benzoquinone-tetrathiolate with aqueous CuCl$\sb2$ and n-tetrabutylammonium iodide. The tetrathiolate polymer gave a conductivity of 1 S cm$\sp{-1}$. Polymeric quinonedithiafulvalenes were synthesized; the polymer is black and insoluble in almost all solvents. It gave a room temperature conductivity of 10 S cm$\sp{-1}$. Short oligomers were also synthesized by reacting a mixture of sodium salts of benzoquinone-2,3,5,6-tetrathiolate and naphthoquinone-2,3-dithiolate with CuCl$\sb2$. The oligomers could be partially separated on an anion exchange column into two fractions. Dark green microcrystals were recovered. There is continued effort to obtain crystals suitable for X-ray studies, which will reveal the lengths of these oligomers.