Synthesis and characterization of alkyne adducts of Cp*Co(CpCo)ℓ(CO)ℓ.

This thesis describes the continuation of research performed in the laboratories of Dr. Barnes. Previous work has concentrated on the synthesis and characterization of cluster complexes with the general formula Cp*M_m(CpCo)³-m(CO)₂ where M = Co, Rh, Ir, m = 0 - 2, Cp = cyclopentadiene and Cp* = pentamethylcyclopentadiene. Of this series of complexes, the reactions of one in particular, (Cp)₃Co₃(Co)₂, (Co₃), have been studied in great detail. This complex contains no pentamethylcyclopentadiene ligands and all three metals are the same. Therefore, this complex may be considered to be the "simplest form" of the general formula given above. Studies of Co₃ have concentrated on two types of reactions: two and four electron donor ligand addition and cluster fragmentation.

This thesis involves the study of the reaction of alkynes (R-C=C-R') with the complex Cp*Co (CpCo)²(Co)₂, (*CoCo₂). This complex was chosen as it was thought that the presence of the bulky pentamethylcyclopentadiene ligand on the trinuclear complex may sterically hinder the addition of alkynes to the complex in the formation of alkyne adducts. Three alkynes were chosen that were of similar electronic nature but with relatively well defined differences in the size of their respective R groups. Described herein is a description of the formation of the alkyne adducts, their characterization and the results of their respective reactions with *CoCo&sub2;.