CARBON-FUNCTIONALIZED 1,4,7-TRITHIACYCLONONANES - SYNTHESIS, MOLECULAR MECHANICS AND COORDINATION CHEMISTRY

A series of functionalized analogues of 1,4,7-trithiacyclononane has b een synthesized and the effects of functionalization on their co-ordin ation chemistry investigated. The substituents were introduced via sub stituted 1,2-dibromopropanes, by cyclization with 3-thiapentane-1,5-di thiolate in the form of its molybdenum complex [Mo(CO)3(SCH2CH2SCH2CH2 S)]2-. The functionalized macrocycles were then displaced from the met al by additional 3-thiapentane-1,5-dithiolate. A series of complexes [ ML2]n+ (M = Ag, Hg, Cu, Ni, Co or Fe; L = 2-methyl-1,4,7-trithiacyclon onane, the simplest of the new ligands) was prepared. Spectroscopic an d electrochemical studies revealed that any effects of substitution on the ring conformational preferences were not manifested in the stabil ity or electrochemistry of the complexes. Molecular-mechanics calculat ions suggest that no alterations in conformational preferences are cau sed by a single substitution. Attempts to synthesize analogues with tw o vicinal methyl groups yielded only polymeric products.