Synthesis, characterization and properties of cooper(II) beta-diketonate macrocycles

This dissertation deals with the synthesis and properties of multidentate β-diketone ligands and their transition-metal complexes. (1) We prepared two bis(β-diketones), C1BAH2 and p-XBAH2 (see sketch below), determined their crystal structures, and studied their reactions with copper(II). We envisioned that they would form macrocyclic complexes with 3-6 metal atoms. In both cases, although the initial products are soluble, as expected for the desired molecular products, we were unable to isolate well-behaved molecular solids. In the case of C1BAH2, this may be because the cyclic product requires an unusual combination of conformations of successive ligands. (2) We studied the reactions of Cu2(NBA)2 (shown below) with the heterocyclic sulfur bases 1,4-dithiane and 2,5-dihydroxy-1,4-dithiane. The reaction with 1,4-dithiane produces a 1:1 adduct with the guest molecule internally coordinated to the Cu atoms of the host. The affinity of the Cu2(NBA)2 host for 1,4-dithiane is very small. The substituted derivative 2,5-dihydroxy-1,4-dithiane was also studied as a potential guest, but its solubility is not compatible with that of the Cu2(NBA)2 host. (3) We attempted to determine if extending the aliphatic chains of our NBAH2 and p-XBAH2 ligands would increase their solubility in organic solvents and afford us the versatility to extend our groups study of binuclear transition metal complex host-guest systems. We successfully synthesized Cu2(NBPr)2, which contains ethyl groups in place of the methyl groups of Cu2(NBA)2. However, the new Cu2(NBPr)2 host is not significantly more soluble in common organic solvents than the parent Cu2(NBA)2