An investigation of various metal complexes of orotic acid and its derivatives

A variety of metal complexes involving orotic add have been synthesized and characterized in solution and in the solid state. Reactivity of these metal complexes with small molecules has also been investigated. Orotic add is one of the major precursors in the body for the biosynthesis of the pyrimidine bases of DNA. It also happens to be a unique and interesting ligand in inorganic chemistry.; Group 6 metal (0) carbonyl complexes of orotic acid were synthesized and characterized by a variety of methods including FT-IR, 13C NMR, and in the solid state by X-ray crystallography. These complexes were observed to undergo facile dissociative CO exchange in the presence of excess 13CO. This is indicative of the stabilization of the coordinatively unsaturated transition state by the pi-donation of the orotate ligand. This pi-donating ability can be quantified in terms of the rate constant for 13CO exchange and compared to other previously characterized amido-type pi-donors. This type of kinetic study was performed with several orotate derivatives.; Another aspect of metal orotate chemistry covered herein is the synthesis of a variety of copper (I) bis-phosphine orotates. These complexes represent the first examples of copper (I) orotates known. The complexes were characterized by FT-IR 31P NMR, and X-ray crystallography. Several different approaches were used to obtain copper orotate complexes that were soluble, as most of the complexes were highly insoluble in most common organic solvents. Cu(PCy3)2(orotate) was found to be soluble in dichloromethane, and was tested for decarboxylation ability. However, the conditions at which the complex remained stable proved to be inadequate to affect decarboxylation of the orotate.; Several other aspects of metal orotate chemistry were studied. The binding mode of orotic add and its derivatives in a variety of situations was investigated. The synthesis and characterization of additional organometallic complexes of orotate derivatives was also attempted.