Organogold(I)-uracil conjugates: Synthesis and structural characterization

Abstract

The conjugation of the gold(I) complex having planar phenyl isocyanide or bulky triphenylphosphine with 6-ethynyl-1-octyluracil afforded the corresponding gold(I) complexes U6AuCNPh and U6AuPPh3, respectively, as bioorganometallic conjugates. The crystal structure of U6AuCNPh revealed the formation of a head-to-tail dimer through the Au(I)–Au(I) and π–π interactions between the uracil and benzene moieties of phenyl isocyanide. Furthermore, each head-to-tail dimer was connected not only through the intermolecular hydrogen bonds of N–H···O pattern between the uracil moieties but the weak hydrogen bonds of C–H···O pattern between the uracil and benzene moieties of phenyl isocyanide. In contrast, the Au(I)–Au(I) interaction was not observed in a crystal structure of U6AuPPh3 probably due to the steric hindrance of the bulky triphenylphosphine ligand although a dimeric structure through the intermolecular hydrogen bonds of N–H···O pattern between the uracil moieties was formed.