Crystal and molecular structure of (6-n-propyl-2-thiouracilato)tricyclohexylphosphinegold(I)

Abstract

Abstract The crystal structure of the title compound (6-n-propyl-2-thiouracilato)tricyclohexylphosphinegold(I), [(c-C6H11)3PAu(PTU)], has been determined at room temperature. The colorless crystals are monoclinic, space group P21/c with unit cell dimensions a = 9.539(2) Å, b = 16.452(4) Å, c = 16.880(2) Å, β = 95.37(2)°, Z = 4 and Dx = 1.628 Mg m−3. The structure was solved by direct-methods and refined by a full-matrix least-squares procedure to final R = 0.043 using 3695 reflections. In the structure of [(c-C6H11)3PAu(PTU)] the Au atom is linearly coordinated by the P atom (Au–P 2.248(3) Å) and the S atom (Au–S 2.302(3) Å) such that the P–Au – S angle is 177.6(1)°. A close intramolecular contact between the Au atom and a thiouracilate-bound N atom of 3.061(9) Å is not indicative of a significant interaction between these atoms. The lattice is comprised of centrosymmetrically related molecules that are associated via hydrogen bonding contacts between the carbonyl O(4) atom and the H N(3) atom; O(4) … H is 1.90(1) Å and the O(4) … H–N(3) angle is 161(1)°. An examination of a series of R3PAu(thiouracilate) derivatives reveal that the Au atom geometry is largely independent of the nature of the phosphine ligand, at least when R = Et, Ph or c-C6H11.