Gold(I) Compounds without Significant Aurophilic Intermolecular Interactions: Synthesis, Structure, and Electronic Properties of Ph₃PAuC(O)NHMe and Au₃(PhCH₂NCOMe)₃: Comparative Monomeric and Trimeric Analogues of the Solvoluminescent Trimer, Au₃(MeNCOMe)₃

The preparations of Ph3PAuC(O)NHMeand Au3(PhCH2NCOMe)3 are reported. In solution Ph3PAuC(O)NHMe is unstable and readily deposits metallic gold. Colorless needles of the monomeric complex, Ph3PAuC(O)NHMe, crystallize in the monoclinic space group P21/c, with a = 8.993(2) Å, b = 22.583(5) Å, c = 8.932(2) Å, β = 98.22(2)°, at 123 K with Z = 4. Refinement of 2609 reflections and 114 parameters yielded R = 0.0455. A hydrogen-bonded intermolecular network links molecular units through N−H···O hydrogen bonds. No aurophilic interactions are present in this solid. The crystal structure of the cyclic trinuclear organogold compound, Au3(PhCH2NCOMe)3, reveals that the complex does not associate into a trigonal prismatic array via intermolecular interactions of gold(I) centers as is seen in the triangular complex, Au3(MeNCOMe)3. Rather, the complex packs in a stair-step fashion with eight discrete molecules in the asymmetric unit. Additionally, the solvent-stimulated emission (solvoluminescence) associated with Au3(MeNCOMe)3 is not observed for this complex. Colorless needles of Au3(PhCH2NCOMe)3 crystallize in the monoclinic space group P21, with a = 17.311(6) Å, b = 34.761(10) Å, c = 18.052(6) Å, β = 94.73(2)°, at 133 K with Z = 16. Refinement of 16 250 reflections and 985 parameters yielded R = 0.0735.