Mono- and Dimeric Gold(I) Complexes with Cyclic Arsine Ligands

Dimeric gold(I) complexes were synthesized by reaction of cyclic arsine ligands with chloro(tetrahydrothiophene)gold(I) in an equimolar ratio in methylene chloride. In the case of 10-(6-methylpyridin-2-yl)phenoxarsine, a monomeric structure with As-monodentate ligand was isolated. The complex was identified and characterized using a set of analytical methods (mass spectrometry, 1H NMR spectroscopy, elemental analysis, X-ray diffraction). Tolman angles were determined to assess the steric bulk of arsine ligands. DFT calculations were confirmed that the dimeric form is energetically more favorable compared to the monomeric structure.