Reactions of (tertiary phosphine)gold(I)) substituted imidazoles or pyrazolones with acidic reagents: protonation, azole displacement, and adduct formation. Crystal structure determination of the adduct 1-methyl-2-(cyclohexylphosphinegoldthiolato)imidazole*2benzimidazole

Article abstract of DOI:10.1016/0022-328X(88)80218-3

Imidazole (QH) or pyrazolone (Q'H2) in QAuL or (LAu)2Q' (where L is a tertiary phosphine is displaced by some acidic reagents HL, wherw HZ=terminal acetylene, imide, thiol, dithio acid, or HI, to give ZAuL.If Z^- is not a soft ligand an adduct between the reagents is obtained, and this is formulated as a protonated species, e.g. ⁺Z^- (HZ=picric acid).In other cases the adduct is LAuZ*HQ (rather than LAuQ*HZ or a protonated species), in which the displaced QH is hydrogen-bonded to the product, as shown by the crystal structure of the adduct 1-methyl-2-(cyclohexylphosphinegoldthiolato)imidazole*2benzimidazole.In this species gold(I) is two-coordinated (P-Au-S 172.0(1), with Au-P and Au-S 2.292(3) and 2.331(3) Angstroem, respectively; the first benzimidazole is hydrogen-bonded to N(3) of the imidazole , and the second benzimidazole to the N(3) of the first, the inter-diazole N...H-N distance being 2.81 and 2.86(1) Angstroem, respectively.