Synthesis and characterisation of some azo-containing phosphine complexes of Au(I): crystal and molecular structure of [Au(CCPh){6-P(Ph)2-1-(4-Me2NC6H4N2)C10H5-2-OH}]·CHCl3

Reduction of Na[AuCl4] followed by in situ addition of a stoichiometric amount of L{L=1-(4-RC6H4)-2-OR′-6-Ph2PC10H5; R′=H, R=Me (I); R=NMe2 (II); R=NO2 (III); R′=C(O)Me; R=Me (IV); R=NMe2 (V)} affords the Au(I) complexes [LAuCl] 1a–1e (L=I, 1a; II, 1b; III, 1c; IV, 1d; V, 1e) in good yield. Treatment of 1a–1c with two molar equivalents of LiCCR″ (R″=Ph, nBu) affords the acetylide containing complexes [Au(CCR′′)L] 2a–2f {R=Ph, L=I, 2a, L=II, 2b, L=III, 2c; R=nBu, L=I, 2d, L=II, 2e, L=III, 2f} in good yield. The reaction of 1d or 1e with LiCCPh affords 2a and 2b, respectively, in which reaction of the acetylide ion with the complex takes place both at the metal centre and the ester group of the phosphine ligand. All of the compounds have been fully characterised by spectroscopic techniques and 2b·CHCl3 by a single crystal X-ray diffraction study. The solid state structure of 2b·CHCl3 shows a close Cl3CH⋯CC π-interaction and no Au⋯Au interaction.