Organogold(I) complexes of a C2-symmetric diacetylide ligand derived from 1,1′-bi-2-naphthol

Alkynylgold(I) complexes incorporating a chiral binaphthyl group have been prepared. Bis(alkyne) reagents [rac-1,1′-C20H12-2,2′-(OCH2Ctriple bond; length of mdashCH)2] (1) and [rac-1,1′-C20H12-2,2′-(OC(O)CH2Ctriple bond; length of mdashCH)2] (2), react with [AuCl(SMe2)] and base to give insoluble oligomeric alkynylgold(I) complexes [rac-1,1′-C20H12-2,2′-(OCH2Ctriple bond; length of mdashCAu)2]n (3) and [rac-1,1′-C20H12-2,2′-(OC(O)CH2Ctriple bond; length of mdashCAu)2]n (4), which react with phosphine or diphosphine ligands to give soluble complexes [rac-1,1′-C20H12-2,2′-(OCH2Ctriple bond; length of mdashCAuPR3)2] (5), R = Ph or Cy, [rac-1,1′-C20H12-2,2′-(OCH2Ctriple bond; length of mdashCAu)2(Ph2P(CH2)nPPh2)] (6), or [rac-1,1′-C20H12-2,2′-(OC(O)CH2Ctriple bond; length of mdashCAu)2(Ph2P(CH2)nPPh2)] (7), with n = 3–5. Several of the complexes 6 and 7 are shown to exist as mixtures of isomeric forms in solution.