Rare Au···H Interactions in Gold(I) Complexes of Bulky Phosphines Derived from 2,6Dibenzhydryl-4-methylphenyl Core.

Gold(I) complexes of sterically demanding phosphines derived from 2,6-dibenzhydryl-4-methylphenyl core : 2,6-dibenzhydryl-,-bis((diphenylphosphane)-methyl)-4-methylaniline (), (2,6-dibenzhydryl-4-methylphenyl)-diphenylphosphane (), -(2,6-dibenzhydryl-4-methylphenyl)-1,1-diphenylphosphanamine (), and (2,6-dibenzhydryl-4-methylphenoxy)-diphenylphosphane () are described. The reaction of with 2 equiv of [AuCl(SMe)] in dichloromethane yielded [{AuCl}{Ar*N(CHPPh)}] (), which on further treatment with 2 equiv of AgSbF and 1 equiv of produced 12-membered dimeric complex [Au{μ-(Ar*N(CHPPh))}][(SbF)] (). A similar reaction of with AgSbF in CHCN afforded [{Au(NCCH)}{Ar*N(CHPPh)}][(SbF)] (). Equimolar reactions of bulky phosphines , , and with [AuCl(SMe)] resulted in [AuCl(PPhAr*)] (), [AuCl(PPhNHAr*)] (), and [AuCl(PPhOAr*)] (). Complexes and on treatment with AgSbF in CHCN produced the cationic complexes [Au(NCCH)(PPhNHAr*)][(SbF)] () and [Au(NCCH)(PPhOAr*)][(SbF)] (), respectively. The molecular structure of complex revealed the presence of a strong intramolecular aurophilic interaction with a Au···Au distance of 2.9720(4) Å. Careful analysis of molecular structure of revealed the presence of rare Au···H-C () interactions between the gold(I) atom and one of the methylene protons of -NCHPPh groups. The solution H NMR signals of the methylene protons of showed a considerable downfield shift (∼1 ppm) compared to that of the free ligand indicating their interactions (Au···H) with the Au atom. Complexes and also showed Au···H interactions in their molecular structures. The existence of the Au···H interaction was studied by variable temperature H NMR data in the case of complex and further evinced by the QTAIM analysis in complexes , , and .