Gold-dppm-Arylazoimidazole Complexes: Synthesis, Spectra, and Redox Study

Abstract

[Ag(tht)(OTf)]-assisted reaction produces [ Au III ( dppm ) ( tht ) 2 ] ( OSO 2 CF 3 ) 2 , reacts with R a a i R ′ in dichloromethane medium followed by ligand addition, and leads to [ Au III ( dppm ) ( R a a i R ′ ) ] ( OTf ) 2 ( R a a i R ′ = p –R–C 6 H 4 –N = N–C 3 H 2 –NN–1– R ′ , (1–3), abbreviated as N, N ′ -chelator, where N(imidazole) and N(azo) represent N and N ′ , resp.; R = H (a), Me (b), Cl (c) and R ′ = Me (1), CH 2 CH 3 (2), CH 2 Ph (3), dppm is diphenylphosphinomethane, OSO 2 CF 3 is the triflate anion, and tht is tetrahydrothiophen). Ir spectra of the complexes show –C=N– and –N=N– stretching near at 1590 and 1370 cm − 1 and near at 1100, 755, 695, 545, and 505 cm − 1 due to the presence of dppm. The H 1 NMR spectral measurements suggest that methylene, – CH 2 –, in RaaiEt gives a complex AB type multiplet while in Raai CH 2 Ph it shows AB type quartets. Electrochemistry assigns ligand reduction.