Silver(I) bis(phosphanylamino)naphthalene complexes: Synthesis, structures and density functional theory (DFT) calculations

Abstract

A series of five bis(phosphanylamino)naphthalene [C10H6(1,8-NHPPh2)2] (L1) and thio product, [C10H6(1,8-NHP(S)Ph2)2] (L2) containing silver(I) centers are reported. Treatment of silver(I) halides AgX (X = Cl, Br) with (L1) produced complexes of the type [Ag2(μ-X)2{C10H6(1,8-NHPPh2)2}2] where X = Cl (1), Br (2). Changing the M:L ratio to 2:1, the salt AgI produced a complex of the type [Ag4(μ3-I)2(μ2-I)2{C10H6(1,8-NHPPh2)2}2] (3). The reaction between AgOTf (OTf = triflate) and (L2) (molar ratio 1:2) produced the solvated cationic complex [Ag{C10H6(1,8-NHPPh2S)2}2]CF3SO3 (4), whilst changing from OTf to other anions proved to have no influence in forming cationic complexes but instead led to deprotonation of the ligand and produced a neutral complex [Ag2(μ-S)2{C10H6(1,8-NHPPh2S)}2] (5). The 31P NMR spectra of Ag(I) complexes (1–3) showed two doublets due to coupling of the 31P and 109Ag nuclei. Molecular orbital (MO) and additional TD-DFT and spin-orbital coupling calculations were performed to provide more insight into the relevant bond orders and provided a possible explanation for solid-state non-luminescence.