Coordination modes of diphosphines in silver(I)?diphosphine complexes mediated by 2,4,6-tri(2-pyridyl)-1,3,5-triazine (tptz)

Abstract

Silver (I) complexes [Ag2(tptz)(dppm)2(DMF)](BF4)2·2DMF (1), [Ag(tptz)(dppe)]n(BF4)n·2nH2O·nMeOH (2), [Ag2(tptz)2(dppp)2](BF4)2(3) and [Ag2(tptz)2(dppb)](BF4)2(4) were obtained from the reactions of AgBF4 and diphosphine Ph2P(CH2) nPPh2 (Lpp, n=1–4) in the presence of 2,4,6-tris(2-pyridyl)-1,3,5-triazine (tptz) in MeOH–DMF. Single crystal analyses showed that the closed metallocyclic unit [Ag2(Lpp)2]2+ with double Lpp bridges was obtained in (1) and (3) with an odd number of n, while an open metallochain (Ag2Lpp)2+ with a single bridge formed in (2) and (4) with n being even. Coordination modes for the diphosphines are directly related to the rigid tptz ligand with a large π-system.