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

Silver ( I) complexes [Ag-2(tptz)(dppm)(2)(DMF)](BF4)(2).2DMF ( 1), [ Ag( tptz)(dppe)](n)(BF4)(n) .2nH(2)O.nMeOH ( 2), [Ag-2(tptz)(2)(dppp)(2)](BF4)(2) ( 3) and [Ag-2( tptz)(2)( dppb)](BF4)(2) ( 4) were obtained from the reactions of AgBF4 and diphosphine Ph2P(CH2)(n)PPh2 (L-pp, 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 [Ag-2(L-pp)(2)](2+) with double L-pp 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 pi-system.