Influence of a thioether function in short-bite diphosphine ligands on the nature of their silver complexes: Structure of a trinuclear complex and of a coordination polymer

摘要

New cationic Ag(i) complexes were prepared by reaction of AgBF_4 with two thioether-functionalized bis(diphenylphosphino)amine ligands, Ph _2PN(p-ArSMe)PPh_2 (L1) and Ph_2PN(n-PrSMe) PPh_2 (L2), and compared with those obtained from the unfunctionalized ligands Ph_2PN(Ph)PPh_2 (L3) and Ph_2PN(n-Bu) PPh_2 (L4), respectively. The complex [Ag_3(μ _3-Cl)_2(μ_2-L1-P,P)_3](BF _4) (1·BF_4) contains a triangular array of Ag centres supported by three bridging L1 ligands and two triply-bridging chlorides. In contrast, ligand L2 led to the coordination polymer [{Ag _2(μ_3-L2,-P,P,S)_2(MeCN)_2}{Ag _2(μ_2-L2-P,P)_2(MeCN)_2}(BF _4)_4]n (2) in which the tethered thioether group connects intermolecularly a Ag_2 unit to the diphosphine bridging the other Ag_2 unit. With L3 and L4, two similar complexes were obtained, [Ag_2(μ_2-L3)(BF_4)_2] (3) and [Ag_2(μ_2-L4)(BF_4)_2] (4), respectively, with bridging diphosphine ligands and a BF4 anion completing the coordination sphere of the metal. Complexes 1·BF _4·CH_2Cl_2, 2·THF, 3·3CH_2Cl_2 and 4 have been fully characterized, including by single crystal X-ray diffraction.