An unexpected entry into the silver(I) chemistry of diphosphazane ligands: Crystal and molecular structures of [Ag{Ph2PN(Pri)PPh2}(CF3SO3)]2, [Ag{Ph2PN(Pri)PPh(OC6H3Me2-2,6)}2]PF6, and [Ag3(μ-Cl)2{Ph2PN(R)PPh2}3]PF6 (R = H, Pri)

Mononuclear, binuclear and trinuclear silver(I) complexes were obtained unexpectedly while probing the reactivity of diphosphazane ligands of the type X2PN(Pri)PXY towards the ruthenium-based precursor Ru(bipy)2Cl2 · 2H2O, in the presence of a silver salt as a chloride scavenger. Subsequently, the reactions of AgX [X = Cl, NO3 or CF3SO3] with Ph2PN(R)PPh(Y) [R = H, Y = Ph; R = Pri, Y = Ph or OC6H3Me2-2, 6] in a 1:1 or 1:2 molar ratio have been investigated. Mononuclear or binuclear Ag(I) complexes containing either chelating or bridging diphosphazane ligands are obtained. Trinuclear silver(I) complexes are accessible by the treatment of diphosphazane ligands, Ph2PN(R)PPh2 [R = H, Pri] with AgCl using piperidine as the solvent. In the presence of a suitable chloride donor species, the mononuclear and binuclear complexes of Ph2PN(Pri)PPh2 are transformed slowly to the trinuclear complex [Ag3(μ-Cl)2{Ph2PN(Pri)PPh2}3]X, over a period 20 h. The structures of representative complexes have been confirmed by X-ray crystallography and the salient structural features are discussed.

Graphical abstractThe reactions of AgX (X = Cl, NO3 or CF3SO3) with diphosphazane ligands of the type X2PN(R)PXY give mononuclear, binuclear and trinuclear silver(I) complexes which exhibit different coordination numbers and geometries as revealed by single crystal X-ray diffraction studies.Figure optionsDownload full-size imageDownload as PowerPoint slide