Properties of [Pd2X2(dppm)2] (X = Cl, SnCl3, dppm = Bis(diphenylphosphino)methane) Complexes on Porous Vycor Glass

Abstract

Porous Vycor glass (PVG) is used as a matrix for immobilization of complexes containing metal-metal bonds: [Pd2Cl2(dppm) 2], [Pd2(SnCl3)Cl(dppm)2] and [Pd2(SnCl3)2(dppm)2]. The high reactivity of the metal-metal bonds in insertion reactions with small molecules such as CO and SO2 is preserved in the pore medium, and is reversible under vacuum. 31P MAS-NMR and Raman spectra indicate that there is a range of interactions between the glass and the adsorbed molecules as a result of the availability of different groups in the molecules and of the irregular pore topology as well. The static character of the molecules in the restrictive pore environment precludes motions such as flipping of the ring Pd 2P4C2 between boat and chair conformations and rotation of the phenyl rings, and the molecules may present a range of conformations.