Crystal structures and vibrational and solid-state (CPMAS) NMR spectroscopy of some bis(triphenylphosphine)silver(I) sulfate, selenate and phosphate systems

The crystal structures of [Ag-2(PPh3)(4)(EO4)]. 2H(2)O (E=S 1 or Se 2) showed that these contain [Ag-2(PPh3)(4)(EO4)] units with three-coordinate silver and EO42- bridging the two silver atoms via two oxygen atoms. The complexes [Ag(PPh3)(2)(HEO4)].H2O (E=S 3 or Se 4) contain [Ag(PPh3)(2)(HEO4)] molecules in which HEO4- is terminally bound to the silver atoms by a single oxygen atom. The complex [Ag(PPh3)(2)(H2PO4)]. 2EtOH 5 contains [Ag(PPh3)(2)(H2PO4)] molecules in which H2PO4- is terminally bound to the silver atom, which is essentially three-coordinate. Heteronuclear (1)J(Ag-107/109,P-31) and homonuclear (2)J(P-31,P-31) spin-spin coupling constants for these compounds were determined by analysis of their high- (9.40 T) and very high-field (17.62 T) P-31 CPMAS NMR spectra, with the aid of the 2-D P-31 CPCOSY technique, and a strong inverse correlation was found between (1)J(Ag-107/109,P-31) and the Ag-P bond length. IR and Raman studies show that the effect of a bound proton on the vibrational frequencies of EO42- is much greater than that of an attached metal atom.