NaPdPS 4 and RbPdPS 4: systems with infinite straight [formula omitted][PdPS 4] − chains soluble in polar solvents and the structure of cubic RbPdPS 4{Rb 0.33P 0.4S 2.23O x}

Abstract

The synthesis, crystal structures, chemical and spectroscopic properties of NaPdPS 4, RbPdPS 4, and RbPdPS 4{Rb 0.33P 0.4S 2.23O x } are described. NaPdPS 4, RbPdPS 4, are isostructural and crystallize in the tetragonal system I4/ mcm with cell parameters a=7.3074(8) Å, c=12.2308(14) Å and a=8.2954(3) Å, c=12.2284(4) Å respectively. RbPdPS 4{Rb 0.33P 0.4S 2.23O x } is cubic, space group Pm-3 n and a=12.0042(2) Å. All compounds contain the same 1 ∞ [PdPS 4] − chains made of alternating square planar Pd 2+ cations and tetrahedral [PS 4] 3− anions. RbPdPS 4{Rb 0.33P 0.4S 2.23O x } contains co-crystallized highly disordered molecular species encapsulated within [Rb 8] cubic cavities. Spectroscopic solid state 31P NMR, infrared and Raman data as well as elemental analysis suggest that these species could be S n 2− ( n=3 or 4) anions and possibly cationic [P 4S 6O] 6+ fragments. NaPdPS 4 and RbPdPS 4 exhibit exfoliative dissolution in polar solvents giving rise to solutions that show signs of complex fluid behavior.