Extending the coordination chemistry of molecular P4S3:: The polymeric Ag(P4S3)+ and Ag(P4S3)2+ cations

Upon reacting P4S3 with AgAl(hfiP)(4) and AgAl(pftb)(4) [hfip = OC(H)(CF3)(2); pftb = OC(CF3)(3)], the compounds Ag(P4S3)Al(hfiP)(4) 1 and Ag(P4S3)(2)(+)[Al(pftb)(4)](-) 2 formed in CS2 (1) or CS2/CH2Cl2 (2) solution. Compounds 1 and 2 were characterized by single-crystal X-ray structure determinations, Raman and solution NMR spectroscopy, and elemental analyses. One-dimensional chains of [Ag(P4S3)(x)](infinity) (x = 1, 1; x = 2, 2) formed in the solid state with P4S3 ligands that bridge through a 1,3-P,S, a 2,4-P,S, or a 3,4-P,P eta(1) coordination to the silver ions. Compound 2 with the least basic anion contains the first homoleptic metal-(P4S3) complex. Compounds 1 and 2 also include the long sought sulfur coordination of P4S3. Raman spectra of 1 and 2 were assigned on the basis of DFT calculations of related species. The influence of the silver coordination on the geometry of the P4S3 cage is discussed, additionally aided by DFT calculations. Consequences for the frequently observed degradation of the cage are suggested. An experimental silver ion affinity scale based on the solid-state structures of several weak Lewis acid base adducts of type (L)AgAl(hfiP)(4) is given, The affinity of the ligand L to the silver ion increases according to P-4 < CH2Cl2 < P4S3 < S-8 < 1,2-C2H4Cl2 < toluene.