SYNTHESIS, MOLECULAR-STRUCTURE, AND VIBRATIONAL-SPECTRA OF CYCLO-BIS(MU-CARBONYL)DIPALLADIUM(I) FLUOROSULFATE, [C-PD2(MU-CO)2](SO3F)2

The synthesis, molecular structure, and complete vibrational spectrum of cyclo-bis(mu-carbonyl)dipalladium(I) fluorosulfate, [c-Pd2(mu-CO)2] (SO3F)2, are reported. The synthesis is achieved by reductive decompo sition of Pd-(CO)2(SO3F)2 in fluorosulfuric acid, HSO3F; at 25-degrees -C, long orange-red needles form over a period of about 3 weeks. The c ompound is stable up to 157-degrees-C (the decomposition point). The m olecular structure is solved by single-crystal X-ray diffraction. Crys tals of [Pd2(mu-CO)2](SO3F)2 are monoclinic, C2/c; a = 11.495(1), b = 8.255(1), and c = 9.556(1) alpha; beta = 91.94(1)degrees; Z = 8. The s tructure is solved by the Patterson method and is refined by full-matr ix least-squares procedures to R = 0.061 and R(w) = 0.075 for 2667 ref lections with I greater-than-or-equal-to 3sigma(I). The structure reve als planar [Pd2(mu-CO)2]2+ cations formed by two nearly symmetrically CO-bridged palladium atoms, linked by bidentate-bridging fluorosulfate anions into a polymeric sheet. The vibrational spectrum using FT-IR a nd FT-Raman spectroscopy down to 50 cm-1 is interpreted in terms of D2 h symmetry for the molecular cation, and 10 of the expected 12 fundame ntal vibrations are detected and assigned. The vibrational spectrum fe atures the highest CO stretching frequency (nuBAR(CO)av = 2002 cm-1) s o far reported for a bidentate-bridging CO ligand in metal-carbonyl ch emistry.