THE SYNTHESES AND VIBRATIONAL-SPECTRA OF BIS(CARBONYL)PLATINUM(II) FLUOROSULFATE, PT(CO)2(SO3F)2, AND BIS(CARBONYL)PALLADIUM(II) FLUOROSULFATE, PD(CO)2(SO3F)2

Reductive carbonylation of platinum(IV) tetrakis(fluorosulfate), Pt(SO3F)4, in fluorosulfuric acid at 80-degrees-C with a CO pressure of 1-2 atm resulted in the quantitative formation of creamy white bis(carbonyl)platinum(II) fluorosulfate, Pt(CO)2(SO3F)2. The corresponding bis(carbonyl)palladium(II) fluorosulfate, Pd(CO)2(SO3F)2, has been formed from solid Pd(II)Pd(IV)(SO3F)6 at room temperature and a CO pressure of 0.5 atm as a yellow solid that was thermally stable up to 117-degrees-C. Both compounds gave nearly identical IR and Raman spectra, which suggests a cis-square-planar configuration. The average CO stretching frequencies were at 2217 and 2201 cm-1 for Pd(CO)2(SO3F)2 and Pt(CO)2(SO3F)2, respectively. They are unusually high and suggest substantially reduced pi-back-donation. Pd(CO)2(SO3F)2 is the first example of a thermally stable mononuclear bis(carbonyl) derivative of dipositive palladium.