VARIABLE-TEMPERATURE C-13 SOLID-STATE NMR-SPECTRA - MOBILITY OF TRIMETHYLTIN GROUPS IN COORDINATION POLYMERS OF THE TYPE [(ME3SN)4M(CN)6]INFINITY (M=FE, OS, RU)

Solid-state C-13 CP MAS NMR studies of compounds [(Me3Sn)4M(CN)6]infinity with M=Fe, Ru and Os were performed over a temperature range of 80 K in order to understand exchange thermodynamics. For each compound six methyl carbon signals are seen below 240 K, showing there are two non-equivalent Me3Sn units. Using detailed lineshape analysis the thermodynamic activation parameters for the three samples were obtained. Low-temperature 2-D exchange spectra indicated that exchange occurs between the carbons of each Me3Sn rotor independently. Therefore in the calculations a model of two independent three-site mutual-exchange processes was used. The effect of Sn-117/Sn-119 satellites was included.