Samarium hydride, methyl, and vinyl complexes supported by calix-tetrapyrrole ring macrocycle. Thermal decomposition to samarium(II)

Trivalent methyl and vinyl samarium derivatives supported by the calix-tetr apyrrole Ligand system (Ets-calix-pyrrole) (R)Sm(mu(3)-Cl)[Li(THF)](2)[Li(T HF)(2)] [R = Me (2a), CH=CH2 (2b)] were prepared via reaction of (Et-8-cali x-pyrrole)(Cl)Sm[Li-2(THF)(3)] (1) with the corresponding organolithium rea gent. Complex 2a reacts readily with Hz at room temperature and atmospheric pressure to afford the corresponding samarium hydride (Et-8-calix-pyrrole) (THF)Sm[Li(THF)](2)(mu(3)-H) (3). Complexes 2a and 3 are thermally robust. Conversely, the vinyl derivative 2b rapidly and spontaneously decomposes at room temperature to afford the Sm-II derivative (Et-8-calix-pyrrole)(THF)S m[Li(THF)](2)[Li(THF)(2)](mu(3)-Cl) (4a).