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-tetrapyrrole ligand system (Et 8 -calix-pyrrole)(R)Sm(μ 3 -Cl)[Li(THF)] 2 [Li(THF) 2 ] [R = Me ( 2a ), CH CH 2 ( 2b )] were prepared via reaction of (Et 8 -calix-pyrrole)(Cl)Sm[Li 2 (THF) 3 ] ( 1 ) with the corresponding organolithium reagent. Complex 2a reacts readily with H 2 at room temperature and atmospheric pressure to afford the corresponding samarium hydride (Et 8 -calix-pyrrole)(THF)Sm[Li(THF)] 2 (μ 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)Sm[Li(THF)] 2 [Li(THF) 2 ](μ 3 -Cl) ( 4a ).