Dinuclear Complexes of Di-, Tri-, and Mixed-Valent Samarium Supported by the Calix-tetrpyrrole Ligand

摘要

SmCl_3(THF)_3 reacts with 1/2 equiv of (Et_8-calix-pyrrole)[Li(ThF)]_4 to yield the dinuclear, trivalent complex (Et_8-calix-pyrrole)Sm_2{(#mu#-Cl)_2[Li(THF)_2]}_2 (1). This species underoges alkylation in diethyl ehter resulting in the formation of the nearly isostructural (Et_8-calix-pyrrole)Sm_2{(#mu#-CH_3)_2[Li(THF)_2]}_2 (2) Complex 1 is reduced by LiAiH_4 to produce either the mixed-valence (Et_8-calix-pyrrole)Sm_2(THF)_2(#mu#-Cl)_2[Li(THF)_2](3) or the divalent (Et_8-calix-pyrrole)Sm_2(THF)_4(4), depending on the reaction conditions empoyed. The alkyl compound 2 reacts with PhSiH_3 in THF, resulting in a complex mixture of products, form which a mixture of the trivalent, mononuclear hydride (Et_8-calix-pyrrole)(THF)Sm(#mu#-H)Li_2[LiOCH=CH_2]_2(THF)_2 (5) and (Et_8-calix-pyrrole)Sm(H)Li_2(THF)_6 (6) were isolated in modest yield. The structures of 1-5 were elucidated by X-ray crystallography.