Substitution reaction of triphenylphosphine oxide with rare-earth metal phosphido methyl complexes

Abstract

Rare-earth metal phosphido methyl complexes, [LLn(Me){P(H)Ar}] (L = [MeC{N(DIPP)}CHC(Me)(NCH₂CH₂NMe₂)]⁻, DIPP = 2,6-ⁱPr₂C₆H₃; 1: Ln = Sc, Ar = 2,4,6-^tBu₃C₆H₂; 2: Ln = Sc, Ar = 2,6-ⁱPr₂C₆H₃; 3: Ln = Sc, Ar = 2,6-Me₂C₆H₃; 4: Ln = Lu, Ar = 2,4,6-^tBu₃C₆H₂; 5: Ln = Lu, Ar = 2,6-ⁱPr₂C₆H₃), were synthesized and characterized. Complexes 1–5 reacted with triphenylphosphine oxide (Ph₃PO) to give [LLn(Ph){CH₂P(O)Ph₂}] (Ln = Sc(6), Lu(7)), by a mechanism that includes C(alkyl)–P bond formation and C(aryl)–P bond cleavage. The molecular structures of 1, 3 and 7 were determined by single-crystal X-ray diffraction. A pathway for the formation of 6 and 7 was suggested.