Lanthanoid Biphenolates as a Rich Source of Lanthanoid-Main Group Heterobimetallic Complexes.

Abstract

Several new trivalent dinuclear rare earth 2,2’‐methylenebis(6‐tert‐butyl‐4‐methylphenolate) (mbmp2−) complexes with the general form [Ln2(mbmp)3(thf)n] (Ln=Sm 1, Tb 2 (n=3), and Ho 3, Yb 4 (n=2), and a tetravalent cerium complex [Ce(mbmp)2(thf)2] (5) have been synthesised by RTP (redox transmetallation/protolysis) reactions from lanthanoid metals, Hg(C6F5)2 and the biphenol mbmpH2. These new complexes and some previously reported partially protonated rare earth biphenolate complexes [Ln(mbmp)(mbmpH)(thf)n] react with lithium, aluminium, potassium and zinc organometallic reagents to form lanthanoid‐main group heterobimetallic species. When reaction mixtures containing the Ln biphenolate complexes were treated with n‐butyllithium, both molecular ([Li(thf)2Ln(mbmp)2(thf)n] (Ln=La 6, Pr 7 (n=2) and Er 8, Yb 9, and Lu 10 (n=1)) and charge separated ([Li(thf)4][Ln(mbmp)2(thf)2] (Ln=Y 11, Sm 12, Dy 13, and Ho 14) complexes were isolated. Treatment with trimethylaluminium also led to isolation of molecular ([AlMe2Ln(mbmp)2(thf)2] (Ln=Pr 15, Sm 16, and Tb 17)) and ionic [La(mbmp)(thf)5][AlMe2(mbmp)] (18) complexes. One gadolinium‐potassium ([K(thf)3Gd(mbmp)2(thf)2] (19)), and one ytterbium‐zinc species ([ZnEtYb(mbmp)2(thf)] (20)) were isolated from treatment of reaction mixtures with potassium bis(trimethylsilyl)amide and diethylzinc respectively.