Synthesis and X-ray Crystal Structures of β-Ketoiminate Complexes

Heteroleptic zinc complexes containing side-arm donor-functionalized tridentate beta-ketoiminate ligands were obtained from metalation reactions of beta-ketoimines L1/2/3(Do1/2/3/4)H [L1 = {(OC(Me)C(H)C(Me)NCH(2)CH(2)Do)}, L2 = {(OC(Me)C(H)C(Me)NCH(2)CH(2)CH(2)Do)}, L3 = {(OC(OMe)C(H)C(Me)NCH(2)CH(2)Do)}; Do1 = NMe2, Do2 = NEt2; Do3 = Pyr, Do4 = OMe] with equimolar amounts of Zn[N(SiMe3)(2)](2) [L1(Do1)ZnN(SiMe3)(2) (1), L1(Do2)ZnN(SiMe3)(2) (2)] and ZnEt2 [L1(Do3)ZnEt (3), L2(Do3)ZnEt (4), L3(Do1)ZnEt (5), L3(Do4)ZnEt (6)]. Analogous reactions of AlMe3 and Cp*MMe3 with L1(Do1/2)H yielded homoleptic aluminum [L1(Do1)AlMe(2) (7), L1(Do2)AlMe(2) (8), L2(Do1)AlMe(2) (9)], titanium [L1(Do2)Ti(Me-2)Cp* (10)] and zirconium complexes [L1(Do2)Zr(Me-2)Cp* (11)]. In addition, 7 reacts with an ethereal HCl solution with methane elimination and formation of L1(Do1)Al(Cl)Me (12) and L1(Do1)AlCl(2) (13), whereas the reaction with one and two equivalents of 2,6-dimethylphenol yielded L1(Do1)Al(Me)O-2,6-Me2C6H3 (14) and L1(Do1)Al(O-2,6-Me2C6H3)(2) (15). The complexes were characterized by elemental analysis, H-1, C-13 NMR, and IR spectroscopy and single-crystal X-ray analysis (2, 4, 7, 10, 12-14).