Pyrrolylaldiminato Complexes of Zn, Mg and Al

Abstract

The reaction of 2-(2,6-iPr2C6H3N=CH)-5-R-C4H2NH (R = H, L1H; R = tBu, L2H) with one equivalent of ZnMe2 or MgnBu2 in toluene or n-hexane afforded the bis(pyrrolylaldiminato) complexes ZnL12 (1), ZnL22 (2) and MgL22 (3). Crystalline MgL12·THF (4·THF) was formed by treatment of LiL1 with MeMgCl in THF followed by recrystallization from n-hexane. L1AlMe2 (6) and L2AlMe2 (7) were readily prepared by refluxing L1H and L2H with AlMe3 in toluene or n-hexane for several hours. However, the reaction of LiL1 with AlCl3 in a 1:1 molar ratio provided L12AlCl (8), while the reaction of KL2 with AlCl3 afforded L2AlCl2 (9). Compounds 2, 3, 5, and 8 were characterized by a single-crystal X-ray structural analysis. Compounds 2, 3, and 5 all have a tetrahedral geometry around the metal atom, while the five-coordinate aluminum in 8 has a trigonal bipyramidal geometry. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)