Note First example of a borate-bridged dimeric aluminum Schiff-base complex containing five-coordinate metal centers

The formation of a borate-bridged dimeric aluminum Schiff-base compound [salen(Bu)Al]2O2BOMe [salen=N,N’-ethylenebis(salicylidenimine) (1) has been reported. Complex 1 crystallizes in a triclinic P space group with a=14.57, b=15.15, c=15.84 Å and a=96.92, b=90.82, g=105.538. The crystal structure shows the presence of a metaborate (MeOBO2 2– ) bridge between two five-coordinate aluminum atoms with a bridging OBO angle of 123.258. The compound has been characterized by H, C, B, Al NMR, IR and mass spectroscopies and melting point measurements. H NMR shows two complex multiplets for the Bu groups and two different environments for the imine protons. B NMR shows a peak at 18 ppm characteristic of three-coordinate boron and Al NMR shows a peak at 29 ppm characteristic of five-coordinate aluminum.