BIMETALLIC MIXED-METAL COMPLEXES OF THE SALEN(BU-T) LIGANDS

The Salen(Bu-t) ligands, Salen(Bu-t), N'-ethylenebis(3,5-di-tert-butyl salicylideneimine) and Salpen(Bu-t), '-propylenebis(3,5-di-tert-butyls alicylideneimine) can be combined with GaEt3 to prepare the 'open' mon ometallic compounds, Salen(Bu-t)H(GaEt2) (1) and Salpen(Bu-t)(GaEt2) ( 2). These, in turn, can be converted to the bimetallic derivatives, Sa len(t)Bu(GaEt2)(2) (3) and Salpen(Bu-t)(GaEt2)(2) (4) by addition of G aEt3. Alternatively, 3 and 4 can be made by the addition of two moles of GaEt3 to the appropriate ligand. This was the method used to prepar e Salben(Bu-t)(GaEt2)(2) (5) (Salben(Bu-t) = N'-butylenebis(3,5-di-ter t-butylsalicylideneimine) and Salhen(Bu-t)(GaEt2)(0) (6) [Salhen(Bu-t) = '-hexylenebis(3,5-di-tert-butylsalicylideneimine]. Compounds 1 and 2 can be utilized to form the unique mixed-metal derivatives L(GaEt2) (MR2) (where L = Salen(Bu-t), M : R = Al, Me (7); Al, Et (9); and L = Salpen(Bu-t), M: R = Al, Me (8); Al, Et (10). At ambient temperatures in non-polar solvents, 7-12 do not undergo exchange of either the alky l or MR2 groups. All of the compounds were characterized by Mp, analys es, H-1 NMR, IR and, in the case of 1 and 3-6, by X-ray crystallograph y. (C) 1998 Elsevier Science Ltd. All rights reserved.