Magnesium, zinc and aluminium complexes supported by tripodal diaminebis(aryloxido) ligands: Synthesis, solid state and solution structure

Abstract

The reactions of the diaminebis(aryloxido) ligand precursors [Me 2 NCH 2 CH 2 N(CH 2 -4-R-C 6 H 3 OH) 2 ] [R = C(CH 3) 2 CH 2 C(CH 3) 3, H 2 L 1; R = CH 3, H 2 L 2 ] with Mg n Bu 2, ZnEt 2 and AlEt 3 create complexes of general formula [M 2 (μ-L-κ 4 O,N,N,O) 2 ] (M = Mg, 1a for L 1 and 1b for L 2; M = Zn, 2a for L 1 and 2b for L 2) and [Al 2 (μ-L- κ 3 O,N,N,O) 2 Et 2 ] (3 for L 1) in good yields. Compounds 1a-3 were characterized by NMR spectroscopy and ESI-MS experiments. The definitive molecular structure of 1b·CH 2 Cl 2, 2a·H 2 O, 2b·CH 2 Cl 2 and 3 was provided by a single-crystal analysis and revealed their dimeric nature with an M 2 O 2 planar core. The L 1 and L 2 ligands coordinate as the dianions in a tetradentate/bridging manner in 1b, 2a, 2b and in a tridentate/bridging mode in 3. The NMR spectra showed that the solid state of these compounds is essentially retained in solution. © The Royal Society of Chemistry 2013.