New insights into the chemistry of oxomolybdenum(VI) complexes with N-salicylidene-2-aminoethanol

Abstract

Oxomolybdenum(VI) complexes with tridentate Schiff base, N-salicylidene-2-aminoethanol (H 2sae), has been synthesised by the reaction of Mo(O) 2(sal) 2 (where Hsal=salicylic aldehyde) with 2-aminoethanol. This reaction leads to dimeric [MoO(μ-O)(sae)] 2 and new monomeric [Mo(O) 2(sae){1,2-O (−)C 6H 4C(H)N (+)(H)C 2H 4OH}] ( 1) compounds. Also substitution of acetylacetonate ligand in Mo(O) 2(acac) 2 by H 2sae in EtOH leads to the same complexes (vide infra), but in MeOH monomeric compound Mo(O) 2(sae)(MeOH) ( 2) was formed. The molecular structure of complexes 1 and 2 have been determined by X-ray studies, which confirm that one of the H 2sae co-ordinates as η 3-tridentate O,N,O′ ligand, while in complex 1 this ligand exists also in zwitterionic form with intramolecular hydrogen bonding, O⋯HN, 2.584(3) Å, of phenolic oxygen bonded to the molybdenum atom. The crystals of 1 are triclinic, space group P 1 ̄ , a=8.483(2) Å, b=10.187(3) Å, c=11.034(3) Å, α=105.26(2)°, β=95.29(2)°, γ=95.10(2)°, and D calcd=1.666(1) g cm −3 for Z=2. The crystals of 2 are monoclinic, space group P2 1/ c, a=6.697(2) Å, b=7.375(2) Å, c=24.100(3) Å, β=92.76(5)°, and D calcd=1.805(1) g cm −3 for Z=4.