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

Oxomolybdenum(VI) complexes with tridentate Schiff base, N-salicylidene-2-aminoethanol (H(2)sae), 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(mu-O)(sae)](2) and new monomeric [Mo(O)(2)(sae){1,2-O(-)C6H4C(H)N(+)(H)C2H4OH}] (1) compounds. Also substitution of acetylacetonate ligand in Mo(O)(2)(acac)(2) by H(2)sae 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,sae co-ordinates as eta(3)-tridentate O,N,O' ligand, while in complex I this ligand exists also in zwitterionic form with intramolecular hydrogen bonding, (OH)-H-...-N, 2.584(3) Angstrom, of phenolic oxygen bonded to the molybdenum atom. The crystals of 1 are triclinic, space group P (1) over bar, a = 8.483(2) Angstrom, b = 10.187(3) Angstrom, c = 11.034(3) Angstrom, alpha = 105.26(2)degrees, beta = 95.29(2)degrees, gamma = 95.10(2)degrees, 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) Angstrom, b = 7.375(2) Angstrom, c = 24.100(3) Angstrom, beta = 92.76(5)degrees, and D-calcd = 1.805(1) g cm(-3) for Z = 4. (C) 2003 Elsevier B.V. All rights reserved.