Trinuclear polyoxomolybdates, the crystal and molecular structure of [(n-C 4H 9) 4N][Mo 3O 6(OCH 2CH 2Cl){(OCH 2) 3CCH 3} 2

Abstract

The reaction of [(n-C 4H 9) 4N] 4[Mo 8O 26] with 2-(hydroxymethyl)-2-methyl-l,3-propanediol (H3hmmp) in acetonitrile yields (TBA) 2[Mo 3O 7(hmmp) 2] ( 1). Complex 1 reacts with chloroacetic acid and alkylating agents to yield the derivatives (TBA)[Mo 3O 6(OH)(hmmp) 2] ( 2) and (TBA)[Mo 3O 6(OR)(hmmp) 2] ( 3), respectively. The direct reaction of (TBA) 4[Mo 8O 26] with H 3hmmp in chloroethanol yields (TBA)[Mo 3O 6(OCH 2CH 2Cl)(hmmp) 2 ( 4). The structure of 4 consists of discrete trinuclear anions [Mo 3O 6(OCH 2CH 2Cl)(hmmp) 2] - and TBA + cations. Two of the molybdenum centers exhibit similar coordination environments, each bonding to two terminal oxo groups, one terminal hmmp alkoxy donor and three bridging alkoxy, oxygens from the hmmp ligands. The third molybdenum center coordinates to two terminal oxo groups, a terminal chloroethanolate ligand, and three bridging alkoxy oxygens of the hmmp ligands. Crystal data: monoclinic space group P2 1/ n, a=12.224(2), b=23.178(3), c=13.562(3) Å, β= 97.05(1)°, V=3813.1(11) Å 3, Z=4. Structure solution and refinement based on 4794 reflections (Mo Kα, λ=0.71073 Å, 2θ⩽45°) converged at a conventional discrepancy value of 0.052.