A new mono-functionalized organoimido hexa-molybdate derivative: bis-(tetra-n-butyl-ammonium) (5-chloro-2-methyl-phenyl-imido)-μ(6)-oxido-dodeca-μ(2)-oxido-penta-oxidohexa-molybdate(VI).

The title complex, [(C(4)H(9))(4)N](2)[Mo(6)(C(7)H(6)ClN)O(18)], was prepared by the reaction of (Bu(4)N)(4)[α-Mo(8)O(26)] and 2-methyl-5-chloro-aniline hydro-chloride with N,N'-dicyclo-hexyl-carbodiimide as dehydrating agent in dry acetonitrile solution. The aryl-imido ligand is linked to an Mo atom of the Lindqvist-type hexamolybdate anion by an Mo N triple bond, with a bond length of 1.732 (4) Å and an Mo N-C bond angle of 169.1 (4)°, typical for monodentate imido groups in such hybrid complexes. Due to the inter-action between one H atom in the aryl group and an O atom of a symmetry-related hexa-molybdate cluster, the anions form centrosymmetric dimers in the crystal structure. Weak C-H⋯O contacts are observed between the cations and anions. Unresolved disorder in some of the butyl chains of the ammonium cation is noted.