Reactions of polyoxomolybdates with oximes. The crystal and molecular structures of [(C 4H 9) 4N] 2[Mo 2O 5C 6H 4(O)CHNO 2] · CH 2Cl 2 and [(C 4H 9) 4N] 2[Mo 2O 5C 6H 5CH(O)C(NO)C 6H 52

Abstract

The reactions of [(C 4H 9) 4N] 2[Mo 2O 7] with the oximes benzoinoxime and salicylaldoxime yielded the complexes [(C 4H 9) 4N] 2[Mo 2O 5C 6H 4(O)CHNO 2] · CH 2CI 2(7) and [(C 4H 9) 4N] 2[Mo 2O 5C 6H 5CH(O)C(NO)C 6H 5 2] (8). The structures of 7 and 8 exhibit the [Mo 2O 5] 2+ core with the oximato moieties of the ligands functioning as μ 2-O,N bridging donors. The metrical parameters are consistent with the sp 2 hybridization of the oximato nitrogen with double bond character localized on the C N bond. Crystal data: Compound 7, monoclinic space group, P2 1/ c, a = 16.271(6), b = 14.010(4), c = 25.390(8) Å, β = 101.34(2)°, V = 5672.9(19) Å 3, D calc = 1.30 g cm −3 for Z = 4. Structure solution and refinement based on 4718 reflections with F o ⩾ 6 σ( F o)(Mo- K α , λ = 0.71073 Å) converged at a conventional residual of 0.064. Compound 8, rhombohedral space group (hexagonal setting) R 3 ¯ , a = b = 47.188(14), c = 15.766(3) Å, V = 30403.4(27) Å 3, D calc = 1.19 g cm −3 for Z = 18. Structure solution and refinement based on 3015 reflections with F o ⩾ 6 σ( F o) converged at a value of 0.069 for the conventional R factor. Reaction of the related salicylhydroxamic acid with [(C 4H 9) 4N] 2[Mo 2O 7] in methanol yielded the complex [(C 4H 9) 4N][MoO 2C 6H 4(OH)C(O)NOC 6H 4(OH)C(O)NHO] (11), a species exhibiting both hydroximato(2−) and hydroxamato(1−) forms of the ligand. Crystal data: Compound 11, monoclinic space group P2 1/ c, a = 10.261(2), b = 17.864(4), c = 18.270(3) Å, β = 91.98(1)°, V = 3347.0(10) Å 3, D calc = 1.34 g cm −3 for Z = 4. Structure solution and refinement based on 3406 reflections converged at a value of 0.049 for the conventional R factor.