Crystal structures of two dioxomolybdenum complexes stabilized by salan ligands featuring phenyl and cyclo-hexyl backbones.

Two -dioxomolybdenum complexes based on salan ligands with different backbones are reported. The first complex, dioxido{2,2'-[l,2-phenyl-enebis(imino-methyl-ene)]bis-(phenolato)}molybdenum(VI) di-methyl-formamide disolvate, [Mo(CHNO)O]·2CHNO (LMoO, ), features a phenyl backbone, while the second complex, (6,6'-{[(cyclo-hexane-1,2-di-yl)bis(aza-nedi-yl)]bis-(methyl-ene)}bis-(2,4-di--butyl-phenolato))dioxidomolybdenum(VI) methanol disolvate, [Mo(CHNO)O]·2CHOH (LMoO, ), is based on a cyclo-hexyl backbone. These complexes crystallized as solvated species, ·2DMF and ·2MeOH. The salan ligands LH () and LH () coordinate to the molybdenum center in these complexes and in a κ ,κ fashion, forming a distorted octa-hedral geometry. The Mo-N and Mo-O distances are 2.3475 (16) and 1.9567 (16) Å, respectively, in while the corresponding measurements are Mo-N = 2.3412 (12) Å, and Mo-O = 1.9428 (10) Å for . A key geometrical feature is that the N-Mo-N angle of 72.40 (4)° in LMoO is slightly less than that of the LMoO angle of 75.18 (6)°, which is attributed to the flexibility of the cyclo-hexane ring between the nitro-gen as compared to the rigid phenyl ring in the LMoO.