Discrete mononuclear and dinuclear compounds containing a MoO22+ core and 4-aminobenzhydrazone ligands: synthesis, structure and organic-solvent-free epoxidation activity

摘要: Cyclic dinuclear molybdenum(vi) complexes [MoO2(L1–3)]2 (1, 2-α, 2-β and 3) were synthesized through the use of coordination-driven self-assembly a MoO22+ core 4-aminobenzoylhydrazone ligands (salicylaldehyde (H2L1), 3-methoxysalicylaldehyde (H2L2) or 4-methoxysalicylaldehyde (H2L3)). Their X-ray diffraction (XRD) analysis revealed that these types could serve as organic linkers for cis-octahedral containing core. Mononuclear [MoO2(L1–3)(MeOH)] (1a–3a) [MoO2(L1–3)(EtOH)] (1b, 2b-α, 2b-β 3b) also obtained. In presence strong donors, such dmf, ligand substitution occurred structures 1–3 changed into [MoO2(L1)(dmf)] (1c), [MoO2(L2)(dmf)] (2c) [MoO2(L3)(H2O)]·dmf (3c·dmf), respectively. The dioxidomolybdenum(VI) tested catalytic epoxidation cyclooctene under eco-friendly reaction conditions by using aqueous tert-butyl hydroperoxide (TBHP) an oxidant without addition solvent. present study showed much better activity catalysts than mononuclear ones due to weak donor properties amino group high geometric constraints occurring in small sized self-assembled systems confirmed density functional theory calculations.