Synthesis,characterization, density functional theory studies and antibacterial activity of a new Schiff base dioxomolybdenum(VI) complex with tryptophan as epoxidation catalyst

A cis ‐dioxomolybdenum(VI) complex was prepared with MoO₂(acac)₂ and a Schiff base ligand (2‐((2‐hydroxybenzylidene)amino)‐3‐(1H ‐indol‐3‐yl)propanoic acid) derived from salicylaldehyde and l ‐tryptophan in ethanol and designated as [MoO₂(Sal‐Tryp)(EtOH)]. It was characterized using several techniques including thermogravimetric and elemental analyses and mass, Fourier transform infrared and UV–visible spectroscopies. Theoretical calculations were performed using density functional theory for studying the molecular structure. An in vitro antibacterial activity evaluation showed that [MoO₂(Sal‐Tryp)EtOH] complex exhibits good inhibitory effects against Gram‐positive (Bacillus subtilis , Staphylococcus aureus ) and Gram‐negative (Escherichia coli , Pseudomonas aeruginosa ) bacteria in comparison to standard antibacterial drugs. It was also found that [MoO₂(Sal‐Tryp)EtOH] complex successfully catalyses the epoxidation of cyclooctene, norbornene, cyclohexene, styrene, α‐methylstyrene and trans ‐stilbene, with 45–100% conversions and 64–100% selectivities. Based on the obtained results, the heterogeneity and reusability of the catalyst seem promising.