Re(I) carbonyl complexes of N-[(2-pyridyl)methyliden]-α (or β)-aminonaphthalene: Synthesis, structure, electrochemistry and DFT analysis

The article deals with a combined experimental and computational study of rhenium tricarbonyl Schiff base complexes having general formula fac-[ReCl(CO)3(L1/L2)] (1/2) (L1 = N-[(2-pyridyl)methyliden]-α-aminonaphthalene and L2 = N-[(2-pyridyl)methyliden]-β-aminonaphthalene). The complexes fac-[ReCl(CO)3(L1/L2)] (1/2) have been synthesized and characterized by elemental analysis, spectroscopic studies, electrochemistry and X-ray crystal analysis for complex 2. Crystal structure of 2 reveals the facial geometry of the carbonyl ligand and Re is in distorted octahedral environment in the complex. The electronic structure, redox properties, absorption and emission properties have been explained based on DFT and TDDFT calculations. The complexes show MLCT bands at 395–405 nm and emitted at 425–435 nm upon excitation at 310 nm, characterized as ILCT transitions. The complexes exhibit two irreversible ReII/ReI and ReIII/ReII oxidative responses when scanned in the potential range 0.0–2.0 V in cyclic voltammetric studies.