Structural Exploration and Protein Binding Efficiencies of Binuclear Dioxidomolybdenum(VI) Complexes Constructed from ONO Chelator and Linear N−N Ditopic Spacer

• Published in: ChemistrySelect (Weinheim) 2022-08, Vol.7 (30), p.n/a
• Main Authors: Sarkar, Oiendrilla, Roy, Malini, Biswal, Debanjana, Ranjan Pramanik, Nikhil, Paul, Suvendu, Drew, Michael G. B., Chakrabarti, Syamal
• Format: Article
• Language: English
• Subjects: Bridging Ligand; DFT Calculation; Dioxidomolybdenum(VI); FRET; Protein Interactions; Schiff Bases; Supramolecular Architecture
• ISSN: 2365-6549; 2365-6549
• DOI: 10.1002/slct.202201412

This communication describes the syntheses, spectroscopic characterizations and crystal structures of two binuclear dioxidomolybdenum(VI) complexes 1 and 2 of general formula [MoO2L]2(N−N) with ONO donor ligands obtained by the condensation of benzoyl acetone with salicylhydrazide (H2L1) and anthranylhydrazide (H2L2) and spacer 1,2‐bis(4‐pyridyl)ethene (bpe). The crystal structures of these complexes have been solved by single crystal X‐ray crystallography. Both the complexes 1 and 2 are centrosymmetric and each Mo centre exhibits a distorted octahedral geometry. The complexes give rise to 3D supramolecular architectures with the formation of cavities via hydrogen bonding and C−H⋅⋅⋅π stacking interactions. Extensive DFT calculations are carried out to compare the structural parameters of the complexes with the experimental data and energy of frontier molecular orbitals are also calculated. The intermolecular interactions in the crystal structures are also studied by the Hirshfeld surface analysis. The redox behaviour of complexes has been examined by cyclic voltammetry. The binding affinity and binding mode of the complexes towards BSA has been explored by absorption and fluorescence titration method. Both the complexes exhibit fluorescence resonance energy transfer from protein to the complexes. The molecular docking investigations are also carried out to get a deeper insight into the binding mechanism. Binuclear dioxido Mo(VI) complexes(1 and 2) of general formula [(MoO2L1−2)2(bpe)] have been synthesized by varying a auxiliary bridging ligand on the primary ligand framework. The impact of spacer variation on metal‐organic supramolecular architectures, DFT calculations and BSA binding efficiencies of the complexes has been studied. The intermolecular interactions in the crystal structures are also studied by Hirshfeld surface analysis. FRET, Time‐resolved fluorescence measurement and molecular docking of the complexes were also carried out.