Two new hydrogen-bonded supramolecular dioxo-molybdenum(VI) complexes based on acetyl-hydrazone ligands: Synthesis, crystal structure and DFT studies

Two new cis dioxomolybdenum(VI) complexes [MoO2L1(H2O)] (1) and [MoO2L2(H2O)] (2) have been synthesized using two different tridentate hydrazone Schiff base ligands, (LH2)-H-1[(E)-N'-(2-hydroxybenzylidene)acetohydrazide] and (LH2)-H-2 [(E)-N'-(2-hydroxy-3-methoxybenzylidene)acetohydrazide], respectively. The ligands and their corresponding Mo complexes are thoroughly characterized by different physicochemical techniques. Molecular structures of the complexes have been conclusively accomplished by single crystal X-ray diffraction. All the experimental findings reveal that both complexes have a distorted octahedral geometry around the Mo(VI) centre. The tridentate hydrazones coordinate to the metal centres in their enolic form in both 1 and 2. Hydrogen bonding and pi-pi interactions play an important role in the packing of the complexes in their solid state. Computational studies are also performed using DFT calculations at BP86-D3/def2-TZVP level of theory to understand the relative stability of the supramolecular networks. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Two new cis dioxomolybdenum(VI) complexes have been synthesized using two different tridentate hydrazone Schiff base ligands, characterized by physicochemical techniques and single crystal X-ray diffraction. The complexes exhibit a distorted octahedral geometry around the Mo(VI) centre, with the hydrazones coordinating to the metal centres in their enolic form and hydrogen bonding and pi-pi interactions playing important roles in the solid state packing. Computational studies were also conducted to understand the relative stability of the supramolecular networks.