Synthesis, spectroscopic studies, X-ray crystal structures, electrochemical properties and DFT calculations of three Ni(II) complexes of aroyl hydrazone ligands bearing anthracene moiety

Co(III) and Ni(II) complexes of an anthracene appended aroyl hydrazone: Synthesis, crystal structures, DNA binding and catecholase activity

“…In the two complexes, the anthracene based transition around 400 nm is slightly blue-shifted and appears as a broad structured transition (Fig. 3) [10]. Weak broad bands at 938 and 915 nm along with weak shoulders at 671 and 553 nm for complexes 1 and 2 respectively are assigned to the d-d bands of the Co(III) and Ni(II) ions in a distorted octahedral environment (Fig.…”

“…The hydrazone ligand (E)-N-(anthracene-9-yl-methylene) benzohydrazide (L 2 H) was prepared following a procedure described earlier [10]. Anthracene 9-aldehyde was purchased from Aldrich.…”

“…TD-DFT calculations were performed on complex 2 to understand the nature of the transitions better. The results of the calculations, along with a comparison with the experimental data, (10) are presented in Table S3 in the SI. It can be seen from the table that there is reasonably good agreement between the experimental data and computed results.…”

“…The luminescence in 1 and 2 may be attributed to the anthracene based p ? p ⁄ emission [10,45] and the lower intensity of the fluorescence in the complexes compared to the ligand (CHEQ), often observed in octahedral transition metal complexes, is probably due to quenching by energy transfer pathways, because of the availability of a number of low-lying d-d energy levels in such an environment.…”

“…Aroyl hydrazones are quite interesting as they present a combination of donor sites, such as a protonated/deprotonated amide oxygen atom, imine nitrogen atom of the hydrazone moiety and an additional donor site (usually N or O) provided from the aldehyde or ketone forming the Schiff base [2][3][4]. Hydrazones form wide variety of complexes with chemical, structural, biological and industrial importance [2][3][4][5][6][7][8][9][10]. They have a variety of applications in biological and clinical fields, such as anti-bacterial, anti-fungal, anti-convulsing, anti-inflammatory, anti-malarial, analgesic, anti-platelets, anti-tuberculosis, anti-cancer and insecticidal activities [11][12][13][14][15][16][17].…”