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p ‐Toluate‐bridged dinuclear Cu(II) complexes in combination with tridentate chelating ligand: Crystal structure, density functional theory calculation, DNA/protein binding and catecholase activity
Author(s) -
Dolai Samar,
Das Kalipada,
Bhunia Apurba,
Bertolasi Valerio,
Manna Subal Chandra
Publication year - 2018
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.4506
Subject(s) - chemistry , schiff base , density functional theory , human serum albumin , ligand (biochemistry) , chelation , crystal structure , crystallography , bovine serum albumin , square pyramidal molecular geometry , stereochemistry , inorganic chemistry , computational chemistry , receptor , biochemistry , chromatography
The dinuclear Cu(II) complexes [Cu 2 (L 1 ) 2 (mb)]⋅ClO 4 ( 1 ) and [Cu 2 (L 2 ) 2 (mb)]⋅ClO 4 ( 2 ) (HL 1 = 2‐[(2‐diethylaminoethylimino)methyl]phenol; HL 2 = 2‐[1‐(2‐diethylaminoethylimino)propyl]phenol; mb = 4‐methylbenzoate) were synthesized and characterized using X‐ray crystal structure analysis and spectroscopic methods. Complexes 1 and 2 are dinuclear with distorted square pyramidal Cu (II) geometries, where Schiff base coordinates with tridentate (N,N,O) chelating mode and mb bridges two metal centres. Optimized structures and photophysical properties of ligands and complexes were calculated using density functional theory and time‐dependent density functional theory methods using B3LYP functional with 6‐31G (d,p) and LanL2MB basis sets. Interactions of the complexes with bovine serum albumin (BSA) and human serum albumin (HSA) were studied using UV–visible absorption and fluorescence spectroscopies and the calculated values of association constants (M −1 ) are 1.7 × 10 5 ( 1 –BSA), 5.7 × 10 5 ( 2 –BSA), 1.6 × 10 5 ( 1 –HSA) and 6.9 × 10 5 ( 2 –HSA). Interactions of the complexes with calf thymus DNA were also investigated and the binding affinities are 1.4 × 10 5 and 1.6 × 10 5 M −1 for 1 and 2 , respectively. Both complexes catalytically oxidize 3,5‐di‐ tert ‐butylcatechol to 3,5‐di‐ tert ‐butylbenzoquinone in the presence of molecular oxygen.