Cobalt(II) complexes based on (1-methyl-1<i>H</i>-benzo[<i>d</i>]imidazol-2-yl) methanol derivative: synthesis, crystal structure, spectroscopy, DFT calculations, and antioxidant activity

<p>In this paper, we present a combined experimental and computational study of two new cobalt(II) complexes as [Co(Hmbm)₂(OAc)₂] and [Co(Hmbm)₂(H₂O)₂]Cl₂ (Hmbm = (1-methyl-1<i>H</i>-benzo[<i>d</i>]imidazol-2-yl)methanol). Both complexes were characterized by FT-IR and UV–vis spectroscopy, elemental analysis, and single-crystal X-ray crystallography. The molecular geometries, electronic transitions, and vibrational frequencies of the two complexes and the ligand (Hmbm) in the ground state have been calculated using global hybrid (B3LYP) and range-separated hybrid (CAM-B3LYP) density functional. Qualitative description of excited states and charge transfer character of electronic transitions states were carried out by plotting the Natural Transition Orbitals (NTOs) for main states, and were assigned to LMCT. The ligand and its Co(II) complexes have been evaluated for their potential as DPPH radical scavengers.</p

Synthesis, X-ray structure, in silico calculation, and carbonic anhydrase inhibitory properties of benzylimidazole metal complexes

<p>Three coordination compounds of formula {M(bmim)₂Cl₂} were synthetised (M = Co, Zn, and Hg) and fully characterised. Each complex incorporates 1-benzyl-2-methylimidazole (bmim) as ligand. The coordination polyhedron around the metal center for all complexes has a quasi-regular tetragonal geometry. Density functional theory calculations were carried out on the title compounds and as well on hypothetical complexes (Cu, Ni), in order to elucidate their electronic and molecular structure. The calculations reproduced the Co, Zn, and Hg experimental structures and could predict stable complexes in the case of Ni(II) and Cu(II) ions. The carbonic anhydrase (CA, EC 4.2.1.1) inhibitory effects of the three complexes were investigated. Only compound {Hg(bmim)₂Cl₂} (<b>3</b>) exhibited a modest inhibitory effect against hCA I, probably due to the affinity of Hg(II) for His residues at the entrance of the active site cavity.</p