X-ray structures, spectroscopic, electrochemical, thermal, antibacterial, and DFT studies of two nickel(II) and cobalt(III) complexes constructed from a new quinazoline-type ligand

Two two-dimensional supramolecular Nickel(II) and Cobalt(III) complexes, [Ni(L-2)(2)]2CH(3)OH (1) and [2Co(L-2)(2)] (2) (HL2=1-(2-{[(E)-3-bromo-5-chloro-2-hydroxybenzylidene]amino}phenyl)ethanone oxime), were synthesized via complexation of salts acetate with HL1 (2-(3-bromo-5-chloro-2-hydroxyphenyl)-4-methyl-1,2-dihydroquinazoline 3-oxide, H is the deprotonatable hydrogen). During the reaction, the C-N bond in HL1 is converted into the C=N-OH group in HL2. The spectroscopic data of both complexes were compared with the ligand HL1. HL1 and both complexes were determined by single-crystal X-ray crystallography. The differently geometric features of the obtained complexes 1 and 2 are observed. In the crystal structure, 1 and 2 form an infinite 1-D chain-like and 2-D supramolecular frameworks. EPR spectroscopy of 2 was investigated. Moreover, electrochemical properties and antimicrobial activities of both complexes were also studied. In addition, the calculated HOMO and LUMO energies show the character of HL1, complexes 1 and 2. The electronic transitions and spectral features of HL1 and both complexes were discussed by TD-DFT calculations.