Abstract
A series of oxovanadium (IV) complexes namely, [Tp*VOL1], [Tp*VOL2], [Tp*VOL3], [Tp*VOL4] and [Tp*VOL5] (where Tp = hydrotris(3,5‐dimethylpyrazolyl)borate, HL1 = 1‐benzoyl‐3,3‐diethylthiourea, HL2 = 1‐(4‐chlorobenzoyl)‐3,3‐diethylthiourea, HL3 = 1,1‐diethyl‐3‐(4‐methoxybenzoyl)thiourea, HL4 = 1,1‐diethyl‐3‐(4‐nitrobenzoyl)thiourea, HL5 = N‐(diethylcarbamothioyl)biphenyl‐4‐carboxamide) were prepared and characterised on the basis of mass spectrometry, elemental analysis and spectroscopy techniques (IR, UV–Vis and electron paramagnetic resonance, EPR) and mass spectrometry. The crystal structure of [Tp*VOL3] was elucidated from single crystal X‐ray diffraction study and the crystals adopted a triclinic system with a P‐1 (Z = 2) space group and unit cell parameters of a = 10.4953(4), b = 11.5290(5) and c = 15.0656(7) Å. The cyclic voltammetry showed a reversible oxidation of V (IV)/V(V) at about 0.50 V (vs Fc+/Fc). The HOMO and LUMO of benzoylthiourea were established by theoretical calculation based on DFT level using B3LYP method and a double numeric plus polarisation (DNP) basis set. The in vitro tests for antimicrobial activity showed that the complexes have a moderate inhibitory effect. The complex [Tp*VOL1] exhibited cytotoxic activity against the human hepatocellular carcinoma cell line (HepG2) at the concentration of 20 mg ml−1. However, no cytotoxic activity was observed against the Chang liver cells.
A series of oxovanadium (IV) complexes were prepared and characterized on the basis of elemental analysis, IR, UV–Vis spectroscopy and electron paramagnetic resonance (EPR). In vitro tests of antimicrobial activity showed that all investigated complexes have moderate inhibitory effect. The HOMO and LUMO of benzoylthiourea were computed at DFT level. One of the prepared complexes exhibited cytotoxic activity against the human hepatocellular carcinoma cell line (HepG2) at high concentration.