Complexes of N-(2-thiazolyl)-1H-benzotriazole-1-carbothioamide with Pd(II), Pt(II), and Zn(II): Spectral, DFT, cytotoxicity and anti-angiogenic effect on MCF-7 cell line

•Different coordination modes toward metal ions were found.•The studied complexes are useful to suppress the breast cancer metastasis.•Ionic nature of Pd(II) complex made it more toxic than other compounds.•ELUMO, ΔE, dipole moment and polarizability correlate well with IC50.

[ZnL2]·4EtOH (1), [PdL(EtOH)2]·Cl (2) and [PtL(EtOH)Cl] (3) (HL = N-(2-thiazolyl)-1H-benzotriazole-1-carbothioamide complexes have been synthesized, and characterized by elemental analysis, IR, 1H NMR, UV–Vis, and TGA. In complex 1, the thiazole N and C–S− donor sites of two deprotonated ligand molecules are coordinated to Zn(II) forming a tetrahedral structure, while in case of 2 and 3, the benzotriazole N and C–S− are participated in the coordination spheres of square planar complexes. Optimized structures, natural bond orbital analysis, molecular electrostatic potential maps, and frontier molecular orbitals have been obtained by DFT/B3LYP/LANL2DZ method. Time-dependent DFT calculations have been performed to assign the electronic spectra. The complexes in comparison to HL have been screened for their antimicrobial and cytotoxicity activities. Complex 2 (3.08 μg/mL) is more potent than HL and the other complexes that may be attributed to its ionic nature and presence of two easily replaceable ethanol molecules. The capacity of complexes to slow down the proliferation of the MCF7 cell line has been achieved by down regulation of the vascular endothelial growth factors using RT-PCR technique.

Graphical abstractThe investigated complexes are useful to suppress the breast cancer metastasis. Different coordination modes were observed. The highest cytotoxicity of the Pd(II) complex is attributed to its ionic nature. SAR has been also used to correlate the IC50 values with some quantum descriptors.Figure optionsDownload full-size imageDownload as PowerPoint slide