Synthesis, spectral, crystal structure, thermal behavior, antimicrobial and DNA cleavage potential of two octahedral cadmium complexes: A supramolecular structure

• Two new cadmium(II) complexes with general formula of CdL2X2 were synthesized.
• CdL2(NCS)2 crystallized in orthorhombic system with space group of Pbca.
• The C–H⋯π and C–H⋯S interactions in the CdL2(NCS)2 crystal caused a supramolecular structure.
• Cadmium complexes showed good antimicrobial activity against Gram positive and negative bacteria.
• The compounds showed good interaction with DNA.

Two new cadmium(II) complexes with the formula of CdL2(NCS)2 and CdL2(N3)2 (in which L is 2,2-dimethyl-N,N′-bis-(3-phenyl-allylidene)-propane-1,3-diamine) have been synthesized and characterized by elemental analysis, molar conductivity measurements, FT/IR, UV–Visible, 1H and 13C NMR spectra and X-ray studies. The crystal structure analysis of CdL2(NCS)2 indicated that it crystallizes in orthorhombic system with space group of Pbca. Two Schiff base ligands are bonded to cadmium(II) ion as N2-donor chelate. Coordination geometry around the cadmium ion was found to be partially distorted octahedron. The Cd–Nimine bond distances are found in the range of 2.363(2)–2.427(2) Å while the Cd–Nisothiocyanate bond distances are 2.287(2) Å and 2.310(2) Å. The existence of C–H⋯π and C–H⋯S interactions in the CdL2(NCS)2 crystal leads to a supramolecular structure in its network. Then cadmium complexes were screened in vitro for their antibacterial and antifungal activities against two Gram-negative and two Gram-positive bacteria and also against Candida albicans as a fungus. Moreover, the compounds were subjected for DNA-cleavage potential by gel electrophoresis method. Finally thermo-gravimetric analysis of the complexes was applied for thermal behavior studies and then some thermo-kinetics activation parameters were evaluated.

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