Coordination chemistry of rare earth metal complexes with coumarin-based imines: ecofriendly synthesis, characterization, antimicrobial, DNA cleavage, pesticidal, and nematicidal activity evaluations

Abstract

Coordination and biocidal aspects of lanthanide(III) complexes with 3-formyl-4-chlorocoumarin hydrazinecarbothioamide (L¹H) and 3-formyl-4-chlorocoumarin hydrazinecarboxamide (L²H) are described with the support of elemental analyses, molecular weight, melting point, and molar conductance determinations along with the IR, ¹H NMR, EPR, UV spectral, and X-ray powder diffraction studies. The spectral data suggest that the ligands are monobasic bidentate, coordinating through nitrogen and sulfur/oxygen. The isolated products are colored solids, soluble in DMSO, DMF, and methanol. All the complexes are monomeric, as indicated by their molecular weight determinations. Conductivity measurements in dry DMF show them to be non-electrolytes. The antimicrobial, DNA cleavage, pesticidal, and nematicidal activities were examined and are discussed.

Keywords:

• 3-Formyl-4-chlorocoumarin hydrazinecarbothioamide
• 3-Formyl-4-chlorocoumarin hydrazinecarboxamide
• DNA cleavage activity
• Pesticidal and nematicidal activities

Acknowledgments

The authors are thankful to UGC, New Delhi, India for financial assistance through grant no. 34-324/08/(SR-I) and CSIR, New Delhi through grant no. 01(2307)/09/EMR-II.