Synthesis, characterization, thermal and biological activity of some novel Cadmium(II) – pyridine and purine base complexes

Article type: Research Article

Authors: Gandhi, Namita^a | Kumar, Amit^{b; e} | Kumar, Chaitnaya^e | Mishra, Neeraj^e | Chaudhary, Pratibha^c | Kaushik, N.K.^d | Singh, Rajeev^{e; *}

Affiliations: [a] Department of Chemistry, Deshbandhu College, University of Delhi, Kalkaji, New Delhi, India | [b] School of Material Chemistry, Japan Advanced Institute of Science and Technology (JAIST), 1-1 Asahidai, Nomi city, Ishikawa, Japan | [c] Department of Chemistry, Maitreyi College, University of Delhi, Chanakyapuri, New Delhi, India | [d] Department of Chemistry, University of Delhi, Delhi, India | [e] Material/Organometallics Laboratory, Department of Chemistry, Atma Ram Sanatan Dharma College, University of Delhi, Dhaula Kuan, New Delhi, India

Correspondence: [*] Corresponding author: Rajeev Singh, Material/Organometallics Laboratory, Department of Chemistry, Atma Ram Sanatan Dharma College, University of Delhi, Dhaula Kuan, New Delhi-110007, India. Tel.: (+91) 9311 2255 01; Fax: (+91) (11) 24111390; E-mail: rajeev@arsd.du.ac.in

Abstract: A new series of cadmium(II) complexes with biological active ligands such as niacinamide (L1), isoniazid (L2), purine bases: theophylline (HL3) and theobromine (L4), isoniazid derivatives: isoniazid dithiocarbazate (HL5), S-methyl ester of Isoniazid dithiocarbazate (L6) and S-ethyl ester of Isoniazid dithiocarbazate (L7), of the type Cd(L)2I2 or Cd(L)I2 or Cd(L)2 have been synthesized in anhydrous THF. The complexes were characterized by elemental analysis, conductance measurement, UV-vis, IR, 1H-NMR, and mass spectral studies. Various kinetic and thermodynamic parameters of these complexes have also been determined using TG/DTA technique. The thermal decomposition techniques indicate the formation of CdS2 as a residue. The results show that the L1, L3 and L4 act as unidentate while rest of the ligands act as bidentate, forming a five-member chelate ring with L2, four member chelate ring with L5, L6, L7 and no chelation in L1, L3 and L4. The complexes are 1:1 or 1:2 metal-ligand complexes. In order to assess their antimicrobial activity, the ligands and their corresponding complexes have also been tested in vitro against bacteria (E.coli, P.aeruginosa, S.aureus and K.pneuonia) and fungi (Rhizopus oryza and Aspergillus flavus). All the complexes exhibit remarkable activity and the results provide evidence that the studied complexes might indeed be a potential source of antimicrobial agents.

Keywords: Cadmium, pyridine bases, purine bases, antimicrobial, complex

DOI: 10.3233/MGC-150181

Journal: Main Group Chemistry, vol. 15, no. 1, pp. 35-46, 2016