Synthesis, structural characterization, in-vitro antibiogram assay and efficient catalytic activities of transition metal(II) chelates incorporating (E)-(2-((2-hydroxybenzylidene)amino)phenyl)(phenyl)methanone ligand Vellaichamy Muniyandi a , Narayanaperumal Pravin a , Liviu Mitu b , Natarajan Raman a,⇑ a Research Department of Chemistry, VHNSN College, Virudhunagar 626 001, Tamil Nadu, India b Department of Chemistry, University of Pitesti, Pitesti 110 040, Romania highlights  Synthesis of new DNA targeting metal chelates.  Square planar geometrical arrangements of the complexes.  The newly synthesized metal chelates act as persistent intercalators.  Metal chelates display better chemical nuclease activity.  They exhibit excellent catalytic performance towards the oxidation of toluene. graphical abstract article info Article history: Received 3 December 2014 Received in revised form 6 January 2015 Accepted 6 January 2015 Available online 13 January 2015 Keywords: Square planar Intercalation Biological activity DNA cleavage Catalytic activity abstract A new tridentate ligand, (E)-(2-((2-hydroxybenzylidene)amino)phenyl)(phenyl)methanone and its four metal(II) chelates have been designed and synthesized. They were structurally characterized by elemen- tal analysis, FT IR, UV–vis, 1 H NMR, 13 C NMR, mass spectra, EPR, magnetic moment and conductivity mea- surements. Elemental analysis and molar conductance values reveal that all the chelates are 1:1 stoichiometry of the type [MLCl] having non-electrolytic nature. The metal chelates adopt square planar geometrical arrangements around the metal ions. The DNA-binding properties of these chelates have been investigated by electronic absorption, cyclic voltammetry, differential pulse voltammogram and vis- cosity measurements. The data indicate that these complexes bind to DNA via an intercalation mode. The oxidative cleavage of the metal complexes with pBR322 DNA has also been investigated by gel electro- phoresis. Moreover, the antimicrobial bustle shows that all metal chelates have superior activity than the free ligand. The oxidation of toluene to benzaldehyde is effectively catalyzed by the synthesized chelates. Ó 2015 Elsevier B.V. All rights reserved. Introduction For the past few decades, transition metal complexes have been paid much attention in the study of mutation of genes in therapeu- tic approaches [1,2]. In chemotherapeutic approach DNA will be the http://dx.doi.org/10.1016/j.molstruc.2015.01.011 0022-2860/Ó 2015 Elsevier B.V. All rights reserved. ⇑ Corresponding author. Tel.: +91 092451 65958; fax: +91 4562 281338. E-mail address: ramchem1964@gmail.com (N. Raman). Journal of Molecular Structure 1086 (2015) 56–63 Contents lists available at ScienceDirect Journal of Molecular Structure journal homepage: www.elsevier.com/locate/molstruc