FULL PAPER Synthesis, spectral characterization, DFT studies and biological activity of novel Ligand 1‐(2‐cyclohexyl thioethyl) piperidine and its complexes with group 12 metal chlorides Muzzaffar A. Bhat 1,2 | Shabir H. Lone 3 | Muzzaffar A. Mir 2 | Sheikh A. Majid 2 | Sanjay K. Srivastava 1 1 School of Studies in Chemistry, Jiwaji University, Gwalior 474011, India 2 Department of Chemistry, Islamic University of Science and Technology, Awantipora, Kashmir 192122, India 3 Department of Chemistry, Govt Degree College Anantnag, Kashmir 192101, India Correspondence Muzzaffar Ahmad Bhat, Assistant Professor, Department of Chemistry, IUST Awantipora Kashmir, 192122. Email: muzzaffarbhat9@gmail.com Sanjay Kumar Srivastava, Professor, School of Studies in Chemistry, Jiwaji University, Gwalior, India, 474011. Email: sksrivas7@yahoo.com C 6 H 11 S ‐ Na + (generated insitu by reaction of NaOH with C 6 H 11 SH) on treat- ment with 1‐(2‐chloroethyl) piperidine hydrochloride under N 2 atmosphere resulted in (1‐(2‐cyclohexyl thioethyl) piperidine) (L 1 ) as orange solid. It's com- plexes having the formula [ZnCl 2 .L 1 ](1), [CdCl 2 . (L 1 )] (2) and [HgCl 2 .L 1 ](3) have been prepared. L 1 and its complexes 1‐3 were characterized on the basis of physico‐chemical and spectral (FT‐IR, Mass, 1 H, 13 C and DEPT 135 o NMR) studies. Powder XRD diffraction pattern reveals the crystalline nature of L 1 and complex 1. Complexes 1‐3 adopt distorted tetrahedral geometry showing bidentate mode of coordination through S and N. Using DFT‐based optimiza- tion of structures, the HOMO‐LUMO energy gaps and molecular electrostatic potential maps (EPM) of compound L 1 and complexes 1‐3 were theoretically calculated at the B3LYP/6‐311G (d, p) level of theory. HOMO‐LUMO energy gap was calculated which allowed the calculation of relative properties like chemical hardness, chemical inertness, chemical potential, nucleophilicity and electrophillicity index of the synthesized products. The experimentally obtained IR and NMR results showed a good correlation with those of the the- oretical ones. Ligand L 1 and complexes 1‐3 display significant antibacterial and antifungal activity. KEYWORDS Antibacterial, antifungal, bidentate, density functional theory, piperidine 1 | INTRODUCTION The morpholine and piperidine skeleton containing species are important in the synthesis of organic compounds [1] including pharmaceuticals [2] having selective enzyme inhibition. Antioxidant and hypocholesterolemic activities of 2‐biphenylmorpholine derivatives [3] have also been reported. The complexes of morpholine and its derivatives with Ni (II), [4] Cu (II), [5] Zn (II), [6] Cd (II), [6] Hg (II), [7] Os (II), [8] Re (III) [9] and Ag (I) [10] have been reported. Platinum (II)‐N‐(2‐aminoethyl)morpholine complexes have exhibited antitumor activities. [11] Ruthenium‐carbonyl‐piperidine complexes catalyze the oxidation of cinnamaldehyde and show antibacterial and antifungal activity. [12] 99m Tc‐nitrido dithioformate complexes containing piperidine rings can act as brain imaging agents. [13] Various aspects of allyl amination of Pd (II) allyl complexes containing chelating chalcogenated pyridine derivatives have been studied. [14] Received: 29 November 2017 Revised: 22 January 2018 Accepted: 23 January 2018 DOI: 10.1002/aoc.4329 Appl Organometal Chem. 2018;e4329. https://doi.org/10.1002/aoc.4329 Copyright © 2018 John Wiley & Sons, Ltd. wileyonlinelibrary.com/journal/aoc 1 of 13