A ternary nickel(II) Schiff base complex containing di-anionic and neutral forms of a dithiocarbazate Schiff base

• Main Authors: Md Yusof, Enis Nadia, Muhammad Nasri, Nazhirah, Ravoof, Thahira B. S. A., Tiekink, Edward R. T.
• Format: Article
• Language: English
• Published: MDPI 2019
• Online Access: http://psasir.upm.edu.my/id/eprint/38386/1/38386.pdf; http://psasir.upm.edu.my/id/eprint/38386/; https://www.mdpi.com/1422-8599/2019/2/M1057

The title NiII complex, Ni(L)(LH2) (1), where LH2 is S-2-methybenzyl-β-N-(2-hydroxy-3-methoxybenzylmethylene) dithiocarbazate, was isolated from the reaction of Ni(acetate)2·4H2O and two molar equivalents of LH2. The complex was characterized by elemental analysis, spectroscopy (IR and UV) as well as by a single-crystal X-ray structure determination. The nickel(II) center is coordinated within a cis-NOS2 donor set that defines a square planar geometry. Three donor atoms, i.e., N, O, and S, are provided by a doubly deprotonated S-2-methybenzyl-β-N-(2-hydroxy-3-methoxybenzylmethylene) dithiocarbazate ligand while the fourth donor, i.e., a thione-S, comes from the neutral form of the dithiocarbazate ligand. In the LH2 ligand, an intramolecular hydroxy-O-H⋯N(imine) hydrogen bond is found. There is also an intra-ligand, charge assisted amine-N-H⋯O(phenoxide) hydrogen bond. A notable feature of the molecular packing is the formation of supramolecular chains sustained by π…π stacking interactions whereby the interacting rings are the five- and six-membered chelate and methoxybenzene rings. The chains are connected into a three-dimensional architecture by methyl-C-H⋯O(methoxy), methoxy-C-H⋯S(ester), and tolyl-C-H⋯π(tolyl) interactions.