Synthesis and molecular structure of a zinc complex of the vitamin K3 analogue phthiocol

Kathawate, L., Sproules, S. , Pawar, O., Markad, G., Haram, S., Puranik, V. and Salunke-Gawali, S. (2013) Synthesis and molecular structure of a zinc complex of the vitamin K3 analogue phthiocol. Journal of Molecular Structure: THEOCHEM, 1048, pp. 223-229. (doi: 10.1016/j.molstruc.2013.05.057)

Abstract

The complex [Zn(phthiocol)2(H2O)2]; 1, where phthiocol is 2-hydroxy-3-methyl-1,4-naphthoquinone, has been synthesized and characterized by elemental analysis, FT-IR, 1H NMR, UV–vis spectroscopy, thermogravimetric (TG) analysis, electrochemical and single crystal X-ray diffraction studies. The νCO stretch shifts to lower frequencies upon complexation of phthiocol to Zn2+. 1H NMR spectra show an upfield shift of the benzenoid ring protons in 1. There is a bathochromic shift of the LMCT band in the UV–vis spectra of 1. Single crystal X-ray structure of 1 show distorted octahedral geometry around Zn2+. Two phthiocol ligands are in plane with the metal, while water molecules are trans to this plane. Coordination of deprotonated phthiocol ligands is ‘trans, trans’ to Zn2+. Intra as well as intermolecular interactions are observed in 1. Molecules of 1 show three dimensional network through CH⋯O and OH⋯O interactions. Additional anodic peaks are observed in cyclic voltammogram of phthiocol ligand due to oxidation of reduced species formed during reduction. One-electron reduction of 1 is shown to be reversible and DFT studies define this redox event as ligand-centered.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Sproules, Dr Stephen
• Authors: Kathawate, L., Sproules, S., Pawar, O., Markad, G., Haram, S., Puranik, V., and Salunke-Gawali, S.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Journal of Molecular Structure: THEOCHEM
• Publisher: Elsevier B.V.
• ISSN: 0166-1280
• ISSN (Online): 2210-2728