Synthesis and crystal structure of N-6-[(4-pyridylamino)carbonyl]-pyridine-2-carboxylic acid methyl ester zinc complex

Abstract

A reaction between monoamide ligand namely N-6-[(4-pyridylamino)carbonyl]-pyridine-2-carboxylic acid methyl ester (L4) and zinc chloride has been attempted in order to generate a carboxylate complex suitable for anion inclusion. This reaction gives rise to a formation of discrete complex with general formula [ZnCl₂(L4)₂]. Complex [ZnCl₂(L4)₂] crystallizes in the monoclinic space group, P21/c, with one zinc(II) center, one molecule of ligand L4, one coordinated chloride and one methanol molecule in the asymmetric unit. The extended structure of this molecule shows that the zinc atom is coordinated by four donors: two L4 and two chloride anions. The zinc atom adopts distorted tetrahedral geometry with the angles between the donors in the range 103.62(11)-122.74(8)°. In this study, the amide cavity is bound with methanol through hydrogen-bonding interactions. The methanol molecules is hydrogen bonded to the amide moiety with bond lengths O30-H8···O12 and N17-H17···O30 of 1.988 and 2.078 Å, respectively.

Keywords:

• Monoamide
• Methyl ester
• Zinc complex
• Anion binding
• Carboxylate

Acknowledgements

The authors greatly acknowledge the scientific support from Universiti Malaysia Terengganu and University of Adelaide. Ministry of Higher Education Malaysia is also acknowledged for financial support through Fundamental Research Grant Scheme (FRGS Vot 59293).