Nickel tetrazolato complexes synthesized by microwave irradiation: Catecholase like activity and interaction with biomolecules

Abstract

1,3-Dipolar cycloaddition between nickel-ligated azide in [NiL(N₃)] [HL = 3-(2-diethylamino-ethylimino)-1-phenyl-butan-1-one] and two different organonitriles furnished two new square-planar complexes viz. [NiL(5-phenyltetrazolato)] and [NiL{5-(4-pyridyl)-tetrazolato}]. Both the complexes have been characterized by spectroscopic tools and single-crystal X-ray crystallography. Interaction with different biomolecules revealed that both complexes bind strongly to serum albumin proteins and show moderate catecholase-like activity by catalyzing the oxidation of 3,5-ditertbutylcatechol (3,5-DTBC). Identification of intermediates formed in catechol oxidation has been explored by ESI-MS spectrometry.

Keywords:

• Nickel
• tetrazolato complexes
• protein binding
• catecholase activity

Acknowledgments

We are grateful for the financial support received from the Council of Scientific and Industrial Research, New Delhi vide project no. 01(2829)/15/EMR-II. We are also thankful to Sophisticated Instrument Center, IIT Indore for analytical help.