ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Synthesis, structural and spectroscopic properties of asymmetric schiff bases derived from 2,3-diaminopyridine

Agnieszka Pazik, Beata Kamińska, Anna Skwierawska, and Łukasz Ponikiewski

Department of Chemistry and Technology of Functional Materials, Narutowicza Street 11/12, 80-233 Gdansk, Poland

E-mail: mikaga20@wp.pl

Abstract: Two Schiff base derivatives, 4-(2-amino-3-pyridyliminomethyl)phenol (I) and 3-(2-amino-3- pyridyliminomethyl)nitrobenzene (II ), were synthesised and characterised by spectroscopy. The structure of I was determined by single crystal X-ray diffraction studies. The asymmetric Schiff base derived from 2,3-diaminopyridine selectively recognise transition and heavy metal cations, and some anion. Ligands I and II form stable complexes with Cu²⁺, Zn²⁺, Pb²⁺, Al³⁺ whereas ligand I also binds F⁻ ions. The stoichiometry for the host : cation is 1 : 1 and 2 : 1. The addition of F⁻ ion in CH₃CN to ligand I causes a colour change of the solution from colourless to yellow. The binding behaviour of ligand I towards several ions was investigated using density functional theory calculations.

Keywords: asymmetric Schiff bases – X-ray crystal structure – cation complexation – fluoride – UVVISspectroscopy – 1H NMR spectroscopy

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2016-0058

Chemical Papers 70 (9) 1204–1217 (2016)