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

Photochromic and molecular switching behaviour of Schiff base-containing pyrazolone ring

Pratima R. Surati and Bhavna A. Shah

Department of Chemistry, Veer Narmad South Gujarat University, Surat-395007, Gujarat, India

E-mail: bhavna606@gmail.com

Abstract: A new Schiff base compound, 4-[[(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)methylidene] amino]-1,5-dimethyl-2-phenyl-2,3-dihydro-1H-pyrazol-3-one (I ), was synthesised and characterised by elemental analysis and LC-MS, FTIR and 1H NMR spectra. The photochromic property of the synthesised compound investigated under 365 nm UV irradiation can be observed by solid state absorption and fluorescence spectra. The kinetic study showed that the photochromic reaction was of the pseudo-first-order. The photo-isomerisation was due to photo-induced intermolecular hydrogen bonding, which resulted in enol to keto transformation. The molecular switching behaviour was studied in solution with two inputs in three different systems (OH⁻ and Ag⁺), (OH⁻ and Cd²⁺) and (OH⁻ and Th⁴⁺) based on the UV absorption spectra. It exhibited the logic behaviour of XNOR, AND and NOR for Ag⁺, Cd²⁺ and Th⁴⁺ in alkaline media, respectively.

Keywords: Schiff base – photochromic – photo-isomerisation – molecular switch

Full paper is available at www.springerlink.com.

DOI: 10.1515/chempap-2015-0021

Chemical Papers 69 (2) 368–375 (2015)