Effect of Rate and Quantum Yield of 1-alkyl-2-(arylazo) Imidazoles on the Surface of Silver Nps

Abstract

1-Alkyl-2-(arylazo)imidazole(RaaiR/) exists in trans-structure about –N=N- bond at ambient condition. Upon optical excitation in UV region the trans-RaaiR/ isomerises to cis-RaaiR/. The photochromism is very susceptible to internal substituents and external environment like solvent polarity, viscosity and presence of innocent foreign molecule. The changes from cis-to-trans occurs slowly in visible light excitation it has significantly faster rate at higher temperature. In this work we have studied the effect of silver nanoparticle on the photochromic activity of RaaiR/. The quantum yield of the photoisomerisation is dropped by 9-27% in inclusion phase AgNPs@RaaiR/ than free state and the order of rate is: free state > silver nano particle. The activation energy (Ea) of cis to trans isomerisation is also diminished compared to free state of photochrome.