Synthesis And Spectroscopic Performance Of Spiropyran Having Different Functional Groups

Nowadays, as a type of novel functional material, photochromic material of spiropyran (SP) has been widely used. The SP structure can transform to open ring MC form when it is inspired by external stimulus along with reversible changeson its color, ultraviolet absorption, fluorescence emission, dipole moment, crystal structure, and electricity etc. Taking advantages from these special changes, SP was widely researched andapplied in molecular switch, ion/molecule detection, fluorescent imaging, optical wettability, data storage, logic operations, and smart mechanical materials etc.In order to get different kinds of spiropyrans, we designed and synthesized spiropyran compounds with different functional groups such as alkyl,hydroxy,carboxyl,ester etc. The synthesis process was improved and the product yield was increased. The molecular structures of the target products are determined by using infrared spectroscopy andnuclear magnetic resonance.We choose the spiropyran with a hydroxyl group to investigate its photochromic behavior under different conditions including illumination, temperature,pH value, solvent, and other factors by using UV-Visiblespectrophotometer. The results show that the photochromic process of the SP is significantly affected by these conditions. Through the analysis and researchonthedynamics ofthe photochromic process of the SP, we found that first-order kinetics coincides well with those from solvents having a medium polarity while in the cases of the solvents with strong or weak polarity it is quite complicated.In the preparationprocess of theorganic/inorganic hybridmaterials, organic ligand having a mercapto group is quite important when it is introduced ontothe surface of inorganic particles. Therefore we explore themethodhow to combine a mercapto group with spiropyran compound bydesigningdifferent experimentalscheme. The synthesized product is characterized by usinginfrared spectroscopy andnuclear magnetic resonance. Inthecurrentstudy, thespiropyran moleculescan be linked onto the surface of inorganicnanoparticles of quantum dots to achieve two-state modulation on fluorescence emission. We designedquantum dots with dualphotochromic groups that complete a multi-level modulation by controlling the light.