Design And Synthesis Of 3H-Naphtho[2, 1-b]Pyrans Compounds & Studies On Their Photochromic Characteristics

Photochromism is a distinct and technologically important process where a molecular is induced by light to rearrange into a new form which has a different absorption from that its precursor. Since organic photochromism have extensive potential use both in daily life and high technique field. Studies on organic photochromism have significance either in practical application or in theoretical aspect.Naphthopyran is one of the most promising candidates due to their outstanding properties such as high photocolourability and remarkable fatigue resistance. Despite of their many important applications, the more particularly advantageous known applications is ophthalmic lens for the purpose of screening light radiation as a function of its intensity. In this dissertation the research of organic photochromic materials and the development of naphthopyrans are reviewed. In this paper, three series of new substituted 3H-naphthopyrans have been chosen as target molecules. Detailed studies on their photochromic properties were made out and the relation between molecular structure and properties were studies.The photochromism results indicate that all these materials exhibit good photochromic properties in both solid states and solution. Furthermore they possess excellent solubility and film formation property. And they have good fatigue resistance in doped in PMMA. The POM and DSC indicate that 8-dodecyl-3H-naphthopyrans manifest the nematic liquid-crystalline property affirmed from their textures.Furthermore, microwave technique had first adopted to improve the synthesis of the spirooxazins compounds, and got two kinds of spirooxazins compounds with better yields. The two spirooxzaines have been applied in optical store studies. Studies on fluorescence of two spirooxazines' open form in CHCl₃ and manifest that 6'-piperidine-spirooxazine is more stable than 6-cyano-spirooxazine.