Synthesis And Properities Of Substituted 3H-naphtho[2,1-b]Pyrans

Recently, photochromic materials had been intensively studied by many researchers due to their potential applications in many new technologies and our daily life ,such as optical data recording ,nonlinear optics ,optical switching , optical computing , holographic systems and organic display materials .Among these materials , pyran compounds had been attracted wide attention for their outstanding properties, as they were sensitively responsive to light ,fade rapidly after irradiation and had high optical stability. All of these reasons made pyran compounds have promising practical application prospects. 3H-naphtho[2,1-b]pyrans was the best photochromic materials among pyran derivatives ,so most research work was focus on them .And almost all the work is refer to their photocolourability and fatigue resistance ,while their solubility in organic solvent is rarely reported ,which is an important properity in practical use. Based on the idea to promote the solubility of 3H-naphtha [2,1-b] pyrans, we designed and synthesized two 3H-naphtho[2,1-b]pyran compounds bonding a long alkyl chain in 8-position. By studying their photochromic properities ,we found 8-hexyl-3H-naphtho[2,1-b]pyran having advantageous photochromic properities,such as high colorability , rapid colouration kinetics in polymer medium and solution. And certaintly they had a better solubility in organic solvent than without a long soft alkyl chain.