Abstract:
There are several classes of molecules in organic chemistry that exhibit photochromism, one of which is dithienylenthenes (DTEs). Photochromism is defined as a light-induced reversible transformation between two isomeric compounds. Upon irradiation with ultraviolet light, DTEs undergo a change in colour from colourless open-ring isomers to blue colored closed-ring isomers. This colour change is due to the extensive change in molecular geometry between their isomeric forms. The new DTE compounds that I have synthesized will be used to develop drug delivery vehicles that will release their drug cargo upon irradiation with light. Our DTEs will act as the ON/OFF switch for this delivery. These vehicles are prepared by incorporating our DTEs into the membrane of biocompatible lipid vesicles or liposomes, which are spherical, self-closed structures, composed of curved lipid bilayers which entrap part of the solvent, in which they freely float, into their interior. I have developed a new approach for the synthesis of symmetrical and asymmetrical DTE compounds. I will discuss these results and the recent synthesis of dimeric DTE molecules that will also be used in light-activated drug delivery therapies.