The synthesis and dichroic properties of the squarylium chromophores

Over the last few decades, liquid crystals have made a noticeable impact in the commercial world as a result of their application and development in new display technologies to interface with the increasing number of electro-optical devices. For example, the use of a dichrioc dye (the guest) dissolved in a liquid crystal (the host) to make electrode transmission mode display devices. As a result the dichroic dye is characterised as dye structure with maximum absorbance along their principal axis and minimum absorbance along their minor axis. Now such dyes are used in potable computer and video devices. Particular, some squarylium compounds based on donor-acceptor chromophores have a very intense, narrow absorption band and also have a long rod-like molecular structure. Our results show that squarylium dyes could be produced excellent dichroic properties and are of practical use for guest-host LCDs. Also, the squarylium compounds based on donor-acceptor chromophores were investigated and the visible absorption spectroscopic properties of the various squaryliums were examined. Our results show that squaryliums could be possible to be produced near-infrared absorbing materials with a view to investigate colour.