Synthesis and properties of fluorescent 1,8-naphthalimide dyes for application in liquid crystal displays

A series of highly fluorescent 1,8-naphthalimide derivatives having an N-allylamino group at position 4 of the aromatic structure have been synthesised, and some of their properties for application in liquid crystal displays have been determined. The optical properties of the new substances are studied both in organic solvents and in the nematic liquid crystal ZLI 1840. The utility of the dyes for colouring liquid crystal displays of the "guest-host" type is discussed on the basis of their spectral properties (absorption and emission) and the effect that the dyes have upon the orientation order parameter [P-2] and upon the phase-transition behaviour of the liquid crystal in surface-stabilised display cells.