Optical properties of guest host systems based on cellulose derivatives

Guest host systems composed of various types of esters of (2-hydroxypropyl) cellulose and the chromophore coumarin 334 were characterized with respect to the absorption and emission properties as a function of the concentration of the chromophore and the nature of the esters. The results were compared with the ones obtained for solutions of the chromophore with low molar mass solvents. The cellulose derivatives are characterized by good film forming capabilities, a high solubility for the chromophores, by significant solvatochromic effects both in absorption and emission and by the formation of excimers at elevated concentration of the chromophores. These features make such cellulose derivatives interesting candidates as matrix materials for host-guest systems in areas such as organic light emitting devices or sensors. Their tendency to display a cholesteric superstructure is of particular interest.