Investigation on Solvatochromic Effects on Molecular Dynamics, and Light Absorption and Emission of Novel Azospiropyran Photochromic Dyes

In photochromic structures based on spiropyrans، two rings of spiro moiety are perpendicular. Merocyanine form with linear and conjugated structure produces by exposure to UV irradiation. Physicochemical properties of the molecular changes owing to this isomerization، and molecule switches between colored and colorless forms. Since، chemical properties of medium is highly effective on photochromic properties and reversibility، in this study، stability and photoresponces of three azospiropyran based photochromic molecule in different organic media were studied. Also، maximum absorption and molar absorption coefficient of these photochromic dyes in different solvents were evaluated. Solvatochromic effects were studied in switching ON/OFF of the molecules. J. Color Sci. Tech. 9 (2015)، 259-271©. Institute for Color Science and Technology.