Effect of Cis/trans-Isomerisation on Photoalignment of Azo Dyes

Using potassium 5-[{4′-[(5′-carboxy-4′-hydroxy-2′-methylphenyl)diazenyl]biphenyl-4-yl}diazenyl]-2-hydroxy-4-methylbenzoate and potassium 3-[{4′-[(3-carboxy-2,4-dihydroxyphenyl)diazenyl]biphenyl-4-yl}-diazenyl]-2,6-dihydroxybenzoate as examples, cis/trans-isomerization of azo dyes in solutions and dynamics of their photoalignment in thin film under irradiation with polarized light were studied.