Synthesis and solid-state structure of the unsymmetrical squaraine dye 2-[4-(dibutylamino)-2-hydroxyphenyl]-4-[4-(dibutylamino)phenyl]- cyclobutenebis(ylium)-1,3-diolate

Article abstract of DOI:10.1071/CH9961339

The synthesis of an unsymmetrical squaraine dye, 2-[4-(dibutylamino)-2-hydroxyphenyl]-4-[4-(dibutylamino)phenyl] cyclobutenebis(ylium)-1,3-diolate, has been achieved via a cross condensation reaction. In the solid state the compound is isomorphous with the known symmetrical dye bis[4-(dibutylamino)phenyl]squaraine. The single hydroxy group is found to be disordered equally over the centrosymmetrically trans-related ortho and ortho' phenyl ring sites.