Synthesis and Solid-State Structure of the Unsymmetrical Squaraine Dye 2-[4-(Dibutylamino)-2-hydroxyphenyl]-4-[4-(dibutylamino)phenyl]-cyclobutenebis(ylium)-1,3-diolate

Abstract

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.