Rational design and synthesis of a novel class of highly fluorescent rhodamine dyes that have strong absorption at long wavelengths

A novel class of strongly fluorescent rhodamine dyes were designed and synthesized by extending the π conjugation of chromophore with limited flexibility. These dyes were shown to have longer absorption in the range of 581 to 631 nm with quantum yields between 0.64 and 0.89. [Copyright &y& Elsevier]