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 pi conjugation or 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. (C) 2003 Elsevier Science Ltd. All rights reserved.