Counterion-Mediated Crossing of the Cyanine Limit in Crystals and Fluid Solution: Bond Length Alternation and Spectral Broadening Unveiled by Quantum Chemistry

Absorption spectra of cyanine⊕·Br⊖ salts show a remarkable solvent dependence in non/polar solvents, exhibiting narrow, sharp band shapes in dichloromethane but broad features in toluene; this chan...