The geometries, absorption and fluorescence wavelengths of solvated fluorescent coumarins: A CIS and TD-DFT comparative study

CIS and TD-DFT excited-state structures in gas-phase and water have been determined for several hydroxy coumarin dyes. Though the CIS transition energies are strongly overestimated, this scheme reproduces the major chemical features. However, the solvatochromic effects are not consistently reproduced by CIS, especially for the emission properties.