The optimized structures were subjected to calculations of valence excitations with time-dependent DFT (TDDFT) in the ORCA-5.0.3 program package. Electronic properties were compared with regard to isomeric effects and solvent influence, for which the following models were constructed: gas phase (TP gas ), implicit solvation in acetonitrile (TP aceto impl ), implicit solvation in water (TP water impl ), and a combined exlicit-implicit aqueous solvation (TP water expl ). The latter model used the microsolvation cluster in each isomer. The implicit solvation in the isomers was modeled with the conductor-like polarizable continuum model (cpcm) approach. The TDDFT computations employed the same def2-TZVP basis set and ωB97X functional, 41 however with D4 dispersion correction instead of D2 in Gaussian-16 implementation. 10 singlet and 11 triplet excited states were accessed in the TDDFT protocol, while the discussion pre-dominantly follows the states under 5 eV. The TDDFT results were compared with those obtained from the complete active space self-consistent field (CASSCF) implementation with def2-TZVP basis set in OpenMolcas v. 23.06. The multiconfigurational approach relied on a (12, 10) active space with 12 electrons in 10 orbitals for each isomer in the gas phase. The selected orbitals in the active spaces for the ortho, meta, and para isomers are collected in Figure . State-averaging in the CASSCF calculations was performed separately over 6 singlet and 5 triplet states, respectively. The integrated RASSI framework in OpenMolcas was used to calculate energies and transition dipole moments of the valence excitations.