A computationally-derived model for the solvatochromism of -phenolates with high predictive power

• Published in: Physical chemistry chemical physics : PCCP 2018-07, Vol.2 (26), p.18127-18132
• Main Authors: Mera-Adasme, Raúl, Domínguez, Moisés
• Format: Article
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c8cp02424c

We report that the positive, reverse or negative solvatochromism of p -phenolate-based dyes is highly correlated with the multireferential (MR) character of their ground-state wave function, with negative compounds presenting the highest degeneracy. CASSCF/NEVPT2 calculations show that the high MR character of the wave-function in negative dyes allows those systems to increase the dipole moment of the ground state by breaking the degeneracy as a response to the field of a polar solvent. The resulting stabilization of the ground-state with increasing solvent polarity leads to the observed negative solvatochromic behavior. A computational indicator based on our results has been successfully used for determining the direction of the solvatochromic shift of 24 dyes. Thus, our work sheds light on the physical-chemical basis for solvatochromism while providing experimental chemists with a practical tool for the design of novel negative, positive or reverse solvatochromic dyes. We report that the positive, reverse or negative solvatochromism of p -phenolate-based dyes is highly correlated with the multireferential (MR) character of their ground-state wave function, with negative compounds presenting the highest degeneracy.