Solvent effect on static and dynamic first hyperpolarizability of azochromophore with tricyanopyrrole acceptor moiety

• Published in: Journal of molecular liquids 2021-05, Vol.330, p.115665, Article 115665
• Main Authors: Shalin, Nikita I., Phrolycheva, Yulia A., Fominykh, Olga D., Balakina, Marina Yu
• Format: Article
• Language: English
• Subjects: Chromophores; First hyperpolarizability; Hydrogen bonding; Polarizable continuum model; Semicontinuum approach; Solvent effect; Supermolecule
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2021.115665

Solvent effect on molecular nonlinear optical (NLO) characteristics of azochromophore with tricyanopyrrole acceptor, AAB-TCP, is estimated within different models: polarizable continuum model (PCM), supermolecule (SM), semicontinuum (SC). The values of first hyperpolarizability are calculated by TD-DFT at M06-2X/aug-cc-pVDZ level; the dynamic characteristics are evaluated at 0.65 eV frequency. Molecular dynamics of AAB-TCP solution in acetone (at concentration 2·10−2 mol%) is performed in amorphous cell what allowed to reveal different types of hydrogen-bonded supermolecules formed by AAB-TCP and one or two acetone molecules; for four supermolecules the first hyperpolarizability values are calculated. Solvent effect accounted within the PCM approach causes almost 4 times increase of static first hyperpolarizability. The account of direct interaction within supermolecule model results in the growth of first hyperpolarizability and describes the solvent effect partly; the estimations at semicontinuum level show further increase (by 40% for static and 50% for dynamic cases) of first hyperpolarizability compared to the PCM values, thus demonstrating the role of solute-solvent hydrogen bonding. [Display omitted] •Solvent effect on first hyperpolarizability of AAB-TCP chromophore is studied within different models.•Molecular dynamics of AAB-TCP solution in acetone allowed revealing different types of hydrogen-bonded supermolecules.•Solvent effect accounted within the PCM approach causes almost 4 times increase of static first hyperpolarizability.•The account of direct solute-solvent interaction is shown to be important in describing solvent effect.•The estimations at semicontinuum level show increase of first hyperpolarizability compared to the PCM.