13 ноември 2025
Neacsu, A., Minkovska, S., Alexiev, V., Chihaia, V..
(
Валентин Алексиев;
Стела Минковска-Додова;
)
Abstract
This work focuses on the investigation of ten newly synthesized spironaphthoxazines using DFT to elucidate how substituents control physicochemical behavior. Frontier-orbital analyses show substituent changes primarily shift the LUMO, controlling HOMO–LUMO gaps and electrophilicity; the open forms (MC) structures exhibit smaller gaps than closed spiro forms (SP) due to extended conjugation. Simulated IR/Raman spectra provide diagnostic markers for structural assignment. Thermodynamic parameters (S, Cp, H, G; 200–500 K) reveal higher S and Cp for MC and for longer alkyl chains, yielding lower G at elevated temperatures. Transition-state calculations indicate accessible SP?MC isomerization barriers, confirming accessible switching. These results offer a predictive framework to position functional groups and tailor optical response, switching kinetics, and stability for responsive materials.
Chemistry Proceedings, 18, 1, MDPI, 2025, ISSN:2673-4583, DOI:10.3390/ecsoc-29-26899, 67 Международно академично издателство (EBSCO)
https://www.mdpi.com/2673-4583/18/1/67
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