Polymorphism of Merocyanine Dyes Homologues with 1,3-Diethyl-2-thiobarbituric Acid Acceptor and p-Dimethylaminobenzene Donor and Different Polymethine Chains Connecting Them

The crystallization from different solvents of homologues of 1,3-diethyl-2-thiobarbituric acid and p-dimethylaminobenzene with different lengths of the polymethine bridge between donor and acceptor groups (TB[n]) produced three pairs of polymorphs with the number of C=C bonds in the chain n = 1, 3, and 5. The homologues with the shortest (one methine unit) π-conjugated bridge were presented by two concomitant (obtained simultaneously) polymorphs. Bond length alternation values calculated using X-ray data and evaluation using NMR data showed that some homologues possesses a very high hyperpolarizability. It was shown that the increase of polarizability is related to the increase in the length of the π-conjugated bridge that was supported by experimental hyper-Rayleigh scattering data. Density functional theory calculations of HOMO/LUMO molecular energy levels indicated that compounds with a longer π-conjugated bridge have a higher thermal stability. © 2019 American Chemical Society.

Авторы
Rigin S.1 , Tillotson J.2 , Perry J.2 , Khrustalev V.N. 1, 3 , Bogdanov G.1 , Timofeeva T.V. 1
Редакторы
-
Издательство
American Chemical Society
Номер выпуска
1
Язык
Английский
Страницы
167-177
Статус
Опубликовано
Подразделение
-
Номер
-
Том
20
Год
2020
Организации
  • 1 Department of Chemistry, New Mexico Highlands University, Las Vegas, NM 87701, United States
  • 2 School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, GA 30332, United States
  • 3 Peoples' Friendship University of Russia (RUDN University), Moscow, 117198, Russian Federation
Ключевые слова
Bond length; Polymorphism; X ray scattering; Bond length alternation; Conjugated bridges; Different solvents; Donor and acceptor; Hyper Rayleigh scattering; Hyper-polarizability; Molecular energy levels; Polarizabilities; Density functional theory
Дата создания
10.02.2020
Дата изменения
10.02.2020
Постоянная ссылка
https://repository.rudn.ru/ru/records/article/record/56539/