Ultrafast excited state dynamics, direct and back [2 + 2]-cross-photocycloaddition of a styryl dye–stilbene charge transfer complex. (February 2021)

• Record Type: Journal Article
• Authors: Volchkov, Valery V.; Martyanov, Timofey P.; Khimich, Mikhail N.; Rusalov, Mikhail V.; Neznaeva, Daria A.; Gostev, Fedor E.; Shelaev, Ivan V.; Nadtochenko, Victor A.; Melnikov, Mikhail Ya; Moiseeva, Anna A.; Ushakov, Evgeny N.; Gromov, Sergey P.
• Is Part Of: Dyes and pigments. Volume 185(2021)Part B
• Publication Date: 2021-02
• Subjects: Styryl dyes -- E–Z photoisomerization -- [2 + 2] photocycloaddition -- Cyclobutanes -- Bis-crown ethers -- Intrasupramolecular photo-driven electron transfer; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2020.108952
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: This research is dedicated to the study of bis(ammoniopropyl) derivative of ( E )-4-(4-mercaptostyryl)pyridine dye (2 ), forming a highly stable bimolecular complex with a bis(18-crown-6 ether) derivative of ( E )-stilbene (1 ) in solution owing to ditopic coordination via hydrogen bonds. The spectral-kinetic parameters of E isomer of the dye and its complex were obtained using steady-state absorption, fluorescence, and time-resolved absorption spectroscopy. The stability constant of the complex, quantum yields of cross-PCA and retro-PCA reactions were determined by spectrophotometric titration methods. According to density functional theory calculations, E–Z photoisomerization of dye 2 occurs via non-radiative deactivation from intermediate twisted (TICT) state. The detailed study of stereospecific [2 + 2]-cross-photocycloaddition (cross-PCA) of complex ( E )-1 ·( E )-2 and back reaction of cross-PCA product ( rctt -3 ) was carried out. The complexation reaction of cyclobutane rctt -3 with Ba 2+ ions has been investigated. A highly efficient direct intrasupramolecular photoelectron transfer and the back electron transfer of a moderate efficiency were found for the complex ( E )-1 ·( E )-2 . Graphical abstract: Image 1