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Complexation of bis‐crown stilbene with alkali and alkaline‐earth metal cations. Ultrafast excited state dynamics of the stilbene‐viologen analogue charge transfer complex
Author(s) -
Volchkov Valery V.,
Rusalov Mikhail V.,
Gostev Fedor E.,
Shelaev Ivan V.,
Nadtochenko Viktor A.,
Vedernikov Artem I.,
Efremova Asya A.,
Kuz'mina Lyudmila G.,
Gromov Sergey P.,
Alfimov Michael V.,
Ya. Melnikov Mikhail
Publication year - 2018
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.3759
Subject(s) - chemistry , excited state , flash photolysis , acetonitrile , photochemistry , ultrafast laser spectroscopy , alkali metal , absorption band , absorption spectroscopy , electron transfer , quenching (fluorescence) , fluorescence , spectroscopy , reaction rate constant , kinetics , organic chemistry , physics , quantum mechanics , nuclear physics , optics
The complex formation of bis(18‐crown‐6)stilbene ( 1 ) and its supramolecular donor‐acceptor complex with N , N ′‐bis(ammonioethyl) 1,2‐di(4‐pyridyl)ethylene derivative ( 2 ) with alkali and alkaline‐earth metal perchlorates has been studied using absorption, steady‐state fluorescence, and femtosecond transient absorption spectroscopy. The formation of 1 ∙M n + and 1 ∙(M n + ) 2 complexes in acetonitrile was demonstrated. The weak long‐wavelength charge‐transfer absorption band of 1 · 2 completely vanishes upon complexation with metal cations because of disruption of the pseudocyclic structure. The spectroscopic and luminescence parameters, stability constants, and 2‐stage dissociation constants were calculated. The initial stage of a recoordination process was found in the excited complexes 1 ∙M + and 1 ∙(M + ) 2 (M = Li, Na). The pronounced fluorescence quenching of 1 · 2 is explained by very fast back electron transfer ( τ et = 0.397 ps). The structure of complex 1 · 2 was studied by X‐ray diffraction; stacked ( 1 · 2 ) m polymer in which the components were connected by hydrogen bonding and stacking was found in the crystal. These compounds can be considered as novel optical molecular sensors for alkali and alkaline‐earth metal cations.