Synthesis, Structure, and Properties of Supramolecular Charge-Transfer Complexes between Bis(18-crown-6)stilbene and Ammonioalkyl Derivatives of 4,4′-Bipyridine and 2,7-Diazapyrene

Abstract

4,4'-Bipyridine and 2,7-diazapyrene derivatives (A) having two ammonioalkyl N-substituents were synthesized. The complex formation of these compounds with bis(18-crown-6)stilbene (D) was studied by spectrophotometry, cyclic voltammetry, (1)H NMR spectroscopy, and X-ray diffraction analysis. In MeCN, π-donor D and π-acceptors A form supramolecular 1:1 (D·A) and 2:1 (D·A·D) charge-transfer complexes. The D·A complexes have a pseudocyclic structure as a result of ditopic binding of the ammonium groups to the crown-ether fragments. The better the geometric matching between the components, the higher the stability of the D·A complexes (log K up to 9.39). A key driving force of the D·A·D complex formation is the excessive steric strain in the precursor D·A complexes. The pseudocyclic D·A complexes involving the ammoniopropyl derivative of 4,4'-bipyridine were obtained as single crystals. Crystallization of the related ammonioethyl derivative was accompanied by transition of the D·A complexes to a structure of the (D·A)(m) coordination polymer type.

Complexation of bis‐crown stilbene with alkali and alkaline‐earth metal cations. Ultrafast excited state dynamics of the stilbene‐viologen analogue charge transfer complex

“…Alkali and alkaline‐earth metal perchlorates can not only react with free macrocyclic moieties of compound 1 but also displace the coordinated ammonium ions from them in complexes of type 1 · 2 . Indeed, upon the addition of Li, Na, K, Mg, Ca, and Ba perchlorates, the absorption spectra of 1 · 2 in acetonitrile show a minor long‐wavelength shift accompanied by intensity increase and appearance of a clear isosbestic point (Figure ).…”

“…High thermodynamic stability of these complexes (log K s 1:1 of up to 9.42 in MeCN) is due to the coordination of the ammonioalkyl groups to the crown ether moieties of stilbene 1 (see Chart 1). The “structure‐property” relationship has been studied for related donor‐acceptor complexes, differing in the length of the ammonioalkyl spacers and the type of the central conjugated moiety in the acceptor component . It was shown that these complexes can be regarded as fluorescent molecular sensors for alkaline‐earth metal cations.…”

Effect of Interchromophoric Stacking Interactions on the Stability of the Sandwich-Type Complexes of 1-Hydroxy-9,10-anthraquinone-9-iminobenzo-15-crown-5 ether with Metal Cations

“…Краун-эфиры и их производные широко при-меняются не только в качестве селективных лигандов для катионов металлов, но и как рецепторные модули в дизайне различных супрамолекулярных систем, [1][2][3] например, оптических молекулярных сенсоров (ОМС). [4] Одним из известных свойств краун-эфиров, которое используется в супрамолекулярном дизайне, является способность образовывать сэндвичевые комплексы с от-носительно большими катионами металлов.…”

Novel Linear Bis-Crown Receptors with Cross-Conjugated and Conjugated Central Cores

“…[29] PCA itself and its stereoselectivity can be controlled by supramolecular preorganization of double bonds, to create the most suitable geometry of the starting dimer. [30][31][32][33][34] We have previously shown that bis-crown stilbenes can form unusual bi-and exotic trimolecular complexes in the reaction with diammonioalkyl derivatives of viologen or cyanine dyes, [35][36] due to the formation of a system of hydrogen bonds. Owing to the spatial preorganization of the donor and acceptor regions of supermolecules, an effective intermolecular charge transfer has been observed in the complexes produced.…”