Synthesis, structure and complexation of biscrown-containing 1,4-distyrylbenzenes

Pseudodimeric Complexes of an (18-Crown-6)stilbene with Styryl Dyes Containing an Ammonioalkyl Group: Synthesis, Structure, and Stereospecific [2 + 2] Cross-Photocycloaddition

“…18-Crown-6-containing stilbene ( E )- 1 was previously synthesized from the corresponding halogenated benzocrown ether and styrene in the presence of a palladium catalyst . Considering reported data for distyrylbenzenes, we proposed using the Horner–Wadsworth–Emmons reaction for the synthesis of ( E )- 1 . In the first step, condensation of benzyl bromide with triethyl phosphite was carried out by a known procedure, which gave diethyl benzylphosphonate 4 in 98% yield (Scheme ).…”

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

“…By using the quantum chemical calculations, we confirmed the more advantageous syn, (syn/anti), syn-conformation of the conjugated moiety of 1,4-distyrylbenzenes with four alkoxy substituents. [70] The obtained electrochemical oxidation and reduction potentials of bis-crown 1,4-distyrylbenzenes 3i,j and the model compound 3f in the solution are different from bis-crown-containing stilbenes. It has been established that the presence of an extended conjugation system leads to a significant facilitation of electrochemical reduction of distyrylbenzenes as compared to stilbenes.…”

“…We have developed our own method, based on the use of DMF as a solvent [70] (Scheme 2). The advantage of using DMF is that it easily dissolves starting compounds, whereas target 1,4-distyrylbenzenes are slightly soluble, so their isolation is greatly facilitated, especially when water is added into the reaction mixture after the reaction is completed.…”

“…It has been established that the presence of an extended conjugation system leads to a significant facilitation of electrochemical reduction of distyrylbenzenes as compared to stilbenes. [70] We studied the complex formation properties of biscrown distyrylbenzenes 3i and 3j. The stability constants of their complexes with alkali and alkaline earth metal perchlorates were determined by spectrophotometric and fluorescence titration.…”

“…For bis-styryl molecules, in addition to conformational features, it is possible to control this distance using a different method of connecting the central benzene ring with peripheral styryl moieties, namely, using para or meta substitution (see Figure 17). Figure 18 shows data on the distances between distant carbon atoms of benzocrown ether moieties obtained from X-ray diffraction experiments of cross-conjugated dienone 1g (two crystallographically independent molecules [51] ) and the model compound 3f (two crystallographically independent molecules [70] ). The data in Figure 18 clearly show that, for any dienone, the distance between the peripheral moieties is smaller than for 1,4-bis-styrylbenzene.…”