Synthesis, structure, electrochemistry, and photophysics of 2,5-dibenzylidenecyclopentanones containing in benzene rings substituents different in polarity

Corrosion study of copper in aqueous sulfuric acid solution in the presence of (2E,5E)-2,5-dibenzylidenecyclopentanone and (2E,5E)-bis[(4-dimethylamino)benzylidene]cyclopentanone: Experimental and theoretical study

“…The compounds (2E,5E)-2,5-dibenzylidenecyclopentanone (M1) and (2E,5E)-bis[(4-dimethylamino)benzylidene]cyclopentanone (M2) were freshly prepared via the Claisen-S chmidt reaction between the cyclopentanone and corresponding aryl aldehyde in 82 and 64% yields, respectively. They are known compounds (dienones) with E, E stereochemistry and their spectroscopic data match those reported in the literature [22,25].…”

“…An additional useful feature is that M2 is fluorescent [14][15][16] as a free amine and the fluorescence is quenched under acidic conditions (i.e., upon protonation of the dimethylamino group). These 2,5-diarylidenecyclopentanones are known compounds and their structure and properties have been thoroughly investigated (Scheme 1) [22][23][24][25][26].…”

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

“…Papers examining individual compounds of this group are published. [45][46][47][48][49][50] Our paper [51] presents results from the physical and chemical studies of dienones 1a-g that are different in nature and have a number of substituents. It studies the structure (by X-ray diffraction and NMR spectroscopy), luminescence and photochemical properties, as well as the electrochemical properties, of the derivatives of crossconjugated dienones as model compounds of bis-azacrown analogues.…”

“…Among other things, we showed that there was a linear relationship between the electrochemical and spectrophotometric characteristics of dienone molecules. [56][57] To determine the relationship between the obtained light absorption data and the electrochemical data, and the dependence of such results on the electronic properties of the substituents in the benzene rings of dienones 1a-g, a correlation analysis of the following dependences was conducted: [51] (1) between the oxidation/reduction potential difference and the LWAB maximum energy, (2) the difference between the calculated HOMO/LUMO energies and the LWAB maximum energy, (3) between HOMO energy and the value of oxidation potentials, (4) between LUMO energy and the value of reduction potentials, (5) between para-σ-constants of substituents and the LWAB maximum energy. The most acceptable results were obtained for dependencies (1) (Figure 12) (with a correlation coefficient of 0.9343) and (2) (with a correlation coefficient of 0.8620).…”

“…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.…”