Heteromerous Bistricyclic Aromatic Enes: Dynamic Stereochemistry of Xanthylidene‐Anthrones

Suissa, M. Rachel; Cohen, Shmuel; Pogodin, Sergey; Agranat, Israel

doi:10.1002/chir.22500

Cited by 3 publications

(2 citation statements)

References 39 publications

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“…9 – 48 , 53 , 54 ). Note that 1 H NMR spectra exhibit one major peaks set of one isomer and another minor peaks set of the other isomer 2 , 21 – 25 . Except for 5f , all other Ph-F’As 5a – e had exceptionally high crystallinity.…”

Section: Resultsmentioning

confidence: 99%

Equilibrium and thermodynamic studies of chromic overcrowded fluorenylidene-acridanes with modified fluorene moieties

Wang

Ogumi

et al. 2020

Commun Chem

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Chromic materials, an important class of stimuli-responsive materials, have aroused extensive attention in recent years. Normally, their color is based on changes in morphology. Few examples of chromic material based on conformational isomerization, such as in overcrowded alkenes, have been reported previously. Furthemore, experimental thermodynamic studies of overcrowded bistricyclic aromatic enes have not been carried out to our knowledge. Here, we show that N-phenyl-substituted fluorenylidene-acridanes, with a properly modified fluorene moiety, performs chromisms originating from conformational changes. Thermodynamic studies determine equilibrium constants, changes in enthalpy, entropy, and free energy in solution, enabling in-depth understanding of the equilibrium behavior of overcrowded alkenes and providing useful information for designing functional chromic compounds. Single-crystal X-ray diffraction analysis of fluorenylidene-acridanes in this work clearly shows well-tuned charge transfer from the acridane to the fluorene moiety. Various chromic behaviors such as mechanochromism, thermochromism, solvatochromism, vapochromism, and proton-induced chromism also support understanding of conformational isomerism.

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Section: Resultsmentioning

confidence: 99%

Equilibrium and thermodynamic studies of chromic overcrowded fluorenylidene-acridanes with modified fluorene moieties

Wang

Ogumi

et al. 2020

Commun Chem

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“…Table 1 gives crystallographic data of 15, 20, and 21 [68]. Table 2 [69], and 58 [70], for comparison. Geometrical parameters are defined as follows [3][4][5]: pure ethylenic twist x around C 9 =C 9 0 is the average value of the torsion angles C 9a -C 9 -C 9 0 -C 1 0 and C 8a -C 9 -C 9 0 -C 1 00 ; fold / of the tricyclic moiety is the dihedral angle between the least-square planes of the carbon atoms C 1 , C 2 , C 3 , C 4 , C 4a , C 9a and C 5 , C 6 , C 7 , C 8 , C 8a , C 10a of the benzene rings of each tricyclic moiety; pyramidalization angles v(C 9 ) and v(C 9 0 ) are the improper torsion angles C 9a -C 9 -C 9 0 -C 8a and C 1 0 -C 9 0 -C 9 -C 1 00 , respectively, -180°.…”

Section: Molecular and Crystal Structuresmentioning

confidence: 99%

Selenium- and tellurium-bridged heteromerous overcrowded bistricyclic aromatic enes with central six-member and seven-member rings

et al. 2015

Self Cite

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A series of selenium-bridged and telluriumbridged heteromerous bistricyclic aromatic enes (BAEs) 15-25 with six-member and seven-member central rings have been synthesized by Barton-Kellogg olefination, twofold extrusion coupling method between tricyclic aromatic thiones and tricyclic aromatic diazo derivatives. The crystal structures of thioxanthenylidene-anthracenone (15), selenoxanthenylidene-anthracenone (20), and telluroxanthenylidene-anthracenone (21) were determined. The ordered crystal structure of 21 showed a very high degree of folding of the telluroxanthenylidene moiety (58.5°) and very short intramolecular TeÁÁÁC 9 0 contact distance, indicating [20 % penetration which may reflect secondary nonbonding interactions and lack of aromatic telluroxanthenylium-anthracenolate contribution. The BAEs were subjected to a 1 H-, 13 C-, 77 Se-, and 125 Te-NMR spectroscopic study. The 1 H-NMR spectra indicated anti-folded conformations in solution. The measured pronounced downfield 77 Se-and 125 Te-NMR shifts in 20 and 21, relative to the corresponding spectra of homomerous BAEs diselenoxanthylene (7) and ditelluroxanthylene (8), may be due to the proximity of the Se and Te bridges to the carbons of the central enes in the anti-folded conformations. This deshielding effect was larger in 21 than in 20, d( 125 Te)/d( 77 Se) = 1.53, a ratio higher than in any other member of the series.

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Synthesis of bistricyclic aromatic enes and related polycyclic systems via Pd-catalyzed tandem Suzuki coupling/Heck cyclization reaction

Li,

Zhu,

zhao

et al. 2024

Tetrahedron Letters

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Heteromerous Bistricyclic Aromatic Enes: Dynamic Stereochemistry of Xanthylidene‐Anthrones

Cited by 3 publications

References 39 publications

Equilibrium and thermodynamic studies of chromic overcrowded fluorenylidene-acridanes with modified fluorene moieties

Equilibrium and thermodynamic studies of chromic overcrowded fluorenylidene-acridanes with modified fluorene moieties

Selenium- and tellurium-bridged heteromerous overcrowded bistricyclic aromatic enes with central six-member and seven-member rings

Synthesis of bistricyclic aromatic enes and related polycyclic systems via Pd-catalyzed tandem Suzuki coupling/Heck cyclization reaction

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