Dicyanobenzene and dicyanopyrazine derived X-shaped charge-transfer chromophores: comparative and structure–property relationship study

Dokládalová, Lenka; Bureš, Filip; Kuźnik, W.; Kityk, I.V.; Wojciechowski, A.; Mikýsek, Tomáš; Almonasy, Numan; Manikannan, Ramaiyan; Padělková, Zdeňka; Kulhánek, Jiří; Ludwig, Miroslav

doi:10.1039/c4ob00901k

Cited by 30 publications

(10 citation statements)

References 53 publications

(28 reference statements)

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“…Figure shows their molecular structures, see the SI for more information. In accordance to our previous observations on pyrazine‐2,3‐dicarbonitriles,, the thiophene rings directly attached to pyrazine positions 5 and 6 in compounds 1 , 2 , and 5 are significantly twisted above/below the pyrazine plane with torsion angles 8–40 °. This is most likely caused by repulsion of the hydrogen atoms of both appended thiophene rings and also results in angular arrangement of the parent pyrazine core (see the side view of 1 provided in Figure ).…”

Section: Resultssupporting

confidence: 92%

Structure‐Catalytic Activity in a Series of Push‐Pull Dicyanopyrazine/Dicyanoimidazole Photoredox Catalysts

et al. 2018

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A series of dicyanopyrazine and dicyanoimidazole derived push‐pull molecules have been prepared and further investigated as photoredox catalysts. The fundamental properties of the catalysts were studied by DSC, X‐ray analysis, absorption/emission spectra, and electrochemistry and were completed with the DFT results. The catalytic activity has been evaluated in visible light induced α‐functionalization of amines (cross‐dehydrogenative coupling and annulation reaction of tetrahydroisoquinolines). Thorough structure‐property‐catalytic activity relationships were elucidated. The developed series of tailored organic photoredox catalysts allows synthetic chemists to perform desired reactions under sustainable and mild conditions employing solely visible light as a source of energy.

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Section: Resultssupporting

confidence: 92%

Structure‐Catalytic Activity in a Series of Push‐Pull Dicyanopyrazine/Dicyanoimidazole Photoredox Catalysts

et al. 2018

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“…Based on our recent contributions, dicyano-substituted (hetero)aromatic acceptor units based on imidazole, benzene and pyrazine can be compared with barbituric acid here. Yshaped dicyanoimidazole (DCI), 32 X-shaped dicyanobenzene (DCB) 86 and dicyanopyrazine (DCP), 23 as well as N,N 0 -dibutylbarbituric acid (BA) 87 derivatives 2c and 65-67 saturated by one or two DMA donor(s), can be chosen as model push-pull molecules (Fig. 35).…”

Section: Tuning Through the Acceptormentioning

confidence: 99%

Fundamental aspects of property tuning in push–pull molecules

2014

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Property tuning in selected examples of D-p-A molecules has been discussed and summarized in this review article. The tuning and structure-property relationships have been demonstrated on the particular A, p and D parts of the push-pull molecule. Special emphasis has been put on the tuning of the FMO levels and optical properties. Further prospective applications of the given chromophore have also been considered.

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“…The standard reaction conditions (1,4-dioxane/K 2 CO 3 ) were slightly modified, as a small amount of acetonitrile was added to provide better solubility of the dicyanonaphthalene precursor. Pd(PPh 3 ) 2 Cl 2 as catalyst instead of Pd 0 salts allowed us to shorten the reaction time from 13 to 6 h [48][49][50][51][52]. All compounds were characterized by nuclear magnetic resonance spectroscopy (NMR, Supporting Information File 1, Figures S1-S24) as well as exact electrospray mass spectrometry (EM-ESIMS, Supporting Information File 1, Figures S25-S30) and appear as white to faint yellow solids.…”

Section: Synthesis and Structural Characterizationmentioning

confidence: 99%

Naphthalonitriles featuring efficient emission in solution and in the solid state

Sailaja¹,

Maisuls²,

Kösters³

et al. 2020

Beilstein J. Org. Chem.

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In this work, a series of γ-substituted diphenylnaphthalonitriles were synthesized and characterized. They show efficient emission in solution and in the aggregated state and their environment responsiveness is based on having variable substituents at the para-position of the two phenyl moieties. The excited state properties were fully investigated in tetrahydrofuran (THF) solutions and in THF/H2O mixtures. The size of the aggregates in aqueous media were measured by dynamic light scattering (DLS). The steady-state and time-resolved photoluminescence spectroscopy studies revealed that all the molecules show intense fluorescence both in solution and in the aggregated state. In THF solutions, a blue emission was observed for the unsubstituted (H), methyl- (Me) and tert-butyl- (t-Bu) substituted γ-diphenylnaphthalonitriles, which can be attributed to a weak π-donor capability of these groups. On the other hand, the methoxy- (OMe), methylsulfanyl- (SMe) and dimethylamino- (NMe2) substituted compounds exhibit a progressive red-shift in emission compared to H, Me and t-Bu due to a growing π-electron donating capability. Interestingly, upon aggregation in water-containing media, H, Me and t-Bu show a slight red-shift of the emission and a blue-shift is observed for OMe, SMe and NMe2. The crystal structure of Me allowed a detailed discussion of the structure–property relationship. Clearly, N-containing substituents such as NMe2 possess more electron-donating ability than the S-based moieties such as SMe. Moreover, it was found that NMe2 showed higher luminescence quantum yields (ΦF) in comparison to SMe, indicating that N-substituted groups could enhance the fluorescence intensity. Therefore, the π-donor nature of the substituents on the phenyl ring constitutes the main parameter that influences the photophysical properties, such as excited state lifetimes and photoluminescence quantum yields. Hence, a series of highly luminescent materials from deep blue to red emission depending on substitution and environment is reported with potential applications in sensing, bioimaging and optoelectronics.

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Dicyanobenzene and dicyanopyrazine derived X-shaped charge-transfer chromophores: comparative and structure–property relationship study

Cited by 30 publications

References 53 publications

Structure‐Catalytic Activity in a Series of Push‐Pull Dicyanopyrazine/Dicyanoimidazole Photoredox Catalysts

Structure‐Catalytic Activity in a Series of Push‐Pull Dicyanopyrazine/Dicyanoimidazole Photoredox Catalysts

Fundamental aspects of property tuning in push–pull molecules

Naphthalonitriles featuring efficient emission in solution and in the solid state

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