- Nonlinear optical chromophores containing a novel pyrrole-based bridge: Optimization of electro-optic activity and thermal stability by modifying the bridge
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Three novel second order nonlinear optical chromophores based on julolidinyl donors and tricyanovinyldihydrofuran (TCF) acceptors linked together via modified pyrrole π-conjugation (chromophores A and B) or thiophene moieties (chromophore C) as the bridges have been synthesized and systematically characterized. In particular, the pyrrole moiety bridge has been modified with the electron withdrawing group (-Br, -NO2) substituted benzene ring. The introduction of side phenyl groups to chromophores A and B can increase the thermal and chemical stability and reduce dipole-dipole interactions so as to translate their hyperpolarizability (β) values into bulk EO performance more effectively than chromophore C. Moreover, DFT calculations suggested that the additional electron withdrawing groups in chromophores A and B could increase the β value compared to that of chromophore D without substituted phenyl groups, and they showed different influences on the solvatochromic behavior, thermal stability, and electro-optic activity of the chromophores. EO responses (r33 values) of guest-host polymers containing pyrrole-bridged chromophores were reported. Incorporation of chromophores A and B into APC provided large electro-optic coefficients of 86 and 128 pm V-1 at 1310 nm with a high loading of 30 wt%. Film-C/APC containing 25 wt% of chromophore C provides an EO coefficient of 98 pm V-1.
- Liu, Fenggang,Wang, Haoran,Yang, Yuhui,Xu, Huajun,Zhang, Maolin,Zhang, Airui,Bo, Shuhui,Zhen, Zhen,Liu, Xinhou,Qiu, Ling
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- An improved preparation method of benzyl and thenyl triphenylphosphonium salts
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New benzyl and thenyl phosphonium salts have been prepared by an improved method in solution from the parent alcohols and triphenylphosphine hydrobromide. Benzyl-type alcohols containing a tertiary amine can also be converted within high yields to phospho
- Zhang, Jian-Xin,Dubois, Philippe,Jerome, Robert
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Read Online
- Organic second-order nonlinear optical chromophore, synthetic method and application
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The invention discloses an organic second-order nonlinear optical chromophore, a synthetic method and an application. The organic second-order nonlinear optical chromophore is provided with a structure of a Formula (CL) or Formula (HCL): FORMULA, wherein G is H, para-alkoxyphenyl, thienyl, or para-dialkyl aminophenyl; R1 is alkyl, benzyl, and halogenated alkyl; R2 is methyl or trifluoromethyl; R3 is alkyl, phenyl, replaced phenyl, replaced thienyl or hydroxyalkyl. The organic second-order nonlinear optical chromophore with D-Pi-A structure has simple synthetic step and high preparation yield; besides, it has good solubility in the most organic solvent and high thermal stability; the organic second-order nonlinear optical chromophore can be widely applied to the field of optical information material.
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Paragraph 0083; 0088; 0089; 0108; 0113
(2017/05/05)
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- Containing Trypticene rigid three-dimensional structure chromophore molecule and its synthetic method and application
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The invention relates to a chromophore molecule containing a triptycene rigid stereochemical structure and a synthetic method thereof, and an application of the chromophore molecule containing the triptycene rigid stereochemical structure in a polymer ele
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Paragraph 0063; 0065; 0075-0076
(2017/01/19)
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- Synthesis, spectral properties and photobehaviour of push-pull distyrylbenzene nitro-derivatives
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Six novel asymmetric 2,5-distyryl-furan, 2,5-distyryl-thiophene and 2,6-distyrylpyridine derivatives, bearing an electron acceptor (p-nitro) group at one side and an electron donor (p-methoxy or p-dimethylamino) group at the other side, have been prepared. The experimental absorption properties have been measured and compared with the computed parameters. Theoretical and experimental results indicate that one conformational isomer (the compressed one) is largely prevalent in all compounds. The measured radiative and reactive relaxation properties of these donor/acceptor disubstituted compounds were also compared with those of the unsubstituted analogues previously investigated. The presence of the donor/acceptor groups leads to a significant increase of the charge transfer character of both the ground and the excited states and to strong red shifts of the absorption spectra, an effect that can be useful for potential applications in material science. The fluorescence/photoisomerization competition of the furan and thiophene derivatives was found to be rather similar to that of the unsubstituted analogues whereas significant changes were found for the pyridine derivatives where a drastic decrease of fluorescence, a sizable increase of photoisomerization and a predominance of radiationless deactivation to the ground state becomes operative.
- Kika?,Carlotti,?kori?,?indler-Kulyk,Mazzucato,Spalletti
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experimental part
p. 38 - 46
(2012/09/10)
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- Push-pull structures with a pyrazine core and hexatriene chain: synthesis and light-emitting properties
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In this paper, we describe the synthesis of various push-pull molecules with a central pyrazine unit connected to a hexatriene chain terminated by various p-substituted phenyl groups. The key steps involve metallation and subsequent transmetallation of 2-
- Hebbar, Nordine,Ramondenc, Yvan,Plé, Gérard,Dupas, Georges,Plé, Nelly
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body text
p. 4190 - 4200
(2009/09/30)
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- Effect of base on alkyltriphenylphosphonium salts in polar aprotic solvents
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When arylmethyl phosphonium salts are treated with a base (e.g., t-BuOK or NaH) they homocouple to form symmetric 1,2-diarylethenes. In some cases, dilution and (or) use of excess base lead to very high yields of the product. This reaction is solvent sensitive: the reaction occurs only when polar aprotic solvents such as acetonitrile or DMSO are used. Other alkyl phosphonium salts (e.g., ethoxycarbonylmethyltriphenylphosphonium bromide and n- butyltriphenylphosphonium bromide) form a ylid (when an α-carbonyl group is present) or lose a phenyl group to form alkyldiphenylphosphine oxides when treated with the base. Mechanistic investigation of the homocoupling reaction indicates that the reaction proceeds through a ylid that acts as a nucleophile on an unreacted phosphonium salt. The resulting adduct undergoes elimination to form the observed product. The EIZ ratio seems to depend on the amount of the base used and the phosphonium salt involved.
- Ngwendson, Julius N.,Schultze, Cassandra M.,Bollinger, Jordan W.,Banerjee, Anamitro
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p. 668 - 675
(2008/09/21)
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- Synthesis and nonlinear optical absorption properties of two new conjugated ferrocene-bridge-pyridinium compounds
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Two electron donor-π-acceptor (D-π-A) chromospheres, with ferrocene as the electron donor and pyridinium as the electron acceptor, were synthesized. The nonlinear optical absorption (NOA) properties in the solution state were investigated by the Z-scan technique. Both compounds exhibited reverse saturable absorption (RSA) and optical limiting effect under nanosecond pulse irradiation.
- Yang, Fan,Xu, Xiu-Ling,Gong, Yong-Hua,Qiu, Wen-Wei,Sun, Zhen-Rong,Zhou, Jin-Wei,Audebert, Pierre,Tang, Jie
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p. 9188 - 9194
(2008/02/10)
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- A convenient synthesis of symmetric 1,2-diarylethenes from arylmethyl phosphonium salts
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Symmetric ethenyldithiophenes are important intermediates for synthesis of photochromic materials and organic conductors. When acetonitrile is used as a solvent, 3-methylthiophenylphosphonium salts form symmetric ethenyldithiophenes in the presence of a strong base (e.g., NaH, tBuOK) in moderate to high yields. This homocoupling reaction is faster than a Wittig reaction with aromatic ketones in acetonitrile. Our study shows that the presence of polar aprotic solvents promotes the homocoupling reaction.
- Ngwendson, Julius N.,Atemnkeng, Walters N.,Schultze, Cassandra M.,Banerjee, Anamitro
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p. 4085 - 4088
(2007/10/03)
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- Trivalent Boron as an Acceptor in Donor - π - Acceptor-Type Compounds for Single- and Two-Photon Excited Fluorescence
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The synthesis, structure, and fluorescence properties of a series of new donor - π - acceptor (D - π - A) type compounds, with a trivalent boron, protected by two mesityl groups, as acceptor, and with various typical donors and different π-conjugated bridges, are reported. All these stable organoboron compounds show intense single-photon excited fluorescence (SPEF) and two-photon excited fluorescence (TPEF) in a wide spectral range from blue to green, with the spectral peak position of the SPEF being basically the same as that of the TPEF. The remarkably strong C-B(mesityl)2 bonding, and the well-conjugated π-system, shown in X-ray crystal structures of two compounds, indicate some charge transfer features of the ground state. Meanwhile, spectral data indicate that the charge transfer from donor to acceptor is greatly enhanced in the excited states. Based on typical structural data and comprehensive spectral data, the following structure - property relationships can be drawn: 1) the moderate arylamino donor can more effectively enhance the SPEF and TPEF intensities than can the strong alkylamino donor; 2) stilbene is a better π-bridge than styrylthiophene for its capability of enhancing and blue-shifting the SPEF and TPEF of the corresponding D - π - A compounds; and 3) when compared to its boron-free precursors and other analogues, -B(mesityl)2 invariably and consistently acts as an effective SPEF and TPEF fluorophore in all this series of organoboron compounds, which may result from its strong π -electron-withdrawing and charge transfer-inducing nature in the ground-state and, more dominantly, in the excited-state. Combining all the above positive structure factors, trans-4′-N,N-diphenylamino-4-dimesitylborylstilbene (compound 3) stands out as the optimized green SPEF and TPEF emitter. This compound exhibits an SPEF quantum yield φ of 0.91 at 522 nm in THF, a TPEF cross-section σ′ that is an order of magnitude larger than that of its boron-free precursor upon excitation by 800 nm femto-second laser pulses, and a two-photon absorption section a of 3.0 × 10-48 cm 4 s. In the blue light region, trans-4′ -N-carbazolyl-4-dimesitylborylstilbene (compound 4) shows significant SPEF and TPEF properties, with φ = 0.79 at 464 nm in THF and a large σ′ value, which is five times that of fluorescein upon excitation by 740 nm femto-second laser pulses.
- Liu, Zhi-Qiang,Fang, Qi,Wang, Dong,Cao, Du-Xia,Xue, Gang,Yu, Wen-Tao,Lei, Hong
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p. 5074 - 5084
(2007/10/03)
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- Synthesis of aryl-terminated polyenaldehydes and polyenetriethoxysilanes for preparation of self-assembled monolayers on silicon surfaces
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The synthesis of αω-terminally functionalized polyenes with arenes or hetarenes at one end and either an aldehyde or a triethoxysilyl function at the other end, capable of reacting with H-terminated or oxidized silicon surfaces, is described. Analogous to known Wittig reactions, polyenedialdehydes 1 and 3, the latter derived from 1 and phosphonium chloride 2 in a twofold Wittig olefination, were converted with phosphonium bromides 4 to give the (all-E)-arylpolyenaldehydes 5 and 6. A terminal alkyl chain was introduced in dialdehydes 1a and 3a by reaction with P,P-didecyldibenzophospholium bromide 8, resulting in polyenals 9. Wittig olefination of 5c and 9a with phosphonium chloride 2 afforded the (2-thienyl)tridecahexaenal 7 and the docosahexaenal 10. With respect to monolayer formation on oxidized Si(100) surfaces, (9-anthryl)- and (2-thienyl)-ω-functionalized polyenetriethoxysilanes 16 and 17 were prepared in a reaction sequence involving the introduction of a terminal triple bond with [3-(trimethylsilyl)prop-2-ynyl]triphenylphosphonium bromide (11), desilylation of the resulting arylpolyeninetrimethylsilanes 12, 13 with Bu4NF·3H2O, and subsequent hydrosilylation of the arylpolyenines 14, 15 using triethoxysilane under dichlorocyclooctadienylplatinum(II) catalysis.
- Effenberger,Wezstein
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p. 1368 - 1376
(2007/10/03)
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- Flash vacuum pyrolysis of stabilised phosphorus ylides. Part 16. Model studies for the construction of conjugated polymers
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Reaction of a range of bis(ylides) with acid chlorides has been used to prepare the bis(oxoylides) 11-15. Similarly a range of simple ylides react with bis(acid chlorides) to give bis(oxoylides) 19-27 with the isomeric structure. Flash vacuum pyrolysis (FVP) of one example of the first type results in extrusion of Ph3P rather than the expected Ph3PO while six examples of the second type do extrude Ph3PO upon FVP at 500 °C to afford the bis(alkynes) 28. Examples of the corresponding bis(tributylphosphonium ylides) have also been prepared but attempts to construct a tetrakis(oxoylide) 31 using a stepwise approach were unsuccessful. Fully assigned 13C NMR spectra are presented for six of the bis(oxoylides).
- Aitken, R. Alan,Drysdale, Martin J.,Hill, Lawrence,Lumbard, Keith W.,Maccallum, James R.,Seth, Shirley
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p. 11039 - 11050
(2007/10/03)
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- Phenylpropyl-2,3-dihydrobenzofurans useful as anti-inflammatory agents
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Phenylalkyl-2,3-dihydrobenzofurans and analogs were prepared by (1) nucleophilic substitution involving an appropriately substituted 2,3-dihydrobenzofuranol (or 2,3-dihydrobenzopyranol) and a cinnamylhalide followed by reduction; or (2) by Wittig reaction
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