Cyanoacetic Acid Research Articles

Organic dyes incorporating N-functionalized pyrrole as conjugated bridge for dye-sensitized solar cells: Convenient synthesis, additional withdrawing group on the π-bridge and the suppressed aggregation

Two new N-functionalized pyrrole-based organic dyes were designed and synthesized for dye-sensitized solar cells. In addition to the normal acceptor of cyanoacetic acid moieties, another electron-withdrawing group, pentafluorophenyl or cyanophenyl one, was linked to the nitrogen atom of the pyrrole ring, with the aim to both suppress the aggregation of the dyes on the TiO2 surface and expand the electronic absorption spectra. As a result, dye LI-6 with pentafluorophenyl group as the auxiliary acceptor showed remarkable power conversion efficiencies of up to 6.23%, under AM 1.5G simulated solar light (100 mW/cm2), while that of N719 was tested to be 7.83% at the same measuring conditions.

ChemInform Abstract: Carboxylic Acid‐Catalyzed One‐Pot Synthesis of Cyanoacetylureas and Their Cyclization to 6‐Aminouracils in Guanidine Ionic Liquid.

ChemInformVolume 44, Issue 29 Heterocyclic Compounds ChemInform Abstract: Carboxylic Acid-Catalyzed One-Pot Synthesis of Cyanoacetylureas and Their Cyclization to 6-Aminouracils in Guanidine Ionic Liquid. Sunil S. Chavan, Sunil S. Chavan Dep. Pharm. Sci. Technol., Inst. Chem. Technol., Matunga, Mumbai 400 019, IndiaSearch for more papers by this authorRupesh U. Shelke, Rupesh U. Shelke Dep. Pharm. Sci. Technol., Inst. Chem. Technol., Matunga, Mumbai 400 019, IndiaSearch for more papers by this authorMariam S. Degani, Mariam S. Degani Dep. Pharm. Sci. Technol., Inst. Chem. Technol., Matunga, Mumbai 400 019, IndiaSearch for more papers by this author Sunil S. Chavan, Sunil S. Chavan Dep. Pharm. Sci. Technol., Inst. Chem. Technol., Matunga, Mumbai 400 019, IndiaSearch for more papers by this authorRupesh U. Shelke, Rupesh U. Shelke Dep. Pharm. Sci. Technol., Inst. Chem. Technol., Matunga, Mumbai 400 019, IndiaSearch for more papers by this authorMariam S. Degani, Mariam S. Degani Dep. Pharm. Sci. Technol., Inst. Chem. Technol., Matunga, Mumbai 400 019, IndiaSearch for more papers by this author First published: 01 July 2013 https://doi.org/10.1002/chin.201329181Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat No abstract is available for this article. Volume44, Issue29July 16, 2013 RelatedInformation

Influence of different acceptor groups in julolidine-based organic dye-sensitized solar cells

Two novel organic dyes containing julolidine as the electron donor and cyanoacetic acid or rhodanine-3-acetic acid as the electron acceptor bridged by bithiophene unit were synthesized. The absorption spectra, electrochemical and photovoltaic properties of the new dyes were extensively investigated. Transient absorption spectra measurements show that both sensitizers are quickly regenerated and the dye cations are efficiently intercepted by the redox mediator. The overall conversion efficiencies of 2.6% and 2.0% were obtained for dye-sensitized solar cells (DSSC) based on the cyanoacetic acid and rhodanine derived dyes, respectively. Compared with the rhodanine terminated dye, the open circuit voltage and the conversion efficiency of solar cell based on the cyanoacetic acid dye are increased about 25% and 30%, respectively. The lower efficiency of solar cell based on rhodanine is mainly resulted from the broken delocalization of the excited state due to the NCH2CO2H anchor, which affects the electron injection from the rhodanine terminated dye to the conduction band of TiO2.

Synthesis of N,N′-bis[4-(1H-1,2,3-triazol-1-yl)furazan-3-yl]-methylenediamine derivatives

[3+2] Cycloaddition of azide groups of N,N′-bis(4-azidofurazan-3-yl)methylenediamine to 1,3-dicarbonyl compounds and malonodinitrile was shown to proceed regioselectively with the formation of the corresponding N,N′-bis[4-(1H-1,2,3-triazol-1-yl)furazan-3-yl]methylenediamine derivatives. The reactions of N,N′-bis(4-azidofurazan-3-yl)methylenediamine with cyanoacetic acid ethyl ester and amide led to the formation of the product of transformation of the azide group in the starting compound to the amino groups.

Novel organic dye employing dithiafulvenyl-substituted arylamine hybrid donor unit for dye-sensitized solar cells

In order to increase electron-donating ability of the donor part of the organic dye, two dithiafulvenyl (DTF) units were introduced into a triphenylamine unit to form dithiafulvenyl-substituted triphenylamine hybrid donor for dye-sensitized solar cells (DSSCs) for the first time. Novel donor–acceptor organic dye WD-10 containing this hybrid donor and 2-cyanoacetic acid acceptor has been designed, synthesized and applied in DSSCs. The influence of the substituent unit DTF in the dye on the device performance has been investigated. It was found that the dye with dithiafulvenyl-substituted triphenylamine hybrid donor gave higher photocurrent, open-circuit voltage, and efficiency value. The DSSC based on organic dye WD-10 displayed a short-circuit current (Jsc) of 9.58mAcm−2, an open-circuit voltage (Voc) of 648mV, and a fill factor (ff) of 0.71, corresponding to an overall conversion efficiency of 4.41%. An increase in η of about 79% was obtained from simple triphenylamine dye L0 to WD-10. The different photovoltaic behaviors of the solar cells based on the organic dyes were further elucidated by the electrochemical impedance spectroscopy. This work identifies that the introduction of DTF unit into the simple triphenylamine dye could significant improve the photovoltaic performance.

Tuning the electronic structures and related properties of Ruthenium-based dye sensitizers by ligands: A theoretical study and design

The geometries, electronic structures, and absorption properties of three heteroleptic ruthenium complexes for dye-sensitized solar cells (DSCs), including Ru(L)(L1)(NCS)2 [L=4,4′-dicarboxylic acid-2,2′-bipyridine, Ru-T1: L1=(E)-2-(4′- methyl-2,2′-bipyridin-4-yl)-3-(thiophen-2-yl)acrylonitrile, Ru-T2: L2=(E)-3-(5′- hexyl-2,2′-bithiophen-5-yl)-2-(4′-methyl-2,2′-bipyridin-4-yl)acrylonitrile, and Ru-T3: L3=(E)-3-(5″-hexyl-2,2′:5′, 2″-terthiophen-5-yl)-2-(4′-methyl-2,2′-bipyridin-4-yl) acrylonitrile)], were investigated by using density functional theory (DFT) and time dependent DFT. The absorption of Ru-T1 in visible region mixed the character of metal-to-ligand charge transfer (MLCT) and ligand-to-ligand charge transfer (LLCT), while the absorption of Ru-T2 and Ru-T3 mixed MLCT, LLCT, and local excitation. Through the introduction of the 3-(5-hexyloligothiophen-5-yl) acrylonitrile group extended the conjugation length of the bipyridine donor ligand of Ru-complexes, the overlap between the ground state and excited states were enhanced, and their molar absorption coefficients were improved. However, the smaller shorter-circuit current densities of Ru-T2 and Ru-T3 were resulted from the excited states with the character of not-effective charge transfer. The 11 kinds of Ru-complexes were designed by removing CN group, substituting of COOH with cyanoacetic acid, and increasing thiophene units. The analysis of excited states and oxidation potential suggest that several designed dyes may have good performance in DSCs.

2-Cyanoacetamide

Cyanoacetic acid derivatives are important intermediates in the synthesis of various organic heterocyclic compounds. Among these derivatives, 2-cyanoacetamide deserves attention since it is a useful reagent for the synthesis of a variety of novel compounds possessing ­biological activity and other special properties.[1]

Synthesis of 6-(2-hydroxyaryl)-2-pyridones by the reaction of chromones with cyanoacetic, acetoacetic, and malonic acid amides

A reaction of chromones with cyanoacetic, acetoacetic, and malonic acid amides in the presence of sodium ethoxide furnished a number of new 3-substituted 6-(2-hydroxyaryl)-2-pyridones in good yields, including those containing a polyfluoroalkyl group at position 4.

ChemInform Abstract: Synthesis of New Substituted Pyridopyrazolotriazines

Abstractbased on reactions of pyrazolopyridinyldiazonium chlorides (I) with a variety of active methylene compounds

Catalytic Enantioselective Decarboxylative Cyanoalkylation of Imines by Using Palladium Pincer Complexes with C2‐Symmetric Chiral Bis(imidazoline)s

Manifold products: The enantioselective decarboxylative Mannich-type reaction of cyanoacetic acid with N-(2-pyridinesulfonyl)imines catalyzed by chiral 1,3-bis(imidazolin-2-yl)benzene (Phebim)-Pd(II) complexes afforded products with good enantioselectivity (see scheme). The reaction was applied to a wide range of imines with good yield and enantioselectivity. The obtained products can be converted into various compounds without the loss of enantiopurity.

Influence of different anchoring groups in indoline dyes for dye-sensitized solar cells: Electron injection, impedance and charge recombination

For developing panchromatic dyes, we focus on the effect of rhodanine acceptor on photovoltaic performances in D-π-A indoline dye. Upon changing from cyanoacetic acid (dye C-CA) to rhodanine-3-acetic acid (dye C-RA) as acceptor and anchoring group, C-RA shows broader absorption band, which can overlap with the solar spectrum more preferably. However, the power conversion efficiency of DSSCs based on C-RA (0.57–0.90%) is one order of magnitude with respect to C-CA (8.49%). The distinct difference of IPCE values between C-CA and C-RA is predominately attributed to the different excited electron injection yield (Φinj). The relatively short excited electron lifetime and the isolation of LUMO orbital from anchoring group in C-RA result in the low photo-excited electron injection efficiency with low JSC. Moreover, with respect to C-CA, the systematic SLIT and EIS studies demonstrate that C-RA possesses the relatively low injection charge density in the TiO2 electrode and fast charge recombination rate, leading to a low VOC. Our studies are highly helpful to the design of novel metal-free D-π-A organic sensitizers, especially for those using rhodanine-3-acetic acid as acceptor.

Cyanomethylbenzoic Acid: An Acceptor for Donor–π–Acceptor Chromophores Used in Dye‐Sensitized Solar Cells

Sensing the sun: Incorporation of a cyanomethyl benzoic acid electron acceptor into donor-π-acceptor sensitizers for dye-sensitized-solar cell is shown to lead to devices with improved conversion efficiency when compared with more widely used cyanoacetic acid acceptor.

Fluorine–thiophene-substituted organic dyes for dye sensitized solar cells

Novel triphenylamine (TPA)-based organic dyes were synthesized and assessed for their performance in dye-sensitized solar cells (DSSCs). In the dyes considered the TPA group and the cyanoacetic acid have the role of electron-donor and -acceptor, respectively, whereas a thienyl–fluoro-phenyl-substituted was introduced as π-linker to improve the dye performance in DSSCs. Experimental characterizations empasize that the presence of electron withdrawing substituents in the linker close to the electron-acceptor moiety leads to a more efficient intramolecular photoinduced charge transfer. In fact, photovoltaic experiments reveal that the DSSCs based on the thienyl–o-fluoro-phenyl substituted dyes yield a better solar-energy-to-electricity conversion efficiency.

Starburst triarylamine based dyes bearing a 3,4-ethylenedioxythiophene linker for efficient dye-sensitized solar cells

Starburst triarylamine-based organic dyes (D1, D2, and D3) have been synthesized. For the three designed dyes, the starburst triarylamine group, thiophene (or 3,4-ethylenedioxythiophene), and cyanoacetic acid take the role of electron donor, π-conjugation bridge, and electron acceptor, respectively. These compounds are characterized by photophysical, electrochemical, and theoretical computational methods. Nanocrystalline TiO2-based dye-sensitized solar cells were fabricated using these molecules as light-harvesting sensitizers. The overall efficiencies of the sensitized cells range from 5.48 to 6.15%. It was found that the introduction of the EDOT group in D3 bathochromically extended the absorption spectra, resulting in a leap in the photovoltaic performance in comparison to D2. Incorporation of a hydrophobic carbazole-containing segment at D2 relative with D1 retarded the electron transfer from TiO2 to the oxidized dye or electrolyte, leading to an increase of electron lifetime.

D–π–A structured porphyrins for efficient dye-sensitized solar cells

In this study, new push–pull alkoxy-wrapped zinc porphyrin dyes with intramolecular donor–π–acceptor structures have been designed and synthesized for dye-sensitized solar cells (DSCs). The linkers based on thiophene or 2,3-dihydrothieno[3,4-b][1,4] dioxine with cyanoacetic acid can broaden the spectral response of porphyrins into the near-IR region (∼850 nm), which is mainly attributed to the cyanoacetic acid group. However, porphyrins with cyanoacrylic acid as an anchoring group lead to a faster charge recombination rate at the dye-sensitized heterojunction interface, which lowers the device photovoltaic performance. By using porphyrins with a rigid π-linker feature structure that is 5-ethynylthiophene-2-carboxylic acid, highly efficient DSC devices with a power conversion efficiency of 9.5% can be obtained. Spectral, electrochemical, photovoltage transient decay and impedance measurements are performed to reveal the influence of π-conjugated linkers and anchoring groups upon the optoelectronic features of porphyrin dyes in DSCs.

Synthesis and Photoelectric Properties of Coumarin Type Sensitizing Dyes

Two novel coumarin type sensitizing dyes were synthesized with coumarin group bearing electron-donating group as donor, thiophene as π bridge and cyanoacetic acid as acceptor. Their spectral, electrochemical and photoelectric properties were evaluated. The results suggest that both dyes have the molecular orbital energy matched with the conduction band of TiO2 and the redox potential of the electrolyte I2/I -, which ensures the production of the current cycle in the cell. Compared with 2-cyano-3-[5-(7-methoxy-2-oxo-2H-chromen-3-yl)thiophen-2-yl]acrylic acid (IIIb) bearing methoxy group, sensitizing dye 2-cyano-3-[5-(7-diethylamino-2-oxo-2H-chromen-3-yl)thiophen-2-yl]acrylic acid (IIIa) bearing diethylamino group on C-7 of coumarin ring shows improved absorption of intramolecular charge transfer and the red shift of UV spectra. Dye sensitized solar cell (DSSC) based on IIIa has reduced back current and better IPCE (incident photo-to-current conversion efficient) and Jsc, which leads to improved photoelectric conversion efficiency (Jsc=8.68 mA/cm, Voc=574 mV, η=3.52%).

Bibridged bianchoring metal-free dyes based on phenoxazine and triphenyl amine as donors for dye-sensitized solar cell applications

The design and synthesis of two new metal-free bibridged bianchoring ambipolar dyes (D–(π–A)2) by linking electron-donating triphenyl amine or phenoxazine and electron-accepting cyanoacetic acid through a cyanovinyl thiophene π-bridge for fabrication of metal-free, dye-sensitized solar cells (DSSCs). The structures of the synthesized dyes were confirmed by NMR, mass spectrometry and elemental analysis. Experimental and theoretical (DFT) approaches revealed that the phenoxazine (POX-th-CN) dye exhibits a lower band gap (2.03 eV) compared to the triphenyl amine (TPA-th-CN) dye (2.19 eV). Due to this lower band gap, the electronic absorption of the phenoxazine dye becomes red-shifted, and, in addition, the fabricated dye-sensitized solar cell device based on this dye shows higher current conversion efficiencies (η = 1.78%) compared to the TPA-th-CN dye.

Highly Efficient Method for Synthesis of N-Amino-2-Pyridone Derivatives in the Presence of Catalysts such as Magnesium Oxide (MgO) and Bismuth(III) Nitrate Pentahydrate (Bi(NO<sub>3</sub>)<sub>3</sub>·5H<sub>2</sub>O)

Magnesium oxide (MgO) and bismuth(III) nitrate pentahydrate as highly effective catalysts which have catalyzed the three-component reaction of cyanoacetic acid hydrazide, aldehydes and malononitrile to prepare of the corresponding N-amino-2-pyridones. These catalysts are inexpensive and easily obtained, stable and storable, easily recycled and reused for several cycles with consistent activity.

A novel compact DPP dye with enhanced light harvesting and charge transfer properties for highly efficient DSCs

A novel compact diketopyrrolopyrrole (DPP) dye was designed and synthesized using DPP core as a bridge to connect bis(4-tert-butylphenyl)phenylamine and cyanoacetic acid units with the D–π–A configuration, and employed as a sensitizer in dye-sensitized solar cells, giving a high power conversion efficiency of 8.61% under AM 1.5 conditions.

ChemInform Abstract: Synthesis of Nitrocyclopropanedicarboxylic Acid Derivatives by Addition of α‐Bromonitroalkanes to Methylidene Malonic, Methylidene Cyanoacetic or Maleic Acid Derivatives.

AbstractThe stereochemical implications of the title reaction are discussed.