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The multicomponent condensation of cyclopentylidene- or cyclohexylidenemalononitrile, cyanoacetic acid amides or thioamides, and alkylating agents affords 4-spirocyclopentane- and 4-spirocyclohexanenicotinic acid nitriles and amides. The structures of several reaction products were determined by X-ray diffraction.

Developing organic dyes with di-/multi-anchors has aroused increasing attention in recent years due to these dyes had many advantages in comparison with the analogues of single acceptor. Herein, four (D–π–A)-L2-(A–π–D–π–A)2 dyes (TQ1−2, OQ1−2) along with a reference D−(π–A)2 dye (TD), comprising phenothiazine/phenoxazine as a donor, thiophene as a π space, cyanoacetic acid as an acceptor and saturated n-hexyl/n-dodecyl as a flexible linker have been prepared and characterized. The correlative between the variation of structure and the optical, electrochemical properties in addition to photovoltaic performances of the dyes have been explored. Besides, the ultraviolet–visible spectra in solution and on the TiO2 film, cyclic voltammetry, photocurrent-voltage scan, incident photon-to-current conversion efficiency and electrochemical impedance spectroscopic of the presented dyes have been investigated. Compared with the reference dye TD, TQ1−2 and OQ1−2 exhibit higher molar extinction coefficient, broader and stronger incident photon-to-current conversion efficiency response spectrum, and higher density of light-absorbing units adsorbed on the TiO2 surface. Among the cells based on the pristine dyes, the relatively high photocurrent of OQ1-2 by comparison with the counterparts of TQ1−2 is attributed to the incorporation of phenoxazine donor into the (A–π–D–π–A)2 units. An increase open-circuit voltage of TQ2 and OQ2 compared to TQ1 and OQ1 is ascribed to the higher charge recombination resistance and the longer electron lifetime in their cells. Consequently, a maximum power conversion efficiency of 6.77% is attained by the TQ2-based cells with iodide/triiodide electrolyte under the illumination of 100 mW cm−2.

Hexyl carbazole derivatives are one of the most prominent dye scaffolds in the dye-sensitized solar cells (DSSCs). New substituted carbazole dyes such as DRA-HC, DCA-HC, and DTC-HC were synthesized for DSSCs. These dyes are containing hexyl moiety as electron donor and rhodanine-3-acetic acid, cyanoacetic acid and tetracyanoethylene as an electron acceptor linked to carbazole moiety. The relation between dye structures, photophysical/electrochemical, molecular structure and DSSC manufacturing had been discussed. All structures showed more positive ground-state oxidation potential than I−/I−3 and more negative excited state oxidation potential than the conduction band edge of the semiconductor. The highest efficiency of the DSSCs was obtained in the case of DCA-HC dye (η = 1.41%, VOC = 708 mV, FF = 0.81, and JSC = 2.45 mA cm−2 with 100 mW cm−2) compared to other synthesized dyes.

Adsorption of corrosive SO2 gas occurs in metal-organic frameworks (MOFs) including UiO-66. Improvements in SO2 capacity is obtained through the incorporation of residual modulators in the UiO-66 f...

The recyclization of 2-{[5-aryl-2-oxofuran-3(2H)-ylidene]amino}thiophene-3-carboxylic acids with cyano-acetic acid derivatives in the presence of t-BuOK afforded potassium 1-cyano-3-{[5-R1-4-R2-3-(ethoxycarbonyl)-thiophen-2-yl]amino}-1-R3-5-oxo-5-arylpenta-1,3-dien-2-olates.

Novel metal free organic dyes coded TET(RA)4, TET(CA)4, and TET(QA)4 were designed, synthesized, and characterized as effective sensitizers for dye sensitized solar cells (DSSCs). These new push-pull sensitizers used a strong electron donor consisting of 3,4-ethylenedioxythiophene and two triphenylamine molecules connected together to form a TPA-EDOT-TPA (TET) motif, which is directly connected to tetra anchoring groups (A) without any π-spacers to construct A2-D-D-D-A2 architecture, three different anchoring series, viz. rhodanine-3-acetic acid (RA), cyanoacetic acid (CA), and 2-methyl quinoline-6-carboxylic acid (QA) were employed to investigate the influence of anchoring moieties on the electrochemical, thermodynamic, kinetics, and photovoltaic efficiency of DSSCs. The DSSCs devices showed a maximum overall power conversion efficiency (PCE) = 5.13%, short-circuit current density (JSC) = 12.71 mA.cm−2, open circuit voltage (VOC) = 0.62 V, and fill factor (FF) = 65.36% with a maximum incident photon conversion efficiency (IPCE) = 75% for TET(QA)4. The optical and electrochemical studies showed that TET(QC)4 achieved higher electron injection free energy (ΔG°inj) into CB edge of TiO2 as well as high recombination resistance (Rrec) compared to TET(RA)4, and TET(CA)4, which explains the outstanding charge separation and superior power conversion efficiency (PCE) of TET(QC)4 possessing quinoline-6-carboxylic acid (QC) anchoring group. Molecular modeling calculations using DFT and TD-DFT showed effective charge separation, where HOMO is delocalized over the donor scaffold (TPA-EDOT-TPA), and the LUMO is delocalized over only two anchoring groups on the same side of the donor system, which provides strong HOMO-LUMO overlap as well as intimate electronic coupling with TiO2 nanoparticle surface for electron injection. Further, the calculated values of the energy gaps (E0-0) and ground/excited stated oxidation potentials were in perfect agreement with the experimental results.

International audience; Cyclic voltammetry and spectroelectrochemistry (e.p.r.) were used to investigate the mechanisms implied in the electrocarboxylation of chloroacetonitrile (Cl-CH2-CN, noted RCl) mediated by [Ni(II)(terpy)2]2+. The oxidative addition of chloroacetonitrile on the electrogenerated [Ni(I)(terpy)]+ yields an alkyl-nickel R-Ni(III) complex which is reduced into an alkyl-nickel(II). E.p.r study shows that the homolytic nickel-carbon bond cleavage seems to be the more probable pathway to form the organic radical R-which is reduced to R−. Under carbon dioxide atmosphere, cyclic voltammetry studies show that CO2 was added on the alkyl-Ni(III) complex giving probably a CO2 adduct which is reduced to RCO2-Ni(II) complex allowing to release the carboxylate RCO2− and the active [Ni(I)(terpy)]+ complex. Controlled potential electrolyses showed that good carboxylated and faradic yields were obtained.

Aseries of previously unreported N-aryl-7-hydroxy-2-imino-2H-chromene-3-carboxamides were synthesized via the reaction of 2,4-dihydroxybenzaldehyde with cyanoacetic acid arylamides in the presence of a catalyst. The structures of the obtained compounds were confirmed by spectroscopic techniques. Biological tests showed that some of these compounds exhibited antimicrobial activity.

A new, efficient, and versatile one-pot cascade reaction of diverse Gewald’s aminothiophenes, 2-hydroxy-4-oxobut-2-enoic acid, and derivatives of cyanoacetic acid catalyzed by Et3N is presented. It enables direct synthesis of diverse 1-(2-oxoethylidene)-2-oxothieno[3,2-e]pyrrolo[1,2-a]pyrimidine in good to excellent yields. The reaction exhibits a broad substrate scope and also presents an opportunity for further modification of the structure. The method offers a convenient practical alternative to the known procedures. The synthesized thieno[3,2-e]pyrrolo[1,2-a]pyrimidine scaffold is an important structural motif of new poly(ADP-ribose) polymerase (PARP) inhibitors, playing a useful role in multiple pharmacological applications.

One of the important strategies for designing pure organic dyes is to improve the electron donating abilities of dye donors hence increase the intramolecular potential energy difference. In order to quantify the electron-donating capacity of organic units, we firstly propose a parameter donation ability (DA) value for evaluating the electron DA of organic units via theoretical calculation, by using of several fragments such as coplanar dithiophenyl pyrrole, triphenylamine (TPA), phenothiazine (PTZ) and cyanoacetic acid (CA) which is the research objects here. Inspired by the DA values of the above organic fragments, dye PSD-9, PSA-10 and PST-11 were designed and synthesized. Cyclic voltammetric (CV) measurements show that the DA values of dye PSA-10 and PST-11’s donor increases when TPA and PTZ groups are introduced into PSD-9, hence HOMO level increases and the band-gap narrow down. This change is reflected in the absorption spectra: the maximum absorption wavelength of PSA-10 and PST-11 is 63 and 84 nm red-shifted compared with PSD-9. Similarly, the molar extinction coefficients of PSA-10 and PST-11 are increased by 34.7 × 103 and 14.7 × 103 M−1 cm−1, respectively. Combining a mesoporous titania film grafted by these dithiophenyl pyrrole dye with iodine electrolyte, an 4.2% and 4.8% power conversion effciency (PCE) is achieved for PSA-10 and PST-11 at an irradiance of the AM1.5G sunlight, with an significant increasing compared to PSD-9 with an PCE of 1.6%. The typical photocurrent density–voltage (J–V) test shows that the short circuit current of dye PSA-10 and PST-11 is much higher than that of PSD-9, which is the main reason for the improvement of PCE. The red-shift and stronger IPCE curve is the most advantageous evidence of the change of short circuit current. Furthermore, electrochemical impedance measurements is studied for exploring the changes of open-circuit voltage of PSA-10 and PST-11, the results infer that larger donor units and long alkyl chains can effectively increasing current density on photoanode, hence increase the open circuit voltage of the devices.

3-Cyanopiperidin-2,6-diones are key intermediates in the synthesis of several drugs and natural products. We developed one-pot synthesis of 3-cyanopiperidin-2,6-diones by Knoevenagel condensation of cyanoacetic acid and aldehydes, followed by addition of cyanoacetic acid, Achmatowicz reaction and decarboxylation. We tested a wide range of aliphatic and aromatic aldehydes. Products were obtained under simple, environmentally friendly conditions and in yields up to 99%. Substrates were stirred in toluene at reflux, and filtered through short pad of silica gel, and the product was purified by recrystallization.

To study the various fundamental processes occurring inside the dye sensitized solar cell (DSSC), we have fabricated devices employing newly synthesized diphenylamine-based organic dyes with A-D-π-A configuration, carrying four different anchoring groups, namely, cyanoacetic acid (DDC), rhodanine acetic acid (DDR), 4-hydrazinylbenzoic acid (DDH), and barbituric acid (DDB), as effective sensitizers/cosensitizers. In the present work, all the bianchoring dyes were subjected to photophysical, electrochemical, thermodynamic, photoelectrochemical, and theoretical studies. All of them displayed characteristic λabs and λemi in the range of 415–480 and 570–680 nm, respectively. Their optical and electrochemical band gaps were calculated to be in the order of 2.1 to 2.3 eV. The calculated driving forces for electron injection (ΔGinj), recombination (ΔGinj), and regeneration (ΔGreg) processes were found to be negative, showing the feasibility of these processes, while their DFT studies clearly indicated the directi...

Donor–bridge–acceptor (D–π–A) compounds have garnered significant attention, and have led to increased efficiency of photovoltaic devices. In this study, an effective D–π–A dye (TPA-PT) was designed that contains tri-phenyl-amine, thiophene-pyrimidine and cyanoacetic acid as donor (D), π-bridge and acceptor (A), respectively. The TPA-PT was adsorbed on the semiconductor surfaces, i.e., Ti3O6H and Ti6O12H clusters, and light was shed on the adsorption behavior by bidentate bridging @Ti3O6H and chelating @Ti6O12H modes. The frontier molecular orbitals (FMOs) and structural and optical properties are studied by applying density functional theory (DFT) and time-dependent DFT (TD-DFT). Important parameters including charge transfer mechanism, electronic coupling constants (|VRP|), band alignment, electron injection (ΔGinject), relative electron injection (ΔGrinject) and light-harvesting efficiency are comprehensively investigated. The charge transfer from TPA-PT dye to the semiconductor surface of Ti3O6H and Ti6O12H clusters is explored as well. Additionally, the computed values of open-circuit photo-voltage (Voc) are presented for two cases of TiO2 and PCBM.

A safer, convenient, cost-effective, and scalable synthesis for 3,4-dicyanofuroxan (C4N4O2) is described. Dropwise treatment of a well-stirred suspension of cyanoacetic acid in dichloromethane with concentrated mixed acid (HNO3/H2SO4) affords dicyanofuroxan in 72% yield and in 84% purity after liquid chromatography analysis. Single crystal X-ray diffraction studies further confirm the product and yield its molecular conformation and crystal packing. During the dropwise addition of mixed acid, self-heating occurs, and this event is necessary for the reaction to adequately proceed. However, such self-heating is limited to the refluxing temperature of dichloromethane. This new method supersedes the previous methods used to synthesize dicyanofuroxan, which were low-yielding and of significantly lower purity, irreproducible, relied on expensive reagents, and suffered from dangerous exothermic profiles.

New dyes of the 3-[5-(4-alkyl-4H-thieno[3,2-b]indol-2-yl)thiophen-2-yl]-2-cyanoacrylic acid series were prepared based on 2-(thien-2-yl)-substituted thieno[3,2-b]indole by its sequential N-alkylation, formylation, and condensation of the resulting aldehydes with cyanoacetic acid. The possible application of these dyes as sensitizers of mesoporous titanium dioxide thin films in dye-sensitized solar cells (DSSC) was shown. It was established that the efficiency of DSSC based on the dye IS 4 is superior to that of a similar element based on the commercial dye N3 [cis-bis(isothiocyanato)bis(2,2′-bipyridyl-4,4′-dicarboxylato)ruthenium(ii)].

Novel phenyl-trisubstituted propyl 3-(R-phenyl)-2-cyanoacrylates (where R is 2,4,5-trimethyl, 2,4,6-trimethyl, 2,3-dimethyl-4-methoxy, 2,5-dimethyl-4-methoxy, 2,4-dimethoxy-3-methyl, 2,4-dimethoxy-6-methyl, 4-hydoxy-3,5-dimethyl, 2,3,4-trimethoxy, 2,4,5-trimethoxy, 2,4,6-trimethoxy, 3,4,5-trimethoxy) were prepared using piperidine-catalyzed condensation of substituted benzoic aldehydes and propyl ester of cyanoacetic acid with good yields (72–97 wt%). The ethenylbenzene copolymerization of cyanoacrylates (at 3/1 mol feed ratio) in solution with radical initiation at 70 °C resulted in formation of copolymers having MW 3.9 to 27.8 kD and 8.4–25.8 mol% of cyanoacrylate. FTIR, 1H and 13C NMR were used to analyze the structure. Thermal behavior of the copolymers was analyzed by DSC, Tg (81–129 °C) and TGA. Decomposition of the copolymers in nitrogen occurred in two steps, first in the 200–500 °C range with residue (0.5–7.3 wt%)and then in the 500–800 °C range.

Density functional theory and time-dependent approaches are applied for theoretical investigation of a new class of novel carbazole-based d–D–π–A-type dyes, where the carbazole moiety is the main electron donor, bithiophene behaves as a π-bridge, and cyanoacetic acid as an electron acceptor for all the studied dyes, whereas the terminal electron donor unit is varied to thiophene, thienothiophene, carbazole, dimethoxyphenyl, and indole. The influence of the terminal electron donor on the optoelectronics properties is investigated for the dyes in isolated state and in chloroform solvent. Their absorption spectra and electronic and structural properties are evaluated and discussed. The theoretical results show that all the dyes exhibit excellent optoelectronic properties. In particular, D5 with indole as the terminal electron donor moiety has potential for use as a sensitizer for nanocrystalline TiO2 solar cells based on its red-shifted absorption spectrum, reduced energy gap, lowest λtotal value, and higher $$\Delta G^{\text{Inject}}$$ and $$\Delta G^{\text{Reg}}$$ values.

In this work, a series of eight metal-free organic dyes based on triphenylamine as a donor and cyanoacetic acid as an acceptor of electrons with the donor-π-acceptor structure were studied by DFT and TD-DFT methods. Their electronic properties, absorption spectra, and molecular nonlinear optical (NLO) responses have been analyzed and reported. The influence of the change of π-conjugated linker on the electrochemical and photophysical properties of these metal-free organic dyes has been investigated and discussed in detail. The energy gap decreases by going from L1 to L8, which causes a large NLO response for the studied dyes. The natural bond orbital (NBO) analysis reveals that the separation of charge occurred upon photoexcitation and the electrons moved from the donor to the acceptor moiety. A high NLO response reveals that this kind of metal-free organic dyes has eye-catching and remarkably large first hyperpolarizability βtot values, especially for L7 ((E)-2-cyano-3-(3-((E)-2-(3-((E)-4-(diphenylamino)styryl)benzo[c]thiophen-1-yl)vinyl)benzo [c]thiophen-1-yl)acrylic acid) and L8 ((E)-2-cyano-3-(7-((E)-2-(7-((E)-4-(diphenylamino)styryl)thieno[3,4-b]pyrazin-5-yl)vinyl)thieno[3,4-b]pyrazin-5-yl)acrylic acid) with 150423.50 (a.u) and 202773.63 (a.u), respectively. Our research has been carried out to extend the conjugation of organic materials by controlling their π-conjugated linker to design new appealing NLO compounds. This study shows that these dyes are promising and have special properties for modern hi-tech applications such as solar cells, transistors, and organic light-emitting diodes (OLEDs), and even these properties can be adjusted and enhanced by the incorporation of the benzothiophene or thienopyrazine derivatives as a bridge so as to improve from L7 to L8.

Herein, we report design, synthesis and photovoltaic performance of four novel metal-free heteroaromatic photosensitizers coded IA 1-4 with (D-D)2-D-A architecture carrying electron donating triphenylamine coupled with EDOT core which is directly connected to four different electron withdrawing/anchoring groups, viz. rhodamine-3-acetic acid, cyano acetic acid, 2-methyl quinoline-6-carboxylic acid and 1-phenyl-pyrazol-5-one-3-carboxylic acid without any π-spacer. The newly designed IA 1-4 were applied as sensitizers and co-sensitizers in DSSCs. Their structures were confirmed by FT-IR, 1H NMR, MS and elemental analyses. The photosensitizers were subjected to optical and electrochemical studies in order to investigate their absorption/emission behavior as well as HOMO/LUMO energies. The UV–Vis revealed that IA 1-4 exhibited at 464, 497, 531 and 412 nm,λmax respectively. Their optical band gap is in the range of 1.95–2.28 eV. From the energy level diagram of the named photosensitizer, it is clear that all the dyes have good thermodynamically favorable ground and excited state oxidation potentials for electron injection into CB edge of TiO2 as well as dye regeneration. The photovoltaic performance studies indicate that, dye IA-1 anchored with cyanoacetic acid displayed the highest IPCE (61.5%), resulting in PCE of 5.92% (JSC = 12.3 mA cm−2, VOC = 0.68 V, FF = 70.29%). Furthermore, when IA-1 was used as a co-sensitizer with MH-13, a total PCE of 8.43% (JSC = 22.8 mA cm−2, VOC = 0.66 V, FF = 54.1%) was achieved to gain more insights into the equilibrium molecular geometry (EMG), thermodynamic parameters and vertical electronic excitation, DFT studies were performed using GAUSSIAN 09 software to calculate the EMG of each photosensitizer, its and electron cloud delocalization of HOMO/LUMO levels and vertical electronic excitation. Results from FMO revealed that dyes IA 1-4 showed effective charge separation, which translated into greater ICT behavior with IA-1 being the highest in photovoltaic performance.

Three novel D−π−A type dyes DC1∼3, which consisting of indolo[2,3-a]carbazole as donor scaffold linked to the acceptor/anchoring unit cyanoacetic acid via different π-spacers, were successfully designed and synthesized. The structure, photophysical and electrochemical properties, and photovoltaic properties of the three sensitizers were investigated in detail. The results indicate that the donor 11,12-bis(2-ethylhexyl)-11,12-dihydroindolo[2,3-a]carbazole with two branched alkyl chains is effective in inhibiting the intermolecular π−π aggregation effects, and the auxiliary alkyl chains in the π-bridge cause the DC3-based DSSCs to exhibit higher open circuit voltages than that of the devices based on dye DC2. Among all of the devices fabricated with the dyes, the DC3-based cells without chenodeoxycholic acid (CDCA) exhibit the best photovoltaic performance, with a short-circuit current density of 10.98 mA cm−2, an open circuit voltage of 752 mV and a fill factor of 0.725, corresponding to a highest power conversion efficiency of 5.98% in liquid electrolyte.

Chiral aziridines are structure units found in many biologically active compounds and are important building blocks in organic synthesis. Herein, by merging nucleophilic generation through copper(I)-catalyzed decarboxylation and activation of poorly electrophilic 2H-azirines through protonation with carboxylic acids, an asymmetric decarboxylative Mannich reaction between α,α-disubstituted cyanoacetic acids and 2H-azirines is uncovered, which leads to generation of chiral aziridines containing vicinal tetrasubstituted and acyclic quaternary stereogenic carbon centers in good to excellent diastereo- and enantioselectivities. At last, transformations of the produced chiral aziridine are successfully carried out to deliver synthetically useful compounds., Due to their poor electrophilicity, 2H-azirines do not easily react with nucleophiles. Here, the authors show an acidic activation of 2H-azirines by cyanoacetic acid coupling partners affording chiral aziridines containing vicinal tetrasubstituted and acyclic quaternary stereogenic carbon centers.

Herein we present a laboratory rotational study of cyanoacetic acid (CH2(CN)C(O)OH), an organic acid as well as a -CN bearing molecule, that is a candidate molecular system to be detected in the interstellar medium (ISM). Our investigation aims to provide direct experimental frequencies of cyanoacetic acid to guide its eventual astronomical search in low-frequency surveys. Using different jet-cooled rotational spectroscopic techniques in the time domain, we have determined a precise set of the relevant rotational spectroscopic constants, including the 14N nuclear quadrupole coupling constants for the two distinct structures, cis- and gauche- cyanoacetic acid. We believe this work will potentially allow the detection of cyanoacetic acid in the interstellar medium, whose rotational features have remained unknown until now., The authors thank the financial funding from Ministerio de Ciencia e Innovación (CTQ2016-76393-P and PID2019-111396GB-I00), Junta de Castilla y Leon (VA077U16 and VA244P20), and European Research Council under the European Union's Seventh Framework Programme (FP/2007-2013)/ERC-2013-SyG, grant agreement No. 610256 NANOCOSMOS. E.R.A. thanks Ministerio de Ciencia, Innovacion y Universidades for Juan de la Cierva grant (FJC2018-037320-I). M.S.N. acknowledges funding from the Spanish "Ministerio de Ciencia, Innovacion y Universidades" under predoctoral FPU Grant (FPU17/02987).

A nickel-catalyzed reductive cross-coupling of redox-active N-hydroxyphthalimide (NHP) esters and iodoarenes for the synthesis of α-aryl nitriles is described. The NHP ester substrate is derived from cyanoacetic acid, which allows for a modular synthesis of substituted α-aryl nitriles, an important scaffold in pharmaceutical sciences. Mechanistic studies reveal that decarboxylation of the NHP ester to the reactive radical intermediate is accomplished by a combination of a chlorosilane additive and Zn dust. The reaction exhibits a broad scope as many functional groups are compatible under the reaction conditions, including complex highly functionalized medicinal agents.

Two different copper and gallium arylcorroles have been functionalized using the Vilsmeier-Haack reaction. A further Knoevenagel reaction with cyanoacetic acid was performed on both complexes, affording the desired products with yields above 90 %. The newly synthesized compounds have been thoroughly characterized by a combination of spectroscopic methods, optical analyses, and X-ray crystallography. Moreover, they have been tested as anchoring groups for the hydrothermal synthesis of ZnO nanoparticles. The morphology of the heterogeneous composites has been studied by SEM, EDS and fluorescence microscopy analyses, thus confirming the presence of the corrole macrocycle in the hybrid material.

A bio-inspired family of organic dyes with bichromic-bipodal architectures were synthesized and tested in dye-sensitized solar cells (DSSC). These dyes are comprised of a D-&pi, D-A motif with two triphenylamine (TPA) units acting as donors (D) and two cyanoacetic acid acceptors (A) capable of binding to a titania semiconductor. The role of the thiophene &pi, spacer bridging the two TPA units was examined and the distal TPA (relative to TiO2) was modified with various substituents (-H, -OMe, -SMe, -OHex, -3-thienyl) and contrasted against benchmark L1. It was found that the two TPA donor units could be tuned independently, where &pi, spacers can tune the proximal TPA and R-substituents can tune the distal TPA. The highest performing DSSCs were those with -SMe, 3-thienyl, and -H substituents, and those with one spacer or no spacers. The donating abilities of R-substituents was important, but their interactions with the electrolyte was more significant in producing high performing DSSCs. The introduction of one &pi, spacer provided favourable electronic communication within the dye, but more than one was not advantageous.

Two new carboxylated 1,3-indanedione sensitizers (MPhe-ind and BPhe-ind) were synthesized and their dye-sensitized solar cells (DSSC) performance were compared with the corresponding standard cyanoacetic acid sensitizers (MPhe-cn and BPhe-cn). The carboxylated 1,3-indanedione sensitizers have shown almost 100 nm enhanced absorption curves compared to the cyanoacetic acid dyes with an extended IPCE curve up to 800 nm. Despite greater absorption and electrochemical properties, the synthesized dyes showed moderate efficiencies (2.10% and 2.67%) than standard dyes. The low electron injection efficiency and recombination of carboxylated 1,3-indanedione might be responsible for low efficiency. Detailed investigation studies have been performed and complemented with the theoretical studies.

Theoretical study of the use of cyano acid derivatives as electron acceptor groups in cyanidine as dye compounds of dye sensitized solar cells (DSSC) has been carried out based on energy parameters of HOMO-LUMO, LUMO electron localization, spectra, light absorption efficiency, coupling constants, and sensitizer bond length with TiO2. This study aims to determine the effect of cyanoacetic acid, cyanoacrylic benzothiadizole, cyanovinyl acid and cyanosynamic acid as electron acceptors on the photoelectric characteristics of cyanidine and determine the cyanoic acid derivative which can produce cyanidine photoelectric characteristics better based on energy parameters HOMO-LUMO, LUMO electron localization, spectra, light harvesting efficiency, coupling constant (VRP), and bond length of sensitizer with TiO2. This research begun with molecular optimization using DFT and TDDFT method with basis set of 6.311G *. HOMO-LUMO parameters used the same method with analysis technique using ECCE. The LUMO electron localization parameters use the same method, but the analysis technique used ECCE. Spectra using DFT method, using analytical technique using Chemcraft. Parameters of light absorption efficiency using DFT and TDDFT method with calculation technique using existing equations. Coupling constant parameters using the same method, the calculation technique used the energy equation of dye compounds were calculated in the conditions of HOMO, LUMO and TiO2 energy. Parameter length of the sensitizer bond with TiO2 were calculated used DFT method with avogadro analysis technique. Cyanidin cyanoacetate became the best modification based on HOMO LUMO energy parameter -4.569 and -1.01 eV, respesctively. In the electron localization parameter, the best modification was produced in cyanidine cyanoacetate with an electron-centered pattern on the cyanoacetic group. Spectra parameters produced the best modification, cyanoacetic cyanidine with a wavelength of 378.811 nm with osillator strength of 0.633. The light absorption efficiency parameters resulted in the best modification of cyanidin cyanoacetate with a value of 0.767. For parameter of clutch constant, best modification is cyanidin benzothiadizol sianoakrilik with a value -0.269. The best modification on the parameter length of the sensitizer bond with TiO2 was cyanidine cyanoacetate with a bond length of 1.926 Å.

Herein, we report the design and synthesis of two metal-free organic sensitizers (MR-5 & MR-6) with a D-π-A-π-A architecture based on a trimethoxy benzene donor core carrying two different withdrawing/anchoring groups including cyanoacetic acid and rhodanine-3-acetic acid via thiophene as a π-spacer. Benzothiadiazole was incorporated as a strong auxiliary electron acceptor, which greatly improved the molar extinction coefficient and electronic coupling across the molecular diameter of the dyes. The optical and electrochemical properties of the two dyes were investigated. The photovoltaic studies revealed that MR-5 anchored with cyanoacetic acid showed significantly greater light harvesting (IPCE), which resulted in improved PCE with better photovoltaic parameters than MR-6. MR-5 achieved the higher total solar-to-electric conversion efficiency of 6.03% and showed an IPCE of 65% at 420 nm. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were used to study equilibrium molecular geometries, frontier molecular orbitals, vertical electronic excitations, and the theoretical data were consistent with experimental results.

A series of 1,5-bis(4-aryl/heteryl)-3-cyanoformazan derivatives was synthesized and characterized by spectral analysis. The synthesis strategy involved an easy and practical diazo coupling of different aryl (heteryl) diazonium salts with cyanoacetic acid. The synthesized compounds were electrostatically conjugated to gold and/or silver nanoparticles in dimethylsulfoxide and were examined as photosensitizers for photodynamic therapy (PDT). The PDT activity of the formazan derivatives alone and conjugated with metal nanoparticles was investigated against HL-60 cells under dark and light conditions. Formazan derivatives and their conjugates showed variable promising anticancer activity in dark and light conditions related to their structures. The interaction of synthesized formazan derivatives with metal nanoparticles enhanced the light absorption of the dyes and thus showed remarkable increase in PDT against cancer cells.