Cyanide Research Articles

Cyano and Fluorine-Enhanced Copolymer Electrolytes: Synergistically Boosting High-Voltage Lithium Metal Batteries.

In high-voltage lithium metal batteries, designing electrolytes with low salt concentrations to achieve stable electrode interfaces presents a formidable challenge. High-concentration electrolytes stabilize the interface through an anion-derived LiF-rich interphase; however, their anion-rich solvation structures compromise the ionic conductivity. This study introduces a polymer-derived interphase that maintains interface stability at low lithium salt concentrations (∼1 M). This strategy enables copolymer electrolytes to sustain the Li|Li cell for over 2500 h at 0.1 mA/cm2, even with a water content of 1000 ppm. Moreover, this research addresses the weak solvation effects in fluorinated polymer electrolytes by modulating the strongly solvating cyano groups, resulting in electrolytes with a high ionic conductivity of 4 × 10-5 S/cm at 30 °C. A 143.8 Wh/kg Li|LiNi0.8Co0.1Mn0.1O2 pouch cell, with a lean electrolyte ratio of 5 g/Ah and a low negative/positive capacity ratio of 4, maintains a capacity retention of 90.5% after 29 cycles.

Electrochemically Stable and Ultrathin Polymer-Based Solid Electrolytes for Dendrite-Free All-Solid-State Lithium-Metal Batteries

Abstract Polymer-based composite solid electrolytes (PCSEs) are increasingly studied in all-solid-state lithium-metal batteries (ASSLMBs) due to the combined advantages of better flexibility of polymer and higher ion conductivity of ceramic electrolytes. However, most reported PCSEs are overly thick, increasing internal resistances. Besides, the poor stability at the Li metal-electrolyte interfaces often leads to severe lithium dendrite formation and reduced cycling stability. Here, we fabricate an ultrathin PCSE with a thickness of 12.4 μm, incorporating polyacrylonitrile (PAN) nanofibers as the structural matrix, and a filler with polyethylene oxide and Li6.5La3Zr1.5Ta0.5O12 (LLZTO). Due to the formation of the LiCN layer on the surface of the lithium metal and the Li-ion transport pathways induced by the dehydrocyanation reaction at the LLZTO/PAN interfaces, the PCSE exhibits a high critical current density of 1.8 mA cm-2 and a low energy barrier of 0.278 eV for Li-ion transfer, accommodating the fast Li-ion migration to avoid Li-dendrite growth. In addition, the stable nitrile groups and the dehydrocyanation reaction ensure the electrochemical stability of the PCSE with a high oxidation voltage of 5.5 V and an exceptional cycling stability (2100 h) in Li||PCSE||Li symmetric cells. Additionally, the Li||PCSE||LiFePO4 full cells demonstrate a high volumetric energy density of 338.3 Wh L-1 at 0.1 C and a robust stability over 100 cycles at 0.5 C. The study offers a new approach for fabricating ultrathin PCSEs and provides insights into the mechanisms of dendrite-free formation, guiding the development of high-performance PCSEs for ASSLMBs.

Photochemical and Collision-Induced Cross-Linking of Lys, Arg, and His to Nitrile Imines in Peptide Conjugate Ions in the Gas Phase.

We report a study of internal covalent cross-linking with photolytically generated diarylnitrile imines of N-terminal arginine, lysine, and histidine residues in peptide conjugates. Conjugates in which a 4-(2-phenyltetrazol-5-yl)benzoyl group was attached to C-terminal lysine, that we call RAAA-tet-K, KAAA-tet-K, and HAAA-tet-K, were ionized by electrospray and subjected to UV photodissociation (UVPD) at 213 nm. UVPD triggered loss of N2 and proceeded by covalent cross-linking to nitrile imine intermediates that involved the side chains of N-terminal arginine, lysine, and histidine, as well as the peptide amide groups. Cross-linking yields were determined from UVPD-MS2 measurements as 67%, 66%, and 84% for RAAA-tet-K, KAAA-tet-K, and HAAA-tet-K ions, respectively. CID-MS3 of the denitrogenated ion intermediates from RAAA-tet-K, KAAA-tet-K, and HAAA-tet-K indicated overall cross-linking yields of 80%, 89%, and 80%, respectively. The nature of the cross-linking reactions and cross-link structures were investigated for RAAA-tet-K by high-resolution cyclic ion mobility mass spectrometry that identified precursor ion conformers and multiple dissociation products. All sequences were subjected to conformational analysis by Born-Oppenheimer molecular dynamics, and energy analysis by density functional theory calculations with M06-2X/def2qzvpp that provided relative and dissociation energies for several cross-link structural types. The cross-linking reactions were substantially exothermic, driving the efficient conversion of nitrile-imine intermediates to cyclic products. The principal steps in covalent cross-linking involved proton transfer onto the nitrile imine group accompanied by nucleophilic attack by the peptide side-chain and amide groups. Blocking the proton transfer and nucleophile resulted in a loss of cross-linking abilities.

Catalytic Reductive Amination and Tandem Amination-Alkylation of Esters Enabled by a Cationic Iridium Complex.

Reported herein is a convenient and efficient method for one-pot, catalytic reductive amination, as well as the first multi-component tandem reductive amination - functionalization of bench-stable and readily available common carboxylic esters. This method is based on the cationic [Ir(COD)2]BArF-catalyzed chemoselective hydrosilylation of esters, followed by one-pot acid-mediated amination and nucleophilic addition. The reaction was conducted under mild conditions at a very low catalyst loading (0.1 mol% of Ir), which could be further reduced to 0.001 mol%, as demonstrated by a reaction at a 15 g scale. The method is highly versatile, allowing the use of esters with or without α-protons for the N-mono-alkylation of primary and secondary amines to produce diverse secondary and tertiary amines, as well as α-branched/functionalized amines. The method is highly chemoselective and tolerates a variety of functional groups such as bromo, trifluoromethyl, ester, and cyano groups. The value of the method was demonstrated by the one-step catalytic synthesis of two bio-relevant N-mono-methyl α-amino esters and the antiparkinsonian agent piribedil, as well as by the use oftwo shorter chain triglycerides as alkylating feedstock.

Structure-activity relationships between nitrile analogues and acaricidal activities against Haemaphysalis longicornis.

A recent increase in severe fever with thrombocytopaenia syndrome (SFTS) virus cases in Korea has been observed. This virus attacks humans and animals, and no drug is available for its treatment. This study is investigating potential control measures targeting the causative agent, Haemaphysalis longicornis. Lepidium meyenii oil was ≈8.3-, 4.2- and 4.1-fold more active than diethyltoluamide against H. longicornis larvae, nymphs and adults, respectively. The major components of L. meyenii oil were identified as benzyl nitrile (71.64%), followed by ethyl linoleic acid (13.32%), ethyl palmitate (7.81%) and 3-methoxybenzyl nitrile (2.10%). In testing individual components of the oil were tested against H. longicornis adults, the half-maximal lethal dose (LD50) values for benzaldehyde, benzyl nitrile and benzyl isothiocyanate were found to be 9.21, 9.19 and 18.26 μg cm-3, respectively. The acaricidal component was isolated and identified as benzyl nitrile. To establish the structure-activity relationships between nitrile analogues and acaricidal activities, benzyl nitrile (LD50: 0.56, 6.38 and 9.19 μg cm-3) exhibited the highest acaricidal activities against H. longicornis larvae, nymphs and adults, followed by benzoyl nitrile (3.24, 8.36 and 15.47 μg cm-3), phenyl nitrile (5.45, 9.35 and 17.48 μg cm-3) and diethyltoluamide (7.95, 14.81 and 22.12 μg cm-3). However, the presence of allyl, methyl or vinyl functional groups bound to the nitrile group abolished the acaricidal activity. These results demonstrate that L. meyenii oil, benzyl nitrile, benzoyl nitrile and phenyl nitrile represent suitable options for the secure management of H. longicornis. Nevertheless, additional research is essential to develop formulations that enhance the efficacy and safety of the aforementioned acaricides. © 2024 Society of Chemical Industry.

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina.

A new psammaplysin derivative, ceratinadin G (1), was obtained from the Okinawan marine sponge Pseudoceratina sp., and the gross structure was clarified through spectroscopic and spectrometric analyses. The absolute configuration of compound 1 was established by comparing its NMR and ECD data with those of the known psammaplysin derivative, psammaplysin F (2). Ceratinadin G (1) is a rare nitrile containing a cyano group as aminoacetonitrile, and is the first psammaplysin derivative possessing a cyano group. In vitro assays indicated that compound 1 displayed moderate cytotoxicity against L1210 murine leukemia cells and KB epidermoid carcinoma cells.

Conjugated phthalocyanine-based framework as artificial SEI for over 400 Wh kg−1 lithium metal battery

Abstract High-voltage lithium metal batteries (HVLMB) are appealing candidates for next-generation high-energy rechargeable batteries, but practical applications are still limited by the severe capacity degradation, attributed to the poor interfacial stability and compatibility between the electrode and electrolyte. In this work, a two-dimensional conjugated phthalocyanine framework containing single cobalt atoms (CoSAs-CPF) is developed as a novel artificial solid electrolyte interphase (SEI), where a large amount of charge is transferred to the CPF skeleton due to the Lewis acid activity of the Co metal sites and the strong electron-absorbing property of the cyano group (−CN), greatly enhancing the adsorption of Li+ and regulating Li+ distribution toward dendrite-free Li-metal batteries, superior to most of the reported SEI membrane. As a result, the Li||Li symmetrical cell with CoSAs-CPF modified Li-anodes (CoSAs-CPF@Li) exhibits a low polarization with an area capacity of 1.0 mAh cm−2 over 3500 h. The LiFePO4||CoSAs-CPF@Li (LFP: 20 mg cm−2) delivers an ultra-long cycling life up to 1000 cycles with a high-capacity retention of 98.6%. Remarkably, the high-voltage LiNi0.8Co0.1Mn0.1O2||Li@CoSAs-CPF (NCM811: 10 mg cm−2) demonstrates a long cycling life over 800 cycles with a high-capacity retention of 80%. Meanwhile, in-situ ultrasonic transmission technology confirms the admirable ability of artificial CoSAs-CPF SEI to stabilize the Li-anode interface in pouch cells during cycling. Remarkably, the NCM811||Li@CoSAs-CPF pouch cell exhibits an energy density of 421 Wh kg−1 and keeps 130 cycles with a low electrolyte/capacity ratio of 2.5 g Ah−1. The strategy of constructing CoSAs-CPF-reinforced Li-anode provides a promising direction for high-energy-density HVLMB with long-cycling stability.

Recasting the wobbling-in-a-cone model for the rotational anisotropy of phenylselenocyanate in poly(methyl methacrylate): Effect of internal bond rotation and polymer segmental motion.

The rotational anisotropy of a molecule in a constrained environment is modeled by wobbling-in-a-cone (WIAC) motion, which describes the angular space sampled by the molecule. Recent polarization-selective IR pump-probe measurements have applied this model to phenylselenocyanate in amorphous polymers, aiming to probe the surrounding free volume. A faster rotational timescale was hypothesized to reflect the angular space within the static voids of the polymer matrix, while a slower timescale relates to constraint release by the polymer backbones. To better quantify the contributions of internal bond rotation and polymer segmental motion, we conduct molecular dynamics simulations on two phenylselenocyanate variants with different internal rotational barriers, as well as on p-chlorobenzonitrile, which lacks such internal rotational freedom, within a polymer matrix. Our analyses reveal that the faster (∼10ps) component of the cyano group's anisotropy decay arises from concurrent angular sampling due to internal bond rotation and WIAC motion. Conversely, polymer segmental motion was found to have a minimal influence on the slow (∼200ps) anisotropy component. Based on these findings, we refine the WIAC model to better link rotational diffusion with the distinct free volume elements accessed by the probe molecule. This revised model allows the quantification of free volume elements associated with both internal bond rotation and wobbling motion within the polymer cage.

Three‐Component Alkylsulfonylation of 1‐Acryloyl‐2‐cyanoindoles with Hantzsch Esters through Sulfur Dioxide Insertion

A three‐component alkylsulfonylation/cyclization/ hydrolysis relay reaction of 1‐acryloyl‐2‐cyanoindoles with 4‐alkyl Hantzsch esters and Na2S2O5 to access a series of alkylsulfonyl pyrrolo[1,2‐a]indolediones derivatives involving in situ sulfur dioxide insertion is established. With this method, a variety of primary and secondary alkyl radicals can be used for trapping sulfur dioxide and in situ formed corresponding alkylsulfonyl radical intermediates, followed by alkyl sulfonyl radical addition, cyclization and hydrolysis. In addition, this reaction goes through once selective cleavage of σ carbon‐carbon bond and following successively formation of three new chemical bonds, in which cyano group acts as the dual roles, including the radical acceptor and carbonyl source.

Guidance on surface cyclization reactions through coordination structures.

Metal coordination structures, formed through interactions between metal atoms and active functional groups, are crucial in determining the reaction pathway and its products. This study examines 2,3-dibromo-6,7-dicyanonaphthalene (DDN), which contains cyano and halogen groups, deposited on Au(111) and Ag(111) surfaces, using scanning tunneling microscopy at room temperature. The reason for the formation of various cyclization products on the Au(111) surface is that the bromine of DDN and the cyano group have overlapping reaction temperature ranges. This overlap leads to the coexistence of C-C coupling products from the debromination sites and cyclization products from the cyano groups. In contrast, on the Ag(111) surface, the final cyclization reaction produces a single type of polymer directly induced by the metal-coordinated structures. The synergistic effects between coordination structures and the activation temperatures of molecular reaction groups are crucial factors in regulating polymerization reactions.

Dual Photoredox/Copper-Catalyzed Three-Component Alkylcyanation of Alkenes and 1,4-Alkylcyanation of 1,3-Enynes Employing Sulfoxonium Ylides as the Carbon Radical Precursors.

A novel dual photoredox/copper-catalyzed three-component alkylcyanation of alkenes and 1,4-alkylcyanation of 1,3-enynes have been developed. In this radical cyanoalkylation reaction, the photoredox induced alkyl radical from sulfoxonium ylides adds to the carbon-carbon double bonds of styrenes or 1,3-enynes, and the generated benzylic or allenyl radicals couple with a Cu(II) cyanide complex to achieve selective cyanation. The reaction exhibits high chemo- and regioselectivity and a wide substrate scope, providing an efficient method for the synthesis of alkyl nitriles and allenyl nitriles in a single step.

Inverse Electron Demand Diels-Alder Reaction of Pyrazines with 2,5-Norbornadiene as Acetylene Precursor

Herein, we report the reaction of pyrazines with 2,5-norbornadiene, an acetylene precursor, as a cascade of Diels-Alder reactions yielding substituted pyridines. In contrast to the known examples of intermolecular Diels-Alder type reaction of pyrazines with acetylene, which usually leads to a mixture of products, in our case the formation of a single isomer was observed. The proposed approach allows the conversion of pyrazines with different types of substitution, except those containing methyl and amino donor groups, to pyridines. In addition, highly functionalized aminonicotic esters were obtained, which can be used for the synthesis of bioactive compounds. An unusual course of the Diels-Alder reaction was found in the case of tetrasubstituted pyrazines, which cleave organic nitriles instead of HCN. Quantum-chemical modeling of possible transition states showed that this Diels-Alder reaction proceeds via cycloaddition of 2,5-norbornadiene to pyrazine with sequential elimination of HCN and cyclopentadene; the reaction pathway including initial formation of acetylene from norbornadiene and subsequent Diels-Alder reaction with the acetylene was rejected as kinetically unfavorable.

Pseudohalogen regulation of benzimidazole small molecule acceptor to optimize molecular crystallinity in Q-PHJ organic solar cells

The cyano group is a pseudohalogen with chemical properties similar to halogens. It has the ability to regulate the stacking and energy levels of molecules in organic solar small molecule non-fullerene acceptor materials. In this study, we introduce two novel alkylated derivatives, BMIC-CN-Me and BMIC-CN-iPr, featuring a cyano-modified benzimidazole core. This central nucleus design is reported for the first time, offering a unique approach to molecular engineering in organic photovoltaics. BMIC-CN-Me, in particular, enhances device performance by meticulously managing molecular stacking through steric hindrance. Analysis via single-crystal X-ray diffraction reveals five distinct stacking modes, with an average intermolecular distance of approximately 3.31 Å, optimizing the efficiency of charge transfer. This precise molecular arrangement elevates the photoconversion efficiency (PCE) of the non-fullerene acceptor, based on the benzimidazole core, to an impressive 17.6 %. Moreover, the material demonstrates exceptional stability, retaining over 80 % of its initial efficiency after 1200 h in a glove box and maintaining more than 80 % of its original efficiency after 500 h of continuous simulated solar irradiation. Compared to the 2-methylimidazole-derived molecules acceptor, devices prepared using BMIC-CN-Me demonstrate superior performance due to their better-matched energy levels and UV–Vis absorption spectrum. Furthermore, when contrasted with BMIC-CN-iPr, BMIC-CN-Me exhibits a more tightly packed molecular arrangement. These factors contribute to more effective exciton dissociation, accelerated charge transport, and the suppression of recombination, leading to an enhanced fill factor and overall photoelectric conversion efficiency. The quasi-planar heterojunction architecture further bolsters device stability. The cyano-modified benzimidazole structure provides additional non-covalent interaction sites, which augment the material’s stability. Our findings indicate that the cyano substitution of the benzimidazole core not only enhances material stability and molecular aggregation but also significantly improves the performance of organic solar cells. This innovative approach to molecular design holds promise for the development of high-performing and durable organic photovoltaic materials.

Comprehensive insight into the interfacial adsorption mechanism of pyridine derivatives by molecular dynamics simulations, GFN-xTB and first-principles calculations

The application of computational chemistry methods is becoming increasingly prosperous in the interfacial adsorption study of corrosion inhibitors. In this work, three typical computational chemistry methods, molecular dynamics (MD) simulations, GFN-xTB and first-principles calculations, were employed to investigate the interfacial adsorption processes of four pyridine derivatives (CP, ACP, DPA and ABOP) on Fe surface. With related to the measured corrosion inhibition efficiencies of the four pyridine derivatives for mild steel in HCl solution by weight loss and electrochemical tests, the calculated results by these three methods were compared in terms of the adsorption configurations, bonding mode, and the adsorption strength (adsorption energy). Based on the radical distribution function (RDF) from MD simulations, it is only roughly inferred that pyridine derivatives can chemically adsorb on Fe surface. While both GFN-xTB and first-principles calculations indicate that the adsorptions of the four pyridine derivatives are through the N and unsaturated C atoms. In particular, compared to DPA and ABOP molecules, the cyano groups (−CN) of CP and ACP molecules exhibit outstanding adsorption capacity, which endow CP and ACP with better inhibition performances.

Wave-transparent and eco-friendly flame-retardant phosphorus-based phthalonitrile/quartz composites by a synchronized self-curing strategy with cyano and alkynyl groups

The robust human–machine interaction systems of the aerospace industry necessitate the development of thermal resistant wave-transparent composites, with a pivotal focus on organic resin matrix. However, enhancing the heat resistance of such materials while preserving other critical attributes has been a formidable challenge. In this study, a novel designed strategy of a dual-curing functional phosphorus-based phthalonitrile monomer (P-ALK-PN) has been proposed. The optimized curing temperatures for intra- or intermolecular Diels-Alder reactions of alkynyl groups and polyaddition reaction of cyano groups resulted in a homogeneous and highly crosslinked N-enriched phthalonitrile system. After curing at 450 °C, the resin, namely P-ALK-PN-450 °C, demonstrated exceptional thermal stability (T5% = 644 °C), thermo-oxidative stability (T5% = 554 °C), and char yield at 800 °C (90.7 % in N2 and 67.5 % in air). Their quartz fiber reinforced composites (P-ALK-PN/QFs) were subsequently fabricated by the hot-pressing process. Upon post-curing at 420 °C, P-ALK-PN-420 °C/QF displayed elevated glass transition temperature (550 °C), flexural strength (319 MPa), and relatively low dielectric properties with a dielectric constant (Dk) of approximately 4.2 and a dissipation factor (Df) less than 0.02 across a wide temperature ranging from 25 °C to 600 °C. Especially, it exhibited excellent flame retardancy (only a 6.7 % weight loss at ambient temperatures exceeding 1300 °C for 200 s) as well, stemming from release of eco-friendly inert gases (NH3) and formation of a graphitized protective layer during pyrolysis. These promising results highlight the potential applications of P-ALK-PN resins in aerospace and high-performance engineering fields.

Improved property of block copolymer-based anion exchange membranes by attaching multi-ion flexible strings

To meet high conductivity and sufficient anti-swelling of anion exchange membranes (AEMs), a collaborative strategy of combining multi-ion flexible string and block backbone is adopted to construct membrane’s architecture. Then a series of adamantane-contained poly(arylether ketone nitrile)s block copolymers has been synthesized and grafted with multi-ion flexible strings to form hydrophilic domains. In addition, the hydrophobic segments with nitrile groups are aimed to enhance the entanglement between chains and limit swelling degrees of membranes. Along the steps, clear phase separation morphologies are formed for creating efficient ionic channels. The resulted AEMs exhibit improved conductivity and dimensional stability at low hydration levels, e.g. conductivity of 91.7−119.4 mS cm-1, swelling ratio (SR) of 14.4%−19.5%, water uptake (WU) of 38.3%−57.9% and λ values of 13.4−15.7 at 80 °C. Furthermore, the AEMs prepared exhibit excellent mechanical properties and good thermal stability below 180 °C. However, further optimization is required for a better alkaline stability.

Facile access to spirobifluorene-fused chiral multi-resonance materials with ultra-narrowband blue emission

Narrowband multiple resonance (MR) emitters with circularly polarized luminescence (CPL) hold significant promise for three dimension organic light-emitting diode (3D-OLED) displays. In this work, we present a simple method for developing a new type of 9,9’-spirobifluorene-based CP-MR emitters by a recrystallization resolution technology and chlorine (Cl)-directed electrophilic borylation reaction, both of which significantly enhances the efficiency and scalability for mass production. This approach allows for integrating an asymmetric 9,9’-spirobifluorene core between two MR frameworks to achieve optically active CP-MR emitters. The highly rigid spirobifluorene framework minimizes structural relaxation, and meanwhile, the introduction of a cyano (CN) group enhances the MR emission characteristics, leading to an ultra-narrowband blue emission with full width at half maximum (FWHM) of 14 nm. As a result, these molecules facilitate the assembly of narrowband blue CPL-OLEDs with a maximum external quantum efficiency (EQEmax) of 30.7% and an impressive narrow FWHM of 16 nm, representing the first instance of an FWHM below 20 nm in CPL-OLEDs.

Cyano-modified Potassium-Sodium Poly(Heptazine Imide) Nanosheets for Photocatalytic Hydrogen Peroxide Reduction Coupled with 5-hydroxymethylfurfural Oxidation

The efficacy of poly(heptazinonimide) (PHI) materials in photocatalytic applications is often constrained by limited visible light absorption and charge separation. In this study, we successfully synthesized cyano-modified potassium-sodium poly(heptazinonimide) (KNPHI) nanosheets using a molten salt method, which significantly enhances photocatalytic performance. The resulting KNPHI nanosheets achieve hydrogen peroxide (H₂O₂) concentrations up to 8.64mM, nearly 1.9 and 123 times greater than that achieved by KPHI and PCN respectively. Notably, integrating cyano groups and potassium-sodium ions within KNPHI enhances visible light absorption, intermediate adsorption and charge separation, as confirmed by experimental characterizations and DFT calculations, thereby improving the oxygen reduction reaction efficiency. Furthermore, the use of KNPHI for 5-hydroxymethylfurfural oxidation, coupled with oxygen reduction reaction pathway, was systematically investigated. These findings offer promising avenues for the development of advanced photocatalysts that support sustainable energy production and green chemical synthesis.

A new indanone based dyes bearing dicyanomethylene and salicylidene moieties for selective detection cyanide anion and aromatic amines

Novel chemosensors that are indan-1-one dyes bearing salicylidene moiety were synthesized with good yields and characterized by FT-IR, 1H NMR, 13C NMR, and HRMS methods. Moreover, the molecular structure of 7 was characterization by X-ray and Environmental scanning electron microscopy (ESEM) analyses. The chemosensor potential of dyes were examined in a variety of basic conditions that include various anions, organic amines, and pH ranges by absorption and fluorescence spectra. The naked-eye detection of instant color changes was also observed. The deprotonation mechanism between dyes and anions was investigated by reversibility and 1H NMR studies. pKa values were determined in buffer solution with pH 6–11. Furthermore, organic amines were investigated and found they have two different interaction mechanism, deprotonation and addition. Density Functional Theory (DFT) were used for supporting the experimental results. In addition, the second-order nonlinear optical property of dyes were investigated and showed moderate μβ values.

SYNTHESIS AND PHOTOPHYSICAL PROPERTIES OF NEW DIPHENYLACRYLONITRILE-BEARING ALDEHYDES

Background: The cyano group is well-known for its strong electron-withdrawing properties, Effective in producing acrylonitrile when added to ?-conjugated alkene structures. The twisted structures of acrylonitrile help avoid the ACQ phenomenon and induce AIE properties, making acrylonitrile units important in various applications. Aims: Synthesis of acrylonitrile units via cyano aldol condensation by temperature control and study of AIE activity. Methods: The synthesis of diphenyl acrylonitrile units took place in two steps: 1- By o-arylation, linear aldehydes were synthesized, 2- Gradually adding p-ansiyl cyanide to the linear aldehydes in a round flask containing methanol and KOH. Results: Diphenyl acrylonitrile units were synthesized, and their structures were identified using IR, 1HNMR, 13CNMR, and mass techniques. The photophysical results indicated that diphenylacrylonitrile-bearing aldehyde compounds have fluorescence with a wavelength ranging between 400-500 nm and moderate AIE activity. Discussion: The prepared diphenylacrylonitrile-bearing aldehydes units showed moderate AIE activity in the aggregation state, where the fluorescence intensity increases with increasing water percentage in the THF/H2O mixture and reaches its peak at 80%. The reason lies in the fact that the cyano group forms acrylonitrile with twisted structures, which avoids ACQ and enhances the AIE properties. Conclusions: by controlling the temperature and through a facile aldol condensation, phenylacrylonitrile units were synthesized in good yields. Their photophysical properties were studied, and they were found to have moderate AIE activity.