Ortho-phenylenediamine Research Articles

Synthesis and structural studies on zinc(II) macrocyclic and hetrocyclic complexes derived from schiff base and mixed ligands of 1,4-dihydroquinoxaline-2,3-dione, orthophenylene diamine and hydroquinone

In this study two new zinc(II) complexes involving oxygen and nitrogen donor sequences derived from 1,4-dihydroquinoxaline-2,3-dione (QXD), o-phenylenediamine (OPD) and hydroquinone (HQ) were synthesized through a template procedure. The structural elucidation of these complexes was carried out using measurement of molar conductance in 1x10-3 M solution of DMSO and various spectral techniques; 1H and 13C NMR, FT-IR, UV-VIS and AAS. The results showed that the zinc(II) ion coordinates with the Schiff base ligands in octahedral geometry, leading to the formation of stable macrocyclic and heterocyclic structures. The cyclic ligand (L) was found to coordinate as NNNN donor, through four imine nitrogen atoms which were formed up on condensation of the –NH2 groups on o-phenylenediamine with C=O group on quinoxaline dione in a 2:2 mole ratio, in the presence of one mole equivalent of ZnCl2 in ethanol medium. It also indicates the formation of a new mixed ligand zinc(II) complex with an OO OO O O coordination around zinc(II). The study contributes to the understanding of the coordination chemistry of zinc(II) with Schiff bases and provides insights into the development of novel zinc-based complex compounds. KEY WORDS: Macrocyclic and mixed ligand, 1,4-Dihydroquinoxaline-2,3-dione, o-Phenylenediamine, Hydroquinone Bull. Chem. Soc. Ethiop. 2025, 39(1), 49-64. DOI: https://dx.doi.org/10.4314/bcse.v39i1.4

Colorimetric approach based on iron oxide magnetic molecularly imprinted nanozyme for sensitive determination of antipyrine and benzocaine: Application to environmental water samples and pharmaceutical dosage form

Nanozymes provide the required enzymatic activity however, they lack the selectivity to target a certain drug during analysis. Herein, a novel polydopamine molecularly imprinted polymer (MIP) was fabricated onto Fe3O4 nanozymes surface for sensitive and selective determination of antipyrine (ANT) and benzocaine HCl (BEN). Synthesized Fe3O4 nanozyme with peroxidase like activity catalyzed the oxidation of ortho phenylenediamine by the aid of H2O2 to produce intense yellow color that can be measured via colorimetric assay. The MIPs were prepared and characterized using field-emission scanning electronic microscopy, Fourier-transform IR spectroscopy, surface area analysis, and X-ray diffraction spectrum. Two Fe3O4 @ MIP NPs nanozyme with peroxidase like activity of two drugs were prepared. Upon binding of the target drug with its respective MIP, an inhibition in the Fe3O4 enzymatic activity occurred and thus a decrease in the yellow color produced. This quantitative decrease in the color intensity represents the drug concentration. Factors affecting the enzymatic colorimetric reaction have been investigated and optimized. The formed MIPs increased the sensitivity of the proposed method with LOD 1.405, 0.658 ng mL−1, LOQ 4.259, 1.993 and recovery percentage of 100.07, 100.57 for ANT and BEN, respectively. The reusability of the Fe3O4 @ MIP NPs was assessed for six cycles without significant loss in enzymatic oxidase activity. Furthermore, the method was validated following ICH guidelines. Then, it was successfully applied for determination of the two drugs in spiked environmental water samples and pharmaceutical formulation.

Exploring the anti-diabetic activity of benzimidazole containing Schiff base derivatives: In vitro α-amylase, α-glucosidase inhibitions and in silico studies

The current study explores the anti-diabetic potential of some Schiff bases containing benzimidazole scaffold. These derivative were synthesized by refluxing sodium metabisulfite with ethyl 2-(2-ethoxy-6-formylphenoxy)acetate followed by the addition of ortho phenylene diamine in DMF solvent to get the benzimidazole which was further refluxed in hydrazine hydrate to obtain the hydrazide. Finally various substituted benzaldehydes were treated with the desired hydrazide using a catalytic quantity of acetic acid to obtain the hydrazone Schiff bases. These compounds were evaluated for their ability to inhibit α-amylase and α-glucosidase inhibitory potentials. Among them, six derivatives including 2g, 2h, 2q, 2p, 2i, and 2m displayed noteworthy inhibitory activities against α-amylase (IC50 = 2.15 ± 0.17 µM to 15.18 ± 3.29 µM ) and α-glucosidase (IC50 = 4.21 ± 0.78 to 16.10 ± 0.52 µM) superior than the standard acarbose, while the remaining compounds showed significant to less inhibitory activities. By clarifying the mechanisms of interaction between the chemicals and amino acid residues, the molecular docking analysis attempted to shed light on the binding modalities of these molecules. The reactivity indices of these compounds were calculated using the Density Functional Theory (TD-DFT) approach, employing the B3LYP-d energy function and lacvp**(d,p) basis set for calculations. Schiff base derivatives based on benzimidazole, especially compounds 2h and 2g, exhibited lower electrophilicity and higher bioactivity compared to their counterparts 2i and 2m.

Dual-mode optical biocompatible-sensor enabled by enzyme-like activity of UiO-66 (Zr) for ultra-sensitive ROS detection in vitro

The simple, effective and highly sensitive detection of hydrogen peroxide (H2O2), which belongs to the reactive oxygen species (ROS), at low concentrations plays an indispensable role in the field of environmental protection, biological research and safety. In this study, a dual-mode optical biosensor, UiO-66@OPD, was developed based on the inherent peroxidase mimicking activity of UiO-66 (Zr) and the optical reaction of ortho-phenylenediamine (OPD) by extending the π-system through oxidative coupling, prototropism and elimination to form OPDox, thereby exhibiting strong orangish absorbance and greenish fluorescence. The catalase-mimicking activity of UiO-66 (Zr) was demonstrated by the catalytic oxidation of methylene blue in the presence of H2O2. Moreover, the Michaelis-Menten kinetic model confirmed the intrinsic peroxidase-like activity of UiO-66@OPD as a modified MOFzyme. The synthesized UiO-66 (Zr) facilitated the oxidation of OPD to OPDox by degrading H2O2 to the hydroxyl radicals. During the oxidation process, the absorption peak at 415 nm and the fluorescence peak at 565 nm of the synthesized probe were significantly enhanced by increasing the H2O2 concentration. Moreover, a colorimetric and fluorometric ultrasensitive sensor shows a good linear relationship between the intensity enhancement and H2O2 concentration in the range of 0–600 nM for absorption and fluorescence spectra with R2 = 0.9772, and R2 = 0.9948, respectively. To demonstrate the biological performance and biocompatibility of UiO-66@OPD as a biosensor, MTT evaluation was performed for the three cell lines MCF-10 A, HEK293 and A549, indicating high biocompatibility and good cell viability for biological applications. Ultimately, this convenient, environmentally friendly, biocompatible and cost-effective catalase-mimicking-based sensor system will open a new perspective for the development of portable kite-based biosensors In vitro.

Reductive carbon dots for reduction, ratiometric fluorescence determination, and intracellular imaging of Au3+

Many studies show that ortho-phenylenediamine (OPD) produces an oxidized fluorescent product when exposed to an oxidizing agent that enables the direct or indirect fluorescence detection of a range chemical and biochemical analytes. However, there is no report on this unique optical behavior for other two isomers of phenylenediamine. This study demonstrates that a simple hydrothermal treatment of para-phenylenediamine (PPD) in the presence of sulfuric acid results in the formation of fluorescent N, S-doped carbon dots (CDs) with triple functionalities including the reduction of Au3+ into gold nanoparticles (AuNPs), the stabilization of the produced AuNPs, and the determination of Au3+ concentration through an intrinsic ratiometric fluorescence signal. In the presence of Au3+, the blue emission of CDs at 437 nm quenched, and a green emission at 540 nm emerged. The linear concentration range for the determination of Au3+ was 20 nM–16 µM with a detection limit of 16 nM. Additionally, the dual emissive CDs-AuNPs hybrid probe showed potential for the indirect fluorescence ratiometric determination of cysteine and sulfide ions. The linear concentration range for cysteine and sulfide ions were 0.25–8 μM and 0.1–6 μΜ, with detection limits of 0.095 μM and 0.041 μM, respectively. Accordingly, CDs were applied to detect Au3+ and S2− in real water samples. Moreover, the synthesized CDs showed no cytotoxicity for HeLa cells up to 300 µg mL−1, as determined by the MTT assay. Therefore, their potential for intracellular imaging of Au3+ in living cells was also investigated.

Synthesis, Theoretical studies, and antibacterial activity of Novel Zn(II) metal complex with salicylaldehyde semicarbazone, and ortho phenylene diamine ligands.

Computational and experimental investigation of synthesized Zn(II) complex. Salicylaldehyde semicarbazone (SSC) and ortho phenylene diamine (OPDA) were the ligands for the preparation of Zn(II) metal complex. Using quantum chemistry simulations at DFT/B3LYP/LANL2DZ level of theory. FT-IR, UV, and Mass spectrometry methods were characterized the complex. The computed small gap energy demonstrated that the Zn(II) molecule had good biological activity. Measured dipole moment and first-order hyperpolarizability values were useful to investigate the complex NLO activity. Intra-molecular charge transfer, donor-acceptor transitions, and stabilization energies were determined by analyzing natural bond orbital (NBO) and Mulliken charges. Electrophilic and nucleophilic interactions were performed with the MEP map. QTAIM framework explained the nature of different intermolecular interactions within the molecule. Moreover, the ADMET studies of Zn(II) compound were also analyzed. The title molecule showed good antibacterial activity.

Design and synthesis of high-performance polymer blend solar cell

Conducting polymer blend of poly ortho-anthranilic acid and poly ortho-phenylene diamine (PANPDA) doped with HCl was synthesized in an aqueous solution using ferric chloride as an oxidizing agent and sodium dodecyl sulfate as a template. This study extends prior research in the field by characterizing the synthesized polymer blend, employing techniques such as ATR-Raman spectroscopy, SEM, and XRD. According to XRD analysis, PANPDA exhibited an orthorhombic crystal structure with a Pnn2 space group, while SEM indicated an average crystallite size (D) of 154.1 nm. Optical properties and laser photoluminescence of PANPDA films were investigated. Geometrical analysis was performed using time-dependent density functional theory (TD-DFT) and optimization via TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP). ATR-Raman, based on TD-DFT, revealed interactions between monomers leading to polymer blend nanofiber thin films. Within a wavelength range of 190–800 nm, the optical properties of PANPDA were studied. The direct energy gap calculated using TD-DFT was 1.875 eV. The refractive index had a maximum value of 1.93 at 1.63 for the polymer blend thin film. Laser photoluminescence spectra displayed an emission peak at λmax = 621.13 nm in PANPDA films. In the heterojunction Au/(PANPDA)/p-Si/Al, the fill factor (FF) and power conversion efficiency were found to be 41.60 % and 14.61 % at 240 W/cm2, respectively. The investigated optical energy bandgap in the nanofiber blend holds promise for various energy storage and solar cell applications.

Comprehensive Study of Chalcone Derivatives

Chalcones are flavonoid molecules that exist naturally and are essentially plant substances. These are the chemical compounds that have demonstrated a variety of intriguing biological actions with therapeutic potential against a variety of ailments. Anthranilic acid and orthophenylene diamine combine to produce benzimidazole. Additionally, the benzimidazole acetylated product goes via Claisen-Schmidt condensation with aryl aldehyde to create the respective chalcones. Due to phenolic groups and the existence of α, β unsaturated carbonyl groups, naturally occurring chalcones are polyhydroxylated in the aryl ring and exhibit a variety of biological activities, including antioxidant, antibacterial, antiinflammatory, and anticancer properties. Being natural precursors, chalcones are intermediates that are crucial for the synthesis of flavones. This review article emphasizes on the informative aspects, methods of synthesis, biological activities and applications of Chalcones.

Synthesis, Characterization, and Biological Evaluation of Bis(Aroyl Thiourea) Derivatives: Insights into Their Potential Applications through DFT Analysis

This study was aimed to synthesize and characterize a series of novel bis(thiourea) compounds (1–3) featuring ortho phenylenediamine substitutions and assess their potential biological properties. A range of analytical and spectroscopic techniques, including elemental analyses, UV–visible, FT-IR, NMR, and mass, were employed to confirm successful compound synthesis. Single-crystal X-ray diffraction was utilized to validate their crystal structures. Density functional theory calculations were conducted to compare optimized molecular geometries with experimental data. Furthermore, various molecular properties were assessed, indicating the potential suitability of these compounds for nonlinear optical applications. The compounds were also evaluated for their anticancer activity against MCF-7, A549, and Vero cells, demonstrating promising results. Additionally, the antioxidant properties of these new compounds were investigated using 1,1-diphenyl-2-picrylhydrazyl in spectrophotometric analysis. Compound 3 displayed notable antioxidant activity, evaluated in comparison with the standard drug ascorbic acid. In summary, this research introduces a promising series of compounds with potential applications in medicine and material science, without delving into specific numerical results and computational intricacies.

Spectrophotometric Determination of Cisplatin Using Derivatizing Agent

Background: Cisplatin is an anti-neoplastic agent used to treat cancer. In the U.V. range, Cisplatin has quite a low molar absorptivity. Hence, a Derivatization reaction is required for the spectrometric determination in the pharmaceutical dosage form.
 Objective: This paper aims to exemplify detail about the spectrophotometric study of Cisplatin using Derivatizing agent. 
 Method: Cisplatin has been estimated by Complexation with ortho-phenylene diamine at wavelength 705 nanometers.
 Results: The calibration curve was linear with a regression coefficient value of 0.999 in the concentration range of 0.5- 3.5 μg/ml. The technique was validated by determining different parameters and found to be satisfactory.
 Conclusion: The technique was efficiently helpful for the estimation of Cisplatin.

A Novel Class of Greenish‐Yellow Emitting Carbon Dots Stimulate Collective Cell Migration and 3D Uptake In Vivo**

AbstractWe present a new class of nitrogen‐doped greenish‐yellow fluorescent carbon dots (CDs) synthesized using a one‐step hydrothermal method. These bright fluorescent nanoparticles have excitation and emission spectra near the red region of the visible light spectrum which is quite useful for bioimaging applications. Using organic molecules like ortho‐phenylenediamine (OPDA), L‐ascorbic acid and urea, yellow fluorescent carbon dots (CDs) were synthesized. We obtained a scalable number of greenish‐yellow CDs having an average size of 3 nm. The CDs show significant emission spectra in the yellow fluorescence region (λem=557 nm). The CDs show remarkable stability in their fluorescence in different pH conditions, ionic stability, photostability as well as thermal stability. These CDs are efficiently uptaken by mammalian cells through the clathrin‐mediated pathway. Apart from in vitro studies, we have also used zebrafish larvae as a 3D in vivo model and showed that CDs were uptaken efficiently by larvae showing maximum accumulation and fluorescence in the yolk sac region and the notochord region. The CDs also offer enhancement in cell proliferation, hence showing the application in wound healing. The fluorescence of CDs is quite robust and is not affected by most external stimuli; therefore can be explored as a promising bioimaging tool for targeted bioimaging and biomedical applications.

Synthesis, characterization, biological studies and DFT study of Schiff Bases and their complexes derived from aromatic diamine compounds with cobalt (II)

Based on vanillin and diamine compounds (ortho phenylene diamine, meta phenylene diamine, 3,4- diamine toluene), derivation of two new Schiff base ligands (L1 and L2) was done, after which synthesis and treatment with Co (II) chloride was performed at a metal-to-ligand ratio of 1:1 to get two new complexes, i.e. [CoL3(H2O)2]Cl2 and [CoL1(H2O)2]Cl2. These complexes and ligands were characterized by employing NMR, IR, atomic absorption, UV visible absorption, molecular weight determination, molar conductance, and magnetic measurement techniques. As per the data, the ligands were found to be bidentate ligands that were linked to two azomethine nitrogen sites. It was suggested that these complexes were paramagnetic electrolyte compounds that possessed coordination number four. Screening of the ligands and metal complexes was done to assess their antimicrobial activities against gram-negative and gram-positive bacteria, which was found to show biological activity. Calculations using quantum chemistry were done to examine the molecule geometry. The investigation includes several quantum chemical characteristics derived from frontier molecular orbitals. Keywords: Schiff bases, transition metal complexes, vanillin, diamine aromatic compounds, antibacterial activity, DFT study.

Polymeric Solar Cell with 19.69% Efficiency Based on Poly(o-phenylene diamine)/TiO2 Composites.

Conducting poly orthophenylene diamine polymer (PoPDA) was synthesized via the oxidative polymerization route. A poly(o-phenylene diamine) (PoPDA)/titanium dioxide nanoparticle mono nanocomposite [PoPDA/TiO2]MNC was synthesized using the sol-gel method. The physical vapor deposition (PVD) technique was successfully used to deposit the mono nanocomposite thin film with good adhesion and film thickness ≅ 100 ± 3 nm. The structural and morphological properties of the [PoPDA/TiO2]MNC thin films were studied by X-ray diffraction (XRD) and scanning electron microscope (SEM). The measured optical properties of the [PoPDA/TiO2]MNC thin films such as reflectance (R) in the UV-Vis-NIR spectrum, absorbance (Abs), and transmittance (T) were employed to probe the optical characteristics at room temperatures. As well as the calculations of TD-DFT (time-dependent density functional theory), optimization through the TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-DFT/CASTEP) was employed to study the geometrical characteristics. The dispersion of the refractive index was examined by the single oscillator Wemple-DiDomenico (WD) model. Moreover, the single oscillator energy (Eo), and the dispersion energy (Ed) were estimated. The obtained results show that thin films based on [PoPDA/TiO2]MNC can be utilized as a decent candidate material for solar cells and optoelectronic devices. The efficiency of the considered composites reached 19.69%.

Ethanol Extract of Passiflora cincinnata Seeds Posses Antidiabetic, Antiglycant, and Antioxidant Activities in vitro

This work aimed to investigate the antidiabetic, antiglycation, and antioxidant potentials of the ethanol extract of seeds of Passiflora cincinnata (EPCIN) in vitro. The EPCIN was evaluated from the following assays: total phenolic content (TPC – mg of Gallic Acid Equivalents (GAE)/g of dry extract), Radical Scavenging Assays (DPPH•, HOCl-scavenging assay), and protective effects against glycation of bovine serum albumin (BSA) with methylglyoxal (MGO) or a mixture of reducing sugars, fructose and glucose, as well as the potential for MGO capture by derivatization with ortho-phenylenediamine (OPD). To evaluate the antidiabetic activity of EPCIN in vitro, we used the assays of enzymes α-amylase (4 U/mL), α-glucosidase (0.25 U/mL), and dipeptidyl peptidase-4 (DPP-4 – 3.125 mU). The cell viability of EPCIN-pretreated normal human bronchial epithelial cells (BEAS-2B) alone or in the presence of the carcinogen 4-[(acetoxymethyl)nitrosamine]-1-(3-pyridyl)-1-butanone (NNKOAc) was measured using MTS assay. Quercetin (QCT), piceatannol (PIC), acarbose (ACB), and sitagliptin (STG) were used for comparison purposes. EPCIN had an average of TPC 157.0 ± 1.5 mg of GAE/g of dry extract, exhibited IC50 for DPPH• and HOCl of 11.9 ± 1.8 μg/mL and 6.9 ± 0.9 μg/mL, respectively. EPCIN and AMG inhibited the formation of advanced glycation end-products (AGE) with IC50 of 574 ± 8.7 and 31.9 ± 2.7 μg/mL for the initial stage and 542.6 ± 2.7 and 52.8 ± 8.1 μg/mL for the intermediate stage of glycation, respectively. EPCIN showed IC50 for α-amylase and α-glucosidase of 218.2 ± 15.9 μg/mL (p<0,05) and 242.0 ± 25 μg/mL (p<0,05), respectively. EPCIN did not show cytotoxicity for BEAS-2B cells at 10 and 50 μg/mL concentrations. In addition, it was also able to protect cultured human cells from oxidative stress caused by the NNKOAc at 100 μM. The in vitro evidence of the potential antioxidant, antiglycant, and antidiabetic effects warrants further investigation of the antidiabetic potential of Passiflora cincinnata seeds.

Preparation of hybrid conducting polymers blend nanocomposite for energy conversion using experimental data and TD-DFT/DMOl3 computations

In the presence of sodium dodecyl sulphate in an acidic solution while using ferric chloride as an oxidizing agent, a blend of three conducting polymers of poly (ortho-phenylene diamine) (PoPDA), poly (meta phenylene diamine), and polypyrrole was produced. ZrO2 nanoparticles were prepared via sol-gel method and a hybrid nanocomposite of the three conducting polymers blend and zirconium oxide nanoparticles (TCPB/ZrO2)HNC was synthesized. Using the Physical Vapor Deposition technology, a hybrid nanocomposite thin film was prepared from (TCPB/ZrO2)HNC. Density functional theory (DFT) was also used to develop optimization using TD-DFTD/Mol3 and Cambridge Serial Total Energy Bundle (TD-FDT/CASTEP). By closely matching the reported XRD and Raman spectra, the TD-DFT computations validated the molecular structure of the studied materials and confirmed its molecular structure. According to XRD calculations, (TCPB/ZrO2)HNC has an average crystallite size of 61.67 nm. The direct and indirect optical energy bandgaps for the (TCPB/ZrO2)HNC, are 2.352 and 2.253 eV, respectively. As measured by TD-DFT/DMol3, the isolated molecule of (TCPB/ZrO2) HNC has a bandgap of 2.415 eV. The optical properties suggested by CASTEP in TD-DFT agree quite well with the values obtained experimentally. The large optical energy bandgap of (TCPB/ZrO2)HNC is advantageous for various energy storage applications.

Ethanol Extract of Passiflora cincinnata Seeds Posses Antidiabetic, Antiglycant, and Antioxidant Activities in vitro

This work aimed to investigate the antidiabetic, antiglycation, and antioxidant potentials of the ethanol extract of seeds of Passiflora cincinnata (EPCIN) in vitro. The EPCIN was evaluated from the following assays: total phenolic content (TPC – mg of Gallic Acid Equivalents (GAE)/g of dry extract), Radical Scavenging Assays (DPPH•, HOCl-scavenging assay), and protective effects against glycation of bovine serum albumin (BSA) with methylglyoxal (MGO) or a mixture of reducing sugars, fructose and glucose, as well as the potential for MGO capture by derivatization with ortho-phenylenediamine (OPD). To evaluate the antidiabetic activity of EPCIN in vitro, we used the assays of enzymes α-amylase (4 U/mL), α-glucosidase (0.25 U/mL), and dipeptidyl peptidase-4 (DPP-4 – 3.125 mU). The cell viability of EPCIN-pretreated normal human bronchial epithelial cells (BEAS-2B) alone or in the presence of the carcinogen 4-[(acetoxymethyl)nitrosamine]-1-(3-pyridyl)-1-butanone (NNKOAc) was measured using MTS assay. Quercetin (QCT), piceatannol (PIC), acarbose (ACB), and sitagliptin (STG) were used for comparison purposes. EPCIN had an average of TPC 157.0 ± 1.5 mg of GAE/g of dry extract, exhibited IC50 for DPPH• and HOCl of 11.9 ± 1.8 μg/mL and 6.9 ± 0.9 μg/mL, respectively. EPCIN and AMG inhibited the formation of advanced glycation end-products (AGE) with IC50 of 574 ± 8.7 and 31.9 ± 2.7 μg/mL for the initial stage and 542.6 ± 2.7 and 52.8 ± 8.1 μg/mL for the intermediate stage of glycation, respectively. EPCIN showed IC50 for α-amylase and α-glucosidase of 218.2 ± 15.9 μg/mL (p<0,05) and 242.0 ± 25 μg/mL (p<0,05), respectively. EPCIN did not show cytotoxicity for BEAS-2B cells at 10 and 50 μg/mL concentrations. In addition, it was also able to protect cultured human cells from oxidative stress caused by the NNKOAc at100 μM. The in vitro evidence of the potential antioxidant, antiglycant, and antidiabetic effects warrants further investigation of the antidiabetic potential of Passiflora cincinnata seeds.

Highly Luminescent and Semiconducting Supramolecular Organic Charge Transfer Complex Generated via H‐Bonding Interaction Pathway

AbstractThe construction of a charge transfer (CT) organic material with important electrical properties is demonstrated where the charge transfer state is generated via delocalization through H‐bonding interaction pathway. The reaction of simple organic molecule pyromellitic acid with orthophenylene diamine in 1:2 ratios gives a colorless cocrystal 1’. The rare transition phenomena of a colorless cocrystal 1’ to an orange charge transfer state 1 take place in methanol water media over several days. The charge transfer state is isolated as orange single crystals of 1 which show semiconducting as well as fluorescent properties. The X‐ray diffraction analysis of 1 demonstrates the formation of charge separated extended H‐bonded network which is supposed to be solely responsible for the delocalization of charge in the system. This is the first example of formation of donor–acceptor‐based charge transfer material constructed by just tuning the H‐bond distance of a colorless cocrystalline state with non‐chalcogen and non‐halogenated molecules.

N-Heterocyclic Carbene-Supported Nickel-Catalyzed Selective (Un)Symmetrical N-Alkylation of Aromatic Diamines with Alcohols

The "borrowing hydrogen" (BH) approach for the N-alkylation of phenylenediamines using alcohols as coupling partners is highly challenging due to the selectivity issue of the generated products. Furthermore, the development of base-metal systems that can potentially substitute precious metals with competitive activity is a major challenge in BH catalysis. We present herein an efficient protocol for the N,N'-di-alkylation of aromatic diamines using an in situ-generated Ni-NHC complex from NiCl2 and the ligand L1, which gave access to a wide range of N,N'-di-alkylated orthophenylene diamines (rather than the generally observed benzimidazole derivatives), meta- and para-phenylene diamines along with 2,6-diamino pyridine derivatives in good to excellent yields. Moreover, the catalyst system was also successful in the derivatization of a clinically important drug molecule, Dapsone. Notably, the present protocol could be applied effectively to synthesize unsymmetrically substituted N,N'-di-alkylated diamines via sequential alkylation and is the first report in the base-metal system to the best of our knowledge. Diverse control experiments including the deuterium incorporation studies suggest that the present protocol proceeds via a BH sequence.

Dual visible and near-infrared luminescence in mononuclear macrocyclic erbium(III) complexes via ligand and metal centred excitation.

Considering the structural design of some of the scarce molecular-based Er-centred emitters in the literature, we explored the optical properties of three ErIII hexaazamacrocyclic complexes, namely Er-EDA (1), Er-OPDA(2) and Er-DAP(3). The macrocyclic ligands in these complexes differ in the lateral spacers, and are derived from 2,6-pyridine-dicarbaldehyde and ethylenediamine (EDA), ortho-phenylenediamine (OPDA) or 1,3-diaminopropane (DAP). Upon ligand-centred excitation, the bluish-green and green emissions of the ErIII ion were detected only for the complexes containing macrocycles with aliphatic spacers (1 and 3), which evidenced that these ligands can sensitize the ErIII luminescence. On the other hand, the ligand derived from the aromatic diamine (2) does not sensitize the ErIII luminescence. Energy transfer mechanisms, temperature sensing, CIE coordinates and CCT values were analyzed. Besides the excitation in the ligands, the erbium-centred excitation at 980 nm allowed the detection, in all cases, of bluish-green, green and red up-converted emissions, and also the downshifted NIR emission. The possible mechanisms involved in these transitions were described and analyzed according to the available data.

One-dimensional ternary conducting polymers blend with 9.26% power conversion efficiency for photovoltaic devices applications

HCl doped-copolymer of ortho phenylene diamine, meta phenylene diamine, and pyrrole terpolymers blend was synthesized. Physical vapor deposition was used to produce the terpolymer-blended thin films, allowing the creation of the fiber structure at a low deposition rate, with a chamber pressure of 5 × 10−5 mbar and a thickness of 100 ± 2 nm. The produced thin films of terpolymers blend were examined utilizing a combination of theoretical and experimental techniques including TD-DFT/DMol3, CATSTEP, FT-IR spectrum, XRD, and optical characterizations. According to XRD computations, the terpolymers blend had an average crystallite size of 190 ± 2 nm, while SEM measurements showed that the length of the fibers was ≅ 73 ± 2 μm. The blend of terpolymers displayed an absorbance of 1.83 at 612 nm. Additionally, the blend of terpolymers' indirect/direct bandgap and absorption index was observed with noticeable alterations. The molecular structure optimization and frequency calculations for the crystal models and isolated molecules were carried out using the materials studio 7.0 tool (TDDFT/DMol3 and CASTEP). The DFT-Gaussian09W-vibration values closely matched the experimental results in terms of structure and optical characteristics. The application of thin films in polymer solar cell applications looks promising due to the noticeable improvements in optical characteristics.