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This study describes the non-covalent interactions of the charge transfer complex (CT), which was responsible for the synthesis of Linagliptin (LNG) with 2,3-Dichloro-5,6-Dicyano-1,4-benzoquinone (DDQ), or with Chloranilic acid (CHA) complexes in acetonitrile (MeCN) at temperatures of (25 ± 2 °C). Then, a UV–Vis spectrophotometer was utilized to identify Linagliptin (LNG) from these complexes. For the quantitative measurement of Linagliptin in bulk form, UV–Vis techniques have been developed and validated in accordance with ICH criteria for several aspects, including selectivity, linearity, accuracy, precision, LOD, LOQ, and robustness. The optimization of the complex synthesis was based on solvent polarization; the ratio of molecules in complexes; the association constant; and Gibbs energy (ΔG°). The experimental work is supported by the computational investigation of the complexes utilizing density functional theory as well as (QTAIM); (NCI) index; and (RDG). According to the optimized conditions, Beer’s law was observed between 2.5–100 and 5–100 µM with correlation coefficients of 1.9997 and 1.9998 for LGN-DDQ and LGN-CHA complexes, respectively. For LGN-DDQ and LGN-CHA complexes, the LOD and LOQ were (1.0844 and 1.4406 μM) and (3.2861 and 4.3655 μM), respectively. The approach was successfully used to measure LGN in its bulk form with high precision and accuracy.

Single-atom nanozymes (SAzymes) made of iron show great potential as artificial enzymes due to their consistent active sites closely resembling the active centers found in natural enzymes. They can be produced from accessible and affordable raw materials, making them suitable options for various applications. In the present research, Iron single-atom anchored N -doped carbon (Fe–N–C) as a laccase-mimicking nanozyme was prepared using 2-methylimidazole, Zinc nitrate, and Iron(II) chloride and characterized using various techniques. Fe–N–C/DDQ was used as a bioinspired oxidative cooperative catalytic system for the oxidation of 1,4-dihydropyridine and 2,3-dihydroquinazolinones to pyridines (87–96% yield), and quinazolinones (82–94% yield), respectively, with O 2 as a suitable oxidant in water/acetonitrile at room temperature. The main advantages and novelties of this method are: (1) this is the first time that the Fe–N–C SAzyme/DDQ catalyst system has been used for the aerobic oxidation of N -heterocyclic compounds (2) oxidation of a wide range of 1,4-dihydropyridines and 2,3-dihydroquinazolinones were performedusing an ideal oxidant with good to high yields under mild conditions (3) Fe–N–C SAzyme was prepared using a simple method and available and inexpensive raw materials system (4) Fe–N–C SAzyme couples the benefits of heterogeneous (easy separation and reusability) and homogeneous catalysts (high activity and reproducibility).

The purpose of our study is to determine the protective effects of the newly discovered molecule DDQ (diethyl (3,4-dihydroxyphenethylamino)(quinolin-4-yl) methylphosphonate) against aging in an in vitro, mouse primary hippocampal neurons, HT22 cells, and in vivo, 24-month-old C57BL6/J mice. Using biochemical and molecular methods, we studied the half-life period in the blood and brain, optimized the dose, determined dose-response (using 1, 5, 10, 20, and 50 mg/kg body weight), and measured the levels of blood, skeletal muscle, and brain. Using Morris water maze (cognitive behavior), q-RT-PCR (mRNA and protein levels of longevity genes SIRTUINS), transmission electron microscopy (mitochondrial number and length), and Golgi-Cox staining (dendritic spine number and length) were assessed in 24-month-old C57BL6/J mice. Out of 5 different doses of DDQ, the 20 mg/kg body weight dose showed the strongest protective effects against aging in C57BL6/J mice. The half-life time of DDQ is 20 h in the serum and 12 h in the brain. Our extensive pharmacodynamics analysis revealed high peak levels of DDQ in the skeletal muscle, followed by serum and brain. Using mouse primary hippocampal (HT22) neurons and 24-month-old C57BL6/J mice, we tested the protective effects of DDQ. Interestingly, longevity genes SIRTUINS were upregulated in DDQ-treated HT22 cells, and DDQ-treated aged wild-type mice relative to DDQ-untreated cells and untreated aged control mice. Dendritic spines and the quality of mitochondria were significantly increased in DDQ-treated aged mice. Current study findings, together with our previous study observations, strongly suggest that DDQ has anti-aging effects and warrants further investigations of anti-inflammatory, anti-DNA damage, and telomerase activity studies.

This study investigates the specific capacitance and electrochemical properties of a charge-transfer (CT) complex formed between 4,4′-bipyridine (BPy) and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ), focusing on its potential application as a redox-active component in advanced energy storage systems. A comprehensive series of electrochemical analyses was conducted to elucidate the electronic interactions and capacitive behavior of BPy in the presence of DDQ. Cyclic voltammetry (CV) revealed enhanced pseudocapacitive behavior, attributed to synergistic charge-transfer interactions between the nitrogen centers of BPy and the electron-deficient carbonyl groups of the nonequivalent derivative. The presence of C≡N and Cl substituents on the quinone ring was found to significantly influence the redox potentials and modulate the π–π* and n–π* charge-transfer processes, thereby affecting the electron density distribution within the molecular complex. Notably, the BPy–DDQ complex exhibited a high specific capacitance, reaching up to 114 F/g at a scan rate of 0.4 V/s, which is ascribed to enhanced charge delocalization and improved interfacial conductivity. Morphological analysis using scanning and transmission electron microscopy (SEM and TEM) further revealed the nanostructured features of the CT complex. These findings highlight the potential of BPy–DDQ complex as tunable, redox-active materials for next-generation supercapacitors and other electrochemical energy storage applications.

2,3-Dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) is a commonly known oxidant. Herein, we report that DDQ can be used to synthesize 1,2-disubstituted benzimidazoles and quinazolin-4(3 H )-ones via the intra- and intermolecular C–N coupling reaction under solvent-free mechanochemical (ball milling) conditions. In the presence of DDQ, the intramolecular C(sp 2 )–H amidation of N -(2-(arylideneamino)phenyl)- p -toluenesulfonamides leads to 1,2-disubstituted benzimidazoles and the one-pot coupling of 2-aminobenzamides with aryl/alkyl aldehydes resulted in substituted quinazolin-4(3 H )-one derivatives in high yields.

UV–Vis spectroscopy was used to investigate two new charge transfer (CT) complexes formed between the K+-channel-blocker amifampridine (AMFP) drug and the two π-acceptors 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and tetracyanoethylene (TCNE) in different solvents. The molecular composition of the new CT complexes was estimated using the continuous variations method and found to be 1:1 for both complexes. The formed CT complexes’ electronic spectra data were further employed for calculating the formation constants (KCT), molar extinction coefficients (εCT), and physical parameters at various temperatures, and the results demonstrated the high stability of both complexes. In addition, sensitive spectrophotometric methods for quantifying AMFP in its pure form were proposed and statistically validated. Furthermore, DFT calculations were used to predict the molecular structures of AMFP–DDQ and AMFP–TCNE complexes in CHCl3. TD-DFT calculations were also used to predict the electronic spectra of both complexes. A CT-based transition band (exp. 399 and 417 nm) for the AMFP–TCNE complex was calculated at 411.5 nm (f = 0.105, HOMO-1 → LUMO). The two absorption bands at 459 nm (calc. 426.9 nm, f = 0.054) and 584 nm (calc. 628.1 nm, f = 0.111) of the AMFP–DDQ complex were theoretically assigned to HOMO-1 → LUMO and HOMO → LUMO excitations, respectively.

The reactions of ketotifen fumarate (KT) with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as π acceptors to form charge transfer (CT) complexes were evaluated in this study. Experimental and theoretical approaches, including density function theory (DFT), were used to obtain the comprehensive, reliable, and accurate structure elucidation of the developed CT complexes. The CT complexes (KT-DDQ and KT-TCNQ) were monitored at 485 and 843 nm, respectively, and the calibration curve ranged from 10 to 100 ppm for KT-DDQ and 2.5 to 40 ppm for KT-TCNQ. The spectrophotometric methods were validated for the determination of KT, and the stability of the CT complexes was assessed by studying the corresponding spectroscopic physical parameters. The molar ratio of KT:DDQ and KT:TCNQ was estimated at 1:1 using Job’s method, which was compatible with the results obtained using the Benesi–Hildebrand equation. Using these complexes, the quantitative determination of KT in its dosage form was successful.

In order to design a high efficiency Wireless Electric Vehicle Charging (WEVC) system, the design of the different system components needs to be optimized, particularly the design of a high-coupling, misalignment-tolerant inductive link (IL), comprising primary and secondary charging coils. Different coil geometries can be utilized for the primary and the secondary sides, each with a set of advantages and drawbacks in terms of weight, cost, coupling at perfect alignment and coupling at lateral misalignments. In this work, a Finite Element Method (FEM)-based systematic approach for the design of double-D (DD) charging coils is presented in detail. In particular, this paper studies the effect of different coil parameters, namely the number of turns and the turn-to-turn spacing, on the coupling performance of the IL at perfect alignment and at ±200 mm lateral misalignment, given a set of space constraints. The proposed design is verified by an experimental prototype to validate the accuracy of the FEM model and the simulation results. Accordingly, FEM simulations are utilized to compare the performance of rectangular, DD and DDQ coils. The FEM results prove the importance of utilizing an additional quadrature coil on the secondary side, despite the added weight and cost, to further improve the misalignment tolerance of the proposed inductive link design.

Dynamic wireless charging (DWC) systems enable electric vehicles (EVs) to receive energy on the move, without stopping at charging stations. Nonetheless, the energy efficiency of DWC systems is affected by the inherent misalignments of the mobile EVs, causing fluctuations in the amount of energy transmitted to the EVs. In this work, a multi-coil secondary-side inductive link (IL) design is proposed with independent double-D (DD) and quadrature coils to reduce the effect of coupling fluctuations on the power received during misalignments. Dual-sided inductor–capacitor–capacitor (LCC) compensation networks are utilized with power and current control circuits to provide a load-independent, constant current output at different misalignment conditions. The LCC compensation components are tuned to maximize the power transferred at the minimum acceptable coupling point, kmin. This compensates for the leaked energy during misalignments and minimizes variations in the operating frequency during zero-phase angle (ZPA) operation. Simulations reveal an almost constant output power for different lateral misalignment (LTMA) values up to ±200 mm for a 25 kW system, with a power transfer efficiency of 90%. A close correlation between simulation and experimental results is observed.

This paper presents the expected and unexpected, but typically substituent-dependent, ferrocene-catalyzed DDQ-mediated oxidative transformations of a series of 5,8-bis(methylthio)-1-aryl-1,2-dihydropyridazino[4,5-d]pyridazines and 8-(3,5-dimethyl-1H-pyrazol-1-yl)-5-(methylthio)-1-aryl-1,2-dihydropyridazino[4,5-d]pyridazines. Under noncatalytic conditions the reactions were sluggish, mainly producing a substantial amount of undefined tarry materials; nevertheless, the ferrocene-catalyzed reactions of the 5,8-bis(methylthio)-substituted precursors gave the aromatic products the expected aromatic products in low yields. Their formation was accompanied by ring transformations proceeding via aryne-generating fragmentation/Diels–Alder (DA)/N2-releasing retro Diels–Alder (rDA) sequence to construct arene-fused phthalazines. On the other hand, neither the noncatalytic nor the catalytic reactions of the 8-pyrazolyl-5-methylthio-substituted dihydroaromatics yielded the expected aromatic products. Instead, depending on their substitution pattern, the catalytic reactions of these pyrazolyl-substituted precursors also led to the formation of dearylated arene-fused phthalazines competing with an unprecedented multistep fragmentation sequence terminated by the hydrolysis of cationic intermediates to give 4-(methylthio)pyridazino[4,5-d]pyridazin-1(2H)-one and the corresponding 3,5-dimethyl-1-aryl-1H-pyrazole. When 0.6 equivalents of DDQ were applied in freshly absolutized THF, a representative pyrazolyl-substituted model underwent an oxidative coupling to give a dimer formed by the interaction of the cationic intermediate, and a part of the N-nucleophilic precursor remained intact. A systematic computational study was conducted on these intriguing reactions to support their complex mechanisms proposed on the basis of the structures of the isolated products.