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https://hdl.handle.net/20.500.12713/2428

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Metal-support interaction in pt nanodisk-carbon nitride catalyst: insight from theory and experiment
(MDPI, 2024) Doustkhah, Esmail; Kotb, Ahmed; Balkan, Timuçin; Assadi, Mohammad Hussein Naseef
Metal-support interaction plays a critical role in determining the eventual catalytic activity of metals loaded on supporting substrates. This interaction can sometimes cause a significant drop in the metallic property of the loaded metal and, hence, a drop in catalytic activity in the reactions, especially in those for which low charge carrier transfer resistance is a necessary parameter. Therefore, there should be a case-by-case experimental or theoretical (or both) in-depth investigation to understand the role of support on each metal. Here, onto a layered porous carbon nitride (g-CN), we grew single crystalline Pt nanodisks (Pt@g-CN) with a lateral average size of 21 nm, followed by various characterisations such as electron microscopy techniques, and the measurement of electrocatalytic activity in the O-2 reduction reaction (ORR). We found that intercalating Pt nanodisks in the g-CN interlayers causes an increase in electrocatalytic activity. We investigated the bonding mechanism between carbon support and platinum using density functional theory and applied the d-band theory to understand the catalytic performance. Analysis of Pt's density of states and electronic population across layers sheds light on the catalytic behaviour of Pt nanoparticles, particularly in relation to their thickness and proximity to the g-CN support interface. Our simulation reveals an optimum thickness of similar to 11 angstrom, under which the catalytic performance deteriorates.
In-situ synthesis of SnO/CuSnO 3 nanostructures to catalyze azo dye degradation, CO 2 reduction, and amines direct alkylation reactions under visible light
(Elsevier, 2024) Padervand, Mohsen; Bargahi, Alireza; Eftekhari-Sis, Bagher; Saadi, Mina; Ghasemi, Shahnaz; Dawi, Elmuez A.; Labidi, Abdelkader; Mahmoudi, Ghodrat; Gargari, Masoumeh Servati
The extensive use of photocatalysis to address environmental concerns, energy production, and organic transformations has attracted attention in recent decades. The SnO/CSO photocatalytic materials were fabricated through a single-step hydrothermal method and comprehensively characterized using a muti-technique approach to demonstrate the physicochemical, morphological, and electronic features. According to the photocatalytic experiments, the SnO/CSO could remove >96% of acid blue 92 (AB92) azo dye under optimum conditions , with rate constant 2.37 x 10(-2) min(-1). Furthermore, the photocatalyst significantly outperformed commercial TiO2 (P25), in reducing CO2 to CO and CH4 with a production rate of 10.8 and 1.18 mu mol.g(-1).h(-1), respectively, under visible light irradiation. The successful direct alkylation of amines to valuable organic compounds within 10 min of the reaction time with a conversion selectivity of >90% was another capability of the materials, making it a good candidate for pharmaceutical synthesis purposes.
Novel benzoyl and acetyl pyrazine-2-carbohydrazonamide hybrid derivatives: Experimental and theoretical insights
(Elsevier B.V., 2024) Mahmoudi, Ghodrat; Garcia Santos, Isabel; Castiñeiras, Alfonso; Servati Gargari, Masoumeh; Frontera, Antonio; Safin, Damir A.
A series of novel benzoyl and acetyl pyrazine-2-carbohydrazonamide hybrid derivatives, namely N’-benzoylpyrazine-2-carbohydrazonamide (1), N’-(4-methylbenzoyl)pyrazine-2-carbohydrazonamide (2), N’-(2-phenylacetyl)pyrazine-2-carbohydrazonamide (3) and N’-(2-(1H-indol-3-yl)acetyl)pyrazine-2-carbohydrazonamide (4), were readily obtained using a metallic Na-assisted interaction of 2-cyanopyrazine with benzohydrazide, 4-methylbenzohydrazide, 2-phenylacetohydrazide or 2-(1H-indol-3-yl)acetohydrazide in dry MeOH. Compounds 1–4 were studied by a set of physical measurements, including FTIR, 1H NMR and UV–vis spectroscopy, while their crystal structures were elucidated by single crystal X-ray diffraction and the corresponding crystal packing was further studied in detail using the Hirshfeld surface analysis. Compounds 3 and 4 were found to adopt both the E- and Z-isomeric forms in DMSO‑d6. Molecules of the title compounds are linked via N[sbnd]H⋯O and N[sbnd]H⋯N hydrogen bonds and π⋯π interactions, yielding supramolecular aggregates. As it was found by the Hirshfeld surface analysis, molecules of 1–4 mainly interact through the H⋯X (X = H, C, N and O) and C⋯X (X = C and N) contacts. The molecular interactions were quantified and compared using DFT calculations, molecular electrostatic potential (MEP) analysis and quantum theory of atoms in molecules (QTAIM) analysis, highlighting the dominant role of hydrogen bonding interactions in governing the crystal packing. © 2024 The Author(s)
De novo drug design to suppress coronavirus RNA-Glycoprotein via PNA-Calcitonin
(Turkish Chemical Society, 15 Mayıs 2024) Alparslan, Levent; Akkurt, Barbaros; Agar, Soykan
De novo drug design has been studied utilizing the organic chemical structures of Salmon Calcitonin 9 - 19 and Peptide Nucleic Acid (PNA) to suppress Coronavirus Ribonucleic Acid (RNA)-Glycoprotein complex. PNA has a polyamide backbone and Thymine pendant groups to selectively bind and inhibit Adenine domains of the RNA-Glycoprotein complex. While doing so, molecular docking and molecular dynamics studies revealed that there is great inhibition docking energy (-12.1 kcal/mol) with significantly good inhibition constant (124.1 µM) values confirming the efficient nucleotide-specific silencing of Coronavirus RNA-Glycoprotein complex.
Structural and theoretical insights into the influence of thiocyanate ligands on divalent metal complexes with terpyridine derivatives
(Elsevier B.V., 2025) Bogdał, Weronika; Jurowska, Anna; Hodorowicz, Maciej; Szklarzewicz, Janusz; Mahmoudi, Ghodrat; Doustkhah, Esmail; Zangrando, Ennio; Frontera, Antonio
Four complexes with terpyridine derivative, thiocyanate anion, and selected d-electron metals were studied. The obtained complexes of the formulation [M(ftpy)(SCN)2(CH3OH)]•DMF (M = Mn (1), Co (2), Ni (3)) and [Cu(ftpy)(NCS)2]•H2O (4), where ftpy = 4′‐(furan-2-yl)-2,2′:6′,2′′‐terpyridine, were characterized using FTIR and UV–Vis spectroscopies, magnetic studies, elemental analysis, and single crystal X-ray crystallography. All compounds crystallize in a triclinic crystal system with space group P1¯ and 1–3 are isomorphous and isostructural. The effect of the modification of the terpyridine ligand and the presence of the thiocyanate ligand on the structure has been verified. Interesting dependence was found in the structure of compound 4, where the two thiocyanate ligands are differently coordinated, one via N and the other via S, and the formation of complex dimers connected through hydrogen bonds is observed. The π-stacking interactions and the resulting solid-state architectures of compounds 1–4 were inspected through a combination of DFT calculations, QTAIM, and NCIPlot analyses, and the stability of the complexes was studied by UV–Vis spectroscopy in various solvents. © 2024 The Author(s)
Supramolecular assemblies of Zn(II) complex based on dithiolate-amine binary ligands: Synthesis, crystal structure, Hirshfeld surface, DFT, molecular docking, and anticancer studies
(Elsevier, 2024) Bhattacharjee, Tirtha; Nath, Sourav; Baildya, Nabajyoti; Das, Alakesh; Pathak, Surajit; Molins, Elies; Mahmoudi, Ghodrat; Verma, Akalesh Kumar; Borah, Pranab; Adhikari, Suman
In this article, synthesis of the novel zinc(II) complex [Zn(tren)(i-mnt)] from diethylenetriamine (tren) and 1,1dicyano-2,2-ethylenedithiolate di-potassium salt (K2i-mnt) has been presented and characterized by spectroscopic methods. The trigonal bipyramidal geometry of [Zn(tren)(i-mnt)] in solid state has been confirmed by Xray diffraction analysis where stacked assembly of parallel chains interlinked by N-H & ctdot;S, N-H & ctdot;N, and C-H & ctdot;N type hydrogen bonds observed in 3D supramolecular packing. Hirshfeld Surface (HS) optimizations show prominent N & ctdot;H/H & ctdot;N (32%), S & ctdot;H/H & ctdot;S (21%), and C & ctdot;H/H & ctdot;C (18.5%) interactions that well corroborate with X-ray data. Moreover, Density Functional Theory (DFT) at B3LYP/6-31 g(d) and LMKLL/DZDP basis sets have been used to ascertain geometry and long-range interactions in the complex. In addition, DNA-binding analysis has been assessed by inspecting its binding capability to calf-thymus DNA (CT DNA) and cytotoxic effects of the complex, and K2i-mnt were investigated against Dalton's Lymphoma (DL) malignant cancer cells to assess their anticancer activity. The molecular docking study shows that the complex has a better binding affinity for 3DK8 (Protein Data Bank ID), leading to a higher inhibition constant and interactions.
Discrete versus polymeric structures of coordination compounds of copper (II) with (pyridin-2-yl)methylenenicotinohydrazide and a library of dicarboxylic acids
(ELSEVIER, 05.10.2024) Benito, Monica; Mahmoudi, Ghodrat; Molins, Elies; Zangrando, Ennio; Gargari, Masoumeh Servati; Frontera, Antonio; Safin, Damir A.
A series of copper(II) discrete and polymeric coordination compounds, namely [{CuL(H2O)}(2)(fum)] (1), [{CuL(H2O)}(2)(mes)] (2), [Cu2L2(glu)](n)2n(H2O) (32n(H2O)) and [Cu3L2(adi)(2)](n) (4) were fabricated from (pyridin-2-yl)methylenenicotinohydrazide (HL) and a library of dicarboxylic acids, namely fumaric acid (H(2)fum), mesaconic acid (H(2)mes), glutaric acid (H(2)glu) and adipic acid (H(2)adi), using evaporative crystallization, grinding and slurry synthesis methods. The obtained coordination compounds have been fully characterized by single crystal X-ray diffraction revealing different types of complexes depending on the linker length, viz. from dinuclear complexes for the shorter linkers (fumaric and mesaconic acids) to 1D and 2D coordination polymers for longer glutaric and adipic acids. Thermal stability and spectroscopic features (FTIR and diffuse reflectance) of complexes were also studied. For the nonpolymeric compounds 1 and 2, the supramolecular assemblies driven by a combination of antiparallel pi-stacking and hydrogen bonding interactions have been studied and compared using DFT calculations, MEP surface analysis and a combination of QTAIM and NCIplot computational tools.
Development of Electrically Conductive Wood-Based Panels for Sensor Applications
(MDPI, 17.11.2024) Kocoglu, Ozden Beste; Pretschuh, Claudia; Unterweger, Christoph; Kodal, Mehmet; Ozkoc, Guralp
This study investigates the development of electrically conductive panels for application as emergency detection sensors in smart house systems. These panels, composed of wood chips coated with polymeric methylene diphenyl isocyanate, were modified with carbon black and carbon fibers to enable detection of moisture, temperature, and pressure variations. Manufactured via hot pressing, the panels retained standard mechanical properties and exhibited stable performance under diverse environmental conditions. Carbon black-filled panels achieved electrical percolation at a lower filler concentration (5%) compared to carbon fiber-filled panels. The incorporation of carbon black reduced the electrical resistivity to 8.6 ohm·cm, while the addition of carbon fibers further decreased it to 7.7 ohm·cm. In terms of sensor capabilities, panels containing carbon fibers demonstrated superior sensitivity to moisture and pressure changes. However, carbon black was ineffective for temperature sensing. Among the carbon fiber-filled panels, those with 20 wt.% concentration exhibited the best performance for moisture and pressure detection, whereas panels with 40 wt.% carbon fiber content displayed the most reliable and consistent temperature-sensing properties.
Development of dispersive solid phase extraction method for the preconcentration of parathion ethyl as a simulant of nerve agent sarin from soil, plant and water samples prior to GC-MS determination
(SPRINGER, 27.08.2024) Bodur, Suleyman; Bodur, Sezin Erarpat; Tutar, Bahar Karademir; Bakirdere, Sezgin; Yagmuroglu, Ozan
In the presented study, an efficient and fast analytical method was developed for the determination of parathion ethyl as sarin simulant by gas chromatography-mass spectrometry (GC-MS). Dispersive solid phase extraction (DSPE) was performed to concentrate parathion ethyl from soil, plant and water samples. Reduced graphene oxide-iron (II, III) oxide (rGO-Fe3O4) nanocomposite was used as an adsorbent to collect the target analyte from the aqueous sample solutions. After the optimization of extraction/preconcentration parameters, optimum conditions for adsorbent amount, eluent type, mixing type/period, eluent volume and initial sample volume were determined as 15 mg, acetonitrile, vortex/30 s, 100 mu L and 10 mL, respectively. Under the optimum conditions, analytical performance of the developed DSPE-GC-MS method was evaluated in terms of limit of detection (LOD), limit of quantitation (LOQ) and dynamic range. Dynamic range, LOD and LOQ values were figured out to be 0.94-235.15 mu g/kg, 0.41 mu g/kg and 1.36 mu g/kg (mass based), respectively. Satisfactory percent recovery results (90.3-125% for soil, 93.5-108.7% for plant, 88.5-112.9% for tap water) were achieved for soil, plant and tap water samples which proved the accuracy and applicability of the developed method. It is predicted that the DSPE-GC-MS method can be accurately used for the detection of sarin in soil, plant and water samples taken from war territories.
Development of a Solidification of Floating Organic Droplet-Based Liquid-Liquid Microextraction Method Utilizing a Schiff Base Ligand for the Determination of Nickel at Trace Levels in Saint John’s Wort Tea Infusions by Matrix Matching Calibration Assisted Slotted Quartz Tube-Flame Atomic Absorption Spectroscopy
(Taylor and Francis Ltd., 2025) Atakol, Melike; Akbıyık, Hilal; Atakol, Arda; Yıldırım, Vedat; Bakırdere, Sezgin; Atakol, Orhan
A sensitive and economical analytical method involving the solidification of floating organic drop microextraction technique with a dispersive solvent is utilized for extraction and enrichment of nickel in St. John’s wort tea infusions. Bis-N,N′-(salicylidene)-1,3-propanediamine was used as the complexing agent. The analyses were done with a slotted quartz tube-flame atomic absorption spectrometer (FAAS). The experimental parameters for the preconcentration procedure were optimized. The developed method provided a 26.5-fold enhanced detection power compared to determination by conventional FAAS. The limits of detection and quantification were 24 and 79 µg/kg, respectively, within a linear range of 50–500 µg/kg. The applicability of the method was tested on infusions of two samples of St. John’s wort tea. Matrix matching was adopted to eliminate/minimize the interferences on the signal. Spiked experiments in which high recovery values in the range of 89.3–121.4% were obtained indicate the accuracy and validity of the method. © 2025 Taylor & Francis Group, LLC.
Design of poly(vinyl pyrrolidone) and poly(ethylene glycol) microneedle arrays for delivering glycosaminoglycan, chondroitin sulfate, and hyaluronic acid
(Taylor and Francis Ltd., 2025) Choupani, Andisheh; Temuçin, Elif Şevval; Çiftçi Eda; Bakan, Feray; Çamiç, Büşra Tuğba; Özkoç, Güralp; Sezen, Meltem; Korkusuz, Petek; Korkusuz, Feza; Bediz, Bekir
Osteoarthritis (OA) is a prevalent joint disorder characterized by cartilage and bone degradation. Medical therapies like glucosaminoglycan (GAG), chondroitin sulfate (CS), and hyaluronic acid (HA) aim to preserve joint function and reduce inflammation but may cause side effects when administered orally or via injection. Microneedle arrays (MNAs) offer a localized drug delivery method that reduces side effects. Thus, this study aims to demonstrate the feasibility of delivering GAG, CS, and HA using microneedles in vitro. An optimal needle geometry is crucial for the successful application of MNA. To address this, here we employ a multi-objective optimization framework using the non-dominated sorting genetic algorithm II (NSGA-II) to determine the ideal MNA design, focusing on preventing needle failure. Then, a three-step fabrication approach is followed to fabricate the MNAs. First, the master (male) molds are fabricated from poly(methyl methacrylate) using mechanical micromachining based on optimized needle geometry. Second, a micro-molding with Polydimethylsiloxane (PDMS) is used for the fabrication of production (female) molds. In the last step, the MNAs were fabricated by microcasting the hydrogels using the production molds. Light microscopy (LIMI) confirms the accuracy of the MNAs manufactured, and in vitro skin insertion tests demonstrate failure-free needle insertion. Subsequently, we confirmed the biocompatibility of MNAs by evaluating their impact on the L929 fibroblast cell line, human chondrocytes, and osteoblasts. © 2024 Informa UK Limited, trading as Taylor & Francis Group.
A pyrazinamide-benzenesulfonohydrazide hybrid N'-(phenylsulfonyl)pyrazine-2-carbohydrazonamide: Experimental and theoretical insights
(Elsevier Ltd, 2024) Alizadeh, Vali; Garcia Santos, Isabel; Castiñeiras, Alfonso; Mahmoudi, Ghodrat; Safin, Damir A
A pyrazinamide-benzenesulfonohydrazide hybrid N'-(phenylsulfonyl)pyrazine-2-carbohydrazonamide (1), which was studied by physical measurements and computational tools, is reported. Compound 1 was synthesized using a metallic Na-assisted interaction of 2-cyanopyrazine with benzenesulfonylhydrazine in dry methanol. Our newly developed synthetic approach allowed to obtain the title compound witht the yield of 74%, which is more than twice higher in comparison to the previously reported synthesis using pyrazine-2-carbohydrazonamide and benzenesulfonyl chloride. Molecules of the title compound are linked via N–H⋯O, C–H⋯Ph, S=O⋯2-pyrazine and π⋯π interactions. As it was found by the Hirshfeld surface analysis, molecules of 1 interact through H⋯X (X = H, C, N and O) contacts. Electronic properties of 1 were revealed using the Density Functional Theory (DFT) computations. 1 was expected to be a fourth-class toxicity, and it does not penetrate the blood-brain barrier, while can potentially be absorbed by the gastrointestinal tract. It was predicted that compound 1, which demonstrated the strongest activity against PLpro, Nsp3_range 207–379 MES and Nsp16_SAM site, are of interest to suppress activity of the SARS-CoV-2 proteins. Although the Ki value is slightly higher, the ligand efficiency scores for complex PLpro–1 were found to be characteristic for a Hit. © 2024 Elsevier Ltd
Zinc(II) coordination compound with N ′-(pyridin-2-ylmethylene) nicotinohydrazide: Synthesis, crystal structure, computational and cytotoxicity studies
(Elsevier science INC, 2024) Adhikari, Suman; Nath, Sourav; Kansız, Sevgi; Balidya, Nabajyoti; Paul, Anirban Kumar; Dege, Necmi; Şahin, Onur; Mahmoudi, Ghodrat; Verma, Akalesh Kumar; Safin, Damir A.
In this work, we report on the synthesis of a novel zinc(II) coordination compound [ZnL 2 ] ( 1 ), which was readily obtained from the reaction of Zn(OAc) & sdot; 2H 2 O and N ' -(pyridin-2-ylmethylene)nicotinohydrazide ( HL ) in methanol. Recrystallization of 1 from dimethylformamide under ambient conditions allowed to produce yellow blocklike crystals of 1 & sdot; H 2 O. Complex 1 & sdot; H 2 O was characterized by FT-IR and 1 H NMR spectroscopy, while its optical properties were studied by UV - vis and spectrofluorimetry in methanol. The crystal structure of the title complex was revealed by single crystal X-ray diffraction and further explored in detail by the Hirshfeld surface analysis. Theoretical investigations based on the DFT calculations have also been applied to show the electronic properties of complex 1 . The antitumor activities of the parent ligand HL and complex 1 were studied using Dalton ' s lymphoma malignant cancer model. Both compounds were found to induce concentration -dependent cytotoxicity and apoptotic cell death, leading to a decrease in cell viability, body weight, and tumor volume in mice with the superior activity of complex 1 over HL . Mice treated with complex 1 demonstrated an increase in life span with a survival period of 23 days. Finally, using a molecular docking approach, we have probed complex 1 to inhibit the recombinant mouse tumor -necrosis factor alpha (mTNF).
A novel tetrazole–1,8-naphthyridine–amide hybrid: First structurally characterized tetrazolo[1,5-a]-derivative of naphthyridines with a luminescence activity, potency against COVID-19, and anticancer activity
(Elsevier B.V., 2025) Adhikari, Suman; Nath, Sourav; Sen, Tanushree; Raza, Rameez; Şahin, Onur; Eftekhari Sis, Bagher; Mahmoudi, Ghodrat; Borah, Pranab; Verma, Akalesh Kumar; Safin, Damir A.
This contribution is devoted to a novel tetrazole–1,8-naphthyridine–amide hybrid N-(tetrazolo[1,5-a][1,8]naphthyridin-8-yl)butyramide (1), which was produced from N-(7‑chloro-1,8-naphthyridin-2-yl)butyramide by reacting with NaN3. In the crystalline state, molecules of 1 exhibited C–H···O intramolecular bonds and produced a 1D chain through N–H···N and C–H···N contacts. Chains produce a supramolecular 2D layer due to π···π interactions. In the UV–vis spectrum, 1 exhibits bands up to ∼360 nm and is emissive with a broad band from about 335 to 450 nm, with the maximum at 365 nm. Fine features of 1 were revealed using the density functional theory (DFT) calculations in water. The computed geometrical parameters are in accordance with the experimental values. The frontier electronic orbitals were found on the molecule except for the propyl fragment, and 1 was determined as a strong electrophile. The computed absorption, distribution, metabolism, elimination and toxicity (ADMET) features predicted positive gastrointestinal absorption (GA) activity and negative human blood-brain barrier (BBB) property of 1. Compound 1 in silico tested to inhibit some of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) proteins. Papain-like protease (PLpro) and Nonstructural protein 3 (Nsp3_range 207–379-MES) were established to interact with 1 more efficiently. The PLpro complex with 1 exhibits a ligand efficiency scores for a Hit. The present study also delved into elucidating the cytotoxic potential of compound 1 in Dalton's Lymphoma (DL) malignant cancer cell lines, aiming to explore its anticancer efficacy. Furthermore, this investigation extends its purview to scrutinize the cytotoxicity profile of the aforementioned compound on normal peripheral blood mononuclear cells (PBMCs), thus enabling a comprehensive comparative analysis of cellular responses under both neoplastic and non-neoplastic cell lines. © 2024 Elsevier B.V.
A lead(II)-N′-isonicotinoylpyrazine-2-carbohydrazonamide complex system as a converter of aerial carbon dioxide to carbonate under electrochemical conditions with the formation of a single-component white light-emitting phosphor
(Royal society of chemistry, 2024) Mahmoudi, Ghodrat; Garcia-Santos, Isabel; Labisbal, Elena; Castineiras, Alfonso; Alizadeh, Vali; Gomila, Rosa M.; Frontera, Antonio; Safin, Damir A.
In this contribution, a novel binuclear heteroleptic complex [Pb2L2(CO3)]2CH(3)CN2MeOH (12CH(3)CN2MeOH) is reported, which was fabricated by electrochemical oxidation of a lead anode under an ambient atmosphere in a CH3CN : MeOH solution of N '-isonicotinoylpyrazine-2-carbohydrazonamide (HL). The CO32- anion was produced from the conversion of aerial CO2 by the Pb2+-L complex system under electrochemical conditions. In the structure of 1, ligand L exhibits a tridentate pincer-like N,N ',O-coordination mode, while the CO32- anion exhibits a tetradentate bridging coordination mode with one of the oxygen atoms exhibiting a bridging mu-coordination mode. The metal cations in the structure of 1 are in a five-membered N2O3 coordination environment, formed by covalent bonds. The molecular structure of 12CH(3)CN2MeOH is stabilized by a pair of intermolecular Pb & ctdot;N tetrel bonds formed with one of the NH2 nitrogen atoms of an adjacent complex molecule and with the acetonitrile nitrogen atom, and one Pb & ctdot;O tetrel bond formed with the carbonyl oxygen atom of the other adjacent complex molecule, yielding a 2D supramolecular sheet. This sheet is further stabilized by intermolecular N-H & ctdot;N-acetonitrile and N-H & ctdot;O-carbonate hydrogen bonds and pi(Pyrazine)& ctdot;pi(Pyridine) interactions. The optical properties of the complex were revealed by UV-vis spectroscopy and spectrofluorimetry in MeOH. It was established that the described complex is emissive upon excitation at 340 nm with a broad band from about 500 nm to 780 nm with a maximum at similar to 580 nm, accompanied by a shoulder at similar to 620 nm. The CIE-1931 chromaticity coordinates of (0.28, 0.36) fall within the white gamut of the chromaticity diagram. Thus, complex 1 is a single-component white light-emitting phosphor.
Aerial carbon dioxide conversion to carbonate mediated by a lead(ii) complex with tridentate bipyridine containing a hydrazide ligand under electrochemical conditions yielding single-component white-light-emitting phosphors
(Royal Society of Chemistry, 2024) Mahmoudi, Ghodrat; Garcia Santos, Isabel; Labisbal, Elena; Castiñeiras, Alfonso; Alizadeh, Vali; Gomila, Rosa M.; Frontera, Antonio; Safin, Damir A.
A novel tetranuclear complex [Pb4L4(CO3)2]·4H2O (1·4H2O) is reported, which was obtained through the electrochemical oxidation of a lead anode under an ambient atmosphere in a CH3CN : MeOH solution of N’-isonicotinoylpicolinohydrazonamide (HL). CO32− anions were formed through the conversion of aerial CO2via the Pb2+-L complex system under electrochemical conditions. The ligand L links two Pb2+ cations through the carbonyl oxygen atom, while the CO32− anion links two Pb2+ cations through two monodentate and one bidentate oxygen atoms. The molecular structure of 1 is stabilized by a pair of Pb⋯O tetrel bonds formed with the bidentate oxygen atom of the CO32− anion, while molecules of 1 are interlinked through reciprocal π(chelate ring)⋯π(chelate ring), π(chelate ring)⋯π(noncovalent ring) and Pb⋯π(noncovalent ring) interactions, yielding a 1D supramolecular chain. The same reaction but under a nitrogen atmosphere yielded a novel mononuclear complex [PbL2]·MeOH·2H2O (2·MeOH·2H2O). In the structure of 2, each ligand L exhibits a tridentate coordination mode. Molecules of 2 are also interlinked through reciprocal π(chelate ring)⋯π(chelate ring), π(chelate ring)⋯π(noncovalent ring) and Pb⋯π(noncovalent ring) interactions, similar to 1, yielding a 1D supramolecular chain. The energetic features of these assemblies were studied using DFT calculations. Additionally, QTAIM analysis was employed to characterize noncovalent contacts, including intermolecular Pb⋯N tetrel bonds. These tetrel bonds were further analyzed using the ELF and Laplacian of electron density 2D maps, which confirmed their noncovalent nature. The optical properties of the complexes were revealed using UV-vis and diffuse reflectance spectroscopy and spectrofluorometry. Both complexes were found to be emissive in a solution of MeOH. CIE-1931 chromaticity coordinates of (0.38, 0.37) and (0.31, 0.32) for 1·4H2O and 2·MeOH·2H2O, respectively, fall within the white gamut of the chromaticity diagram. © 2024 The Royal Society of Chemistry.
Anion driven tetrel bonding dictated supramolecular architectures of lead(ii) with a zwitterionic form of polydentate N′-(piperidine-1-carbonothioyl)picolinohydrazonamide
(Royal society of chemistry, 2024) Mahmoudi, Ghodrat; Garcia-Santos, Isabel; Castineiras, Alfonso; Fernandez-Vazquez, Roi; Gargari, Masoumeh Servati; Gomila, Rosa M.; Frontera, Antonio
Two novel supramolecular heteroleptic complexes [Pb2L2(NO3)(2)](n) (1) and {[Pb3L3](ClO4)(3)}(n)3.25nH(2)O (23.25nH(2)O), obtained from N '-(piperidine-1-carbonothioyl)picolinohydrazonamide (HL) and Pb(NO3)(2) or Pb(ClO4)(2) in aqueous methanol are reported. A crucial role of the auxiliary ligand (NO3- vs. ClO4-) was revealed as a driving force for the formation of the resulting architecture of complexes, which, in turn, are dictated by the formation of tetrel bonds. Complex 1 is constructed from heteroleptic dinuclear centrosymmetric species [Pb2L2(NO3)(2)], which, in turn, are formed from the heteroleptic mononuclear symmetry related [PbL(NO3)] units, linked through a pair of bonds formed between the metal cations and the thioamide nitrogen atoms. The metal cations form a weaker tetrel bond with the symmetry related nitrate atoms, yielding a 1D polymeric chain structure. These chains are interlinked through N-H & ctdot;O hydrogen bonds, formed between the covalently coordinated nitrate oxygen atom and the NH2 hydrogen atom, yielding a 2D supramolecular architecture. Complex 23.25nH(2)O is constructed from the trinuclear species [Pb3L3](ClO4)(3). The trinuclear cation is constructed from three [PbL](+) cations interlinked through two Pb-S and two Pb-N bonds, formed with the thiocarbonyl sulfur atoms and the amide nitrogen atoms. The cations [Pb3L3](3+) are interlinked through two Pb-N and two Pb-S bonds yielding a 1D supramolecular polymeric cationic chain {[Pb3L3](3+)}(n). The two metal cations corresponding to two [PbL](+) units, linked through a pair of the Pb-S bonds, are additionally bridged by two oxygen atoms of one of the perchlorate anions with the formation of two Pb & ctdot;O tetrel bonds. The coordination spheres of the metal cations are filled by one of the oxygen atoms of two different perchlorate anions with the formation of tetrel bonds. One of these perchlorates also forms the N-H & ctdot;O hydrogen bond within the trinuclear unit [Pb3L3](ClO4)(3). 1D supramolecular chains {[Pb3L3](3+)}(n) are interlinked through a myriad of hydrogen bonds formed by the perchlorate anions and crystallized water molecules. The tetrel bonds involving the counterions (Pb & ctdot;O) have been also analysed by DFT calculations via a MEP surface plot and 2D maps of electron localization function (ELF), Laplacian of electron density (del(2)rho) and reduced density gradient (RDG), confirming their noncovalent nature.
Enhanced crystallinity through melt annealing of thermoplastic polyurethanes
(John wiley and sons inc, 2025) Akkoyun, Bahar Durak; Wis, Abdulmounem Alchekh; Yıldırım, Rümeysa; Makal, Ümit; Özkoç, Güralp; Kodal, Mehmet
This study evaluated the influence of melt annealing on thermoplastic polyurethane (TPU) synthesized via reactive extrusion, aiming to enhance TPU melt crystallization behavior. The melt annealing process involved reprocessing the polymer in a twin-screw extruder, leveraging a novel approach to manipulating crystallization behavior by optimizing melt annealing conditions to activate microphase separation. Differential scanning calorimetry analysis indicated increased nucleation density and a shift in peak crystallization temperature to higher values during cooling. Phase morphology was examined using scanning electron microscopy, while gel permeation chromatography was utilized to assess molecular weight changes. X-ray diffraction provided insights into TPU microstructural modifications, and mechanical properties were evaluated via tensile tests. Fourier-transform infrared spectroscopy was employed to analyze annealing-induced changes in the hard segment structure and interpolymer bonding. The findings demonstrated that annealing enhances mechanical properties, promotes microphase separation, and increases the energy available for movement and realignment of hard segments, thereby improving TPU's thermal stability. Precise control of annealing temperature was critical to prevent adverse effects on polymer morphology or molecular weight reduction. Annealing at 210 degrees C yielded the highest degree of crystallinity, optimizing mechanical properties and thermal stability.
A novel, extreme simple modification of low-cost pencil graphite electrode (PGE) by single-walled carbon nanotube/pyrenebutyric acid (SWCNT/PBA) nanostructure for sensitive and selective detection of adrenaline
(Springer, 2025) Mahmoudi, Ghodrat; Hosseinifard, Mojtaba; Moghadam, Ahmad Jamali; Gargari, Masoumeh Servati; Alizadeh, Vali
The electrochemical carbon nanotube (CNT)-based sensors may provide an effective answer to the growing need for qualitative and quantitative determination of biomolecules. However employing CNTs as interface nanomaterials in various electrode matrices has been challenging for researchers. The most important issues are uniform dispersion of CNTs due to their agglomeration and their interfacial connection with electrode matrices. The superiority of this work lies in its ability to overcome these shortcomings by simple and rapid procedures while remaining negligible sensor surface fouling, but also provides high sensitive, inexpensive, and selective determination of AD molecule. Our work presents the non-covalent functionalization of Single Wall Carbon Nanotubes (SWCNTs) by Pyrenebutyric Acid (PBA) through simple pi-stacking interaction for preserving their electronic structure and preventing their agglomeration in the dispersion step to develop a novel disposable sensor with many attractive analytical performance characteristics for Adrenaline (AD) determination. SWCNTs/PBA hybrid film on a low-cost PGE support have been developed involving soaking of greatly simplified solvent-treated GPE without any further pretreatment step into successfully dispersed SWCNTs/PBA in ethanol, which is a green solvent. The surface morphology of the SWCNTs/PBA nanostructured films were evaluated using Field-emission scanning electron microscopy (FE-SEM), being correlated with the electrochemical characteristics observed by cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) techniques. The heterogeneous electron transfer rate constant (ks) values 0.09, 0.15 and 0.40 s-1 were obtained for Bare PGE, PGE/SWCNT, and PGE/SWCNT/PBA electrodes, respectively. The obtained ks values have been shown that modification of SWCNTs with PBA improves the analytical properties of the sensor more than those obtained at bare PGE and SWCNTs/PGE due to synergistic effects. The analytical performance of SWCNTs/PBA/PGE was evaluated for AD oxidation in optimum pH 7.0 of phosphate buffer solution in the presence of an excess amount of interfering compounds by DPV technique. The fabricated sensor showed good response with high sensitivity, low detection limit (40 nM), wide linear range (0.25-9 mu M), and excellent reproducibility and repeatability. Also, the simultaneous analyses of AD and Uric Acid (UA) reveal that the fabricated sensor could separate the electrooxidation peaks of these two mixtures and good response with low detection limit (95nM) was also obtained for UA detection. The practical applicability of the fabricated sensor has been successfully tested for the determination of AD in human serum and injection ampoule samples with 98-110% recoveries.
Insights into One-Dimensional Thermoelectric Materials: A Concise Review of Nanowires and Nanotubes
(Multidisciplinary Digital Publishing Institute (MDPI), 2024) Latronico, Giovanna; Asnaashari Eivari, Hossein; Assadi, Mohammad Hussein Naseef
This brief review covers the thermoelectric properties of one-dimensional materials, such as nanowires and nanotubes. The highly localised peaks of the electronic density of states near the Fermi levels of these nanostructured materials improve the Seebeck coefficient. Moreover, quantum confinement leads to discrete energy levels and a modified density of states, potentially enhancing electrical conductivity. These electronic effects, coupled with the dominance of Umklapp phonon scattering, which reduces thermal conductivity in one-dimensional materials, can achieve unprecedented thermoelectric efficiency not seen in two-dimensional or bulk materials. Notable advancements include carbon and silicon nanotubes and Bi3Te2, Bi, ZnO, SiC, and Si1−xGex nanowires with significantly reduced thermal conductivity and increased ZT. In all these nanowires and nanotubes, efficiency is explored as a function of the diameter. Among these nanomaterials, carbon nanotubes offer mechanical flexibility and improved thermoelectric performance. Although carbon nanotubes theoretically have high thermal conductivity, the improvement of their Seebeck coefficient due to their low-dimensional structure can compensate for it. Regarding flexibility, economic criteria, ease of fabrication, and weight, carbon nanotubes could be a promising candidate for thermoelectric power generation. © 2024 by the authors.

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