Pub Date : 2025-04-24DOI: 10.1186/s13065-025-01466-6
Israa A. Wahba, Said A. Hassan, Ahmed S. Fayed, Sally S. El-Mosallamy
This work presents two methods for the simultaneous determination of ibuprofen (IBU), paracetamol (PAR), and chlorzoxazone (CHZ) in the presence of three PAR impurities: p-aminophenol (PAP), p-nitrophenol (PNP), and p-chloroacetanilide (PCA). Furthermore, both methods attempt to quantify these hazardous impurities. The first method is a thin layer chromatography densitometric method (TLC), where separation was achieved on silica gel 60 F254 plates using a mobile phase consisting of chloroform, toluene, ethanol, and ammonia (7.0: 1.0: 1.6: 0.2, by volume). Densitometric detection was performed at 220.0 nm. The second method is a high-performance liquid chromatographic method (HPLC), in which the analytes were separated on an Xterra C8 column (150 × 4.6 mm, 5 µm) using an isocratic mobile phase of acetonitrile and phosphate buffer (pH 7.5) in a 30:70 (v/v) ratio. The UV detector was set at 220.0 nm, and the flow rate was maintained at 0.7 mL/min. Both methods were validated following ICH guidelines and successfully applied to the determination of IBU, PAR, and CHZ in their commercial tablet formulations. A statistical comparison with a previously reported method confirmed no discernible differences in the results, demonstrating the reliability and accuracy of the proposed techniques.
{"title":"Impurity profiling of paracetamol toxic impurities in pharmaceutical combination with ibuprofen and chlorzoxazone using HPLC and TLC densitometric methods","authors":"Israa A. Wahba, Said A. Hassan, Ahmed S. Fayed, Sally S. El-Mosallamy","doi":"10.1186/s13065-025-01466-6","DOIUrl":"10.1186/s13065-025-01466-6","url":null,"abstract":"<div><p>This work presents two methods for the simultaneous determination of ibuprofen (IBU), paracetamol (PAR), and chlorzoxazone (CHZ) in the presence of three PAR impurities: <i>p</i>-aminophenol (PAP), <i>p</i>-nitrophenol (PNP), and <i>p</i>-chloroacetanilide (PCA). Furthermore, both methods attempt to quantify these hazardous impurities. The first method is a thin layer chromatography densitometric method (TLC), where separation was achieved on silica gel 60 F<sub>254</sub> plates using a mobile phase consisting of chloroform, toluene, ethanol, and ammonia (7.0: 1.0: 1.6: 0.2, by volume). Densitometric detection was performed at 220.0 nm. The second method is a high-performance liquid chromatographic method (HPLC), in which the analytes were separated on an Xterra C8 column (150 × 4.6 mm, 5 µm) using an isocratic mobile phase of acetonitrile and phosphate buffer (pH 7.5) in a 30:70 (v/v) ratio. The UV detector was set at 220.0 nm, and the flow rate was maintained at 0.7 mL/min. Both methods were validated following ICH guidelines and successfully applied to the determination of IBU, PAR, and CHZ in their commercial tablet formulations. A statistical comparison with a previously reported method confirmed no discernible differences in the results, demonstrating the reliability and accuracy of the proposed techniques.</p></div>","PeriodicalId":496,"journal":{"name":"BMC Chemistry","volume":"19 1","pages":""},"PeriodicalIF":4.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://bmcchem.biomedcentral.com/counter/pdf/10.1186/s13065-025-01466-6","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143865516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-24DOI: 10.1021/acs.inorgchem.5c00906
Gaia Urciuoli, Antonio Vittoria, Francesco Zaccaria, Cristiano Zuccaccia, Roberta Cipullo, Peter H. M. Budzelaar, Leonardo Tensi, Christian Ehm, Alceo Macchioni, Vincenzo Busico
Well-defined Al-alkyl borate (AAB) salts {[iBu2(L)Al]2(μ-H)}+[B(C6F5)4]− (AlHAl_L) with L = N-donor ligands have been recently reported as promising “complete” cocatalysts for olefin polymerization. Herein, we explore structural variations of AlHAl_L going beyond the class of N-donors like the prototypical N,N-dimethyl aniline (DMA). Thirteen P-, O-, and C-donor ligands were screened, allowing isolation of AAB salts with mono- and bidentate phosphines, alkyl-, aryl-, and silyl-ethers, and a N-heterocyclic carbene. Except for the diphosphine with the longest spacer between the P atoms [bis(diphenylphosphino)hexane, DPPH], all donors gave well-defined tetracoordinate or tricoordinate molecular species, which were characterized in solution (NMR) and solid state (XRD), and tested as cocatalyst in ethylene/1-hexene copolymerization with an ansa-zirconocene catalyst [rac-Me2Si(2-Me-4-Ph-Ind)2ZrCl2]. The vast majority of novel AAB salts provided active catalytic systems, further demonstrating the broad tunability of these species. Consistent with previous studies, variability in productivity upon L variation is primarily related to the efficiency of precatalyst activation, determining the fraction of Zr active sites. Variations in polymer molecular weight and comonomer incorporation observed with some P-, O- and C-donor ligands indicate that also interactions between the L donors and the Zr active species might be relevant in determining catalytic performance in some cases.
{"title":"Borate Salts of Aluminum-Alkyl Cations Stabilized by P-, O-, and C-Donors: Synthesis, Characterization and Application as Cocatalysts","authors":"Gaia Urciuoli, Antonio Vittoria, Francesco Zaccaria, Cristiano Zuccaccia, Roberta Cipullo, Peter H. M. Budzelaar, Leonardo Tensi, Christian Ehm, Alceo Macchioni, Vincenzo Busico","doi":"10.1021/acs.inorgchem.5c00906","DOIUrl":"https://doi.org/10.1021/acs.inorgchem.5c00906","url":null,"abstract":"Well-defined Al-alkyl borate (AAB) salts {[<i>i</i>Bu<sub>2</sub>(<b>L</b>)Al]<sub>2</sub>(μ-H)}<sup>+</sup>[B(C<sub>6</sub>F<sub>5</sub>)<sub>4</sub>]<sup>−</sup> (<b>AlHAl_L</b>) with <b>L</b> = N-donor ligands have been recently reported as promising “complete” cocatalysts for olefin polymerization. Herein, we explore structural variations of <b>AlHAl_L</b> going beyond the class of N-donors like the prototypical <i>N,N</i>-dimethyl aniline (<b>DMA</b>). Thirteen P-, O-, and C-donor ligands were screened, allowing isolation of AAB salts with mono- and bidentate phosphines, alkyl-, aryl-, and silyl-ethers, and a N-heterocyclic carbene. Except for the diphosphine with the longest spacer between the P atoms [bis(diphenylphosphino)hexane, <b>DPPH</b>], all donors gave well-defined tetracoordinate or tricoordinate molecular species, which were characterized in solution (NMR) and solid state (XRD), and tested as cocatalyst in ethylene/1-hexene copolymerization with an <i>ansa</i>-zirconocene catalyst [<i>rac</i>-Me<sub>2</sub>Si(2-Me-4-Ph-Ind)<sub>2</sub>ZrCl<sub>2</sub>]. The vast majority of novel AAB salts provided active catalytic systems, further demonstrating the broad tunability of these species. Consistent with previous studies, variability in productivity upon <b>L</b> variation is primarily related to the efficiency of precatalyst activation, determining the fraction of Zr active sites. Variations in polymer molecular weight and comonomer incorporation observed with some P-, O- and C-donor ligands indicate that also interactions between the <b>L</b> donors and the Zr active species might be relevant in determining catalytic performance in some cases.","PeriodicalId":40,"journal":{"name":"Inorganic Chemistry","volume":"48 1","pages":""},"PeriodicalIF":4.6,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Juan L. Obeso, Luz Barrios-Vargas, Valeria López-Cervantes, Yoarhy Amador-Sánchez, Nancy Martín-Guaregua, Ricardo A. Peralta, Ramon Munoz, Ana Martínez, Carolina Leyva, Diego Solis-Ibarra, Elí Sánchez-González, Ilich A. Ibarra, Virginia Montiel-Palma
The adsorption and detection of SO2 using Zr-based MOF, NU-1000 grafted with an organometallic nickel silylphosphine complex ([NiSi]@NU-1000) via post-synthetic modification are reported. [NiSi]@NU-1000 exhibits high stability under dry and wet SO2, with a high cyclability performance. Moreover, fluorescence experiments postulate [NiSi]@NU-1000 as a promising SO2 detector due to its high SO2 selectivity over CO2 and air, showing an evident quenching effect, especially at low SO2 concentrations (0.1 bar of SO2). Time-resolved photoluminescence experiments suggest that host-guest SO2 interactions are associated with the turn-off effect.
{"title":"Selective detection of SO2 in NU-1000 via organometallic nickel silylphosphine post-synthetic complex incorporation","authors":"Juan L. Obeso, Luz Barrios-Vargas, Valeria López-Cervantes, Yoarhy Amador-Sánchez, Nancy Martín-Guaregua, Ricardo A. Peralta, Ramon Munoz, Ana Martínez, Carolina Leyva, Diego Solis-Ibarra, Elí Sánchez-González, Ilich A. Ibarra, Virginia Montiel-Palma","doi":"10.1039/d3dt03985d","DOIUrl":"https://doi.org/10.1039/d3dt03985d","url":null,"abstract":"The adsorption and detection of SO2 using Zr-based MOF, NU-1000 grafted with an organometallic nickel silylphosphine complex ([NiSi]@NU-1000) via post-synthetic modification are reported. [NiSi]@NU-1000 exhibits high stability under dry and wet SO2, with a high cyclability performance. Moreover, fluorescence experiments postulate [NiSi]@NU-1000 as a promising SO2 detector due to its high SO2 selectivity over CO2 and air, showing an evident quenching effect, especially at low SO2 concentrations (0.1 bar of SO2). Time-resolved photoluminescence experiments suggest that host-guest SO2 interactions are associated with the turn-off effect.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"5 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866466","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Azoarene molecular photoswitches with bistability are a family of widely employed structure-tuning units for photopharmacology and smart material construction. Notably, medium-ring azobenzenes, especially seven-membered dibenzo[b,f][1,4,5]thiadiazepines (DBTD), are characterized as fast-responsive T-type molecular photoswitches with particular features for light-energy conversion to ring-strain energy. The burgeon of azoheteroarenes with enhanced bistability and solubility have considerably broadened the horizon of their utilization. Herein, we present a novel class of seven-membered cyclic azoheteroarenes, benzo[b]pyrido[f][1,4,5]thiadiazepines (BPTD) and dipyrido[2,3-b:3',2'-f][1,4,5]thiadiazepine (DPTD). The integration of pyrido-heteroarenes in BPTD and DPTD enables pH-modulated T-type photoswitching performance spanning from pH = -0.33 to 7.0, distinguishing them from DBTD. Importantly, benzo[b]pyrido[3,4-f][1,4,5]thiadiazepine (3-BPTD) exhibits slightly enhanced photoswitching amplitude (photostationary distribution of E-isomers) as well as decent photo- and thermal stability in highly acidic environments. These features make them promising T-type photoswitches for potential acid-resistant light-energy converters and acid-endurable fast-responsive smart materials.
{"title":"Acidic pH Modulated Photoswitching of Sulfur-bridged Seven-membered Cyclic Azopyridines","authors":"Fengying Lan, Cefei Zhang, Zhihao Liu, Sitong Li, Jinmeng Yan, Xiaohu Zhao, Changwei Hu, Zhishan Su, Pengchi Deng, Zhipeng Yu","doi":"10.1039/d5qo00315f","DOIUrl":"https://doi.org/10.1039/d5qo00315f","url":null,"abstract":"Azoarene molecular photoswitches with bistability are a family of widely employed structure-tuning units for photopharmacology and smart material construction. Notably, medium-ring azobenzenes, especially seven-membered dibenzo[<em>b</em>,<em>f</em>][1,4,5]thiadiazepines (DBTD), are characterized as fast-responsive T-type molecular photoswitches with particular features for light-energy conversion to ring-strain energy. The burgeon of azoheteroarenes with enhanced bistability and solubility have considerably broadened the horizon of their utilization. Herein, we present a novel class of seven-membered cyclic azoheteroarenes, benzo[<em>b</em>]pyrido[<em>f</em>][1,4,5]thiadiazepines (BPTD) and dipyrido[2,3-<em>b</em>:3',2'-<em>f</em>][1,4,5]thiadiazepine (DPTD). The integration of pyrido-heteroarenes in BPTD and DPTD enables pH-modulated T-type photoswitching performance spanning from pH = -0.33 to 7.0, distinguishing them from DBTD. Importantly, benzo[<em>b</em>]pyrido[3,4-<em>f</em>][1,4,5]thiadiazepine (3-BPTD) exhibits slightly enhanced photoswitching amplitude (photostationary distribution of <em>E</em>-isomers) as well as decent photo- and thermal stability in highly acidic environments. These features make them promising T-type photoswitches for potential acid-resistant light-energy converters and acid-endurable fast-responsive smart materials.","PeriodicalId":97,"journal":{"name":"Organic Chemistry Frontiers","volume":"260 1","pages":""},"PeriodicalIF":5.4,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Noureddine IDLAHOUSSAINE, Brahim El Ibrahimi, Abdelaziz AIT ADDI, Walid DAOUDI, Rachid IDOUHLI, Mohammed LASRI, Murat YILMAZ, Mahmoud EL OUARDI, El aatiaoui Abdelmalik, Abdesselam ABOUELFIDA
The use of effective, environmentally friendly inhibitors is a promising strategy to mitigate metallic corrosion. This work involved the development of a newly developed imidazopyridine-based compound (i.e., MPPIP) and an assessment of its effectiveness as an anti-corrosive entity for the mild steel metal (MS) in 1.00M hydrochloric medium. The compound’s performance was evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), which demonstrated that MPPIP achieves 98% inhibition efficiency with 10⁻³ M concentration at the room temperature. The electrochemical analysis confirmed that MPPIP acts as a mixed-type inhibitor, reducing both anodic and cathodic reactions. Thermodynamic analyses revealed that MPPIP adsorption follows the Langmuir’s isotherm, involving a combination of physisorption and chemisorption mechanisms. Additional validation was performed using UV-Vis. spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), which revealed a uniform protective film on the steel surface, preventing metal dissolution. Computational approaches, including density functional theory (DFT) and Monte Carlo simulations, highlighted the molecule’s high electron-donating ability and strong adsorption energy, confirming its strong interaction with the metal surface. These findings demonstrate that MPPIP is a promising and efficient corrosion inhibitor for mild steel in acidic environments with an inexpensive and easily synthesized route characteristics.
{"title":"Investigating the Effectiveness of an Imidazopyridine-Based Compound as an Anti-corrosive Additive for Mild Steel in Molar Hydrochloric Solutions: A Mutual Multi-Facet Experimental and Computational Approach","authors":"Noureddine IDLAHOUSSAINE, Brahim El Ibrahimi, Abdelaziz AIT ADDI, Walid DAOUDI, Rachid IDOUHLI, Mohammed LASRI, Murat YILMAZ, Mahmoud EL OUARDI, El aatiaoui Abdelmalik, Abdesselam ABOUELFIDA","doi":"10.1039/d5cp00711a","DOIUrl":"https://doi.org/10.1039/d5cp00711a","url":null,"abstract":"The use of effective, environmentally friendly inhibitors is a promising strategy to mitigate metallic corrosion. This work involved the development of a newly developed imidazopyridine-based compound (i.e., MPPIP) and an assessment of its effectiveness as an anti-corrosive entity for the mild steel metal (MS) in 1.00M hydrochloric medium. The compound’s performance was evaluated using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS), which demonstrated that MPPIP achieves 98% inhibition efficiency with 10⁻³ M concentration at the room temperature. The electrochemical analysis confirmed that MPPIP acts as a mixed-type inhibitor, reducing both anodic and cathodic reactions. Thermodynamic analyses revealed that MPPIP adsorption follows the Langmuir’s isotherm, involving a combination of physisorption and chemisorption mechanisms. Additional validation was performed using UV-Vis. spectroscopy, scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX), which revealed a uniform protective film on the steel surface, preventing metal dissolution. Computational approaches, including density functional theory (DFT) and Monte Carlo simulations, highlighted the molecule’s high electron-donating ability and strong adsorption energy, confirming its strong interaction with the metal surface. These findings demonstrate that MPPIP is a promising and efficient corrosion inhibitor for mild steel in acidic environments with an inexpensive and easily synthesized route characteristics.","PeriodicalId":99,"journal":{"name":"Physical Chemistry Chemical Physics","volume":"53 1","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866575","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Organoalkoxysilanes (e.g. R–SiMe3-n(OR’)n, 1 ≤ n ≤ 3 with R=alkyl or aryl) have found various applications in synthetic chemistry and materials science because the silicon-bound alkoxy groups provide unique opportunities for further derivatization and transformations. Among the few catalytic strategies that allow the direct and intermolecular introduction of an alkoxysilyl unit onto an organic substrate, the alkoxysilylation of unactivated C–H bonds has barely been achieved despite its synthetic potential and the atom-economy it conveys. In particular, a catalytic and transition metal-free C–H silylation protocol towards this class of organosilicon compounds has yet to be reported. We herein describe the first general alkoxysilylation of (hetero)arene C(sp2)–H and benzylic C(sp3)–H bonds under ambient, transition metal-free conditions using newly-prepared tert-butyl-substituted alkoxysilyldiazenes (tBu–N=N–SiMe3-n(OR’)n, 1 ≤ n ≤ 3 with R’=Et, iPr or tBu) as silylating reagents and tBuOK as catalytic promoter.
{"title":"Catalytic Alkoxysilylation of C–H bonds with tert-Butyl-Substituted Alkoxysilyldiazenes","authors":"Lamine Saadi, Loïc Valade, Clément Chauvier","doi":"10.1039/d5sc02059j","DOIUrl":"https://doi.org/10.1039/d5sc02059j","url":null,"abstract":"Organoalkoxysilanes (e.g. R–SiMe<small><sub>3-n</sub></small>(OR’)<small><sub>n</sub></small>, 1 ≤ n ≤ 3 with R=alkyl or aryl) have found various applications in synthetic chemistry and materials science because the silicon-bound alkoxy groups provide unique opportunities for further derivatization and transformations. Among the few catalytic strategies that allow the direct and intermolecular introduction of an alkoxysilyl unit onto an organic substrate, the alkoxysilylation of unactivated C–H bonds has barely been achieved despite its synthetic potential and the atom-economy it conveys. In particular, a catalytic and transition metal-free C–H silylation protocol towards this class of organosilicon compounds has yet to be reported. We herein describe the first general alkoxysilylation of (hetero)arene C(sp<small><sup>2</sup></small>)–H and benzylic C(sp<small><sup>3</sup></small>)–H bonds under ambient, transition metal-free conditions using newly-prepared <em>tert</em>-butyl-substituted alkoxysilyldiazenes (<em>t</em>Bu–N=N–SiMe<small><sub>3-n</sub></small>(OR’)<small><sub>n</sub></small>, 1 ≤ n ≤ 3 with R’=Et, <em>i</em>Pr or <em>t</em>Bu) as silylating reagents and <em>t</em>BuOK as catalytic promoter.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"80 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ammonia, as a carbon-free fuel and promising hydrogen carrier, has attracted significant attention in the context of a net-zero-emission scenario. Photocatalytic ammonia decomposition is a promising approach for hydrogen production, and much attention has been given to this area in recent years. This mini-review summarizes the latest research progress in photocatalytic ammonia decomposition for hydrogen production. We mainly focus on the photocatalytic decomposition of aqueous ammonia solution and gaseous ammonia. For aqueous ammonia solution, various semiconductor-based catalysts are introduced, and the role of water is discussed. The formation of the ∙NH2 radical as a key species in the decomposition was proposed by different groups. In the case of gaseous ammonia, different types of catalysts, including semiconductor-based and localized surface plasmon resonance (LSPR)-based ones, are described. The mechanisms of ammonia decomposition, such as the N−N recombination and the N2Hy dehydrogenation, are discussed. Methods for accurate temperature measurement in the photocatalytic process are summarized. We conclude that photocatalytic ammonia decomposition has unique advantages in high activity, mild conditions, green process, and fast response. Moreover, the excellent catalyst, efficient utilization of light, and suitable reactor design are critically important for the practical application of photocatalytic ammonia decomposition.
{"title":"Hydrogen Production via Photocatalytic Ammonia Decomposition","authors":"Qijun Pei, Yongyu Wang, Khai Chen Tan, Jianping Guo, Teng He, Ping Chen","doi":"10.1039/d5sc01834j","DOIUrl":"https://doi.org/10.1039/d5sc01834j","url":null,"abstract":"Ammonia, as a carbon-free fuel and promising hydrogen carrier, has attracted significant attention in the context of a net-zero-emission scenario. Photocatalytic ammonia decomposition is a promising approach for hydrogen production, and much attention has been given to this area in recent years. This mini-review summarizes the latest research progress in photocatalytic ammonia decomposition for hydrogen production. We mainly focus on the photocatalytic decomposition of aqueous ammonia solution and gaseous ammonia. For aqueous ammonia solution, various semiconductor-based catalysts are introduced, and the role of water is discussed. The formation of the ∙NH<small><sub>2</sub></small> radical as a key species in the decomposition was proposed by different groups. In the case of gaseous ammonia, different types of catalysts, including semiconductor-based and localized surface plasmon resonance (LSPR)-based ones, are described. The mechanisms of ammonia decomposition, such as the N−N recombination and the N<small><sub>2</sub></small>H<small><sub>y</sub></small> dehydrogenation, are discussed. Methods for accurate temperature measurement in the photocatalytic process are summarized. We conclude that photocatalytic ammonia decomposition has unique advantages in high activity, mild conditions, green process, and fast response. Moreover, the excellent catalyst, efficient utilization of light, and suitable reactor design are critically important for the practical application of photocatalytic ammonia decomposition.","PeriodicalId":9909,"journal":{"name":"Chemical Science","volume":"31 1","pages":""},"PeriodicalIF":8.4,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fabian Dankert, Simon P. Muhm, Chandan Nandi, Sergi Danés, Sneha Mullassery, Petra Herbeck-Engel, Bernd Morgenstern, Robert Weiss, Pedro Salvador, Dominik Munz
The oxidation of triphenylphosphine by perfluorinated phenaziniumF aluminate in difluorobenzene affords hexaaryl-1,2-diphosphonium dialuminate 1. Dication 12+ is valence isoelectronic with elusive hexaphenylethane, where instead the formation of a mixture of the trityl radical and Gomberg’s dimer is favored. Quantum-chemical calculations in combination with Raman/IR spectroscopies rationalize the stability of the P–P bonded dimer in 12+ and suggest, akin to the halogens, facile homolytic as well as heterolytic scission. Thus, 12+ serves as a surrogate of both the triphenylphosphorandiylium dication (Ph3P2+) and the triphenylphosphine radical monocation (Ph3P·+). Treating 1 with dimethylaminopyridine (DMAP) or tBu3P replaces triphenylphosphine under heterolytic P–P bond scission. Qualifying as a superoxidant (E vs Fc/Fc+ = +1.44 V), 1 oxidizes trimethylphosphine. Based on halide abstraction experiments (–BF4, –PF6, –SbCl6, –SbF6) as well as the deoxygenation of triethylphosphine oxide, triflate anions as well as toluic acid, 1 also features Lewis superacidity. The controlled hydrolysis affords Hendrickson’s reagent, which itself finds broad use as a dehydration agent. Formally, homolytic P–P bond scission occurs with diphenyldisulfide (PhSSPh) and the triple bonds in benzo- and acetonitrile. The irradiation by light cleaves the P–P bond homolytically and generates transient triphenylphosphine radical cations, which engage in H-atom abstraction as well as CH phosphoranylation.
{"title":"Hexaphenyl-1,2-Diphosphonium Dication [Ph3P–PPh3]2+: Superacid, Superoxidant, or Super Reagent?","authors":"Fabian Dankert, Simon P. Muhm, Chandan Nandi, Sergi Danés, Sneha Mullassery, Petra Herbeck-Engel, Bernd Morgenstern, Robert Weiss, Pedro Salvador, Dominik Munz","doi":"10.1021/jacs.5c01271","DOIUrl":"https://doi.org/10.1021/jacs.5c01271","url":null,"abstract":"The oxidation of triphenylphosphine by perfluorinated phenazinium<sup>F</sup> aluminate in difluorobenzene affords hexaaryl-1,2-diphosphonium dialuminate <b>1</b>. Dication <b>1</b><sup><b>2+</b></sup> is valence isoelectronic with elusive hexaphenylethane, where instead the formation of a mixture of the trityl radical and Gomberg’s dimer is favored. Quantum-chemical calculations in combination with Raman/IR spectroscopies rationalize the stability of the P–P bonded dimer in <b>1</b><sup><b>2+</b></sup> and suggest, akin to the halogens, facile homolytic as well as heterolytic scission. Thus, <b>1</b><sup><b>2+</b></sup> serves as a surrogate of both the triphenylphosphorandiylium dication (Ph<sub>3</sub>P<sup>2+</sup>) and the triphenylphosphine radical monocation (Ph<sub>3</sub>P<sup>·+</sup>). Treating <b>1</b> with dimethylaminopyridine (DMAP) or <i><sup>t</sup></i>Bu<sub>3</sub>P replaces triphenylphosphine under heterolytic P–P bond scission. Qualifying as a superoxidant (<i>E</i> vs Fc/Fc<sup>+</sup> = +1.44 V), <b>1</b> oxidizes trimethylphosphine. Based on halide abstraction experiments (<b><sup>–</sup></b>BF<sub>4</sub>, <b><sup>–</sup></b>PF<sub>6</sub>, <b><sup>–</sup></b>SbCl<sub>6</sub>, <b><sup>–</sup></b>SbF<sub>6</sub>) as well as the deoxygenation of triethylphosphine oxide, triflate anions as well as toluic acid, <b>1</b> also features Lewis superacidity. The controlled hydrolysis affords Hendrickson’s reagent, which itself finds broad use as a dehydration agent. Formally, homolytic P–P bond scission occurs with diphenyldisulfide (PhSSPh) and the triple bonds in benzo- and acetonitrile. The irradiation by light cleaves the P–P bond homolytically and generates transient triphenylphosphine radical cations, which engage in H-atom abstraction as well as CH phosphoranylation.","PeriodicalId":49,"journal":{"name":"Journal of the American Chemical Society","volume":"24 1","pages":""},"PeriodicalIF":15.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jens Wöhnert, Konstantin Neissner, Elke Duchardt-Ferner, Christoph Wiedemann, Julian Kraus, Ute A. Hellmich
Phosphodiester groups occur ubiquitously in nature, e.g. in nucleic acids or in cyclic (di-)nucleotides important for signal transduction. Proteins often use polar or positively charged amino acids to interact with the negatively charged phosphodiester groups via hydrogen bonds and salt bridges. In contrast, the acidic amino acids aspartate and glutamate are generally not considered as important determinants for phosphodiester group recognition. Instead they are regarded as detrimental to such interactions due to the assumed charge repulsion between their deprotonated, negatively charged side chain carboxylate groups and the phosphodiester. Accordingly, acidic amino acids are often purposefully introduced into proteins to abrogate nucleic acid interactions in functional studies. Here, we show that in appropriate structural contexts glutamate side chains are readily protonated even at neutral pH and act as hydrogen bond donors to phosphodiester groups using a c-di-GMP binding protein – the GSPII-B domain of PilF from Thermus thermophilus – as an example. Surveying available RNA-protein and DNA-protein complex structures in the PDB, we found that hydrogen bonds between protonated carboxylate groups of glutamate and aspartate and phosphodiester groups occur frequently in different functional protein classes. Thus, the functional role of acidic amino acids in phosphodiester group recognition needs to be re-evaluated.
{"title":"Protonated Glutamate and Aspartate Side Chains Can Recognize Phosphodiester Groups via Strong and Short Hydrogen Bonds in Biomacromolecular Complexes","authors":"Jens Wöhnert, Konstantin Neissner, Elke Duchardt-Ferner, Christoph Wiedemann, Julian Kraus, Ute A. Hellmich","doi":"10.1002/anie.202501589","DOIUrl":"https://doi.org/10.1002/anie.202501589","url":null,"abstract":"Phosphodiester groups occur ubiquitously in nature, e.g. in nucleic acids or in cyclic (di-)nucleotides important for signal transduction. Proteins often use polar or positively charged amino acids to interact with the negatively charged phosphodiester groups via hydrogen bonds and salt bridges. In contrast, the acidic amino acids aspartate and glutamate are generally not considered as important determinants for phosphodiester group recognition. Instead they are regarded as detrimental to such interactions due to the assumed charge repulsion between their deprotonated, negatively charged side chain carboxylate groups and the phosphodiester. Accordingly, acidic amino acids are often purposefully introduced into proteins to abrogate nucleic acid interactions in functional studies. Here, we show that in appropriate structural contexts glutamate side chains are readily protonated even at neutral pH and act as hydrogen bond donors to phosphodiester groups using a c-di-GMP binding protein – the GSPII-B domain of PilF from Thermus thermophilus – as an example. Surveying available RNA-protein and DNA-protein complex structures in the PDB, we found that hydrogen bonds between protonated carboxylate groups of glutamate and aspartate and phosphodiester groups occur frequently in different functional protein classes. Thus, the functional role of acidic amino acids in phosphodiester group recognition needs to be re-evaluated.","PeriodicalId":125,"journal":{"name":"Angewandte Chemie International Edition","volume":"32 1","pages":""},"PeriodicalIF":16.6,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867043","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-04-24DOI: 10.1021/acs.langmuir.5c00065
Wei Hu, Yang Yang, Yunan Li, Fei Xu, Fubing Bao, Zhekai Gao, Xiaolong Li, Xiaoyan Gao
The study developed a thermoresponsive film to achieve autonomous fluid driving in microfluidic channels, simplify microfluidic systems, and improve their operability. This film has a lower critical solution temperature (LCST), exhibiting different wettabilities on each side of the LCST, and showed improved hydrophilicity-to-hydrophobicity conversion with increased substrate roughness, maintaining stability after repeated cycles. The thermoresponsive film was applied to the inner wall of the glass capillary, which showed a hydrophilic and enhanced capillary effect below the LCST and a hydrophobic and weakened capillary effect above the LCST. Subsequently, the modified capillary was placed under a dynamic temperature gradient, and the force analysis of the fluid in the flow channel was carried out. It was found that only when the driving force exceeded the axial resistance could the fluid migrate. Experimental analysis showed that fluid length was directly proportional to axial resistance and inversely proportional to both driving force and migration velocity at a constant dynamic temperature gradient. Additionally, the temperature of the hot end of the capillary was varied to form different dynamic temperature gradients. A higher dynamic temperature gradient resulted in greater fluid displacement and velocity at a constant fluid length. The results presented in this study were expected to provide new insights into the design and optimization of thermally driven microfluidic systems.
{"title":"Thermoresponsive Film Enhances Fluid Migration within the Capillary under a Dynamic Wettability Gradient","authors":"Wei Hu, Yang Yang, Yunan Li, Fei Xu, Fubing Bao, Zhekai Gao, Xiaolong Li, Xiaoyan Gao","doi":"10.1021/acs.langmuir.5c00065","DOIUrl":"https://doi.org/10.1021/acs.langmuir.5c00065","url":null,"abstract":"The study developed a thermoresponsive film to achieve autonomous fluid driving in microfluidic channels, simplify microfluidic systems, and improve their operability. This film has a lower critical solution temperature (LCST), exhibiting different wettabilities on each side of the LCST, and showed improved hydrophilicity-to-hydrophobicity conversion with increased substrate roughness, maintaining stability after repeated cycles. The thermoresponsive film was applied to the inner wall of the glass capillary, which showed a hydrophilic and enhanced capillary effect below the LCST and a hydrophobic and weakened capillary effect above the LCST. Subsequently, the modified capillary was placed under a dynamic temperature gradient, and the force analysis of the fluid in the flow channel was carried out. It was found that only when the driving force exceeded the axial resistance could the fluid migrate. Experimental analysis showed that fluid length was directly proportional to axial resistance and inversely proportional to both driving force and migration velocity at a constant dynamic temperature gradient. Additionally, the temperature of the hot end of the capillary was varied to form different dynamic temperature gradients. A higher dynamic temperature gradient resulted in greater fluid displacement and velocity at a constant fluid length. The results presented in this study were expected to provide new insights into the design and optimization of thermally driven microfluidic systems.","PeriodicalId":50,"journal":{"name":"Langmuir","volume":"27 1","pages":""},"PeriodicalIF":3.9,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143867154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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