Bioethanol production from agricultural residues has emerged as an important process of biomass valorization. The production of acetaldehyde from bioethanol has also started gaining ground. Since Cu-based catalysts are well-known for their ability to catalyse ethanol dehydrogenation, we have used a defect-modulated Cu-based metal–organic framework (MOF), HKUST-1, for obtaining mechanistic insights into the process. Defect-modulation in the form of a missing linker creates an easily accessible dual-atom site which can simultaneously participate in catalysing the reaction. Although ethanol dehydrogenation to ethylene competes with acetaldehyde production over both the defective HKUST-1(H) and HKUST-1(OH) MOF nodes, acetaldehyde formation occurs selectively. However, HKUST-1(OH) could not be regenerated at the end of the acetaldehyde formation pathway; HKUST-1(OH) ultimately transformed to HKUST-1(H) at the end of the cycle. This led to the introduction of the term ‘catalyst transfiguration’ where the catalyst, although transfigured, retains its ability to catalyse the reaction. Since, the HKUST-1(H) MOF node has the ability to selectively transform ethanol to acetaldehyde, we can safely conclude that the use of HKUST-1(OH) will not cause acetaldehyde formation to come to a halt and the reaction can go on beyond the first catalytic cycle. Thus, both the defective MOF nodes can selectively transform ethanol to acetaldehyde.
{"title":"The role of defect-modulated HKUST-1 MOF nodes in non-oxidative ethanol dehydrogenation: an observed phenomenon of catalyst transfiguration","authors":"Anjali Ganai, Pranab Sarkar","doi":"10.1039/d4dt03300k","DOIUrl":"https://doi.org/10.1039/d4dt03300k","url":null,"abstract":"Bioethanol production from agricultural residues has emerged as an important process of biomass valorization. The production of acetaldehyde from bioethanol has also started gaining ground. Since Cu-based catalysts are well-known for their ability to catalyse ethanol dehydrogenation, we have used a defect-modulated Cu-based metal–organic framework (MOF), HKUST-1, for obtaining mechanistic insights into the process. Defect-modulation in the form of a missing linker creates an easily accessible dual-atom site which can simultaneously participate in catalysing the reaction. Although ethanol dehydrogenation to ethylene competes with acetaldehyde production over both the defective HKUST-1(H) and HKUST-1(OH) MOF nodes, acetaldehyde formation occurs selectively. However, HKUST-1(OH) could not be regenerated at the end of the acetaldehyde formation pathway; HKUST-1(OH) ultimately transformed to HKUST-1(H) at the end of the cycle. This led to the introduction of the term ‘catalyst transfiguration’ where the catalyst, although transfigured, retains its ability to catalyse the reaction. Since, the HKUST-1(H) MOF node has the ability to selectively transform ethanol to acetaldehyde, we can safely conclude that the use of HKUST-1(OH) will not cause acetaldehyde formation to come to a halt and the reaction can go on beyond the first catalytic cycle. Thus, both the defective MOF nodes can selectively transform ethanol to acetaldehyde.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"49 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143427000","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}
Thomas Scattolin, Enrico Cavarzerani, dario alessi, Vincenzo Canzonieri, Isabella Caligiuri, Nicola Demitri, Matteo Mauceri, Flavio Rizzolio, Giovanni Tonon, Fabiano Visentin, Gilles Gasser, Maria Dalla Pozza, Steven P Nolan, Eleonora Botter, Ombretta Repetto, Urska Kamensek, Simona Kranjc Brezar, Maja Cemazar, Stefano Palazzolo
High-Grade Serous Ovarian Cancer (HGSOC) is the most common and lethal subtype of ovarian cancer, known for its high aggressiveness and extensive genomic alterations. Typically diagnosed at an advanced stage, HGSOC presents formidable challenges in drug therapy. The limited efficacy of standard treatments, development of chemoresistance, scarcity of targeted therapies, and significant tumor heterogeneity render this disease incurable with current treatment options, highlighting the urgent need for novel therapeutic approaches to improve patient outcomes. In this study we report a straightforward and stereoselective synthetic route to novel Pd(II)-vinyl and -butadienyl complexes bearing a wide range of monodentate and bidentate ligands. Most of the synthesized complexes exhibited good to excellent in vitro anticancer activity against ovarian cancer cells. Particularly promising is the water-soluble complex bearing two PTA (1,3,5-triaza-7-phosphaadamantane) ligands and the Pd(II)-butadienyl fragment. This compound combines excellent cytotoxicity towards cancer cells with substantial inactivity towards non-cancerous ones. This derivative was selected for further studies on ex vivo tumor organoids and in vivo mouse models, which demonstrate its remarkable efficacy with surprisingly low collateral toxicity even at high dosages. Moreover, this class of compounds appears to operate through a ferroptotic mechanism, thus representing the first such example for an organopalladium compound.
{"title":"Unlocking the Potential of Organopalladium Complexes for High-Grade Serous Ovarian Cancer Therapy","authors":"Thomas Scattolin, Enrico Cavarzerani, dario alessi, Vincenzo Canzonieri, Isabella Caligiuri, Nicola Demitri, Matteo Mauceri, Flavio Rizzolio, Giovanni Tonon, Fabiano Visentin, Gilles Gasser, Maria Dalla Pozza, Steven P Nolan, Eleonora Botter, Ombretta Repetto, Urska Kamensek, Simona Kranjc Brezar, Maja Cemazar, Stefano Palazzolo","doi":"10.1039/d5dt00194c","DOIUrl":"https://doi.org/10.1039/d5dt00194c","url":null,"abstract":"High-Grade Serous Ovarian Cancer (HGSOC) is the most common and lethal subtype of ovarian cancer, known for its high aggressiveness and extensive genomic alterations. Typically diagnosed at an advanced stage, HGSOC presents formidable challenges in drug therapy. The limited efficacy of standard treatments, development of chemoresistance, scarcity of targeted therapies, and significant tumor heterogeneity render this disease incurable with current treatment options, highlighting the urgent need for novel therapeutic approaches to improve patient outcomes. In this study we report a straightforward and stereoselective synthetic route to novel Pd(II)-vinyl and -butadienyl complexes bearing a wide range of monodentate and bidentate ligands. Most of the synthesized complexes exhibited good to excellent in vitro anticancer activity against ovarian cancer cells. Particularly promising is the water-soluble complex bearing two PTA (1,3,5-triaza-7-phosphaadamantane) ligands and the Pd(II)-butadienyl fragment. This compound combines excellent cytotoxicity towards cancer cells with substantial inactivity towards non-cancerous ones. This derivative was selected for further studies on ex vivo tumor organoids and in vivo mouse models, which demonstrate its remarkable efficacy with surprisingly low collateral toxicity even at high dosages. Moreover, this class of compounds appears to operate through a ferroptotic mechanism, thus representing the first such example for an organopalladium compound.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"51 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418185","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}
Michael Teixeira, Benoit Louis, Stéphane A. Baudron
Deep eutectic solvents (DESs) based on the 1:2 combination of choline chloride with either urea or e-urea (2-imidazolinone) have been studied as media for the preparation of Ca(II) metal-organic frameworks (Ca-MOFs). In particular, the impact of the urea derivative on the secondary building unit (SBU) has been investigated by exploring the formation of Ca-MOFs with a series of ten di- and tetra-carboxylic acids, varying in length, steric hindrance and in the number and relative orientation of coordinating units. While several of these ligands have, to the best of our knowledge, not been previously reported to form Ca-MOFs, eleven new materials could be prepared and characterized by single-crystal and powder diffraction, elemental and thermogravimetric analyses as well as absorption and emission spectroscopies. The DES incorporating e-urea was found to be especially prone to the formation of crystalline materials. However, a recurrent one-dimensional SBU based on bridging carboxylate moieties and the carbonyl unit of e-urea was observed. Coordination of the solvent molecule is assisted by hydrogen bonding of the NH groups leading to a strongly stabilizing motif preventing these materials from thermal activation without loss of crystallinity.
{"title":"A blessing and a curse: impact of urea derivatives on the secondary building unit of Ca-MOFs prepared in deep eutectic solvents","authors":"Michael Teixeira, Benoit Louis, Stéphane A. Baudron","doi":"10.1039/d4dt03254c","DOIUrl":"https://doi.org/10.1039/d4dt03254c","url":null,"abstract":"Deep eutectic solvents (DESs) based on the 1:2 combination of choline chloride with either urea or e-urea (2-imidazolinone) have been studied as media for the preparation of Ca(II) metal-organic frameworks (Ca-MOFs). In particular, the impact of the urea derivative on the secondary building unit (SBU) has been investigated by exploring the formation of Ca-MOFs with a series of ten di- and tetra-carboxylic acids, varying in length, steric hindrance and in the number and relative orientation of coordinating units. While several of these ligands have, to the best of our knowledge, not been previously reported to form Ca-MOFs, eleven new materials could be prepared and characterized by single-crystal and powder diffraction, elemental and thermogravimetric analyses as well as absorption and emission spectroscopies. The DES incorporating e-urea was found to be especially prone to the formation of crystalline materials. However, a recurrent one-dimensional SBU based on bridging carboxylate moieties and the carbonyl unit of e-urea was observed. Coordination of the solvent molecule is assisted by hydrogen bonding of the NH groups leading to a strongly stabilizing motif preventing these materials from thermal activation without loss of crystallinity.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"106 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418186","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}
Kuo-Wei Huang, Lujain Alrais, Indranil Dutta, Amol Hengne, Priyanka Chakraborty, Edy Abou-Hamad, Shibo Xi, Mohammad Misbahur Rahman, Jia Zhang, Benjamin W J Chen, Jean-Marie Basset
The dehydrogenation of formic acid can provide an efficient pathway for hydrogen generation in the presence of a suitable catalyst. Homogeneous catalysts have been extensively studied and utilized for highly active and selective processes compared to conventional heterogeneous catalysis, which often shows a lower reactivity and selectivity. However, the latter is preferred for a practical application, considering easy separation and recyclability. By incorporating the homogeneous organometallic complex onto an appropriate support, the unique features of both catalysts can be combined and utilized effectively. Herein, we investigate the immobilization of iridium picolinamide complex (1) supported onto a 3D fibrous modified silica that demonstrates high accessibility. The support involves a tetracoordinate aluminum hydride site featuring strong Lewis acidic nature. A study of the interaction and coordination sites around the surface fragment was conducted via various techniques, including elemental analysis, FT-IR, solid-state NMR, XAS, and first-principles calculations, which provided informative data. We explored the use of solid additives in a solvent-free reaction medium and avoided utilizing volatile bases to achieve the process feasibility with a high TOF of 40,000 h-1.
{"title":"Picolinamide Iridium Catalyst Immobilized on Aluminum-Hydride Anchor for the Selective Dehydrogenation of Neat Formic Acid","authors":"Kuo-Wei Huang, Lujain Alrais, Indranil Dutta, Amol Hengne, Priyanka Chakraborty, Edy Abou-Hamad, Shibo Xi, Mohammad Misbahur Rahman, Jia Zhang, Benjamin W J Chen, Jean-Marie Basset","doi":"10.1039/d4dt03521f","DOIUrl":"https://doi.org/10.1039/d4dt03521f","url":null,"abstract":"The dehydrogenation of formic acid can provide an efficient pathway for hydrogen generation in the presence of a suitable catalyst. Homogeneous catalysts have been extensively studied and utilized for highly active and selective processes compared to conventional heterogeneous catalysis, which often shows a lower reactivity and selectivity. However, the latter is preferred for a practical application, considering easy separation and recyclability. By incorporating the homogeneous organometallic complex onto an appropriate support, the unique features of both catalysts can be combined and utilized effectively. Herein, we investigate the immobilization of iridium picolinamide complex (1) supported onto a 3D fibrous modified silica that demonstrates high accessibility. The support involves a tetracoordinate aluminum hydride site featuring strong Lewis acidic nature. A study of the interaction and coordination sites around the surface fragment was conducted via various techniques, including elemental analysis, FT-IR, solid-state NMR, XAS, and first-principles calculations, which provided informative data. We explored the use of solid additives in a solvent-free reaction medium and avoided utilizing volatile bases to achieve the process feasibility with a high TOF of 40,000 h-1.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"1 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418183","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}
Miguel A. Romero-Solano, Eya Caridad Rodríguez-Pupo, IGNACIO MARTINEZ MARTINEZ, Berenice Prestegui Martel, Alberto Martínez-Muñoz, Bertha Espinoza, Diego Martínez-Otero, Víctor López-Guerrero, Alma Esteban-Covarrubias, Alejandro Dorazco-González
The development of new biometal-based complexes containing antiparasitic bioactive ligands is a central field of coordination chemistry that impacts bioinorganic, medicinal, and biological chemistry. Herein, two novel water-soluble polynuclear Cu(II)-complexes with formula [Cu<small><sub>4</sub></small>(4,4’-dmbp)<small><sub>4</sub></small>(μ<small><sub>3</sub></small>-HRis)<small><sub>2</sub></small>Cl<small><sub>2</sub></small>], <strong>1</strong> and [Cu<small><sub>2</sub></small>(5,5´-dmbp)<small><sub>2</sub></small>(µ<small><sub>2</sub></small>-HRis)(H2<small><sub></sub></small>O)Cl] <strong>2</strong>, (4,4’-dmbp= 4,4’-dimethyl-2,2’-bipyridine, 5,5’-dmbp= 5,5’-dimethyl-2,2’-bipyridine, HRis= risedronate), were synthesized by self-assembly solution reactions between the corresponding precursor complexes [Cu<small><sub>2</sub></small>(dmbp)Cl<small><sub>2</sub></small>] and the drug Na<small><sub>2</sub></small>Ris in aqueous media. Both Cu(II)-Ris complexes <strong>1</strong>-2 were structurally described by single-crystal X-ray diffraction, characterized by spectroscopic tools (IR-ATR, HRMS, UV-Vis, EPR) and studied as antiparasitic agents against <em>Trypanosoma cruzi </em>causative agent of Chagas disease and <em>Leishmania mexicana</em> that is the etiological agent of cutaneous Leishmaniasis. X-ray structural analysis reveals that <strong>1</strong> is an uncommon tetranuclear Cu<small><sub>4</sub></small> complex where four crystallographically independent units [Cu(4,4’dmbp)]<small><sup>2+</sup></small> are double-bridged coordinated by two tetra-deprotonated ligands HRis containing the protonated pyridine ring. All Cu(II) centers show a distorted square-based pyramid geometry, and they are coordinated by two bisphosphonate fragments from HRis in a coordination environment μ<small><sub>3</sub></small> for each one. Crystal analysis of <strong>2</strong> displays a dinuclear Cu<small><sub>2</sub></small> complex where one ligand HRis coordinated to two different units [Cu(4,4’dmb)]<small><sup>2+</sup></small> in a μ<small><sub>2 </sub></small>mode, both Cu(II) present distorted square-based pyramid geometry. In general, complexes <strong>1</strong>-<strong>2</strong> are hydrostable in the millimolar concentration range and present low citotoxicity (< 22 % on the growth of cancer cell lines and healthy COS-7 cells) similar to the commercial drug, monosodium salt of risedronic acid (NaRis) Complexes <strong>1</strong>-<strong>2</strong> and NaRis were evaluated in vitro against <em>T. cruzi</em> epimastigotes and <em>L. mexicana</em> promastigotes. Results demonstrated that these Cu-Ris complexes improved the percentages of growth inhibition for <em>T. cruzi</em>. This inhibition ranged from 62-70% at concentrations of 5.0 mM after 24 h and 48 h incubation, compared to those observed for free, which has an inhibition of ~38%. Under the same concentration at 24 h incubation, complex <strong>1</strong> has a significantly greater inhi
{"title":"Tetranuclear and Dinuclear Cu(II) Complexes with Risedronate as anti-Trypanosoma cruzi and anti-Leishmania mexicana Agents. Synthesis, Crystal Structures, and Biological Evaluation.","authors":"Miguel A. Romero-Solano, Eya Caridad Rodríguez-Pupo, IGNACIO MARTINEZ MARTINEZ, Berenice Prestegui Martel, Alberto Martínez-Muñoz, Bertha Espinoza, Diego Martínez-Otero, Víctor López-Guerrero, Alma Esteban-Covarrubias, Alejandro Dorazco-González","doi":"10.1039/d4dt03516j","DOIUrl":"https://doi.org/10.1039/d4dt03516j","url":null,"abstract":"The development of new biometal-based complexes containing antiparasitic bioactive ligands is a central field of coordination chemistry that impacts bioinorganic, medicinal, and biological chemistry. Herein, two novel water-soluble polynuclear Cu(II)-complexes with formula [Cu<small><sub>4</sub></small>(4,4’-dmbp)<small><sub>4</sub></small>(μ<small><sub>3</sub></small>-HRis)<small><sub>2</sub></small>Cl<small><sub>2</sub></small>], <strong>1</strong> and [Cu<small><sub>2</sub></small>(5,5´-dmbp)<small><sub>2</sub></small>(µ<small><sub>2</sub></small>-HRis)(H2<small><sub></sub></small>O)Cl] <strong>2</strong>, (4,4’-dmbp= 4,4’-dimethyl-2,2’-bipyridine, 5,5’-dmbp= 5,5’-dimethyl-2,2’-bipyridine, HRis= risedronate), were synthesized by self-assembly solution reactions between the corresponding precursor complexes [Cu<small><sub>2</sub></small>(dmbp)Cl<small><sub>2</sub></small>] and the drug Na<small><sub>2</sub></small>Ris in aqueous media. Both Cu(II)-Ris complexes <strong>1</strong>-2 were structurally described by single-crystal X-ray diffraction, characterized by spectroscopic tools (IR-ATR, HRMS, UV-Vis, EPR) and studied as antiparasitic agents against <em>Trypanosoma cruzi </em>causative agent of Chagas disease and <em>Leishmania mexicana</em> that is the etiological agent of cutaneous Leishmaniasis. X-ray structural analysis reveals that <strong>1</strong> is an uncommon tetranuclear Cu<small><sub>4</sub></small> complex where four crystallographically independent units [Cu(4,4’dmbp)]<small><sup>2+</sup></small> are double-bridged coordinated by two tetra-deprotonated ligands HRis containing the protonated pyridine ring. All Cu(II) centers show a distorted square-based pyramid geometry, and they are coordinated by two bisphosphonate fragments from HRis in a coordination environment μ<small><sub>3</sub></small> for each one. Crystal analysis of <strong>2</strong> displays a dinuclear Cu<small><sub>2</sub></small> complex where one ligand HRis coordinated to two different units [Cu(4,4’dmb)]<small><sup>2+</sup></small> in a μ<small><sub>2 </sub></small>mode, both Cu(II) present distorted square-based pyramid geometry. In general, complexes <strong>1</strong>-<strong>2</strong> are hydrostable in the millimolar concentration range and present low citotoxicity (< 22 % on the growth of cancer cell lines and healthy COS-7 cells) similar to the commercial drug, monosodium salt of risedronic acid (NaRis) Complexes <strong>1</strong>-<strong>2</strong> and NaRis were evaluated in vitro against <em>T. cruzi</em> epimastigotes and <em>L. mexicana</em> promastigotes. Results demonstrated that these Cu-Ris complexes improved the percentages of growth inhibition for <em>T. cruzi</em>. This inhibition ranged from 62-70% at concentrations of 5.0 mM after 24 h and 48 h incubation, compared to those observed for free, which has an inhibition of ~38%. Under the same concentration at 24 h incubation, complex <strong>1</strong> has a significantly greater inhi","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"48 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418184","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}
Electrocatalytic carbon dioxide reduction (eCO2R) represents a sustainable technology for converting CO2 into valuable chemicals and fuels. Metal-organic frameworks (MOFs) material is recognized as a promising candidate in eCO2R due to its favorable adsorption of CO2. However, the insufficiency of adequate active sites restricts its in-depth investigation. Herein, inspired by the interfacial electronic effects, the layered g-C3N4 with unpaired electron characteristics is integrated into Cu-Zn-MOFs with nucleophilic imidazolate ligands via electrostatic assembly. The resultant g-C3N4@Cu-Zn-MOFs-1:1 exhibits excellent CO2 reduction performance for CO at a wide potential range, where the peak Faradaic efficiency reaches 85% at -1.3 V. The g-C3N4 with graphitic carbon backbone significantly stabilizes Cu-Zn-MOFs structure and enhances the exposure of active sites. The excellent performance stems from the significant activation of active sites by the efficient electron transfer induced by π-π stacking interactions between g-C3N4 and Cu-Zn-MOFs-1:1. This work proposes an innovative approach to stabilizing MOFs and activating the active sites in MOFs through interfacial electron engineering for CO2 reduction.
{"title":"Synergistic interaction between g-C3N4 and Cu-Zn-MOFs via electrostatic assembly for enhanced electrocatalytic CO2 reduction","authors":"Xiaoqing Lu, Zhaolong Yue, Hongyu Chen, Siyuan Liu, Shuxian Wei, Zhaojie Wang","doi":"10.1039/d4dt03554b","DOIUrl":"https://doi.org/10.1039/d4dt03554b","url":null,"abstract":"Electrocatalytic carbon dioxide reduction (eCO2R) represents a sustainable technology for converting CO2 into valuable chemicals and fuels. Metal-organic frameworks (MOFs) material is recognized as a promising candidate in eCO2R due to its favorable adsorption of CO2. However, the insufficiency of adequate active sites restricts its in-depth investigation. Herein, inspired by the interfacial electronic effects, the layered g-C3N4 with unpaired electron characteristics is integrated into Cu-Zn-MOFs with nucleophilic imidazolate ligands via electrostatic assembly. The resultant g-C3N4@Cu-Zn-MOFs-1:1 exhibits excellent CO2 reduction performance for CO at a wide potential range, where the peak Faradaic efficiency reaches 85% at -1.3 V. The g-C3N4 with graphitic carbon backbone significantly stabilizes Cu-Zn-MOFs structure and enhances the exposure of active sites. The excellent performance stems from the significant activation of active sites by the efficient electron transfer induced by π-π stacking interactions between g-C3N4 and Cu-Zn-MOFs-1:1. This work proposes an innovative approach to stabilizing MOFs and activating the active sites in MOFs through interfacial electron engineering for CO2 reduction.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"80 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418187","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}
Tz-Ching Tsui, Hao-Yuan Lan, Han-Jung Li, Ting-Shen Kuo, Hsueh-Ju Liu
This study investigates the design, synthesis, and reactivity of bidentate aluminum Lewis acids supported by amido and cyclopentadienyl donor sets within a flexible 1,4-disubstituted phenylene framework. The reactivity of these complexes with nitrogen-based ditopic donors was systematically explored, revealing their capacity to form host-guest assemblies. Reactions with pyrazine or quinoxaline yielded 1:1 adducts, while the reaction with 4,4’-bipyridine, which features a longer N∙∙∙N distance, resulted in a dimeric 2:2 adduct. In contrast, sterically demanding nitrogen donors such as 2,3,5,6-tetramethylpyrazine or phenazine showed no reactivity with these bidentate Lewis acids. The results reveal not only the robust Lewis acidic nature of the aluminum centers but also the pivotal role of ligand flexibility in facilitating diverse molecular interactions.
{"title":"Flexible Bidentate Aluminum Lewis Acids for Host–Guest Complex Formation","authors":"Tz-Ching Tsui, Hao-Yuan Lan, Han-Jung Li, Ting-Shen Kuo, Hsueh-Ju Liu","doi":"10.1039/d4dt03288h","DOIUrl":"https://doi.org/10.1039/d4dt03288h","url":null,"abstract":"This study investigates the design, synthesis, and reactivity of bidentate aluminum Lewis acids supported by amido and cyclopentadienyl donor sets within a flexible 1,4-disubstituted phenylene framework. The reactivity of these complexes with nitrogen-based ditopic donors was systematically explored, revealing their capacity to form host-guest assemblies. Reactions with pyrazine or quinoxaline yielded 1:1 adducts, while the reaction with 4,4’-bipyridine, which features a longer N∙∙∙N distance, resulted in a dimeric 2:2 adduct. In contrast, sterically demanding nitrogen donors such as 2,3,5,6-tetramethylpyrazine or phenazine showed no reactivity with these bidentate Lewis acids. The results reveal not only the robust Lewis acidic nature of the aluminum centers but also the pivotal role of ligand flexibility in facilitating diverse molecular interactions.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"77 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401944","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}
Jia-Rong Jiang, Yu-Jie Zhu, Wei-Nan Li, Yang Zhou, Hui-Sheng Wang
Although design of the containing Dy(III) single molecule magnets (SMMs) based on electrostatic potential has been employed for several years, the reasonable studies on the correlations between the electrostatic potential of single DyIII ion and its energy barriers was not reported previously. In this work, a novel “Y”-shaped MnIII5DyIII3 complex, [MnIII5DyIII3(NO3)(OCH3)(L)4(L')2(tea)(teaH)4]OH·3CH3OH·2H2O (1, H2L = 2-methoxy-6-[(Z)-(1H-1,2,4-triazol-3-ylimino)methyl]phenol, H3tea = triethanolamine and HL'= 2-hydroxy-3-methoxybenzaldehyde) was obtained by the reaction of H2L ligand, teaH3, Dy(NO3)3·6H2O and MnCl2·4H2O in CH3OH and DMF. Structural analysis revealed that the coordination geometry of Dy1 in 1 is muffin (MFF-9, Cs), while the geometries of Dy2 and Dy3 are located among spherical capped square antiprism (CSAPR-9, C4v), spherical tricapped trigonal prism (TCTPR-9, D3h) and muffin (MFF-9, Cs). Magnetic studies indicated that 1 exhibits slow magnetic relaxation behavior under a zero dc field. More importantly, we first proposed two parameters Req and Rax to describe the relationship. The two parameters were employed for three DyIII in 1, and one Zn2Dy complex as well as one mononuclear Dy complex reported by others. The results indicate that the calculated energy barrier (Ucal) continuously increase upon decreasing the Rax absolute values. However, the Rax absolute values are larger, the Ucal are smaller. This indicates that when the electrostatic potentials from two sides of the equatorial plane of DyIII are completely equivalent with each other, the Ucal is the largest. Moreover, POLY_ANISO and DFT calculations for 1 indicated that except for J4 showing ferromagnetic coupling, all magnetic couplings are antiferromagnetic, which were interpreted by the magneto-structural correlation.
{"title":"Semiquantitative Studies on the Correlations Between the Electrostatic Potential of Single DyIII Ion and its Energy Barriers in the Containing Dy Single Molecule Magnets†","authors":"Jia-Rong Jiang, Yu-Jie Zhu, Wei-Nan Li, Yang Zhou, Hui-Sheng Wang","doi":"10.1039/d5dt00017c","DOIUrl":"https://doi.org/10.1039/d5dt00017c","url":null,"abstract":"Although design of the containing Dy(III) single molecule magnets (SMMs) based on electrostatic potential has been employed for several years, the reasonable studies on the correlations between the electrostatic potential of single DyIII ion and its energy barriers was not reported previously. In this work, a novel “Y”-shaped MnIII5DyIII3 complex, [MnIII5DyIII3(NO3)(OCH3)(L)4(L')2(tea)(teaH)4]OH·3CH3OH·2H2O (1, H2L = 2-methoxy-6-[(Z)-(1H-1,2,4-triazol-3-ylimino)methyl]phenol, H3tea = triethanolamine and HL'= 2-hydroxy-3-methoxybenzaldehyde) was obtained by the reaction of H2L ligand, teaH3, Dy(NO3)3·6H2O and MnCl2·4H2O in CH3OH and DMF. Structural analysis revealed that the coordination geometry of Dy1 in 1 is muffin (MFF-9, Cs), while the geometries of Dy2 and Dy3 are located among spherical capped square antiprism (CSAPR-9, C4v), spherical tricapped trigonal prism (TCTPR-9, D3h) and muffin (MFF-9, Cs). Magnetic studies indicated that 1 exhibits slow magnetic relaxation behavior under a zero dc field. More importantly, we first proposed two parameters Req and Rax to describe the relationship. The two parameters were employed for three DyIII in 1, and one Zn2Dy complex as well as one mononuclear Dy complex reported by others. The results indicate that the calculated energy barrier (Ucal) continuously increase upon decreasing the Rax absolute values. However, the Rax absolute values are larger, the Ucal are smaller. This indicates that when the electrostatic potentials from two sides of the equatorial plane of DyIII are completely equivalent with each other, the Ucal is the largest. Moreover, POLY_ANISO and DFT calculations for 1 indicated that except for J4 showing ferromagnetic coupling, all magnetic couplings are antiferromagnetic, which were interpreted by the magneto-structural correlation.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"2 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401946","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}
Thomais G. Tziotzi, Eleftheria Agapaki, Emmanouil Κ. Charkiolakis, David Gracia, Marc Ubach, Scott Dalgarno, Marco Evangelisti, Euan K. Brechin, Constantinos J Milios
The solvothermal reaction of NiCl2.6H2O with 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane, LH3, and Ln(OAc)3.4H2O in the presence of salicylaldehyde in MeOH leads to the formation of the dodecanuclear isostructural species [NiII8Ln4(L’)8(OAc)4(OH)8(H2O)4].xH2O (Ln= Dy, x=6 (1); Gd, x= 24 (2); Y, x= 10 (3); L’ = the dianion of the Schiff-base resulting from the reaction of salicylaldehyde and ethanolamine). The metallic core of the clusters describes a ring a of corner-sharing {Ni2Ln2} cubanes assembled on a central, planar rectangular {Ln4} unit. Magnetization studies conducted on complexes 1 - 3 demonstrate the presence of dominant ferromagnetic exchanges at low temperatures, which is largely attributed to the Ni⋯Ni interactions. The significant magnetocaloric effect observed in the Gd analogue has been assessed through heat-capacity and magnetization measurements.
{"title":"Dodecanuclear [NiII8Ln4] clusters and rings of corner-sharing {NiII2Ln2} cubanes (Ln = Dy, Gd, Y}; Magnetic and Magnetothermal properties","authors":"Thomais G. Tziotzi, Eleftheria Agapaki, Emmanouil Κ. Charkiolakis, David Gracia, Marc Ubach, Scott Dalgarno, Marco Evangelisti, Euan K. Brechin, Constantinos J Milios","doi":"10.1039/d5dt00175g","DOIUrl":"https://doi.org/10.1039/d5dt00175g","url":null,"abstract":"The solvothermal reaction of NiCl2.6H2O with 1,3,5-tri(2-hydroxyethyl)-1,3,5-triazacyclohexane, LH3, and Ln(OAc)3.4H2O in the presence of salicylaldehyde in MeOH leads to the formation of the dodecanuclear isostructural species [NiII8Ln4(L’)8(OAc)4(OH)8(H2O)4].xH2O (Ln= Dy, x=6 (1); Gd, x= 24 (2); Y, x= 10 (3); L’ = the dianion of the Schiff-base resulting from the reaction of salicylaldehyde and ethanolamine). The metallic core of the clusters describes a ring a of corner-sharing {Ni2Ln2} cubanes assembled on a central, planar rectangular {Ln4} unit. Magnetization studies conducted on complexes 1 - 3 demonstrate the presence of dominant ferromagnetic exchanges at low temperatures, which is largely attributed to the Ni⋯Ni interactions. The significant magnetocaloric effect observed in the Gd analogue has been assessed through heat-capacity and magnetization measurements.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"63 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143401947","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}
Ninian John Blackburn, Evan F Welch, Katherine W Rush, Karsten A. S. Eastman, Vahe Bandarian
Bioactive peptides generally require post-translational processing to convert them to their fully active forms. Peptidylglycine monooxygenase (PHM) is a copper-dependent enzyme that catalyzes C-alpha hydroxylation of a glycine-extended pro-peptide, a critical post-translational step in peptide amidation. A canonical mechanism based on experimental and theoretical considerations proposes that molecular oxygen reacts at the mononuclear CuM-center to form a reactive Cu(II)-superoxo intermediate capable of H-atom abstraction from the peptidyl substrate, followed by long range ET from the CuH center positioned 11 Å away across a solvent-filled cleft. However, recent data has challenged this mechanism, suggesting instead that an “open-to-closed” conformational transition brings the copper centers closer to facilitate reaction at a binuclear copper site. Here we present direct observations of an enzyme-bound binuclear copper species, which was enabled by the use of an Ala-Ala-Phe-homoselenocysteine (hSeCys) species. EXAFS, UV/vis, and EPR studies are used to show that this reagent reacts with the oxidized enzyme to form a novel mixed valence entity which is subtly different from that observed previously for the S-peptidyl complex (J. Am. Chem. Soc. (2024)146, 5074-5080). In the ascorbate-reduced Cu(I) state of PHM, EXAFS measurements at both the Se and Cu absorption edges provide a unique signature of a bridging mode of binding, with Se-Cu site occupancy (1.8) measured from the Se-EXAFS simulating to twice that of the Cu-Se site occupancy (0.85) measured at the Cu edge. The ability of the hSeCys entity to induce a binuclear state is further emphasized by the XAS of the selenomethionyl peptide complex, where no such bridging chemistry is observed. The properties of the binuclear PHM derivative are of interest due to their unique chemical signatures, as well as providing the basis for a completely new mechanistic paradigm for PHM and its monooxygenase congeners.
{"title":"The Binuclear Copper State of Peptidylglycine Monooxygenase Visualized through a Selenium-Substituted Peptidyl-Homocysteine Complex","authors":"Ninian John Blackburn, Evan F Welch, Katherine W Rush, Karsten A. S. Eastman, Vahe Bandarian","doi":"10.1039/d5dt00082c","DOIUrl":"https://doi.org/10.1039/d5dt00082c","url":null,"abstract":"Bioactive peptides generally require post-translational processing to convert them to their fully active forms. Peptidylglycine monooxygenase (PHM) is a copper-dependent enzyme that catalyzes C-alpha hydroxylation of a glycine-extended pro-peptide, a critical post-translational step in peptide amidation. A canonical mechanism based on experimental and theoretical considerations proposes that molecular oxygen reacts at the mononuclear CuM-center to form a reactive Cu(II)-superoxo intermediate capable of H-atom abstraction from the peptidyl substrate, followed by long range ET from the CuH center positioned 11 Å away across a solvent-filled cleft. However, recent data has challenged this mechanism, suggesting instead that an “open-to-closed” conformational transition brings the copper centers closer to facilitate reaction at a binuclear copper site. Here we present direct observations of an enzyme-bound binuclear copper species, which was enabled by the use of an Ala-Ala-Phe-homoselenocysteine (hSeCys) species. EXAFS, UV/vis, and EPR studies are used to show that this reagent reacts with the oxidized enzyme to form a novel mixed valence entity which is subtly different from that observed previously for the S-peptidyl complex (J. Am. Chem. Soc. (2024)146, 5074-5080). In the ascorbate-reduced Cu(I) state of PHM, EXAFS measurements at both the Se and Cu absorption edges provide a unique signature of a bridging mode of binding, with Se-Cu site occupancy (1.8) measured from the Se-EXAFS simulating to twice that of the Cu-Se site occupancy (0.85) measured at the Cu edge. The ability of the hSeCys entity to induce a binuclear state is further emphasized by the XAS of the selenomethionyl peptide complex, where no such bridging chemistry is observed. The properties of the binuclear PHM derivative are of interest due to their unique chemical signatures, as well as providing the basis for a completely new mechanistic paradigm for PHM and its monooxygenase congeners.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"35 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143418188","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：