Vaibhav Singh, Vajeeha Urunikulavan, Arun Kumar Bar
An insight on the fixation of CO2 gas into CO32- and concomitant formation of a novel series of carbonato dinuclear lanthanide(III) complexes is presented. The feature of inner coordination post-synthetic modification is demonstrated via ligand substitution at the terminally axial coordination sites of the dinuclear motifs.
{"title":"An insight en-route from CO2 fixation to CO32--bridged dinuclear lanthanide(III) complexes featuring inner coordination post-synthetic modification†","authors":"Vaibhav Singh, Vajeeha Urunikulavan, Arun Kumar Bar","doi":"10.1039/d4dt03050h","DOIUrl":"https://doi.org/10.1039/d4dt03050h","url":null,"abstract":"An insight on the fixation of CO2<small><sub></sub></small> gas into CO3<small><sub></sub></small>2-<small><sup></sup></small> and concomitant formation of a novel series of carbonato dinuclear lanthanide(III) complexes is presented. The feature of inner coordination post-synthetic modification is demonstrated via ligand substitution at the terminally axial coordination sites of the dinuclear motifs.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"56 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083803","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}
Designing of heterogeneous nanocatalyst comprising abundantly available transition metal for various organic transformations has captured significant interest in recent years due to its convenient separation, reusability and low metal contamination after the reaction. Herein, we report the design and synthesis of CuO@MnO2 nanocomposites using a malachite which is a renewable copper precursor with E-factor 1.64. The as prepared CuO@MnO2 nanocomposites were well characterized by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (pXRD), energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller techniques (BET). The catalytic efficiency of CuO@MnO2 nanocomposites was explored for the synthesis of 1,4-disubstituted 1,2,3-triazoles from phenyl acetylene, benzyl bromide and sodium azide under neat condition. The sustainability of present methodology was explored by evaluating the green chemistry metrices such as E-factor (0.84), reaction mass efficiency (54.45 %), process mass intensity (1.84) and turn over number (901).
{"title":"Design and development of copper-manganese oxide nanocatalyst for the sustainable synthesis of 1,4-disubstituted 1,2,3-triazoles","authors":"Manish Rawat, Nitish Kumar Sinha, Srishti Rawat, Kemant Pratap, Vandana Saraswat, Akash Kumar, Sahil Kohli","doi":"10.1039/d4dt02898h","DOIUrl":"https://doi.org/10.1039/d4dt02898h","url":null,"abstract":"Designing of heterogeneous nanocatalyst comprising abundantly available transition metal for various organic transformations has captured significant interest in recent years due to its convenient separation, reusability and low metal contamination after the reaction. Herein, we report the design and synthesis of CuO@MnO2 nanocomposites using a malachite which is a renewable copper precursor with E-factor 1.64. The as prepared CuO@MnO2 nanocomposites were well characterized by field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HR-TEM), powder X-ray diffraction (pXRD), energy-dispersive X-ray analysis (EDX), X-ray photoelectron spectroscopy (XPS), and Brunauer–Emmett–Teller techniques (BET). The catalytic efficiency of CuO@MnO2 nanocomposites was explored for the synthesis of 1,4-disubstituted 1,2,3-triazoles from phenyl acetylene, benzyl bromide and sodium azide under neat condition. The sustainability of present methodology was explored by evaluating the green chemistry metrices such as E-factor (0.84), reaction mass efficiency (54.45 %), process mass intensity (1.84) and turn over number (901).","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"38 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083812","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}
Yifan Xiao, Can Ma, Tangyou Sun, Qianju Song, Liang Bian, Zao Yi, Zhiqiang hao, Chaojun Tang, Pinghui Wu, Qingdong Zeng
This article employs a time-domain finite-difference (FDTD) approach to design an efficient solar energy capturing absorber consisting of high melting point metal (Ti), and semiconductor (GaAs). The structure generates cavity resonance (CR) and surface plasmon resonance (SPR), which achieves extremely high absorption in different wavelength bands. More than 90% absorption over a wide wavelength range (280-3000 nm) is exhibited by this structure. The structure achieves an average absorption efficiency of 97.0% in the wavelength range from 280 nm to 3000 nm at an air mass of 1.5 (AM 1.5). The structure shows insensitivity to the angle of incidence by maintaining a stable absorption of over 94% for changes in the angle of incidence from 0° to 60°. This structure can also work at 1400 K with thermal radiation efficiencies up to 98.2%. As the operating temperature rises from 600 K to 1400 K (with a temperature gradient of 200 K), the thermal radiation efficiency of the structure remains above 98% at all times. Based on the excellent radiation and absorption properties of this absorber, it owns a promising application in the field of solar energy absorption as well as thermal emission.
{"title":"Thermal radiation analysis of broadband solar energy capturing absorber using Ti and GaAs","authors":"Yifan Xiao, Can Ma, Tangyou Sun, Qianju Song, Liang Bian, Zao Yi, Zhiqiang hao, Chaojun Tang, Pinghui Wu, Qingdong Zeng","doi":"10.1039/d4dt03202k","DOIUrl":"https://doi.org/10.1039/d4dt03202k","url":null,"abstract":"This article employs a time-domain finite-difference (FDTD) approach to design an efficient solar energy capturing absorber consisting of high melting point metal (Ti), and semiconductor (GaAs). The structure generates cavity resonance (CR) and surface plasmon resonance (SPR), which achieves extremely high absorption in different wavelength bands. More than 90% absorption over a wide wavelength range (280-3000 nm) is exhibited by this structure. The structure achieves an average absorption efficiency of 97.0% in the wavelength range from 280 nm to 3000 nm at an air mass of 1.5 (AM 1.5). The structure shows insensitivity to the angle of incidence by maintaining a stable absorption of over 94% for changes in the angle of incidence from 0° to 60°. This structure can also work at 1400 K with thermal radiation efficiencies up to 98.2%. As the operating temperature rises from 600 K to 1400 K (with a temperature gradient of 200 K), the thermal radiation efficiency of the structure remains above 98% at all times. Based on the excellent radiation and absorption properties of this absorber, it owns a promising application in the field of solar energy absorption as well as thermal emission.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"207 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083813","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}
Alkaline water electrolysis despite being blessed with abundant and cheap non-noble metals-based anode catalysts, the cathodic hydrogen evolution reaction (HER) continues to be the pain even for the state-of-the-art Pt. In such proton-deficit environments, a metal hydroxide/oxide-based co-catalyst which can help polarizing the H–O bond in water has been found to promote the proton abstraction and subsequent reduction into H2 on Pt and Ru surfaces. Among them, the Ni(OH)2:Pt duo is one of the best. However, the relationship between the ratio of Ni(OH)2 and Pt and alkaline HER is not well-understood though it is essential for further advancements. Here, we report the results of a systematic study aimed at gradually increasing the Ni(OH)2:Pt ratio and studying their physical, chemical, and electrochemical properties which led us to strike the perfect balance between Ni(OH)2 and Pt. The optimised Ni(OH)2:Pt-3 with just 3.3 atom.% of Pt to Ni(OH)2 outperformed the commercial Pt/C (20 wt.%) by demanding just 9 and 50 mV for –10 and –100 mA cm–2, respectively and exhibiting faster kinetics with a very low Tafel slope of 40 mV dec–1, an impressive feat in a proton-deficient pH of 14. Thus, this study has now uncovered new knowledge on the role of the ratio of Ni(OH)2 and Pt in alkaline HER.
{"title":"Striking the Perfect Ni(OH)₂:Pt Balance for Boosted Electrocatalytic Water-Dissociation and H₂ Delivery in Proton-Deficient Environments","authors":"Roshini Arulraj, Tumpa Sadhukhan, Anantharaj Sengeni","doi":"10.1039/d4dt03232b","DOIUrl":"https://doi.org/10.1039/d4dt03232b","url":null,"abstract":"Alkaline water electrolysis despite being blessed with abundant and cheap non-noble metals-based anode catalysts, the cathodic hydrogen evolution reaction (HER) continues to be the pain even for the state-of-the-art Pt. In such proton-deficit environments, a metal hydroxide/oxide-based co-catalyst which can help polarizing the H–O bond in water has been found to promote the proton abstraction and subsequent reduction into H2 on Pt and Ru surfaces. Among them, the Ni(OH)2:Pt duo is one of the best. However, the relationship between the ratio of Ni(OH)2 and Pt and alkaline HER is not well-understood though it is essential for further advancements. Here, we report the results of a systematic study aimed at gradually increasing the Ni(OH)2:Pt ratio and studying their physical, chemical, and electrochemical properties which led us to strike the perfect balance between Ni(OH)2 and Pt. The optimised Ni(OH)2:Pt-3 with just 3.3 atom.% of Pt to Ni(OH)2 outperformed the commercial Pt/C (20 wt.%) by demanding just 9 and 50 mV for –10 and –100 mA cm–2, respectively and exhibiting faster kinetics with a very low Tafel slope of 40 mV dec–1, an impressive feat in a proton-deficient pH of 14. Thus, this study has now uncovered new knowledge on the role of the ratio of Ni(OH)2 and Pt in alkaline HER.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"8 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083801","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}
A set of ferrocene functionalized phenothiazine (PTZ) derivatives PTZ 1–3 were designed and synthesized by the Pd-catalyzed Buchwald−Hartwig cross-coupling reaction in good yields. PTZ 1–3 were treated with m-chloroperbenzoic acid (m-CPBA), which oxidize the sulfur (S) atom in the thiazine ring to sulfone, resulting in the ferrocene substituted phenothiazine sulfone derivatives PTZ 4–6. The influence of sulfur (S) oxidation state on the photophysical, redox properties, and thermal stability of the phenothiazine and phenothiazine sulfone derivatives were studied. The photophysical behaviour indicates that the phenothiazine sulfone derivatives PTZ 4–6 exhibit a hypsochromic shift in the UV-vis absorption as compared to PTZ 1–3. The ferrocene functionalized phenothiazine derivatives PTZ 1–3 exhibit better thermal stability than sulfone derivatives PTZ 4–6. The cyclic voltammetry studies on PTZ 1–6 show two oxidation waves. The density functional theory (DFT) and TD-DFT calculations were performed on PTZ 1–6 to analyze the molecular geometry, frontier molecular orbitals, molecular electrostatic potentials (MEP), and density of states (DOS). The influence of the ferrocene unit on the para, meta, and ortho position of the phenyl ring attached to the N-position of phenothiazine was investigated by spectroelectrochemical studies. The spectroscopic behavior of redox-active species of PTZ 1–3 shows a new and intense absorption band centred around 525 nm and two new red-shifted broad peaks centred at 750 and 850 in the NIR region. The structure of ferrocene functionalized phenothiazine and phenothiazine sulfone derivatives PTZ 1–6 was confirmed by single crystal X-ray diffraction. The photophysical and electrochemical properties of PTZ 1–6 offer valuable insights and potential applications in the development of redox-active materials, with significant contributions to the advancement of electronic and photonic technologies.
{"title":"Design, synthesis, and redox properties of ferrocene functionalized phenothiazine and phenothiazine sulfone isomers","authors":"Rajneesh Misra, Nikhil Tewari","doi":"10.1039/d4dt02821j","DOIUrl":"https://doi.org/10.1039/d4dt02821j","url":null,"abstract":"A set of ferrocene functionalized phenothiazine (PTZ) derivatives PTZ 1–3 were designed and synthesized by the Pd-catalyzed Buchwald−Hartwig cross-coupling reaction in good yields. PTZ 1–3 were treated with m-chloroperbenzoic acid (m-CPBA), which oxidize the sulfur (S) atom in the thiazine ring to sulfone, resulting in the ferrocene substituted phenothiazine sulfone derivatives PTZ 4–6. The influence of sulfur (S) oxidation state on the photophysical, redox properties, and thermal stability of the phenothiazine and phenothiazine sulfone derivatives were studied. The photophysical behaviour indicates that the phenothiazine sulfone derivatives PTZ 4–6 exhibit a hypsochromic shift in the UV-vis absorption as compared to PTZ 1–3. The ferrocene functionalized phenothiazine derivatives PTZ 1–3 exhibit better thermal stability than sulfone derivatives PTZ 4–6. The cyclic voltammetry studies on PTZ 1–6 show two oxidation waves. The density functional theory (DFT) and TD-DFT calculations were performed on PTZ 1–6 to analyze the molecular geometry, frontier molecular orbitals, molecular electrostatic potentials (MEP), and density of states (DOS). The influence of the ferrocene unit on the para, meta, and ortho position of the phenyl ring attached to the N-position of phenothiazine was investigated by spectroelectrochemical studies. The spectroscopic behavior of redox-active species of PTZ 1–3 shows a new and intense absorption band centred around 525 nm and two new red-shifted broad peaks centred at 750 and 850 in the NIR region. The structure of ferrocene functionalized phenothiazine and phenothiazine sulfone derivatives PTZ 1–6 was confirmed by single crystal X-ray diffraction. The photophysical and electrochemical properties of PTZ 1–6 offer valuable insights and potential applications in the development of redox-active materials, with significant contributions to the advancement of electronic and photonic technologies.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"39 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083821","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}
Koushik Saha, Basudeb Dutta, Pubali Das, Angeera Chandra, Arnab Samanta, Sudeep Ranjan Jana, Sudip Naskar, Rajat Saha, Partha Pratim Ray and Chittaranjan Sinha
Correction for ‘Structure-directing effect of terephthalate in bridging Zn(II)- and Cd(II)-based coordination polymers towards application in the detection of trace quantities of Pd2+ in aqueous media and their electrical conductivities’ by Koushik Saha et al., Dalton Trans., 2025, https://doi.org/10.1039/d4dt03075c.
{"title":"Correction: Structure-directing effect of terephthalate in bridging Zn(ii)- and Cd(ii)-based coordination polymers towards application in the detection of trace quantities of Pd2+ in aqueous media and their electrical conductivities","authors":"Koushik Saha, Basudeb Dutta, Pubali Das, Angeera Chandra, Arnab Samanta, Sudeep Ranjan Jana, Sudip Naskar, Rajat Saha, Partha Pratim Ray and Chittaranjan Sinha","doi":"10.1039/D5DT90031J","DOIUrl":"10.1039/D5DT90031J","url":null,"abstract":"<p >Correction for ‘Structure-directing effect of terephthalate in bridging Zn(<small>II</small>)- and Cd(<small>II</small>)-based coordination polymers towards application in the detection of trace quantities of Pd<small><sup>2+</sup></small> in aqueous media and their electrical conductivities’ by Koushik Saha <em>et al.</em>, <em>Dalton Trans.</em>, 2025, https://doi.org/10.1039/d4dt03075c.</p>","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":" 8","pages":" 3509-3509"},"PeriodicalIF":3.5,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/dt/d5dt90031j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Polyoxometalates (POMs) are discrete, anionic metal-oxo clusters of early transition metals in high oxidation states (e.g., WVI, MoVI, VV) usually comprised of edge- and corner-shared MO6 octahedra. Lacunary POMs are defect heteropolyanions mainly of the Keggin or Dawson type, and they can be formed by the loss of one or more MO6 octahedra by controlled base hydrolysis. The largest subclass of POMs are tungstophosphates, and several lacunary derivatives are known, such as the Keggin-based [PW11O39]7- and [PW9O34]9-, and the Dawson-based [P2W17O61]10- and [P2W15O56]12-. This review is based on the cyclic 48-tungsto-8-phosphate [H7P8W48O184]33- (P8W48) as well as its smaller derivatives [H6P4W24O94]18- (P4W24), and [H2P2W12O48]12- (P2W12), with a focus on structural aspects, solution stability and reactivity. All three polyanions can be considered as inorganic multidentate O-donor ligands that coordinate with d, f or p-block metal ions. Here we provide a comprehensive overview of guest metal-containing derivatives of the P8W48 wheel, the P4W24 half-wheel and the P2W12 quarter wheel. The structures containing P2W12 as a building unit are presented in a sequence of increasing number of POM units in the resulting assembly. Transition metal-containing POMs have been of interest for decades due to their remarkable capability of forming novel and unexpected structures associated with interesting and relevant physicochemical properties (e.g., catalysis, magnetism, biomedicine, electrochemistry), and this also applies for derivatives containing P8W48, P4W24 and P2W12.
{"title":"The Cyclic 48-Tungsto-8-Phosphate [H7P8W48O184]33- Contant-Tézé Polyanion and Its Derivatives [H6P4W24O94]18- and [H2P2W12O48]12-: Structural Aspects And Reactivity","authors":"Sib Sankar Mal, Abhishek Banerjee, Ulrich Kortz","doi":"10.1039/d4dt03448a","DOIUrl":"https://doi.org/10.1039/d4dt03448a","url":null,"abstract":"Polyoxometalates (POMs) are discrete, anionic metal-oxo clusters of early transition metals in high oxidation states (e.g., WVI, MoVI, VV) usually comprised of edge- and corner-shared MO6 octahedra. Lacunary POMs are defect heteropolyanions mainly of the Keggin or Dawson type, and they can be formed by the loss of one or more MO6 octahedra by controlled base hydrolysis. The largest subclass of POMs are tungstophosphates, and several lacunary derivatives are known, such as the Keggin-based [PW11O39]7- and [PW9O34]9-, and the Dawson-based [P2W17O61]10- and [P2W15O56]12-. This review is based on the cyclic 48-tungsto-8-phosphate [H7P8W48O184]33- (P8W48) as well as its smaller derivatives [H6P4W24O94]18- (P4W24), and [H2P2W12O48]12- (P2W12), with a focus on structural aspects, solution stability and reactivity. All three polyanions can be considered as inorganic multidentate O-donor ligands that coordinate with d, f or p-block metal ions. Here we provide a comprehensive overview of guest metal-containing derivatives of the P8W48 wheel, the P4W24 half-wheel and the P2W12 quarter wheel. The structures containing P2W12 as a building unit are presented in a sequence of increasing number of POM units in the resulting assembly. Transition metal-containing POMs have been of interest for decades due to their remarkable capability of forming novel and unexpected structures associated with interesting and relevant physicochemical properties (e.g., catalysis, magnetism, biomedicine, electrochemistry), and this also applies for derivatives containing P8W48, P4W24 and P2W12.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"15 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083817","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}
Sharon Signorella, Micaela Bruno, Gianfranco Frattini, Claudia Palopoli, Diego Martín Moreno, Nora Pellegri, Verónica Andrea Daier, Sandra Signorella
Two copper(II) complexes, [Cu(salbn)] and [Cu(py2bn)(OAc)]ClO4, formed with the Schiff-base ligands 1,4-bis(salicylidenamino)butane (H2salbn) and 1,4-bis(pyridin-2-ylmethyleneamino)butane (py2bn), have been prepared and characterized in solid state and in solution, and their ability to catalyse the dismutation of O2•− has been evaluated in homogeneous medium and immobilized in a mesoporous matrix. The crystal structures show that [Cu(salbn)] possesses a distorted square-planar geometry, while [Cu(py2bn)(OAc)]ClO4 adopts a cis-distorted octahedral geometry. The two complexes experience structural changes in solution, and different spectroscopies were used to examine them. Moreover, their redox potentials are strongly affected by the solvent. In water, the complexes exist as [Cu(salbn)(H2O)] and [Cu(py2bn)(H2O)]2+ with Cu(II)/Cu(I) reduction potential at -361 mV and -229 mV, respectively, well different from redox potentials measured in acetonitrile. Although with a more unfavourable redox potential, [Cu(salbn)(H2O)] reacts with O2•− faster than [Cu(py2bn)(H2O)]2+, with catalytic rate constants of 3.3x107 and 2.9x107 M-1s-1, respectively, at pH = 7.8. Both complexes exhibit higher superoxide dismutase activity than the analogues with a shorter central alkyl chain. The observed catalytic rates essentially correlate with the ligand flexibility, rather than with the redox potential, which is also supported by the slower O2•− dismutation rate when the complexes are immobilized by encapsulation into the channels of well-ordered mesoporous SBA-15 silica where the pore modifies the complex structures and restraints the ligand rearrangement.
{"title":"The Relative Impact of Ligand Flexibility and Redox Potential on the Activity of Cu Superoxide Dismutase Mimics","authors":"Sharon Signorella, Micaela Bruno, Gianfranco Frattini, Claudia Palopoli, Diego Martín Moreno, Nora Pellegri, Verónica Andrea Daier, Sandra Signorella","doi":"10.1039/d4dt03403a","DOIUrl":"https://doi.org/10.1039/d4dt03403a","url":null,"abstract":"Two copper(II) complexes, [Cu(salbn)] and [Cu(py2bn)(OAc)]ClO4, formed with the Schiff-base ligands 1,4-bis(salicylidenamino)butane (H2salbn) and 1,4-bis(pyridin-2-ylmethyleneamino)butane (py2bn), have been prepared and characterized in solid state and in solution, and their ability to catalyse the dismutation of O2•− has been evaluated in homogeneous medium and immobilized in a mesoporous matrix. The crystal structures show that [Cu(salbn)] possesses a distorted square-planar geometry, while [Cu(py2bn)(OAc)]ClO4 adopts a cis-distorted octahedral geometry. The two complexes experience structural changes in solution, and different spectroscopies were used to examine them. Moreover, their redox potentials are strongly affected by the solvent. In water, the complexes exist as [Cu(salbn)(H2O)] and [Cu(py2bn)(H2O)]2+ with Cu(II)/Cu(I) reduction potential at -361 mV and -229 mV, respectively, well different from redox potentials measured in acetonitrile. Although with a more unfavourable redox potential, [Cu(salbn)(H2O)] reacts with O2•− faster than [Cu(py2bn)(H2O)]2+, with catalytic rate constants of 3.3x107 and 2.9x107 M-1s-1, respectively, at pH = 7.8. Both complexes exhibit higher superoxide dismutase activity than the analogues with a shorter central alkyl chain. The observed catalytic rates essentially correlate with the ligand flexibility, rather than with the redox potential, which is also supported by the slower O2•− dismutation rate when the complexes are immobilized by encapsulation into the channels of well-ordered mesoporous SBA-15 silica where the pore modifies the complex structures and restraints the ligand rearrangement.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"38 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071676","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}
Sophie Hameury, Laura Bousquet, Nathalie Saffon-Merceron, Antoine Baceiredo, David Madec, Eddy Maerten
In recent years, carbones have emerged as a new exciting class of carbon-based ligands. We report here a series of organometallic complexes demonstrating the versatility in coordination mode of phosphine/sulfoxide carbone 1. Indeed, 1 is able to chelate both early and late transition metals, in a mono- or bidentate fashion depending on the oxyphilic character of metal center thanks to the presence of the sulfoxide moiety. All complexes have been fully characterized by X-ray diffraction analysis and by NMR spectroscopy (except Hafnium complex because of its extreme insolubility). It is noteworthy that silver(I) and zirconium(IV) complexes are efficient transmetalating reagents toward copper(I) complexes.
{"title":"Phosphine/Sulfoxide-Carbone, a Ligand with a Flexible Bonding Mode for Early to Late Transition Metals","authors":"Sophie Hameury, Laura Bousquet, Nathalie Saffon-Merceron, Antoine Baceiredo, David Madec, Eddy Maerten","doi":"10.1039/d4dt03372h","DOIUrl":"https://doi.org/10.1039/d4dt03372h","url":null,"abstract":"In recent years, carbones have emerged as a new exciting class of carbon-based ligands. We report here a series of organometallic complexes demonstrating the versatility in coordination mode of phosphine/sulfoxide carbone 1. Indeed, 1 is able to chelate both early and late transition metals, in a mono- or bidentate fashion depending on the oxyphilic character of metal center thanks to the presence of the sulfoxide moiety. All complexes have been fully characterized by X-ray diffraction analysis and by NMR spectroscopy (except Hafnium complex because of its extreme insolubility). It is noteworthy that silver(I) and zirconium(IV) complexes are efficient transmetalating reagents toward copper(I) complexes.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"121 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143071675","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}
Traditional preparation of yttrium aluminum garnet (YAG) transparent ceramics involves several steps, including powder preparation, molding process and sintering at high temperature. Herein, a new and simple method was developed to prepare YAG transparent polycrystalline films directly through a novel interface reaction between sapphire and a Y2(OH)x(CO3)y(NO3)(6-x-2y)·nH2O film attached to the sapphire. The prepared YAG:5%Ce transparent polycrystalline film could be combined with a blue chip to obtain fluorescence-converted white LED, with a CCT of 6361 K and a CRI (Ra) of 73.3. Introducing 1%Pr into the YAG:5%Ce system increased the CRI (Ra) to 77.4. When these transparent polycrystalline films were combined with a blue light laser diode (LD), similar spectra were obtained under high power density (4.17 W mm-2) excitation. YAG:5%Ce films produced a white light CCT of 5471 K, LE of 165.1 lm W-1, and Ra of 62.9, while YAG:5%Ce,1%Pr films produced a CCT of 6311 K, LE of 146.5 lm W-1, and Ra increased to 69.7. This study provides a novel "powder-free" and "glue-free" synthesis strategy for preparing fluorescence-converted YAG:Ce,Pr transparent polycrystalline films, which not only overcomes the disadvantages of traditional transparent ceramic preparation methods, such as time consumption, energy consumption, and equipment dependence, but also avoids the problem of aging in traditional fluorescent conversion materials.
{"title":"Yttrium aluminum garnet fluorescent conversion films for solid-state lighting: interface reaction synthesis strategy and modulation of warm white light.","authors":"Haoxuan Zeng, Taihui Chen, Yongping Guo, Xiaoli Wu","doi":"10.1039/d4dt03316g","DOIUrl":"https://doi.org/10.1039/d4dt03316g","url":null,"abstract":"<p><p>Traditional preparation of yttrium aluminum garnet (YAG) transparent ceramics involves several steps, including powder preparation, molding process and sintering at high temperature. Herein, a new and simple method was developed to prepare YAG transparent polycrystalline films directly through a novel interface reaction between sapphire and a Y<sub>2</sub>(OH)<sub><i>x</i></sub>(CO<sub>3</sub>)<sub><i>y</i></sub>(NO<sub>3</sub>)<sub>(6-<i>x</i>-2<i>y</i>)</sub>·<i>n</i>H<sub>2</sub>O film attached to the sapphire. The prepared YAG:5%Ce transparent polycrystalline film could be combined with a blue chip to obtain fluorescence-converted white LED, with a CCT of 6361 K and a CRI (Ra) of 73.3. Introducing 1%Pr into the YAG:5%Ce system increased the CRI (Ra) to 77.4. When these transparent polycrystalline films were combined with a blue light laser diode (LD), similar spectra were obtained under high power density (4.17 W mm<sup>-2</sup>) excitation. YAG:5%Ce films produced a white light CCT of 5471 K, LE of 165.1 lm W<sup>-1</sup>, and Ra of 62.9, while YAG:5%Ce,1%Pr films produced a CCT of 6311 K, LE of 146.5 lm W<sup>-1</sup>, and Ra increased to 69.7. This study provides a novel \"powder-free\" and \"glue-free\" synthesis strategy for preparing fluorescence-converted YAG:Ce,Pr transparent polycrystalline films, which not only overcomes the disadvantages of traditional transparent ceramic preparation methods, such as time consumption, energy consumption, and equipment dependence, but also avoids the problem of aging in traditional fluorescent conversion materials.</p>","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":" ","pages":""},"PeriodicalIF":3.5,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143062144","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}
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