Jiejun Ren, Shihui Zhou, Pu Hu, Peng Meng, Zhanhui Zhang
Light-emitting diodes are considered the next-generation lighting technology due to their high efficiency, reliability, and energy savings. However, single-phase color-tunable phosphors with excellent luminous properties are still urgently needed. Herein, series of Tb3+/Eu3+ co-doped Ba2ZnGe2O7 phosphors were synthesized via a high-temperature solid-state reaction. The crystal structure, chemical composition, photoluminescence properties, and energy transfer process of the obtained phosphors were deeply investigated. To optimize the luminous efficiency of the phosphors, alkali metal ions were doped into the phosphors to provide charge compensation, leading to a significant enhancement in photoluminescence intensity. By modulating the Tb3+/Eu3+ ratio, the emission color of the Tb3+/Eu3+ co-doped Ba2ZnGe2O7 phosphors could be easily tuned from green to red. The efficient Tb3+ → Eu3+ energy transfer in Ba2ZnGe2O7 phosphors was determined to be a quadrupole-quadrupole interaction. The color-tunable Ba2ZnGe2O7:Tb3+,Eu3+ phosphors exhibited excellent optical properties and thermal stability, demonstrating great potential for applications in the next generation of lighting technology.
{"title":"Energy transfer and charge compensation of Ba2ZnGe2O7:Tb3+,Eu3+ phosphors for white LEDs","authors":"Jiejun Ren, Shihui Zhou, Pu Hu, Peng Meng, Zhanhui Zhang","doi":"10.1039/d4dt03535f","DOIUrl":"https://doi.org/10.1039/d4dt03535f","url":null,"abstract":"Light-emitting diodes are considered the next-generation lighting technology due to their high efficiency, reliability, and energy savings. However, single-phase color-tunable phosphors with excellent luminous properties are still urgently needed. Herein, series of Tb<small><sup>3+</sup></small>/Eu<small><sup>3+</sup></small> co-doped Ba<small><sub>2</sub></small>ZnGe<small><sub>2</sub></small>O<small><sub>7</sub></small> phosphors were synthesized <em>via</em> a high-temperature solid-state reaction. The crystal structure, chemical composition, photoluminescence properties, and energy transfer process of the obtained phosphors were deeply investigated. To optimize the luminous efficiency of the phosphors, alkali metal ions were doped into the phosphors to provide charge compensation, leading to a significant enhancement in photoluminescence intensity. By modulating the Tb<small><sup>3+</sup></small>/Eu<small><sup>3+</sup></small> ratio, the emission color of the Tb<small><sup>3+</sup></small>/Eu<small><sup>3+</sup></small> co-doped Ba<small><sub>2</sub></small>ZnGe<small><sub>2</sub></small>O<small><sub>7</sub></small> phosphors could be easily tuned from green to red. The efficient Tb<small><sup>3+</sup></small> → Eu<small><sup>3+</sup></small> energy transfer in Ba<small><sub>2</sub></small>ZnGe<small><sub>2</sub></small>O<small><sub>7</sub></small> phosphors was determined to be a quadrupole-quadrupole interaction. The color-tunable Ba<small><sub>2</sub></small>ZnGe<small><sub>2</sub></small>O<small><sub>7</sub></small>:Tb<small><sup>3+</sup></small>,Eu<small><sup>3+</sup></small> phosphors exhibited excellent optical properties and thermal stability, demonstrating great potential for applications in the next generation of lighting technology.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"62 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143192619","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}
Abhishek Panwar, Chandi Charan Malakar, Aarti Upadhyay, Mithun Roy
We developed a novel red light activable hetero-bimetallic [Fe(III)-Ru(II)] complex by combining hydroxyl radical-generating Fe(III)-catecholate as type I PDT and singlet oxygen generating Ru(II)-paracymene complex as type II PDT agents and potentially function as a dual modality PDT tool for enhanced phototherapeutic applications. The bridging linker 2-amino-3-(3,4-dihydroxyphenyl)-N-(1,10-phenanthrolin-5-yl)propenamide (L2) acted as bridging linker. The single pot synthesis of hetero-bimetallic [Fe(III)-Ru(II)] complex was carried out through acid-amine coupling. Various photophysical assays confirmed the photo-activated production of (●OH) radicals and (1O2) oxygen generation upon activation of the [Fe(III)-Ru(II)] complex by red light (600-720 nm, 30 J cm-2), and resulted in enhanced cytotoxicity with photo-index ~45. The complex, [Fe(III)-Ru(II)] potentially bonded to the DNA binding by ruthenium moiety was responsible for minimal dark toxicity. The cytotoxic potential of the complex under red light was a result of the photo-induced accumulation of reactive oxygen species through both type I and type II photodynamic therapy (PDT) mechanisms in A549 and HeLa cells, while non-cancerous HPL1D cells remained unaffected. We probed the caspase 3/7-dependent apoptosis of the complex, [Fe(III)-Ru(II)], in vitro. Overall, the hetero-bimetallic [Fe(III)-Ru(II)] complex offered an ideal example of a red light activable dual-modality next-generation PDT tool for phototherapeutic anticancer therapy.
{"title":"A red light-activable hetero-bimetallic [Fe(III)-Ru(II)] complex as a dual-modality PDT tool for anticancer therapy","authors":"Abhishek Panwar, Chandi Charan Malakar, Aarti Upadhyay, Mithun Roy","doi":"10.1039/d4dt03433c","DOIUrl":"https://doi.org/10.1039/d4dt03433c","url":null,"abstract":"We developed a novel red light activable hetero-bimetallic [Fe(III)-Ru(II)] complex by combining hydroxyl radical-generating Fe(III)-catecholate as type I PDT and singlet oxygen generating Ru(II)-paracymene complex as type II PDT agents and potentially function as a dual modality PDT tool for enhanced phototherapeutic applications. The bridging linker 2-amino-3-(3,4-dihydroxyphenyl)-N-(1,10-phenanthrolin-5-yl)propenamide (L2) acted as bridging linker. The single pot synthesis of hetero-bimetallic [Fe(III)-Ru(II)] complex was carried out through acid-amine coupling. Various photophysical assays confirmed the photo-activated production of (●OH) radicals and (1O2) oxygen generation upon activation of the [Fe(III)-Ru(II)] complex by red light (600-720 nm, 30 J cm-2), and resulted in enhanced cytotoxicity with photo-index ~45. The complex, [Fe(III)-Ru(II)] potentially bonded to the DNA binding by ruthenium moiety was responsible for minimal dark toxicity. The cytotoxic potential of the complex under red light was a result of the photo-induced accumulation of reactive oxygen species through both type I and type II photodynamic therapy (PDT) mechanisms in A549 and HeLa cells, while non-cancerous HPL1D cells remained unaffected. We probed the caspase 3/7-dependent apoptosis of the complex, [Fe(III)-Ru(II)], in vitro. Overall, the hetero-bimetallic [Fe(III)-Ru(II)] complex offered an ideal example of a red light activable dual-modality next-generation PDT tool for phototherapeutic anticancer therapy.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"85 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143192621","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}
The synthesis, complexation and main catalytic applications in enantioselective homogeneous catalysis of enantiopure single-atom-bridged diphosphorus ligands ((R1R2)P–X–P(R3R4); X = CR2, NR, O) is reviewed, covering literature up to the beginning of 2025. The information is organised by ligand type, with unsubstituted methylene-bridged (–CH2–) and substituted amino-bridged (–NR–) diphosphorus ligands being by far the most common type of ligands. The perspective review is completed by the analysis of all reported crystal structures of metallic complexes with the ligands. The bite angles, metal-phosphorus distances and buried volumes (Vbur) are given.
{"title":"Chiral Single-Atom-Bridged Diphosphorus Ligands: Synthesis, Complexation and Catalysis","authors":"Javier Eusamio, Arnald Grabulosa","doi":"10.1039/d4dt03572k","DOIUrl":"https://doi.org/10.1039/d4dt03572k","url":null,"abstract":"The synthesis, complexation and main catalytic applications in enantioselective homogeneous catalysis of enantiopure single-atom-bridged diphosphorus ligands ((R<small><sup>1</sup></small>R<small><sup>2</sup></small>)P–X–P(R<small><sup>3</sup></small>R<small><sup>4</sup></small>); X = CR<small><sub>2</sub></small>, NR, O) is reviewed, covering literature up to the beginning of 2025. The information is organised by ligand type, with unsubstituted methylene-bridged (–CH<small><sub>2</sub></small>–) and substituted amino-bridged (–NR–) diphosphorus ligands being by far the most common type of ligands. The perspective review is completed by the analysis of all reported crystal structures of metallic complexes with the ligands. The bite angles, metal-phosphorus distances and buried volumes (<em>V</em><small><sub>bur</sub></small>) are given.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"14 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143258415","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}
Hydride-ion (H−) conductors have garnered much attention owing to their high ionic conductivity and potential applications such as batteries and fuel/electrolysis cells. Perovskite-type H− conductors are known to exhibit relatively high ionic conductivity at room temperature. The present work demonstrated systematic material exploration within the SrLiH3–CaLiH3–NaLiH2 pseudo-ternary system. The Na-substituted system, Sr1−xNaxLiH3−x, exhibited a remarkable H− conductivity of 5.1 × 10–6 S cm−1 at 25 °C for Sr0.8Na0.2LiH2.8, marking the highest value reported among perovskite-type hydrides to date. Furthermore, we found a clear trend of enhanced H− conductivity with Ca substitution in the Sr1−xCaxLiH3 pseudo-binary system. However, in the Sr1−xCaxNayLiH3−y pseudo-ternary system, a negative synergistic effect of Ca and Na co-doping was observed. First-principles calculations revealed that this negative effect arises from a trade-off between migration and association energies in defect pairs of Na+ dopants and H− vacancies. These findings provide valuable insights into designing superior anion conductors.
{"title":"A trade-off between migration and association energies for hydride-ion conductivity in the SrLiH3–CaLiH3–NaLiH2 system","authors":"Takashi Hirose, Naoki Matsui, Kenta Watanabe, Takashi Saito, Kazuhiro Mori, Kota Suzuki, Masaaki Hirayama, Ryoji Kanno","doi":"10.1039/d4dt03384a","DOIUrl":"https://doi.org/10.1039/d4dt03384a","url":null,"abstract":"Hydride-ion (H<small><sup>−</sup></small>) conductors have garnered much attention owing to their high ionic conductivity and potential applications such as batteries and fuel/electrolysis cells. Perovskite-type H<small><sup>−</sup></small> conductors are known to exhibit relatively high ionic conductivity at room temperature. The present work demonstrated systematic material exploration within the SrLiH<small><sub>3</sub></small>–CaLiH<small><sub>3</sub></small>–NaLiH<small><sub>2</sub></small> pseudo-ternary system. The Na-substituted system, Sr<small><sub>1−<em>x</em></sub></small>Na<small><sub><em>x</em></sub></small>LiH<small><sub>3−<em>x</em></sub></small>, exhibited a remarkable H<small><sup>−</sup></small> conductivity of 5.1 × 10<small><sup>–6</sup></small> S cm<small><sup>−1</sup></small> at 25 °C for Sr<small><sub>0.8</sub></small>Na<small><sub>0.2</sub></small>LiH<small><sub>2.8</sub></small>, marking the highest value reported among perovskite-type hydrides to date. Furthermore, we found a clear trend of enhanced H<small><sup>−</sup></small> conductivity with Ca substitution in the Sr<small><sub>1−<em>x</em></sub></small>Ca<small><sub><em>x</em></sub></small>LiH<small><sub>3</sub></small> pseudo-binary system. However, in the Sr<small><sub>1−<em>x</em></sub></small>Ca<small><sub><em>x</em></sub></small>Na<small><sub><em>y</em></sub></small>LiH<small><sub>3−<em>y</em></sub></small> pseudo-ternary system, a negative synergistic effect of Ca and Na co-doping was observed. First-principles calculations revealed that this negative effect arises from a trade-off between migration and association energies in defect pairs of Na<small><sup>+</sup></small> dopants and H<small><sup>−</sup></small> vacancies. These findings provide valuable insights into designing superior anion conductors.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"40 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143124942","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}
In the pursuit of developping efficient and green methods for hydrogen production, a key focus is the development of the most energy-efficient catalysts. The analysis of various proton sources primarily aims at eliminating rate-limiting steps associated with protonation events and ensuring the stability of the catalyst. In this work, we report how two distinct proton sources can cause a mechanistic shift in the hydrogen evolution reaction. Specifically, we explore this reactivity change in the presence of triethylammonium and trifluoroacetic acid with two thiosemicarbazone-based complexes, using cobalt and nickel metal centers. Our results reveal that the catalytic mechansim can vary, depending on the proton source which demonstrates the importance of thoroughly investigating the interactions between a catalyst and a proton source to optimize hydrogen evolution systems.
{"title":"Hydrogen Evolution Reaction Mechanisms in Thiosemicarbazone Metal Complexes: A Combined Theoretical and Experimental Investigation on the Impact of Proton Source","authors":"Jana Mehrez, Alexandre Hernandes Barrozo, Léa Delmotte, Renaud Hardré, Michail Papadakis, Maylis Orio","doi":"10.1039/d4dt03507k","DOIUrl":"https://doi.org/10.1039/d4dt03507k","url":null,"abstract":"In the pursuit of developping efficient and green methods for hydrogen production, a key focus is the development of the most energy-efficient catalysts. The analysis of various proton sources primarily aims at eliminating rate-limiting steps associated with protonation events and ensuring the stability of the catalyst. In this work, we report how two distinct proton sources can cause a mechanistic shift in the hydrogen evolution reaction. Specifically, we explore this reactivity change in the presence of triethylammonium and trifluoroacetic acid with two thiosemicarbazone-based complexes, using cobalt and nickel metal centers. Our results reveal that the catalytic mechansim can vary, depending on the proton source which demonstrates the importance of thoroughly investigating the interactions between a catalyst and a proton source to optimize hydrogen evolution systems.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"40 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143124557","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}
In this study, two new photoluminescent film probes (LYH:Tb and LYH:Eu) were developed through chemical bath deposition. Benefiting from the antenna effect of DPA, these films can enhance the characteristic fluorescence emission of Tb3+ and Eu3+ through energy transfer, enabling stable fluorescence detection of the anthrax spore biomarker, pyridine dicarboxylic acid (DPA). By adding various aromatic organic compounds for selectivity studies, it was found that their fluorescence responses were much lower than that of DPA, indicating that the LYH:Tb and LYH:Eu film probes exhibited excellent sensitivity and anti-interference properties for DPA detection. The detection limits of the LYH:Tb and LYH:Eu film probes are as low as 86 nM and 14 nM, respectively. Moreover, the film probe is characterized by its simple synthesis, convenient storage, excellent stability, rapid response, and suitability for visual monitoring.
{"title":"One-step synthesis of LYH:Tb and LYH:Eu film probes and their application in Bacillus anthracis recognition","authors":"Yongping Guo, Haoxuan Zeng, Taihui Chen, Xiaoli Wu","doi":"10.1039/d4dt03442b","DOIUrl":"https://doi.org/10.1039/d4dt03442b","url":null,"abstract":"In this study, two new photoluminescent film probes (LYH:Tb and LYH:Eu) were developed through chemical bath deposition. Benefiting from the antenna effect of DPA, these films can enhance the characteristic fluorescence emission of Tb<small><sup>3+</sup></small> and Eu<small><sup>3+</sup></small> through energy transfer, enabling stable fluorescence detection of the anthrax spore biomarker, pyridine dicarboxylic acid (DPA). By adding various aromatic organic compounds for selectivity studies, it was found that their fluorescence responses were much lower than that of DPA, indicating that the LYH:Tb and LYH:Eu film probes exhibited excellent sensitivity and anti-interference properties for DPA detection. The detection limits of the LYH:Tb and LYH:Eu film probes are as low as 86 nM and 14 nM, respectively. Moreover, the film probe is characterized by its simple synthesis, convenient storage, excellent stability, rapid response, and suitability for visual monitoring.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"61 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083802","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}
Anton Rogozhin, Vasily A Ilichev, Dmitry Igorevich Pavlov, Mikhail N Bochkarev
Novel ditopic centrosymmetric soft-base ligands - 3,7-dihydrobenzo[1,2-d:4,5-d']bis(oxazole)-2,6-dithione (H2L1) and 3,7-dihydrobenzo[1,2-d:4,5-d']bis(thiazole)-2,6-dione (H2L2) have been obtained in one-pot way. Both compounds form 2D coordination polymers (CPs) by the reaction of free ligands with sodium bis(trismethylsilyl)amide in various solvent media. The H2L1 containing products are [Na2L1(DME)2]n (1) and [Na2L1(DMSO)4]n (2) and for H2L2 [Na6L23(DMSO)12]n (3) was formed. X-ray analysis revealed that compound 1 is a 2D CP in which deprotonated H2L1 acts as tetratopic linker, linking four sodium atoms via nitrogen and bridging sulfur. Unlike 1, in CP 2 deprotonated H2L1 acts as ditopic linker chelately coordinating sodium atoms in an unprecedented Na4O4 metallocenter formed by oxygens of DMSO molecules. Compound 3 is a 2D CP featuring rare Na3O6 secondary building unit (SBU) whereas the H2L2 exhibits both bridging and mixed chelating/bridging mode, linking four sodium atoms via nitrogen and oxygen atoms. Despite of the fact that free ligands H2L1 and H2L2 are non-luminescent in solutions and solid state, their deprotonated forms at 298 K in DME media demonstrate moderate photoluminescence (PL) in DME solutions with broad bands in the range 360-500 nm. At 77 K the same solutions show broadened and intense PL consisting of bands in the region 360-670 nm corresponding to the ligand fluorescence and phosphorescence. CPs 1-3 in solid state exhibit PL both at 298 and 77 K. At 298 K CPs 1 and 3 exhibit intense fluorescence in the range 370-450 nm and moderate microsecond timescale phosphorescence in the range 500-670 nm, while CP 2 exhibit only fluorescence. Upon cooling to 77 K all CPs 1-3 demonstrate both fluorescence and phosphorescence. Based on the low temperature phosphorescence spectra of 1 and 3 in DME solutions the triplet energy levels of H2L1 and H2L2 were established at 21000 and 20800 cm-1 respectively.
{"title":"Structurally Isomeric Ditopic 2-Mercaptobenzoxazole and 2-Hydroxybenzothiazole as Ligands for Design of 2D Sodium-Based Luminescent Coordination Polymers","authors":"Anton Rogozhin, Vasily A Ilichev, Dmitry Igorevich Pavlov, Mikhail N Bochkarev","doi":"10.1039/d4dt03427a","DOIUrl":"https://doi.org/10.1039/d4dt03427a","url":null,"abstract":"Novel ditopic centrosymmetric soft-base ligands - 3,7-dihydrobenzo[1,2-d:4,5-d']bis(oxazole)-2,6-dithione (H2L1) and 3,7-dihydrobenzo[1,2-d:4,5-d']bis(thiazole)-2,6-dione (H2L2) have been obtained in one-pot way. Both compounds form 2D coordination polymers (CPs) by the reaction of free ligands with sodium bis(trismethylsilyl)amide in various solvent media. The H2L1 containing products are [Na2L1(DME)2]n (1) and [Na2L1(DMSO)4]n (2) and for H2L2 [Na6L23(DMSO)12]n (3) was formed. X-ray analysis revealed that compound 1 is a 2D CP in which deprotonated H2L1 acts as tetratopic linker, linking four sodium atoms via nitrogen and bridging sulfur. Unlike 1, in CP 2 deprotonated H2L1 acts as ditopic linker chelately coordinating sodium atoms in an unprecedented Na4O4 metallocenter formed by oxygens of DMSO molecules. Compound 3 is a 2D CP featuring rare Na3O6 secondary building unit (SBU) whereas the H2L2 exhibits both bridging and mixed chelating/bridging mode, linking four sodium atoms via nitrogen and oxygen atoms. Despite of the fact that free ligands H2L1 and H2L2 are non-luminescent in solutions and solid state, their deprotonated forms at 298 K in DME media demonstrate moderate photoluminescence (PL) in DME solutions with broad bands in the range 360-500 nm. At 77 K the same solutions show broadened and intense PL consisting of bands in the region 360-670 nm corresponding to the ligand fluorescence and phosphorescence. CPs 1-3 in solid state exhibit PL both at 298 and 77 K. At 298 K CPs 1 and 3 exhibit intense fluorescence in the range 370-450 nm and moderate microsecond timescale phosphorescence in the range 500-670 nm, while CP 2 exhibit only fluorescence. Upon cooling to 77 K all CPs 1-3 demonstrate both fluorescence and phosphorescence. Based on the low temperature phosphorescence spectra of 1 and 3 in DME solutions the triplet energy levels of H2L1 and H2L2 were established at 21000 and 20800 cm-1 respectively.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"10 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083811","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}
Yuri Orlov, Vyacheslav A Dudnikov, Sergei Vereshchagin, Yuri Ustyuzhanin, Sergey Nikolaev, Sergey M. Zharkov, Michail N. Volochaev, Galina Zeer, Sergey Gavrilkin, Alexey Tsvetkov, Sergei G Ovchinnikov
It is known that in a weak magnetic field ($H < 1$~kOe) at $T < T_C approx 87$~K, rare-earth cobalt oxide LaCoO$_3$ has ferromagnetic properties. The physical mechanism of the ferromagnetism emergence in LaCoO$_3$ is still remains unclear. We provided experimental evidence of the ferromagnetism and crystal lattice interconnection -- the cause of ferromagnetic ordering is the near surface (defects) structural stresses. A theoretical model is proposed, within the framework of which the mechanism of the emergence of the magnetically ordered state in LaCoO$_3$ is discussed.
{"title":"Ferromagnetism in LaCoO$_3$. Relationship between crystal structure, morphology and magnetic properties","authors":"Yuri Orlov, Vyacheslav A Dudnikov, Sergei Vereshchagin, Yuri Ustyuzhanin, Sergey Nikolaev, Sergey M. Zharkov, Michail N. Volochaev, Galina Zeer, Sergey Gavrilkin, Alexey Tsvetkov, Sergei G Ovchinnikov","doi":"10.1039/d4dt03135k","DOIUrl":"https://doi.org/10.1039/d4dt03135k","url":null,"abstract":"It is known that in a weak magnetic field ($H < 1$~kOe) at $T < T_C approx 87$~K, rare-earth cobalt oxide LaCoO$_3$ has ferromagnetic properties. The physical mechanism of the ferromagnetism emergence in LaCoO$_3$ is still remains unclear. We provided experimental evidence of the ferromagnetism and crystal lattice interconnection -- the cause of ferromagnetic ordering is the near surface (defects) structural stresses. A theoretical model is proposed, within the framework of which the mechanism of the emergence of the magnetically ordered state in LaCoO$_3$ is discussed.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"24 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083814","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}
The synthesis and full characterization of 1,4-dilithio-1,4-bis(triisopropylsilyl)-2,3-diphenylbuta-1,3-diene (1b) are reported. This molecule featuring extremely bulky silyl groups at the 1- and 4-positions serves as a precursor for the synthesis of 2,5-bis(triisopropylsilyl)-3,4-diphenyl-1-silacyclopenta-1,3-dienes (siloles) bearing various substituents at the silicon atom (SiR2 = SiH2 (4), SiH(OMe) (5), SiF2 (6), SiBr2 (7), SiBr(OMe) (8)). Importantly, compounds 6 and 7 reacted with lithium to afford 2,5-bis(triisopropylsilyl)-3,4-diphenyldilithiosilole (9). The solid-state molecular structure and solution NMR spectra reveal the formation of an aromatic ring system, as opposed to the precursors 6 and 7, with two Li cations coordinated by the silacycle in an η5-fashion. The sterically bulky dilithiosilole 9 can be applied as an important starting material in the pursuit of low-valent silicon species without donor stabilization.
{"title":"Synthesis of a dilithiobutadiene bearing extremely bulky silyl substituents and its reactivity toward functionalized silanes","authors":"Masaichi Saito, Katharina Muenster, Shunsuke Kudo, Takuya Kuwabara, Eriko Shimamura, Shunsuke Furukawa, Yusuke Yoshida, Shintaro Ishida, Takeaki Iwamoto, Kazuki Tanifuji, Yasuhiro Ohki, Mao Minoura","doi":"10.1039/d4dt03537b","DOIUrl":"https://doi.org/10.1039/d4dt03537b","url":null,"abstract":"The synthesis and full characterization of 1,4-dilithio-1,4-bis(triisopropylsilyl)-2,3-diphenylbuta-1,3-diene (1b) are reported. This molecule featuring extremely bulky silyl groups at the 1- and 4-positions serves as a precursor for the synthesis of 2,5-bis(triisopropylsilyl)-3,4-diphenyl-1-silacyclopenta-1,3-dienes (siloles) bearing various substituents at the silicon atom (SiR2 = SiH2 (4), SiH(OMe) (5), SiF2 (6), SiBr2 (7), SiBr(OMe) (8)). Importantly, compounds 6 and 7 reacted with lithium to afford 2,5-bis(triisopropylsilyl)-3,4-diphenyldilithiosilole (9). The solid-state molecular structure and solution NMR spectra reveal the formation of an aromatic ring system, as opposed to the precursors 6 and 7, with two Li cations coordinated by the silacycle in an η5-fashion. The sterically bulky dilithiosilole 9 can be applied as an important starting material in the pursuit of low-valent silicon species without donor stabilization.","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":"143083634","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}
Two isostructural thiacalix[4]arene-capped Ln8 aggregates with a “hand in hand” structure, designated as {Ln8(μ4-OH)2Cl2(TC4A)4(BCT)2(DMF)(6-x)(CH3OH)(2+x)(H2O)2}•mCH3OH•nDMF (Ln = Tb (1), Eu (2); H4TC4A = p-tert-butylthiacalix[4]arene; H2BCT = 3,5-bis(4’-carboxy-phenyl)-1,2,4-triazole; DMF = N,N’-dimethylformamide), were constructed from two sandwich-like Ln4-(TC4A)2 entities bridged via two BCT2- linkers. These aggregates present a layer-like structure on the ac plane, with poly-nuclear secondary building units (PSBUs) staggered and assembled in three-dimensional space. 1 exhibits green photoluminescence under 379 nm excitation, with an average decay time of approximately 1.15 ms. Notably, the metal-centered luminescence of 1 remains nearly stable even after replacing the DMF molecules with methanol. The structural stability of 1 in various solvents, along with its excellent photoluminescent properties after immersed in water for several months, suggests that it could effectively resist luminescence quenching. This makes it a promising candidate for applications in anti-counterfeiting and luminescence detection. In contrast, 2 does not show visible luminescence under the irradiation of a portable ultraviolet lamp (λ = 326 nm), which could be attributed to the slight difference in ligand-based energy levels. Collectively, these findings enhanced the understanding of the structural diversity and application scenarios of thiacalix[4]arene-capped Ln(III) aggregates.
{"title":"Thiacalix[4]arene-Capped Ln(III) Aggregates with “Hand in Hand” Structures and their Luminescent Properties","authors":"Hongbo Gao, Hao Wang, Chenxing Liu, Qicao Yan, Yanyan Wang, He-Rui Wen, Hongpeng You, Zhaomin Hao, Wuping Liao","doi":"10.1039/d4dt03308f","DOIUrl":"https://doi.org/10.1039/d4dt03308f","url":null,"abstract":"Two isostructural thiacalix[4]arene-capped Ln8 aggregates with a “hand in hand” structure, designated as {Ln8(μ4-OH)2Cl2(TC4A)4(BCT)2(DMF)(6-x)(CH3OH)(2+x)(H2O)2}•mCH3OH•nDMF (Ln = Tb (1), Eu (2); H4TC4A = p-tert-butylthiacalix[4]arene; H2BCT = 3,5-bis(4’-carboxy-phenyl)-1,2,4-triazole; DMF = N,N’-dimethylformamide), were constructed from two sandwich-like Ln4-(TC4A)2 entities bridged via two BCT2- linkers. These aggregates present a layer-like structure on the ac plane, with poly-nuclear secondary building units (PSBUs) staggered and assembled in three-dimensional space. 1 exhibits green photoluminescence under 379 nm excitation, with an average decay time of approximately 1.15 ms. Notably, the metal-centered luminescence of 1 remains nearly stable even after replacing the DMF molecules with methanol. The structural stability of 1 in various solvents, along with its excellent photoluminescent properties after immersed in water for several months, suggests that it could effectively resist luminescence quenching. This makes it a promising candidate for applications in anti-counterfeiting and luminescence detection. In contrast, 2 does not show visible luminescence under the irradiation of a portable ultraviolet lamp (λ = 326 nm), which could be attributed to the slight difference in ligand-based energy levels. Collectively, these findings enhanced the understanding of the structural diversity and application scenarios of thiacalix[4]arene-capped Ln(III) aggregates.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"82 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143083800","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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