A diiron(III)-gaticarboxylic acid (H-Gat) complex, [Fe2(Gat)4(μ-OCH3)2] (FeGa1), (H-Gat= 1-cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-3-quinolinecarboxylic acid), was designed and evaluated for antiproliferative activity in comparison with 5,7-dichloro-2-methyl-8-quinolinol (H-Dmq) diiron(III) complex, [Fe2(Dmq)4(μ-O)] (FeGa2). Compared to the H-Gat and H-Dmq ligands, complex FeGa1 showed a higher cytotoxicity towards human cervical SiHa cancer cells, with IC50 value was 0.11 ± 0.01 μM (cisplatin (CPL): 10.29 ± 0.46 μM and FeGa2: 2.15 ± 0.72 μM respectively). Mechanistic studies indicated that FeGa1 and FeGa2 can trigger SiHa cell apoptosis and senescence via activating caspase-3/7, inducing DNA damage and inhibiting of hTERT, which was in the following order: FeGa1 > FeGa2. According to the iron (Fe) uptake assay, FeGa1 showed significantly higher cellular Fe accumulation in nuclear fraction than FeGa2; this difference can be unambiguously attributed to the chelating properties conferred by the H-Gat ligand in FeGa1. This may well explain the higher cytotoxicity and the more significant anticancer mechanism of FeGa1 throughout the study. Importantly, the compound FeGa1, with H-Gat ligand, which was selected for in vivo test, showed tumor growth inhibition rates (TGIR, ca. 52.9%). Overall, the diiron(III)-H-Gat complex FeGa1 demonstrates promising potential as a potent antiproliferative agent.
{"title":"Preparation of two new diiron(III)-gaticarboxylic acid complexes and exploration of their in vitro and in vivo cytotoxic activities","authors":"Tai-Ming Shao,Xiao-Zhen Qin,Li-Lin Jiang,Fu-Liu Luo,Qiu‑Ji Xie,Hai-Xia Liao,Mingxiong Tan,Hong Liang,Qi-Pin Qin","doi":"10.1039/d6dt01390b","DOIUrl":"https://doi.org/10.1039/d6dt01390b","url":null,"abstract":"A diiron(III)-gaticarboxylic acid (H-Gat) complex, [Fe2(Gat)4(μ-OCH3)2] (FeGa1), (H-Gat= 1-cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-3-quinolinecarboxylic acid), was designed and evaluated for antiproliferative activity in comparison with 5,7-dichloro-2-methyl-8-quinolinol (H-Dmq) diiron(III) complex, [Fe2(Dmq)4(μ-O)] (FeGa2). Compared to the H-Gat and H-Dmq ligands, complex FeGa1 showed a higher cytotoxicity towards human cervical SiHa cancer cells, with IC50 value was 0.11 ± 0.01 μM (cisplatin (CPL): 10.29 ± 0.46 μM and FeGa2: 2.15 ± 0.72 μM respectively). Mechanistic studies indicated that FeGa1 and FeGa2 can trigger SiHa cell apoptosis and senescence via activating caspase-3/7, inducing DNA damage and inhibiting of hTERT, which was in the following order: FeGa1 > FeGa2. According to the iron (Fe) uptake assay, FeGa1 showed significantly higher cellular Fe accumulation in nuclear fraction than FeGa2; this difference can be unambiguously attributed to the chelating properties conferred by the H-Gat ligand in FeGa1. This may well explain the higher cytotoxicity and the more significant anticancer mechanism of FeGa1 throughout the study. Importantly, the compound FeGa1, with H-Gat ligand, which was selected for in vivo test, showed tumor growth inhibition rates (TGIR, ca. 52.9%). Overall, the diiron(III)-H-Gat complex FeGa1 demonstrates promising potential as a potent antiproliferative agent.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"18 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248580","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}
Nikhil Sodhi, Rajni Kadian, Andrea Baschieri, Riccardo Amorati, Zongxin Jin, Kunal Madaan, Vijay P Singh
2-Methyl benzoselenazoles were synthesized via the reaction of in situ-generated sodium selenolate with acetyl chloride at room temperature. Single-crystal X-ray diffraction confirmed a nearly planar structure due to non-bonding Se⋯O interactions, supported by computational analyses. All compounds exhibited good glutathione peroxidase-like antioxidant activity in a coupled reductase assay, as compared to the reference, ebselen. The most active compound was further evaluated under varying concentrations of glutathione to gain deeper insights into its catalytic efficiency. 77Se{1H} NMR mechanistic study was performed to provide evidence for the key intermediates involved in the decomposition of peroxide. The radical-trapping antioxidant activity of benzoselenazoles was evaluated by the inhibition of azo-initiated autoxidation of cumene in chlorobenzene. It showed peroxyl radical-trapping capability, with an inhibition constant of 1.4 × 103 M-1 s-1 and a stoichiometric factor (n) ≈ 2, due to H-atom transfer from the amide group, as further confirmed by theoretical calculations. In addition to their antioxidant activities, molecular dynamics studies revealed favourable binding interactions with vascular endothelial growth factor receptor-2 (VEGFR-2), suggesting dual antioxidant and anti-angiogenic roles.
{"title":"Inhibition of the lipid peroxidation and glutathione peroxidase-like activity of 2-methyl benzoselenazoles.","authors":"Nikhil Sodhi, Rajni Kadian, Andrea Baschieri, Riccardo Amorati, Zongxin Jin, Kunal Madaan, Vijay P Singh","doi":"10.1039/d6dt01465h","DOIUrl":"https://doi.org/10.1039/d6dt01465h","url":null,"abstract":"<p><p>2-Methyl benzoselenazoles were synthesized <i>via</i> the reaction of <i>in situ</i>-generated sodium selenolate with acetyl chloride at room temperature. Single-crystal X-ray diffraction confirmed a nearly planar structure due to non-bonding Se⋯O interactions, supported by computational analyses. All compounds exhibited good glutathione peroxidase-like antioxidant activity in a coupled reductase assay, as compared to the reference, ebselen. The most active compound was further evaluated under varying concentrations of glutathione to gain deeper insights into its catalytic efficiency. <sup>77</sup>Se{<sup>1</sup>H} NMR mechanistic study was performed to provide evidence for the key intermediates involved in the decomposition of peroxide. The radical-trapping antioxidant activity of benzoselenazoles was evaluated by the inhibition of azo-initiated autoxidation of cumene in chlorobenzene. It showed peroxyl radical-trapping capability, with an inhibition constant of 1.4 × 10<sup>3</sup> M<sup>-1</sup> s<sup>-1</sup> and a stoichiometric factor (<i>n</i>) ≈ 2, due to H-atom transfer from the amide group, as further confirmed by theoretical calculations. In addition to their antioxidant activities, molecular dynamics studies revealed favourable binding interactions with vascular endothelial growth factor receptor-2 (VEGFR-2), suggesting dual antioxidant and anti-angiogenic roles.</p>","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149259639","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}
Qi Sun,Victoria E Wright,Darren S. Lee,Ignas Motuzis,Harry C Sample,Timothy J Prior,Mark Robert James Elsegood,Carl Redshaw
A number of interesting iron-containing calix[n]arene (n = 6, 8) species have been isolated from reactions involving either: in-situ generated heterobimetallic iron alkoxides of the type [MFe(Ot-Bu)3] (M = Na, K) and the parent calixarenes (L6H6 = p-tert-butylcalix[6]areneH6 or L8H8 = p-tert-butylcalix[8]areneH8) or, in the case of LdioxaH6 = p-tert-butyltetrahomodioxacalix[6]areneH6, reaction with [Fe(Ot-Bu)2]. Initial reactions involving the use of L6H6/n-BuLi followed by either FeBr2 or FeBr3 led to the isolation of only lithium-containing calix[6]arene complexes, namely [Li8(L6H2)2(H2O)(MeCN)7]∙6.5MeCN (1∙6.5MeCN), {[(L6H2)Li6(NCMe)2]2(O)2(H2O)2X2}∙14MeCN (2∙14MeCN; X = 94%OH, 6%Br). However, the use of L6H6/Na[Fe(Ot-Bu)3] led to the isolation of [Fe3.93Na4.07(L6)(L6H2)(O)(OH)(NCMe)7.75]∙5.75MeCN (3∙5.75MeCN), whilst for LdioxaH6, [Fe(NCMe)2(LdioxaH4)]∙3MeCN (4∙3MeCN) was isolated. In the case of L8H8, the combination with n-BuLi and subsequently FeCl2 led to [(FeCl)2Fe2(μ3-O)2{Li(NCMe)2}2{Li(NCMe)0.691(THF)0.309}2(L8)(Ot-Bu)2] (5), whereas the use of M{Fe(Ot-Bu)3] (M = Na, K) led to the isolation of {Na[(Fe2O(L8)(Na(NCMe))2)2Fe]}∙18MeCN (6∙18MeCN), [Fe6O4(L8)(L8H2)Na4(NCMe)5(OH2)(OH)][Fe6O4(L8)(L8H2)Na4(NCMe)4(OH2)2(OH)]∙Na(NCMe)4∙Na∙13MeCN (7∙Na(NCMe)4∙Na∙13MeCN), [Fe(L8H4)K3(NCMe)5]2∙8MeCN (8∙8MeCN) and [(Fe2K2)(O)(NCMe)5(L8H2)]·5.5MeCN (9·5.5MeCN). The molecular structures of 1 - 9 have been determined. These complexes have been screened as catalysts for the ring opening polymerization (ROP) of the cyclic esters epsilon-caprolactone (epsilon-CL) and delta-valerolactone (delta-VL) with and without benzyl alcohol (BnOH) present. For comparison, the precursors M[Fe(Ot-Bu)3] (M = Na, K) were screened under the same conditions. Results revealed that for the ROP of epsilon-CL, the catalysts generally performed better under air, with kinetic data revealing the trend 9 > 7 > 6 ≈ 3 > 8 > 5 ≈ 4 ≈ 5 ≈ 1 ≈ 2. For delta-VL, conversions across all catalytic systems were much higher, with the rate trend 6 > 9 > 7 > 4 > 3 > 8 > 1 ≈ 5 ≈ 2. MALDI-ToF spectra revealed that different families of products were formed including linear polymers (with end groups H/OH or H/OBn) and cyclic polymers.
{"title":"Heterometallic iron calix[n]arenes (n = 6, 8): Structure and ring opening polymerization capability","authors":"Qi Sun,Victoria E Wright,Darren S. Lee,Ignas Motuzis,Harry C Sample,Timothy J Prior,Mark Robert James Elsegood,Carl Redshaw","doi":"10.1039/d6dt01989g","DOIUrl":"https://doi.org/10.1039/d6dt01989g","url":null,"abstract":"A number of interesting iron-containing calix[n]arene (n = 6, 8) species have been isolated from reactions involving either: in-situ generated heterobimetallic iron alkoxides of the type [MFe(Ot-Bu)3] (M = Na, K) and the parent calixarenes (L6H6 = p-tert-butylcalix[6]areneH6 or L8H8 = p-tert-butylcalix[8]areneH8) or, in the case of LdioxaH6 = p-tert-butyltetrahomodioxacalix[6]areneH6, reaction with [Fe(Ot-Bu)2]. Initial reactions involving the use of L6H6/n-BuLi followed by either FeBr2 or FeBr3 led to the isolation of only lithium-containing calix[6]arene complexes, namely [Li8(L6H2)2(H2O)(MeCN)7]∙6.5MeCN (1∙6.5MeCN), {[(L6H2)Li6(NCMe)2]2(O)2(H2O)2X2}∙14MeCN (2∙14MeCN; X = 94%OH, 6%Br). However, the use of L6H6/Na[Fe(Ot-Bu)3] led to the isolation of [Fe3.93Na4.07(L6)(L6H2)(O)(OH)(NCMe)7.75]∙5.75MeCN (3∙5.75MeCN), whilst for LdioxaH6, [Fe(NCMe)2(LdioxaH4)]∙3MeCN (4∙3MeCN) was isolated. In the case of L8H8, the combination with n-BuLi and subsequently FeCl2 led to [(FeCl)2Fe2(μ3-O)2{Li(NCMe)2}2{Li(NCMe)0.691(THF)0.309}2(L8)(Ot-Bu)2] (5), whereas the use of M{Fe(Ot-Bu)3] (M = Na, K) led to the isolation of {Na[(Fe2O(L8)(Na(NCMe))2)2Fe]}∙18MeCN (6∙18MeCN), [Fe6O4(L8)(L8H2)Na4(NCMe)5(OH2)(OH)][Fe6O4(L8)(L8H2)Na4(NCMe)4(OH2)2(OH)]∙Na(NCMe)4∙Na∙13MeCN (7∙Na(NCMe)4∙Na∙13MeCN), [Fe(L8H4)K3(NCMe)5]2∙8MeCN (8∙8MeCN) and [(Fe2K2)(O)(NCMe)5(L8H2)]·5.5MeCN (9·5.5MeCN). The molecular structures of 1 - 9 have been determined. These complexes have been screened as catalysts for the ring opening polymerization (ROP) of the cyclic esters epsilon-caprolactone (epsilon-CL) and delta-valerolactone (delta-VL) with and without benzyl alcohol (BnOH) present. For comparison, the precursors M[Fe(Ot-Bu)3] (M = Na, K) were screened under the same conditions. Results revealed that for the ROP of epsilon-CL, the catalysts generally performed better under air, with kinetic data revealing the trend 9 > 7 > 6 ≈ 3 > 8 > 5 ≈ 4 ≈ 5 ≈ 1 ≈ 2. For delta-VL, conversions across all catalytic systems were much higher, with the rate trend 6 > 9 > 7 > 4 > 3 > 8 > 1 ≈ 5 ≈ 2. MALDI-ToF spectra revealed that different families of products were formed including linear polymers (with end groups H/OH or H/OBn) and cyclic polymers.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"4 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248576","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}
Robin Turnbull,Pablo Salcedo-Abraira,Estelina Lora da Silva,Jordi Ibañez-Insa,Akun Liang,M Jasmin,Francisco Javier Manjón,Antonio Rodríguez Diéguez,Daniel Errandonea
K₂Ni(IO₃)₄(H₂O)₂, a new nickel-containing iodate with a previously unreported composition, has been synthesised using a single-diffusion gel technique and structurally characterised by single-crystal X-ray diffraction. The compound adopts a known structure type within this family, containing trigonal pyramidal IO₃⁻ units with stereochemically active lone electron pairs, together with secondary I•••O interactions and hydrogen bonding involving water molecules. The structural model and estimated band gap are supported by density functional theory calculations. Thermogravimetric analysis confirms the presence and amount of water, Raman spectroscopy identifies the characteristic vibrational modes of the iodate and hydroxyl groups, and optical absorption measurements provide an estimate of the band gap.
{"title":"Synthesis and Crystal Structure of KNi(IO)(HO)","authors":"Robin Turnbull,Pablo Salcedo-Abraira,Estelina Lora da Silva,Jordi Ibañez-Insa,Akun Liang,M Jasmin,Francisco Javier Manjón,Antonio Rodríguez Diéguez,Daniel Errandonea","doi":"10.1039/d6dt01545j","DOIUrl":"https://doi.org/10.1039/d6dt01545j","url":null,"abstract":"K₂Ni(IO₃)₄(H₂O)₂, a new nickel-containing iodate with a previously unreported composition, has been synthesised using a single-diffusion gel technique and structurally characterised by single-crystal X-ray diffraction. The compound adopts a known structure type within this family, containing trigonal pyramidal IO₃⁻ units with stereochemically active lone electron pairs, together with secondary I•••O interactions and hydrogen bonding involving water molecules. The structural model and estimated band gap are supported by density functional theory calculations. Thermogravimetric analysis confirms the presence and amount of water, Raman spectroscopy identifies the characteristic vibrational modes of the iodate and hydroxyl groups, and optical absorption measurements provide an estimate of the band gap.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"2 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248579","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}
M. Gautier,J. Lin,E. Guerinoni,L. Daronnat,S. Pellet-Rostaing,S. Dourdain
Selective uranium extraction from sulfate and phosphate-based leachates remains challenging due to co-extraction of impurities such as Mo, Zr, and Fe, which limits process efficiency and economic viability. This study investigates how the nature and concentration of phase modifiers influence uranium selectivity across three mining systems: two conventional uranium ores and one phosphate-associated ore. U, Mo and Zr were quantified by ICP-OES, while Fe was analyzed by gamma-ray spectrometry. Results show that phase modifier effects on selectivity are highly system dependent. In AMEX-based sulfate systems, increasing EXXAL 10 enhances selectivity through systematic improvements in extraction performance: in Mine A, U/Zr increases from 50 to 221 at 50 vol% (vs. 5 vol% industrial conditions), while in Mine B, U/Mo increases from 377 to 1459 at 22 vol%, with optimal U/Zr selectivity between 10–50 vol%. In contrast, the phosphate-based Mine C exhibits a weakly structured organic phase, with dimer-dominated extractant species and limited sensitivity to phase modifier addition; optimal selectivity is achieved at low modifier content, where 2 vol% EXXAL 13 increases the U/Fe ratio from 61 to 214. These results highlight the importance of system-specific phase modifier optimization for maximizing uranium selectivity. SAXS analysis further reveals that extractant molecules self-assemble into reverse aggregates whose structure and inter-aggregate interactions are strongly influenced by phase modifier concentration. Crucially, these structural modifications directly correlate with selectivity variations, demonstrating that phase modifier effects are fundamentally mediated through changes in extractant aggregation in the organic phase.
{"title":"Tailoring phase modifiers for selective uranium extraction: conventional and phosphate ores","authors":"M. Gautier,J. Lin,E. Guerinoni,L. Daronnat,S. Pellet-Rostaing,S. Dourdain","doi":"10.1039/d6dt01684g","DOIUrl":"https://doi.org/10.1039/d6dt01684g","url":null,"abstract":"Selective uranium extraction from sulfate and phosphate-based leachates remains challenging due to co-extraction of impurities such as Mo, Zr, and Fe, which limits process efficiency and economic viability. This study investigates how the nature and concentration of phase modifiers influence uranium selectivity across three mining systems: two conventional uranium ores and one phosphate-associated ore. U, Mo and Zr were quantified by ICP-OES, while Fe was analyzed by gamma-ray spectrometry. Results show that phase modifier effects on selectivity are highly system dependent. In AMEX-based sulfate systems, increasing EXXAL 10 enhances selectivity through systematic improvements in extraction performance: in Mine A, U/Zr increases from 50 to 221 at 50 vol% (vs. 5 vol% industrial conditions), while in Mine B, U/Mo increases from 377 to 1459 at 22 vol%, with optimal U/Zr selectivity between 10–50 vol%. In contrast, the phosphate-based Mine C exhibits a weakly structured organic phase, with dimer-dominated extractant species and limited sensitivity to phase modifier addition; optimal selectivity is achieved at low modifier content, where 2 vol% EXXAL 13 increases the U/Fe ratio from 61 to 214. These results highlight the importance of system-specific phase modifier optimization for maximizing uranium selectivity. SAXS analysis further reveals that extractant molecules self-assemble into reverse aggregates whose structure and inter-aggregate interactions are strongly influenced by phase modifier concentration. Crucially, these structural modifications directly correlate with selectivity variations, demonstrating that phase modifier effects are fundamentally mediated through changes in extractant aggregation in the organic phase.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"79 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248582","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}
Igor P. Gloriozov,Zoia Sizova,Nelly Zhokhova,Yuri Ustynyuk,Cheng-Peng Li,Valentine Nenajdenko
IIn this study, density functional theory was used to perform quantum chemical modeling of the structure and properties of ion pairs formed by cations of N-methylated five- and six-membered heterocycles with the pertechnetate anion TcO₄⁻. It was found that the mutual spatial orientation of the cation and anion in these ion pairs is determined by two types of non-covalent interactions: the formation of O3Tc-O-…H-C hydrogen bonds and the n→π* interaction, as a result of which the electron density from the anion oxygen atoms is partially transferred to the lowest unoccupied π-orbitals (LUMO) of electron-deficient aromatic N-heterocycles. The anion/cation binding energies ΔG in ion pairs increase with decreasing LUMO energy of the heterocycles, and a linear correlation of ΔG with the LUMO of the cationic receptors is observed. In the series of five-membered heterocycles (imidazoles, triazoles, tetrazoles), the contributions of hydrogen bonding and n→π* interactions to the binding energy of TcO4- with N-alkylimidazolium and N-alkyltriazolium cations are comparable in magnitude, but for N-alkyltetrazolium-based receptors, the latter contribution is dominant. n→π* interaction also makes a more significant contribution to the binding of anions by receptors based on six-membered heterocycles (pyridines, pyrimidines, pyrazines, 1,3,5-triazines), which have lower LUMO energies. The LUMO energies of cationic receptors decrease with an increase in the number of nitrogen atoms in the heterocycle and with the introduction of electron-withdrawing substituents, which leads to an increase in the binding energy ΔG. The new data obtained and the identified patterns open up opportunities for fine-tuning the binding energy of anions to the receptor through relatively simple and straightforward structural modifications. These patterns must be taken into account when developing cationic receptors for oxoanions. In particular, the synthesis and characterization of cationic receptors for the pertechnetate anion TcO4- containing triazole, tetrazole, and 1,3,5-triazine cores, which have not yet been described, appear highly promising.
{"title":"Cationic receptors based on five-membered and six-membered aromatic N-heterocycles for pertechnetate anion binding in aqueous solutions. Comparative DFT analysis","authors":"Igor P. Gloriozov,Zoia Sizova,Nelly Zhokhova,Yuri Ustynyuk,Cheng-Peng Li,Valentine Nenajdenko","doi":"10.1039/d6dt01557c","DOIUrl":"https://doi.org/10.1039/d6dt01557c","url":null,"abstract":"IIn this study, density functional theory was used to perform quantum chemical modeling of the structure and properties of ion pairs formed by cations of N-methylated five- and six-membered heterocycles with the pertechnetate anion TcO₄⁻. It was found that the mutual spatial orientation of the cation and anion in these ion pairs is determined by two types of non-covalent interactions: the formation of O3Tc-O-…H-C hydrogen bonds and the n→π* interaction, as a result of which the electron density from the anion oxygen atoms is partially transferred to the lowest unoccupied π-orbitals (LUMO) of electron-deficient aromatic N-heterocycles. The anion/cation binding energies ΔG in ion pairs increase with decreasing LUMO energy of the heterocycles, and a linear correlation of ΔG with the LUMO of the cationic receptors is observed. In the series of five-membered heterocycles (imidazoles, triazoles, tetrazoles), the contributions of hydrogen bonding and n→π* interactions to the binding energy of TcO4- with N-alkylimidazolium and N-alkyltriazolium cations are comparable in magnitude, but for N-alkyltetrazolium-based receptors, the latter contribution is dominant. n→π* interaction also makes a more significant contribution to the binding of anions by receptors based on six-membered heterocycles (pyridines, pyrimidines, pyrazines, 1,3,5-triazines), which have lower LUMO energies. The LUMO energies of cationic receptors decrease with an increase in the number of nitrogen atoms in the heterocycle and with the introduction of electron-withdrawing substituents, which leads to an increase in the binding energy ΔG. The new data obtained and the identified patterns open up opportunities for fine-tuning the binding energy of anions to the receptor through relatively simple and straightforward structural modifications. These patterns must be taken into account when developing cationic receptors for oxoanions. In particular, the synthesis and characterization of cationic receptors for the pertechnetate anion TcO4- containing triazole, tetrazole, and 1,3,5-triazine cores, which have not yet been described, appear highly promising.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"9 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248586","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}
Yongxia Zhang,Suncheng Wang,Yilin Sun,Handong Gu,Xinsheng Zhao,Xiao-Jun Wang,Ke Cheng,Qiu-Yan Li
CO2 is both an abundant, renewable C1 feedstock and a major greenhouse gas, making its efficient utilization a central challenge in sustainable chemistry. The carboxylative cyclization of propargylic amines with CO2 represents an inherently atom-economical route to oxazolidinones, an important class of heterocycles with broad applications in pharmaceuticals and fine chemicals. However, the development of robust catalysts that operate under mild conditions remains challenging. Herein, we report a mixed-valence Cu(I)/Cu(II) trinuclear cluster-based metal-organic framework (MOF), TPE2Pz-Cu, synthesized solvothermally from 1,1-bis(4-(1H-pyrazol-4-yl)phenyl)-2,2-diphenylethene (TPE2Pz) and Cu(NO3). The all-nitrogen coordination environment of the trinuclear copper clusters endows the framework with high thermal and chemical stability. Electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) analyses confirm the coexistence of Cu(I) and Cu(II) centers within the trinuclear cluster. With substoichiometric organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, 0.1 equiv.) as a co-catalyst, TPE2Pz-Cu mediates the carboxylative cyclization of propargylic amines at 60 oC under a CO2 balloon atmosphere, delivering oxazolidinones in yields of up to >99% with a turnover number (TON) of 220.8 and a turnover frequency (TOF) of 36.8 h⁻¹. The catalyst tolerates a broad substrate scope and retains >80% yield over five consecutive runs, reflecting its structural robustness. Mechanistic studies reveal that the Cu centers activate the alkynyl groups of propargylic amines whilst DBU facilitates deprotonation of the amino group, and the framework's high CO₂ affinity and ordered porous channels further facilitate CO₂ enrichment and pre-organization within the confined pore environment, thereby promoting the cyclization.
{"title":"Mixed-Valence Cu(I)/Cu(II) Trinuclear Cluster-Based Metal-Organic Framework for Efficient CO 2 Fixation into Oxazolidinones via Propargylic Amines","authors":"Yongxia Zhang,Suncheng Wang,Yilin Sun,Handong Gu,Xinsheng Zhao,Xiao-Jun Wang,Ke Cheng,Qiu-Yan Li","doi":"10.1039/d6dt01766e","DOIUrl":"https://doi.org/10.1039/d6dt01766e","url":null,"abstract":"CO2 is both an abundant, renewable C1 feedstock and a major greenhouse gas, making its efficient utilization a central challenge in sustainable chemistry. The carboxylative cyclization of propargylic amines with CO2 represents an inherently atom-economical route to oxazolidinones, an important class of heterocycles with broad applications in pharmaceuticals and fine chemicals. However, the development of robust catalysts that operate under mild conditions remains challenging. Herein, we report a mixed-valence Cu(I)/Cu(II) trinuclear cluster-based metal-organic framework (MOF), TPE2Pz-Cu, synthesized solvothermally from 1,1-bis(4-(1H-pyrazol-4-yl)phenyl)-2,2-diphenylethene (TPE2Pz) and Cu(NO3). The all-nitrogen coordination environment of the trinuclear copper clusters endows the framework with high thermal and chemical stability. Electron paramagnetic resonance (EPR) and X-ray photoelectron spectroscopy (XPS) analyses confirm the coexistence of Cu(I) and Cu(II) centers within the trinuclear cluster. With substoichiometric organic base 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU, 0.1 equiv.) as a co-catalyst, TPE2Pz-Cu mediates the carboxylative cyclization of propargylic amines at 60 oC under a CO2 balloon atmosphere, delivering oxazolidinones in yields of up to >99% with a turnover number (TON) of 220.8 and a turnover frequency (TOF) of 36.8 h⁻¹. The catalyst tolerates a broad substrate scope and retains >80% yield over five consecutive runs, reflecting its structural robustness. Mechanistic studies reveal that the Cu centers activate the alkynyl groups of propargylic amines whilst DBU facilitates deprotonation of the amino group, and the framework's high CO₂ affinity and ordered porous channels further facilitate CO₂ enrichment and pre-organization within the confined pore environment, thereby promoting the cyclization.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"34 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149248575","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}
Joonsik Kim,Tomoyuki Umeyama,Colin John Martin,Masaki Kawano,Yuki Wada,Takaya Matsumoto,Pavel M Usov
Copper(I) iodide frameworks featuring symmetric tetrahedral ligands enabled direct visualization of iodine sorption, including chemisorption and stepwise diffusion within a porous structure containing dimeric Cu2I2 units. The framework retained crystallinity during uptake, while diffraction and computational studies revealed directional I–I interactions and thermodynamically favored Cu2I2 reconstruction instead of simple pore filling.
{"title":"Allosteric reconstruction of copper(I) iodide dimers inside a metal-organic framework induced by adsorption of iodine","authors":"Joonsik Kim,Tomoyuki Umeyama,Colin John Martin,Masaki Kawano,Yuki Wada,Takaya Matsumoto,Pavel M Usov","doi":"10.1039/d6dt02248k","DOIUrl":"https://doi.org/10.1039/d6dt02248k","url":null,"abstract":"Copper(I) iodide frameworks featuring symmetric tetrahedral ligands enabled direct visualization of iodine sorption, including chemisorption and stepwise diffusion within a porous structure containing dimeric Cu2I2 units. The framework retained crystallinity during uptake, while diffraction and computational studies revealed directional I–I interactions and thermodynamically favored Cu2I2 reconstruction instead of simple pore filling.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"13 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241233","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}
Simple, homoleptic bismuth phosphanides Bi(PR2)3 (R2 = tBuCy, tBu2) have recently been introduced to the literature. Aiming to map the reactivity profiles of these interpnictogen compounds, reactions with elemental chalcogens (S8, Segrey, Te) and white phosphorus (P4) have been investigated. In these reactions, oxidation of the P atoms in the coordination sphere of bismuth are shown compete with phosphanyl (PR2) transfer from bismuth to the group 15/16 element. Phosphanyl transfer to P4 grants selective bottom-up access to the complex structural motif (PPR2)4 in a single step. Analytical methods applied in this work include heteronuclear NMR spectroscopy, high-resolution mass spectrometry, and single-crystal X-ray analyses.
{"title":"Bismuth Phosphanides Bi(PR) React with Chalcogens and P: Oxidation vs. Transfer of the Phosphanyl (PR) Unit","authors":"Sascha Reith,Felix Jakobi,Tobias Dunaj,Crispin Lichtenberg","doi":"10.1039/d6dt02381a","DOIUrl":"https://doi.org/10.1039/d6dt02381a","url":null,"abstract":"Simple, homoleptic bismuth phosphanides Bi(PR2)3 (R2 = tBuCy, tBu2) have recently been introduced to the literature. Aiming to map the reactivity profiles of these interpnictogen compounds, reactions with elemental chalcogens (S8, Segrey, Te) and white phosphorus (P4) have been investigated. In these reactions, oxidation of the P atoms in the coordination sphere of bismuth are shown compete with phosphanyl (PR2) transfer from bismuth to the group 15/16 element. Phosphanyl transfer to P4 grants selective bottom-up access to the complex structural motif (PPR2)4 in a single step. Analytical methods applied in this work include heteronuclear NMR spectroscopy, high-resolution mass spectrometry, and single-crystal X-ray analyses.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"2 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241234","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. N. Korzhova,A. A. Vorobyova,A. V. Fionov,O. S. Volkova,E. Kh. Lermontova,V. E. Gontcharenko,A. I. Shilov,T. Yu Glazunova
A silver complex in the +2 oxidation state, K3Ag(CF3COO)5(CF3COOH)(H2O)2 (I), and mixed +1/+2 oxidation-state silver complexes, K2AgIIAgI2(CF3COO)6(CF3COOH)(H2O) (II), Cs2AgIIAgI2(CF3COO)6 (III), K3AgIIAgI3(CF3COO)8(H2O) (IV), K3AgIIAgI3(CF3COO)8 (V), and Cs3AgIIAgI3(CF3COO)8 (VI) were synthesized by varying the reaction conditions between AgIAgIIIO2 and trifluoroacetic acid (CF3COOH, TFAH). Their crystal structures were determined by single-crystal X-ray diffraction analysis. The coordination environment of Ag(ii) in structures I–VI is close to square planar, and stabilization of Ag(ii) in these complexes is achieved through the incorporation of large monovalent cations—potassium or cesium. The paramagnetic behavior of compounds I–IV and VI was confirmed by magnetic measurements, including temperature-dependent magnetic susceptibility measurements in the range of 2–300 K and field-dependent magnetization measurements. The ESR properties of compounds I–VI were investigated at room temperature, with g-values in the range of 2.121–2.146. The thermal decomposition of compounds I–VI involves redox processes near 100 °C, leading to the formation of silver(i) complexes at an intermediate stage; complete decomposition occurs at 225–250 °C, yielding metallic silver and potassium fluoride (compounds I, II, IV, V) or cesium fluoride (compounds III, VI), respectively. The crystal structures of the silver(i) complexes MAg2(CF3COO)3(CF3COOH)4 (M = K (VII), M = Cs(VIII)) and Cs2Ag2(CF3COO)4(CF3COOH) (IX) were also determined by single-crystal X-ray diffraction analysis.
通过改变agagiiio2与三氟乙酸（CF3COOH， TFAH）的反应条件，合成了+2氧化态的银配合物K3Ag(CF3COO)5(CF3COOH)(H2O)2 (I)和+1/+2氧化态的混合银配合物K2AgIIAgI2(CF3COO)6(CF3COOH)(H2O) （II）、Cs2AgIIAgI2(CF3COO)6 （III）、K3AgIIAgI3(CF3COO)8(H2O) （IV）、K3AgIIAgI3(CF3COO)8(V)和Cs3AgIIAgI3(CF3COO)8 （VI）。通过单晶x射线衍射分析确定了它们的晶体结构。Ag（ii）在结构I-VI中的配位环境接近方形平面，Ag（ii）在这些配合物中的稳定是通过加入大的一价阳离子——钾或铯来实现的。化合物I-IV和VI的顺磁行为通过磁测量得到证实，包括2-300 K范围内的温度相关磁化率测量和场相关磁化强度测量。研究了化合物I-VI在室温下的ESR性能，g值在2.121 ~ 2.146之间。化合物i - vi的热分解涉及100°C附近的氧化还原过程，导致在中间阶段形成银(i)配合物；在225-250℃完全分解，分别产生金属银和氟化钾（化合物一、二、四、五）或氟化铯（化合物三、六）。用单晶x射线衍射分析确定了银(i)配合物MAg2(CF3COO)3(CF3COOH)4 (M = K （VII), M = Cs(VIII)）和Cs2Ag2(CF3COO)4(CF3COOH) （IX）的晶体结构。
{"title":"New insights into silver() chemistry: synthesis and properties of trifluoroacetate complexes","authors":"A. N. Korzhova,A. A. Vorobyova,A. V. Fionov,O. S. Volkova,E. Kh. Lermontova,V. E. Gontcharenko,A. I. Shilov,T. Yu Glazunova","doi":"10.1039/d6dt02195f","DOIUrl":"https://doi.org/10.1039/d6dt02195f","url":null,"abstract":"A silver complex in the +2 oxidation state, K3Ag(CF3COO)5(CF3COOH)(H2O)2 (I), and mixed +1/+2 oxidation-state silver complexes, K2AgIIAgI2(CF3COO)6(CF3COOH)(H2O) (II), Cs2AgIIAgI2(CF3COO)6 (III), K3AgIIAgI3(CF3COO)8(H2O) (IV), K3AgIIAgI3(CF3COO)8 (V), and Cs3AgIIAgI3(CF3COO)8 (VI) were synthesized by varying the reaction conditions between AgIAgIIIO2 and trifluoroacetic acid (CF3COOH, TFAH). Their crystal structures were determined by single-crystal X-ray diffraction analysis. The coordination environment of Ag(ii) in structures I–VI is close to square planar, and stabilization of Ag(ii) in these complexes is achieved through the incorporation of large monovalent cations—potassium or cesium. The paramagnetic behavior of compounds I–IV and VI was confirmed by magnetic measurements, including temperature-dependent magnetic susceptibility measurements in the range of 2–300 K and field-dependent magnetization measurements. The ESR properties of compounds I–VI were investigated at room temperature, with g-values in the range of 2.121–2.146. The thermal decomposition of compounds I–VI involves redox processes near 100 °C, leading to the formation of silver(i) complexes at an intermediate stage; complete decomposition occurs at 225–250 °C, yielding metallic silver and potassium fluoride (compounds I, II, IV, V) or cesium fluoride (compounds III, VI), respectively. The crystal structures of the silver(i) complexes MAg2(CF3COO)3(CF3COOH)4 (M = K (VII), M = Cs(VIII)) and Cs2Ag2(CF3COO)4(CF3COOH) (IX) were also determined by single-crystal X-ray diffraction analysis.","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":"2 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2026-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149241260","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：