Elena Grattoni, Fabio Travagin, Ferenc Kálmán, Zsolt Baranyai, Roberto Negri, Fabio Carniato, Giovanni B. Giovenzana, Carlos Platas-Iglesias and Mauro Botta
{"title":"评估结构相关的无环配体 OBETA、EHDTA 和 EGTA 对稳定 Mn²⁺ 复合物形成的作用","authors":"Elena Grattoni, Fabio Travagin, Ferenc Kálmán, Zsolt Baranyai, Roberto Negri, Fabio Carniato, Giovanni B. Giovenzana, Carlos Platas-Iglesias and Mauro Botta","doi":"10.1039/D4DT02761B","DOIUrl":null,"url":null,"abstract":"<p >In recent years, significant research efforts have been dedicated to finding efficient and safe alternatives to the currently used gadolinium (Gd)-based MRI contrast agents. Among the most explored alternatives are paramagnetic chelates of the Earth-abundant Mn<small><sup>2+</sup></small>, which form a prominent class of metal complexes. The design of Mn<small><sup>2+</sup></small> complexes with enhanced relaxation properties and improved safety profiles hinges on a delicate balance between thermodynamic and kinetic stability, as well as the presence of coordinated water molecules. In this study, we present a comprehensive investigation into the coordination chemistry of three structurally related polyetheraminocarboxylic chelating agents. Our aim is to elucidate the structural features, paramagnetic properties, and thermodynamic and kinetic inertness of the corresponding Mn<small><sup>2+</sup></small> complexes. The most significant finding is the considerable difference in the dissociation rates of the complexes, with the octadentate <strong>EGTA</strong> complex being the most labile. The observed dissociation rates correlate well with the nitrogen inversion dynamics, as assessed through NMR spectral analysis of the analogous Zn<small><sup>2+</sup></small> complexes.</p>","PeriodicalId":71,"journal":{"name":"Dalton Transactions","volume":" 1","pages":" 376-388"},"PeriodicalIF":3.5000,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/dt/d4dt02761b?page=search","citationCount":"0","resultStr":"{\"title\":\"Evaluation of structurally related acyclic ligands OBETA, EHDTA, and EGTA for stable Mn2+ complex formation†\",\"authors\":\"Elena Grattoni, Fabio Travagin, Ferenc Kálmán, Zsolt Baranyai, Roberto Negri, Fabio Carniato, Giovanni B. Giovenzana, Carlos Platas-Iglesias and Mauro Botta\",\"doi\":\"10.1039/D4DT02761B\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<p >In recent years, significant research efforts have been dedicated to finding efficient and safe alternatives to the currently used gadolinium (Gd)-based MRI contrast agents. Among the most explored alternatives are paramagnetic chelates of the Earth-abundant Mn<small><sup>2+</sup></small>, which form a prominent class of metal complexes. The design of Mn<small><sup>2+</sup></small> complexes with enhanced relaxation properties and improved safety profiles hinges on a delicate balance between thermodynamic and kinetic stability, as well as the presence of coordinated water molecules. In this study, we present a comprehensive investigation into the coordination chemistry of three structurally related polyetheraminocarboxylic chelating agents. Our aim is to elucidate the structural features, paramagnetic properties, and thermodynamic and kinetic inertness of the corresponding Mn<small><sup>2+</sup></small> complexes. The most significant finding is the considerable difference in the dissociation rates of the complexes, with the octadentate <strong>EGTA</strong> complex being the most labile. The observed dissociation rates correlate well with the nitrogen inversion dynamics, as assessed through NMR spectral analysis of the analogous Zn<small><sup>2+</sup></small> complexes.</p>\",\"PeriodicalId\":71,\"journal\":{\"name\":\"Dalton Transactions\",\"volume\":\" 1\",\"pages\":\" 376-388\"},\"PeriodicalIF\":3.5000,\"publicationDate\":\"2024-11-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"https://pubs.rsc.org/en/content/articlepdf/2025/dt/d4dt02761b?page=search\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Dalton Transactions\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://pubs.rsc.org/en/content/articlelanding/2025/dt/d4dt02761b\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, INORGANIC & NUCLEAR\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Dalton Transactions","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2025/dt/d4dt02761b","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
Evaluation of structurally related acyclic ligands OBETA, EHDTA, and EGTA for stable Mn2+ complex formation†
In recent years, significant research efforts have been dedicated to finding efficient and safe alternatives to the currently used gadolinium (Gd)-based MRI contrast agents. Among the most explored alternatives are paramagnetic chelates of the Earth-abundant Mn2+, which form a prominent class of metal complexes. The design of Mn2+ complexes with enhanced relaxation properties and improved safety profiles hinges on a delicate balance between thermodynamic and kinetic stability, as well as the presence of coordinated water molecules. In this study, we present a comprehensive investigation into the coordination chemistry of three structurally related polyetheraminocarboxylic chelating agents. Our aim is to elucidate the structural features, paramagnetic properties, and thermodynamic and kinetic inertness of the corresponding Mn2+ complexes. The most significant finding is the considerable difference in the dissociation rates of the complexes, with the octadentate EGTA complex being the most labile. The observed dissociation rates correlate well with the nitrogen inversion dynamics, as assessed through NMR spectral analysis of the analogous Zn2+ complexes.
期刊介绍:
Dalton Transactions is a journal for all areas of inorganic chemistry, which encompasses the organometallic, bioinorganic and materials chemistry of the elements, with applications including synthesis, catalysis, energy conversion/storage, electrical devices and medicine. Dalton Transactions welcomes high-quality, original submissions in all of these areas and more, where the advancement of knowledge in inorganic chemistry is significant.