{"title":"A few examples of cis trans isomerization in complexes involving the oxamide function","authors":"","doi":"10.1016/j.ica.2024.122319","DOIUrl":null,"url":null,"abstract":"<div><p>Synthesis of heterodinuclear 3d transition metal complexes in which two metal ions are introduced in equivalent coordination sites of a ligand is quite uncommon. We have previously shown that the application of the cis–trans isomerization of the oxamido group was able to furnish such a possibility. In the present paper we demonstrate that this synthetic pathway, relying on the possibility of changing the conformation (cis vs trans) of the oxamido group, can be extended to other ligands. Although we have not been able to characterize these complexes by structural determinations, FAB-MS, EPR and magnetic data do confirm the efficiency of this reaction pathway. We also demonstrate that the cis–trans isomerization of the oxamido group is not due to a particular property of the ion involved in the reaction. In fact, isomerization is governed by the basicity of the reaction medium. According to the reaction condition, it is possible to favor or not this phenomenon, and to increase the accessibility to a larger number of novel genuine complexes. But the oxophilic character of the lanthanide ions limits the use of this synthetic pathway because it impedes this isomerization. Eventually, the very weak magnetic interactions observed in these Cu-Gd complexes can be explained thanks to spin polarization.</p></div>","PeriodicalId":13599,"journal":{"name":"Inorganica Chimica Acta","volume":null,"pages":null},"PeriodicalIF":2.7000,"publicationDate":"2024-08-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Inorganica Chimica Acta","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0020169324004109","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, INORGANIC & NUCLEAR","Score":null,"Total":0}
引用次数: 0
Abstract
Synthesis of heterodinuclear 3d transition metal complexes in which two metal ions are introduced in equivalent coordination sites of a ligand is quite uncommon. We have previously shown that the application of the cis–trans isomerization of the oxamido group was able to furnish such a possibility. In the present paper we demonstrate that this synthetic pathway, relying on the possibility of changing the conformation (cis vs trans) of the oxamido group, can be extended to other ligands. Although we have not been able to characterize these complexes by structural determinations, FAB-MS, EPR and magnetic data do confirm the efficiency of this reaction pathway. We also demonstrate that the cis–trans isomerization of the oxamido group is not due to a particular property of the ion involved in the reaction. In fact, isomerization is governed by the basicity of the reaction medium. According to the reaction condition, it is possible to favor or not this phenomenon, and to increase the accessibility to a larger number of novel genuine complexes. But the oxophilic character of the lanthanide ions limits the use of this synthetic pathway because it impedes this isomerization. Eventually, the very weak magnetic interactions observed in these Cu-Gd complexes can be explained thanks to spin polarization.
在配体的等效配位上引入两个金属离子的异核 3d 过渡金属配合物的合成并不常见。我们之前已经证明,应用草酰胺基团的顺反异构化可以提供这种可能性。在本文中,我们证明了这种依靠改变草酰胺基团构象(顺式与反式)的合成途径可以扩展到其他配体。虽然我们无法通过结构测定来确定这些复合物的特征,但 FAB-MS、EPR 和磁性数据确实证实了这种反应途径的效率。我们还证明,草酰胺基团的顺反异构并不是由于参与反应的离子的特定性质造成的。事实上,异构化受反应介质碱性的影响。根据反应条件的不同,这种现象有可能发生,也有可能不发生,从而产生更多新的真正络合物。但镧系元素离子的亲氧化特性会阻碍这种异构化,从而限制了这种合成途径的使用。最终,在这些铜钆配合物中观察到的非常微弱的磁相互作用可以用自旋极化来解释。
期刊介绍:
Inorganica Chimica Acta is an established international forum for all aspects of advanced Inorganic Chemistry. Original papers of high scientific level and interest are published in the form of Articles and Reviews.
Topics covered include:
• chemistry of the main group elements and the d- and f-block metals, including the synthesis, characterization and reactivity of coordination, organometallic, biomimetic, supramolecular coordination compounds, including associated computational studies;
• synthesis, physico-chemical properties, applications of molecule-based nano-scaled clusters and nanomaterials designed using the principles of coordination chemistry, as well as coordination polymers (CPs), metal-organic frameworks (MOFs), metal-organic polyhedra (MPOs);
• reaction mechanisms and physico-chemical investigations computational studies of metalloenzymes and their models;
• applications of inorganic compounds, metallodrugs and molecule-based materials.
Papers composed primarily of structural reports will typically not be considered for publication.