Qing Ma, Sen Yin, Ziye Song, Ting Gao, Pengfei Yan, Yanyan Zhou and Hongfeng Li
{"title":"Unusual solvent-regulated inversion of a metal stereocenter in an enantiopure Eu2L4 helicate: a new strategy for CPL inversion†","authors":"Qing Ma, Sen Yin, Ziye Song, Ting Gao, Pengfei Yan, Yanyan Zhou and Hongfeng Li","doi":"10.1039/D4QI02276A","DOIUrl":null,"url":null,"abstract":"<p >Developing artificial metal helicates with stimuli-responsive helicity inversion is a significant challenge in functional supramolecular chemistry. However, most reported helicity inversions are based on the synchronous transformation of <em>P</em>/<em>M</em> conformation and the metal center's Δ/Λ configuration, requiring the overcoming of substantial energy barriers. Herein, we report the first example of Δ/Λ configurational inversion of metal centers independent of the <em>P</em>/<em>M</em> conformational conversion. The helicate (NMe<small><sub>4</sub></small>)<small><sub>2</sub></small>[Eu<small><sub>2</sub></small>(<strong>L<small><sup>R</sup></small></strong>)<small><sub>4</sub></small>], maintaining a constant <em>P</em> helical conformation, undergoes a local metal center configurational conversion from ΛΛ-(NMe<small><sub>4</sub></small>)<small><sub>2</sub></small>[Eu<small><sub>2</sub></small>(<strong>L<small><sup>R</sup></small></strong>)<small><sub>4</sub></small>] → ΔΛ-(NMe<small><sub>4</sub></small>)<small><sub>2</sub></small>[Eu<small><sub>2</sub></small>(<strong>L<small><sup>R</sup></small></strong>)<small><sub>4</sub></small>] → ΔΔ-(NMe<small><sub>4</sub></small>)<small><sub>2</sub></small>[Eu<small><sub>2</sub></small>(<strong>L<small><sup>R</sup></small></strong>)<small><sub>4</sub></small>] upon increasing the content of CHCl<small><sub>3</sub></small> in CH<small><sub>3</sub></small>CN. Associated with the conversion, the inversion of circularly polarized luminescence (CPL) activity took place with the luminescence dissymmetry factor (<em>g</em><small><sub>lum</sub></small> value) changing from −0.23 to +0.44. The understanding thus gained as to the solvent's impact on local chirality inversion enabled the design of CPL optical switches or sensors based on lanthanide helicates.</p>","PeriodicalId":6,"journal":{"name":"ACS Applied Nano Materials","volume":null,"pages":null},"PeriodicalIF":5.3000,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"ACS Applied Nano Materials","FirstCategoryId":"92","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2024/qi/d4qi02276a","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
引用次数: 0
Abstract
Developing artificial metal helicates with stimuli-responsive helicity inversion is a significant challenge in functional supramolecular chemistry. However, most reported helicity inversions are based on the synchronous transformation of P/M conformation and the metal center's Δ/Λ configuration, requiring the overcoming of substantial energy barriers. Herein, we report the first example of Δ/Λ configurational inversion of metal centers independent of the P/M conformational conversion. The helicate (NMe4)2[Eu2(LR)4], maintaining a constant P helical conformation, undergoes a local metal center configurational conversion from ΛΛ-(NMe4)2[Eu2(LR)4] → ΔΛ-(NMe4)2[Eu2(LR)4] → ΔΔ-(NMe4)2[Eu2(LR)4] upon increasing the content of CHCl3 in CH3CN. Associated with the conversion, the inversion of circularly polarized luminescence (CPL) activity took place with the luminescence dissymmetry factor (glum value) changing from −0.23 to +0.44. The understanding thus gained as to the solvent's impact on local chirality inversion enabled the design of CPL optical switches or sensors based on lanthanide helicates.
期刊介绍:
ACS Applied Nano Materials is an interdisciplinary journal publishing original research covering all aspects of engineering, chemistry, physics and biology relevant to applications of nanomaterials. The journal is devoted to reports of new and original experimental and theoretical research of an applied nature that integrate knowledge in the areas of materials, engineering, physics, bioscience, and chemistry into important applications of nanomaterials.