Scholarlink

Abstract <p>Supramolecular lanthanide complexes with cucurbituril [{Eu<sub><i>x</i></sub>Pr<sub>1–<i>x</i></sub>(H<sub>2</sub>O)<sub>5</sub>(NO<sub>3</sub>)}<sub>2</sub>CB[6]](NO<sub>3</sub>)<sub>4</sub>·HNO<sub>3</sub> 6H<sub>2</sub>O (<i>x</i>&#xa0;=&#xa0;0.25, 0.5, 0.75, structural type <b>I</b>) are prepared. Keeping these compounds over CaCl<sub>2</sub> results in a phase transition which is caused by partial loss of water molecules and leads to the formation of [{Eu<sub><i>x</i> Pr1–<i>x</i></sub>(H<sub>2</sub>O)<sub>3</sub>(NO<sub>3</sub>)<sub>2</sub>}<sub>2</sub>CB[6]](NO<sub>3</sub>)<sub>2</sub>HNO<sub>3</sub> (structural type <b>II</b>). The <b>I</b> to <b>II</b> transition takes 24&#xa0;h and is reversible: when kept in water vapors for 2 h, <b>II</b> transforms completely into <b>I</b>. Luminescent properties of <b>I</b> and <b>II</b> are studied. Differences between the intensities of bands assigned to hypersensitive Eu-centered <sup>5</sup><i>D</i><sub>0</sub>&#xa0;→&#xa0;<sup>7</sup><i>F</i><sub>2</sub> transitions are due to the fact that coordination environments of the central atom are different and contain five (for <b>I</b>) and three (for <b>II</b>) aqualigands. Significantly higher quantum yield of <b>II</b> is due to the suppression of luminescence quenching by O–H vibrations.</p>

错误：搜索内容不能为空，请输入英文关键词
错误：关键词超出字数限制，请精简
高级检索

Influence of Hydrated Environment on Luminescent Properties of Pr(III) and Eu(III) Heterolanthanide Complexes with Cucurbituril

  • 期刊论文

  • 发表日期：

    2025年9月1日

查看全文
  • M. I. Rakhmanova,
  • T. S. Sukhikh,
  • E. A. Kovalenko

摘要

Abstract

Supramolecular lanthanide complexes with cucurbituril [{EuxPr1–x(H2O)5(NO3)}2CB[6]](NO3)4·HNO3 6H2O (x = 0.25, 0.5, 0.75, structural type I) are prepared. Keeping these compounds over CaCl2 results in a phase transition which is caused by partial loss of water molecules and leads to the formation of [{Eux Pr1–x(H2O)3(NO3)2}2CB[6]](NO3)2HNO3 (structural type II). The I to II transition takes 24 h and is reversible: when kept in water vapors for 2 h, II transforms completely into I. Luminescent properties of I and II are studied. Differences between the intensities of bands assigned to hypersensitive Eu-centered 5D0 → 7F2 transitions are due to the fact that coordination environments of the central atom are different and contain five (for I) and three (for II) aqualigands. Significantly higher quantum yield of II is due to the suppression of luminescence quenching by O–H vibrations.