4.2 Review

NMR-based analysis of structure of heteroleptic triple-decker (phthalocyaninato) (porphyrinato) lanthanides in solutions

期刊

MAGNETIC RESONANCE IN CHEMISTRY
卷 48, 期 7, 页码 505-515

出版社

WILEY-BLACKWELL
DOI: 10.1002/mrc.2612

关键词

H-1; crownphthalocyanine; porphyrin; lanthanide-induced shifts; lanthanide-induced relaxation; structural analysis; heteroleptic sandwich complexes

资金

  1. Russian Foundation for Basic Research [08-03-00835]
  2. Russian Academy of Science
  3. Russian Federation [MK-212.2010.3]
  4. European Research Association
  5. International Science and Technology Center [3718]

向作者/读者索取更多资源

A novel approach for the structural analysis of heteroleptic triple-decker (porphyrinato)(phthalocyaninato) lanthanides(III) in solutions is developed. The developed approach consists in molecular mechanics (MM+) optimization of the geometry of the complex taking into account the lanthanide-induced shift (LIS) datasets. LISs of the resonance peaks in H-1 NMR spectra of a series of symmetric complexes [An(4)P]Ln[(15C5)(4)Pc][An(4)P], where An(4)P(2-) is 5,10,15,20-tetrakis(4-methoxyphenyl)porphyrinatodianion, [(15C5)(4)Pc](2-) is 2,3,9,10,16,17,24,25-tetrakis(15-crown-5)phthalocyaninato-dianion and Ln = La, Ce, Pr, Nd, Sm, Eu, are analyzed. Analysis of LISs showed two sets of protons in the molecule with opposite signs of shift. Two-nuclei analysis of LISs testifies isostructurality of the whole series of investigated complexes in solution despite contraction of the lanthanide ions. Model-free separation of contact and dipolar contributions of LISs was performed with one-nucleus technique and did not show changes in contact and dipolar terms within the investigated series. MM+ optimization of the molecular structure allowed the interpretation of features of LIS for each particular group of protons. Parameterization of MM+-optimized model of molecule with values of structure-dependent dipolar contributions of LIS allows the development of the precise structural model of the triple-decker complex in solution. This approach allows the determination of the geometry and structure of the sandwich macrocyclic tetrapyrrolic complexes together with conformational analysis of flexible peripheral substituents in solutions. The developed method can be applied with minor modifications for the determination of structural parameters of other types of lanthanides(III) complexes with tetrapyrrolic ligands and also supramolecular systems based on them. Copyright (C) 2010 John Wiley & Sons, Ltd.

作者

我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。

评论

主要评分

4.2
评分不足

次要评分

新颖性
-
重要性
-
科学严谨性
-
评价这篇论文

推荐

暂无数据
暂无数据