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Title: Structural investigation into the steric control of polyether complexation in the lanthanide series: Macrocyclic 18-crown-6 versus acyclic pentaethylene glycol

The complexation reactions of MCl[sub 3][center dot]nH[sub 2]O (M = Y, La-Pr, Sm-Lu) with pentaethylene glycol (EO5) and MCl[sub 3][center dot]nH[sub 2]O (M = La, Ce, Pr, Eu, Gd) with 18-crown-6 in 1:1 molar ratios in 3:1 CH[sub 3]CN:CH[sub 3]OH were investigated. X-ray structural analysis of 21 crystalline complexes were carried out. Comparison of all the crystalline complexes studied reveals that polyethylene glycols exhibit a helical wrapping pattern around the lanthanide ions, while the crown ethers attempt to fold around these cations. This feature of polyether complexation of the lanthanide(III) chlorides may be responsible for the ready isolation of EO5 complexes for all lanthanides and the lack of direct coordination of 18-crown-6 past M = Tb in normal 1:1 complexation reactions.
Authors:
; ; ; ;  [1]
  1. (Northern Illinois Univ., DeKalb, IL (United States))
Publication Date:
OSTI Identifier:
5088593
Resource Type:
Journal Article
Resource Relation:
Journal Name: Inorganic Chemistry; (United States); Journal Volume: 32:16
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; RARE EARTH COMPLEXES; CRYSTAL STRUCTURE; YTTRIUM COMPLEXES; CHELATING AGENTS; CROWN ETHERS; HYDRATES; POLYETHYLENE GLYCOLS; X-RAY DIFFRACTION; ALCOHOLS; COHERENT SCATTERING; COMPLEXES; DIFFRACTION; ETHERS; GLYCOLS; HYDROXY COMPOUNDS; ORGANIC COMPOUNDS; ORGANIC OXYGEN COMPOUNDS; ORGANIC POLYMERS; POLYMERS; SCATTERING; TRANSITION ELEMENT COMPLEXES 400201* -- Chemical & Physicochemical Properties