Inclusion complexes of cyclodextrins with biradicals linked by a polyether chain - an EPR study

Gabriela Ionita; Viorica Meltzer; Elena Pincu; Victor Chechik

doi:10.1039/b704112h

Inclusion complexes of cyclodextrins with biradicals linked by a polyether chain - an EPR study

Gabriela Ionita, Viorica Meltzer, Elena Pincu, Victor Chechik

Chemistry

Research output: Contribution to journal › Article › peer-review

Abstract

Complexation of beta-cyclodextrin with flexible nitroxide biradicals linked by a polyethylene glycol chain was monitored by EPR spectroscopy. The EPR spectra of the uncomplexed biradicals show an exchange interaction due to the flexibility of the polyethylene glycol chain. Complexation with cyclodextrin leads to the disappearance of the exchange interaction in the EPR spectra. The complexation can be reversed by the addition of competing guests (e.g., adamantane derivatives). At high concentration, the inclusion complexes precipitate, and differential scanning calorimetry (DSC) of the precipitates proved the formation of complexes. Elemental analysis data revealed that the complexes contain several cyclodextrin units per biradical but that the composition was not stoichiometric.

Original language	English
Pages (from-to)	1910-1914
Number of pages	5
Journal	Organic and Biomolecular Chemistry
Volume	5
Issue number	12
DOIs	https://doi.org/10.1039/b704112h
Publication status	Published - 2007

Keywords

ELECTRON-SPIN-RESONANCE
NUCLEAR DOUBLE-RESONANCE
BETA-CYCLODEXTRIN
NITROXIDE RADICALS
LABELED CYCLODEXTRINS
ALPHA-CYCLODEXTRIN
BIMODAL INCLUSION
PROBE
WATER

Access to Document

10.1039/b704112h

Cite this

@article{874d80c520fc4269b8962bafd3d21358,

title = "Inclusion complexes of cyclodextrins with biradicals linked by a polyether chain - an EPR study",

abstract = "Complexation of beta-cyclodextrin with flexible nitroxide biradicals linked by a polyethylene glycol chain was monitored by EPR spectroscopy. The EPR spectra of the uncomplexed biradicals show an exchange interaction due to the flexibility of the polyethylene glycol chain. Complexation with cyclodextrin leads to the disappearance of the exchange interaction in the EPR spectra. The complexation can be reversed by the addition of competing guests (e.g., adamantane derivatives). At high concentration, the inclusion complexes precipitate, and differential scanning calorimetry (DSC) of the precipitates proved the formation of complexes. Elemental analysis data revealed that the complexes contain several cyclodextrin units per biradical but that the composition was not stoichiometric.",

keywords = "ELECTRON-SPIN-RESONANCE, NUCLEAR DOUBLE-RESONANCE, BETA-CYCLODEXTRIN, NITROXIDE RADICALS, LABELED CYCLODEXTRINS, ALPHA-CYCLODEXTRIN, BIMODAL INCLUSION, PROBE, WATER",

author = "Gabriela Ionita and Viorica Meltzer and Elena Pincu and Victor Chechik",

year = "2007",

doi = "10.1039/b704112h",

language = "English",

volume = "5",

pages = "1910--1914",

journal = "Organic and Biomolecular Chemistry",

issn = "1477-0520",

publisher = "The Royal Society of Chemistry",

number = "12",

}

TY - JOUR

T1 - Inclusion complexes of cyclodextrins with biradicals linked by a polyether chain - an EPR study

AU - Ionita, Gabriela

AU - Meltzer, Viorica

AU - Pincu, Elena

AU - Chechik, Victor

PY - 2007

Y1 - 2007

N2 - Complexation of beta-cyclodextrin with flexible nitroxide biradicals linked by a polyethylene glycol chain was monitored by EPR spectroscopy. The EPR spectra of the uncomplexed biradicals show an exchange interaction due to the flexibility of the polyethylene glycol chain. Complexation with cyclodextrin leads to the disappearance of the exchange interaction in the EPR spectra. The complexation can be reversed by the addition of competing guests (e.g., adamantane derivatives). At high concentration, the inclusion complexes precipitate, and differential scanning calorimetry (DSC) of the precipitates proved the formation of complexes. Elemental analysis data revealed that the complexes contain several cyclodextrin units per biradical but that the composition was not stoichiometric.

AB - Complexation of beta-cyclodextrin with flexible nitroxide biradicals linked by a polyethylene glycol chain was monitored by EPR spectroscopy. The EPR spectra of the uncomplexed biradicals show an exchange interaction due to the flexibility of the polyethylene glycol chain. Complexation with cyclodextrin leads to the disappearance of the exchange interaction in the EPR spectra. The complexation can be reversed by the addition of competing guests (e.g., adamantane derivatives). At high concentration, the inclusion complexes precipitate, and differential scanning calorimetry (DSC) of the precipitates proved the formation of complexes. Elemental analysis data revealed that the complexes contain several cyclodextrin units per biradical but that the composition was not stoichiometric.

KW - ELECTRON-SPIN-RESONANCE

KW - NUCLEAR DOUBLE-RESONANCE

KW - BETA-CYCLODEXTRIN

KW - NITROXIDE RADICALS

KW - LABELED CYCLODEXTRINS

KW - ALPHA-CYCLODEXTRIN

KW - BIMODAL INCLUSION

KW - PROBE

KW - WATER

U2 - 10.1039/b704112h

DO - 10.1039/b704112h

M3 - Article

SN - 1477-0520

VL - 5

SP - 1910

EP - 1914

JO - Organic and Biomolecular Chemistry

JF - Organic and Biomolecular Chemistry

IS - 12

ER -