Thermotropic Behavior of Lipophilic Derivatized [60]Fullerenes Studied by Deuterium NMR, X-ray Diffraction, and Microcalorimetry

Michael Hetzer, Thomas Gutberiet, Michael F Brown, Xavier Camps, Otto Vostrowsky, Hubert Schönberger, Andreas Hirsch, Thomas M. Bayerl

Research output: Contribution to journalArticle

28 Citations (Scopus)

Abstract

The dynamics, structure, and thermotropic behavior of a new class of lipophilic [60]fullerene (C60) derivatives, so-called lipo-fullerenes, have been studied by differential scanning calorimetry (DSC), deuterium nuclear magnetic resonance (2H NMR), and X-ray scattering. The lipo-fullerene studied consists of six pairs of perdeuterated C18 alkyl chains as substituents of six covalently attached methylene groups in octahedral sites. The symmetry of this highly symmetrical hexamethanofullerene is Th We find drastic changes of the molecular arrangement of the lipo-fullerenes induced by temperature. Heating the sample from 20 to 70 °C causes it to undergo two major structural transitions. At 55 °C we observe an exothermic transition from a low-temperature, hard sphere-like packing state of the molecules, with separation distances (6.1 nm) slightly above the maximum diameter of the molecules, to a condensed one. This latter state involves partial intercalation (interdigitation) of the alkyl chains belonging to adjacent molecules and is preceded by partial melting of the chains to accommodate sterically for the (exothermic) interdigitation. The latter allows denser packing with an average separation distance of 4.8 nm. At a temperature of 64 °C, an endothermic melting transition from the interdigitated to a viscous fluidlike state is observed, with an average separation distance of 2.8 nm. Cooling the sample from 70 °C causes a direct transition from the fluid into the low-temperature state with no interdigitation of the chains.

Original languageEnglish (US)
Pages (from-to)637-642
Number of pages6
JournalJournal of Physical Chemistry A
Volume103
Issue number5
StatePublished - 1999

Fingerprint

Deuterium
Fullerenes
fullerenes
deuterium
Nuclear magnetic resonance
X ray diffraction
nuclear magnetic resonance
diffraction
Molecules
Melting
x rays
melting
molecules
Temperature
causes
Intercalation
X ray scattering
methylene
intercalation
Differential scanning calorimetry

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry

Cite this

Hetzer, M., Gutberiet, T., Brown, M. F., Camps, X., Vostrowsky, O., Schönberger, H., ... Bayerl, T. M. (1999). Thermotropic Behavior of Lipophilic Derivatized [60]Fullerenes Studied by Deuterium NMR, X-ray Diffraction, and Microcalorimetry. Journal of Physical Chemistry A, 103(5), 637-642.

Thermotropic Behavior of Lipophilic Derivatized [60]Fullerenes Studied by Deuterium NMR, X-ray Diffraction, and Microcalorimetry. / Hetzer, Michael; Gutberiet, Thomas; Brown, Michael F; Camps, Xavier; Vostrowsky, Otto; Schönberger, Hubert; Hirsch, Andreas; Bayerl, Thomas M.

In: Journal of Physical Chemistry A, Vol. 103, No. 5, 1999, p. 637-642.

Research output: Contribution to journalArticle

Hetzer, M, Gutberiet, T, Brown, MF, Camps, X, Vostrowsky, O, Schönberger, H, Hirsch, A & Bayerl, TM 1999, 'Thermotropic Behavior of Lipophilic Derivatized [60]Fullerenes Studied by Deuterium NMR, X-ray Diffraction, and Microcalorimetry', Journal of Physical Chemistry A, vol. 103, no. 5, pp. 637-642.
Hetzer, Michael ; Gutberiet, Thomas ; Brown, Michael F ; Camps, Xavier ; Vostrowsky, Otto ; Schönberger, Hubert ; Hirsch, Andreas ; Bayerl, Thomas M. / Thermotropic Behavior of Lipophilic Derivatized [60]Fullerenes Studied by Deuterium NMR, X-ray Diffraction, and Microcalorimetry. In: Journal of Physical Chemistry A. 1999 ; Vol. 103, No. 5. pp. 637-642.
@article{7c4ac05296a1481d81cc614d2b61bf04,
title = "Thermotropic Behavior of Lipophilic Derivatized [60]Fullerenes Studied by Deuterium NMR, X-ray Diffraction, and Microcalorimetry",
abstract = "The dynamics, structure, and thermotropic behavior of a new class of lipophilic [60]fullerene (C60) derivatives, so-called lipo-fullerenes, have been studied by differential scanning calorimetry (DSC), deuterium nuclear magnetic resonance (2H NMR), and X-ray scattering. The lipo-fullerene studied consists of six pairs of perdeuterated C18 alkyl chains as substituents of six covalently attached methylene groups in octahedral sites. The symmetry of this highly symmetrical hexamethanofullerene is Th We find drastic changes of the molecular arrangement of the lipo-fullerenes induced by temperature. Heating the sample from 20 to 70 °C causes it to undergo two major structural transitions. At 55 °C we observe an exothermic transition from a low-temperature, hard sphere-like packing state of the molecules, with separation distances (6.1 nm) slightly above the maximum diameter of the molecules, to a condensed one. This latter state involves partial intercalation (interdigitation) of the alkyl chains belonging to adjacent molecules and is preceded by partial melting of the chains to accommodate sterically for the (exothermic) interdigitation. The latter allows denser packing with an average separation distance of 4.8 nm. At a temperature of 64 °C, an endothermic melting transition from the interdigitated to a viscous fluidlike state is observed, with an average separation distance of 2.8 nm. Cooling the sample from 70 °C causes a direct transition from the fluid into the low-temperature state with no interdigitation of the chains.",
author = "Michael Hetzer and Thomas Gutberiet and Brown, {Michael F} and Xavier Camps and Otto Vostrowsky and Hubert Sch{\"o}nberger and Andreas Hirsch and Bayerl, {Thomas M.}",
year = "1999",
language = "English (US)",
volume = "103",
pages = "637--642",
journal = "Journal of Physical Chemistry A",
issn = "1089-5639",
publisher = "American Chemical Society",
number = "5",

}

TY - JOUR

T1 - Thermotropic Behavior of Lipophilic Derivatized [60]Fullerenes Studied by Deuterium NMR, X-ray Diffraction, and Microcalorimetry

AU - Hetzer, Michael

AU - Gutberiet, Thomas

AU - Brown, Michael F

AU - Camps, Xavier

AU - Vostrowsky, Otto

AU - Schönberger, Hubert

AU - Hirsch, Andreas

AU - Bayerl, Thomas M.

PY - 1999

Y1 - 1999

N2 - The dynamics, structure, and thermotropic behavior of a new class of lipophilic [60]fullerene (C60) derivatives, so-called lipo-fullerenes, have been studied by differential scanning calorimetry (DSC), deuterium nuclear magnetic resonance (2H NMR), and X-ray scattering. The lipo-fullerene studied consists of six pairs of perdeuterated C18 alkyl chains as substituents of six covalently attached methylene groups in octahedral sites. The symmetry of this highly symmetrical hexamethanofullerene is Th We find drastic changes of the molecular arrangement of the lipo-fullerenes induced by temperature. Heating the sample from 20 to 70 °C causes it to undergo two major structural transitions. At 55 °C we observe an exothermic transition from a low-temperature, hard sphere-like packing state of the molecules, with separation distances (6.1 nm) slightly above the maximum diameter of the molecules, to a condensed one. This latter state involves partial intercalation (interdigitation) of the alkyl chains belonging to adjacent molecules and is preceded by partial melting of the chains to accommodate sterically for the (exothermic) interdigitation. The latter allows denser packing with an average separation distance of 4.8 nm. At a temperature of 64 °C, an endothermic melting transition from the interdigitated to a viscous fluidlike state is observed, with an average separation distance of 2.8 nm. Cooling the sample from 70 °C causes a direct transition from the fluid into the low-temperature state with no interdigitation of the chains.

AB - The dynamics, structure, and thermotropic behavior of a new class of lipophilic [60]fullerene (C60) derivatives, so-called lipo-fullerenes, have been studied by differential scanning calorimetry (DSC), deuterium nuclear magnetic resonance (2H NMR), and X-ray scattering. The lipo-fullerene studied consists of six pairs of perdeuterated C18 alkyl chains as substituents of six covalently attached methylene groups in octahedral sites. The symmetry of this highly symmetrical hexamethanofullerene is Th We find drastic changes of the molecular arrangement of the lipo-fullerenes induced by temperature. Heating the sample from 20 to 70 °C causes it to undergo two major structural transitions. At 55 °C we observe an exothermic transition from a low-temperature, hard sphere-like packing state of the molecules, with separation distances (6.1 nm) slightly above the maximum diameter of the molecules, to a condensed one. This latter state involves partial intercalation (interdigitation) of the alkyl chains belonging to adjacent molecules and is preceded by partial melting of the chains to accommodate sterically for the (exothermic) interdigitation. The latter allows denser packing with an average separation distance of 4.8 nm. At a temperature of 64 °C, an endothermic melting transition from the interdigitated to a viscous fluidlike state is observed, with an average separation distance of 2.8 nm. Cooling the sample from 70 °C causes a direct transition from the fluid into the low-temperature state with no interdigitation of the chains.

UR - http://www.scopus.com/inward/record.url?scp=0033521779&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033521779&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0033521779

VL - 103

SP - 637

EP - 642

JO - Journal of Physical Chemistry A

JF - Journal of Physical Chemistry A

SN - 1089-5639

IS - 5

ER -