Sage Journals: Discover world-class research

Abstract

Different types of organic doublet radicals have been investigated in isotropic, nematic, and smectic phases of liquid crystals by performing electron nuclear double resonance (ENDOR), general TRIPLE and special TRIPLE experiments. For this purpose phenalenyls (perinaphthenyls), galvinoxyl, tetra-tert.-butylcarbazolyl, and bis(biphenylenyl)propenyl radicals have been chosen including some partially deuterated and ¹³C-labeled compounds. Anisotropic hyperfine interactions and deuterium quadrupole couplings could be determined. Smectic A phases have proved to be advantageous as compared to nematic phases in these studies. Detailed information about the orientation of the radicals within the liquid-crystalline solvent and about the conformations of the radicals could be obtained.

Keywords

ENDOR spectroscopy Free radicals Liquid crystals nematic and smectic A phases of Anisotropic hyperfine interaction Quadrupole couplings

Get full access to this article

View all access options for this article.

References

Atherton

N. M.

, Electron Spin Resonance (Ellis Horwood, Chichester, 1973).

Kevan

and Kispert

L. D.

, Electron Spin Double Resonance Spectroscopy (Wiley, New York, 1976).

Möbius

and Biehl

, in Multiple Electron Resonance Spectroscopy, Dorio

M. M.

and Freed

J. H.

, Eds. (Plenum, New York, 1979).

Biehl

Hass

Ch.

Kurreck

Lubitz

, and Oestreich

, Tetrahedron 34, 419 (1978).

Broser

Kurreck

Oestreich-Janzen

Schlömp

Fey

H.-J.

, and Kirste

, Tetrahedron 35, 1159 (1979).

Kuhn

Fischer

Neugebauer

F. A.

, and Fischer

, Liebigs Ann. Chem. 654, 64 (1962).

Neugebauer

F. A.

Fischer

Bamberger

, and Smith

H. O.

, Chem. Ber. 105, 2694 (1972).

Luckhurst

G. R.

and Poupko

, Mol. Phys. 29, 1293 (1975).

Luckhurst

G. R.

, in Liquid Crystals and Plastic Crystals, Gray

G. W.

and Winsor

P. A.

, Eds. (Ellis Horwood, Chichester, 1974), Vol. 2, Chap. 7.

10.

Lin

W.-J.

and Freed

J. H.

, J. Phys. Chem. 83, 379 (1979).

11.

Fey

H.-J.

Kurreck

, and Lubitz

, Tetrahedron 35, 905 (1979).

12.

Falle

H. R.

and Luckhurst

G. R.

, J. Mag. Res. 3, 161 (1970).

13.

Kirste

Kurreck

Lubitz

, and Zimmermann

, J. Am. Chem. Soc. 102, 817 (1980).

14.

Glarum

S. H.

and Marshall

J. H.

, J. Chem. Phys. 44, 2884 (1966).

15.

Biehl

Lubitz

Möbius

, and Plato

, J. Chem. Phys. 66, 2074 (1977).

16.

Kirste

Kurreck

Fey

H.-J.

Hass

Ch.

, and Schlömp

, J. Am. Chem. Soc. 101, 7457 (1979).

17.

Allendoerfer

R. D.

, Chem. Phys. Lett. 17, 172 (1972).

18.

Kirste

, Chem. Phys. Lett. 64, 63 (1979).

Electron Nuclear Double Resonance (ENDOR) Investigations of Organic Doublet Radicals in the Nematic and Smectic Phase of Liquid Crystals

Abstract

Keywords

Get full access to this article

References