According to the damped quantum rotation (DQR) theory, hindered rotation of methyl groups, evidenced in nuclear magnetic resonance (NMR) line shapes, is a nonclassical process. It comprises a number of quantum-rate processes measured by two different quantum-rate constants. The classical jump model employing only one rate constant is reproduced if these quantum constants happen to be equal. The values of their ratio, or the nonclassicallity coefficient, determined hitherto from NMR spectra of single crystals and solutions range from about 1.20 to 1.30 in the latter case to above 5.0 in the former, with the value of 1 corresponding to the jump model. Presently, first systematic investigations of the DQR effects in wide-line NMR spectra of a powder sample are reported. For 1,1,1-triphenylethane deuterated in the aromatic positions, the relevant line-shape effects were monitored in the range 99–121 K. The values of the nonclassicality coefficient dropping from 2.7 to 1.7 were evaluated in line shape fits to the experimental powder spectra from the range 99–108 K. At these temperatures, the fits with the conventional line-shape model are visibly inferior to the DQR fits. Using a theoretical model reported earlier, a semiquantitative interpretation of the DQR parameters evaluated from the spectra is given. It is shown that the DQR effects as such can be detected in wide-line NMR spectra of powdered samples, which are relatively facile to measure. However, a fully quantitative picture of these effects can only be obtained from the much more demanding experiments on single crystals.

1.
F.
Apaydin
and
S.
Clough
,
J. Phys. C: Solid State Phys.
1
,
932
(
1968
).
2.
T.
Bernhard
and
U.
Haeberlen
,
Chem. Phys. Lett.
186
,
307
(
1991
).
3.
A.
Detken
,
P.
Focke
,
H.
Zimmermann
,
U.
Haeberlen
,
Z.
Olejniczak
, and
Z. T.
Lalowicz
,
Z. Naturforsch., A: Phys. Sci.
50
,
95
(
1995
).
4.
E. M.
Hiller
and
R. A.
Harris
,
J. Chem. Phys.
98
,
2077
(
1993
).
5.
A.
Detken
,
H.
Zimmermann
, and
U.
Haeberlen
,
Mol. Phys.
96
,
927
(
1999
).
6.
P.
Gutsche
,
M.
Rinsdorf
,
H.
Zimmermann
,
H.
Schmitt
, and
U.
Haeberlen
,
Solid State Nucl. Magn. Reson.
25
,
227
(
2004
).
7.
S.
Szymański
,
J. Chem. Phys.
111
,
288
(
1999
).
8.
S.
Clough
,
NMR. Basic Principles and Progress
(
Springer-Verlag
,
1976
), Vol. 13, pp.
113
.
9.
S.
Alexander
,
J. Chem. Phys.
37
,
974
(
1962
).
10.
D. A.
Kleier
and
G.
Binsch
,
J. Magn. Reson.
3
,
146
(
1970
).
11.
S.
Szymański
,
Z.
Olejniczak
,
A.
Detken
, and
U.
Haeberlen
,
J. Magn. Reson.
148
,
277
(
2001
).
12.
P.
Gutsche
,
H.
Schmitt
,
U.
Haeberlen
,
T.
Ratajczyk
, and
S.
Szymański
,
ChemPhysChem
7
,
886
(
2006
).
13.
S.
Szymański
,
Z.
Olejniczak
, and
U.
Haeberlen
,
Physica B
226
,
161
(
1996
).
14.
P.
Bernatowicz
and
S.
Szymański
,
Phys. Rev. Lett.
89
,
023004
(
2002
).
15.
I.
Czerski
,
P.
Bernatowicz
,
J.
Jazwinski
, and
S.
Szymański
,
J. Chem. Phys.
118
,
7157
(
2003
).
16.
P.
Bernatowicz
,
I.
Czerski
,
J.
Jazwinski
, and
S.
Szymański
,
J. Magn. Reson.
169
,
284
(
2004
).
17.
I.
Czerski
and
S.
Szymański
,
Pol. J. Chem.
80
,
1233
(
2006
).
18.
P.
Bernatowicz
,
T.
Ratajczyk
,
A.
Shkurenko
,
B.
Kamieński
, and
S.
Szymański
,
J. Phys. Chem. C
119
,
3725
(
2015
).
19.
R.
Destro
,
T.
Pilati
, and
M.
Simonetta
,
Acta Crystallogr., Sect. B: Struct. Crystallogr. Cryst. Chem.
36
,
2495
(
1980
).
20.
A.
Hewson
,
J. Phys. C: Solid State Phys.
15
,
3841
(
1982
);
A.
Hewson
,
J. Phys. C: Solid State Phys.
15
,
3855
(
1982
).
21.
A.
Würger
,
Z. Phys. B: Condens. Matter
76
,
65
(
1989
).
22.
A.
Würger
,
J. Phys. B: Condens. Matter
1
,
6901
(
1989
).
23.
T.
Ratajczyk
and
S.
Szymański
,
J. Chem. Phys.
123
,
204509
(
2005
);
[PubMed]
T.
Ratajczyk
and
S.
Szymański
,
J. Chem. Phys.
Erratum
137
,
029902
(
2012
).
24.
T.
Ratajczyk
and
S.
Szymański
,
J. Chem. Phys.
127
,
184504
(
2007
).
25.
P.
Bernatowicz
,
A.
Shkurenko
,
A.
Osior
,
B.
Kamieński
, and
S.
Szymański
,
Phys. Chem. Chem. Phys.
17
,
28866
(
2015
).
26.
S.
Nakajima
,
Prog. Theor. Phys.
20
,
948
(
1958
).
27.
R.
Zwanzig
,
J. Chem. Phys.
33
,
1338
(
1960
);
28.
S.
Szymański
,
J. Chem. Phys.
104
,
8216
(
1996
);
S.
Szymański
,
J. Chem. Phys.
Erratum
106
,
3430
(
1997
).
29.
P.
Bernatowicz
,
T.
Ratajczyk
,
P.
Kalicki
, and
S.
Szymański
,
Solid State Nucl. Magn. Reson.
59-60
,
34
(
2014
).
30.
T.
Iwaniec
,
R.
Kopiecki
, and
S.
Szymański
,
Solid State Nucl. Magn. Reson.
68-69
,
25
(
2015
).
31.
M. J.
Frisch
,
G. W.
Trucks
,
H. B.
Schlegel
,
G. E.
Scuseria
,
M. A.
Robb
,
J. R.
Cheeseman
,
G.
Scalmani
,
V.
Barone
,
B.
Mennucci
,
G. A.
Petersson
,
H.
Nakatsuji
,
M.
Caricato
,
X.
Li
,
H. P.
Hratchian
,
A. F.
Izmaylov
,
J.
Bloino
,
G.
Zheng
,
J. L.
Sonnenberg
,
M.
Hada
,
M.
Ehara
,
K.
Toyota
,
R.
Fukuda
,
J.
Hasegawa
,
M.
Ishida
,
T.
Nakajima
,
Y.
Honda
,
O.
Kitao
,
H.
Nakai
,
T.
Vreven
,
J. A.
Montgomery
, Jr.
,
J. E.
Peralta
,
F.
Ogliaro
,
M.
Bearpark
,
J. J.
Heyd
,
E.
Brothers
,
K. N.
Kudin
,
V. N.
Staroverov
,
R.
Kobayashi
,
J.
Normand
,
K.
Raghavachari
,
A.
Rendell
,
J. C.
Burant
,
S. S.
Iyengar
,
J.
Tomasi
,
M.
Cossi
,
N.
Rega
,
J. M.
Millam
,
M.
Klene
,
J. E.
Knox
,
J. B.
Cross
,
V.
Bakken
,
C.
Adamo
,
J.
Jaramillo
,
R.
Gomperts
,
R. E.
Stratmann
,
O.
Yazyev
,
A. J.
Austin
,
R.
Cammi
,
C.
Pomelli
,
J. W.
Ochterski
,
R. L.
Martin
,
K.
Morokuma
,
V. G.
Zakrzewski
,
G. A.
Voth
,
P.
Salvador
,
J. J.
Dannenberg
,
S.
Dapprich
,
A. D.
Daniels
,
O.
Farkas
,
J. B.
Foresman
,
J. V.
Ortiz
,
J.
Cioslowski
, and
D. J.
Fox
, gaussian 09, Revision A.1,
Gaussian, Inc.
,
CT Wallingford
,
2009
.
32.
U.
Haeberlen
,
Advances in Magnetic Resonance
, Suppl. 1 (
Academic Press
,
New York
,
1976
).
33.
N.
Pislewski
,
J.
Tritt-Goc
,
M.
Bielejewski
,
A.
Rachocki
,
T.
Ratajczyk
, and
S.
Szymański
,
Solid State Nucl. Magn. Reson.
35
,
194
(
2009
).
34.
S.
Szymański
,
J. Chem. Phys.
137
,
034513
(
2012
).

Supplementary Material

You do not currently have access to this content.