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Zeitschriftenartikel:

T. Kader, P. Kautny, B. Stöger, J. Fröhlich:
"OD- and non-OD-polytypism of 9-(3-chloropyridin-4-yl)-9H-carbazole";
Zeitschrift für Kristallographie - Crystalline Materials, 232 (2017), 5; S. 375 - 384.



Kurzfassung englisch:
9-(3-Chloropyridin-4-yl)-9
H
-carbazole (
1
) crystal
-
lizes as polytypes made up of layers of one kind with
P
(
c
)2
1
b
symmetry, in which layer contacts are geometrically non-
equivalent (non-OD polytypes). In both polytypes adjacent
layers are related by a glide reflection with a plane parallel
to (100). In polytype I (
Ic
2
a
), the intrinsic translation vector
of the glide reflection is
b
/2. In polytype II (
P
2
1
), the intrinsic
translation vector is
s
c
/2 with
s
=
0.771. It is a polytype with a
maximum degree of order (MDO) of a family of OD structures.
Fragments of the second MDO polytype lead to systematic
twinning by reflection at (100). For crystals of both polytypes
the absolute structure was determined [Flack parameters
− 0.03(5) and − 0.05(5)]. Despite being of the non-OD type,
the formalism of OD theory is applied to achieve a unified
description of the symmetry of both polytypes.

Schlagworte:
OD theory; polytypism; twinning.


"Offizielle" elektronische Version der Publikation (entsprechend ihrem Digital Object Identifier - DOI)
http://dx.doi.org/10.1515/zkri-2016-2040


Erstellt aus der Publikationsdatenbank der Technischen Universitšt Wien.