organic compounds
Acta Crystallographica Section C
Crystal Structure
Communications
triazole rings are involved, in particular the C4ÐH4Á Á ÁN3 and
C9ÐH9Á Á ÁN4 interactions (Table 2). Bond lengths and angles
in (I) are comparable with those reported for related struc-
tures (Wang et al., 1998; Fun et al., 1999). In contrast to these
related structures, however, in (I), intermolecular ꢀ±ꢀ
stacking interactions between the N1-pyridyl ring and its
symmetry partner at (1 x, 2 y, 1 z) are observed along
ISSN 0108-2701
4-Phenyl-3,5-bis(2-pyridyl)-4H-1,2,4-
triazole
Ê
the a axis, with a perpendicular distance of 3.670 (3) A. This
arrangement is further stabilized by weak intermolecular
C17ÐH17Á Á ÁN4 and C11ÐH11Á Á ÁN3 hydrogen bonds. The
geometry of these interactions is given in Table 2.
Dun-Ru Zhu, Yan Xu,* Yong Zhang, Tian-Wei Wang and
Xiao-Zeng You
In order to investigate how far packing interactions can
in¯uence the conformation of the molecule, molecular-
mechanics calculations were carried out using the MM+ force
®eld of HYPERCHEM (Autodesk Inc., 1992). The best
calculated model for the isolated molecule so obtained differs
from that found experimentally for the molecule packed in the
crystal because in the isolated molecule, the two pyridyl rings
are practically coplanar with the central triazole ring, while in
the crystal, they are rotated by an angle of about 32ꢀ. Another
relevant difference is shown by the plane of the phenyl ring
which is practically perpendicular to the plane of the triazole
ring in the isolated molecule, while it is twisted by about 65ꢀ in
the crystal. This means that conjugation between the two
pyridyl and triazole rings is favoured in the isolated molecule,
but is in some way hindered by interactions with the
surrounding molecules in the crystal. Conjugation with the
phenyl ring is hindered in both cases.
Coordination Chemistry Institute, State Key Laboratory of Coordination Chemistry,
Nanjing University, Nanjing 210093, People's Republic of China
Correspondence e-mail: ccinu@netra.nju.edu.cn
Received 25 February 2000
Accepted 10 April 2000
In the title compound, C18H13N5, the two pyridyl rings form
dihedral angles of 32.7 (2) and 30.1 (2)ꢀ with the triazole ring.
The most favoured orientation of the pyridyl rings is that with
their N atoms on opposite sides of the triazole ring directed
towards the phenyl ring. ꢀ±ꢀ-Stacking interactions involving
pyridyl rings are observed along the a axis at a perpendicular
Ê
distance of 3.670 (3) A. This arrangement is further stabilized
by weak intermolecular CÐHÁ Á ÁN hydrogen bonds.
Comment
Substituted 1,2,4-triazoles have been actively studied as
bridging ligands coordinating through their vicinal N atoms. It
is of interest that some complexes containing 1,2,4-triazole
ligands have particular structures and speci®c magnetic
properties (Vreugdenhil et al., 1987; Albada et al., 1984; Vos et
al., 1983; Kahn & Martinez, 1998). On the other hand, some of
the 1,2,4-triazole derivatives have anti-in¯ammatory activities
(Mazzone et al., 1987) and some are antifungal agents (Massa
et al., 1992). As a continuation of our investigation of the
structures of triaryltriazole compounds (Wang et al., 1998;
Chen et al., 1998; Fun et al., 1999; Shao et al., 1999), we
describe herein the structure of the title compound, (I).
Figure 1
The structure of (I) showing 50% probability displacement ellipsoids and
the atom-numbering scheme.
The title structure (Fig. 1) consists of two pyridyl rings, one
triazole ring and one phenyl ring. The four rings do not share a
common plane; the dihedral angle between the phenyl and
central triazole rings is 65.2 (3)ꢀ, and the pyridyl rings form
dihedral angles of 32.7 (2) and 30.1 (2)ꢀ with the triazole ring.
The most favoured orientation of the pyridyl rings is that with
their N atoms on opposite sides of the triazole-ring plane and
oriented towards the phenyl ring. This orientation is due to the
weak hydrogen-bond interactions in which the pyridyl and
Experimental
The title compound was prepared by the reaction of equivalent
amounts of 4,40-phenylphosphazoanilide and N,N0-dipyridoylhydra-
zine in N,N0-dimethylaniline for 3 h at 463±473 K (Grimmel et al.,
1946; Klingsberg, 1958). Diffraction-quality crystals were obtained by
recrystallization from acetone.
ꢁ
Acta Cryst. (2000). C56, 895±896
# 2000 International Union of Crystallography
Printed in Great Britain ± all rights reserved 895
Zhu, Dun-Ru
