organic compounds
Table 1
Experimental details.
Table 2
Selected geometric parameters ( A˚ , ).
ꢁ
Crystal data
Chemical formula
N1—N2
N2—C3
C3—C4
1.373 (3)
1.328 (3)
1.424 (3)
C4—C5
C5—N1
C41—N41
1.379 (3)
1.363 (3)
1.289 (3)
C
310.78
17
H
15ClN
4
M
r
Crystal system, space group
Temperature (K)
1
Monoclinic, P2 /n
120
11.773 (2), 9.9525 (18), 13.760 (3)
114.519 (10)
1466.9 (5)
4
Mo Kꢂ
0.26
N2—N1—C11—C12
C5—C4—C41—N41
C4—C41—N41—N42
ꢃ131.2 (2)
176.9 (2)
ꢃ175.5 (2)
C41—N41—N42—C421
N41—N42—C421—C422
ꢃ176.2 (2)
ꢃ10.3 (3)
˚
a, b, c (A)
ꢁ
ꢁ
V (A )
( )
˚
3
Z
Radiation type
ꢃ1
ꢃ (mm
Crystal size (mm)
)
development of a significant degree of aromatic delocalization
within the pyrazole ring.
0.36 ꢄ 0.33 ꢄ 0.21
Data collection
Diffractometer
Apart from the pendent phenyl ring (atoms C11–C16), the
non-H atoms in the molecule of (I) do not deviate markedly
from coplanarity; the maximum deviation from the mean
plane of these atoms is exhibited by atom N42, whose devia-
Bruker–Nonius KappaCCD diffrac-
tometer
Multi-scan (SADABS; Sheldrick,
Absorption correction
2003)
Tmin, Tmax
0.901, 0.946
23842, 3355, 2305
˚
˚
No. of measured, independent and
observed [I > 2ꢄ(I)] reflections
tion is 0.127 (2) A, and the r.m.s. deviation is 0.058 A. In
addition, the dihedral angle between the planes of the pyra-
zole and terminal phenyl ring (atoms C421–C426) is only
R
int
0.087
0.650
˚
ꢃ1
)
(sin ꢅ/ꢆ)max (A
ꢁ
1
.9 (2) , whereas that between the pyrazole and C11–C16
Refinement
2
ꢁ
2
2
phenyl rings is 48.5 (2) . The coplanarity, apart from the C11–
C16 phenyl ring, is most plausibly associated with the ꢀ–ꢀ
stacking interactions between inversion-related pairs of mol-
ecules, as discussed below, while the twist of the C11–C16 ring
out of the plane of the rest of the molecule may be influenced
by the contact between atoms C151 and H12, where the
R[F > 2ꢄ(F )], wR(F ), S
No. of reflections
No. of parameters
0.053, 0.139, 1.04
3355
200
H-atom parameters constrained
H-atom treatment
˚
ꢃ3
)
Áꢇmax, Áꢇmin (e A
0.36, ꢃ0.49
Computer programs: COLLECT (Hooft, 1998), DIRAX/LSQ (Duisenberg et al., 2000),
EVALCCD (Duisenberg et al., 2003), SIR2004 (Burla et al., 2005), SHELXL97
(Sheldrick, 2008) and PLATON (Spek, 2009).
˚
observed nonbonded distance in (I) of 2.94 A is almost iden-
˚
tical to the sum of the van der Waals radii (2.95 A; Bondi,
1
964; Rowland & Taylor, 1996). The molecules of (I) thus
filtration and washed with cold hexane (yield 63%, m.p. 452–
4
+
55 K). MS (70 eV), m/z: 310 (M ), 275, 193, 132, 91, 77, 69, 51,
exhibit no internal symmetry, and hence they are conforma-
tionally chiral; however, the centrosymmetric space group
confirms that equal numbers of the two conformational
enantiomers are present in the crystal.
41. Yellow crystals suitable for single-crystal X-ray diffraction
were grown by slow evaporation, at ambient temperature and
in the presence of air, of a solution in dimethylformamide–
ethanol (3:7 v/v).
2.2. Refinement
Crystal data, data collection and structure refinement
details are summarized in Table 1. All H atoms were located in
difference maps and then treated as riding atoms. H atoms
bonded to C atoms were permitted to ride in geometrically
idealized positions, with C—H = 0.95 (aromatic and alkenic)
˚
or 0.98 A (methyl) and U (H) = kU (C), where k = 1.5 for
iso
eq
the methyl group, which was permitted to rotate but not to tilt,
and 1.2 for the phenyl and alkenic groups. The H atom bonded
to atom N42 was similarly permitted to ride, with an N—H
˚
distance of 0.88 A and U (H) = 1.2U (N).
iso eq
3
. Results and discussion
Within the pyrazole ring of compound (I), the N2—C3 and
˚
N1—C5 bond lengths differ by less than 0.04 A (Table 2),
despite the fact that these two bonds are formally double and
single bonds, respectively; both these bonds are very signifi-
cantly longer than the isolated N41 C41 double bond.
Similarly, the C3—C4 and C4—C5 distances differ by less than
˚
Figure 1
The molecular structure of compound (I), showing the atom-labelling
scheme. Displacement ellipsoids are drawn at the 30% probability level.
0.06 A, although these two bonds are formally single and
double bonds, respectively. These observations point to the
ꢂ
Acta Cryst. (2014). C70, 216–219
Trilleras et al.
C
17
H
15ClN
4
217