M. Kubicki, P. Wagner / Journal of Molecular Structure 876 (2008) 134–139
135
Table 1
Crystal data, data collection and structure refinement
Compound
Formula
1
2
C10H10N4O2
C10H9N3O3
219.20
monoclinic
P21/n
Formula weight
Crystal system
Space group
218.22
monoclinic
P21/c
˚
a (A)
11.0134(8)
10.0994(8)
18.6433(16)
97.100(7)
2057.6(3)
8
1.41
912
0.103
10.5904(8)
17.9987(14)
10.9605(9)
100.563(6)
2053.8(3)
8
1.42
912
0.108
˚
b (A)
Scheme 1.
˚
c (A)
b (ꢁ)
3
˚
V (A )
interactions are in principle possible, and by an appropri-
ate choice of substituents one can focus on certain interac-
tions. We have previously found interesting cases of Z0 = 2
connected either with the differences in conformation or in
intermolecular interactions [8].
Here, we report the crystal structures of two simple
imidazole derivatives (Scheme 1): 1-(20-aminophenyl)-2-
methyl-4-nitroimidazole (1) and 1-(20-hydroxyphenyl)-2-
methyl-4-nitroimidazole (2). These compounds belong to
a class of compounds having higher probability of crystal-
lizing with Z0 > 1, and in fact this is a case. CSD checks do
not suggest any possibility for a missing symmetry between
the independent molecules.
Z
Dx (g cmꢀ3
F(000)
l (mmꢀ1
)
)
Crystal size (mm)
H Range (ꢁ)
hkl range
0.2 · 0.2 · 0.05
4.85–26.4
ꢀ11 6 h 6 13
ꢀ12 6 k 6 11
ꢀ22 6 l2 6 3
0.15 · 0.1 · 0.1
3–25
ꢀ12 6 h 6 11
ꢀ21 6 k 6 19
ꢀ13 6 l 6 13
Reflections
Measured
11984
4156 (0.038)
2641
11002
3603 (0.042)
2398
Unique (Rint) 4414
With I > 2r(I)
Number of parameters
Weighting scheme
A
365
357
0.07
0.049
0.132
1.05
0.05
0.040
0.098
0.98
R(F) [F2 > 2r(F2)]
wR(F2) [all refl.]
Goodness of fit
2. Experimental
The title compounds were synthesized by the ANRORC
(Addition Nucleophile Ring Opening Ring Closure) reac-
tion from 1,4-dinitro-2-methylimidazole and correspond-
ing ortho-substituted aniline in methanolꢀwater medium
at room temperature with moderate yields. The syntheses
ꢀ3
˚
Max/min Dq (e A
)
0.24/ꢀ0.24
0.24/ꢀ0.35
bridge Crystallographic Data Centre, Nos. CCDC-648297
(1) and CCDC-648298 (2). Copies of this information
may be obtained free of charge from: The Director, CCDC,
12 Union Road, Cambridge, CB2 1EZ, UK. Fax:
+44(1223)336-033, e-mail: deposit@ccdc.cam.ac.uk, or
´
were made in similar way described before by Suwinski
´
and Salwinska [11] (Scheme 1).
Diffraction data were collected at 100(1)K by the x-scan
technique up to 2h = 60ꢁ, on a KUMA-KM4CCD diffrac-
tometer [12] with graphite-monochromatized MoKa radia-
˚
tion (k = 0.71073 A). The temperature was controlled by
3. Discussion
an Oxford Instruments Cryosystems cooling device.
Frames (532) were measured for 1 and 2 (0.75ꢁ frame
width). The data were corrected for Lorentz-polarization
effects [13]. Accurate unit-cell parameters were determined
by a least-squares fit of 2613 (1) and 2851 (2) reflections of
highest intensity, chosen from the whole experiment. The
structures were solved with SHELXS97 [14] and refined
with the full-matrix least-squares procedure on F2 by
SHELXL97 [14]. Scattering factors incorporated in SHEL-
XL97 were used. The function Rw(|Fo|2-|Fc|2)2 was mini-
3.1. Molecular geometry
Selected geometrical parameters are listed in Table 2. As
far as the bond lengths and bond angles patterns are con-
cerned, the differences between the symmetry-independent
molecules are only of statistical nature. The normal proba-
bility plots [15,16] drawn for the bond length distribution
in both cases are almost linear, the correlation coefficients
between theoretical and experimental distributions are of
ca. 0.97. Also the differences between 1 and 2 are small,
with the notable exception of intraannular bond angles in
the phenyl ring. These angles show the typical dependence
on the kind of substituent (cf. Table 2); these differences are
generally in agreement with the trends described by
Domenicano and Murray-Rust [17].
2
mized, with wꢀ1 = [r2(Fo)2 + AÆP2] (P = [Max (Fo , 0) +
2
2Fc ]/3). The final values of the factor A are listed in Table
1. All non-hydrogen atoms were refined anisotropically,
hydrogen atoms were located in subsequent difference Fou-
rier maps and their positional and isotropic displacement
parameters (one common parameter for each CH3 group)
were refined. Relevant crystal data are listed in Table 1,
together with refinement details.
As noted before [18] there is a statistically significant
difference in the C–N–O angles of nitro group typical
for 5-H imidazoles: the C4–N4–O41 (oxygen atom cis
with respect to the N3 imidazole ring nitrogen) is, on
Crystallographic data (excluding structure factors) for
the structural analysis has been deposited with the Cam-