organic compounds
in the para-substituted compound, the increase is larger
ꢀ
effects have also been observed in all derivatives of N-methyl-
N-phenylnitramine (Cady, 1967; Prezhdo et al., 2001; Zhukh-
listova et al., 2002).
ꢀ
[1.7 (2) ]. In (I), however, this angle is decreased by 1.4 (1) . It
should be mentioned that the CÐCÐC angle to which the
±
group is connected are quite similar [2.2 (1) for the ortho and
para, but 2.6 (1) for the meta compound]. Taking into account
only the geometric structures of (I) and (II), it seems that the
deformation of the aromatic ring is caused more by steric
hindrance than by the ꢀ-electron interactions.
NO group is connected and that to which the ±N(Me)NO2
ꢀ
In both title structures, the crystal packing is stabilized by
weak intermolecular CÐHÁ Á ÁO hydrogen bonds (Tables 2
and 4), forming an extended three-dimensional network in
each case. The polarity of the nitramine group and the
distribution of the partial charges in¯uence the formation of
hydrogen bonds. In both studied structures, the hydrogen
bonds involve only the O atoms of the nitro group connected
2
ꢀ
In both structures, the nitro groups are not coplanar with
ꢀ
the aromatic rings; the group is twisted by 11.9 (2) for (I) and
ꢀ
to atom N7. The NO group bound to the phenyl ring does not
2
by 22.1 (2) for (II) with respect to the ring plane. A much
ꢀ
participate in the hydrogen-bonding scheme in either
compound.
smaller twist [2.5 (2) ] is observed in the para isomer
(Anulewicz et al., 1993). In the overcrowded structure of (I),
the position of the nitro group causes an increase of the C1Ð
Experimental
ꢀ
C2ÐN12 angle to 121.8 (1) and a decrease of the C3ÐC2Ð
ꢀ
For the preparation of (I), solid N-methyl-2-nitroaniline (3 g,
20 mmol) was added in portions to cold acetic anhydride (30 ml)
containing nitric acid (1.7 ml, 41 mmol, HNO , d = 1.5). The solution
N12 angle to 117.5 (1) . In (II), both related angles are smaller
ꢀ
ꢀ
than 120 [by 2.6 (1) and 0.8 (1) ].
3
In both studied molecules, the NÐNO2 group is not
coplanar with the aromatic ring, which suggests a lack of
interaction between these two groups. In (I) and 4-nitro-N-
was kept for 30 min at room temperature and evaporated in vacuo
(323 K). The residue was crystallized from methanol and recrys-
tallized from ethanol, producing N-methyl-N-(2-nitrophenyl)-
methyl-N-phenylnitramine, the N-methylnitramine group is
ꢀ
nitramine, (I), as colourless crystals (2.5 g, 63%, m.p. 340±341 K). MS
(
+
m/z) (intensity): 197 (M , 4), 151 (97), 134 (100), 121 (11), 105 (38),
twisted along the C ÐN bond by � 80.4 (1) and � 72.3 (2) ,
ar
�
1
9
3 (60), 77 (69); IR (KBr, cm ): 1530, 1523 (ꢁas NÐO), 1345, 1295 (ꢁ
s
respectively. This is a characteristic feature of N-methyl-N-(4-
nitrophenyl)nitramine derivatives. It should be noted,
however, that N-methyl-N-phenylnitramine has a smaller twist
1
NÐO); H NMR (CDCl
.74 (s, 3H, N-methyl group). N-Methyl-N-(3-nitrophenyl)nitramine,
II), was prepared according to the above procedure. The nitramine
was obtained in 72% yield as colourless crystals (m.p. 347±348 K). MS
3
): ꢂ 8.24±7.43 (m, 4H, aromatic H atoms),
3
(
ꢀ
angle [� 66.3 (2) ], whereas in (II), the group is twisted by an
ꢀ
even smaller angle [� 49.6 (1) ].
+
(
m/z) (intensity): 197 (M , 2), 151 (100), 122 (10), 105 (80), 93 (4),
� 1
The bond lengths and angles of the nitramine group agree
with the corresponding values found in N-methyl-N-(4-
nitrophenyl)nitramine. Atom N7 lies slightly out of the plane
1
7
7 (16); IR (KBr, cm ): 1528 (ꢁas NÐO), 1351, 1291 (ꢁ
s
NÐO); H
NMR (CDCl
atoms), 3.78 (s, 3H, N-methyl group).
3
): ꢂ 8.33±8.22 (m, 2H), 7.74±7.67 (m, 2H, aromatic H
Ê
of the benzene ring [the deviation is 0.026 (1) A in (I) and
Ê
.109 (1) A in (II)]. In (II), the sum of the valence angles
0
around atom N7 [360.0 (1) ] indicates trigonal hybridization
Compound (I)
ꢀ
Crystal data
ꢀ
of the amine N atom. In (I), however, this sum is 358.9 (1) and
Ê
atom N7 lies 0.086 (1) A from the C1/N8/C11 plane.
C
H
7 7
N O
3 4
Mo Kꢄ radiation
M
r
= 197.16
Cell parameters from 5344
re¯ections
Ê
The N7ÐN8 bond lengths [1.349 (2) A for (I) and
Monoclinic, P2 =n
1
a = 7.0470 (8) AÊ
b = 14.4473 (12) A
ꢀ
Ê
.355 (1) A for (II)] have values intermediate between those
ꢅ = 3.2±26.0
1
of typical single (1.45 A) and double (1.25 A) bonds, as
expected (Allen et al., 1995; Daszkiewicz et al., 2002). Similar
Ê
� 1
ꢆ = 0.13 mm
T = 100.0 (1) K
Ê
Ê
Ê
c = 8.1165 (8) A
ꢀ
ꢃ = 90.814 (8)
Irregular, colourless
0.2 Â 0.2 Â 0.15 mm
Ê
3
V = 826.26 (14) A
Z = 4
�
3
D
x
= 1.585 Mg m
Data collection
Oxford Diffraction Xcalibur
diffractometer
Rint = 0.030
ꢀ
ꢅ
max = 26.0
!
scan
h = � 8 ! 8
5
1
1
344 measured re¯ections
591 independent re¯ections
294 re¯ections with I > 2ꢇ(I)
k = � 17 ! 11
l = � 10 ! 10
Re®nement
2
Re®nement on F
2
(Á/ꢇ)max < 0.001
2
Ê
� 3
Áꢈmax = 0.24 e A
R[F > 2ꢇ(F )] = 0.032
wR(F ) = 0.089
S = 1.05
2
Ê
� 3
Áꢈmin = � 0.23 e A
Extinction correction: SHELXL97
Extinction coef®cient: 0.024 (4)
1
1
591 re¯ections
56 parameters
Figure 2
The molecular structure of (II), showing the atom labelling. Displacement
ellipsoids are drawn at the 50% probability level.
All H-atom parameters re®ned
2 2
2
w = 1/[ꢇ (F ) + (0.0566P) ]
o
2
2
where P = (Fo + 2F )/3
c
ꢁ
o516 Zarychta et al.
7 7
C H N
O
3 4
7 7
and C H N
O
3 4
Acta Cryst. (2005). C61, o515±o517
Zarychta, Bartosz
