Crystal and molecular structure of N,N,N′,N′-tetra(2- nitrilethyl) ethane-1,2-diamine and N-(2-nitrilethyl)benzylamine hydrobromide

Article abstract of DOI:10.1007/s10947-006-0312-x

N,N,N′,N′-tetra(2-nitrilethyl) ethane-1,2-diamine and N-(2-nitrilethyl)benzylamine hydrobromide were prepared by the addition reaction of acrylonitrile with corresponding amines, and the two structures were determined by X-ray single crystal diffraction. The two compounds crystallize in monoclinic system, and almost no classical hydrogen bond exists in the two crystal structures.

Full text of DOI:10.1007/s10947-006-0312-x

Journal of Structural Chemistry. Vol. 47, No. 2, pp. 383-386, 2006
Original Russian Text Copyright © 2006 by J. Gao, X.-Y. Xu, T.-T. Xu, J. Ni, and Q.-L. Liu
CRYSTAL AND MOLECULAR STRUCTURE OF
N,N,Nc,Nc-TETRA(2-NITRILETHYL) ETHANE-1,2-DIAMINE
AND N-(2-NITRILETHYL)BENZYLAMINE HYDROBROMIDE
J. Gao,1,2 X.-Y. Xu,2 T.-T. Xu,2 J. Ni,3 and Q.-L. Liu1
UDC 548.737
N,N,Nc,Nc-tetra(2-nitrilethyl) ethane-1,2-diamine and N-(2-nitrilethyl)benzylamine hydrobromide were
prepared by the addition reaction of acrylonitrile with corresponding amines, and the two structures were
determined by X-ray single crystal diffraction. The two compounds crystallize in monoclinic system, and
almost no classical hydrogen bond exists in the two crystal structures.
Keywords: N,N,Nc,Nc-tetra(2-nitrilethyl) ethane-1,2-diamine, N-(2-nitrilethyl)benzylamine hydrobromide,
structure of molecular crystals.
Nitriles are of particular interest due to their extensive applications. In organic synthesis they can convert into
amides, carboxylic acids, amines and ketones [1]; in chemical industry they are important intermediates for fine chemicals
such as medicines, agricultural chemicals and dyes; in coordination chemistry they are ideal ligands for constructing
supramolecular architectures [2, 3]. As an interest to nitriles, described herein is the synthesis and crystal structure of two
new organic nitriles N,N,Nc,Nc-tetra(2-nitrilethyl) ethane-1,2-diamine (1) and N-(2-nitrilethyl)benzylamine hydrobromide (2).
Experimental. Synthesis of N,N,Nc,Nc-tetra(2-nitrilethyl)ethane-1,2-diamine (1). To ethane-1,2-diamine aqueous
solution was added an excess solution of acrylonitrile dropwise. The solution was refluxed for 45 hr. Then excess
acrylonitrile and water were distilled out under vacuum. The colorless crystals were obtained. Yield 93%. M. p.: 60qC. IR
(cm–1, KBr): 2865, 2838 (m, Qas, Qs (CH )), 2243 (s, Q(CN)). 1H NMR (CD3OD, į) 2.64 ~ 2.68 (t, 8H, –CH2CH2CN), 2.76 (s, 4H,
2
–NCH2CH2N–), 2.92 ~ 2.96 (t, 8H, –CH2CH2CN).
Synthesis of N-(2-nitrilethyl)benzylamine hydrobromide (2). N-(2-nitrilethyl)benzylamine was prepared by
addition reaction of benzylamine with acrylonitrile. To benzylamine aqueous solution was added an excess solution of
acrylonitrile dropwise. The solution was refluxed for 75 hr. Then excess acrylonitrile and water were distilled out under
vacuum. The colorless oil product was obtained. Yield 72%. B. p.: 178-179qC (0.098 MPa). IR (cm–1, KBr): 3338 (m, Q(NH)),
2926, 2845 (m, Qas, Qs (CH )), 2247 (s, Q(CN)), 1495–1454 (benzene ring). 1H NMR (CDCl3, į) 7.24 ~ 7.30 (t, 5H, Ar—H), 3.78
2
(s, 2H, Ar–CH2–), 2.83-2.88 (t, 2H, –CH2CH2CN), 2.42-2.46 (t, 2H, –CH2CH2CN), 1.69 (s, H, –NH–). N-(2-
nitrilethyl)benzylamine hydrobromide (2) was obtained by the addition of 48% HBr to the methanol solution of N-(2-
nitrilethyl)benzylamine gradually. Slow evaporation of the above mixed solution produced colorless blocks in a yield of 95%.
1Department of Chemistry, University of Science and Technology of China, P.R. China; gaojian553@163.com.
3
2Departmemt of Chemical Engineering, Lianyungang Technical College, P.R. China. Central Laboratory of Shantou
University, P.R. China. Translated from Zhurnal Strukturnoi Khimii, Vol. 47, No. 2, pp. 388-391, March-April, 2006.
Original article submitted September 9, 2005.
0022-4766/06/4702-0383 © 2006 Springer Science+Business Media, Inc.
383

1
IR (cm–1, KBr): 3165 (m, Q(NH)), 2915, 2833 (m, Qas, Qs (CH )), 2756 (s, Q(HBr)), 2243 (m, Q(CN)), 1491-1441 (benzene ring). H
2
NMR (DMSO, į) 7.44-7.53 (t, 5H, Ar–H), 4.21 (s, 2H, Ar–CH2–), 3.36-3.38 (t, 2H, –CH2CH2CN), 3.28-3.33 (t, 2H,
–CH2CH2CN), 2.99-3.04 (t, 2H, –NH2–).
X-ray diffraction study. The intensity data were collected on a SMART APEX CCD diffractometer at room
temperature (Z-2T scan mode, graphite monochromated MoKD radiation, O = 0.71073 Å). The unit cell parameters and details of
experiment are given in Table 1. The structures were solved by direct methods and refined anisotropically using the least-squares
technique implemented in the SHELX-97 package [4, 5]. All hydrogen atoms were added according to theoretical models.
Results and discussion. The atomic coordinates and thermal parameters of atoms for 1 and 2 are given in Table 2;
the bond lengths and angles are presented in Table 3. The molecular and crystal structures of compounds 1 and 2 are shown
in Fig. 1, and Fig. 2, respectively.
TABLE 1. Crystal Data and Details of Experiment for 1 and 2
Compound
Formula
1
2
C14H20N6
C10H13N2Br
Molecular weight
Crystal size, mm
Space group, Z
a, b, c, Å
272.36
241.13
0.30×0.30×0.28
0.3×0.2×0.14
P2(1)/n, 2
P2(1)/c, 4
5.4702(7), 11.2192(14), 13.0369(16)
6.4596(9), 15.072(2), 12.2635(18)
92.670(2)
799.22(17)
1.132
101.807(2)
1168.7(3)
1.370
E, deg
V, Å3
U
calc , g/cm3
P, mm–1
0.073
3.478
No. of reflections
Independent reflections
No. of refined parameters
No. of reflections with I > 2V(I )
R1, wR2 for I > 2V(I )
wR2 for all Independent reflections
GOOF
4651
6711
1791
2401
91
118
1402
1691
0.0537, 0.1349
0.1443
0.988
0.0309, 0.0669
0.0764
0.993
CCDC
282984
257996
TABLE 2. Atomic Coordinates (×104) and Thermal Parameters (Å2×103) for 1 and 2
Atom
x
y
z
Ueq
Atom
x
y
z
Ueq
1
2
C(1)
C(2)
C(3)
C(4)
C(5)
–154(3)
2220(3)
2885(3)
811(3)
6559(2)
6860(1)
8161(1)
10082(1)
9157(1)
270(2)
753(1)
582(1)
483(1)
2139(1)
68(1)
60(1)
51(1)
48(1)
53(1)
C(6)
C(7)
N(1)
N(2)
N(3)
–591(3)
–1810(3)
–1986(3)
1147(2)
9228(1)
8083(2)
6321(2)
8958(1)
7178(2)
2745(1)
2756(1)
–111(2)
1047(1)
2764(1)
58(1)
60(1)
103(1)
44(1)
90(1)
1716(3)
–2719(3)
Br(1)
N(1)
N(2)
C(1)
C(2)
C(3)
C(4)
2711(1)
7916(3)
5514(7)
7420(5)
8150(7)
10215(8)
11538(6)
4096(1)
3754(1)
3926(2)
3729(2)
4023(2)
3886(2)
3446(3)
9637(1)
–205(1)
–4172(2)
2326(2)
3405(3)
3917(3)
3374(3)
58(1)
38(1)
119(1)
66(1)
85(1)
88(1)
85(1)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
10821(5)
8763(4)
7977(5)
7206(4)
7063(5)
6194(6)
3155(2)
3296(2)
2993(2)
3497(2)
4318(2)
4100(2)
2294(2)
1762(2)
580(2)
–1393(2)
–2116(2)
–3279(3)
66(1)
49(1)
54(1)
46(1)
63(1)
76(1)
384

TABLE 3. Bond Lengths (Å) and Angles Z (deg) for 1 and 2
1
Bond
d
Bond
d
Bond
d
C(1)–N(1)
C(1)–C(2)
C(2)–C(3)
1.130(2)
1.456(2)
1.523(2)
C(4)–N(2)
C(4)–C(4)#1
C(5)–N(2)
1.4677(16)
1.517(3)
C(5)–C(6)
C(6)–C(7)
C(7)–N(3)
1.522(2)
1.448(2)
1.130(2)
1.4597(17)
Angle
Angle
Angle
Z
Z
Z
N(1)–C(1)–C(2)
C(1)–C(2)–C(3)
N(2)–C(3)–C(2)
N(2)–C(4)–C(4)#1
179.4(2)
111.91(13)
111.22(12)
111.48(13)
N(2)–C(5)–C(6)
C(7)–C(6)–C(5)
N(3)–C(7)–C(6)
111.68(11)
110.64(13)
178.66(19)
C(5)–N(2)–C(3)
C(5)–N(2)–C(4)
C(3)–N(2)–C(4)
112.70(10)
111.98(10)
112.76(11)
2
Bond
d
Bond
d
Bond
d
N(1)–C(8)
N(1)–C(7)
N(2)–C(10)
C(6)–C(7)
1.486(3)
1.492(3)
1.124(4)
1.505(3)
C(1)–C(6)
C(1)–C(2)
C(2)–C(3)
C(8)–C(9)
1.379(4)
1.384(4)
1.369(6)
1.515(4)
C(3)–C(4)
C(4)–C(5)
C(5)–C(6)
C(9)–C(10)
1.359(5)
1.382(4)
1.372(4)
1.459(4)
Angle
Angle
Angle
Z
Z
Z
C(8)–N(1)–C(7)
C(6)–C(1)–C(2)
C(3)–C(2)–C(1)
C(4)–C(3)–C(2)
C(3)–C(4)–C(5)
113.17(19)
120.3(3)
120.0(4)
120.1(3)
120.2(3)
C(6)–C(5)–C(4)
C(5)–C(6)–C(1)
C(5)–C(6)–C(7)
C(1)–C(6)–C(7)
120.6(3)
118.8(3)
121.0(3)
120.2(3)
N(1)–C(7)–C(6)
N(1)–C(8)–C(9)
C(10)–C(9)–C(8)
N(2)–C(10)–C(9)
110.3(2)
109.3(2)
110.7(2)
179.4(5)
Fig. 1. Molecular structure and crystal packing for compound 1.
The structure of molecule 1 has much in common with the structure of bi(2-nitrilethyl)aminoacetonitrile in our
previous report [6]. The bond distances of C(1)–N(1) and C(7)–N(3) are all 1.130 Å, belonging to the typical CŁN. The bond
length of C(6)–C(7) is smaller than that of C(6)–C(5), which can be attributed to the effect of hyperconjugation, so do the
other arms. Fig. 1b shows that the layer-like structure is formed when every molecule is linked to others by intermolecular
van der Waals forces.
In Fig. 2a, the phenyl ring together with the adjacent C(7) atom defines a plane: 2.186x + 13.174y – 5.032z = 5.3713,
385

Fig. 2. Molecular structure and crystal packing for compound 2.
TABLE 4. Hydrogen Bond Geometries (Å, deg)
dD–H
dH…A
dD…A
…
A
[ARU]
TDHA
D–H
…
[1654.01]
[1554.01]
[3666.01]
0.9810
0.9347
0.9347
2.2406
2.7522
2.6035
3.184(2)
3.368(2)
3.356(2)
161.04
124.24
137.86
N(1)–H(1A) Br(1)
…
N(1)–H(1B) Br(1)
…
N(1)–H(1B) Br(1)
with the maximum deviation of 0.0291 Å for H(3), and mean deviation of 0.0106 Å. The distance between Br(1) and the
centroid of aromatic ring is 10.198 Å, which is too long to have interaction. Fig. 2b shows its layer-like crystal structure,
which is formed by intermolecular van der Waals forces and intermolecular hydrogen bonds between Br(1) and N(1) atoms.
The bond lengths and bond angles of the hydrogen bonds are listed in Table 4.
From the spectra characterization and crystal structure of 2, it can be found that monocyanoethylation of
benzylamine has occurred, and dicyanoethylation is very difficult without the aid of catalyst. But ethane-1,2-diamine, being
primary aliphatic amine, can react completely with acrylonitrile in the absence of catalysts with high yields, and aniline did
not react with acrylonitrile in a sealed tube at 200qC in the absence of a catalyst nor did any reaction take place between the
two when refluxed [7]. The difference among them could mainly be attributed to the higher steric hindrance of benzylamine
compared with ethane-1,2-diamine, and lower steric hindrance compared with aniline.
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