Acta Cryst.(2004). E60, o409±o410 DOI: 10.1107/S1600536804003393 Huang, Zhang and Sung C11H12N2O2
o409
organic papers
Acta Crystallographica Section E Structure Reports
Online
ISSN 1600-5368
6-Nitro-2-propyl-1
H
-indole
Xianghong Huang,aQian-Feng Zhangb* and Herman H. Y. Sungc
aCollege of Applied Technology, Wenzhou
University, Wenzhou, Zhejiang 325035, People's Republic of China,bDepartment of
Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan, Anhui 243002, People's Republic of China, and
cDepartment of Chemistry, Hong Kong
University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, People's Republic of China
Correspondence e-mail: [email protected]
Key indicators Single-crystal X-ray study
T= 100 K
Mean(C±C) = 0.003 AÊ
Rfactor = 0.052
wRfactor = 0.142
Data-to-parameter ratio = 14.7
For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.
#2004 International Union of Crystallography Printed in Great Britain ± all rights reserved
There are two independent molecules in the asymmetric unit of the title compound, C11H12N2O2, which differ in the
conformation of the propyl substituent. NÐH O, CÐH O
and ± interactions between inversion-related molecules
result in a supramolecular assembly.
Comment
Indole compounds can be used as bioactive drugs (Stevenson
et al., 2000). Effective hydrogen-bonding interactions are observed in these compounds (Sonaret al., 2004). Recently, we have carried out a large scale synthesis of a series of indole compounds. We report here the structure of the title compound, 6-nitro-2-propyl-1H-indole, (I).
The asymmetric unit of (I) (Fig. 1) consists of pair of
mol-ecules (A and B) held together by CÐH interactions
(Table 2). In one molecule of the enantiomeric pair, the plane through the indole ring system forms a dihedral angle of
55.9 (2) with the C2/C10ÐC12 plane [61.4 (3) in the other
molecule]. No signi®cant differences are found between the corresponding bond distances and angles in these two mol-ecules (see Table 1); the bond lengths in (I) are within normal ranges (Allenet al., 1987). All the CÐC bond distances in the
indole ring system have typical Csp2ÐCsp2 values. The
average CÐC bond distances within the rings of the two independent indole moieties are 1.400 (3) and 1.398 (3) AÊ. In the ®ve-membered rings, the intra-ring bond angles range
from 106.3 (2) to 109.6 (2); the N1ÐC2 and N1ÐC9 bond
lengths [average 1.375 (3) AÊ] are well within the range of the
Received 4 February 2004 Accepted 12 February 2004 Online 20 February 2004
Figure 1
values normally considered standard for CÐN (1.47 AÊ) and C N (1.28 AÊ) bonds, which indicates that the geometry
around N1 is normal sp2 coordination, as expected for
-conjugation of the indole ring (Sonar et al., 2004; Du & Zhao, 2003). The sums of the angles around atoms N2 show planar con®gurations, with an average N O bond length of
1.237 (2) AÊ. In both molecules, the NO2 fragment is almost
coplanar with the indole ring system.
In the crystal structure, inversion-related molecules are
linked by NÐH O and weak CÐH O interactions (Table
2), forming a supramolecular layered architecture (Fig. 2). The crystal packing is further stabilized by±stacking interac-tions between the indole ring systems of moleculeAat (x,y, z) and (1ÿx, 1ÿy, 1ÿz), with their centroids separated by 3.568 (2) AÊ.
Experimental
The title compound was synthesized by a modi®cation of the method previously described for the Sonogashira coupling reaction (Rodri-guezet al., 2000) of 2-amino-3-nitrophenol and 1-n-pentaacetylene under the catalysis of Pd(PPh3)4, CuI andn-Bu4NI in DMF. Light
yellow crystals of (I) were obtained by slow evaporation of an ethanol solution at 277 K.
Crystal data
C11H12N2O2
Mr= 204.23 Triclinic,P1
a= 8.229 (2) AÊ
b= 11.828 (3) AÊ
c= 12.088 (3) AÊ = 67.403 (4) = 86.940 (4) = 74.256 (4) V= 1043.8 (5) AÊ3
Z= 4
Dx= 1.300 Mg mÿ3 MoKradiation Cell parameters from 1705
re¯ections = 2.8±27.4 = 0.09 mmÿ1
T= 100 (2) K Block, light yellow 0.400.250.20 mm
Data collection
Bruker SMART CCD area-detector diffractometer
'and!scans
Absorption correction: multi-scan (SADABS; Sheldrick, 1997)
Tmin= 0.68,Tmax= 1.00
7051 measured re¯ections
3980 independent re¯ections 2616 re¯ections withI> 2(I)
Rint= 0.038
max= 26.0
h=ÿ8!10
k=ÿ14!14
l=ÿ14!14
Re®nement
Re®nement onF2
R[F2> 2(F2)] = 0.052
wR(F2) = 0.142
S= 0.95 3980 re¯ections
H-atom parameters constrained
w= 1/[2(F
o2) + (0.0899P)2] whereP= (Fo2+ 2Fc2)/3 (/)max< 0.001
= 0.38 e AÊÿ3
Table 1
Selected geometric parameters (AÊ,).
O1AÐN2A 1.235 (2)
O2AÐN2A 1.244 (3)
N1AÐC9A 1.374 (3)
N1AÐC2A 1.377 (3)
N2AÐC7A 1.457 (3)
O1BÐN2B 1.233 (2)
O2BÐN2B 1.236 (2)
N1BÐC2B 1.374 (3)
N1BÐC9B 1.376 (3)
N2BÐC7B 1.446 (3)
C9AÐN1AÐC2A 109.5 (2) O1AÐN2AÐO2A 122.39 (19) O1AÐN2AÐC7A 119.6 (2) O2AÐN2AÐC7A 118.0 (2) N1AÐC2AÐC3A 108.7 (2) N1AÐC2AÐC10A 122.0 (2) C8AÐC7AÐN2A 117.9 (2) C6AÐC7AÐN2A 117.7 (2) N1AÐC9AÐC8A 129.8 (2) N1AÐC9AÐC4A 107.78 (19)
C2BÐN1BÐC9B 109.59 (19) O1BÐN2BÐO2B 121.9 (2) O1BÐN2BÐC7B 119.4 (2) O2BÐN2BÐC7B 118.66 (19) C3BÐC2BÐN1B 109.0 (2) N1BÐC2BÐC10B 121.9 (2) C8BÐC7BÐN2B 118.2 (2) C6BÐC7BÐN2B 118.7 (2) N1BÐC9BÐC8B 130.1 (2) N1BÐC9BÐC4B 107.1 (2)
Table 2
Hydrogen-bonding geometry (AÊ,).
Cg1 andCg2 denote the centroids of the ®ve-membered rings in moleculesA
andB, respectively.
DÐH A DÐH H A D A DÐH A
N1AÐH1AA O2Bi 0.88 2.10 2.965 (3) 167
N1BÐH1BA O2Aii 0.88 2.07 2.948 (3) 173
C8AÐH8AA O2Aii 0.95 2.53 3.203 (3) 128
C11AÐH11B O2Bi 0.99 2.54 3.448 (3) 153
C10BÐH10D Cg1 0.99 2.78 3.726 (3) 161
C11AÐH11A Cg2 0.99 2.72 3.346 (3) 121
Symmetry codes: (i) 2ÿx;1ÿy;2ÿz; (ii) 2ÿx;1ÿy;1ÿz.
H atoms were placed in calculated positions (CÐH = 0.95±0.99 AÊ and NÐH = 0.88 AÊ) and were allowed to ride on their parent atoms. TheUiso(H) values were set to 1.5Ueq(parent) for the methyl H atoms
and 1.2Ueq(C) for other H atoms.
Data collection:SMART(Bruker, 1998); cell re®nement:SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXTL (Bruker, 1997); program(s) used to re®ne structure:SHELXTL; molecular graphics:SHELXTL; software used to prepare material for publication:SHELXTL.
This work is supported by the Key Scienti®c Research Foundation of the State Education Ministry (grant No. 90301005) and Natural Science Foundation of China (grant No. 204067).
References
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987).J. Chem. Soc. Perkin Trans.2, pp. S1±19.
Bruker (1997). SHELXTL. Version 5.1. Bruker AXS Inc., Madison, Wisconsin, USA.
Bruker (1998). SMART and SAINT. Versions 6.02a. Bruker AXS Inc., Madison, Wisconsin, USA.
Du, M. & Zhao, X. J. (2003).Acta Cryst.E59, o1645±o1647.
Rodriguez, A. L., Koradin, C., Dohle, W. & Knochel, P. (2000).Angew. Chem. Int. Ed.39, 2488±2490.
Sheldrick, G. M. (1997).SADABS. University of GoÈttingen, Germany. Sonar, V. N., Parkin, S. & Crooks, P. A. (2004).Acta Cryst.C60, o6±o8. Stevenson, G. I., Smith, A. L., Lewis, S., Michie, S. G., Neduvelil, J. G., Patel, S.,
Marwood, R., Patel, S. & Castro, J. L. (2000).Bioorg. Med. Chem. Lett.10, Figure 2
supporting information
sup-1 Acta Cryst. (2004). E60, o409–o410
supporting information
Acta Cryst. (2004). E60, o409–o410 [https://doi.org/10.1107/S1600536804003393]
6-Nitro-2-propyl-1
H
-indole
Xianghong Huang, Qian-Feng Zhang and Herman H. Y. Sung
6-Nitro-2-propyl-1H-indole
Crystal data
C11H12N2O2 Mr = 204.23
Triclinic, P1 Hall symbol: -P 1 a = 8.229 (2) Å b = 11.828 (3) Å c = 12.088 (3) Å α = 67.403 (4)° β = 86.940 (4)° γ = 74.256 (4)° V = 1043.8 (5) Å3
Z = 4 F(000) = 432 Dx = 1.300 Mg m−3
Mo Kα radiation, λ = 0.71073 Å Cell parameters from 1705 reflections θ = 2.8–27.4°
µ = 0.09 mm−1 T = 100 K
Block, light yellow 0.40 × 0.25 × 0.20 mm
Data collection
Bruker CCD area-detector diffractometer
Radiation source: fine-focus sealed tube Graphite monochromator
φ and ω scans
Absorption correction: multi-scan (SADABS; Sheldrick, 1997) Tmin = 0.68, Tmax = 1.00
7051 measured reflections 3980 independent reflections 2616 reflections with I > 2σ(I) Rint = 0.038
θmax = 26.0°, θmin = 1.8° h = −8→10
k = −14→14 l = −14→14
Refinement
Refinement on F2 Least-squares matrix: full R[F2 > 2σ(F2)] = 0.052 wR(F2) = 0.142 S = 0.95 3980 reflections 271 parameters 0 restraints
Primary atom site location: structure-invariant direct methods
Secondary atom site location: difference Fourier map
Hydrogen site location: inferred from neighbouring sites
H-atom parameters constrained w = 1/[σ2(Fo2) + (0.0899P)2]
where P = (Fo2 + 2Fc2)/3 (Δ/σ)max < 0.001
Special details
Experimental. The data collection covered over a hemisphere of reciprocal space by a combination of three sets of exposures; each set had a different φ angle (0, 88 and 180°) for the crystal and each exposure of 20 s covered 0.3° in ω. The crystal-to-detector distance was 4 cm and the detector swing angle was -35°. Coverage of the unique set is over 99% complete. Crystal decay was monitored by repeating fifty initial frames at the end of data collection and analysing the duplicate reflections, and was found to be negligible.
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)
x y z Uiso*/Ueq
supporting information
sup-3 Acta Cryst. (2004). E60, o409–o410
N2B 1.0889 (3) 0.6451 (2) 1.11582 (17) 0.0243 (5) C2B 0.7741 (3) 0.8825 (2) 0.6231 (2) 0.0213 (5) C3B 0.7285 (3) 0.9665 (2) 0.6784 (2) 0.0239 (6) H3BA 0.6577 1.0510 0.6441 0.029* C4B 0.8061 (3) 0.9048 (2) 0.7970 (2) 0.0225 (5) C5B 0.8084 (3) 0.9404 (2) 0.8949 (2) 0.0282 (6) H5BA 0.7470 1.0232 0.8892 0.034* C6B 0.9000 (3) 0.8548 (2) 0.9991 (2) 0.0279 (6) H6BA 0.9028 0.8783 1.0656 0.033* C7B 0.9894 (3) 0.7325 (2) 1.0066 (2) 0.0222 (5) C8B 0.9894 (3) 0.6920 (2) 0.9134 (2) 0.0212 (5) H8BA 1.0485 0.6082 0.9209 0.025* C9B 0.8986 (3) 0.7802 (2) 0.80899 (19) 0.0181 (5) C10B 0.7279 (3) 0.9004 (2) 0.4985 (2) 0.0250 (6) H10C 0.6479 0.9856 0.4592 0.030* H10D 0.6689 0.8363 0.5028 0.030* C11B 0.8803 (3) 0.8883 (3) 0.4209 (2) 0.0324 (6) H11C 0.9433 0.9492 0.4196 0.039* H11D 0.9573 0.8014 0.4570 0.039* C12B 0.8263 (4) 0.9146 (3) 0.2925 (2) 0.0402 (7) H12D 0.9265 0.9062 0.2457 0.060* H12E 0.7516 1.0012 0.2560 0.060* H12F 0.7659 0.8534 0.2934 0.060*
Atomic displacement parameters (Å2)
U11 U22 U33 U12 U13 U23
C4B 0.0184 (13) 0.0256 (12) 0.0237 (12) −0.0081 (10) 0.0014 (10) −0.0081 (10) C5B 0.0281 (15) 0.0284 (13) 0.0299 (14) −0.0060 (11) 0.0013 (11) −0.0141 (11) C6B 0.0311 (15) 0.0314 (14) 0.0239 (13) −0.0090 (12) 0.0004 (11) −0.0131 (11) C7B 0.0149 (12) 0.0286 (13) 0.0205 (12) −0.0072 (10) −0.0010 (9) −0.0057 (10) C8B 0.0118 (12) 0.0255 (13) 0.0267 (13) −0.0076 (10) 0.0039 (10) −0.0093 (10) C9B 0.0106 (12) 0.0262 (12) 0.0195 (11) −0.0096 (10) 0.0033 (9) −0.0081 (10) C10B 0.0181 (13) 0.0323 (14) 0.0247 (13) −0.0107 (11) 0.0014 (10) −0.0086 (11) C11B 0.0191 (14) 0.0540 (18) 0.0288 (14) −0.0114 (13) 0.0029 (11) −0.0204 (13) C12B 0.0390 (18) 0.0568 (19) 0.0261 (14) −0.0099 (15) 0.0023 (12) −0.0196 (13)
Geometric parameters (Å, º)
O1A—N2A 1.235 (2) O1B—N2B 1.233 (2) O2A—N2A 1.244 (3) O2B—N2B 1.236 (2) N1A—C9A 1.374 (3) N1B—C2B 1.374 (3) N1A—C2A 1.377 (3) N1B—C9B 1.376 (3) N1A—H1AA 0.88 N1B—H1BA 0.88 N2A—C7A 1.457 (3) N2B—C7B 1.446 (3) C2A—C3A 1.381 (3) C2B—C3B 1.362 (3) C2A—C10A 1.491 (3) C2B—C10B 1.493 (3) C3A—C4A 1.425 (3) C3B—C4B 1.427 (3) C3A—H3AA 0.95 C3B—H3BA 0.95 C4A—C5A 1.403 (3) C4B—C5B 1.402 (3) C4A—C9A 1.421 (3) C4B—C9B 1.418 (3) C5A—C6A 1.381 (3) C5B—C6B 1.373 (4) C5A—H5AA 0.95 C5B—H5BA 0.95 C6A—C7A 1.403 (3) C6B—C7B 1.405 (3) C6A—H6AA 0.95 C6B—H6BA 0.95 C7A—C8A 1.378 (3) C7B—C8B 1.382 (3) C8A—C9A 1.389 (3) C8B—C9B 1.381 (3) C8A—H8AA 0.95 C8B—H8BA 0.95 C10A—C11A 1.523 (3) C10B—C11B 1.535 (3) C10A—H10A 0.99 C10B—H10C 0.99 C10A—H10B 0.99 C10B—H10D 0.99 C11A—C12A 1.526 (3) C11B—C12B 1.527 (4) C11A—H11A 0.99 C11B—H11C 0.99 C11A—H11B 0.99 C11B—H11D 0.99 C12A—H12A 0.98 C12B—H12D 0.98 C12A—H12B 0.98 C12B—H12E 0.98 C12A—H12C 0.98 C12B—H12F 0.98
supporting information
sup-5 Acta Cryst. (2004). E60, o409–o410
N1A—C2A—C10A 122.0 (2) C3B—C2B—C10B 129.1 (2) C3A—C2A—C10A 129.4 (2) N1B—C2B—C10B 121.9 (2) C2A—C3A—C4A 107.8 (2) C2B—C3B—C4B 107.8 (2) C2A—C3A—H3AA 126.1 C2B—C3B—H3BA 126.1 C4A—C3A—H3AA 126.1 C4B—C3B—H3BA 126.1 C5A—C4A—C9A 119.2 (2) C5B—C4B—C9B 118.7 (2) C5A—C4A—C3A 134.5 (2) C5B—C4B—C3B 134.9 (2) C9A—C4A—C3A 106.3 (2) C9B—C4B—C3B 106.5 (2) C6A—C5A—C4A 119.4 (2) C6B—C5B—C4B 119.6 (2) C6A—C5A—H5AA 120.3 C6B—C5B—H5BA 120.2 C4A—C5A—H5AA 120.3 C4B—C5B—H5BA 120.2 C5A—C6A—C7A 119.0 (2) C5B—C6B—C7B 119.6 (2) C5A—C6A—H6AA 120.5 C5B—C6B—H6BA 120.2 C7A—C6A—H6AA 120.5 C7B—C6B—H6BA 120.2 C8A—C7A—C6A 124.3 (2) C8B—C7B—C6B 123.1 (2) C8A—C7A—N2A 117.9 (2) C8B—C7B—N2B 118.2 (2) C6A—C7A—N2A 117.7 (2) C6B—C7B—N2B 118.7 (2) C7A—C8A—C9A 115.7 (2) C9B—C8B—C7B 116.3 (2) C7A—C8A—H8AA 122.1 C9B—C8B—H8BA 121.9 C9A—C8A—H8AA 122.1 C7B—C8B—H8BA 121.9 N1A—C9A—C8A 129.8 (2) N1B—C9B—C8B 130.1 (2) N1A—C9A—C4A 107.78 (19) N1B—C9B—C4B 107.1 (2) C8A—C9A—C4A 122.4 (2) C8B—C9B—C4B 122.8 (2) C2A—C10A—C11A 114.47 (19) C2B—C10B—C11B 113.6 (2) C2A—C10A—H10A 108.6 C2B—C10B—H10C 108.9 C11A—C10A—H10A 108.6 C11B—C10B—H10C 108.9 C2A—C10A—H10B 108.6 C2B—C10B—H10D 108.9 C11A—C10A—H10B 108.6 C11B—C10B—H10D 108.9 H10A—C10A—H10B 107.6 H10C—C10B—H10D 107.7 C10A—C11A—C12A 112.6 (2) C12B—C11B—C10B 111.7 (2) C10A—C11A—H11A 109.1 C12B—C11B—H11C 109.3 C12A—C11A—H11A 109.1 C10B—C11B—H11C 109.3 C10A—C11A—H11B 109.1 C12B—C11B—H11D 109.3 C12A—C11A—H11B 109.1 C10B—C11B—H11D 109.3 H11A—C11A—H11B 107.8 H11C—C11B—H11D 107.9 C11A—C12A—H12A 109.5 C11B—C12B—H12D 109.5 C11A—C12A—H12B 109.5 C11B—C12B—H12E 109.5 H12A—C12A—H12B 109.5 H12D—C12B—H12E 109.5 C11A—C12A—H12C 109.5 C11B—C12B—H12F 109.5 H12A—C12A—H12C 109.5 H12D—C12B—H12F 109.5 H12B—C12A—H12C 109.5 H12E—C12B—H12F 109.5
Hydrogen-bond geometry (Å, º)
D—H···A D—H H···A D···A D—H···A
C11A—H11B···O2Bi 0.99 2.54 3.448 (3) 153 C10B—H10D···Cg1 0.99 2.78 3.726 (3) 161 C11A—H11A···Cg2 0.99 2.72 3.346 (3) 121
