5-(Trifluoro­meth­oxy)isatin

Schutte, M.; Pretorius, C.; Visser, H.G.; Roodt, A.

doi:10.1107/S1600536812044297

Volume 68
Part 12
Page o3472
December 2012

Received 17 September 2012
Accepted 25 October 2012
Online 28 November 2012

Key indicators
Single-crystal X-ray study
T = 100 K
Mean (C-C) = 0.002 Å
R = 0.036
wR = 0.102
Data-to-parameter ratio = 14.9
Details

5-(Trifluoromethoxy)isatin

M. Schutte,^a ^* C. Pretorius,^a H.G. Visser ^a and A. Roodt ^a

^aDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein, 9301, South Africa
Correspondence e-mail: schuttem@ufs.ac.za

The title compound [systematic name: 5-(trifluoromethoxy)-1H-indole-2,3-dione], C₉H₄F₃NO₃, crystallized with two molecules in the asymmetric unit. Intermolecular N-HO hydrogen bonds link the molecules to form layers parallel to the ab plane. In addition, [pi] - [pi] stacking interactions are observed with a centroid-centroid distance of 3.721 (1) Å. The near planarity of the two isatin ring systems is illustrated by by the maximum deviations of 0.023 (1) and 0.025 (1) Å for the N atom in each case.

Related literature

For similar structures and background information on isatin as a biological agent, see Schutte et al. (2012); Garden et al. (2006); Goldschmidt & Llewellyn (1950); Frolova et al. (1988); Wei et al. (2004); Palmer et al. (1987); Akkurt et al. (2006). For reaction kinetic data on similar structures, see: Schutte et al. (2011).

Experimental

Crystal data

C₉H₄F₃NO₃
M_r = 231.13
Monoclinic, P 2₁ /n
a = 14.329 (5) Å
b = 6.082 (5) Å
c = 20.401 (5) Å
= 91.608 (5)°
V = 1777.2 (16) Å³
Z = 8
Mo K radiation
= 0.17 mm^-1
T = 100 K
0.51 × 0.18 × 0.10 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008) T_min = 0.152, T_max = 0.394
26198 measured reflections
4428 independent reflections
3513 reflections with I > 2(I)
R_int = 0.029

Refinement

R[F² > 2(F²)] = 0.036
wR(F²) = 0.102
S = 1.04
4418 reflections
297 parameters
H atoms treated by a mixture of independent and constrained refinement
_max = 0.34 e Å^-3
_min = -0.33 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
N1-H1O4ⁱ	0.84 (2)	1.99 (2)	2.7615 (18)	152.8 (18)
N2-H2O1ⁱⁱ	0.89 (2)	2.03 (2)	2.8776 (18)	157.4 (19)
N2-H2O4ⁱⁱⁱ	0.89 (2)	2.55 (2)	2.9850 (18)	111.2 (16)
C16-H16F3ⁱ	0.93	2.39	3.171 (2)	142
C18-H18O2^iv	0.93	2.47	3.327 (3)	153
Symmetry codes: (i) x, y-1, z; (ii) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iii) $[-x+{\script{1\over 2}}, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (iv) -x+1, -y+1, -z+1.

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT-Plus (Bruker, 2008); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: FY2072 ).

Acknowledgements

The University of the Free State, the Chemistry Department, the NRF and SASOL Ltd are acknowledged for funding.

References

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organic compounds