561
Ζ. Kristallogr. N C S 2 1 6 ( 2 0 0 1 ) 5 6 1 - 5 6 2
> by O l d e n b o u r g W i s s e n s c h a f t s v e r l a g , M ü n c h e n
Crystal structure of afift'-4-bromobenzaldehyde oxime, CyHeBrNO
A. D. Ward, V. R. Ward and E. R. T. Tiekink* 1
The University of Adelaide. Department of Chemistry. Australia 5005
Received May 25. 2001. CCDC-No. 1267/675
Discussion
The title compound adopts an anti conformation and is isomorphous to the 4-chloro analogue [3]. Key geometric parameters in
the structure are d(C4—Br4) = 1.904(5) Ä, J ( N 1 1 — O i l ) =
1.394(6) Ä and rf(Cll—Nil) = 1.280(6) Ä; these are equal
within experimental error to those found for the syn-isomer [2].
The major difference between the molecular structures of the
anti- and syn-isomers is found in the magnitude of the
N11-C11-C1 angle so that the angle in the tide compound of
131.2(5)° is significantly wider than that found in the sjn-isomer
of 122.2(3)° [2]; a similar disparity was noted for the chloro isomers [3], There is a difference in the mode of packing in the crystal structure so that whereas centrosymmetrically related
molecules associate via O-H—N interactions to form dimers in
the yyn-isomer [2], chains are formed in the present structure. As
can be seen from the figure, the hydroxyl-H forms a hydrogen
bonding contact with a symmetry related oxime-N: </(Hl —N11')
= 1.97 Α, Λ(011···Ν1Γ) = 2.764(6) A and the angle at HI is 172°
for symmetry operation i: 1/2—at, -y, -1/2+z.
Table 1. Data collection and handling.
Abstract
C 7 H 6 BrNO, orthorhombic, P2\2\2\ (No. 19), a = 6.608(2) Ä,
b = 23.11(1) Ä, c = 4.687(4) Ä, V= 715.8 Ä 3 , Z = 4,
Rgt(F) = 0.033, wRTtf(F2) = 0.089, T= 173 K.
Source of material
The title compound was obtained from the incomplete conversion
of p-bromobenzaldehyde into p-bromobenzonitrile as described
in the literature [ 1 ]. The isomers were partially separated by column chromatography (diethyl ether/hexane gradient). The
i_yn-isomer [2] was eluted first the anti-isomer crystallised after
slow evaporation of the eluting solvent as colourless needles.
Crystal:
Wavelength:
μ:
Diffractometer, scan mode:
2ömax:
WfcOmeasured, N(hkl)mique·
Criterion for /obs, N(hkl)gc.
N(param)Kfinca'.
Programs:
tan plate, size 0.03 χ 0.10 χ 0.37 mm
Mo Ka radiation (0.71069 A)
56.81 cm" 1
Rigaku AFC7R, ω/2θ
55°
1929, 1642
U s > 2 of/ 0 bs j, 1121
92
DIRDIF92 [4], SHELXL-97 [5],
teXsan [6], DIFABS [7], PLATON [8]
Table 2. Atomic coordinates and displacement parameters (in A 2 ).
Experimental details
The C-bound Η atoms were placed in their geometrically calculated positions and included in the final refinement in the riding
model approximation. The oxygen-Η atom was located from a
difference map. There is no inherent chirality in the molecule and
hence, no attempt was made to collect Friedel pairs for this
structure.
* Correspondence author (e-mail: [email protected])
1
Current address: National University of Singapore,
Department of Chemistry, Singapore 117543
Atom
Site
H(l)
H(2)
H(3)
H(5)
H(6)
H(ll)
4a
4a
4a
4a
4a
4a
X
y
0.1460
-0.1738
-0.4604
-0.5698
-0.2747
0.0331
-0.0019
0.1717
0.2198
0.0896
0.0423
0.0912
ζ
0.0654
0.6463
0.4826
-0.0725
0.0813
0.6729
C/iso
0.040(6)
0.040
0.040
0.040
0.040
0.040
Unauthenticated
Download Date | 6/14/17 2:43 PM
562
Ληίι-4-bromobenzaldehyde oxime
Table 3. Atomic coordinates and displacement parameters (in Ä2).
Atom
Site
Br(4)
O(ll)
N(ll)
C(l)
C(2)
C(3)
C(4)
C(5)
C(6)
C(ll)
4a
4a
4a
4a
4a
4a
4a
4a
4a
4a
X
-0.77084(7)
0,0542(5)
0.1156(6)
-0.1903(6)
-0.2515(7)
-0.4224(7)
-0.5370(7)
-0.4868(7)
-0.3116(7)
-0.0044(7)
y
ζ
0.19824(2)
0.0167(2)
0.0388(2)
0.1030(2)
0.1554(2)
0.1837(2)
0.1585(2)
0.1064(2)
0.0784(2)
0.0771(2)
0.0572(1)
0.1253(8)
0.3883(9)
0.3731(9)
0.4959(8)
0.403(1)
0.191(1)
0.071(1)
0.163(1)
0.490(1)
U,,
U22
ί/33
0.0454(3)
0.044(2)
0.040(2)
0.034(2)
0.043(2)
0.048(3)
0.036(2)
0.038(2)
0.038(3)
0.043(2)
0.0458(3)
0.050(2)
0.037(2)
0.027(2)
0.038(2)
0.028(3)
0.032(3)
0.034(3)
0.033(3)
0.034(3)
0.0460(3)
0.033(2)
0.028(3)
0.025(3)
0.024(3)
0.029(3)
0.030(3)
0.035(3)
0.032(3)
0.026(3)
U ,2
0.0142(2)
0.015(2)
0.004(2)
-0.000(2)
-0.001(2)
0.003(2)
0.002(2)
-0.002(2)
0.000(2)
0.003(2)
U,)
-0.0082(3)
-0.001(2)
-0.003(2)
0.002(2)
-0.002(2)
-0.001(2)
0.005(2)
-0.003(3)
0.004(2)
0.004(2)
t/23
-0.0046(3)
-0.005(2)
0.003(2)
0.003(2)
-0.004(2)
0.001(2)
0.007(2)
-0.003(3)
-0.003(2)
0.001(2)
Acknowledgments. The University of Adelaide, for the award of a Postgraduate Research Scholarship (V.R.W.), and the Australian Research Council are
thanked for support.
References
1. Olah, G. Α.; Keumi, T.: Synthetic Methods and Reactions; 60. Improved
One-Step Conversion of Aldehydes into Nitriles with Hydroxylamine in
Formic Acid Solution. Synth. Commun. (1979) 112-113.
2. Ward, A. D.; Ward, V. R.; Tiekink, E. R. T.: Crystal structure of
iyn-4-bromobenzaldehyde oxime, C7H6BrNO. Z. Kristallogr. NCS 216
(2001)563-564.
3. Jensen, K. G.: Crystal structure of anri-p-chlorobenzaldoxime. Acta
Chem. Scand. 24 (1970) 3293-3300.
4. Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.; Garcia-Granda, S.: The DIRDIF program system, Technical Report of the
Crystallography Laboratory, University of Nijmegen, The Netherlands,
1992.
5. Sheldrick, G. M.: SHELXL-97. Program for crystal structure refinement.
University of Göttingen, Germany 1997.
6. teXsan: Single Crystal Structure Analysis Software. Version 1.04. Molecular Structure Corporation. The Woodlands, TX, USA 1997.
7. Walker, N.; Stuart, D.: An empirical method for correcting diffractometer
data for absorption effects. Acta Crystallogr. A39 (1983) 159-166.
8. Spek, T.: PLATON, A Multipurpose Crystallographic Tool. Utrecht University, Utrecht, The Netherlands 2000.
Unauthenticated
Download Date | 6/14/17 2:43 PM