563
Ζ. Kristallogr. NCS 216 (2001) 563-564
© by Oldenbourg Wissenschaftsverlag, München
Crystal structure of syn-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. 1267/676
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 O-H atom was located from a difference map.
Discussion
The title compound is isomorphous to the 4-chloro analogue [2,
3] and adopts a syn conformation. Key geometric parameters in
the structure are <f(C4—Br4) = 1.903(3) Α, d ( N l l — O i l ) =
1.409(3) A and </(Cll—Nil) = 1.269(4) A. These parameters
match those found in the an/i'-isomer [4]. The major difference
between the geometric parameters for the isomers is found in the
N11-C11-C1 angle which at 122.2(3)° in the present structure is
significantly reduced compared to 131.2(5)° found in the antiisomer [4]. This feature was noted previously for the isomeric
chloro analogues [5]. Centrosymmetrically related molecules associate via O-H—Ν interactions as shown in the figure. Hydrogen-bonding parameters: d ( 0 - H l 1--N11') = 1.94 A,
d{0\ 1-N11') = 2.820(5) A and angle at Η is 162° for symmetry
operation i: \-x-2-y-zThis mode of association contrasts that
for the an/i-isomer where chains are formed [4].
Table 1. Data collection and handling.
Crystal:
Wavelength:
colourless plate, size 0.05 χ 0.24 χ 0.32 mm
Mo Ka radiation (0.71069 A)
54.96 cm"1
Rigaku AFC7R, ω/2θ
55°
3347, 1675
μ:
Diffractometer, scan mode:
20max:
WAWJmeasured, N(hkl)Umque·
C r i t e r i o n f o r Iabs, Nfhkl)^:
/obs > 2 a(lobi), 1262
N(param)rc fined:
92
DIRDIF92 [6], SHELXL-97 [7],
teXsan [8], DIFABS [9], PLATON [10]
Programs:
Abstract
C7H6BrNO, monoclinic, P\2\lc\ (No. 14), a = 6.161(4) Ä,
b = 4.766(6) A, c = 25.187(3) Ä, β = 94.00(3)°, V= 737.8 Ä 3 ,
Ζ = 4, Rgi(F) = 0.027, wRKf(F2)
= 0.072, T=
173 K.
Table 2. Atomic coordinates and displacement parameters (in Ä2).
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
jyn-isomer was eluted first and gave colourless plate-like crystals
after slow evaporation of the eluting solvent.
Atom
Site
X
H(l)
H(2)
H(3)
H(5)
H(6)
4e
4e
4e
4e
4e
4e
0.6659
0.7380
0.5262
0.0391
0.2511
0.8014
H(ll)
* Correspondence author (e-mail: [email protected])
1
Current address: National University of Singapore,
Department of Chemistry, Singapore 117543
y
-1.0570
-0.3855
-0.0693
-0.1477
-0.4675
-0.6772
ζ
-0.0009
0.1719
0.2176
0.1011
0.0565
0.0971
i/iso
0.039(4)
0.039
0.039
0.039
0.039
0.039
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564
Syn-4-bromobenzaldehyde oxime
Table 3. Atomic coordinates and displacement parameters (in Ä 2 ).
Atom
Site
jr
Br(4)
O(ll)
N(ll)
C(l)
C(2)
C(3)
C(4)
C(5)
C(6)
C(ll)
4e
4e
4e
4e
Ae
4e
4e
Ae
4e
4e
0.09301(4)
0.7490(3)
0.5840(4)
0.5140(4)
0.5955(5)
0.4708(5)
0.2641(4)
0.1801(5)
0.3068(5)
0.6537(5)
>•
0.16374(6)
-0.9805(5)
-0.8074(5)
-0.4592(6)
-0.3388(6)
-0.1512(6)
-0.0871(6)
-0.1988(6)
-0.3871(6)
-0.6587(6)
;
U\\
U22
i/33
U\2
0.20194(1)
0.02672(8)
0.04471(9)
0.1100(1)
0.1578(1)
0.1851(1)
0.1635(1)
0.1156(1)
0.0892(1)
0.0841(1)
0.0299(2)
0.041(1)
0.034(1)
0.029(1)
0.028(1)
0.030(1)
0.028(1)
0.025(1)
0.032(1)
0.030(1)
0.0299(2)
0.046(1)
0.031(1)
0.021(1)
0.031(2)
0.028(1)
0.022(1)
0.029(2)
0.030(2)
0.030(1)
0.0287(2)
0.032(1)
0.027(1)
0.027(1)
0.029(1)
0.028(1)
0.024(1)
0.028(1)
0.023(1)
0.031(1)
0.0047(1)
0.020(1)
0.009(1)
-0.000(1)
0.004(1)
0.000(1)
0.003(1)
0.003(1)
-0.001(1)
0.004(1)
U13
0.0023(1)
-0.0015(9)
0.0014(9)
-0.001(1)
-0.007(1)
-0.006(1)
0.003(1)
-0.004(1)
-0.005(1)
-0.003(1)
Uiy
-0.0010(1)
-0.009(1)
-0.002( 1)
0.001(1)
-0.001(1)
-0.005( 1)
0.002(1)
0.002( 1)
-0.003(1)
-0.001(1)
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
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AZ-methyl-p-chlorobenzaidoxime and refinement of the structures of 'syn'
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1263-1275.
3. Arte, E.; Declercq, J. P.; Germain, G.; van Meerssche, M.: New structure
determination of p-chlorobenzaldoxime. Bull. Soc. Chim. Belg. 89 (1980)
155-156.
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απ/ι-4-bromobenzaldehyde oxime, C7H6BrNO. Z. Kristallogr. NCS 216
(2001)561-562.
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Chem. Scand. 24 (1970) 3293-3300.
6. Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.; Garcia-Granda, S.: The DIRDIF program system. Technical Report of the
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University of Göttingen, Germany 1997.
8. teXsan: Single Crystal Structure Analysis Software. Version 1.04. Molecular Structure Corporation. The Woodlands, TX, USA 1997.
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data for absorption effects. Acta Crystallogr. A39 (1983) 159-166.
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