Racemic tricarbon­yl[7-meth­oxy-2-(η6-phen­yl)chromane]­chromium(0)

Gohain, M.; Muller, T.J.; Bezuidenhoudt, B.C.B.

doi:10.1107/S1600536811008683

Volume 67
Part 4
Pages m438-m439
April 2011

Received 19 February 2011
Accepted 7 March 2011
Online 12 March 2011

Key indicators
Single-crystal X-ray study
T = 100 K
Mean (C-C) = 0.002 Å
R = 0.034
wR = 0.090
Data-to-parameter ratio = 18.3
Details

Racemic tricarbonyl[7-methoxy-2-(⁶-phenyl)chromane]chromium(0)

Mukut Gohain,^a Theunis J. Muller ^a ^* and Barend C. B. Bezuidenhoudt ^a

^aDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
Correspondence e-mail: muller.theunis@gmail.com

In the title compound, [Cr(C₁₆H₁₆O₂)(CO)₃], the Cr⁰ atom of the Cr(CO)₃ unit is coordinated to the phenyl ring of the flavan ligand in an [eta] ⁶ mode, with a normal arene-to-metal distance. The Cr(CO)₃ unit exhibits a three-legged piano-stool conformation, while the dihydropyran ring displays a distorted envelope configuration. The phenyl ring is twisted away from the fused ring system by 25.5 (2)°. The methoxy group is almost coplanar with the phenyl ring [C_Me-O-C_ar-C_ar torsion angle = 8.46 (2)°]. The crystal packing is stabilized by intermolecular C-HO interactions.

Related literature

For similar structures, see: van Tonder et al. (2010a,b) and for other related structures, see: van Tonder et al. (2009a,b). For the synthesis of the title compound, see: Müller et al. (1999) and for the sythesis of 7-methoxyflavan-4-one, see: Sato et al. (2006). For standard bond lengths, see: Allen et al. (1987). For the importance of flavonoids in biological investigations, see: Rice-Evans & Packer (2003). For the use of tricarbonyl(arene)chromium complexes in regioselective organic synthesis, see: Muschalek et al. (2007).

Experimental

Crystal data

[Cr(C₁₆H₁₆O₂)(CO)₃]
M_r = 376.32
Monoclinic, P 2₁ /c
a = 9.7703 (5) Å
b = 19.1820 (9) Å
c = 8.8049 (4) Å
= 97.494 (2)°
V = 1636.07 (14) Å³
Z = 4
Mo K radiation
= 0.73 mm^-1
T = 100 K
0.34 × 0.23 × 0.08 mm

Data collection

Bruker X8 APEXII 4K KappaCCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008) T_min = 0.818, T_max = 0.942
29057 measured reflections
4069 independent reflections
3526 reflections with I > 2(I)
R_int = 0.033

Refinement

R[F² > 2(F²)] = 0.034
wR(F²) = 0.090
S = 1.00
4069 reflections
222 parameters
H-atom parameters constrained
_max = 0.73 e Å^-3
_min = -0.52 e Å^-3

Table 1
Hydrogen-bond geometry (Å, °)

D-HA	D-H	HA	DA	D-HA
C4'-H4'O2ⁱ	0.93	2.54	3.459 (2)	169
C2'-H2'O4ⁱⁱ	0.93	2.46	3.153 (2)	132
C1-H1CO4ⁱⁱⁱ	0.96	2.57	3.314 (2)	134
Symmetry codes: (i) $[-x, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (ii) $[x, -y-{\script{1\over 2}}, z+{\script{1\over 2}}]$ ; (iii) $[-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

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 (Brandenberg & 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: HP2002 ).

Acknowledgements

The University of the Free State and Sasol Ltd are gratefully acknowledged for financial support and Johannes van Tonder for the NMR data and help with the synthesis of the title compound. Special thanks are due to Prof Andreas Roodt.

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.
Brandenberg, K. & Putz, H. (2005). DIAMOND. Crystal Impact GbR, Bonn, Germany.
Bruker (2008). APEX2, SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.
Müller, T. J. J., Ansorge, M. & Polburn, K. (1999). J. Organomet. Chem. 578, 252-259.
Muschalek, B., Weidner, I. & Butenschön, H. (2007). J. Organomet. Chem. 692, 2415-2424.
Rice-Evans, C. A. & Packer, L. (2003). Flavonoids in Health and Disease, Vol. 578, 2nd ed., pp. 252-259. New York: Marcel Dekker Inc.
Sato, S., Hiroe, K., Kumazawa, T. & Jun-ichi, O. (2006). Carbohydr. Res. 341, 1091-1095.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
Tonder, J. H. van, Bezuidenhoudt, B. C. B. & Janse van Rensburg, J. M. (2009a). Acta Cryst. E65, m1343.
Tonder, J. H. van, Bezuidenhoudt, B. C. B. & Janse van Rensburg, J. M. (2009b). Acta Cryst. E65, m1346.
Tonder, J. H. van, Bezuidenhoudt, B. C. B. & Janse van Rensburg, J. M. (2010a). Acta Cryst. E66, m907-m908.
Tonder, J. H. van, Bezuidenhoudt, B. C. B. & Janse van Rensburg, J. M. (2010b). Acta Cryst. E66, m1086.

metal-organic compounds

Racemic tricarbonyl[7-methoxy-2-(6-phenyl)chromane]chromium(0)