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Volume 69 
Part 3 
Page m147  
March 2013  

Received 24 November 2012
Accepted 4 February 2013
Online 13 February 2013

Key indicators
Single-crystal X-ray study
T = 173 K
Mean [sigma](C-C) = 0.003 Å
R = 0.036
wR = 0.107
Data-to-parameter ratio = 31.8
Details
Open access

catena-Poly[[(tetrahydrofuran-[kappa]O)potassium]-di-[mu]-dimethylamido-[kappa]4N:N-aluminium-di-[mu]-dimethylamido-[kappa]4N:N-potassium-di-[mu]-dimethylamido-[kappa]4N:N-aluminium-di-[mu]-dimethylamido-[kappa]4N:N]

aNaval Research Laboratory, 4555 Overlook Av, SW, Washington, DC 20375, USA
Correspondence e-mail: andrew.purdy@nrl.navy.mil

The title compound, [Al2K2(C2H6N)8(C4H8O)]n, formed during the sonochemical reaction between Al(NMe2)3 and sodium-potassium alloy in the presence of tetrahydrofuran (THF). Its asymmetric unit has two inequivalent K+ sites. One site is coordinated by a THF ligand, and crystallizes as a one-dimensional polymer with a backbone of catenated AlN2K rings. A twofold rotation axis bisects one K+ site and the THF ligand; the second K+ site is situated on an inversion centre, resulting in a planar four-coordination by N atoms. The latter symmetry operation generates the second half of the THF molecule and fills out the coordination sphere of the potassium sites. The chains extend along the c-axis direction and zigzag at the THF-coordinated K+ sites by an angle of 106.02 (5)°.

Related literature

Several (RR'N)4AlM (M = Li, Na) compounds that have catenated AlN2M chains have been reported previously (Eisler & Chivers, 2006[Eisler, D. J. & Chivers, T. (2006). Can. J. Chem. 84, 443-452.]); Rings et al. 2000[Rings, S., Ischenko, V. & Jansen, M. (2000). Z. Naturforsch Teil B, 55, 730-734.]). The structure of tris(dimethylamino)aluminium is a molecular dimer, see: Ouzounis et al. (1983[Ouzounis, K., Riffel, H., Hess, H., Kohler, U. & Weidlein, J. (1983). Z. Anorg. Allg. Chem. 504, 67-76.]). Heavily solvated tetraaminoalanates tend to have separated cations instead of catenated chain structures, see: Hensen et al. (1999[Hensen, K., Lemke, A., Stumpf, T., Bolte, M., Fleischer, H., Pulham, C. R., Gould, R. O. & Harris, S. (1999). Inorg. Chem. 38, 4700-4704.]). For details of the synthesis, see: Ruff (1960[Ruff, J. K. (1960). J. Am. Chem. Soc. 83, 2835-2839.]); Ouzounis et al. (1983[Ouzounis, K., Riffel, H., Hess, H., Kohler, U. & Weidlein, J. (1983). Z. Anorg. Allg. Chem. 504, 67-76.]).

[Scheme 1]

Experimental

Crystal data
  • [Al2K2(C2H6N)8(C4H8O)]

  • Mr = 278.44

  • Monoclinic, C 2/c

  • a = 13.247 (4) Å

  • b = 12.075 (4) Å

  • c = 20.822 (7) Å

  • [beta] = 90.979 (5)°

  • V = 3330.1 (19) Å3

  • Z = 8

  • Mo K[alpha] radiation

  • [mu] = 0.36 mm-1

  • T = 173 K

  • 0.74 × 0.57 × 0.42 mm

Data collection
  • Bruker SMART APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2008[Bruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.776, Tmax = 0.863

  • 18795 measured reflections

  • 4928 independent reflections

  • 3986 reflections with I > 2[sigma](I)

  • Rint = 0.023

Refinement
  • R[F2 > 2[sigma](F2)] = 0.036

  • wR(F2) = 0.107

  • S = 1.03

  • 4928 reflections

  • 155 parameters

  • H-atom parameters constrained

  • [Delta][rho]max = 0.25 e Å-3

  • [Delta][rho]min = -0.30 e Å-3

Data collection: APEX2 (Bruker, 2008[Bruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2008[Bruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: NK2195 ).


Acknowledgements

We thank The Office of Naval Research for financial support.

References

Bruker (2008). APEX2, SADABS and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Eisler, D. J. & Chivers, T. (2006). Can. J. Chem. 84, 443-452.  [ISI] [CSD] [CrossRef] [ChemPort]
Hensen, K., Lemke, A., Stumpf, T., Bolte, M., Fleischer, H., Pulham, C. R., Gould, R. O. & Harris, S. (1999). Inorg. Chem. 38, 4700-4704.  [ISI] [CSD] [CrossRef] [PubMed] [ChemPort]
Ouzounis, K., Riffel, H., Hess, H., Kohler, U. & Weidlein, J. (1983). Z. Anorg. Allg. Chem. 504, 67-76.  [CrossRef] [ChemPort]
Rings, S., Ischenko, V. & Jansen, M. (2000). Z. Naturforsch Teil B, 55, 730-734.  [ChemPort]
Ruff, J. K. (1960). J. Am. Chem. Soc. 83, 2835-2839.  [CrossRef] [ISI]
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]


Acta Cryst (2013). E69, m147  [ doi:10.1107/S1600536813003553 ]

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