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Volume 69 
Part 12 
Page m654  
December 2013  

Received 29 October 2013
Accepted 6 November 2013
Online 13 November 2013

Key indicators
Single-crystal X-ray study
T = 296 K
Mean [sigma](C-C) = 0.007 Å
R = 0.028
wR = 0.061
Data-to-parameter ratio = 17.3
Details
Open access

Tetra­chlorido­[N2,N2'-(di­methyl­silanedi­yl)bis­(N-tert-butyl-3-methyl­benzimid­amid­ato)-[kappa]2N2,N2']hafnium(IV)

aInstitute of Applied Chemistry, Shanxi University, Taiyuan 030006, People's Republic of China
Correspondence e-mail: wangtao4913@126.com

The symmetric title mol­ecule, [Hf(C26H40N4Si)Cl4], lies about a twofold rotation axis. The HfIV and Si atoms lie on the rotation axis with all other atoms being in general positions. The HfIV atom is six-coordinated by two N atoms from the N2,N2'-(di­methyl­silanedi­yl)bis­(N-tert-butyl-3-methyl­benz­imid­amidate) ligand and four Cl- ions in a slightly distorted octa­hedral geometry. The two amidinate moieties are connected through the central Si atom with Si-N bond length of 1.762 (3) Å, generating the characteristic N-C-N-Si-N-C-N skeleton of a silyl-linked ansa-bis­(amidine) species.

Related literature

For reviews of related amidinate ligands and their applications, see: Edelmann (2012[Edelmann, F. T. (2012). Chem. Soc. Rev. 41, 7657-7672.]); Lei et al. (2011[Lei, Y. L., Chen, F., Luo, Y. J., Xu, P. & Wang, Y. R. (2011). Inorg. Chim. Acta, 368, 179-186.]); Münch et al. (2008[Münch, M., Flörke, U., Bolte, M., Schulz, S. & Gudat, D. (2008). Angew. Chem. Int. Ed. 47, 1512-1514.]). For a review of the modification of the steric and electronic properties of amidinate ligands by varying their substitution patterns, see: Liu et al. (2013[Liu, R.-Q., Bai, S.-D. & Wang, T. (2013). Acta Cryst. E69, o520.]); Qian et al. (2010[Qian, F., Liu, K. Y. & Ma, H. Y. (2010). Dalton Trans. 39, 8071-8083.]). For related silyl-linked bis(amidinate) ligands and the synthesis of their metal complexes, including a closely related Hf complex, see: Bai et al. (2013[Bai, S. D., Liu, R. Q., Wang, T., Guan, F., Wu, Y. B., Chao, J. B., Tong, H. B. & Liu, D. S. (2013). Polyhedron, 65, 161-169.]).

[Scheme 1]

Experimental

Crystal data
  • [Hf(C26H40N4Si)Cl4]

  • Mr = 757

  • Monoclinic, C 2/c

  • a = 9.4373 (14) Å

  • b = 17.992 (3) Å

  • c = 19.966 (3) Å

  • [beta] = 103.276 (3)°

  • V = 3299.5 (8) Å3

  • Z = 4

  • Mo K[alpha] radiation

  • [mu] = 3.54 mm-1

  • T = 296 K

  • 0.08 × 0.05 × 0.05 mm

Data collection
  • Bruker SMART area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.765, Tmax = 0.843

  • 7121 measured reflections

  • 2920 independent reflections

  • 2446 reflections with I > 2[sigma](I)

  • Rint = 0.035

Refinement
  • R[F2 > 2[sigma](F2)] = 0.028

  • wR(F2) = 0.061

  • S = 1.02

  • 2920 reflections

  • 169 parameters

  • H-atom parameters constrained

  • [Delta][rho]max = 0.53 e Å-3

  • [Delta][rho]min = -0.29 e Å-3

Table 1
Selected bond lengths (Å)

Hf1-N2 2.233 (3)
Hf1-Cl2 2.4261 (11)
Hf1-Cl1 2.4366 (11)
Hf1-Si1 3.0588 (16)
Si1-N2 1.762 (3)
Si1-C13 1.857 (5)
N1-C5 1.318 (5)
N1-C1 1.504 (5)
N1-H1 0.8600

Data collection: SMART (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2000[Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL/PC (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXL97.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ5366 ).


Acknowledgements

We acknowledge financial support by the Natural Science Foundation of China (20702029) and the Natural Science Foundation of Shanxi Province (2008011024).

References

Bai, S. D., Liu, R. Q., Wang, T., Guan, F., Wu, Y. B., Chao, J. B., Tong, H. B. & Liu, D. S. (2013). Polyhedron, 65, 161-169.  [CSD] [CrossRef] [ChemPort]
Bruker (2000). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Edelmann, F. T. (2012). Chem. Soc. Rev. 41, 7657-7672.  [Web of Science] [CrossRef] [ChemPort] [PubMed]
Lei, Y. L., Chen, F., Luo, Y. J., Xu, P. & Wang, Y. R. (2011). Inorg. Chim. Acta, 368, 179-186.  [Web of Science] [CSD] [CrossRef] [ChemPort]
Liu, R.-Q., Bai, S.-D. & Wang, T. (2013). Acta Cryst. E69, o520.  [CSD] [CrossRef] [IUCr Journals]
Münch, M., Flörke, U., Bolte, M., Schulz, S. & Gudat, D. (2008). Angew. Chem. Int. Ed. 47, 1512-1514.
Qian, F., Liu, K. Y. & Ma, H. Y. (2010). Dalton Trans. 39, 8071-8083.  [CSD] [CrossRef] [ChemPort] [PubMed]
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [ChemPort] [IUCr Journals]


Acta Cryst (2013). E69, m654  [ doi:10.1107/S1600536813030328 ]

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