3
d = 0.85–1.11 (m, br, 24H, iPrN), 1.17 (d, JH–H = 6.8 Hz, 6H,
could be separated well. The unit cell contains a highly disordered
hexane molecule located on the inversion center. This disorder was
iPr), 1.19 (d, 3JH–H = 6.8 Hz, 6H, iPr), 1.28–1.34 (m, br, 12H, iPr),
1.69 (s, 6H, Me backbone), 1.84 (br, 6H, BH3), 1.87 (s, 6H, Me
treated by the SQUEEZE procedure incorporated in PLATON
backbone), 3.09 (sept, JH–H = 6.8 Hz, 2H, iPr), 3.23 (sept, JH–H
= 6.8 Hz, 2H, iPr), 3.34(br, 2H, iPrN), 3.44 (br, 2H, iPrN), 4.93
(194 A , 36 e).15 Disorder in some of the iPr groups was treated by
3
3
3
˚
refinement with enlarged anisotropic thermal parameters.
3
(s, 2H, H backbone), 5.24 (br, 2H, BH), 6.16 (d, JH–H = 7.4 Hz,
(META-Mg)2. Measurement at -170 ◦C (Mo-Ka), formula
[C80H104Mg2N8, 3(C6H6)], Mw = 1460.71, monoclinic, a =
2H, aryl), 6.97–7.13 (m, 7H, aryl), 7.51 (s, 1H, aryl). 11B NMR
◦
(160 MHz, benzene-d6], 20 C): d = -22.00 (br, 2B, BH3), 39.44
˚
˚
˚
19.0122(13) A, b = 22.8562(15) A, c = 20.8328(14) A, b =
◦
(br, 2B, BH). 13C NMR (75 MHz, benzene-d6, 20 C): 24.0 (Me
◦
3
˚
110.058(2) , V = 8503.7(10) A , space group P21/n, Z = 4,
backbone), 24.0 (iPrN), 24.4 (iPrN), 24.8 (Me backbone), 24.8
(iPr), 24.9 (iPr), 25.1 (iPr), 25.6 (iPr), 27.8 (iPrN), 28.7 (iPr), 29.3
(iPr), 29.5 (iPrN), 48.2 (iPrN), 53.7 (iPrN), 97.2 (backbone), 120.1
(aryl), 121.3 (aryl), 124.4 (aryl), 124.5 (aryl), 126.1 (aryl), 131.2
(aryl), 142,7 (aryl), 142.9 (aryl), 145.5 (aryl), 152.9 (aryl), 167.2
(backbone), 170.5 (backbone).
rc = 1.141 g cm-3, m(Mo-Ka) = 0.079 mm-1, 53 133 measured
reflections, 14 249 independent reflections (Rint = 0.056), 8481
reflections observed with I > 2s(I), qmax = 24.8◦, R = 0.0476,
wR2 = 0.1288, GOF = 0.96, 943 parameter, min/max residual
-3
˚
electron density -0.29/+0.25 e A . Hydrogen atoms have been
placed on calculated positions and were refined in a riding
mode. The asymmetric unit contains three cocrystallized benzene
molecules of which two could be refined. The third molecule is
highly disordered and was treated by the SQUEEZE procedure
(META-Mg)2. Elemental analysis (%) calcd for C80H104Mg2N8
11
(Mr = 1226.38): C 78.35, H 8.55; found C 78.20, H 8.43. 1H{ B}
NMR (500 MHz, benzene-d6, 20 ◦C): d = 0.25 (d, 3JH-H = 6.7 Hz,
3
15
3
3
˚
incorporated in PLATON (156 A , 41 e).
3H, iPr), 0.96 (d, JH–H = 6.7 Hz, 3H, iPr), 1.14 (d, JH–H
=
3
3
Crystallographic data (excluding structure factors) have been
deposited with the Cambridge Crystallographic Data Centre as
supplementary publication no. CCDC 822039–822040.†
6.9 Hz, 3H, iPr), 1.26 (d, JH–H = 6.7 Hz, 3H, iPr), 1.27 (d, JH–H
3
= 6.9 Hz, 3H, iPr), 1.35 (d, JH–H = 6.9 Hz, 3H, iPr), 1.38 (d,
3JH–H = 6.9 Hz, 3H, iPr), 1.55 (d, JH–H = 6.7 Hz, 3H, iPr), 1.58
3
(s, 3H, Me backbone), 1.70 (s, 3H, Me backbone), 1.72 (s, 3H,
3
Me backbone), 1.85 (s, 3H, Me backbone), 2.49 (sept, JH–H
=
Acknowledgements
3
6.9 Hz, 1H, iPr), 3.33 (sept, JH–H = 6.7 Hz, 1H, iPr), 3.37 (sept,
3JH–H = 6.9 Hz, 1H, iPr), 3.53 (sept, 3JH–H = 6.9 Hz, 1H, iPr), 4.66
The DFG is gratefully acknowledged for financial support. Prof.
R. Boese and D. Bla¨ser are thanked for measuring X-ray data and
H. Bandmann for measuring the 500 MHz NMR spectra.
3
(s, 1H, H backbone), 4.89 (s, 1H, H backbone), 5.02 (dd, JH–H
4
3
= 7.8 Hz, JH–H = 1.8 Hz, 1H, aryl), 6.02 (dd, JH–H = 7.8 Hz,
4JH–H = 1.8 Hz, 1H, aryl), 6.55 (t, JH–H = 7.8 Hz, 1H, aryl), 6.84
3
(t, JH–H = 1.8 Hz, 1H, aryl), 7.02–7.30 (m, 6H, aryl). 13C NMR
4
Notes and references
(75 MHz, benzene-d6, 20 ◦C): 23.8 (Me backbone), 24.0 (iPr), 24.5
(Me backbone), 24.5 (iPr), 24.9 (Me backbone), 25.3 (iPr), 25.6
(Me backbone), 26.2 (iPr), 26.9 (iPr), 27.9 (iPr), 28.9 (iPr), 29.5
(iPr), 30.2 (iPr), 95.3 (backbone), 102.7 (backbone), 119.1 (aryl),
120.1 (aryl), 121.4 (aryl), 123.8 (aryl), 123.9 (aryl), 124.3 (aryl),
125.2 (aryl), 125.5 (aryl), 125.8 (aryl), 129.4 (aryl), 142.8 (aryl),
142.9 (aryl), 143.0 (aryl), 143.2 (aryl), 145.8 (aryl), 147.4 (aryl),
150.1 (aryl), 151.4 (aryl), 166.1 (backbone), 168.6 (backbone),
170.2 (backbone) 170.4 (backbone).
1 H. I. Schlesinger and A. B. Burg, J. Am. Chem. Soc., 1938, 60, 290–299.
2 (a) G. B. Fischer, J. C. Fuller, J. Harrison, S. G. Alvarez, E. R.
Burkhardt, C. T. Goralski and B. Singaram, J. Org. Chem., 1994, 59,
6378–6385; (b) L. Pasumansky, C. T. Goralski and B. Singaram, Org.
Process Res. Dev., 2006, 10, 959–970.
3 (a) H. V. K. Diyabalanage, R. P. Shrestha, T. A. Semelsberger, B. L.
Scott, M. E. Bowden, B. L. Davis and A. K. Burrell, Angew. Chem.,
Int. Ed., 2007, 46, 8995–8997; (b) Z. T. Xiong, C. K. Yong, G. T. Wu, P.
Chen, W. Shaw, A. Karkamkar, T. Autrey, M. O. Jones, S. R. Johnson,
P. P. Edwards and W. I. F. David, Nat. Mater., 2008, 7, 138–141; (c) X. D.
Kang, Z. Z. Fang, L. Y. Kong, H. M. Cheng, X. D. Yao, G. Q. Lu and
P. Wang, Adv. Mater., 2008, 20, 2756–2759; (d) H. Wu, W. Zhou and T.
Yildirim, J. Am. Chem. Soc., 2008, 130, 14834–14839; (e) Z. T. Xiong,
G. T. Wu, Y. S. Chua, J. J. Hu, T. He, W. L. Xu and P. Chen, Energy
Environ. Sci., 2008, 1, 360–363; (f) Y. S. Chua, G. T. Wu, Z. T. Xiong, T.
He and P. Chen,, Chem. Mater., 2009, 21, 4899–4904; (g) Q. A. Zhang,
C. X. Tang, C. H. Fang, F. Fang, D. L. Sun, L. Z. Ouyang and M. Zhu,
J. Phys. Chem. C, 2010, 114, 1709–1714.
Crystal structure determination
The structures were solved by Direct Methods (SHELXS-97)15
and refined with SHELXL-97.16 All geometry calculations and
graphics were performed with PLATON.17
4 (a) T. B. Marder, Angew. Chem., 2007, 119, 8262–8264, (Angew. Chem.,
Int. Ed., 2007, 46, 8116); (b) F. H. Stephens, R. T. Baker, M. H. Matus,
D. J. Grant and D. A. Dixon, Angew. Chem., Int. Ed., 2007, 46, 746–
749; (c) F. H. Stephens, V. Pons and R. T. Baker, Dalton Trans., 2007,
2613–2626.
5 (a) G. Wolf, J. Baumann, F. Baitalow and F. P. Hoffmann, Thermochim.
Acta, 2000, 343, 19–25; (b) F. Baitalov, J. Baumann, G. Wolf, K.
Jaenicke-Ro¨ßler and G. Leitner, Thermochim. Acta, 2002, 391, 159–
168.
6 J. Spielmann, G. Jansen, H. Bandmann and S. Harder, Angew. Chem.,
Int. Ed., 2008, 47, 6290–6295.
7 J. Spielmann and S. Harder, J. Am. Chem. Soc., 2009, 131, 5064–
5065.
META-Mg3[iPrNB(H)N(iPr)BH3]2. Measurement at -130 ◦C
(Mo-Ka), formula [(C52H88B4Mg3N8), 0.5(C6H14)], Mw = 984.59,
˚
˚
˚
triclinic, a = 10.9417(12) A, b ◦= 16.6877(18) A, c = 17.8037(19) A,
◦
◦
3
˚
a = 93.865(7) , b = 106.518(7) , g = 103.888(7) , V = 2993.2(6) A ,
-3
-1
¯
space group P1, Z = 2, rc = 1.142 g cm , m(Mo-Ka) = 0.094 mm ,
49 723 measured reflections, 11 850 independent reflections (Rint
=
0.123), 6583 reflections observed with I > 2s(I), qmax = 26.1◦, R
= 0.0778, wR2 = 0.2166, GOF = 0.95, 656 parameter, min/max
-3
˚
residual electron density -0.50/+0.60 e A . Hydrogen atoms have
been placed on calculated positions, except for those attached to
B which have been located in the difference-Fourier map and were
refined isotropically. The somewhat poor crystal quality is due
to twinning of the crystal. The reflexes belonging to one domain
8 J. Spielmann, D. F.-J. Piesik and S. Harder, Chem.–Eur. J., 2010, 16,
8307–8318.
9 D. Y. Kim, N. J. Singh, H. M. Lee and K. S. Kim, Chem.–Eur. J., 2009,
15, 5598–5604.
8318 | Dalton Trans., 2011, 40, 8314–8319
This journal is
The Royal Society of Chemistry 2011
©