far more variable and significantly longer than those found in the
a = 8.06670(10), b = 28.5622(3), c = 14.5669(2) A˚ , b = 92.7395(5), V =
14
3352.42(7) A˚ , m(Mo-Ka) = 1.151 mm , r = 1.335 Mg m , T = 180(2)
3
-1
-3
˚
calc
anions of 2 or 3 (typically 2.59–3.26 A).
In conclusion, the reactions of dithiols with Sn bases Sn(NR
K. Total reflections 42 629, unique 4765 (Rint = 0.055). R1 = 0.064 [I>2s(I)]
II
)
2 2
and wR2 = 0.197 (all data). For 3, the data was very poor at high angles,
prove to be more complicated than expected, with the products
being influenced by the R-group present and the consequent redox
stability and basicity of the reagents used. These results have
potential implications for the synthesis of a broad range of related
stannylenes.
which was removed during refinements. Of the two [H NMe ] cations
+
2
2
present, one is disordered over three positions (ratio 45% : 35% : 20%). One
of the [MeC ] groups is also disordered over two positions, refined as
6
3 2
H S
having 50% occupancy in each. A small residue peak (1.49 e) is found
within 1.0 A˚ of Sn(1), there may be a small component of the compound
co-crystallising in a second orientation (this was not modelled). Data
were collected on a Nonius KappaCCD diffractometer, solved by direct
2
methods and refined by full-matrix least squares on F (G. M. Sheldrick,
Notes and references
SHELX-97, G o¨ ttingen, 1997).
‡
All manipulations were undertaken under dry, O
2
-free argon. Freshly
1 W. P. Neumann, Chem. Rev., 1991, 91, 311; N. Takeda, N. Tokitoh
and R. Okazaki, Sci. Synth., 2003, 5, 311; N. Tokitoh and R. Okazaki,
Coord. Chem. Rev., 2000, 210, 251.
2 M. F. Lappert and R. S. Rowe, Coord. Chem. Rev., 1990, 100, 267; M.
S. Holt, W. L. Wilson and J. H. Nelson, Chem. Rev., 1989, 89, 11; M.
F. Lappert and P. P. Power, J. Chem. Soc., Dalton Trans., 1985, 51; M.
Veith and O. Recktenwald, Top. Curr. Chem., 1982, 104, 1; T. Fjeldberg,
H. Hope, M. F. Lappert, P. P. Power and A. J. Thorne, J. Chem. Soc.,
Chem. Commun., 1983, 639.
3 D. Eisler, R. L. Less, V. Naseri, J. M. Rawson and D. S. Wright, Dalton
Trans., 2008, 2382.
4 F. Garc ´ı a, R. L. Less, V. Naseri, M. McPartlin, J. M. Rawson and D. S.
Wright, Angew. Chem., Int. Ed., 2007, 46, 7827; F. Garc ´ı a, R. J. Less, V.
Naseri, M. McPartlin, J. M. Rawson and D. S. Wright, Dalton Trans.,
2008, 997.
5 W. W. Schoeller and D. Eisner, Inorg. Chem., 2004, 43, 2585.
6 A. V. Zabula, T. Pape, F. Hupka, A. Hepp and F. E. Hahn,
Organometallics, 2009, 28, 4221.
7 R. O. Day, J. M. Holmes, S. Shafieezad, V. Chandrasekhar and R. R.
Holmes, J. Am. Chem. Soc., 1988, 110, 5377; F. de Assis, G. M. Chohan,
R. A. Howie, A. Khan, J. N. Low, G. M. Spencer, J. L. Wardell and S.
M. S. V. Wardell, Polyhedron, 1999, 18, 3533; T. Sheng, X. Wu, P. Lin,
Q. Wang, W. Zhang and L. Chen, L., J. Coord. Chem., 1999, 48, 113; T.
Akasaka, M. Nakano, H. Tamura and G. Matsubayashi, Bull. Chem.
Soc. Jpn., 2002, 75, 2621.
obtained samples of the dithiols were obtained from Aldrich Chemical
Company.
§
Synthesis of 2; A solution of Sn(NMe
2
)
2
(180 mg, 0.87 mmol) in thf (3 ml)
was added to a solution of benzene-1,2-dithiol (0.1 ml, 0.87 mmol) in thf
◦
(
5 ml) at -78 C. A yellow solution containing a faint, grey precipitate
was formed (assumed to be Sn metal, estimated ca. 50 mg). The solution
was filtered through Celite to give a clear yellow solution. The solvent was
removed in vacuo and the residue was redissolved in MeCN (3 ml). Storage
of the solution at room temperature for 1 h afforded yellow crystals of 2.
◦
Yield 130 mg, 0.21 mmol, 72% (based on dithiol supplied). M. pt. 184 C.
IR (Nujol, NaCl windows), n/cm = 3366 m (broad vN–H), 1712 w, 1553
w, 1436 s, 1256 m, 1241 m, 1095 m, 1037 s, 993 s, 904 s, 748 s, 653 m. H
-1
1
◦
NMR (500.2 MHz, d
8
-thf, +25 C): d/ppm = 6.67–7.86 (m, 12H, Ar H),
13
2
.66 (s, 6H, –CH
8
2
), 2.51 (s, 6H, –CH
-thf, +25 C): 148 (Ar), 131 (Ar), 121 (Ar), 40 (N–CH
3
): C NMR (125.7 MHz, d/ppm,
◦
119
d
3
): Sn NMR
-benzene): -369.2
s). Elemental analysis, found C 42.8; H 4.7; N 5.0, cald. for 2 C 41.8; H 4.5;
◦
(
(
8 4 6
186.5 MHz, d/ppm, d -thf, +25 C, rel. to SnMe in d
2-
N 4.4. Negative ion MS, m/z 269.9139 (cald. 269.9148) [M] , 540.8394
(
-
cald. 540.8369) [MH] , correct isotope patterns for both.
Synthesis of 3; A solution of Sn(NMe (315 mg, 1.50 mmol) in thf (5 ml)
was added to a solution of toluene-3,4-dithiol (0.2 ml, 1.50 mmol) in thf
3 ml) at room temperature. A yellow solution containing a faint, grey
2 2
)
(
precipitate was formed (assumed to be Sn metal, estimated ca. 50 mg). The
solution was filtered through Celite to give a clear yellow solution. Storage
of the solution at room temperature for 1 h afforded yellow crystals of 2.
Yield 315 mg, 0.47 mmol, 94% (based on dithiol supplied). M. pt. 182 C.
IR (Nujol, NaCl windows), n/cm = IR (Nujol mull): 3384 m (broad nN–
H), 1715 m, 1583 m, 1260 m, 1104 m, 1036 m, 866 m, 804 m. H NMR
8 The identity of 4 was obtained from elemental (C,H) analysis alone.
9 E. Hoyer, W. Dietzsch, H. Hennig and W. Schroth, Chem. Ber., 1962,
102, 603.
◦
-1
1
10 J. M. Kisenyi, G. R. Willey, M. G. B. Drew and S. O. Wandiga, J. Chem.
◦
3
(
500.2 MHz, d
8
-thf, +25 C), d/ppm = 7.24 (d, 3H, Ar H, JHH = 7.8 Hz),
Soc., Dalton Trans., 1985, 69.
3
14/15
7
.30 (s, 3H, Ar H), 6.62 (d, 3H, Ar H, JHH = 7.8 Hz), 2.86 (s, broad,
11
N NMR spectroscopy and PES measurements have suggested
previously that silyl and alkyl substituents can have a large effect on the
electron density in nitrogen-containing compounds, see for example: J.
Kroner, W. Schneid, N. Wiberg, B. Wrackmeyer and G. Ziegleder, J.
1
3
-
NH), 2.43 (s, 9H, -CH
3
), 2.18 (s, 9H, -CH ). C NMR (125.7 MHz, d -
3
8
◦
119
thf, +25 C), d/ppm = 138–125 (Ar), 37.46 (–NCH
3
), 20.75 (–CH
3
); Sn
◦
NMR (186.5 MHz, d/ppm, d
-
4
8
-thf, +25 C, rel. to SnMe
4
in d -benzene):
6
370.48 (s). Elemental analysis, cald. for 3 C 44.6; H 5.1; N 4.2, Found C
4.2; H 5.2; N 4.5. Negative ion MS, m/z 290.9375 (cald. 290.9383) [M]
Chem. Soc., Faraday Trans. 2, 1978, 74, 1909.
2-
II
12 It has been shown previously that the stability of Sn amides to
disproportionation can be strongly influenced by the streric character
of the amide groups, see for example: M. Weidenbruch, K. Sch a¨ fers,
K. Peters and H. G. von Schnering, J. Organomet. Chem., 1990, 381,
173.
correct isotope pattern.
¶
Crystal data for 2. MeCN·C24
31 3 6
H N S Sn, M = 672.57, monoclinic, space
group P21/c, Z = 4, a = 7.7617(1), b = 13.0775(2), c = 28.9361(6) A˚ ,
◦
3
-1
b = 97.770(1) , V = 2910.15(8) A˚ , m(Mo-Ka) = 1.389 mm , rcalc
1
0
=
=
-3
.535 Mg m , T = 180(2) K. Total reflections 9164, unique 2909 (Rint
13 R. J. Less, V. Naseri, M. McPartlin, D. S. Wright, unpublished results.
14 A. ur Rehman, S. Ali, G. Kociok-K o¨ hn and K. C. Molloy, J. Mol.
Struct., 2009, 56, 937.
.020). R1 = 0.030 [I>2s(I)] and wR2 = 0.087 (all data). Crystal data
for 3. C25
34 2 6
H N S Sn, M = 673.59, monoclinic space group P21/c, Z = 4,
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