Angewandte
Chemie
oborate ([Ph3C]BF4; 410 mg, 1.24 mmol) to the solution of 2a or 2b at
ꢀ808C, an immediate color change from orange to red to dark
Bordeaux red/violet was observed. The reaction mixtures were
allowed to stir while gently warming to ambient temperature to
yield a light red (for 5) or dark purple solution (for 6). After
evaporation and low-temperature column chromatography (5:
ꢀ208C; Al2O3 using the following eluents: 1) petroleum ether,
2) petroleum ether/diethyl ether 95:5, and 3) 90:10; 6: ꢀ208C; SiO2
using pure petroleum ether), complexes 5 and 6 were obtained as
solids after removal of solvent in vacuo.
Received: May 12, 2010
Published online: August 16, 2010
Keywords: EPR spectroscopy · phosphanyl complexes ·
.
phosphaquinomethane · phosphinidenoid complexes ·
tritylium salts
5: Pale yellow solid; yield: 440 mg (0.57 mmol, 57%); m.p. 1588C
(decomp.); selected NMR data: 13C{1H} NMR: d = 10.7 (d, JP, C = 1.9
Cp*-CH3), 10.8 (d, JP, C = 1.6 Hz, Cp*-CH3), 11.3 (d, JP, C = 0.8 Hz, Cp*-
[1] Reviews: a) V. Ya Lee, M. Nakamoto, A. Sekiguchi, Chem. Lett.
2008, 37, 128; b) J. Iley in The Chemistry of Organic Germanium,
Tin and Lead Compounds (Eds.: S. Patai, Z. Rappoport), Wiley,
[2] Recent examples of Group 14 element radicals: a) C. Drost, J.
1965; b) C. Fꢂrster, K. W. Klinkhammer, B. Tumanskii, H.-J.
[3] S. Marque, P. Tordo, Top. Curr. Chem. 2005, 250, 43 – 76.
[4] M. J. S. Gynane, A. Hudson, M. F. Lappert, P. P. Power, H.
[5] S. L. Hinchley, C. A. Morrison, D. W. H. Rankin, C. L. B.
Macdonald, R. J. Wiacek, A. H. Cowley, M. F. Lappert, G.
CH3), 12.2 (d,
J
P, C = 1.6 Hz, Cp*-CH3), 12.9 (d, 3JP, C = 5.0 Hz,
1
Cp*(C1)-CH3), 55.5 (d, 5JP, C = 1.4 Hz, CHArPh2), 63.6 (d, JP, C
=
2.3 Hz, Cp*(C1)), 125.6 (s, p-Ph), 127.4 (d, JP, C = 14.7 Hz, Ar), 127.5
(s, o-Ph), 128.4 (s, m-Ph), 132.4 (d, JP, C = 15.8 Hz, Ar), 132.7 (d, 1JP, C
=
18.5 Hz, i-Ar), 133.0 (d, JP, C = 6.5 Hz, Cp*), 138.7 (d, JP, C = 4.3 Hz,
Cp*), 141.2 (d, JP, C = 6.8 Hz, Cp*), 142.0 (d, JP, C = 3.6 Hz, i-Ph), 143.7
(d, JP, C = 8.7 Hz, Cp*), 146.9 (d, 4JP, C = 2.6 Hz, p-Ar-CHPh2), 195.2
2
(dsat
,
2JP, C = 7.1 Hz, 1JW,C = 126.7 Hz, cis-CO), 196.8 ppm (d, JP, C
=
32.9 Hz, trans-CO); 31P{1H} NMR: d = 114.5 ppm (ssat
,
1JW,P
=
279.7 Hz); MS: m/z (%): 768 (1) [M+]; IR (KBr; n(CO)): n˜ = 1931
(s), 1988 (m), 2073 (m) cmꢀ1. Elemental analysis (%) calcd for
C34H30ClPO5W: C 53.11, H 3.93; found: C 52.95, H 3.81.
6: purple, air-sensitive solid; yield: 475 mg (0.63 mmol, 63%);
m.p. 1698C (decomp.); selected NMR data: 13C{1H} NMR: d = 2.3 (d,
3JP, C = 2.6 Hz, SiMe3), 34.7 (dd, 1JP, C = 13.9 Hz, PCH), 124.3 (d, 2JP, C
=
34.9, CH), 126.2 (d, 3JP, C = 42.1 Hz, CH), 127.5 (m, Ph/CH), 128.0 (m,
4
Ph/CH), 130.0 (s, Ph), 131.4 (s, Ph), 131.5 (s, Ph), 134.2 (d, JP, C
=
5
=
=
32.5 Hz, C C-Ph2), 141.7 (s, i-Ph), 142.6 (d, JP, C = 8.9 Hz, C CPh2),
142.7 (s, i-Ph), 163.9 (d, 1JP, C = 48.5 Hz, P C), 196.2 (dsat
,
1JW,C
=
[6] A. H. Cowley, R. A. Kemp, J. C. Wilburn, J. Am. Chem. Soc.
1982, 104, 332 – 334.
=
125.5 Hz, 2JP, C = 13.2 Hz, cis-CO), 200.3 ppm (d, 2JP, C = 30.0 Hz,
trans-CO); 31P{1H} NMR: d = 189.6 ppm (ssat, JW,P = 269.5 Hz); MS:
1
[7] a) M. J. S. Gynane, A. Hudson, M. F. Lappert, P. P. Power, H.
Bezombes, K. B. Borisenko, P. B. Hitchcock, M. F. Lappert, J. E.
[8] S. Loss, A. Magistrato, L. Cataldo, S. Hoffmann, M. Geoffroy, U.
Rꢂthlisberger, H. Grꢁtzmacher. Angew. Chem. 2001, 113, 749–
Int. Ed. 2001, 40, 723 – 726.
m/z (%): 756 (28) [M+]; IR (nujol; n(CO)): n˜ = 1941 (s), 1981 (m),
2068 (m) cmꢀ1; elemental analysis (%) calcd for C31H33PO5Si2W:
C 49.21, H 4.40; found: C 48.95, H 4.21.
For X-ray analysis data of complexes 5 and 6 and the synthesis of
complexes 8 and 9, see the Supporting Information.
Analysis of experimental hyperfine coupling constants: The
anisotropic hyperfine coupling constants give direct information
about the amount of 31P(3p) character of the singly occupied
molecular orbital. The constants adip,? and adip,k are related to the 3p
spin density at 31P according to reference [25] [Eq. (1) and (2)]:
[9] B. Cetinkaya, A. Hudson, M. F. Lappert, H. Goldwhite, J. Chem.
Soc. Chem. Commun. 1982, 609 – 610.
[10] Reduction of dihalo(organo)phosphanes might yield P-func-
tionalized phosphanyl radicals as transient species, but only
subsequently formed products have been unambigously identi-
fied to date; see for example: J. Geier, H. Rꢁegger, M. Wꢂrle, H.
[12] A. ꢃzbolat, G. von Frantzius, J. Marinas-Perez, M. Nieger, R.
[13] A. ꢃzbolat, G. von Frantzius, W. Hoffbauer, R. Streubel, Dalton
31
adip,k ¼ 4=5ð917 MHzÞ 1ð Pð3pÞÞ
ð1Þ
ð2Þ
31
adip,? ¼ ꢀ2=5ð917 MHzÞ 1ð Pð3pÞÞ
The isotropic hyperfine interaction aiso(31P), visible in the ESR
spectra of the liquid solution, derives from two origins. First, owing to
spin polarization mechanisms, the 31P(3p) spin population also causes
the presence of a small amount of 31P(3s) spin population. The
amount of 31P(3s) spin population by polarization is estimated by a
McConnell-like relation using a value of 1.13% spin polarization
[Eq. (3)]:[25]
31
31
[14] M. Bode, J. Daniels, R. Streubel, Organometallics 2009, 28,
4636 – 4638.
1polð Pð3pÞÞ ꢁ 0:0113 1ð Pð3pÞÞ
ð3Þ
[15] R. Streubel, A. ꢃzbolat-Schꢂn, M. Bode, J. Daniels, G.
Schnakenburg, F. Teixidor, C. Vinas, A. Vaca, A. Pepiol, P.
[16] C. Albrecht, M. Bode, J. M. Pꢄrez, G. Schnakenburg, R.
Streubel, unpublished results.
Further 3s spin density may be introduced if the local environ-
ment of phosphorus is not planar. In this case, the sp2 hybridization
scheme is no longer valid and a direct contribution of the 3s orbital in
the wavefunction of the unpaired electron is expected. The total spin
population in the 3s orbital gives rise to an isotropic hyperfine
coupling constant [Eq. (4)]:
[18] R. Streubel, U. Rhode, J. Jeske, F. Ruthe, P. G. Jones, Eur. J.
31PÞ ¼ ð13 306 MHzÞ 1tot
ð
31Pð3sÞÞ
ð4Þ
aiso
ð
Angew. Chem. Int. Ed. 2010, 49, 6894 –6898
ꢀ 2010 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim