From a phosphagermaallene -P=C=Ge< and heavier chalcogens (S, Se, Te): Access to 3-phosphanylidene-l,2-chalcogenagermiranes

Article abstract of DOI:10.1021/om801133h

Chalcogenagermiranes that feature an exocyclic P=C double bond were obtained from the phosphagermaallene Mes*P= C=Ge(t-Bu)Tip (Mes* = 2,4,6-tritert-butylphenyl, Tip = 2,4,6-triisopropylphenyl) and heavier chalcogens. The structural data of selena- and telluragermiranes show they are intermediate between a normal three-membered ring and a π-complex.

Full text of DOI:10.1021/om801133h

Organometallics 2009, 28, 1973–1975
1973
From a Phosphagermaallene -PdCdGe< and Heavier Chalcogens
(S, Se, Te): Access to 3-Phosphanylidene-1,2-Chalcogenagermiranes
Fatima Ouhsaine,†,‡ Henri Ranaivonjatovo,‡ Jean Escudie´,*,‡ Nathalie Saffon,§ and
Mohamed Lazraq†
Laboratoire d’Inge´nierie des Mate´riaux Organome´talliques et Mole´culaires, UniVersite´ Sidi Mohamed Ben
Abdellah, Faculte´ des Sciences Dhar El Mehraz, BP 1796, Fe`s, Morocco, UniVersite´ de Toulouse, UPS,
LHFA, 118 route de Narbonne, F-31062, Toulouse, France; CNRS, LHFA UMR 5069, F-31062, Toulouse,
France, and Structure Fe´de´ratiVe Toulousaine en Chimie Mole´culaire (FR2599), UniVersite´ Paul Sabatier,
118 route de Narbonne, 31062 Toulouse Cedex 9, France
ReceiVed NoVember 26, 2008
Scheme 1
Summary: Chalcogenagermiranes that feature an exocyclic PdC
double bond were obtained from the phosphagermaallene Mes*Pd
CdGe(t-Bu)Tip (Mes* ) 2,4,6-tritert-butylphenyl, Tip ) 2,4,6-
triisopropylphenyl) and heaVier chalcogens. The structural data
of selena- and telluragermiranes show they are intermediate
between a normal three-membered ring and a π-complex.
Allenes play important role in organic chemistry. Their
heavier congeners EdCdE′ (E, E′ ) Si, Ge, Sn, N, P, As, O,
S) have attracted considerable interest in recent years.1 Indeed,
such heavier heteroallenes appear to be valuable building blocks
owing to the diversified reactivity of two double bonds.
Whereas many heteroallenes -PdCdE (E ) C, N, P, As,
O, S)1 have been prepared, only a few stable heavier group 14
element-containing representatives of general formula
>E14dCdE (E14 ) Si, E ) C,2,3 E ) N;4 E14 ) Ge, E ) C;5
E14 ) Sn, E ) N6) have been described, and their reactivity is
still poorly documented. However, for E ) N, the corresponding
derivatives display important zwitterionic or silylene (or stan-
nylene)-isocyanide contributions.
aallene Mes*PdCdSi(Ph)Tip (Mes* ) 2,4,6-tritert-butylphenyl,
Tip ) 2,4,6-triisopropylphenyl)7a and the transient phosphager-
maallene Mes*PdCdGeMes2 (Mes ) 2,4,6-trimethylphenyl)7b
have been characterized only at low temperature by spectro-
scopic techniques as well as by trapping reactions. Attaching
very bulky groups to both the germanium and the phosphorus
atoms successfully led to the first stable 1,3-phosphagermaallene
Mes*PdCdGe(t-Bu)Tip 1.7c
The steric protection in phosphagermaallene 1 seems par-
ticularly convenient for an efficient kinetic stabilization of
strained Se- or Te-containing small ring compounds which are
known to be generally labile.
In the field of heteroallenes comprising two heavier elements
of group 14 and 15 -E15dCdE14<, the transient phosphasil-
Here we report on a thiagermirane and on its selenium and
tellurium analogues, that feature an exocyclic PdC double bond.
They were obtained from the phosphagermaallene Mes*PdCd
Ge(t-Bu)Tip 1 and heavier chalcogens.
* To whom correspondence should be addressed. E-mail: escudie@
chimie.ups-tlse.fr.
† Universite´ Sidi Mohamed Ben Abdellah.
‡ Universite´ de Toulouse.
§ Universite´ Paul Sabatier.
Results and Discussion
(1) For reviews on heteroallenes, see: (a) Escudie´, J.; Ranaivonjatovo,
H.; Rigon, L. Chem. ReV. 2000, 100, 3639. (b) Eichler, B.; West, R. AdV.
Organomet. Chem. 2001, 46, 1. (c) Yoshifuji, M.; Toyota, K. In The
Chemistry of Organosilicon Compounds; Rappoport, Z., Apeloig, Y., Eds.;
John Wiley and Sons: Chichester, UK, 2001; Vol. 3, p 491. (d) Escudie´, J.;
Ranaivonjatovo, H.; Bouslikhane, M.; El Harouch, Y.; Baiget, L.; Cretiu
Nemes, G. Russ. Chem. Bull. 2004, 53, 1020. (e) Appel, R. Multiple Bonds
and Low Coordination in Phosphorus Chemistry; Georg Thieme, Verlag:
Stuttgart, 1990, p 157. (f) Escudie´, J.; Ranaivonjatovo, H. Organometallics
2007, 26, 1542.
(2) (a) Miracle, G.; Ball, J. L.; Powell, D. R.; West, R. J. Am. Chem.
Soc. 1993, 115, 11598. (b) Trommer, M.; Miracle, G. E.; Eichler, B. E.;
Powell, D. R.; West, R. Organometallics 1997, 16, 5737. (c) Eichler, B. E.;
Miracle, G. E.; Powell, D. R.; West, R. Main Group Met. Chem. 1999, 22,
147. (d) Ichinohe, M.; Tanaka, T.; Sekiguchi, A. Chem. Lett. 2001, 1074.
(3) Transient >SidCdC< have been reported; see: (a) Kunai, A.; Matsuo,
Y.; Ohshita, J.; Ishikawa, M.; Aso, Y.; Otsubo, T.; Ogura, F. Organometallics
1995, 14, 1204, and references therein. (b) Kerst, C.; Ruffolo, R.; Leigh,
W. J. Organometallics 1997, 16, 5804. (c) Kerst, C.; Rogers, C. W.; Ruffolo,
R.; Leigh, W. J. J. Am. Chem. Soc. 1997, 119, 466.
(4) (a) Takeda, N.; Suzuki, H.; Tokitoh, N.; Okazaki, R.; Nagase, S.
J. Am. Chem. Soc. 1997, 119, 1456. (b) Abe, T.; Iwamoto, T.; Kabuto, C.;
Kira, M. J. Am. Chem. Soc. 2006, 128, 4228.
(5) (a) Eichler, B. E.; Powell, D. R.; West, R. Organometallics 1998, 17,
2147. (b) Eichler, B. E.; Powell, D. R.; West, R. Organometallics 1999, 18,
540. (c) Transient germaallene Tbt(Mes)GedCdCR2 has been postulated
as intermediate: Kishikawa, K.; Tokitoh, N.; Okazaki, R. Organometallics
1997, 16, 5127. (d) Tokitoh, N.; Kishikawa, K.; Okazaki, R. Chem. Lett. 1998,
811.
Treatment of phosphagermaallene 1 with elemental sulfur,
selenium, or tellurium in Et2O at -50 °C gave in a good yield the
unprecedented corresponding phosphanylidene-chalcogenager-
miranes 2-4 that exhibit an exocyclic CdP double bond (Scheme
1).
Their structures were determined by 1H, 13C, 31P, 77Se, and 125Te
NMR spectroscopies (2: δ31P ) 252.2 ppm; 3: δ31P ) 278.8 ppm,
(2+3)
(2+3)
J
PSe
) 107.5 Hz; 4: δ31P ) 311.8 ppm,
J
PTe
) 249.6 Hz)
and by mass spectrometry. These large PSe and PTe coupling
(6) Gru¨tzmacher, H.; Freitag, S.; Herbst-Irmer, R.; Sheldrick, G. S.
Angew. Chem., Int. Ed. Engl. 1992, 31, 437.
(7) (a) Rigon, L.; Ranaivonjatovo, H.; Escudie´, J.; Dubourg, A.;
Declercq, J.-P. Chem. Eur. J. 1999, 5, 774. (b) Ramdane, H.; Ranaivon-
jatovo, H.; Escudie´, J.; Mathieu, S.; Knouzi, N. Organometallics 1996, 15,
3070. (c) El Harouch, Y.; Gornitzka, H.; Ranaivonjatovo, H.; Escudie´, J.
J. Organomet. Chem. 2002, 643-644, 202.
(8) (a) Asmus, S. M. F.; Bergstra¨sser, U.; Regitz, M. Synthesis 1999,
1642. (b) Asmus, S. M. F.; Seeber, G.; Bergstra¨sser, U.; Regitz, M.
Heteroatom. Chem. 2001, 12, 406. (c) Francis, M. D.; Jones, C.; Morley,
C. P. Tetrahedron Lett. 1999, 40, 3815. (d) Francis, M. D.; Hibbs, D. E.;
Hitchcock, P. B.; Hursthouse, M. B.; Jones, C.; Mackewitz, T.; Nixon, J. F.;
Nyulaszi, L.; Regitz, M.; Sakarya, N. J. Organomet. Chem. 1999, 580, 156.
(e) Francis, M. D.; Jones, C.; Junk, P. C.; Roberts, J. L. Phosphorus, Sulfur
Silicon 1997, 23, 130.
10.1021/om801133h CCC: $40.75
2009 American Chemical Society
Publication on Web 02/23/2009

1974 Organometallics, Vol. 28, No. 6, 2009
Notes
cyclic CdC double bond have been prepared from sulfur or
selenium and the germaallene Tbt(Mes)GedCdCR2 (CR2
)
fluorenylidene, Tbt ) 2,4,6-[(Me3Si)2CH]3C6H2).5c All other thi-
agermiranes have been obtained by reaction between a germylene
and thioketones.9
The Ge1-Se1 (2.3837(6) Å), C1-Se1 (1.951(4) Å), Ge1-Te1
(2.5887(9) Å), and C1-Te1 (2.122(6) Å) bond lengths in 3 and
4 are similar to those reported in a triselenagermole, (dGeSe )
2.402(1) Å) and (dCSe ) 1.984(4) Å),10 and in a tellurager-
mirane, (dGeTe ) 2.591(3) Å) and (dCTe ) 2.11(2) Å).5c The
exocyclic Ge-C bonds lengths for Ge-t-Bu and Ge-Tip
(1.957(6) to 2.001(4) Å) lie in the normal range.11 In contrast,
the intracyclic Ge1-C1 bond length is slightly shortened in 3
(1.944(4) Å) and even more in 4 (1.912(6) Å) with large
P1C1Ge1 bond angles in 3 (164.0(2)°) and in 4 (144.3(4)°).
Moreover, the sum of the bond angles around the germanium
atom (C1-Ge1-C6, C2-Ge1-C6 and C1-Ge1-C2) ignoring
selenium (358.6° in 3) or tellurium (353.5° in 4) is close to
360°, showing that the germanium center displays some sp2
character. We can assume that this partially planar geometry
corresponds to a structure intermediate between a normal three-
membered ring and a π-complex.
Figure 1. Molecular structure of 3. Thermal ellipsoids are drawn at
50% probability level. Hydrogen atoms are omitted for clarity. Selected
bond lengths (Å) and angles (deg): Ge1-C1 ) 1.944(4); Ge1-C6 )
1.968(4); Ge1-C2 ) 2.001(4); Ge1-Se1 ) 2.3837(6); P1-C1 )
1.659(4); P1-C21 ) 1.865(4); Se1-C1 ) 1.951(4); C1-Ge1-C6
)118.78(16);C1-Ge1-C2)120.74(17);C6-Ge1-C2)119.09(17);
C1-Ge1-Se1)52.41(11);C6-Ge1-Se1)115.75(12);C2-Ge1-Se1
) 109.52(13); C1-P1-C21 ) 107.26(18); C1-Se1-Ge1 ) 52.12(11);
P1-C1-Ge1 ) 164.0(2); P1-C1-Se1 ) 120.2(2); Ge1-C1-Se1
) 75.47(14).
Similar planar structures were found in other three-membered
heterocycles containing one germanium atom such as GePS12a and
GeCTe5c or two germanium atoms like GeGeX (X ) C,12b N,12b
S,12c Te,12d). These results can be interpreted in terms of Dewar-
Chatt-Duncanson model of metal olefin bonding.
In conclusion, although 1 possesses two reactive double
bonds, addition of chalcogens happened to take place selectively
on the GedC unsaturation. This illustrates the synthetic potential
of this heteroallene in organometallic and heterocyclic chemistry
since the PdC unsaturation and the phosphorus lone pair remain
available for a further reaction.
Experimental Section
All experiments were carried out in flame-dried glassware under a
nitrogen atmosphere using high-vacuum-line techniques. Solvents were
dried and freshly distilled from sodium benzophenone and carefully
deoxygenated on the vacuum line by several “freeze-pump-thaw”
cycles. NMR spectra were recorded in CDCl3 on a Bruker Avance
300 spectrometer at the following frequencies: 1H, 300.13 MHz; 13C,
75.47 MHz (reference TMS); 31P, 121.51 MHz (reference H3PO4);
on a Bruker Avance 400 spectrometer for 77Se, 76.31 MHz (reference
Me2Se) and on a Bruker Avance 500 spectrometer for 125Te, 175.85
MHz (reference Me2Te). Mass spectra were obtained on a Hewlett-
Packard 5989A spectrometer by EI at 70 eV and on a Nermag R10-10
spectrometer by CI. Melting points were determined on a Wild Leitz-
Biomed apparatus. Elemental analyses were performed by the Service
de Microanalyse de l’Ecole de Chimie de Toulouse.
Figure 2. Molecular structure of 4. Thermal ellipsoids are drawn at
50% probability level. Hydrogen atoms are omitted for clarity. Selected
bond lengths (Å) and angles (deg): Ge1-C1 ) 1.912(6); Ge1-Te1
) 2.5887(9); C1-Te1 ) 2.122(6); C1-P1 ) 1.666(7); Ge1-C6 )
1.957(6); Ge1-C2 ) 1.969(8); P1-C21 ) 1.856(6); Ge1-C1-Te1
) 79.6(2); Ge1-Te1-C1 ) 46.60(17); C1-Ge1-Te1 ) 53.76(19);
C1-Ge1-C6 ) 119.6(3); C6-Ge1-C2 ) 117.7(3); C1-Ge1-C2
) 116.2(3); P1-C1-Te1 ) 136.1(4); P1-C1-Ge1 ) 144.3(4).
constants are greater than those found for selenadiphospholes
(50-80 Hz)8a-d and telluradiphospholes (130-150 Hz).8c,d A 2JPSe
coupling constant of 98 Hz was reported in an acyclic PdC-Se
unit.8e
The structures of the three-membered heterocycles 3 (Figure 1)
and 4 (Figure 2) were confirmed by an X-ray analysis. Compound
4 adopts the Z configuration around the PdC double bond with
the huge Mes* group in the cis disposition to the chalcogen atom
whereas a trans disposition was observed for derivative 3 (Scheme
1). The origin for this surprising opposite arrangement is not clear
at the moment.
Compound 4 is the first telluragermirane to be synthesized by a
direct reaction between a germanium-carbon doubly bonded
compound and elemental tellurium (a telluragermirane has been
obtained by reaction between a germaallene and R3PdTe5c)
whereas a thiagermirane and a selenagermirane bearing an exo-
3-(2,4,6-Triisopropylphenyl)-3-tert-butyl-1-(2,4,6-tritert-bu-
tylphenyl)phosphagermaallene 1. Phosphagermaallene 1 was
synthesized as previously described7c by addition of a solution of tert-
butyllithium 1.6 M in pentane (1.1 mL) to a solution of fluorophos-
phagermapropene Mes*PdC(Cl)-Ge(t-Bu)(F)Tip (1.04 g, 1.54 mmol)
in Et2O (20 mL) cooled to -78 °C. A 31P NMR analysis (δ 249.9
(9) (a) Tsumuraya, T.; Sato, S.; Ando, W. Organometallics 1989, 8,
161. (b) Ando, W.; Tsumuraya, T. Tetrahedron Lett. 1986, 27, 3251. (c)
Ando, W.; Tsumuraya, T. Organometallics 1989, 8, 1467.
(10) Nakata, N.; Takeda, N.; Tokitoh, N. Chem. Lett. 2002, 818.
(11) (a) Baines, K. M.; Stibbs, W. G. Coord. Chem. ReV. 1995, 145, 157.
(b) Holloway, C. E.; Melnik, M. Main Group Met. Chem. 2002, 25, 185.
(12) (a) Andrianarison, M.; Couret, C.; Declercq, J.-P.; Dubourg, A.;
Escudie´, J.; Ranaivonjatovo, H.; Satge´, J. Organometallics 1988, 7, 1545.
(b) Tsumuraya, T.; Sato, S.; Ando, W. Organometallics 1990, 9, 2061. (c)
Tsumuraya, T.; Sato, S.; Ando, W. Organometallics 1988, 7, 2015. (d)
Tsumuraya, T.; Kabe, Y.; Ando, W. J. Chem. Soc. Chem. Commun. 1990, 1159.

Notes
Organometallics, Vol. 28, No. 6, 2009 1975
Table 1. Crystal Data and Structure Refinement for 3 and 4
1.20 (s, 9H, o-t-Bu of Mes*); 1.24 (s, 9H, t-BuGe or p-t-Bu of Mes*);
1.54 (s, 9H, o-t-Bu of Mes*); 2.36 (broad s, ∆ν1/2 ) 23.8 Hz, 1H,
o-CHMeMe′ of Tip); 2.73 (sept, JHH ) 6.9 Hz, 1H, p-CHMeMe′ of
Tip); 3.69 (broad s, ∆ν1/2 ) 25.6 Hz, 1H, o-CHMeMe′ of Tip); 6.74
and 6.88 (2 broad s, ∆ν1/2 ) 20 Hz, 2 × 1H, arom H of Tip); 7.24
and 7.36 (2s, 2 × 1H, arom H of Mes*).
3
4
Empirical formula
Formula weight
Crystal system
Space group
a (Å)
C38H61GePSe
700.39
C38H61GePTe
749.03
Triclinic
Monoclinic
P21/n
j
P1
9.5103(2)
11.9174(2)
17.9636(4)
83.2120(10)
79.6660(10)
74.8620(10)
1927.97(7)
2
10.0341(3)
22.9800(8)
17.4571(6)
90.00
13C NMR. δ 23.81; 23.91; 24.19; 34.19 and 34.30 (o-CMe3 of
Mes*, CH and Me of iPr; some signals are too broad to be observed);
28.98 and 31.41 (GeCMe3 and p-CMe3); 33.45 (d, JCP ) 8.6 Hz,
o-CMe3 of Mes*); 33.86 (d, JCP ) 4.7 Hz, o-CMe3 of Mes*); 35.09;
38.07; 38.86 (CMe3 of t-Bu); 122.00 and 122.10 (arom CH of Mes*);
b (Å)
c (Å)
R (deg)
ꢀ (deg)
103.726(3)
90.00
γ (deg)
V (Å3)
3910.4(2)
4
122.30 (arom CH of Tip); 128.04 (ipso-C of Tip); 142.01 (d, 1JPC
)
Z
Density (calculated) (g/cm3)
Absorption coefficient µ (mm-1
F(000)
1.206
1.272
73.8 Hz, ipso-C of Mes*); 148.69; 149.73; 151.14 and 153.09 (arom
)
1.802
1.578
C of Tip and Mes*); 153.22 (d, 2JPC ) 6.1 Hz o-C of Mes*); 174.57
740
1552
(d, 1JPC ) 87.7 Hz, CdP).
Crystal size (mm)
Temperature (°C)
Scan mode
0.15 × 0.10 × 0.10 0.1 × 0.1 × 0.08
-80
-80
(2+3)
31P NMR. δ 278.8 (
J
PSe
(2+3)
) 107.5 Hz).
PSe
ω, φ
ω, φ
77Se NMR. δ 103.7 (d,
J
) 107.5 Hz).
Detector
Bruker APEX II
24.71
Bruker APEX II
24.71
MS (EI, 70 eV, m/z, %). 700 (M+, 10); 643 (M+ - t-Bu, 20);
275 (Mes*P - 1, 30); 57 (t-Bu, 100).
θmax (deg)
no. obsd reflns
Rmerge
24119
0.0683
30121
0.1622
Anal Calcd for C38H61GePSe: C, 65.16; H, 8.78. Found: C,
65.42; H, 8.80.
Data/restraints/parameters
R indices [I > 2s(I)]
6497/78/414
wR2 ) 0.0955
R1 ) 0.0443
wR2 ) 0.1089
R1 ) 0.0794
1.019, -0.355
6595/21/405
wR2 ) 0.0935
R1 ) 0.0514
wR2 ) 0.1223
R1 ) 0.1396
0.561, -0.795
4: orange crystals, 0.76 g (69%), mp: 180 °C.
1H NMR. δ 1.04 (d, JHH ) 6.5 Hz, 3H, o-CHMeMe′ of Tip); 1.20
(d, JHH ) 6.9 Hz, 6H, p-CHMeMe’ of Tip); 1.23 (s, 9H, t-BuGe or
R indices (all data)
max. diff peak, hole (e/Å3)
3
p-t-Bu of Mes*); 1.25 (d, JHH ) 6.7 Hz, 3H, o-CHMeMe′ of Tip);
ppm) showed the nearly quantitative formation of phosphagermaallene
1. Solutions of 1 were used directly without further purification.
General Procedure for the Reaction of 1 with Chalcogens.
A crude solution of 1 prepared as previously described was cooled to
-50 °C and was canulated into a flask, maintained at -50 °C,
containing one equivalent of the heavier chalcogen. The reaction
mixture rapidly turned brown (with sulfur), yellow-green (with
selenium), or red (with tellurium) on warming to room temperature.
After stirring overnight, it was black in all cases. The solvents were
removed under vacuum and replaced by 20 mL of pentane. LiF was
filtered out. Crystallization at -30 °C from pentane afforded crystals
of 2, 3, or 4.
1.28 (s, 9H, o-t-Bu of Mes*); 1.32 (s, 9H, t-BuGe or p-t-Bu of Mes*);
1.34 (d, 3JHH ) 6.5 Hz, 3H, o-CHMeMe′ of Tip); 1.38 (d, 3JHH ) 6.5
Hz, 3H, o-CHMeMe′ of Tip); 1.48 (s, 9H, o-t-Bu of Mes*); 2.86 (sept,
3JHH ) 6.9 Hz, 1H, CHMeMe′ of Tip), 3.49 (sept, 3JHH ) 6.6 Hz, 1H,
CHMeMe′ of Tip) and 3.74 (sept, 3JHH ) 6.6 Hz, 1H, CHMeMe′ of
Tip); 6.93 and 6.95 (AB type spectrum, JHAHB ) 1.6 Hz, 2 × 1H,
arom H of Tip); 7.32 and 7.37 (2 broad s, ∆ν1/2 ) 4.0 Ηz, 2 × 1H,
arom H of Mes*).
13C NMR. δ 23.83; 23.94; 24.00; 24.18; 25.21; 25.90; 26.15; 34.19
and 38.53 (CMe3, CH and Me of iPr); 29.80 and 31.40 (GeCMe3 and
p-CMe3); 32.64 (d, JCP ) 7 Hz, o-CMe3 of Mes*); 33.35 (d, JCP ) 7.1
Hz, o-CMe3 of Mes*); 35.03 and 37.94 (CMe3 of t-Bu); 121.40;
122.07; 122.36; 122.72 (arom CH of Mes* and Tip); 129.60 (ipso-C
of Tip); 148.88; 150.88; 151.52; 151.75; 153.28; 154.48 (arom C of
2: white crystals, 0.85 g (89%), mp: 190 °C.
1H NMR. δ 0.23 (broad s, ∆ν1/2 ) 15 Hz, 3H, o-CHMeMe′ of
3
Mes* and Tip); 155.46 (d, 1JCP ) 89 Hz, C)P).
Tip); 0.94-1.15 (m, 9H, o-CHMeMe′ of Tip); 1.11 (d, JHH ) 6.9
(2+3)
31P NMR. δ 311.8. (
J
PTe
(2+3)
) 249.6 Hz).
PTe
Hz, 6H, p-CHMeMe′ of Tip); 1.16 (s, 9H, o-t-Bu of Mes*); 1.17 and
1.25 (2s, 2 × 9H, t-BuGe and p-t-Bu of Mes*); 1.54 (s, 9H, o-t-Bu of
Mes*); 2.32 (broad s, ∆ν1/2 ) 22.4 Hz, 1H, o-CHMeMe′ of Tip); 2.73
(sept, 3JHH ) 6.9 Hz, 1H, p-CHMeMe′ of Tip); 3.48 (broad s, ∆ν1/2
) 22.5 Hz, 1H, o-CHMeMe′ of Tip); 6.71 and 6.88 (2 broad s, ∆ν1/2
) 10.3 Ηz, 2 × 1H, arom H of Tip); 7.24 and 7.36 (2 broad s,
∆ν1/2 ) 5.0 Ηz, 2 × 1H, arom H of Mes*).
125Te NMR. δ -10.9 (d,
J
) 249.6 Hz).
MS (EI, 70 eV, m/z, %). 750 (M+, 3); 691 (M+ - t-Bu - 2,
20); 635 (M+ - 2 t-Bu - 1, 1); 563 (M+ - Te – t-Bu - 2, 2); 333
(Tip(t-Bu)Ge - 1, 10); 275 (Mes*P - 1, 15); 57 (t-Bu, 100).
Anal. Calcd for C38H61GePTe: C, 60.93; H, 8.21. Found: C,
61.05; H, 8.41.
13C NMR. δ 23.25 (broad s); 23.86; 23.95; 24.27 (broad s); 25.72
(broad s); 26.29 (broad s); 34.25; 36.46 (broad s) and 40.00 (broad s)
Crystal Data for 3 and 4. All data were collected at low
temperatures using an oil-coated shock-cooled crystal on a Bruker-
AXS APEX II diffractometer with Mo KR radiation (λ ) 0.71073
Å). The structures were solved by direct methods13 and all non
hydrogen atoms were refined anisotropically using the least-squares
method on F2(Table 1).14
i
(o-CMe3 of Mes*, CH and Me of Pr); 28.97 and 31.47 (GeCMe3
and p-CMe3); 33.40 (d, JCP ) 8.4 Hz, o-CMe3 of Mes*); 33.90 (d,
JCP ) 5.2 Hz, o-CMe3 of Mes*); 34.44, 35.09, 38.28, and 38.94
(CMe3 of t-Bu); 120.87 (broad s), 121.85 (broad s), 122.30 and 122.61
(broad s) (arom CH of Mes* and Tip); 128.59 (ipso-C of Tip); 139.55
1
Acknowledgment. We acknowledge the Centre National
de la Recherche Scientifique (contract CNRS/JSPS PRC
450), the Agence Nationale pour la Recherche (contract
ANR-08-BLAN-0115-01), and the PHC Volubilis (MA/05/
123) for financial support.
(d, JCP ) 66.7 Hz, ipso-C of Mes*); 149.55; 151.28; 153.56
(broad s); 153.71, 154.05 (d, JCP ) 5.7 Hz) and 154.76 (broad s) (arom
C of Mes* and Tip); 181.57 (d, 1JCP ) 78.5 Hz, CdP).
31P NMR. δ 252.2.
MS (EI, 70 eV, m/z, %). 654 (M+, 2); 597 (M+ - t-Bu, 75);
539 (M+ - 2 t-Bu - 1, 4); 276 (Mes*P, 15); 57 (t-Bu, 100).
MS (CI, CH4, m/z, %). 683 (M++ 29, 5); 655 (M+ + 1, 75);
597 (M+ - t-Bu, 100).
Supporting Information Available: X-ray crystallographic files
in CIF format for 3 and 4. This material is available free of charge
via the Internet at http://pubs.acs.org.
Anal Calcd for C38H61GePS: C, 69.84; H, 9.41. Found: C,
70.04; H, 9.60.
OM801133H
3: yellow crystals, 0.87 g (81%), mp: 147 °C.
1H NMR. δ 0.17-0.25 (broad s, ∆ν1/2 ) 23 Ηz, 3H, o-CHMeMe′
of Tip); 0.78-1.3 (m, 9H, o-CHMeMe′ of Tip); 1.11 (d, 3JHH ) 6.8
Hz, 6H, p-CHMeMe′ of Tip); 1.19 (s, 9H, t-BuGe or p-t-Bu of Mes*);
(13) SHELXS-97: Sheldrick, G. M. Acta Crystallogr. 1990, A46, 467.
(14) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure
Refinement; University of Go¨ttingen: Go¨ttingen, 1997.