Syntheses, structures and properties of [{HC(CMeNAr)2}Ge(E)X] (Ar = 2,6-iPr2C6H3; e = S, Se; X = F, Cl)

Article abstract of DOI:10.1039/b211617k

For the first time the structurally characterized heavier chalcogen analogues of alkanoyl halides, [{HC(CMeNAr)₂}Ge(S)X] (Ar = 2,6-iPr₂C₆H₃; X = Cl (1), F (2)) and [{HC(CMeNAr)₂}Ge(Se)X] (X = Cl (4), F (5)) have been prepared from the starting material [{HC(CMeNAr)₂}GeCl] (3). The nature of the germanium-chalcogen bond is best described as between the two resonance structures, Ge⁺-E^- ? Ge=E. The investigation of the reactivity of the germanium-halogen bond with RLi reagents (R = Me, nBu) led to the formation of [{HC(CMeNAr)₂}Ge(E)R] (E = S, R = Me (6); E = Se, R = Me (7), nBu (8)). The solid-state structures of 1, 2, 4, 5, 6, and 8 are reported. The Royal Society of Chemistry 2003.

Full text of DOI:10.1039/b211617k

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Syntheses, structures and properties of [{HC(CMeNAr)2}Ge(E)X]
(Ar ؍ 2,6-iPr2C6H3; E ؍ S, Se; X ؍ F, Cl)
Yuqiang Ding, Qingjun Ma, Herbert W. Roesky,* Isabel Usón, Mathias Noltemeyer and
Hans-Georg Schmidt
Institut für Anorganische Chemie der Universität Göttingen, Tammannstrasse 4,
D-37077 Göttingen, Germany. E-mail: hroesky@gwdg.de; Fax: (ϩ49) 551-393373
Received 27th November 2002, Accepted 23rd January 2003
First published as an Advance Article on the web 10th February 2003
For the first time the structurally characterized heavier chalcogen analogues of alkanoyl halides,
[{HC(CMeNAr)2}Ge(S)X] (Ar = 2,6-iPr2C6H3; X = Cl (1), F (2)) and [{HC(CMeNAr)2}Ge(Se)X] (X = Cl (4),
F (5)) have been prepared from the starting material [{HC(CMeNAr)2}GeCl] (3). The nature of the germanium–
chalcogen bond is best described as between the two resonance structures, Geϩ–EϪ ↔ Ge᎐E. The investigation
᎐
of the reactivity of the germanium–halogen bond with RLi reagents (R = Me, nBu) led to the formation of
[{HC(CMeNAr)2}Ge(E)R] (E = S, R = Me (6); E = Se, R = Me (7), nBu (8)). The solid-state structures of
1, 2, 4, 5, 6, and 8 are reported.
Introduction
Species containing multiple bonded heavier main group ele-
ments are important precursors for a variety of new reactions.
Especially compounds with halides, where the halides can easily
be replaced to synthesize a plethora of new compounds, are of
great interest. Over the past few decades, the double bonds
between heavier main group elements had been considered to
be unstable due to their weak π bonds. However, in 1981, com-
pounds with Si᎐C,1 Si᎐Si,2 and P᎐P3 bonds were prepared by
᎐
᎐
᎐
taking advantage of the protection from bulky ligands. After
that, remarkable progress has been made in the chemistry of
multiple bonded compounds of heavier main group elements.
In recent years, the chemistry of formal double bonded species
between Group 14 and 16 elements has received much atten-
Scheme 1
tion, since M᎐E (M = C, Si, Ge, Sn, Pb; E = O, S, Se, Te) is one
᎐
of the most important and fundamental functionalities in main
group chemistry.4
Results and discussion
Theoretical calculations show that in the carbon–oxygen
double bond (ketone), the σ and π bond energies are almost
equal, while in the others (heavier ketone analogues) the σ bond
is much greater in energy than the corresponding π bond.
Therefore, these heavier ketones are more reactive and hence
the formation of one new σ bond on the metal is favorable.5
Although the chemistry of ketones has long been established,
the preparation of heavier congeners of thioketones and
selenoketones appeared in the literature in 1980s and in 1993,
Syntheses and structures of compounds 1 and 4, the heavier
chalcogen analogues of alkanoyl halides
Although chalcogen derivatives of the heavier Group 14
elements are reactive, such species can be stabilized by bulky
ligands and are usually prepared by reaction of the divalent
Group 14 compounds with elemental chalcogens.7–9 The
successful preparation of the structurally characterized ger-
manium() hydride and fluoride [{HC(CMeNAr)2}GeF] (9)12
from a stable germanium() chloride, [{HC(CMeNAr)2}GeCl]
(3)11 prompted us to synthesize [{HC(CMeNAr)2}GeE(X)]
(E = chalcogen, X = halogen). Therefore, compound 3 was
treated with elemental sulfur in toluene at ambient temperature
for 2 days, and after work up, [{HC(CMeNAr)2}Ge(S)Cl] (1)
was obtained in excellent yield (88%) (Scheme 2). With a similar
procedure, however, using dichloromethane as a solvent, the
selenium analogue [{HC(CMeNAr)2}Ge(Se)Cl] (4) was
obtained in 87% yield (Scheme 2).
Compounds 1 and 4 are soluble in toluene, THF, and di-
chloromethane, but only sparingly soluble in hexane and diethyl
ether. They are stable in these solvents or as solids under an
inert atmosphere at room temperature, no decomposition was
observed under such condition for six months. However, they
can be decomposed at temperatures above 225 and 230 ЊC,
respectively.
for telluroketone.6 Moreover, examples of M᎐E (M = Si, Ge, Sn;
᎐
E = S, Sn, Te) were synthesized only after 1989 by taking
advantage of the steric bulk of the ligand.7–9 In contrast, the
chemistry of such compounds bearing halides was neglected.
We were interested in the preparation of the heavier chalcogen
analogues of alkanoyl halide M(Cl)᎐E as potentially important
᎐
precursors for the synthesis of compounds containing formal
double bonded heavier main group elements (Scheme 1).
In a preliminary communication we reported on the synthesis
and structures of [{HC(CMeNAr)2}Ge(S)X] (Ar = 2,6-iPr2-
C6H3; X = Cl (1), F (2))10 as the first structurally characterized
example with a formal double bond between Group 14 and 16
elements bearing a halide by the reaction of [{HC(CMeNAr)2}-
GeCl] (3)11 with elemental sulfur. In this paper we report the
details of the synthesis, structures and some new findings of
their properties, along with the selenium analogue [{HC-
(CMeNAr)2}Ge(Se)X] (X = Cl (4), F (5)), as well as their
dehalogenated derivative [{HC(CMeNAr)2}Ge(E)R] (E = S, Se;
R = Me, nBu (6–8)).
Compounds 1 and 4 were fully characterized by elemental
analyses, EI-MS and multinuclear NMR spectroscopy. In the
1H NMR spectra, the resonances of the methyl groups of the
D a l t o n T r a n s . , 2 0 0 3 , 1 0 9 4 – 1 0 9 8
T h i s j o u r n a l i s © T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 3
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Fig. 1 Molecular structure of 1 in the crystal (50% probability thermal
ellipsoids). Selected bond lengths (Å) and angles (Њ): Ge(1)–Cl(1)
2.195(7), Ge(1)–S(1) 2.053(6), Ge(1)–N(1) 1.881(1), Ge(1)–N(2)
1.910(1); S(1)–Ge(1)–N(1) 118.87(4), S(1)–Ge(1)–N(2) 118.33(4), S(1)–
Ge(1)–Cl(1) 116.82(2), N(1)–Ge(1)–N(2) 98.18(6), Cl(1)–Ge(1)–N(1)
99.51(4), Cl(1)–Ge(1)–N(2) 101.54(5).
Scheme 2
aryl substituents could be distinguished due to their different
environments (see Experimental section). EI-MS of 1 and 4
both gave the corresponding monomeric molecular ion peak
Mϩ. The 77Se NMR spectrum of 4 consists of a singlet
resonance at Ϫ288 ppm. The elemental analyses are also in
accordance with 1 and 4 as formulated.
One of the interests in 1 and 4 is the nature of the ger-
manium–chalcogen bond. The property of the Ge᎐E bond in
Fig. 2 Molecular structure of 4 in the crystal (50% probability thermal
ellipsoids; hydrogen atoms are omitted for clarity). Selected bond
lengths (Å) and angles (Њ): Ge(1)–Cl(1) 2.164(8), Ge(1)–Se(1) 2.197(6),
Ge(1)–N(1) 1.900(2), Ge(1)–N(2) 1.901(2); Se(1)–Ge(1)–N(1)
119.20(6), Se(1)–Ge(1)–N(2) 118.93(6), Se(1)–Ge(1)–Cl(1) 116.99(3),
N(1)–Ge(1)–N(2) 97.73(8), Cl(1)–Ge(1)–N(1) 100.04(7), Cl(1)–Ge(1)–
N(2) 100.09(6).
᎐
Tbt(Tip)Ge᎐E (Tbt = 2,4,6-tris[bis(trimethylsiyl)methyl]phenyl;
᎐
Tip = 2,4,6-triisopropylphenyl; E = S (10), Se (11)) was studied
and showed double bond character.8g The germanium–sulfur
interaction in those compounds stabilized by intramolecular
coordination of a base was described in terms of the resonance
structures (Scheme 3) although no direct evidence was given.8a
In our current work 77Se NMR was applied to obtain more
insight into the bonding properties.
selected bond lengths and bond angles in the legends. Figs. 1
and 2 show that compounds 1 and 4 are monomeric. The
germanium centers adopt four-coordinated geometries and res-
ide in a distorted tetrahedral environment. The geometries are
similar to those compounds containing terminal chalcogenido
germanium units.
Scheme 3
The Ge–S bond length (2.053(6) Å) in 1 which is shorter than
the reported Ge–S single bond length (2.239(1) Å),8f is in
Studies show that the 77Se chemical shift for the Ge–Se single
bond in (H3Ge)2Se is Ϫ612 ppm (relative to Me2Se).13 In con-
agreement with those (2.063(3) Å8a and 2.045(3) Å8g) for Ge᎐S
᎐
which are stabilized by an intramolecular base. The Ge–Se
bond length (2.197(6) Å) in compound 4 is also in the normal
trast, the available data for germanium selenones, R Ge᎐Se,
᎐
2
show resonances at a much lower field (800–1100 ppm).8f–h
Since the observed chemical shift for 4 is Ϫ288 ppm, it appears
as though the value is somewhat between that for a single bond
and those for double bond systems. This finding suggests that
the resonance structure may represent the bonding interaction
in 1 and 4.
range for a Ge᎐Se double bond (2.180(2)–2.247 Å),8f,g and is
᎐
obviously shorter than the Ge–Se single bond in [Tbt(Mes)-
GeSe]2 (Mes = 2,4,6-trimethylphenyl) (2.433(1) Å).8g These
shorter Ge᎐E bond lengths in 1 and 4 are indicative for a formal
᎐
double bond or a Ge–E σ bond with additional significant ionic
character. The Ge–Cl bond lengths in 1 (2.195(7) Å) and in 4
(2.164(8) Å) are shorter compared to those in the starting
material 3 (2.295(1) Å) due to the higher oxidation state of the
metal. It also influences the contact of the germanium atom
with the ligand, and therefore, shorter Ge–N bond lengths
(1.881(1) and 1.910(1) Å in 1, 1.900(2) and 1.901(2) Å in 4) are
In order to obtain more information on the germanium–
chalcogen interaction, pale yellow crystals of 1 and 4 were gen-
erated from toluene and dichloromethane solution, respectively,
at Ϫ32 ЊC and determined by single crystal X-ray diffraction.
The structures of 1 and 4 are shown in Figs. 1 and 2 with
D a l t o n T r a n s . , 2 0 0 3 , 1 0 9 4 – 1 0 9 8
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observed when compared to those in 3 (1.988(2) and 1.997(3)
Å). The N–Ge–N bond angles in 1 (98.18(6)Њ) and in 4
(97.73(8)Њ) are larger than that in 3 (90.89(10)Њ).
respectively) are slightly shorter compared to the corresponding
precursors 1 and 4 (2.053(6) and 2.197(6) Å, respectively) due to
the influence of the fluorine. The Ge–F bond lengths in 2 and 5
(1.848(2) and 1.758(3) Å, respectively) are in the expected range
(1.781(10)14 to 1.867(14) Å15).
Syntheses and structures of compounds 2 and 5, the fluoro
analogues of 1 and 4
Syntheses and structures of compounds 6–8, the dehalogenated
We were interested in the synthesis of fluoro analogues of 1 and
4, which may have different reactivity and structures due to the
stronger electron-withdrawing property of fluorine compared
to the other halogens. Therefore, [{HC(CMeNAr)2}Ge(E)F]
(E = S (2), Se (5)) was generated by two routes: from 1 and 4 by
fluorination with Me3SnF or from 9 by the oxidative addition
of elemental chalcogen (Scheme 2). Both methods yield color-
less crystals from toluene solutions. The 77Se NMR resonance
of 5 at Ϫ464 ppm is closer to the chemical shift of compounds
containing germanium–selenium single bonds. This indicates
the influence of the substituents on the germanium–selenium
bond in 5.
The single crystal X-ray diffraction structures of 2 and 5 were
measured and depicted in Figs. 3 and 4 with selected bond
lengths and bond angles. Both 2 and 5 are isostructural to the
starting materials, with the replacement of chlorine by fluorine.
The Ge–E bond lengths in 2 and 5 (2.050(9) and 2.176(7) Å,
derivatives of 1, 2, 4 and 5
The so far known structurally characterized compounds with
formal double bonded heavier main group elements contain
bulky ligands. The main interest in compounds 1, 2, 4 and 5 is
the halogen–germanium bond which can be utilized in meta-
thesis reactions. One routine reaction of such bonds is the treat-
ment with alkylation reagents. Therefore, compounds 1, 2, 4
and 5 were treated with RLi (R = Me, nBu) at low temperatures.
After work up as described in the Experimental section, crystals
of the alkylated compounds [{HC(CMeNAr)2}Ge(E)R] (E = S,
R = Me (6); E = Se, R = Me (7), nBu (8)) were obtained in
excellent yields (Scheme 2).
Compounds 6–8 were characterized by elemental analysis,
1
EI-MS, H, and 77Se NMR spectroscopy. All the EI-MS gave
the monomeric molecular ion peak. The other investigations
are also clearly in accordance with the corresponding formula.
Moreover, the composition was further confirmed by the solid-
state structures of 6 and 8 as shown in Figs. 5 and 6. These show
that 6 and 8 are monomeric with similar structural features of
the precursors. However, Ge–E bond lengths in 6 (2.104(7) Å)
and in 8 (2.219(6) Å) are longer than those in the starting
materials. As a result, the fluorine compounds have the shortest
Ge–E bond lengths within this series due to the strong electron-
withdrawing property of the fluorine atom (Ge–S bond length:
2 (2.050(9) Å) < 1 (2.053(6) Å) < 6 (2.104(7) Å); Ge–Se bond
length: 5 (2.176(7) Å) < 4 (2.197(6) Å) < 8 (2.219(6) Å)). Con-
sequently this influences the average Ge–N bond length (2
(1.888 Å) < 1 (1.895 Å) < 6 (1.941 Å); 5 (1.895 Å) < 4 (1.900 Å)
< 8 (1.935 Å)).
Fig. 3 Molecular structure of 2 in the crystal (50% probability thermal
ellipsoids). Selected bond lengths and angles (Њ): Ge(1)–F(1) 1.848(2),
Ge(1)–S(1) 2.050(9), Ge(1)–N(1) 1.892(2), Ge(1)–N(2) 1.884(2); S(1)–
Ge(1)–N(1) 120.14(7), S(1)–Ge(1)–N(2) 119.58(7), S(1)–Ge(1)–F(1)
116.57(8), N(1)–Ge(1)–N(2) 97.69(10), F(1) Ge(1)–N(1) 99.07(9),
F(1)–Ge(1)–N(2), 99.61(9).
Fig. 5 Molecular structure of 6 in the crystal (50% probability thermal
ellipsoids). Selected bond lengths and angles (Њ): Ge(1)–C(6) 2.009(2),
Ge(1)–S(1) 2.104(7), Ge(1)–N(1) 1.930(2), Ge(1)–N(2) 1.952(2); S(1)–
Ge(1)–N(1) 111.54(5), S(1)–Ge(1)–N(2) 110.41(5), S(1)–Ge(1)–C(6)
120.25(6), N(1)–Ge(1)–N(2) 94.15(10), C(6)–Ge(1)–N(1) 107.69(8),
C(6)–Ge(1)–N(2) 109.66(8).
Experimental
General consideration
Fig. 4 Molecular structure of 5 in the crystal (50% probability thermal
ellipsoids). Selected bond lengths and angles (Њ): Ge(1)–F(1) 1.758(3),
Ge(1)–Se(1) 2.176(7), Ge(1)–N(1) 1.886(3), Ge(1)–N(2) 1.898(4);
Se(1)–Ge(1)–N(1) 120.93(11), Se(1)–Ge(1)–N(2) 121.65(11), Se(1)–
Ge(1)–F(1) 116.29(9), N(1)–Ge(1)–N(2) 97.08(16), F(1)–Ge(1)–N(1)
98.72(14), F(1)–Ge(1)–N(2) 97.17(14).
All manipulations were carried out using standard Schlenk
techniques or in a glove box under a nitrogen atmosphere.
Toluene was freshly distilled from Na, hexane from K, di-
chloromethane from CaH2 prior to use. Elemental analyses
were performed by the Analytisches Labor des Instituts für
D a l t o n T r a n s . , 2 0 0 3 , 1 0 9 4 – 1 0 9 8
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stirred for 24 h. After filtration a yellow solution was obtained.
Concentration (ca. 10 ml) and storage of the yellow solution in
a Ϫ32 ЊC freezer for 24 h afforded yellow crystals of 4 (yield
0.53 g, 87%). Mp 230 ЊC (deomp.). Anal. Calc. for C29H41-
ClGeN2Se: C, 57.61; H, 6.83; N, 4.63. Found: C, 57.69; H,
6.92; N, 4.70%. EI-MS: m/z 605 (Mϩ), 590 ([Mϩ ϪMe]), 526
([Mϩ ϪSe]). 1H NMR (C6D6): δ 0.98 (d, 6 H, CHMe2), 1.15 (d, 6
H, CHMe2), 1.47 (d, 6 H, CHMe2), 1.481 (s, 6 H, β-Me), 1.484
(d, 6 H, CHMe2), 3.25–3.32 (sept, 2 H, CHMe2), 3.62–3.70
(sept, 2 H, CHMe2), 5.00 (s, 1 H, γ-CH), 7.08–7.15 (m, 6 H,
2,6-iPr2C6H3). 77Se NMR (C6D6): δ Ϫ287.90.
Synthesis of [{HC(CMeNAr)2}Ge(Se)F] (5)
Both procedures for 5 are similar to those for 2. Colorless
crystals of 5 were obtained. Mp 266 ЊC. Anal. Calc. for C29H41-
FGeN2Se: C, 59.22; H, 7.03; N, 4.76. Found: C, 59.15; H, 7.15;
Fig. 6 Molecular structure of 8 in the crystal (50% probability thermal
ellipsoids; hydrogen atoms are omitted for clarity). Selected bond
lengths and angles (Њ): Ge(1)–C(31) 1.961(5), Ge(1)–Se(1) 2.219(6),
Ge(1)–N(1) 1.941(2), Ge(1)–N(2) 1.930(2); Se(1)–Ge(1)–N(1)
111.55(7), Se(1)–Ge(1)–N(2) 112.08(7), Se(1)–Ge(1)–C(31) 120.95(14),
N(1)–Ge(1)–N(2) 94.00(11), C(31)–Ge(1)–N(1) 106.52(17), C(31)–
Ge(1)–N(2) 108.29(17).
1
N, 4.55%. EI-MS: m/z 589 (Mϩ), 574 ([Mϩ ϪMe]). H NMR
(C6D6): δ 1.04 (d, 6 H, CH(CH3)2), 1.18 (d, 6 H, CH(CH3)2),
1.42–1.55 (t, 18 H, β-Me, CH(CH3)2), 3.05–3.20 (m, 2 H,
CH(CH3)2), 3.40–3.60 (m, 2 H, CH(CH3)2), 4.89 (s, 1 H, γ-CH),
7.02–7.10 (m, 6 H, 2,6-iPr2C6H3). 19F NMR (C6D6): δ 54.2. 77Se
NMR (C6D6): δ Ϫ465.1.
Anorganische Chemie der Universität Göttingen. A Bruker
AM 200 instrument was used to record 1H NMR (200.1 MHz),
77Se NMR (200.1 MHz) and 19F NMR (188.3 MHz) spectra,
with reference to TMS, Me2Se, and BF3(OEt2), respectively.
Mass spectra were obtained on Finnigan Mat 8230. The com-
pounds [HC(CMeNAr)2GeCl]11 and [HC(CMeNAr)2GeF]10
were prepared by literature procedures. Other chemicals were
purchased from Aldrich and used as received.
Synthesis of [{HC(CMeNAr)2}Ge(S)Me] (6)
Route (a): A solution of MeLi (0.65 ml, 1.6 M in ether) was
added to a solution of 1 (0.56 g, 1.0 mmol) in toluene (20 ml) at
Ϫ42 ЊC. The reaction mixture was allowed to warm to room
temperature and was stirred for another 2 h. After filtration and
the addition of hexane (10 ml) to the filtrate, standing of the
solution at room temperature for 2 d afforded yellow crystals of
6 (yield 0.38 g, 71%). Mp 192 ЊC. Anal. Calc. for C30H44GeN2S:
C, 67.06; H, 8.25; N, 5.21. Found: C, 67.03; H, 8.34; N, 4.86%.
EI-MS: m/z 538 (Mϩ), 523 ([Mϩ ϪMe]). 1H NMR (C6D6):
δ 0.76 (s, 3 H, GeMe), 1.01 (d, 6 H, CHMe2), 1.11 (d, 6 H,
CHMe2), 1.19 (d, 6 H, CHMe2), 1.47 (s, 6 H, β-Me), 1.64 (d,
6 H, CHMe2), 2.95–3.05 (sept, 2 H, CHMe2), 4.00–4.15 (sept,
2 H, CHMe2), 4.84 (s, 1 H, γ-CH), 6.95–7.15 (m, 6 H, 2,6-
iPr2C6H3). Route (b): The procedure is the same as that of route
(a) except 2 was used as starting material.
Synthesis of [{HC(CMeNAr)2}Ge(S)Cl] (1)
A solution of 3 (0.53 g, 1.0 mmol) in toluene (20 ml) was added
to a stirred suspension of sulfur (0.03 g, 1.0 mmol) in toluene
(10 ml). The reaction mixture was stirred at room temperature
for 2 d during which time the color changed from yellow to
slightly green. Storage of the reaction mixture at Ϫ32 ЊC for 3 d
afforded greenish crystals of 1 (yield 0.49 g, 88%). Mp 225 ЊC
(decomp). Anal. Calc. for C29H41ClGeN2S: C, 62.45; H, 7.41; N,
5.02. Found: C, 62.31; H, 7.44; N, 5.05%. EI-MS: m/z 558 (Mϩ),
1
543 ([Mϩ ϪMe]). H NMR (C6D6): δ 0.97 (d, 6 H, CHMe2),
Synthesis of [{HC(CMeNAr)2}Ge(Se)Me] (7)
1.13 (d, 6 H, CHMe2), 1.44–1.51 (t, 18 H, CHMe2, β-Me), 3.22–
3.39 (sept, 2 H, CHMe2), 3.50–3.75 (sept, 2 H, CHMe2), 4.96 (s,
1 H, γ-CH), 7.08–7.10 (m, 6 H, 2,6-iPr2C6H3).
7 can be prepared from 4 and 5, respectively. The procedure is
similar to that for 6. Mp 210–213 ЊC (decomp.). Anal. Calc. for
C30H44GeN2Se (584.22): C, 61.67; H, 7.58; N, 4.79. Found: C,
61.5; H, 7.5; N, 4.8. EI-MS: m/z 584 (Mϩ), 569 ([Mϩ ϪMe]), 506
Synthesis of [{HC(CMeNAr)2}Ge(S)F] (2)
1
([Mϩ ϪSe]). H NMR (C6D6): δ 1.06 (d, 6 H, CH(CH3)2), 1.09
Route (a): A solution of 1 (0.56 g, 1.0 mmol) in dichloro-
methane (10 ml) was added to a suspension of Me3SnF (0.18 g,
1.0 mmol) in dichloromethane (10 ml). The reaction mixture
was stirred for 2 d at room temperature. After removal of all
volatiles the residue was extracted with toluene (10 ml). Storage
of the extract in a Ϫ32 ЊC freezer for 24 h afforded colorless
crystals of 2 (yield 0.53 g, 87%). Mp 247 ЊC. Anal. Calc. for
C29H41FGeN2S: C, 64.35; H, 7.63; N, 5.18. Found: C, 64.30; H,
(d, 6 H, CH(CH3)2), 1.10 (s, 3 H, GeMe), 1.25 (d, 6 H,
CH(CH3)2), 1.46 (s, 6 H, β-CH3), 1.63 (d, 6 H, CH(CH3)2),
2.92–3.02 (m, 2 H, CH(CH3)2), 3.80–3.90 (m, 2 H, CH(CH3)2),
4.81 (s, 1 H, γ-CH), 7.01–7.15 (m, 6 H, 2,6-iPr2C6H3). 77Se
NMR (C6D6): δ Ϫ349.
Synthesis of [{HC(CMeNAr)2}Ge(Se)nBu] (8)
1
7.40; N, 5.12%. EI-MS: m/z 542 (Mϩ), 527 ([Mϩ ϪMe]). H
The procedure is the same like that for 7 except nBuLi was used
as the alkylation reagent. Mp 165–168 ЊC. Anal. Calc. for
C33H50GeN2Se (626.20): C, 63.28; H, 8.05; N, 4.47. Found: C,
63.3; H, 8.1; N, 4.5%. EI-MS: m/z 526 (Mϩ), 491 ([Mϩ ϪSeϪ
nBu]). 1H NMR (toluene-d8): δ 0.55 (m, 3 H, (CH2)3CH3), 0.80–
1.10 (m, 6 H, (CH2)3CH3), 0.87 (d, 6 H, CH(CH3)2), 1.01 (d,
6 H, CH(CH3)2), 1.31 (d, 6 H, CH(CH3)2), 1.53 (s, 6 H, β-CH3),
1.61(d, 6 H, CH(CH3)2), 3.20–3.30 (m, 2 H, CH(CH3)2), 4.30–
4.40 (m, 2 H, CH(CH3)2), 4.93 (s, 1 H, γ-CH), 7.01–7.10 (m,
6 H, 2,6-iPr2C6H3). 77Se NMR (toluene-d8): δ Ϫ297.
NMR (C6D6): δ 1.05 (d, 6 H, CHMe2), 1.18 (d, 6 H, CHMe2),
1.42–1.55 (t, 18 H, β-Me, CHMe2), 3.05–3.20 (sept, 2 H,
CHMe2), 3.40–3.55 (sept, 2 H, CHMe2), 4.82 (s, 1 H, γ-CH),
6.95–7.10 (m, 6 H, 2,6-iPr2C6H3). 19F NMR (C6D6): δ 49.23.
Route (b): A solution of 9 (0.51 g, 1.0 mmol) in toluene (10 ml)
was added to a suspension of elemental sulfur (0.03 g,
1.0 mmol) in toluene (10 ml). The reaction mixture was stirred
for 2 d. After filtration and storage of the filtrate in a Ϫ32 ЊC
freezer for 24 h crystals of 2 were afforded in 71% yield.
Synthesis of [{HC(CMeNAr)2}Ge(Se)Cl] (4)
X-Ray crystallography
A solution of 3 (0.53 g, 1.0 mmol) in dichloromethane (10 ml)
was added to a suspension of elemental selenium (0.08 g, 1.0
mmol) in dichloromethane (10 ml). The reaction mixture was
Single crystals of 1, 2, 4, 5, 6 and 8 were taken from the flask
under nitrogen gas and mounted on a glass fiber in a rapidly
cooled perfluoropolyether. Diffraction data were collected
D a l t o n T r a n s . , 2 0 0 3 , 1 0 9 4 – 1 0 9 8
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Table 1 Crystallographic data for compounds 1, 2, 4, 5, 6 and 8
Complex
Formula
1
2
4
5
6
8
C29H41ClGeN2S
C29H41FGeN2Sؒ
C7H8
633.42
Colorless
Monoclinic
P21/n
13.467(2)
16.804(3)
15.668(3)
90
C29H41ClGeN2Seؒ
2CH2Cl2
774.49
Pale yellow
Monoclinic
P21/c
13.176(3)
15.269(3)
18.045(4)
90
C29H41FGeN2Se
C30H44GeN2S
C35H54GeN2Se
Mw
Color
Crystal system
Space group
a/Å
b/Å
c/Å
α/Њ
557.74
Pale yellow
Monoclinic
P21/c
16.880(3)
13.044(3)
13.801(3)
90
588.19
Colorless
Monoclinic
P21/n
21.096(4)
13.380(1)
21.605(4)
90
537.32
Yellow
Monoclinic
P21/n
12.663(3)
19.441(4)
13.350(3)
90
654.35
Yellow
Monoclinic
P21/n
16.714(3)
10.213(2)
18.801(4)
90
β/Њ
108.57(3)
90
2880.5(10)
4
1.286
1.248
92.783(16)
90
3541.5(11)
4
1.188
0.945
91.44(3)
90
3629.2(13)
4
1.417
2.238
101.514(13)
90
5975.9(16)
8
1.308
2.268
117.49(3)
90
2915.4(10)
4
1.224
1.142
90.00(3)
90
3170.1(11)
4
1.371
2.141
γ/Њ
V/Å3
Z
Dc/g cmϪ3
µ/mmϪ1
F(000)
Crystal size/mm
2θ range/Њ
Index range
1176
1344
1584
2432
1144
1376
0.25 × 0.13 × 0.130 1.00 × 0.40 × 0.40 0.50 × 0.50 × 0.20 0.80 × 0.60 × 0.60 0.50 × 0.10 × 0.10 1.00 × 0.60 × 0.40
4.026–55.64
Ϫ22 ≤ h ≤ 22
Ϫ17 ≤ k ≤ 15
Ϫ17 ≤ l ≤ 18
42179
7.30–50.26
Ϫ16 ≤ h ≤ 16
Ϫ8 ≤ k ≤ 20
Ϫ18 ≤ l ≤ 18
9893
4.62–55.10
Ϫ17 ≤ h ≤ 17
Ϫ14 ≤ k ≤ 19
Ϫ23 ≤ l ≤ 23
40850
7.06–45.06
Ϫ22 ≤ h ≤ 22
Ϫ9 ≤ k ≤ 14
Ϫ17 ≤ l ≤ 23
8225
5.42–55.34
Ϫ9 ≤ h ≤ 16
Ϫ25 ≤ k ≤ 25
Ϫ17 ≤ l ≤ 17
32774
7.10–50.02
Ϫ19 ≤ h ≤ 19
Ϫ7 ≤ k ≤ 12
Ϫ14 ≤ l ≤ 22
5791
No.of reflns.
collected
No. of indep.
6747 (0.0457)
6266 (0.0300)
8346 (0.0522)
7806 (0.0925)
6754 (0.0412)
5569 (0.0568)
reflns. (Rint
R, wR2 (I > 2σ(I )) 0.0312, 0.0699
R, wR2 (all data) 0.0369, 0.0721
Goodness of fit, F 2 1.092
)
0.0469, 0.1239
0.0551, 0.1318
1.024
0.0365, 0.0834
0.0553, 0.0929
1.052
0.0440, 0.1075
0.0565, 0.1182
1.059
0.0373, 0.0975
0.0448, 0.1032
1.080
0.0430, 0.1029
0.0523, 0.1091
1.110
Data/restraints/
params.
6747/120/317
6266/0/381
8346/120/371
7806/0/633
6745/120/314
5569/315/350
Largest diff. peak, 0.355, Ϫ0.448
0.821, Ϫ0.736
0.609, Ϫ1.073
0.827, Ϫ0.593
0.953, Ϫ1.063
0.575, Ϫ1.603
hole/e Å3
7 (a) P. Arya, J. Boyer, F. Carré, R. Corriu, G. Lanneau, J. Lapasset,
M. Perrot and C. Priou, Angew. Chem., 1989, 101, 1069; P. Arya,
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1989, 28, 1237; (b) M. C. Kuchta and G. Parkin, J. Chem. Soc.,
Chem. Commun., 1994, 1351; (c) T. Matsumoto, N. Tokitoh
and R. Okazaki, Angew. Chem., 1994, 106, 2418; T. Matsumoto,
N. Tokitoh and R. Okazaki, Angew. Chem., Int. Ed. Engl., 1994, 33,
2316; (d ) N. Tokitoh, T. Matsumoto and R. Okazaki, J. Am. Chem.
Soc., 1997, 119, 2337; (e) S. R. Foley, C. Bensimon and D. S.
Richeson, J. Am. Chem. Soc., 1997, 119, 10359; ( f ) G. Ossig,
A. Meller, C. Brönneke, O. Müller, M. Schäfer and R. Herbst-Irmer,
Organometallics, 1997, 16, 2116; (g) T. Matsumoto, N. R. Tokitoh
and Okazaki, J. Am. Chem. Soc., 1999, 121, 8811; (h) W.-P. Leung,
W.-H. Kwok, Z.-Y. Zhou and T. C. W. Mak, Organometallics, 2000,
19, 296.
9 (a) R. Guilard, C. Ratti, J.-M. Barbe, D. Dubois and K. M. Kadish,
Inorg. Chem., 1991, 30, 1537; (b) Y. Matsuhashi, N. Tokitoh and
R. Okazaki, Organometallics, 1993, 12, 2573; (c) M. C. Kuchta
and G. Parkin, J. Am. Chem. Soc., 1994, 116, 8372; (d ) Y. Zhou and
D. S. Richeson, J. Am. Chem. Soc., 1996, 118, 10850; (e) W.-P.
Leung, W.-H. Kwok, L. T. C. Law, Z.-Y. Zhou and T. C. W. Mak,
J. Chem. Soc., Chem. Commun., 1996, 505; ( f ) M. Saito, N. Tokitoh
and R. Okazaki, J. Am. Chem. Soc., 1997, 119, 11124.
10 Y. Ding, Q. Ma, I. Usón, H. W. Roesky, M. Noltemeyer
and H.-G. Schmidt, J. Am. Chem. Soc., 2002, 124, 854.
11 Y. Ding, H. W. Roesky, M. Noltemeyer, H.-G. Schmidt and
P. P. Power, Organometallics, 2001, 20, 1190.
on a Stoe–Siemens–Huber four-circle diffractometer coupled
to a Siemens CCD area detector at 200(2) K with graphite-
monochromated Mo-Kα radiation (λ = 0.71073 Å). The struc-
tures were solved by direct methods (SHELXS-97) and refined
against F 2 using SHELXL-97.16 All non-hydrogen atoms were
refined anisotropically with similarity and rigid bond restraints.
All hydrogen atoms were included in the refinement in geo-
metrically ideal positions. Crystallographic data are given in
Table 1.
CCDC reference numbers 191193–191195, 192394, 192395
and 198629.
See http://www.rsc.org/suppdata/dt/b2/b211617k/ for crystal-
lographic data in CIF or other electronic format.
Acknowledgements
This work was supported by the Deutsche Forschungsgemein-
schaft and the Fonds der Chemischen Industrie.
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