Donor-stabilized germyl cations. Stable pentacoordinate germanium chloride [PhGe(OCH2CH2NMe2)2][Cl]

Article abstract of DOI:10.1021/om0600745

Intramolecularly coordinated phenylbis[N-(dimethylamino)ethoxy]germanium chloride (1) has been prepared, and its structure has been investigated by ¹H and ¹³C NMR spectroscopy in solutions and by X-ray diffraction analysis in the crystal. Compound 1 tends to ionize in hydrogen-bond-donor solvents, such as CHCl₃, with the formation of the ionic pentacoordinate form [PhGe(OCH₂CH₂NMe ₂)₂][Cl] (1b) dominating over the neutral hexacoordinate form PhGe(OCH₂CH:NMe₂)₂Cl (1a). Crystals grown from CHCl₃ also represent the form 1b. Salt 1b is the first compound stable under ambient conditions containing a free germanium cation of the type [RGeX₂]⁺ (R = Alk, Ar; X = substituent bonded to the germanium atom by a heteroatom: Hal, OR, NR₂) without bulky substituents at the germanium atom in the presence of the highly nucleophilic chloride anion.

Full text of DOI:10.1021/om0600745

Organometallics 2006, 25, 2501-2504
2501
Donor-Stabilized Germyl Cations. Stable Pentacoordinate
Germanium Chloride [PhGe(OCH2CH2NMe2)2][Cl]
Victor N. Khrustalev,*,† Ivan A. Portnyagin,‡ Irina V. Borisova,§ Nikolay N. Zemlyansky,§
Yuri A. Ustynyuk,‡ Mikhail Yu. Antipin,† and Mikhail S. Nechaev‡
A. N. NesmeyanoV Institute of Organoelement Compounds, Russian Academy of Sciences,
Moscow, Russian Federation, Department of Chemistry, M. V. LomonosoV Moscow State UniVersity,
Moscow, Russian Federation, and A. V. TopchieV Institute of Petrochemical Synthesis,
Russian Academy of Sciences, Moscow, Russian Federation
ReceiVed January 24, 2006
Intramolecularly coordinated phenylbis[N-(dimethylamino)ethoxy]germanium chloride (1) has been
1
prepared, and its structure has been investigated by H and 13C NMR spectroscopy in solutions and by
X-ray diffraction analysis in the crystal. Compound 1 tends to ionize in hydrogen-bond-donor solvents,
such as CHCl3, with the formation of the ionic pentacoordinate form [PhGe(OCH2CH2NMe2)2][Cl] (1b)
dominating over the neutral hexacoordinate form PhGe(OCH2CH2NMe2)2Cl (1a). Crystals grown from
CHCl3 also represent the form 1b. Salt 1b is the first compound stable under ambient conditions containing
a free germanium cation of the type [RGeX2]+ (R ) Alk, Ar; X ) substituent bonded to the germanium
atom by a heteroatom: Hal, OR, NR2) without bulky substituents at the germanium atom in the presence
of the highly nucleophilic chloride anion.
licity; (2) to hamper the approach of a nuclephile by sterically
demanding substituents at the E14 center; (3) to stabilize the
cations thermodynamically by introduction of auxiliary NR2 or
OR groups in the side chain, the electron lone pairs of which
could, in principle, be capable of bonding to the empty p-orbital
of the E14 center.
Stable group 14 salts of this kind with highly nucleophilic
anions, such as chloride, can be prepared, as a rule, only in the
presence of bulky ligands directly bonded to the E14 center.3b,l,n,4
Nevertheless, recently, an X-ray diffraction study of the steri-
cally unencumbered silicon complex [(AcN(Me)CH2)2SiCl][Cl]3j
containing a free silyl cation has been reported. The salt [PhGe-
(OCH2CH2NMe2)2][Cl] (1b) considered in the present paper is
the first stable compound containing (i) a cation of the type
[RGeX2]+ (R ) Alk, Ar; X ) substituent bonded to Ge atom
by a heteroatom: Hal, OR, NR2) and (ii) a free germyl cation
Introduction
The ability of heavier main-group elements to accommodate
more than eight electrons in their valence shells, thus forming
so-called hypervalent or hypercoordinate compounds, is well-
established, and the chemistry of such compounds in all its
different facets has been regularly reviewed over the years.
Group 14 elements are in the center of these investigations.1
Compounds containing intramolecularly coordinated ligands
are prominent representatives of this class. We have recently
reported the ability of the â-dimethylaminoethoxy ligand to
stabilize thermodynamically divalent germanium and tin deriva-
tives in the monomeric form under ambient conditions without
involvement of any steric shielding of the E14 (E14 ) group 14
element) atom.2
In this paper, we report on the use of the â-dimethylamino-
ethoxy ligand for the synthesis of a stable compound containing
a pentacoordinate germyl cation, [PhGe(OCH2CH2NMe2)2]+.
The group 14 cations, i.e., silyl, germyl, or stannyl, stabilized
by chelating ligands are of significant current interest.3
Three complementary strategies for the generation of stable
silyl, germyl, or stannyl cations are available: (1) to reduce
the probability of a nucleophilic attack at the cationic center
by the use of counterions and solvents of very low nucleophi-
(3) (a) Jurkschat, K.; Pieper, N.; Seemeyer, S.; Schu¨rmann, M.; Biese-
mans, M.; Verbruggen, I.; Willem, R. Organometallics 2001, 20, 868. (b)
Kost, D.; Kingston, V.; Gostevskii, B.; Ellern, A.; Stalke, D.; Walfort, B.;
Kalikhman, I. Organometallics 2002, 21, 2293. (c) Ru˚zˇicˇka, A.; Dosta´l,
L.; Jambor, R.; Buchta, V.; Brus, J.; C´ısaˇrova´, I.; Holcapek, M.; Holecˇek,
J. Appl. Organomet. Chem. 2002, 16, 315. (d) Ruzˇicˇka, A.; Jambor, R.;
C´ısaˇrova´, I.; Holecˇek, J. Chem.-Eur. J. 2003, 9, 2411. (e) Kost, D.;
Gostevskii, B.; Kocher, N.; Stalke, D.; Kalikhman, I. Angew. Chem., Int.
Ed. 2003, 42, 1023. (f) Kalikhman, I.; Gostevskii, B.; Girshberg, O.;
Sivaramakrishna, A.; Kocher, N.; Stalke, D.; Kost, D. J. Organomet. Chem.
2003, 686, 202. (g) Neculai, A. M.; Neculai, D.; Nikiforov, G. B.; Roesky,
H. W.; Schlicker, C.; Herbst-Irmer, R.; Magull, J.; Noltemeyer, M. Eur. J.
Inorg. Chem. 2003, 3120. (h) Peveling, K.; Henn, M.; Lo¨w, C.; Mehring,
M.; Schu¨rmann, M.; Costisella, B.; Jurkschat, K. Organometallics 2004,
23, 1501. (i) Kasˇna´, B.; Jambor, R.; Dosta´l, L.; Ruzˇicˇka, A.; C´ısarˇova´, I.;
Holecˇek, J. Organometallics 2004, 23, 5300. (j) Kramarova, E. P.;
Korlyukov, A. A.; Bylikin, S. Y.; Schipov, A. G.; Baukov, Y. I.; Kost, D.
Russ. Chem. Bull. 2004, 1135. (k) Dannappel, K.; Schu¨rmann, M.; Costisella,
B.; Jurkschat, K. Organometallics 2005, 24, 1031. (l) Gostevskii, B.; Silbert,
G.; Adear, K.; Sivaramakrishna, A.; Stalke, D.; Deuerlein, S.; Kocher, N.;
Voronkov, M. G.; Kalikhman, I.; Kost, D. Organometallics 2005, 24, 2913.
(m) Mu¨ller, T. AdV. Organomet. Chem. 2005, 53, 155. (n) Kasˇna´, B.;
Jambor, R.; Dosta´l, L.; Kola´rˇova´, L.; C´ısaˇrova´, I.; Holecˇek, J. Organome-
tallics 2006, 25, 148.
* To whom correspondence should be addressed at 28 Vavilov St,
119991, Moscow, Russian Federation. Tel: +7 (495) 135 9343. Fax: +7
(495) 135 5085. E-mail: vkh@xray.ineos.ac.ru.
† Nesmeyanov Institute of Organoelement Compounds.
‡ Lomonosov Moscow State University.
§ Topchiev Institute of Petrochemical Synthesis.
(1) (a) Chemistry of HyperValent Compounds; Akiba, K., Ed.; Wiley-
VCH: Weinheim, Germany, 1999, and references therein. (b) Baukov, Y.
I.; Tandura, S. N. In The Chemistry of Organic Germanium, Tin and Lead
Compounds; John Wiley and Sons, Ltd.: Chichester, 2002; Vol. 2, p 963.
(c) Kost, D.; Kalikhman, I. AdV. Organomet. Chem. 2004, 50, 1.
(2) (a) Zemlyansky, N. N.; Borisova, I. V.; Khrustalev, V. N.; Ustynyuk,
Y. A.; Nechaev, M. S.; Lunin, V. V.; Barrau, J.; Rima, G. Organometallics
2003, 22, 1675. (b) Zemlyansky, N. N.; Borisova, I. V.; Khrustalev, V. N.;
Antipin, M. Y.; Ustynyuk, Y. A.; Nechaev, M. S.; Lunin, V. V. Organo-
metallics 2003, 22, 5441.
(4) Benin, V. A.; Martin, J. C.; Willcott, M. R. Tetrahedron 1997, 53,
10133.
10.1021/om0600745 CCC: $33.50 © 2006 American Chemical Society
Publication on Web 04/11/2006

2502 Organometallics, Vol. 25, No. 10, 2006
KhrustaleV et al.
without bulky substituents at the germanium atom in the
presence of the chloride anion.
Results and Discussion
The compound PhGe(OCH2CH2NMe2)2Cl (1) was prepared
in high yield by the substituent exchange reaction of PhGeCl3
with Et3GeOCH2CH2NMe2 using a 1:2 reagent ratio in THF
(eq 1).
PhGeCl3 + 2 Et3GeOCH2CH2NMe2 THF8
PhGe(OCH2CH2NMe2)2Cl + 2 Et3GeCl (1)
Figure 1. Crystal structure of 1b‚2CHCl3 with 40% probability
ellipsoids (most H atoms are omitted for clarity). The label A
denotes symmetrically equivalent atom relative to the 2-fold axis.
The coordination GerN bonds are shown by double lines and the
H-bonds are shown by dashed lines. Selected bond lengths (Å) and
angles (deg): Ge-O1 1.780(3), Ge-C1 1.912(4), GerN1 2.092(4),
Ge‚‚‚Cl1 4.668(2), O1-Ge-C1 113.8(2), O1-GerN1 85.3(2),
N1fGe-C1 101.1(1), O1-Ge-O1i 132.5(3), N1fGerN1i
157.8(2), O1-GerN1i 85.8(2). Symmetry operation i: 1 - x, y,
1.5 - z.
Complex 1 is a white crystalline solid that is highly sensitive
to traces of moisture. It is slightly soluble in THF and toluene,
highly soluble in CH2Cl2 and CHCl3, and insoluble in hexane
and benzene.
The 1H and 13C NMR spectra of 1 in CDCl3 at room
temperature reveal the association-dissociation equilibrium
between the neutral hexacoordinate form PhGe(OCH2CH2-
NMe2)2Cl (1a) and the ionic pentacoordinate form [PhGe(OCH2-
CH2NMe2)2][Cl] (1b) (eq 2).
4-(tert-butyl)phenyl tridentate ligand (2)4 (the closest Ge‚‚‚Cl
distance is 4.977(7) Å) and (b) the [MamxGe(Me)(But)][I]
(Mamx ) 2,4-di-tert-butyl-6-(N,N-dimethylaminomethyl)phen-
yl) (3)5e and [MamxGe(Me)(Tip)][I] (Tip ) 2,4,6-iPr3C6H2) (4)5g
complexes with the tetracoordinate germanium atoms also
bearing bulky substituents, in which the Ge‚‚‚I distances are
equal to 4.887(1) and 5.160(3) Å, respectively.
The ionic form 1b dominates over the neutral form 1a in a
6.5:1 ratio. The form 1b is manifested as two singlets of the
diastereotopic methyl groups of the nitrogen atom at 2.00 and
2.57 ppm, two multiplets of the diastereotopic protons of the
CH2N groups centered at 2.75 and 3.02 ppm, and a multiplet
The chloride anion is bonded to the chloroform solvate
molecules by hydrogen bonds C-H‚‚‚Cl- (Cl1‚‚‚C1S 3.363(3)
Å, Cl1‚‚‚H1S 2.38 Å, Cl1‚‚‚C1S-H1S 167°) (Figure 1).
It is of interest that in (aza(14)annulene-methylthiolato)-
germanium iodide (5) and (aza(14)annulene-methylselenolato)-
germanium iodide (6) complexes,5d despite the presence of
iodide counterions, the shortest intermolecular Ge‚‚‚X (X ) any
atom of anion or solvent molecules) distances are those between
the germanium atom and the chlorine atoms of one of the solvate
chloroform molecules equal to 4.143(2) and 4.357(2) Å in 5
and 4.170(5) and 4.381(5) Å in 6. The germanium atoms in
complexes 5 and 6 adopt square pyramidal (SP) geometries.
Complex 1b has intrinsic C2 symmetry and occupies a special
position on the 2-fold axis in the crystal structure. Compound
1b is chiral. The enantiomers cocrystallize in the centrosym-
metric space group C2/c.
The geometry of complex 1b corresponds to a distorted
trigonal bipyramid (TBP) with the two â-dimethylaminoethoxy
ligands coordinated in chelating fashion. Two oxygen and one
carbon atom occupy the equatorial positions, whereas two
nitrogen atoms are in the axial positions. This is the most typical
geometry for pentacoordinate bis-chelates with two nitrogen-
donor ligands.6 The distortions are manifested in a deviation of
1
of the CH2O protons centered at 3.97 ppm in the H NMR
spectrum. In the 13C NMR spectrum, the same chemical groups
give rise to two singlets at 43.37 and 44.15 ppm, a singlet at
56.09 ppm, and a singlet at 57.84 ppm, respectively. In contrast,
1
three signals both in the H (a singlet at 2.47 ppm and two
multiplets centered at 2.95 and 3.80 ppm) and the 13C (three
singlets at 41.78, 54.80, and 58.05 ppm) NMR spectra,
corresponding respectively to NMe2, CH2N, and CH2O groups,
belong to the neutral form 1a. All signals are significantly
broadened. The general shape of the spectra points to the fact
that 1a is characterized by a fast exchange of the NMe2 groups
(on the time scale of NMR), while the interconversion between
1a and 1b proceeds at a moderate rate. A more detailed variable-
temperature NMR study of 1 will be the subject of further
investigations.
The structure of 1b was studied by X-ray diffraction analysis.
Single crystals of 1b suitable for X-ray crystallography were
obtained from a CHCl3 solution. The form 1b crystallizes as a
solvate with two chloroform molecules. The crystal structure
of 1b‚2CHCl3 is shown in Figure 1 along with the atomic
numbering scheme and selected bond lengths and angles.
The X-ray diffraction study clearly confirms the ionic nature
of 1b with its well-separated pentacoordinate [PhGe(OCH2CH2-
NMe2)2]+ cations and chloride anions. The closest Ge‚‚‚Cl
distance is 4.668(2) Å, which decisively excludes any bonding
interactions. This is one of the longest Ge+‚‚‚A- (A ) anion)
distances among those reported in the literature.4,5 Longer
Ge+‚‚‚Hal- distances were observed only in (a) a sterically
encumbered germanium complex, in which the pentacoordinate
germyl cation is stabilized by the 2,6-bis(dialkylaminomethyl)-
(5) (a) Baukov, Y. I.; Shipov, A. G.; Smirnova, L. S.; Kramarova, E. P.;
Bylikin, S. Y.; Ovchinnikov, Y. E.; Struchkov, Y. T. J. Organomet. Chem.
1993, 461, 39. (b) Ovchinnikov, Y. E.; Struchkov, Y. T.; Baukov, Y. I.;
Shipov, A. G.; Kramarova, E. P.; Bylikin, S. Y. Russ. Chem. Bull. 1994,
1421. (c) Ovchinnikov, Y. E.; Struchkov, Y. T.; Baukov, Y. I.; Shipov, A.
G.; Bylikin, S. Y. Russ. Chem. Bull. 1994, 1427. (d) Kuchta, M. C.; Parkin,
G. Chem. Commun. 1996, 1669. (e) Schmidt, H.; Keitemeyer, S.; Neumann,
B.; Stammler, H.-G.; Schoeller, W. W.; Jutzi, P. Organometallics 1998,
17, 2149. (f) Cosledan, F.; Castel, A.; Riviere, P.; Satge, J.; Veith, M.;
Huch, V. Organometallics 1998, 17, 2222. (g) Jutzi, P.; Keitemeyer, S.;
Neumann, B.; Stammler, H.-G. Organometallics 1999, 18, 4778. (h)
Ichinohe, M.; Fukui, H.; Sekiguchi, A. Chem. Lett. 2000, 600.
(6) Gillespie, R. J. Molecular Geometry; Van Nostrand Reinhold:
London, 1972.

Donor-Stabilized Germyl Cations
Organometallics, Vol. 25, No. 10, 2006 2503
(i) the NfGerN angle (157.8(2)°) from the ideal value of 180°
and (ii) the equatorial O-Ge-O and C-Ge-O angles from
the ideal value of 120°. Interestingly, the deviation from TBP
geometry for crystal 1b is very similar to that in related
pentacoordinate silicon complexes, as evident from the O-Si-O
and NfSirN angles, which are in the ranges 134.0-137.0°
and 155.0-157.0°, respectively. These values correspond to a
substantial distortion of TBP along the TBPfSP coordinate,
as calculated from the difference between the NfE14rN and
O-E14-O angles [%TBP ) 100(NE14N-OE14O)/60].
Although the Ge‚‚‚Cl distances considerably exceed the sum
of the van der Waals radii of Ge and Cl (∼3.70 Å),7 the chloride
anions apparently induce widening of the O-Ge-O angles
(Figure 1).
The intramolecular GerN coordination bonds in the germyl
cation of 1b (2.092(4) Å) are very close in length to those in
the related neutral hexacoordinate complexes (2.069(4)-
2.132(4) Å).8 However, they are considerably shorter than the
GerN bonds in the sterically hindered pentacoordinate germyl
cation stabilized by the 2,6-bis(dialkylaminomethyl)-4-(tert-
butyl)phenyl tridentate ligand (2.31(2) and 2.36(2) Å).4
In addition, the covalent bonds to germanium in the germyl
cation of 1b are generally shorter than the corresponding bonds
in the related neutral hexacoordinate complexes, which might
be expected in positively charged species.
The geometries of molecules A and C correspond to a
distorted square bipyramid. Two oxygen, one carbon, and one
chlorine atom occupy equatorial positions, and two nitrogen
atoms reside in axial positions. The distortion is manifested in
(i) the deviation of the N-Ge-N angles from the ideal 180°
by about 14.5° and (ii) a slightly nonplanar disposition of the
Ph, Cl, and alkoxy substituents around the germanium atom:
Cl-C-O-O dihedral angles are about 7°. It is important to
stress that the formation of two H‚‚‚Cl- contacts in molecule
C leads to significant lengthening of the Ge-Cl covalent bond
by 0.167 Å. Consequently, the Ge-C, Ge-O, and GerNMe2
distances shorten by 0.013, 0.02, and 0.01 Å, respectively.
The geometry of ionic complex D is discussed above. It
should be stressed that the formation of the H‚‚‚Cl- coordination
bonds in D leads to lengthening of the Ge‚‚‚Cl- contact by 0.219
Å in comparison to B. Shortening of the Ge-C, Ge-O, and
GerNMe2 bonds is not as pronounced as for the A-C pair: it
does not exceed 0.006 Å.
Structure A is energetically more favorable than the ionic
form B, ∆G°(A) - ∆G°(B) ) -6.8 kcal/mol.10 The solvation
of both covalent and ionic molecules A and B with two
chloroform molecules is endothermic, ∆H° ) -6.9 and -14.6
kcal/mol, respectively. Contrary to the nonsolvated molecules,
the solvated ionic form D lies lower in energy than the covalent
form C, ∆G°(D) - ∆G°(C) ) -1.1 kcal/mol. The solvated
ionic form D, observed in the crystal, corresponds to the global
minimum of the potential energy surface. Relative concentra-
tions of two forms D and C in chloroform solutions can be
estimated using equation 3. The value of 6.4:1 perfectly fits
our NMR measurements, which gave a value of 6.5:1. Thus,
calculations confirm the crucial role of solvation with chloroform
for the formation of the ionic form D.
Theoretical DFT Study
Theoretical calculations at the density functional level of
theory (PBE/TZ2p)9 have been performed for covalent A and
ionic B forms of molecule Ph-Ge(OCH2CH2NMe2)2Cl (for
calculation details, structures, and energetic parameters, see the
Supporting Information). Covalent C and ionic D forms of the
solvate Ph-Ge(OCH2CH2NMe2)2Cl‚2CHCl3 have also been
considered. All molecules studied contain two GerNMe2
coordination bonds. The isomers with broken coordination bonds
have been excluded from consideration.
-∆G0
RT
1.1 × 4.18 × 1000
8.31 × 298.15
C(D)
) exp
) exp
) 6.4 (3)
(
)
(
)
C(C)
We have also performed an AIM analysis11 of all molecules
(for details, see the Supporting Information). It should be
stressed that the Ph group takes part in the stabilization of the
positive charge on the germanium atom in the ionic form D.
Calculated ellipticity (ꢀ) of the bond critical point corresponding
to the Ge-C bond is 0.06, indicating some π-bonding between
these two atoms. To compare, ꢀ ) 0 in ethane, 0.23 in benzene,
and 0.45 in ethylene.11
Conclusion
The calculated structure of [Ph-Ge(OCH2CH2NMe2)2][Cl]‚
2CHCl3 (D) and the X-ray data for 1b‚2CHCl3 in the crystal
are in a good agreement. Calculated values of C-H, C-C,
C-N, C-O, Ge-O, and Ge-C bonds differ from X-ray values
by less than 0.05 Å, which is typical for density functional
methods.9 The calculated interatomic distances Ge‚‚‚Cl- and
Cl-‚‚‚H are shorter than in the crystal by 0.69 and 0.12 Å,
respectively. We suppose that this is due to crystal-packing
effects not taken into consideration in the calculations of isolated
molecules, which can strongly affect interatomic distances be-
tween the ionic species. We also suppose that shortening of the
Ge‚‚‚Cl- distance leads to lengthening of GerNMe2 coordina-
tion bonds by about 0.09 Å with respect to the X-ray data.
The data presented above show that the pentacoordinate
germyl cation [PhGe(OCH2CH2NMe2)2]+ can be stabilized by
the electronic effects of the â-dimethylaminoethoxy ligands
without any steric shielding of the germanium atom even in
the presence of the highly nucleophilic chloride anion. The weak
pz-π interaction between the germanium atom and the phenyl
substituent as well as the solvation of the chloride anion by the
chloroform molecules are the factors responsible for the
additional stabilization of the ionic form 1b.
Experimental Section
General Procedures. All manipulations were carried out under
a purified argon atmosphere using standard Schlenk and high-
vacuum-line techniques. The commercially available solvents were
purified by conventional methods and distilled immediately prior
(7) Bondi, A. J. Phys. Chem. 1964, 68, 441.
(8) (a) Mizuta, T.; Yoshida, T.; Miyoshi, K. Inorg. Chim. Acta 1989,
165, 65. (b) Zhu, J.; Huang, T.-S.; Huang, Y.-Q.; Hong, M.-S.; Hu, S.-Z.
Chin. J. Struct. Chem. 1995, 14, 191. (c) Chen, M.-D.; Zhu, J.; Hu, S.-Z.
Main Group Metal Chem. 1999, 22, 105.
(9) Perdew, J. P.; Burke, K.; Ernzerhof, M. Phys. ReV. Lett. 1996, 77,
3865.
(10) Cramer, C. J. Essentials of Computational Chemistry: Theories and
Models, 2nd ed.; John Wiley and Sons, Ltd.: Chichester, 2004.
(11) Bader, R. F. W. Atoms in Molecules: A Quantum Theory; Oxford
University Press: New York, 1990.

2504 Organometallics, Vol. 25, No. 10, 2006
KhrustaleV et al.
Table 1. Crystallographic Data for 1b‚2CHCl3
to use. The PhGeCl3 was purchased from Aldrich. The Et3GeOCH2-
CH2NMe2 was synthesized as described earlier.2a NMR spectra were
recorded on a Bruker AM-360 NMR spectrometer at 360.134 MHz
(1H) and 90.555 MHz (13C) in CDCl3. Chemical shifts are relative
to SiMe4 for H and C or indirectly referenced to TMS via the solvent
signals. Accuracy of chemical shift measurements is (0.01 ppm
(1H) and (0.05 ppm (13C). The melting point was measured in a
sealed capillary using a SANYO Gallenkamp PLC melting point
apparatus without any additional corrections. The elemental analysis
was performed on a Carlo Erba EA1108 CHNS-O elemental
analyzer.
empirical formula
fw
C16H27N2O2Cl7Ge
600.14
cryst syst
space group
a (Å)
b (Å)
c (Å)
monoclinic
C2/c
17.6994(10)
13.0612(10)
11.8471(8)
103.055(2)
2668.0(3)
4
â (deg)
V (Å3)
Z
dc (g cm-3
)
1.494
1.864
µ (mm-1
)
Phenylbis[N-(dimethylamino)ethoxy]germanium Chloride (1).
A solution of Et3GeOCH2CH2NMe2 (4.63 g, 18.70 mmol) in THF
(30 mL) was added slowly to a stirred solution of PhGeCl3 (2.39
g, 9.34 mmol) in THF (20 mL) at room temperature. A large amount
of white precipitate immediately appeared. After stirring for 2.5 h
the white precipitate was filtered, washed with THF, and dried in
vacuo. The yield of white solid is 3.24 g (96%). Mp: 193 °C (with
dec). Anal. Calcd for C14H25N2O2ClGe (Mr ) 361.40): C, 46.53;
θ range (deg)
1.96 to 30.05
15 232/3876/0.051
3021
0.070; 0.083
0.207; 0.225
no. of measd/indep reflns/Rint
no. of reflns with I > 2σ(I)
R1; wR2 (I > 2σ(I))
R1; wR2 (all data)
fixed thermal parameters. All calculations were carried out using
the SHELXTL PLUS program (PC Version 5.0).13 Crystallographic
data for 1b‚2CHCl3 have been deposited with the Cambridge
Crystallographic Data Center, CCDC 279030. Copies of this
information may be obtained free of charge from the Director,
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK (fax +44 1223
336033; e-mail deposit@ccdc.cam.ac.uk or www.ccdc.cam.ac.uk).
1
H, 6.97; N, 7.75. Found: C, 46.31; H, 7.23; N, 7.53. H NMR
(CDCl3): for 1a δ 2.47 (s, 12H, NMe2), 2.95 (m, br, 4H, CH2N),
3.80 (m, br, 4H, CH2O); for 1b δ 2.00, 2.57 (two s, 12H, NMe2),
2.75, 3.02 (two m, br, 4H, CH2N), 3.97 (m, br, 4H, CH2O); 7.40-
7.43 (m, Ph) (for both forms). 13C NMR (CDCl3): for 1a δ 42.46
(Me2N), 54.80 (CH2N), 58.05 (CH2O), 127.25 (m-Ph) (registration
of the remaining Ph signals for 1a is not possible due to their low
intensity); for 1b δ 43.37, 44.15 (Me2N), 56.10 (CH2N), 57.84
(CH2O); 127.04 (ipso-Ph), 128.24 (m-Ph), 130.77 (p-Ph), 130.96
(o-Ph).
X-ray Crystal Structure Analysis. Data were collected at 120
K on a Bruker three-circle diffractometer equipped with a SMART
1000 CCD detector and corrected for Lorentz and polarization
effects and for absorption.12 For details, see Table 1. The structure
was solved by direct methods and refined by a full-matrix least-
squares technique on F2 with anisotropic displacement parameters
for all non-H atoms. The unit cell contains two solvate chloroform
molecules, which are disordered over two sites by rotation around
the C-H bond, with the occupancies of 0.7:0.3. The H atoms were
placed in calculated positions and refined in the riding mode with
Acknowledgment. This work was financially supported by
the Russian Foundation for Basic Research (Projects Nos. 04-
03-32662 and 04-03-32549) and the Russian Academy of
Sciences within the frame of the subprogram “Theoretical and
experimental study of chemical bonding and mechanisms of
chemical reactions and processes”. We thank Dr. M. G.
Kuznetsova for the multinuclear NMR measurements.
Supporting Information Available: Tables of atom coordi-
nates, bond lengths, bond and torsion angles, anisotropic displace-
ment parameters for 1b‚2CHCl3, and quantum-chemical calcula-
tions. This material is available free of charge via the Internet at
http://pubs.acs.org.
OM0600745
(12) Sheldrick, G. M. SADABS 2.01, Bruker/Siemens Area Detector
Absorption Correction Program; Bruker AXS Inc.: Madison, WI, 1998.
(13) Sheldrick, G. M. SHELXTL 5.10; Bruker AXS Inc.: Madison, WI,
1998.