Stable germylenes derived from 1,2-Bis(arylimino)acenaphthenes

Article abstract of DOI:10.1021/om0497846

Metal exchange reactions of the magnesium complexes (dpp-BIAN)Mg(THF) _n, (dtb-BIAN)-Mg(THF)_n, and (bph-BIAN)Mg(THF)_n with GeCl₂(dioxane) afford the stable germylenes (dpp-BIAN)Ge (1), (dtb-BIAN)Ge(Et₂O) (2), and (bph-BIAN)Ge (3), respectively (dpp-BIAN = 1,2-[(2,6-iPr₂C₆H₃)N]₂C ₁₂H₆, dtb-BIAN = 1,2-[(2,5-tBu₂C ₆H₃)N]₂C₁₂H₆, bph-BIAN = 1,2-[(2-PhC₆H₄)N]₂C₁₂H₆). Compound 1 is also obtained from (dpp-BIAN)Na₄ and GeCl₄ in Et₂O. The germylenes 1-3 were characterized by elemental analyses, ¹H NMR, ¹³C NMR, and IR spectroscopy, and X-ray crystal structure analyses. In the monomeric molecules the two imino nitrogen atoms coordinate the germanium atom. The aryl(N) groups are arranged rather orthogonal to the acenaphthenediimine plane. Compound 3 shows an anti geometry with the ortho phenyl substituents of both N-phenyl rings positioned on opposite sides of the acenaphthenediimine plane. The bite angles N-Ge-N are 85.2° (1) and 85.0° (3), respectively. The Ge-N bond distances in 1-3 range from 1.878 to 1.915 A.

Full text of DOI:10.1021/om0497846

3714
Organometallics 2004, 23, 3714-3718
Sta ble Ger m ylen es Der ived fr om
1,2-Bis(a r ylim in o)a cen a p h th en es
Igor L. Fedushkin,* Alexandra A. Skatova, Valentina A. Chudakova,
Natalie M. Khvoinova, and Andrey Yu. Baurin
G. A. Razuvaev Institute of Organometallic Chemistry of the Russian Academy of Sciences,
Tropinina 49, 603950 Nizhny Novgorod, GSP-445, Russia
Sebastian Dechert, Markus Hummert, and Herbert Schumann*
Institut fu¨r Chemie der Technischen Universita¨t Berlin, Strasse des 17. J uni 135,
D-10623 Berlin, Germany
Received March 26, 2004
Metal exchange reactions of the magnesium complexes (dpp-BIAN)Mg(THF)n, (dtb-BIAN)-
Mg(THF)n, and (bph-BIAN)Mg(THF)n with GeCl2(dioxane) afford the stable germylenes (dpp-
BIAN)Ge (1), (dtb-BIAN)Ge(Et2O) (2), and (bph-BIAN)Ge (3), respectively (dpp-BIAN ) 1,2-
[(2,6-iPr2C6H3)N]2C12H6, dtb-BIAN ) 1,2-[(2,5-tBu2C6H3)N]2C12H6, bph-BIAN ) 1,2-[(2-
PhC6H4)N]2C12H6). Compound 1 is also obtained from (dpp-BIAN)Na4 and GeCl4 in Et2O.
1
The germylenes 1-3 were characterized by elemental analyses, H NMR, 13C NMR, and IR
spectroscopy, and X-ray crystal structure analyses. In the monomeric molecules the two
imino nitrogen atoms coordinate the germanium atom. The aryl(N) groups are arranged
rather orthogonal to the acenaphthenediimine plane. Compound 3 shows an anti geometry
with the ortho phenyl substituents of both N-phenyl rings positioned on opposite sides of
the acenaphthenediimine plane. The bite angles N-Ge-N are 85.2° (1) and 85.0° (3),
respectively. The Ge-N bond distances in 1-3 range from 1.878 to 1.915 Å.
In tr od u ction
compounds. Despite this principal knowledge, until now,
only six basic types of such compounds (Chart 1) were
described in the literature, the imidazogermoline-2-
ylidene (I),5 its benzo- (II),6 pyrido- (III),7 naphtho- (IV),8
and tropo-annulated9 analogues (V), and the ketoimi-
nate10 species (VI).
In the past decade, 1,2-bis[(2,6-diisopropylphenyl)-
imino]acenaphthene (dpp-BIAN) was a ligand, which
was mostly used in the coordination chemistry of
The present widespread interest in mononuclear
compounds of divalent germanium is caused not only
by the significance of such compounds in the funda-
mental chemical research1 but also by the fact that they
were recognized as versatile reagents in a number of
important transformation reactions of organic sub-
strates involving oxidation, addition, and insertion
reactions.2 Nitrogen-based ligands that stabilize the
divalent state of group 14 elements as a result of the
σ-acceptor character of their N atoms played an impor-
tant role in the increasing development of the chemistry
of divalent carbon, silicon, germanium, and tin.3 Fur-
thermore, theoretical and experimental results4 indicate
that molecular structures with delocalized heterocyclic
π-systems improve the stability of divalent germanium
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* To whom correspondence should be addressed. E-mail: (I.L.F.)
igorfed@imoc.sinn.ru; (H.S.) schumann@chem.tu-berlin.de.
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10.1021/om0497846 CCC: $27.50 © 2004 American Chemical Society
Publication on Web 06/24/2004

Stable Germylenes from Acenaphthenes
Organometallics, Vol. 23, No. 15, 2004 3715
Ch a r t 1
Sch em e 1
transition metals.11 Recently, we reported on the prepa-
ration of two analogous ligands, 1,2-bis[(2,5-di-tert-
butylphenyl)imino]acenaphthene (dtb-BIAN) and 1,2-
bis[(2-biphenyl)imino]acenaphthene (bph-BIAN).12 The
reduction of dpp-BIAN, dtb-BIAN, and bph-BIAN with
activated Mg or Ca in THF affords the respective
monomeric metal complexes (Ar-BIAN)M(THF)n (M )
Mg, Ca) with dianionic ligands.12,13 The use of sodium
metal as reductive agent for dpp-BIAN causes the
formation of sodium complexes containing not only the
dianion but also the mono-, tri-, and tetraanion of the
dpp-BIAN ligand.14
When we started our work on metal complexes with
anionic Ar-BIAN ligands, we intended to prepare mon-
omeric, highly reactive compounds, which in turn would
be able to act as reducing as well as oxidizing agents.
Thus, we could demonstrate that the complex (dpp-
BIAN)Mg(THF)3 serves well as reducing agent toward
aromatic ketones such as diphenyl ketone and 9-(10H)-
anthracenone15 and reacts by way of an oxidative
addition reaction with CH-acidic compounds such as
phenylacetylene.16 Continuing our studies on the chemi-
cal behavior of Ar-BIAN magnesium complexes, we
suggested that these complexes may also be suitable for
metal exchange reactions and that the dianionic Ar-
BIAN2- ligand with its delocalized heterocyclic π-system
should be able to stabilize metals in low-valent states.
Here we report on the synthesis of germylenes of the
type (Ar-BIAN)Ge by reacting the corresponding (Ar-
BIAN)Mg(THF)n complexes with GeCl2(dioxane) or by
reduction of GeCl4 with (dpp-BIAN)Na4.
Resu lts a n d Discu ssion
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A.; Rzaigui, M.; Bouachir, F. Tetrahedron Lett. 2000, 41, 7199. (q)
Ragaini, F.; Cenini, S.; Borsani, E.; Dompe, M.; Gallo, E.; Moret, M.
Organometallics 2001, 20, 3390. (r) Kannan, S.; J ames, A. J .; Sharp,
P. R. Polyhedron 2000, 19, 155. (s) Strauch, J . W.; Erker, G.; Kehr,
G.; Fro¨hlich, R. Angew. Chem. 2002, 114, 2662; Angew. Chem., Int.
Ed. 2002, 41, 2543. (t) Bellachioma, G.; Binotti, B.; Cardaci, G.;
Carfagna, C.; Macchioni, A.; Sabatini, S.; Zuccaccia, C. Inorg. Chim.
Acta 2002, 330, 44. (u) El-Ayaan, U.; Paulovicova, A.; Fukuda, Yu. J .
Mol. Struct. 2003, 645, 205. (v) van Belzen, R.; Elsevier, C. J .; Dedieu,
A.; Veldman, N.; Spek, A. L. Organometallics 2003, 22, 722.
Syn th esis of (d p p -BIAN)Ge, (d tb-BIAN)Ge.Et2O,
a n d (bp h -BIAN)Ge. The reduction of the 1,2-bis-
(arylimino)acenaphthene ligands dpp-BIAN, dtb-BIAN,
and bph-BIAN (dpp-BIAN ) 1,2-[(2,6-iPr2C6H3)N]2C12H6,
dtb-BIAN ) 1,2-[(2,5-tBu2C6H3)N]2C12H6, bph-BIAN )
1,2-[(2-PhC6H4)N]2C12H6) with activated metallic mag-
nesium in THF affords solutions containing the Mg
complexes (dpp-BIAN)Mg(THF)n,13 (dtb-BIAN)Mg-
(THF)n, and (bph-BIAN)Mg(THF)n,12 which we used in
situ for reactions with GeCl2(dioxane). In each case, the
addition of GeCl2(dioxane) to the green solutions of these
magnesium complexes caused a rapid change in color
to deep red. From these solutions the germylenes (dpp-
BIAN)Ge (1), (dtb-BIAN)Ge‚Et2O (2), and (bph-BIAN)-
Ge (3) were isolated as stable, crystalline, deep red
compounds by crystallization from THF (1), diethyl
ether (2), or THF (3), respectively. Germylene 1 was also
obtained by reduction of GeCl4 with a suspension of
14
(dpp-BIAN)Na4 in Et2O freshly prepared from dpp-
BIAN (0.5 g, 1.00 mmol) and excess sodium (Scheme
1).
The IR spectra of 1, 2, and 3 confirm the dianionic
character of the respective Ar-BIAN ligands. Whereas
in the IR spectra of the free ligands the ν(CdN)
(12) Fedushkin, I. L.; Chudakova, V. A.; Skatova, A. A.; Khvoinova,
N. M.; Kurskii, Yu., A.; Glukhova, T. A.; Fukin, G. K.; Dechert, S.;
Hummert, M.; Schumann H. Z. Anorg. Allg. Chem. 2004, 630, 501.
(13) Fedushkin, I. L.; Skatova, A. A.; Chudakova, V. A.; Fukin, G.
K.; Dechert, S.; Schumann, H. Eur. J . Inorg. Chem. 2003, 3336.
(14) (a) Fedushkin, I. L.; Skatova, A. A.; Chudakova, V. A.; Fukin,
G. K. Angew. Chem. 2003, 115, 3416; Angew. Chem., Int. Ed. 2003,
42, 3294. (b) Fedushkin, I. L.; Skatova, A. A.; Chudakova, V. A.;
Cherkasov, V. K.; Fukin, G. K.; Lopatin, M. A. Eur. J . Inorg. Chem.
2004, 388.
(15) Fedushkin, I. L.; Skatova, A. A.; Cherkasov, V. K.; Chudakova,
V. A.; Dechert, S.; Hummert, M.; Schumann, H. Chem. Eur. J . 2003,
5778.
(16) Fedushkin, I. L.; Khvoinova, N. M.; Skatova, A. A.; Fukin, G.
K. Angew. Chem. 2003, 115, 5381; Angew. Chem., Int. Ed. 2003, 42,
5223.

3716 Organometallics, Vol. 23, No. 15, 2004
Fedushkin et al.
Sch em e 2
vibrations, ranging from 1600 to 1700 cm-1, cause the
strongest absorptions12,17 and the corresponding vibra-
tions of the complex [(dpp-BIAN)CuBr]217 in which dpp-
BIAN acts as neutral ligand are shifted only little to
lower wavenumbers, these ν(CdN) vibrations are nearly
absent in the spectra of 1, 2, and 3.
1
In the H NMR spectrum of 1 the methyl protons of
the four isopropyl groups give rise for two doublets
centered at 1.28 and 1.03 ppm due to the restricted
rotation of the 2,6-iPr2C6H3 groups. The septet at 3.47
ppm is assigned to the methine protons. All aromatic
protons appear as broad signals ranging from 6.5 to 7.5
ppm. The 13C NMR spectrum clearly shows the 14
signals which are expected for the molecules of 1
possessing two mirror planes, one bisecting the N-Ge-N
angle and the other running along the N-Ge-N plane.
In the 1H NMR spectrum of 2 recorded in C6D6, the
methyl protons of the tert-butyl substituents give rise
to one broad signal at 1.21 ppm and the signals of the
ring protons are also extremely broadened. The spec-
trum obtained from a THF-d8 solution of 2 did not show
any assignable signals. The broadening of all the signals
can be explained by a dynamic interconversion between
syn and anti isomers of 2 since, in contrast to 1, the
absence of a substituent in the second ortho position of
the phenyl rings allows these rings to rotate by 180°
(Scheme 2). It should be noted here that in solutions of
F igu r e 1. ORTEP presentation of the molecular structure
of 1. Thermal ellipsoids drawn at 30% probability. The
hydrogen atoms are omitted. Selected bond lengths (Å) and
angles (deg): Ge-N(1) 1.896(3), Ge-N(2) 1.885(3), N(1)-
C(13) 1.425(4), N(2)-C(25), 1.432(5), C(1)-C(2) 1.381(5),
C(1)-C(5) 1.458(5), C(3)-C(12) 1.376(5), C(3)-C(4) 1.415-
(5), C(4)-C(5) 1.422(5), C(5)-C(6) 1.372(5), C(7)-C(8)
1.380(6), C(8)-C(9) 1.422(6), C(10)-C(11) 1.367(6), C(11)-
C(12) 1.432(5), C(13)-C(14) 1.408(5), C(4)-C(9) 1.404(5),
N(1)-C(1) 1.374(4), C(6)-C(7) 1.426(6), N(2)-C(2) 1.370-
(4), C(9)-C(10) 1.422(6), C(2)-C(3) 1.473(5), C(13)-C(18)
1.407(5); N(2)-Ge-N(1) 85.20(12), C(1)-N(1)-Ge 112.0-
(2), C(2)-N(2)-Ge 112.0(2), C(25)-N(2)-Ge 126.8(2), C(2)-
N(2)-C(25) 121.1(3), C(13)-N(1)-Ge 125.7(2), C(1)-N(1)-
C(13) 122.4(3).
Ta ble 1. Cr ysta l Da ta a n d Str u ctu r e Refin em en t
Deta ils for 1 a n d 3
1
3
empirical formula
fw
C
36H40GeN2
C36H24GeN2
557.16
573.29
cryst syst
monoclinic
P21/n (No. 14)
a ) 12.9536(2)
monoclinic
C2/c (No. 15)
a ) 15.7687(5)
12
the starting magnesium complex (dtb-BIAN)Mg(THF)2
space group
unit cell dimens,
Å, deg
the presence of syn and anti isomers (2:1 ratio) could
1
be proved by H NMR spectroscopy. The room-temper-
b ) 18.5400(2)
c ) 13.8698(1)
â ) 110.409(1)
3121.87(6)
4
b ) 11.0059(3)
c ) 16.5298(6)
â ) 110.870(1)
2680.51(15)
4
1.381
1.171
1144
ature 13C NMR spectrum of 2 shows very broadened
1
resonances. The H NMR spectrum of 3 in C6D6 is not
volume, Å3
expressive because the signals of the 12 nonequivalent
aromatic protons appear in the very narrow range of
6.95-7.60 ppm. However, the 13C NMR spectrum of 3
shows 17 signals, thus indicating the presence of only
one isomer in solution.
Molecu la r Str u ctu r es of Com p ou n d s 1 a n d 3. The
crystal and structure refinement data of the compounds
are listed in Table 1, and their molecular structures are
depicted in Figures 1 and 2. Refinement of the data of
2 did not give satisfactory results. Therefore those data
are not discussed. They are listed in the Supporting
Information.
Compounds 1 and 3 crystallize in the monoclinic space
groups P21/n and C2/c, respectively. In each case, the
unit cell contains four molecules. According to the space
group, the crystal structure of 3 shows C2 symmetry.
Because of the unsymmetrical substitution of the
phenyl rings in 3, the molecule can show syn or anti
configuration. Germylene 3 exhibits anti configuration.
The bite angles N-Ge-N of 1 (85.2°) and 3 (85.0°) are
only slightly smaller than that in 1,3,2-diazagermoline-
Z
density(calcd), g/cm3 1.220
µ, mm-1
F(000)
1.007
1208
cryst size, mm3
θ range for data
collection, deg
index ranges
0.60 × 0.34 × 0.14
0.28 × 0.28 × 0.08
1.85-27.50
2.31-26.00
-16 e h e 16
-24 e k e 18
-13 e l e 18
-19 e h e 19
-9 e k e 13
-17 e l e 20
6935
no. of reflns collected 23 233
no. of indep reflns
max./min. transmn
7139 [Rint ) 0.0953] 2564 [Rint ) 0.0870]
0.9002/0.1728
0.9319/0.5533
2564/0/178
no. of data/restraints/ 7139/0/360
params
goodness-of-fit on F2 1.002
1.007
final R indices
[I>2σ(I)]
R1 ) 0.0660
R1 ) 0.0596
wR2 ) 0.1497
R1 ) 0.1212
wR2 ) 0.1748
0.906/-1.161
wR2 ) 0.0985
R1 ) 0.1342
wR2 ) 0.1196
0.521/-0.751
R indices (all data)
largest diff peak/
hole, e Å-3
2-ylidene C2H2[N(CH2tBu)]2Ge (87.7°).7 The Ge-N bond
lengths in 1 [1.896(3) Å] and 3 [1.878(3) Å] are longer
than those in C2H2[N(CH2tBu)]2Ge [1.808(1) Å],7 C6H4-
[N(SiMe3)]2Ge [1.866(9),186.1(8) Å],6 and C10H6(NiPr)2-
Ge [1.8417(17), 1.8420(16) Å],8 but are shorter than the
(17) (a) Paulovicova, A. A.; El-Ayaan, U.; Shibayama, K.; Morita,
T.; Fukuda, Y. Eur. J . Inorg. Chem. 2001, 2641. (b) Paulovicova, A.
A.; El-Ayaan, U.; Umezava, K.; Vithana, C.; Ohashi, Y.; Fukuda, Y.
Inorg. Chim. Acta 2002, 339, 209.

Stable Germylenes from Acenaphthenes
Organometallics, Vol. 23, No. 15, 2004 3717
C(18) in 1 and from the atoms C(8)-C(13) in 3. Plane 3
is formed from the atoms C(25)-C(30) in 1.
In 1 and 2 the phenyl rings are almost orthogonal to
the diimine plane, whereas in 3 the absence of a second
substituent at the phenyl ring allows a rotation around
the N-C(ipso) bond to a certain degree. The dihedral
angle between the phenyl rings of the diphenyl moiety
is 64.8(2)°.
Exp er im en ta l Section
Gen er a l Rem a r k s. All manipulations were carried out
under vacuum using Schlenk ampules. The solvents Et2O,
THF, benzene, and toluene were dried by distillation from
sodium/benzophenone. The deuterated solvents THF-d8 and
C6D6 (Aldrich) used for the NMR measurements were dried
with sodium/benzophenone at ambient temperature. They
were, just prior to use, condensed under vacuum into the NMR
tubes already containing the respective compound. GeCl2-
(dioxane) was purchased from ABCR. The melting points were
measured in sealed capillaries. The IR spectra were recorded
on a Specord M80 spectrometer; the 1H and 13C{1H} NMR
spectra, on a Bruker DPX-200 NMR spectrometer (1H, 200
MHz; 13C, 50.32 MHz). Chemical shifts are reported in ppm
relative to the 1H and 13C{1H} residues of the deuterated
solvents.
F igu r e 2. ORTEP presentation of the molecular structure
of 3. Thermal ellipsoids drawn at 30% probability. The
hydrogen atoms are omitted. Selected bond lengths (Å) and
angles (deg): Ge-N(1) 1.878(3), N(1)-C(1) 1.382(5), C(1)-
C(1#) 1.395(8), C(1)-C(2) 1.457(6), C(2)-C(7) 1.416(5),
C(3)-C(4) 1.421(6), C(5)-C(6) 1.414(6), C(6)-C(7) 1.408-
(8), C(7)-C(2) 1.416(5), C(8)-C(13) 1.380(6), C(9)-C(10)
1.406(6), C(9)-C(14) 1.486(6), C(11)-C(12) 1.369(7), C(12)-
C(13) 1.389(6), C(14)-C(15) 1.391(7), C(15)-C(16) 1.379-
(7), C(17)-C(18) 1.356(8), C(18)-C(19) 1.383(7), N-C(8)
1.427(5), C(8)-C(9) 1.390(6), C(2)-C(3) 1.370(6), C(10)-
C(11) 1.364(7), C(4)-C(5) 1.368(7), C(14)-C(19) 1.391(7),
C(6)-C(5) 1.414(6), C(16)-C(17) 1.397(9); N(1)-Ge-N(1#)
85.0(2), C(1)-N(1#)-C(8) 121.1(3), C(8)-N(1)-Ge 125.6-
(3), N(1)-C(1)-C(1#) 114.4(2), C(1)-N(1)-Ge 113.0(3),
N(1)-C(1)-C(2) 136.2(4).
Syn th esis of (d p p -BIAN)Ge (1). (a ) F r om (d p p -BIAN)-
Mg(THF )n a n d GeCl2 (d ioxa n e). To a solution of (dpp-BIAN)-
13
Mg(THF)n in THF (freshly prepared from 0.5 g (1.00 mmol)
of BIAN and activated magnesium) was added GeCl2(C4H8O)
(0.23 g, 1.0 mmol). The color of the solution quickly changed
from emerald-green to red-brown. When the change in color
was finished, the volatile components were removed under
vacuum and the solid residue was digested with toluene. The
remaining MgCl2 was separated by decantation. Concentration
of the toluene solution under vacuum afforded 1 (0.31 g, 55%)
as red crystals.
(b) F r om (d p p -BIAN)Na 4 a n d GeCl4. To a cooled (-30 °C)
suspension of (dpp-BIAN)Na414 in Et2O (freshly prepared from
dpp-BIAN (0.5 g, 1.00 mmol) and excess sodium) was added
GeCl4 (0.21 g, 1.00 mmol) by condensation in a vacuum.
Warming up the reaction mixture to ambient temperature with
shaking caused gradual dissolution of the powdery, brick-red
(dpp-BIAN)Na4, producing a red solution and a fine colorless
powder. The mixture was stirred at 20 °C for 1 h. Then all
volatiles were removed under vacuum at ambient temperature
within 30 min. To the remaining solid residue toluene (45 mL)
was added. The mixture was heated to 70 °C for 10 min and
was then cooled to ambient temperature and subsequently
centrifuged. The red solution was decanted from the settled
NaCl and was reduced in volume to 10 mL by evaporation of
the solvent in a vacuum. From this concentrated toluene
solution compound 1 (0.29 g, 51%) separated as deep red
crystals. Mp > 235 °C (dec). IR (Nujol): 1670 w, 1610 m, 1580
m, 1550 w, 1520 m, 1320 s, 1250 m, 1210 w, 1170 m, 1100 w,
1050 w, 1030 w, 930 m, 810 m, 800 m, 760 s, 680 w, 620 w,
Ge-N distances in the tropo-annulated three-coordinate
germylene [1,2-C7H5(N-iPr)2]GeCl [av 1.956(4) Å].9 They
are in the range of the Ge-N distances in [(Me3-
Si)2N]2Ge [1.878(5), 1.873(5) Å].18
The comparison of the N-C and C-C bond distances
within the metallacycles Ge-N(1)-C(1)-C(2)-N(2) of
1 and 3 with those of the respective magnesium- and
calcium-containing metallacycles in (dpp-BIAN)Mg-
(THF)2,13a (dtb-BIAN)Mg(THF)2,12 and (bph-BIAN)Ca-
12
(THF)3 shows that in the germylenes these distances
are somewhat shorter than in the alkaline earth com-
plexes. This fact may be explained by a more effective
overlap of the empty p-orbitals of germanium(II) with
the orbitals containing the π-electrons of the CdC
double bond and the electron pairs of the nitrogen
atoms.
The dihedral angles formed between the phenyl rings
attached to the N atoms and the plane formed by the
diimine portion are listed in Table 2.
530 w cm-1
.
1H NMR (C6D6): δ 1.06 (d, 12H, 3J ) 6.8 Hz),
3
1.28 (d, 12H, 3J ) 6.8 Hz), 3.47 (spt, 4H, J ) 6.8 Hz), 6.51 (s,
3
br, 2H), 6.85 (s, br, 2H), 1.06 (d, 12H, J ) 6.8 Hz), 6.95-7.53
(m, br, 8H). 13C NMR (C6D6): δ 23.52, 25.88, 28.57, 123.81,
125.46, 125.88, 127.61, 127.98, 128.10, 129.10, 131.44, 132.18,
137.65, 144.96. Anal. Calcd for C36H40N2Ge (573.29): C, 75.42;
H, 7.03. Found: C, 74.44; H, 7.09.
Ta ble 2. Dih ed r a l An gles in 1 a n d 3
1
3
plane1/plane2
plane1/plane3
89.16(16)
86.21(13)
59.64(19)
Syn th esis of (d tb-BIAN)Ge‚Et2O (2). To a solution of (dtb-
12
BIAN)Mg(THF)n in THF (freshly prepared from dtb-BIAN
(0.56 g, 1.00 mmol) and activated magnesium) was added
GeCl2(dioxane) (0.23 g, 1.00 mmol). The color of the solution
quickly turned from emerald-green to red-brown. When the
change in color was finished, the solvent was removed under
vacuum and diethyl ether (40 mL) was added to the remaining
solid. The suspension formed was filtered to separate the
Plane 1 is formed from the atoms C(1)-C(12), N(1),
N(2), and Ge in 1 and from the atoms C(1)-C(7), N(1),
and Ge in 3. Plane 2 is formed from the atoms C(13)-
(18) Chorley, R. W.; Hitchcock, P. B.; Lappert, F. M.; Leung, W.;
Power, P. P.; Olmstead, M. M. Inorg. Chim. Acta 1992, 198.

3718 Organometallics, Vol. 23, No. 15, 2004
Fedushkin et al.
residual MgCl2. On standing of the red solution at ambient
temperature, compound 2 (0.30 g, 53%) separated as deep red
crystals. Mp ) 219 °C. IR (Nujol): 1610 m, 1550 m, 1330 w,
methods using SHELXS-9719 and were refined on F2 using
SHELXL-97.20 All non-hydrogen atoms were refined anisotro-
pically, and the hydrogen atoms were placed in calculated
positions and assigned to an isotropic displacement parameter
of 0.08 Å2. SADABS21 was used to perform area-detector
scaling and absorption corrections. The geometrical aspects
of the structures were analyzed using the PLATON program.22
1300 w, 1280 m, 1160 w, 1120 m, 1080 m, 1040 w, 980 m, 940
1
m, 880 w, 820 m, 780 m, 680 w, 620 w, 600 w cm-1
.
H NMR
(C6D6): δ 1.21 (t, 6H, Et2O), 1.31 (vb, 36H CH3(tBu), 3.35 (q,
4H, Et2O). 13C NMR (C6D6): δ 30.86 (vb, 12 C, CH3(tBu)). Anal.
Calcd for C40H48N2Ge×(C4H10O) (703.51): C, 75.12; H, 8.31;
Ge, 10.32. Found: C, 75.00; H, 8.21; Ge, 10.18.
Ack n ow led gm en t. This work was supported by the
Russian Foundation for Basic Research (Grant No. 03-
03-32246), the Russian Science Support Foundation
(I.L.F.), and the Fonds der Chemischen Industrie. The
authors thank Dr. Yu. A. Kurskii for recording the NMR
spectra.
Syn th esis of (bp h -BIAN)Ge (3). To a solution of (bph-
12
BIAN)Mg(THF)n in THF (freshly prepared from dph-BIAN
(0.48 g, 1.00 mmol) and activated magnesium) was added
GeCl2(dioxane) (0.23 g, 1.00 mmol). The color of the solution
quickly turned from emerald-green to red-brown. When the
change in color was finished, the solvent was removed in a
vacuum and benzene (30 mL) was added to the remaining
solid. The suspension formed was filtered to separate residual
MgCl2. Evaporation of the solvent from the solution and
crystallization of the crude product from THF at room tem-
perature afforded 3 (0.32 g, 58%) as deep red crystals. Mp >
170 °C (dec). IR (Nujol): 1600 w, 1570 w, 1560 w, 1310 w,
1270 m, 1150 m, 1070 w, 1050 w, 1005 m, 970 w, 950 m, 910
Su p p or tin g In for m a tion Ava ila ble: Full details of the
X-ray structural analyses of compounds 1-3, including com-
plete tables of crystal data, atomic coordinates, bond lengths
and angles, and positional and anisotropic thermal param-
eters. This material is available free of charge via the Internet
at http://pubs.acs.org.
m, 815 m, 770 s, 750 s, 700 s, 620 w, 550 m cm-1 1H NMR
.
OM0497846
(C6D6): δ 7.60-6.95 (m, 24H). 13C NMR (C6D6): δ 119.37,
125.88, 126.12, 127.19, 127.45, 127.51, 127.59, 127.95, 127.96,
128.41, 128.63, 129.04, 129.36, 129.65, 130.42, 131.67, 136.40.
Anal. Calcd for C36H24N2Ge (557.16): C, 77.60; H, 4.34; Ge,
13.03. Found: C, 75.22; H, 4.56; Ge, 14.11.
(19) Sheldrick, G. M. SHELXS-97 Program for the Solution of
Crystal Structures; Universita¨t Go¨ttingen: Go¨ttingen, Germany, 1990.
(20) Sheldrick, G. M. SHELXL-97 Program for the Refinement of
Crystal Structures; Universita¨t Go¨ttingen: Go¨ttingen, Germany, 1997.
(21) Sheldrick, G. M. SADABS Program for Empirical Absorption
Correction of Area Detector Data; Universita¨t Go¨ttingen: Go¨ttingen,
Germany, 1996.
X-r a y Cr ysta l Str u ctu r e Deter m in a tion of Com p ou n d s
1-3. The data were collected on a SMART CCD diffractometer
(T ) 173 K, graphite-monochromated Mo KR radiation, ω-scan
technique, λ ) 0.71073 Å). The structures were solved by direct
(22) Spek, A. L. PLATON A Multipurpose Crystallographic Tool;
Utrecht University: Utrecht, Holland, 2000.