Synthesis and structures of aryloxo- and binaphthoxogermanium(IV) alkyl iodide complexes

Article abstract of DOI:10.1016/j.ica.2010.06.060

The germanium(II) aryloxide complexes (S)-[Ge{O₂C ₂₀H₁₀-(SiMe₂Ph)₂-3,3′}{NH ₃}] (1) and [Ge(OC₆H₃Ph₂-2,6) ₂] (2) react with either Bu^t

Full text of DOI:10.1016/j.ica.2010.06.060

Inorganica Chimica Acta 364 (2010) 89–95
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Inorganica Chimica Acta
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Synthesis and structures of aryloxo- and binaphthoxogermanium(IV)
alkyl iodide complexes
Anthony E. Wetherby Jr. a, Christian R. Samanamu a, Aaron C. Schrick a, Antonio DiPasquale b,
James A. Golen c, Arnold L. Rheingold b, Charles S. Weinert a,
*
a Department of Chemistry, Oklahoma State University, Stillwater, OK 74078, USA
b Department of Chemistry and Biochemistry, University of California–San Diego, La Jolla, CA 92093-0303, USA
c Department of Chemistry and Biochemistry, University of Massachusetts Dartmouth, 285 Old Westport Road, North Dartmouth, MA 02747-2300, USA
a r t i c l e i n f o
a b s t r a c t
The germanium(II) aryloxide complexes (S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{NH3}] (1) and [Ge(OC6H3Ph2-
2,6)2] (2) react with either ButI or MeI to yield the corresponding germanium(IV) compounds
(S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{But}{I}] (3), (S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{Me}{I}] (4), [Ge(OC6H3-
Ph2-2,6)2(But)(I)] (5), and [Ge(OC6H3Ph2-2,6)2(Me)(I)] (6). Compound 6 reacts with 2,6-diphenylphenol
to yield [Ge(OC6H3Ph2-2,6)3(Me)] (7), while 3–5 do not. The X-ray crystal structures of 3–5 and 7 were
determined, and 3–5 represent the first structurally characterized germanium(IV) species having germa-
nium bound to both oxygen and iodine.
Article history:
Available online 6 July 2010
Dedicated to Arnold L. Rheingold.
Keywords:
Germanium iodide complexes
Germylenes
Ó 2010 Elsevier B.V. All rights reserved.
Aryloxides
X-ray crystal structures
Binaphthoxides
1. Introduction
containing a germanium–iodine bond are rare. A search of the
CCDC database in April 2010 provided data for only 48 such species
Germanium aryloxides are an interesting class of compounds
that exhibit a diverse array of possible structures [1–36], and have
also recently been shown to serve as well-defined precursors for
the preparation of germanium(0) nanomaterials. In particular,
the morphology of the nanomaterials obtained has been shown
to depend on the substituent pattern of the ligands in the precur-
sors that contain germanium in either the divalent or tetravalent
oxidation state [2,8]. Germanium aryloxides contain germanium
attached to one or more phenolic oxygen atom and the aromatic
rings can have varying substitution patterns at the ortho-, meta-,
and/or para-positions. Both monomeric and dimeric complexes
containing simple aryloxide ligands are known [2,8,33], and some
germanium aryloxides containing calix[n]arene [10–12,19,34,35]
or binaphthoxide ligands [31,36], as well as cluster-type materials
[9], have also been reported.
[37–71]. Furthermore, the only compound containing germanium
bound to both oxygen and iodine was the acetylacetonate complex
(Acac)GeI [48], and no examples of germanium(IV)-containing spe-
cies have been reported.
We have prepared and structurally characterized the germa-
nium(IV) binaphthoxide compounds (S)-[Ge{O2C20H10-(SiMe2Ph)2-
3,30}{R}{I}] (R = But or Me) and the aryloxide [Ge(OC6H3Ph2-2,6)2-
(But)(I)], each of which has a Ge–I bond. We have also prepared
[Ge(OC6H3Ph2-2,6)2(Me)(I)], that was converted to the tri(aryloxide)
complex [Ge(OC6H3Ph2-2,6)3(Me)] upon reaction of the iodo
compound with 2,6-diphenylphenol. The ligands in the two bina-
phthoxide complexes are chelating and each contain a GeO2C4
seven-membered ring. The size of the organic substituent R has a
measurable effect on the size of the chiral pocket in these ligands,
and the aryloxide species [Ge(OC6H3Ph2-2,6)2(R)(I)] (R = But or Me)
exhibit different reactivity toward 2,6-diphenylphenol due to the
steric attributes of the organic substituent at germanium.
The monomeric germanium(II) aryloxide [Ge(OC6HPh4-
2,3,5,6)2] has been shown to yield the germanium(IV) aryloxide
complex [Ge(OC6HPh4-2,3,5,6)2(Me)(I)] via the oxidative addition
of the germanium(II) center into the C–I bond of methyl iodide
[33]. However, the X-ray crystal structure of this compound was
not obtained, and crystallographically characterized compounds
2. Results and discussion
The germanium(II) aryloxides (S)-[Ge{O2C20H10-(SiMe2Ph)2-
3,30}{NH3}] (1) [36] and [Ge(OC6H3Ph2-2,6)2] (2) [33] were synthe-
sized from Ge[N(SiMe3)2]2 and (HO)2C20H10-(SiMe2Ph)2-3,30 or
HOC6H3Ph2-2,6 (respectively). Compound 1 was converted to the
* Corresponding author.
E-mail address: weinert@chem.okstate.edu (C.S. Weinert).
0020-1693/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2010.06.060

90
A.E. Wetherby Jr. et al. / Inorganica Chimica Acta 364 (2010) 89–95
germanium(IV) binaphthoxide derivatives (S)-[Ge{O2C20H10
-
(SiMe2Ph)2-3,30}{But}{I}] (3) and (S)-[Ge{O2C20H10-(SiMe2Ph)2-
3,30}{Me}{I}] (4) in yields of 85% and 86% via insertion of the ger-
mylene 1 into the C–I bond of the corresponding alkyl iodide
(Scheme 1), which also involves liberation of the coordinated
ammonia molecule from 1.
The conversion of 1 to 3 and 4 is evident in the 1H NMR spec-
trum of the products. The spectrum of 1 exhibits a singlet for the
4,40-protons at d 8.18 ppm, indicating that they are magnetically
equivalent, and two closely spaced resonances for the methyl pro-
tons of the 3,30-SiMe2Ph groups at d 0.75 and 0.68 ppm were also
observed [36]. In the 1H NMR spectra of both 3 and 4 two reso-
nances at d 8.16 and 8.10 ppm for 3 and d 8.20 and 8.13 for 4 were
observed for the 4,40-protons. This indicates that the two 4,40-pro-
tons are no longer magnetically equivalent in 3 and 4 due to the
absence of a C2-axis in these compounds as a result of the attach-
ment of an organic substituent and an iodine atom to the germa-
nium center. Similarly, a singlet was observed for each of the
four methyl groups of the –SiMe2Ph substituents in the 1H NMR
spectra of 3 and 4. For compound 3 these peaks appear at d 0.88,
0.84, 0.80, and 0.66 ppm, while for 4 the resonances were observed
at d 0.82, 0.79, 0.71, and 0.63 ppm. A singlet corresponding to the
protons of the tert-butyl group of 3 was observed at d 0.70 ppm,
and the methyl group in 4 results in the appearance of an upfield
singlet at d 0.12 ppm.
Compounds 3 and 4 are sparingly soluble in hydrocarbon sol-
vents. However, X-ray quality crystals of 3 and 4 were obtained
by dissolving the compound in an aliquot of hot benzene that
was slowly cooled to room temperature, and ORTEP diagrams of
3 and 4 are shown in Figs. 1 and 2 while and selected bond dis-
tances and angles are collected in Tables 1 and 2 (respectively).
The germanium centers in the starting material 1 and the products
3 and 4 are incorporated into a seven-membered GeO2C4 ring that
includes the interannular C–C bond of the binaphthoxide ligand.
The GeO2C4 ring in the tert-butyl substituted species 3 has Ge–O
bond distances that differ from one another in length by
0.017(3) Å and have an average value of 1.789(3) Å. The Ge–O bond
lengths in the methyl-substituted derivative 4 are shorter than
those in 3 and have an average value of 1.734(4) Å, and they also
differ significantly from one another by 0.12(4) Å. The Ge–O bond
distances in the germylene 1 have an average value of 1.875(3) Å,
and the shorter Ge–O bond lengths in both 3 and 4 are a result
of the higher oxidation state of germanium in these two com-
plexes. The Ge–O bond distances in 3 and 4 are similar to other
germanium(IV) aryloxides, including that in the chelate complexe
[{2,2-CH(CH3)2(CH2But)}2C6H2O2]Ge(CH3)2 (1.770(2) Å), [20] which
contains a seven-membered GeO2C4 ring.
Fig. 1. ORTEP diagram of (S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{But}{I}] (3). Thermal
ellipsoids are drawn at 50% probability.
The Ge–C bond distance in 3 is 1.972(5) Å and is typical for a
germanium–carbon single bond, and the Ge–I bond length that
measures 2.5141(7) Å is similar to the average Ge–I bond lengths
in the organogermanium iodides (C5Me5)GeI3, (C6Cl5)2GeI2,
[(2-MeO–5-ButC6H3)3C]GeI3, and MeGeI3 which are 2.5335(9) Å
[37], 2.509(2) Å [61], 2.5180(8) Å [68], and 2.498(2) Å [38] (respec-
Fig. 2. ORTEP diagram of (S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{Me}{I}] (4). Thermal
ellipsoids are drawn at 50% probability.
tively). The only crystallographically characterized complex
containing germanium bound to both oxygen and iodine is (acac)-
GeI (acac = acetylacetonato), which has a Ge–I bond length of
2.7360(3) Å [48]. However, this species contains a divalent germa-
nium atom and therefore would be expected to have a longer Ge–I
bond than 3.
Scheme 1.

A.E. Wetherby Jr. et al. / Inorganica Chimica Acta 364 (2010) 89–95
91
Table 1
109.0(2)° while the O(1)–Ge(1)–I(1) and O(2)–Ge(1)–I(1) bond an-
gles are 113.9(1) and 101.5(1)°. The O(1)–Ge(1)–C(1), O(2)–Ge(1)–
C(1) and I(1)–Ge(1)–C(1) bond angles each deviate from the ideal-
ized tetrahedral value, and measure 96.1(1)°, 121.4(1)°, and
115.32(4)° (respectively).
Selected bond distances (Å) and angles (°) for
(S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{But}{I}] (3).
Ge(1)–O(1)
Ge(1)–O(2)
Ge(1)–I(1)
Ge(1)–C(37)
O(1)–C(2)
O(2)–C(12)
C(1)–C(11)
C(3)–Si(1)
C(13)–Si(2)
O(1)–Ge(1)–O(2)
O(1)–Ge(1)–I(1)
O(1)–Ge(1)–C(37)
O(2)–Ge(1)–I(1)
O(2)–Ge(1)–C(37)
I(1)–Ge(1)–C(37)
1.780(3)
1.797(3)
2.5141(7)
1.972(5)
1.377(5)
1.383(4)
1.484(6)
1.886(4)
1.879(4)
103.7(1)
111.1(1)
103.8(2)
99.38(9)
121.1(2)
117.2(1)
The dihedral angle between the two naphthalene rings is 64.78°
in 4 while that in the tert-butyl substituted compound 3 measures
65.97°. These values can be compared with that in the germa-
nium(II) complex 1 which is 70.14° [36]. The trend in the acuteness
of the dihedral angles in 1, 3, and 4 correlates with the Ge–O bond
lengths in these three compounds, which average 1.875(3) [36],
1.789(3), and 1.734(4) Å (respectively). Thus, the steric attributes
of the substituents at germanium affects the Ge–O bond distances,
which in turn affects the dihedral angle between the naphthyl
rings. The lengths of the interannular C–C bonds in these com-
pounds also correlate with the dihedral angles. Compound 4 which
has the most acute dihedral angle has an C–C bond distance of
1.486(7) Å, while 1 has the most obtuse dihedral angle and has a
C–C bond length of 1.380(5) Å. The C–C bond distance in 3 is
1.383(5) Å, which is intermediate between those of 1 and 4.
Table 2
Selected bond distances (Å) and angles (°) for
(S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{Me}{I}] (4).
Ge(1)–O(1)
Ge(1)–O(2)
Ge(1)–I(1)
Ge(1)–C(1)
O(1)–C(2)
O(2)–C(21)
C(11)–C(12)
C(3)–Si(1)
C(20)–Si(2)
O(1)–Ge(1)–O(2)
O(1)–Ge(1)–I(1)
O(1)–Ge(1)–C(1)
O(2)–Ge(1)–I(1)
O(2)–Ge(1)–C(1)
I(1)–Ge(1)–C(1)
1.674(3)
1.794(4)
2.508(1)
2.351(1)
1.280(5)
1.458(7)
1.486(7)
1.889(5)
1.799(5)
109.0(2)
113.9(1)
96.1(1)
101.5(1)
121.4(1)
115.32(4)
Scheme 2.
The germanium atom in 3 is present in a pseudo-tetrahedral
environment which is distorted due to the presence of the
sterically encumbering tert-butyl group. The O(1)–Ge(1)–O(2)
and O(1)–Ge(1)–C(37) bond angles are 103.7(1)° and 103.8(1)°
(respectively) and approach the idealized tetrahedral value of
104.5°. However, the O(2)–Ge(1)–C(37) bond angle measures
121.1(2)° and is significantly distorted due to the steric interaction
of the –SiMe2Ph group attached to C(13) with the tert-butyl substi-
tuent at germanium. The disposition of the tert-butyl group rela-
tive to the oxygen atoms in 3 due to its steric interactions with
the 3,30-substituents also results in a distortion of the O–Ge–I bond
angles from the ideal value, as the O(1)–Ge(1)–I(1) bond angle
measures 111.1(1)° while the O(2)–Ge(1)–I(1) bond angle is
99.38(9)°.
The carbon atom of the methyl group and the iodine atom in 4
are disordered with one another, with relative occupancies for the
carbon atoms of 0.623(2) and 0.377(2) over the two sites. The OR-
TEP diagram shown in Fig. 2 is drawn with the iodine atom located
on the more distant site from the germanium atom. The Ge–I
distance in 4 measures 2.508(1) Å, and is consistent with the ger-
manium–iodine distances in 28 other crystallographically charac-
terized compounds containing a Ge–I bond [37–71]. However,
the germanium–carbon bond distance in 4 is 2.351(1) Å, which is
elongated relative to the usual Ge–C bond distance of ca. 1.94 Å
[72] as a result of the dominance of the heavy iodine atom versus
the smaller carbon. The actual Ge–C bond distance in 4 is likely in
the range of 1.94–1.97 Å. As found for the tert-butyl substituted
species 3, the germanium atom in 4 is also in a distorted tetrahe-
dral environment. The O(1)–Ge(1)–O(2) bond angle measures
Fig. 3. ORTEP diagram of [Ge(OC6H3Ph2-2,6)2(But) (I)] (5). Thermal ellipsoids are
drawn at 50% probability.

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A.E. Wetherby Jr. et al. / Inorganica Chimica Acta 364 (2010) 89–95
Table 3
Selected bond distances (Å) and angles (°) for [Ge(OC6H3Ph2-2,6)2(But) (I)] (5) and
[Ge(OC6H3Ph2-2,6)3(Me)]ꢁC6H6 (7ꢁC6H6).
5
7ꢁC6H6
Ge(1)–O(1)
Ge(1)–I(1)
Ge(1)–C(19)
O(1)–C(1)
O(1)–Ge(1)–O(10)
O(1)–Ge(1)–I(1)
O(1)–Ge(1)–C(19)
I(1)–Ge(1)–C(19)
1.763(4)
2.641(1)
1.92(1)
1.392(7)
96.2(3)
107.8(1)
128.5(3)
103.0(3)
Ge(1)–O(1)
Ge(1)–C(19)
O(1)–C(1)
O(1)–Ge(1)–O(10)
O(1)–Ge(1)–C(19)
1.771(2)
1.914(6)
1.374(4)
100.8(1)
117.15(8)
The reaction of the 2,6-diphenylphenoxy-substituted germyl-
ene [Ge(OC6H3Ph2-2,6)2] (2) with ButI generates the germa-
nium(IV) species [Ge(OC6H3Ph2-2,6)2(But)(I)] (5) (Scheme 2). The
1H NMR spectrum of 5 contains a resonance at d 0.32 ppm corre-
sponding to the nine methyl protons of the tert-butyl group. Crys-
tals of 5 suitable for X-ray diffraction were obtained by the slow
evaporation of a benzene solution of this material, and an ORTEP
diagram of 5 is shown in Fig. 3 and selected bond distances and an-
gles are collected in Table 3. The iodine atom and the carbon atoms
of the tert-butyl group are disordered with one another and were
refined with occupancies of 0.5. As a result, there is a crystallo-
graphic C2-axis in 5 that renders both oxygen atoms equivalent.
The Ge–O bond distance is 1.763(4) Å and is similar to those in 3
and 4, while the Ge–I bond length is 2.641(1) Å and is consistent
with other compounds containing a germanium–iodine bond
[37–71]. Despite the disorder in 5, the Ge–C bond length is normal
Fig. 4. ORTEP diagram of [Ge(OC6H3Ph2-2,6)3(Me)]ꢁC6H6 (7ꢁC6H6). Thermal ellip-
soids are drawn at 50% probability.
covered serendipitously upon reaction of 6 with adventitious 2,6-
diphenylphenol formed via hydrolysis of 6 by water present in
the iodomethane reagent. The conversion of 6 to 7 indicates that
the iodide ligand in 6 is sufficiently labile to react with the acidic
phenolic proton of 2,6-diphenylphenol, and 7 was subsequently
prepared directly by the reaction of 6 with one equiv. of 2,6-diphe-
nylphenol in 77% yield. Compound 7 is virtually insoluble in hydro-
carbon solvents, but a 1H NMR spectrum of 7 was obtained and
exhibits a resonance for the methyl group at d – 0.12 ppm that is
shifted downfield from that for the methyl protons in 6 due to
the presence of the additional Ge–O bond.
X-ray quality crystals of 7 were obtained from the slow cooling
of a hot dilute benzene solution of 7, and an ORTEP diagram of 7 is
shown in Fig. 4. There is a C3-axis present in 7 located along the
Ge(1)–C(19) bond that renders all three aryloxo ligands equivalent.
The three Ge–O bonds in 7 measure 1.771(2) Å, which is similar to
the Ge–O bond distances in 3–5, while the Ge(1)–C(19) bond
length is 1.914(6) Å. The three O–Ge–O bond angles are 100.8(1)°
while the O(1)–Ge(1)–C(19) bond angles each measure 117.15(8)°.
The ortho-phenyl rings in 7 are each rotated about the C–C bonds
to C(2) and C(6) relative to the plane of the phenolic phenyl ring
due to steric effects arising from the presence of three bulky 2,6-
diphenylphenolate ligands at the germanium center. The angle
about the C(2)–C(13) bond is 48.5(1)° and the angle about the
C(6)–C(7) bond is 42.0(1)°, and the 2,6-diphenylphenolate ligands
interlock in a gear-like fashion in 7.
for
a germanium(IV)–oxygen bond distance and measures
1.918(1) Å. The O(1)–Ge(1)–O(10) bond angle is extremely acute
and measures 96.2(3)°, the O(1)–Ge(1)–I(1) bond angle is
107.8(1)° and approaches the idealized tetrahedral angle, and the
C(19)–Ge(1)–I(1) bond angle measures 103.0(3)°.
The reaction of
2 with iodomethane yields the complex
[Ge(OC6H3Ph2-2,6)2(Me)(I)] (6) in 86% yield (Scheme 2). In order
to successfully prepare 6, the iodomethane was meticulously dried
over magnesium sulfate and activated molecular sieves immedi-
ately before use to prevent hydrolysis and subsequent reaction of
6 with the liberated 2,6-diphenylphenol (vide infra). The 1H NMR
spectrum of 6 contains a resonance at d ꢀ0.49 ppm corresponding
to the protons of the methyl group. Despite several attempts, we
were not able to obtain X-ray quality crystals of this material,
but the composition of 6 was further confirmed by elemental anal-
ysis and mass spectrometry. The mass spectrum of 6 exhibits a
peak at m/z = 706 amu with the expected isotope pattern, as well
as peaks corresponding to fragmentation of the molecule at
m/z = 579 amu (M+ꢀI) and m/z = 461 amu (M+ꢀOC6H3Ph2).
Compound 6 can be converted to the tri(aryloxo)-species
[Ge(OC6H3Ph2-2,6)3(Me)] (7) upon reaction with additional 2,6-
diphenylphenol (Scheme 3). The formation of 7 was initially dis-
Curiously, treatment of 5 with an additional equivalent of 2,6-
diphenylphenol did not provide the tri(aryloxo)-compound
[Ge(OC6H3Ph2-2,6)3(But)]. Although the iodide ligand in 5 would
also be expected to be reactive toward protonolysis, no evidence
for the formation of [Ge(OC6H3Ph2-2,6)3(But)] was found even if
the reaction mixture was heated for 7 days at 85 °C. Therefore,
the formation of 7 from 6 appears to be possible due to the pres-
ence of the less sterically encumbering methyl group in 6 versus
the large tert-butyl group in 5. Similarly, compounds 3 and 4 were
not found to react with 2,6-diphenylphenol which is likely a result
of the sterically congested environment at the germanium atoms
in these species arising from the bulky 3,30-SiMe2Ph substituents.
Scheme 3.

A.E. Wetherby Jr. et al. / Inorganica Chimica Acta 364 (2010) 89–95
93
procedures. The reagents 2,6-diphenylphenol, iodomethane and 2-
iodo-2-methylpropane (ButI) were purchased from Aldrich and the
iodo compounds were dried over anhydrous MgSO4 followed by
activated molecular sieves immediately prior to use. Proton NMR
spectra were run at 25 °C in benzene-d6 on a Varian Gemini 2000
spectrometer at 300 MHz and were referenced to residual protio
solvent. Carbon-13 NMR spectra were not acquired due to the
low solubility of these compounds in benzene-d6 and their insta-
bility in more polar solvents including chloroform-d and acetoni-
trile-d3. Mass spectra were acquired via direct injection using a
Shimadzu LCMS-2010 equipped with an ACPI ionization source.
Elemental analyses were conducted by Desert Analytics (Tucson,
AZ).
3. Conclusions
The germylenes (S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{NH3}] (1)
and [Ge(OC6H3Ph2-2,6)2] (2) have been shown to react with iodo-
methane and 2-iodo-2-methylpropane (ButI) to yield the germa-
nium(IV) complexes (S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{But}{I}]
(3), (S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{Me}{I}] (4), [Ge(OC6H3Ph2-
2,6)2(But)(I)] (5), and [Ge(OC6H3Ph2-2,6)2(Me)(I)] (6). The X-ray
crystal structures of 3–5 were determined and compounds 3 and
4 were shown to be chelates that each contain a seven-membered
GeO2C4 ring, and the size of the organic group attached to the ger-
manium atom in 3 and 4 affects the size of the chiral pocket in the
attached binaphthoxide ligand. The 2,6-diphenylphenolate species
5 was crystallographically characterized, and compound 6 was
found to react with one equiv. of 2,6-diphenylphenol to yield the
tri(aryloxo)-species [Ge(OC6H3Ph2-2,6)3(Me)] (7). However, similar
reactivity was not observed for compounds 3–5. The structure of 7
contains a C3-axis of rotation about the central Ge–CH3 bond and
the three aryloxide ligands in 7 are arranged in an interlocking
gear-like fashion about the central germanium atom.
4.2. Synthesis of 3
To a solution of 1 (0.200 g, 0.312 mmol) in benzene (20 mL) was
added a solution of ButI (0.070 g, 0.380 mmol) in benzene (5 mL).
The reaction mixture was stirred at reflux for 12 h and the volatiles
were removed in vacuo to yield 3 (0.215 g, 85%) as white crystals.
1H NMR: d 8.16 (s, 1H, 4,40-H), 8.10 (s, 1H, 4,40-H), 7.70–7.52 (m,
8H, aromatics), 7.29–7.25 (m, 4H, aromatics), 7.12–7.04 (m, 8H,
aromatics), 6.99–6.84 (m, 2H, aromatics), 0.88 (s, 3H, Si(CH3)2Ph),
0.84 (s, 3H, Si(CH3)2Ph), 0.80 (s, 3H, Si(CH3)2Ph), 0.70 (s, 9H,
GeC(CH3)3), 0.67 (s, 3H, Si(CH3)2Ph), ppm. Anal. Calcd. for
4. Experimental
4.1. General considerations
C40H41GeIO2Si2: C, 59.35; H, 5.11. Found: C, 58.98; H, 5.21%.
All manipulations were carried out using standard Schlenk,
syringe, and glovebox techniques [73]. Solvents were purified
using a Glass Contour solvent purification system. The starting
materials (S)-[Ge{O2C20H10-(SiMe2Ph)2-3,30}{NH3}] (1) [36] and
[Ge(OC6H3Ph2-2,6)2] (2) [33] were prepared according to published
4.3. Synthesis of 4
To a solution of 1 (0.145 g, 0.226 mmol) in benzene (20 mL) was
added neat iodomethane (0.160 g, 1.13 mmol). The reaction
Table 4
Crystallographic data for compounds 3–5 and 7ꢁC6H6.
3
4
5
7ꢁC6H6
Empirical formula
Formula weight (g/mol)
T (K)
C40H41GeIO2Si2
809.40
209(2)
C37H35GeIO2Si2
767.32
100(2)
C40H35GeIO2
747.17
100(2)
C61H46GeO3
899.57
100(2)
Wavelength (Å)
Crystal system
Space group
a (Å)
b (Å)
c (Å)
0.71073 (Mo K
orthorhombic
P212121
7.470(3)
12.560(4)
38.94(1)
90
a
)
0.71073 (Mo K
monoclinic
P21
9.052(1)
10.631(2)
17.652(3)
90
a
)
0.71073 (Mo K
monoclinic
C2/c
14.466(4)
13.592(4)
17.452(6)
90
a
)
0.71073 (Mo K
rhombohedral
R3
15.8640(5)
15.8640(5)
15.736(1)
90
a)
a
(°)
b (°)
90
90
3653(2)
4
1.472
95.623(2)
90
1690.6(5)
2
1.507
1.921
100.712(7)
90
3372(2)
4
1.472
1.857
90
120
3429.6(3)
3
1.307
c
(°)
V (Å3)
Z
Density (g/cm3)
Absorption coefficient (mmꢀ1
F (0 0 0)
)
1.783
1640
0.718
1404
772.1
1504
Crystal size (mm)
h Range for data collection (°)
0.33 ꢂ 0.08 ꢂ 0.05
0.20 ꢂ 0.15 ꢂ 0.15
0.36 ꢂ 0.31 ꢂ 0.31
0.44 ꢂ 0.36 ꢂ 0.30
1.70–28.21
2.24–28.28
2.07–28.18
1.97–25.32
Index ranges
ꢀ5 6 h 6 9
ꢀ11 6 h 6 11
ꢀ13 6 k 6 13
ꢀ23 6 l 6 22
14 200
ꢀ18 6 h 6 19
ꢀ13 6 k 6 17
ꢀ22 6 l 6 22
14 144
ꢀ18 6 h 6 18
ꢀ19 6 k 6 19
ꢀ18 6 l 6 16
8305
ꢀ16 6 k 6 16
ꢀ41 6 l 6 49
18 942
Reflections collected
Independent reflections
Completeness to h = 25.00°
Absorption correction
Maximum and minimum
transmission
8464 (Rint = 0.0414)
99.9%
7263 (Rint = 0.0803)
99.8%
semi-empirical from equivalents multi-scan (SADABS
3800 (Rint = 0.0479)
97.3%
2492 (Rint = 0.0293)
100.0%
multi-scan (SADABS
)
)
multi-scan (SADABS
0.8134–0.7429
)
0.9162 and 0.5908
0.7615 and 0.6999 0.5967 and 0.5544
Refinement method
full-matrix least-squares on F2 full-matrix least-squares on F2
full-matrix least-squares on F2 full-matrix least-squares on F2
Data/restraints/parameters
8464/0/415
1.006
7263/1/395
1.121
3800/0/213
1.187
2492/1/199
1.052
Goodness-of-fit (GOF) on F2
Final R indices (I > 2
r
(I))
R1 = 0.0453
wR2 = 0.0746
R1 = 0.0604
wR2 = 0.0799
0.991 and ꢀ0.417
R1 = 0.0545
wR2 = 0.1290
R1 = 0.0594
wR2 = 0.1314
1.338 and ꢀ0.906
R1 = 0.0697
wR2 = 0.1557
R1 = 0.0892
wR2 = 0.1630
0.677 and ꢀ1.363
R1 = 0.0407
wR2 = 0.1090
R1 = 0.0415
wR2 = 0.1099
1.189 and ꢀ0.299
R indices (all data)
Largest difference peak
and hole (e Åꢀ3
)

94
A.E. Wetherby Jr. et al. / Inorganica Chimica Acta 364 (2010) 89–95
mixture was stirred at reflux for 18 h and the volatiles were re-
moved in vacuo to yield 4 (0.148 g, 86%) as white crystals. 1H
NMR: d 8.20 (s, 1H, 4,40-H), 8.13 (s, 1H, 4,40-H), 7.73–7.55 (m, 8H,
aromatics), 7.24–7.00 (m, 12H, aromatics), 6.86–6.78 (m, 2H, aro-
matics), 0.82 (s, 3H, Si(CH3)2Ph), 0.79 (s, 3H, Si(CH3)2Ph), 0.71 (s,
3H, Si(CH3)2Ph), 0.63 (s, 3H, Si(CH3)2Ph), 0.12 (s, 3H, GeCH3) ppm.
Anal. Calcd. for C37H35GeIO2Si2: C, 57.91; H, 4.60. Found: C,
57.64; H, 4.45%.
Appendix A. Supplementary material
CCDC 774956, 774957, 774958, and 774959 contain the supple-
mentary crystallographic data for 3, 4, 5, and 7. These data can be
obtained free of charge from The Cambridge Crystallographic Data
Centre via www.ccdc.cam.ac.uk/data_request/cif. Supplementary
data associated with this article can be found, in the online version,
at doi:10.1016/j.ica.2010.06.060.
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