Synthesis, structural characterization, and reactivity of (8-methoxynaphthyl)hydridogermanium triflates and iodides

Article abstract of DOI:10.1021/om970963f

New 8-(methoxynaphthyl)hydridogermanium triflates and iodides were synthesized by treatment of the corresponding germanes with trifluoromethanesulfonic acid or I₂. Their characterization by ¹H and ¹³C NMR and IR spectroscopy is reported. In the solid state, bis(8-methoxynaphthyl)hydridogermanium triflate (6) exhibits a 5-coordinate germanium atom weakly linked to the triflate anion. The germyl iodide rapidly gives the germoxolene with loss of MeI when it is heated in CH₃CN. With H₂O, amine, and DMSO, the germyl triflates react quantitatively to form new complexes which can be isolated and characterized. The X-ray crystal structure of the hydrate of bis(8-methoxynaphthyl)hydridogermanium triflate (11) shows the predominant formation of a hydrated germyl cation. Several tentative approaches to prepare germanols failed and always gave stable germoxanes instead.

Full text of DOI:10.1021/om970963f

2222
Organometallics 1998, 17, 2222-2227
Syn th esis, Str u ctu r a l Ch a r a cter iza tion , a n d Rea ctivity of
(8-Meth oxyn a p h th yl)h yd r id oger m a n iu m Tr ifla tes a n d
Iod id es
F. Cosledan, A. Castel, P. Rivie`re,* and J . Satge´
Laboratoire “He´te´rochimie Fondamentale et Applique´e”, Universite´ Paul Sabatier,
118, Route de Narbonne, 31062 Toulouse Ce´dex 04, France
M. Veith and V. Huch
Institute of Inorganic Chemistry, University of Saarland, P.O. Box 151150,
D-66041 Saarbru¨cken, Germany
Received November 4, 1997
New 8-(methoxynaphthyl)hydridogermanium triflates and iodides were synthesized by
treatment of the corresponding germanes with trifluoromethanesulfonic acid or I2. Their
1
characterization by H and 13C NMR and IR spectroscopy is reported. In the solid state,
bis(8-methoxynaphthyl)hydridogermanium triflate (6) exhibits a 5-coordinate germanium
atom weakly linked to the triflate anion. The germyl iodide rapidly gives the germoxolene
with loss of MeI when it is heated in CH3CN. With H2O, amine, and DMSO, the germyl
triflates react quantitatively to form new complexes which can be isolated and characterized.
The X-ray crystal structure of the hydrate of bis(8-methoxynaphthyl)hydridogermanium
triflate (11) shows the predominant formation of a hydrated germyl cation. Several tentative
approaches to prepare germanols failed and always gave stable germoxanes instead.
In tr od u ction
corresponding organolithium. Their reduction by Li-
AlH4 gave the expected organogermanes 1-3 (eq 1).
We have recently described the stabilization of orga-
nogermyllithiums1 by the 8-methoxynaphthyl group and
have shown a weak coordinative interaction between
germanium and methoxy oxygen atoms giving a ger-
manium(V) center in the starting organogermanes.
Moreover, the stabilizing effect of O-chelation has been
illustrated in the case of 2-oxo-1-hexahydroazepinyl-
methyl ligands.2 X-ray diffraction analysis showed a
possible coordinative interaction between the germa-
nium center and the oxygen of the carbonyl group when
the metal was surrounded by halogen atoms. The
authors suggested the possibility of ionic dissociation
of these compounds in sufficiently polar solvents. We
herein describe the synthesis and reactivity of various
(8-methoxynaphthyl)germanium iodides and triflates.
Their behavior as possible germyl cations3 will be
discussed on the basis of an X-ray structure and
spectroscopic data.
Treatment of the (8-methoxynaphthyl)germanes 1-3
with trifluoromethanesulfonic acid in diethyl ether or
with I2 in benzene gave the corresponding germanium
triflates 4-64 and iodides 7 and 84 in good yields (eq
2). These compounds are very air-sensitive powders,
insoluble in common hydrocarbon solvents but soluble
in chlorinated solvents (CH2Cl2 and CHCl3).
The X-ray structure of the triflate 6 is shown in
Figure 1. Some of the important bond lengths and
angles are assembled in Table 1, and a summary of
crystallographic data is given in Table 2. The geometry
at germanium is very close to trigonal bipyramidal. The
two 8-methoxynaphthyl ligands and the hydrogen atom
form the central plane. The sum of the bond angles in
the equatorial plane deviates by 3.2° from the ideal
Resu lts a n d Discu ssion
The dichloroorganogermanes were prepared by an
organomagnesium route or by the direct reaction of the
(1) Castel, A.; Rivie`re, P.; Cosledan, F.; Satge´, J .; Onyszchuk, M.;
Lebuis, A. M. Organometallics 1996, 15, 4488.
(2) (a) Ovchinnikov, Yu. E.; Struchkov, Yu. T.; Baukov, Yu. I.;
Shipov, A. G.; Kramarova, E. P.; Bylikin, S. Yu. Russ. Chem. Bull.
(Engl. Transl.) 1994, 43, 1346. (b) Ovchinnikov, Yu. E.; Struchkov, Yu.
T.; Baukov, Yu. I.; Shipov, A. G.; Bylikin, S. Yu. Russ. Chem. Bull.
(Engl. Transl.) 1994, 43, 1351. (c) Ovchinnikov, Yu. E.; Struchkov, Yu.
T.; Shipov, A. G.; Smirnova, L. S.; Baukov, Yu. I.; Bylikin, S. Yu.
Mendeleev Commun. (Engl. Transl.) 1994, 178.
(3) (a) Belzner, J . Angew. Chem., Int. Ed. Engl. 1997, 36, 1277. (b)
Schleyer, P. v. R. Science 1997, 275, 39.
(4) Cosledan, F.; Castel, A.; Rivie`re, P. Main Group Met. Chem. 1997,
20, 5.
S0276-7333(97)00963-1 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 05/08/1998

Reactivity of Germanium Triflates and Iodides
Organometallics, Vol. 17, No. 11, 1998 2223
Ta ble 1. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 6
Ge-O(1)
Ge-O(2)
Ge-O(3)
Ge-H
2.357(3)
2.799(3)
1.988(3)
1.33(3)
2.46(3)
2.78(3)
C(11)-Ge
C(1)-Ge
S-O(3)
1.938(4)
1.945(4)
1.483(3)
1.406(3)
1.417(3)
1.379(6)
1.414(5)
S-O(4)
O(2)-H
S-O(5)
C(1)-C(2)
C(1)-C(10)
O(4)-H
C(11)-C(12)
C(11)-C(20)
1.369(5)
1.428(5)
C(1)-Ge-C(11)
C(1)-Ge-O(3)
C(1)-Ge-O(1)
C(11)-Ge-O(3)
C(11)-Ge-O(1)
O(3)-Ge-O(1)
112.81(15)
98.29(14)
76.84(14)
93.04(14)
90.19(14)
174.93(10)
H-Ge-C(11)
H-Ge-C(1)
127.8(12)
116.4(12)
84.9(13)
96.1(13)
118.5(4)
119.6(3)
H-Ge-O(1)
H-Ge-O(3)
C(21)-O(1)-C(9)
C(22)-O(2)-C(19)
F igu r e 1. ORTEP drawing of 6.
Ta ble 2. Su m m a r y of Cr ysta llogr a p h ic Da ta for
Com p ou n d s 6 a n d 11
6
11
empirical formula
Mr
cryst syst
space group
a/Å
C
23H23F3GeO5S
C23H21F3GeO6S
555.05
triclinic
P1h
10.286(2)
11.052(2)
12.449(2)
67.55(3)
67.69(3)
68.76(3)
1170.3(4)
2
541.06
monoclinic
P21/n
10.209(2)
17.049(3)
12.918(3)
90
95.15(3)
90
2239.3(8)
4
b/Å
c/Å
R/deg
â/deg
γ/deg
V/Å3
value of 360°. The angles C(11)-Ge-C(1) and H-Ge-
C(1) are decreased to 112.81(15)° and 116.4(12)°, whereas
H-Ge-C(11) is widened to 127.8(12)°. The two dis-
tances Ge-C(1) (1.945(4) Å) and Ge-C(11) (1.938(4) Å)
are similar and correspond to normal covalent bonds
(1.90-2.05 Å).5 The Ge-H bond (1.33(3) Å) is signifi-
cantly shorter than a Ge-H covalent bond (1.46-1.70
Å),5 even considering that the position of H in the X-ray
structure lacks precision. A similar shortening of the
Si-H bond has been observed in the case of a silylium
cation stabilized by amino groups.6 The axial positions
are occupied by one methoxy group (O(1)) and the
triflate anion (O(3)). The Ge-O(1) distance, 2.357(3)
Å, is longer than that of the Ge-O covalent bond (1.75-
1.85 Å)5 but appreciably shorter than the sum of the
van der Waals radii (3.40 Å), suggesting a coordinative
interaction between the Ge and this methoxy oxygen
atom. In contrast, the second methoxy group (O(2))
seems almost not linked to the germanium atom (Ge-
O(2) ) 2.799(3) Å); the steric hindrance of the triflate
group and the hydrogen atom on germanium probably
prevents the second complexation. Further NMR spec-
troscopic measurements may confirm the presence of a
pentacoordinated germanium atom. The Ge-O(3) (tri-
flate group) distance, 1.988(3) Å, is slightly longer than
a covalent Ge-O bond. From the same observation in
the silicon series,6,7 J utzi et al. concluded that the
lengthening of the Si-O bond, a minor one, indicates a
polar character of this bond. Similarly, we think that
the methoxy chelation of the germanium center en-
hances the polarity of the Ge-O bond.
Z
F(000)
1104
1.605
293(2)
564
1.575
293(2)
Dc/Mg m-3
T/K
cryst size/mm
θ range/deg
no. of rflns collcd
no. of indep rflns
no. of obsd rflns
GOF on F2
final R indices (I > 2σ(I)) R1 ) 0.039
R indices (all data)
wR2
0.2 × 0.12 × 0.08 0.3 × 0.2 × 0.15
1.98-24.13
11 832
3348
1.84-22.39
7545
2818
1995
1.06
R1 ) 0.059
R1 ) 0.087
0.1609
2378
0.906
R1 ) 0.061
0.0951
Ta ble 3. Kin etics P a r a m eter s for Com p ou n d s 6
a n d 8
compd
Tc (K)
kc (s-1
)
∆Gc* (kcal/mol)
6
8
223
232
239.7
308.4
10.50
10.82
exchange process at the germanium center. When the
temperature is decreased, two resolved signals of equal
intensity appear. Coalescence temperature and kinetic
parameters, estimated on the basis of the NMR mea-
surements,8 are collected in Table 3. These results
suggest that a single mechanism operates throughout
the temperature range (∼100 K) because the Eyring
plots are linear.9 Several explanations are possible: (1)
intramolecular nondissociative processes (Berry10 pseu-
dorotation for bipyramidal geometry or a Bailar11 twist
in the case of an ideal octahedral geometry) or (2) a
dissociative process (rapid interconversion of the chelat-
ing groups). In our compounds 6 and 8, the high
At room temperature, the 1H NMR spectra of com-
pounds 6 and 8 show broadened signals due to the
methoxy groups which presumably are the result of an
(8) For simple coalescence cases, the barriers determined at the
coalescence temperature by kc ) 2.2 ∆ν are reliable. The Eyring plot
of data from line-shape analysis is given in the Supporting Information.
(9) Breliere, C.; Corriu, R. J . P.; Royo, G.; Zwecker, J . Organome-
tallics 1989, 8, 1834.
(10) Corriu, R. J . P.; Young, J . C. In The Chemistry of Organic
Silicon Compounds; Patai, S., Rappoport, Z., Eds.; Wiley: Chichester,
U.K., 1989; p 1241 and references therein.
(5) Baines, K. M.; Stibbs, W. G. Coord. Chem. Rev. 1995, 145, 157.
(6) Belzner, J .; Scha¨r, D.; Kneisel, B. O.; Herbst-Irmer, R. Organo-
metallics 1995, 14, 1840.
(7) Mix, A.; Berlekamp, U. H.; Stammler, H.-G.; Neumann, B.; J utzi,
P. J . Organomet. Chem. 1996, 521, 177.
(11) Bailar, J . C. Inorg. Nucl. Chem. 1958, 6, 165.

2224 Organometallics, Vol. 17, No. 11, 1998
Cosledan et al.
Sch em e 1
Ta ble 4. Va r ia tion of δ (p p m ) of th e Ger m yl
Tr ifla tes a n d Iod id es Com p a r ed w ith Sta r tin g
Com p ou n d s
tivity of a dichloromethane solution containing bis(8-
methoxynaphthyl)hydridogermane (3) increases when
trifluoromethanesulfonic acid is added until 1 mol equiv
of reagent was added. We have previously verified that
the starting derivatives show no significant conductiv-
ity.
1H NMR
13C NMR
(CDCl3, ppm)
(CDCl3, ppm)
IR (cm-1
ν(GeH)
)
a
compd δ(GeH) ∆δ(GeH) δ(Cipso
)
∆δ(Cipso
)
These results show that compounds containing two
8-methoxynaphthyl ligands appear to be five-coordinate
with only one methoxy group bonded to germanium at
a time. The methoxy chelation of the germanium center
seems to enhance the polarity of the Ge-O (triflate)
bond so that a contact ion pair nearly is formed. This
also is supported by the possibility of nucleophilic
complexation of the germanium center in such deriva-
tives.
Indeed, the degree of complexation of silylium cations
by solvent15 was the best argument to determine the
“free” character of such species. We sought to verify if
the cationic character of our germylated derivatives
involves a positive charge on the Ge sufficiently large
to facilitate coordination of a molecule of solvent. It was
found that treatment of stoichiometric amounts of 6
with benzylamine, water, or DMSO led to quantitative
formation of the corresponding complexes 10-12, re-
spectively (Scheme 1).
4
5
6
7
8
6.69
+2.06
122.35
-5.40
-6.35
-4.98
-6.35
-1.98
2121, 2109
2151
2170
2095
2122
123.10
128.32
123.10
131.32
7.85
6.91
7.35
+2.04
+1.45
+1.54
a
Ipso C of naphthyl group.
apicophilicity12 of the oxygen atom (in methoxy or
triflate groups) compared with the carbon or hydrogen
atoms allows us to eliminate the nondissociative pro-
cesses. Moreover, the values of the energy of activation
are similar to those previously obtained by Willcott13
for a dissociative process. Thus, it is possible to explain
the nonequivalence of the methoxy groups at low
temperature in terms of their rapid interconversion
which averages the NMR signals at room temperature.
The 1H NMR Ge-H resonances in compounds 4-8
are shifted drastically to higher frequency in comparison
with the corresponding neutral precursors (∆δ ) +1.45
to +2.06) (cf. Table 4). This finding is in agreement with
the presence of deshielded hydrogen atoms, particularly
for 6 where δ ) (Ge-H) is higher than that in Cl3GeH
(7.66 ppm).14 In the IR spectra, we observed very high
values for ν(Ge-H), consistent with a positively charged
hydrogen atom. Shifts of the ipso aromatic carbon atom
resonances (cf. Table 4) toward higher field also suggest
a localization of positive charge on the germanium atom.
The ionic structure of the compound 6 in solution is
confirmed by conductivity measurements. The conduc-
Compound 10 was too unstable to allow its isolation,
1
but it was identified by H NMR. Complexes 11 and
12 were obtained as air-sensitive white powders.
Single-crystal X-ray analysis of 11 revealed the pres-
ence of a dimeric form in which O-H interactions
between the hydrogen of H2O and the oxygen atom of
the triflate anion connected the two monomers (Figure
2). Selected bond lengths and bond angles are shown
in Table 5. The most notable features are the complex-
ation of only one methoxy group to the germanium atom
and a long Ge-O(3) bond (1.951(6) Å), as had been
observed for compound 6. The germanium atom shows
(12) Corriu, R. J . P.; Kpoton, A.; Poirier, M.; Royo, G.; de Saxce´, A.;
Young, J . C. J . Organomet. Chem. 1990, 395, 1.
(13) Benin, V. A.; Martin, J . C.; Willcott, M. R. Tetrahedron Lett.
1994, 35, 2133.
(14) Rivie`re, P.; Rivie`re-Baudet, M.; Satge´, J . Comprehensive Or-
ganometallic Chemistry; Pergamon Press: Oxford, U.K., 1982; Vol. 2,
pp 399, 1995; Ibid.,Vol. 2, p 137.
(15) Arshadi, M.; J ohnels, D.; Edlund, V.; Ottosson, C. H. Cremer,
D. J . Am. Chem. Soc. 1996, 118, 5120.

Reactivity of Germanium Triflates and Iodides
Organometallics, Vol. 17, No. 11, 1998 2225
with an excess of H2O/Et3N gave the germoxanes
directly (eq 3). Thus, under the experimental conditions
F igu r e 2. ORTEP drawing of 11.
Ta ble 5. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for 11
used, the germanols appear to be too unstable to be
isolated, supporting the idea that a B type form for
compound 11 is less probable than A.
Treatment of germyl iodide 8 with NaBPh4 (eq 4) in
CH3CN does not give the expected anion exchange
product; rather, the germoxolene 9 is formed with loss
of MeI.
Ge-O(1)
Ge-O(2)
Ge-O(3)
Ge-H
2.425(5)
2.785(6)
1.951(6)
1.51(6)
2.54(5)
2.71(5)
2.60(5)
O(3)-O(4)
O(3)-O(6)
Ge-C(9)
Ge-C(20)
S-O(4)
2.624(9)
2.549(9)
1.928(8)
1.953(8)
1.425(7)
1.404(8)
1.415(8)
O(1)-H
O(2)-H
O(3)-H
S-O(5)
S-O(6)
C(9)-Ge-C(20)
C(20)-Ge-H
C(9)-Ge-H
110.4(3)
O(3)-Ge-O(1)
O(4)-O(3)-O(6)
O(3)-Ge-C(9)
O(3)-Ge-C(20)
O(2)-Ge-C(9)
C(12)-O(2)-C(22)
168.4(2)
117.4(3)
97.2(3)
102.0(3)
175.2(3)
119.0(8)
131(2)
111(2)
77(2)
71(2)
97(2)
O(1)-Ge-H
O(2)-Ge-H
O(3)-Ge-H
C(1)-O(1)-C(11)
118.4(6)
a slightly distorted trigonal bipyramidal geometry (omit-
ting the rather long Ge-O(2) distance) with the apical
sites occupied by one methoxy group and the H2O
molecule. The three S-O distances are in the same
range: 1.425(7), 1.404(9), and 1.415(8) Å, suggesting a
dissociated form consisting of the triflate anion and the
hydrated germyl cation in the solid state.
The donation of a lone electron pair of the methoxy
oxygen atom to the positive germanium center will
generate a partial positive charge on oxygen. This in
turn will result in inductive release of electron density
from the methyl group to oxygen, making the CH3
carbon atom more electrophilic and thus faciliting attack
at the methyl carbon by I-. A polar solvent (CH3CN)
will favor such a nucleophilic substitution.
1
The H NMR and IR spectra support this hypothesis.
The low-field chemical shift displacement of the GeH
resonance (7.76 ppm) and the very high value for ν(Ge-
H) (2165 cm-1) are consistent with a positive by charged
germanium center.
In the silicon series, Reed16 also proposes a predomi-
nance of silyl cation character (A) for his protonated
silanol:
Exp er im en ta l Section
Gen er a l Com m en ts. All reactions were performed under
a dry argon atmosphere using standard Schlenk techniques.
The hydrocarbon solvents were dried and distilled from sodium
under an inert atmosphere. The compounds were character-
ized by the usual analytical techniques: 1H NMR, AC 80
Bruker; 13C NMR, AC 200 and ARX 400 Bruker; IR, Perkin-
Elmer 1600 FT; mass spectra, Ribermag R 10 10 (EI or CI,
CH4) and HP 5989 A. Melting points were measured on a
Reichert microscope. Elemental analyses were performed by
the Centre de Microanalyse de l′Ecole Nationale Supe´rieure
de Chimie de Toulouse.
Compounds 2 and 3 were prepared as described in ref 1.
Syn th esis of (8-Meth oxyn a p h th yl)ger m a n e (1). A solu-
tion of (8-methoxynaphthyl)lithium17 (8.52 g, 52 mmol) in 100
mL of THF was added dropwise at 20 °C to a suspension of
54.6 mmol of MgBr2 in 40 mL of THF. The mixture was
refluxed for 2 h and then added to a solution of freshly distilled
GeCl4 (11.16 g, 52 mmol) in 40 mL of THF. The mixture was
stirred at room temperature overnight and then reduced by
LiAlH4 (3.95 g, 104 mmol) in 60 mL of THF. After 1 h at
The bond length data and the spectroscopic study of
11 suggest a similar preponderant form A with a
remaining positive charge on the germanium atom.
In contrast, with DMSO (compound 12), a delocaliza-
tion of the positive charge onto the sulfur atom can be
envisaged. The infrared spectrum of 12 shows a shift
of ν(Ge-H) to lower frequency, in agreement with a
decreasing positive charge on germanium. Moreover,
the resonances of the methyl groups of DMSO are
shifted slightly to lower field (∆δ(CH3S) ≈ 0.40 ppm)
as a result of the positive character of the sulfur atom.
Several attempts to prepare germanols have been
made. All the reactions of germyl triflates and iodides
(16) Xie, Z.; Bau, R.; Reed, C. A. J . Chem. Soc., Chem. Commun.
1994, 2519.
(17) Shirley, D. A.; Cheng, C. F. J . Organomet. Chem. 1969, 20, 251.

2226 Organometallics, Vol. 17, No. 11, 1998
Cosledan et al.
reflux, hydrolysis, extraction, drying with Na2SO4, and con-
centration, the residue was distilled, resulting in a mixture of
1 (60%) and methoxynaphthalene (40%) according to the 1H
NMR spectrum. The mixture was dissolved in the least
amount of diethyl ether possible and cooled to -30 °C until
compound 1 precipitated. The crystals were isolated by
decantation and dried in vacuo.
309 ((M - I), 100%). Anal. Calcd for C17H15GeIO: C, 46.96;
H, 3.48. Found: C, 46.71; H, 3.38.
1
8 (87%): mp 132-134 °C; H NMR (CDCl3) δ 3.63 (s, 6H,
OCH3), 6.78 (dd, J 3 ) 6.4 Hz, J 4 ) 2.3 Hz, 2H, H7), 7.23-7.53
(m, 6H, C10H6), 7.35 (s, 1H, GeH), 7.78-7.90 (m, 4H, C10H6);
13C NMR (CDCl3) δ 54.26 (OCH3), 105.15, 121.45, 126.08,
126.37, 127.32, 129.89, 131.32, 134.94, 135.20, 154.97 (C10H6);
IR (Nujol) 2122.0 cm-1 (GeH); MS (EI, 10 eV) m/z 389 ((M -
1
1: 3.90 g (32%); mp 54-56 °C; H NMR (CDCl3) δ 3.95 (s,
3H, OCH3), 4.63 (s, 3H, GeH3), 6.82 (dd, J 3 ) 5.7 Hz, J 4 ) 2.9
Hz, 1H, H7), 7.25-7.49 (m, 3H, C10H6), 7.73 (dd, J 3 ) 6.9 Hz,
J 4 ) 1.5 Hz, 1H, H2), 7.80 (dd, J 3 ) 7.9 Hz, J 4 ) 1.5 Hz, 1H,
H4); 13C NMR (CDCl3) δ 54.50 (OCH3), 104.81, 121.31, 125.91,
126.10, 127.75, 129.41, 134.87, 136.17, 155.94 (C10H6); IR (neat)
2072.1, 2023.5 cm-1 (GeH); MS (EI, 50 eV) m/z 234 ((M+), 32%)
216 ((M - 2H - CH4), 18%). Anal. Calcd for C11H12GeO: C,
56.75; H, 5.20. Found: C, 56.79; H, 5.21.
I), 35%), 374 ((M - CH3I), 100%). Anal. Calcd for C22H19
GeIO2: C, 51.32, H, 3.72. Found: C, 51.03; H, 3.67.
-
Th er m olysis of 8. A solution of 8 (0.23 g, 0.44 mmol) in
CH3CN (5 mL) was heated at reflux for 24 h. After concentra-
tion of the solvent in vacuo, the residue was washed with
pentane (3 × 4 mL), giving a white powder which was isolated
by decantation and drying.
9: 0.14 g (85%); mp 222-224 °C; 1H NMR (CDCl3) δ 4.35 (s,
3H, OCH3), 7.19 (s, 1H, GeH), 6.97-7.91 (m, 11H, C10H6), 8.11
(dd, J 4 ) 1.4 Hz, J 3 ) 6.7 Hz, 1H, H2); 13C NMR (CDCl3) δ
56.36 (OCH3), 104.85, 122.22, 125.90, 126.97, 128.55, 130.55,
132.22, 132.56, 134.40, 161.72 (free C10H6), 107.18, 116.17,
126.97, 127.95, 128.32, 128.40, 129.61, 133.38, 154.35 (cyclic
Gen er a l P r oced u r e for th e Syn th esis of 4-6. Trifluo-
romethanesulfonic acid (1 mmol) was added slowly to a
solution of the respective (8-methoxynaphthyl)germane (1-
3; 1 mmol) in diethyl ether (15 mL). The reaction mixture
was stirred for 1 h at 30 °C. After evaporation of the solvent
in vacuo, 10 mL of pentane was introduced with stirring until
a white solid precipitated. This powder was washed with
freshly distilled pentane (2 × 3 mL) and then isolated by
decantation and drying in vacuo.
C
10H6); IR (Nujol) 2086.6 cm-1 (GeH); MS (EI, 70 eV) m/z 374
((M+), 68%), 358 ((M - CH4), 18%). This compound is unstable
in solution and cannot be recrystallized.
Rea ction of 6 w ith Ben zyla m in e. Benzylamine (2.44 mL,
0.02 mmol) was added to a solution of 6 (0.012 g, 0.02 mmol)
in 0.4 mL of CDCl3 in an NMR tube. The quantitative
formation of compound 10 was observed: 1H NMR (CDCl3) δ
3.29 (s, 8H, OCH3 and CH2N), 6.58 (d, J 3 ) 6.7 Hz, 2H, H7),
7.15-7.61 (m, 11 H, C10H6, NH2 and GeH), 7.75 (d, J 3 ) 7.4
Hz, 2H, H2).
Rea ction of 6 w ith H2O. H2O (0.012 g, 0.66 mmol) was
added to a solution of 6 (0.35 g, 0.66 mmol) in diethyl ether
(20 mL) at room temperature. The solvent was evaporated in
vacuo to give a white powder identified as 11: 0.36 g (quantita-
tive yield). Crystals suitable for X-ray analysis were obtained
by dissolving the powder in a large excess of diethyl ether.
The solution was decanted and cooled at 5 °C for 3 weeks.
11: mp 120-140 °C dec; 1H NMR (CDCl3) δ 3.77 (s, 6H,
OCH3), 6.86 (dd, J 3 ) 6.5 Hz, J 4 ) 2.1 Hz, 2H, H7), 7.33-7.60
(m, 6H, C10H6), 7.76 (d, J 3 ) 6.3 Hz, 3H, C10H6 and GeH), 7.94
(dd, J 3 ) 7.9 Hz, J 4 ) 1.2 Hz, 2H, C10H6), 7.33-8.00 (m, 2H,
H2O); 13C NMR (CDCl3) δ 54.91 (OCH3), 105.21, 122.00, 126.45,
126.85, 127.64, 128.44, 130.78, 133.85, 134.71, 154.36 (C10H6);
19F NMR (CDCl3) δ -2.55 (s); IR (Nujol) 2165.3 (GeH), 3000.0
cm-1 (HOSO3). Anal. Calcd for C23H21F3GeO6: C, 49.77; H,
3.81. Found: C, 49.78; H, 3.75.
1
4 (85%): mp 115-117 °C; H NMR (CDCl3) δ 4.14 (s, 3H,
OCH3), 6.69 (s, 2H, GeH2), 6.95 (dd, J 3 ) 6.8 Hz, J 4 ) 1.8 Hz,
1H, H7), 7.35-8.05 (m, 5H, C10H6); 13C NMR (CDCl3) δ 56.25
(OCH3), 105.08, 122.35, 122.70, 126.31, 127.66, 130.39, 132.89,
134.01, 152.96 (C10H6), 119.19 (q, J CF ) 318.2 Hz, CF3); 19F
NMR (CDCl3) δ -2.40 (s); IR (Nujol) 2121.4, 2109.6 cm-1
(GeH); MS (EI, 70 eV) m/z 382 ((M+), 59%); 233 ((M - OSO2-
CF3), 100%). Anal. Calcd for C12H11F3GeO4S: C, 37.84; H,
2.91. Found: C, 37.71; H, 2.86.
1
5 (42%): mp 131-134 °C; H NMR (CDCl3) δ 3.74 (s, 3H,
OCH3), 6.84 (dd, J 3 ) 7.1 Hz, J 4 ) 1.5 Hz, 1H, H7), 7.25-7.80
(m, 9H, C10H6, C6H5, GeH), 8.02 (dd, J 3 ) 8.3 Hz, J 4 ) 1.4 Hz,
1H, H4), 8.16 (dd, J 3 ) 6.8 Hz, J 4 ) 1.4 Hz, 1H, H2); 13C NMR
(CDCl3) δ 55.15 (OCH3), 104.90, 122.53, 123.10, 126.34, 127.66,
131.19, 133.68, 134.14, 152.77 (C10H6), 128.93, 130.68, 133.12,
133.82 (C6H5); 19F NMR (CDCl3) δ -2.43 (s); IR (Nujol) 2151.5
cm-1 (GeH); MS (EI, 70 eV) m/z 458 ((M+), 100%) 309 ((M -
OSO2CF3), 40%). Anal. Calcd for C18H15F3GeSO4: C, 47.31;
H, 3.31. Found: C, 46.65; H, 3.30.
1
6 (85%): mp 122-125 °C; H NMR (CDCl3) δ 3.76 (s, 6H,
OCH3), 6.86 (dd, J 3 ) 6.6 Hz, J 4 ) 2.1 Hz, 2H, H7), 7.32-7.80
(m, 8H, C10H6), 7.85 (s, 1H, GeH), 7.94 (dd, J 3 ) 7.9 Hz, J 4
)
1.5 Hz, 2H, C10H6); 13C NMR (CDCl3) δ 54.80 (OCH3), 105.17,
121.88, 126.36, 126.74, 127.52, 128.32, 130.68, 133.73, 134.58,
154.23 (C10H6); 19F NMR (CDCl3) δ -2.56 (s); IR (Nujol) 2170.5
cm-1 (GeH); MS (CI, CH4) m/z 539 ((M + 1), 1%), 538 ((M+),
4%), 389 ((M - OSO2CF3), 75%). Anal. Calcd for C23H19F3-
GeSO5: C, 51.44; H, 3.57. Found: C, 51.43; H, 3.73. Crystals
suitable for X-ray analysis were obtained by recrystallization
from dry and degassed cyclohexane.
Rea ction of 6 w ith DMSO. DMSO (43 mL, 0.59 mmol)
was added to a solution of 6 (0.32 g, 0.59 mmol) in CHCl3 (3
mL) and pentane (2 mL). The mixture was stirred for 10 min
at room temperature. After evaporation of the solvent, 1H
NMR analysis showed the formation of complex 12. Five
milliliters of CHCl3 was added to the residue, and the solution
was cooled to -30 °C for 3 weeks to give colorless crystals.
These were washed with pentane (3 × 5 mL) and dried under
a current of argon, leading to 12.
Gen er a l P r oced u r e for th e P r ep a r a tion of Ger m yl
Iod id es 7 a n d 8. Iodine (0.29 mmol) was added to a solution
of the (8-methoxynaphthyl)germane (0.65 mmol) in benzene
(10 mL). The mixture was stirred for 2 h at room temperature.
The solvent was reduced by half and 30 mL of pentane was
added. After 48 h at -30 °C, the white solid was isolated by
decantation, washed with pentane (2 × 5 mL), and dried in
vacuo.
7 (48%): mp 122 °C; 1H NMR (CDCl3) δ 3.60 (s, 3H, OCH3),
6.78 (dd, J 3 ) 6.8 Hz, J 4 ) 1.8 Hz, 1H, H7), 6.91 (s, 1H, GeH),
7.23-7.73 (m, 8H, C10H6 and C6H5), 7.95 (dd, J 3 ) 8.2 Hz, J 4
) 1.3 Hz, 1H, H4), 8.44 (dd, J 3 ) 6.8 Hz, J 4 ) 1.3 Hz, 1H, H2);
13C NMR (CDCl3) δ 54.16 (OCH3), 104.86, 121.66, 123.10,
126.14, 126.82, 127.91, 130.59, 138.56, 138.84, 154.00 (C10H6),
128.36, 129.57, 132.42, 134.56 (C6H5); IR (Nujol) 2094.9 cm-1
(GeH); MS (EI, 20 eV) m/z 436 ((M+), 1%), 435 ((M - H), 5%),
12 0.39 g (89%); mp 58-70 °C dec; 1H NMR (CDCl3) δ 2.92
(s, 6H, CH3S), 3.81 (s, 6H, OCH3), 6.93 (dd, J 3 ) 6.1 Hz, J 4
)
2.4 Hz, 2H, H7), 7.37-7.83 (m, 9H, C10H6 and GeH), 7.97 (dd,
J 3 ) 7.2 Hz, J 4 ) 2.2 Hz, 2H, C10H6); 13C NMR (CDCl3) δ 37.87
(CH3S), 55.39 (OCH3), 106.16, 122.47, 126.79, 127.60, 128.26,
131.22, 133.32, 134.78, 154.04 (C10H6);19F NMR (CDCl3) δ
-3.52 (s); IR (Nujol) 2121.4 cm-1 (GeH). Anal. Calcd for
C
23H21F3GeSO6 (CHCl3): C, 42.51; H, 3.57. Found: C, 42.03;
H, 3.54.
P r ep a r a tion of Ger m oxa n es 13-15. A stoichiometric
mixture of H2O and Et3N was added to a solution of germyl
triflate 4, 5, or 6 (1 mmol). The mixture was stirred for 1 h at
room temperature. An excess of water was then introduced.
After extraction with ether and drying over Na2SO4, the

Reactivity of Germanium Triflates and Iodides
Organometallics, Vol. 17, No. 11, 1998 2227
solution was concentrated in vacuo and gave white powders,
which were identified as the corresponding oxides.
(CDCl3) δ 53.94 (OCH3), 104.21, 120.93, 125.23, 126.12, 128.37,
128.74, 134.21, 134.76, 135.76, 156.18 (C10H6); IR (Nujol)
2069.9cm-1 (GeH); MS (CI, CH4) m/z 793 ((M + H), 7%).
Correct analyses were obtained by recrystallization from THF.
Anal. Calcd for C44H38Ge2O5: C, 66.73; H, 4.83. Found: C,
66.31; H, 4.86.
13 (45%): mp 106-109 °C; 1H NMR (CDCl3) δ 3.97 (s, 6 H,
OCH3), 6.12 (s, 4H, GeH2), 6.83 (dd, J 3 ) 6.4 Hz, J 4 ) 2.1 Hz,
2H, H7), 7.27-7.66 (m, 6H, C10H6), 7.86 (dd, J 3 ) 8.1 Hz, J 4
)
1.2 Hz, 2H, H4), 8.25 (dd, J 3 ) 6.6 Hz, J 4 ) 1.2 Hz, 2H, H2);
13C NMR (CDCl3) δ 54.74 (OCH3), 104.52, 121.37, 125.71,
126.51, 128.51, 128.91, 130.99, 133.12, 134.73, 155.88 (C10H6);
IR (Nujol) 2063.0 and 2042.4 (GeH), 739.8 cm-1 (GeOGe); MS
(EI, 70 eV) m/z 480 ((M+), 2%), 322 ((M - (CH3O)NpH), 13%).
Correct analyses were obtained by recrystallization from THF.
Anal. Calcd for C22H22Ge2O2: C, 55.10; H, 4.62. Found: C,
54.81; H, 4.66.
X-r a y Cr ysta llogr a p h y. Suitable crystals of 6 and 11 were
sealed in a capillary. The data collection was carried out on
a
Stoe ′IPDS image system with MoKa radiation. The
structures were solved by direct methods. The full-matrix
least-squares refinement was done on F2 and the hydrogen
atoms (expect Ge-H) were geometrically fixed on the ap-
propriate carbon and oxygen atoms.18 Crystal data and the
results of the refinement are collected in Table 2.19
14 (37%): mp 140 °C; two diastereoisomers were obtained
in the ratio 50/50; 1H NMR (CDCl3) δ 3.52 (s, 6H, OCH3), 6.58
and 6.59 (s, 2H, GeH), 6.69 (dd, J 3 ) 6.9 Hz, J 4 ) 1.9 Hz, 2H,
H7), 7.16-7.68 (m, 16H, C10H6 and C6H5), 7.86 (dd, J 3 ) 8.2
Su p p or tin g In for m a tion Ava ila ble: Tables of crystal
data, atom coordinates, thermal parameters, and bond dis-
tances and angles for 6 and 11 and a plot of conductivity
measurements (13 pages). Ordering information is given on
any current masthead page.
Hz, J 4 ) 1.9 Hz, 2H, H4), 8.34 and 8.42 (dd, J 3 ) 6.7 Hz, J 4
)
1.5 Hz, 2H, H2); 13C NMR (CDCl3) δ 54.01 (OCH3), 104.36,
121.29, 125.67, 126.48, 129.20, 129.35, 131.36 and 131.48,
134.30 and 134.42, 134.79, 155.66 (C10H6), 127.93, 128.70,
133.47, 140.77 and 140.82 (C6H5); IR (Nujol) 2046.8 cm-1
(GeH); MS (EI, 20 eV) m/z 632 ((M+), 2%). Anal. Calcd for
OM970963F
C
34H30Ge2O3: C, 64.64; H, 4.79. Found: C, 64.41; H, 4.91.
(18) Sheldrick, G. M. SHELXS-86 and SHELXL-93, Programs for
Crystal Structure Determination; University of Go¨ttingen, Go¨ttingen,
Germany.
(19) Further details of the crystal structure investigation have been
deposited at the CCDC and may be obtained on quoting the depository
number (No. 101463), the names of the authors, and the journal
citation.
15 (47%): mp 225-230 °C; 1H NMR (CDCl3) δ 3.25 (s, 12H,
OCH3), 6.53 (dd, J 3 ) 6.8 Hz, J 4 ) 2.0 Hz, 4H, H7), 7.01 (dd,
J 3 ) 6.8 Hz, J 4 ) 7.9 Hz, 4H, H5), 7.08 (s, 2H, GeH), 7.19-
7.48 (m, 8H, C10H6), 7.56 (dd, J 3 ) 7.0 Hz, J 4 ) 1.4 Hz, 4H,
H2), 7.69 (dd, J 3 ) 8.1 Hz, J 4 ) 1.4 Hz, 4H, H4); 13C NMR