Synthesis of alkynyl-substituted 9,10-dimetallatriptycenes of group 14 and their application in the preparation of a novel class of organometallic oligomers

Article abstract of DOI:10.1021/om980073f

The preparation of ((trimethylsilyl)ethynyl)germanium trichloride (4) allowed the synthesis of various alkynyl-substituted 9,10-dimetallatriptycenes via a simple one-pot synthetic procedure. For example, reaction of 4 with o-phenylenemagnesium (1) gave access to 9,-10-(RC≡C)₂-9,10-digermatriptycenes (5, R = SiMe₃; 6, R = H), while reaction of 4 with tris-(o-(chloromagnesio)phenyl)phenylgermane (2a) furnished 9-(RC≡C)-10-phenyl-9,10-digermatriptycenes (7, R = SiMe₃; 8, R = H). The synthetic potential of these compounds in the preparation of rigid organometallic oligomers with conjugated spacers was demonstrated by the oxidative coupling of 8, which furnished 1,4-bis(9-(10-phenyl-9,10-digermatriptycyl))-buta-1,3-diyne (9), whose X-ray crystal structure was determined, and the hydrosilylation of 8 with 10-phenyl-10-germa-9-silatriptycene (3a), which yielded trans-1-(9-(10-phenyl-9,-10-digermatriptycyl))-2-(9-(10-phenyl-9-sila-10- germatriptycyl))ethene (10).

Full text of DOI:10.1021/om980073f

1762
Organometallics 1998, 17, 1762-1768
Syn th esis of Alk yn yl-Su bstitu ted
9,10-Dim eta lla tr ip tycen es of Gr ou p 14 a n d Th eir
Ap p lica tion in th e P r ep a r a tion of a Novel Cla ss of
Or ga n om eta llic Oligom er s
Matheus A. Dam,† Wilhelmus J . Hoogervorst,† Franciscus J . J . de Kanter,†
Friedrich Bickelhaupt,*,† and Anthony L. Spek‡
Scheikundig Laboratorium, Vrije Universiteit, De Boelelaan 1083, NL-1081 HV Amsterdam,
The Netherlands, and Bijvoet Center for Biomolecular Research, Crystal and Structural
Chemistry, Utrecht University, Padualaan 8, NL-3584 CH Utrecht, The Netherlands
Received February 3, 1998
The preparation of ((trimethylsilyl)ethynyl)germanium trichloride (4) allowed the synthesis
of various alkynyl-substituted 9,10-dimetallatriptycenes via a simple one-pot synthetic
procedure. For example, reaction of 4 with o-phenylenemagnesium (1) gave access to 9,-
10-(RCtC)2-9,10-digermatriptycenes (5, R ) SiMe3; 6, R ) H), while reaction of 4 with tris-
(o-(chloromagnesio)phenyl)phenylgermane (2a ) furnished 9-(RCtC)-10-phenyl-9,10-diger-
matriptycenes (7, R ) SiMe3; 8, R ) H). The synthetic potential of these compounds in the
preparation of rigid organometallic oligomers with conjugated spacers was demonstrated
by the oxidative coupling of 8, which furnished 1,4-bis(9-(10-phenyl-9,10-digermatriptycyl))-
buta-1,3-diyne (9), whose X-ray crystal structure was determined, and the hydrosilylation
of 8 with 10-phenyl-10-germa-9-silatriptycene (3a ), which yielded trans-1-(9-(10-phenyl-9,-
10-digermatriptycyl))-2-(9-(10-phenyl-9-sila-10-germatriptycyl))ethene (10).
Sch em e 1
In tr od u ction
Organometallic polymers in which the metal centers
are linked via unsaturated ligands have gained consid-
erable interest due to their possible application in areas
such as nonlinear optics1 and molecular devices such
as wires and switches.2,3
Our interest in this field of chemistry was raised by
a crystallographic study4 of the substituted 9,10-dimet-
allatriptycenes 34,5 (obtained via reaction of o-phenyle-
nemagnesium (1)6,7 with the corresponding metal tri-
halides via the intermediate tri-Grignard reagent 2; see
Scheme 1), which indicated that in these compounds the
two metal atoms are in closer contact than the sum of
their van der Waals radii. It was envisioned that the
through-space interaction between these metal atoms
and the interaction of filled metal orbitals with vacant
p* orbitals of the carbon spacer8 may be used for the
transmission of electrical or optical signals in organo-
metallic polymers.
containing a group 14 9,10-dimetallatriptycene back-
bone. Various novel alkynyl-substituted 9,10-diger-
matriptycenes are described, and their potential for the
preparation of organometallic oligomers is demonstrated
by the transformation of 9-ethynyl-10-phenyl-9,10-di-
germatriptycene (8) into the dimers 1,4-bis(9-(10-phen-
yl-9,10-digermatriptycyl))buta-1,3-diyne (9) and trans-
1-(9-(10-phenyl-9,10-digermatriptycyl))-2-(9-(10-phenyl-
9-sila-10-germatriptycyl))ethene (10). All compounds
were characterized by their spectral data and, in the
case of 9, via a single-crystal X-ray structure determi-
nation.
In this paper we wish to report the general synthetic
approach toward new types of organometallic oligomers
† Vrije Universiteit.
‡ Utrecht University.
(1) Long, N. J . Angew. Chem. 1995, 107, 37.
(2) Ward, M. D. Chem. Ind. 1996, 568.
(3) Harriman, A.; Ziessel, R. J . Chem. Soc., Chem. Commun. 1996,
1707.
(4) Dam, M. A.; de Kanter, F. J . J .; Bickelhaupt, F.; Smeets, W. J .
J .; Spek, A. L.; Fornies-Camer, J .; Cardin, C. J . J . Organomet. Chem.,
in press.
(5) Dam, M. A.; Akkerman, O. S.; de Kanter, F. J . J .; Bickelhaupt,
F.; Veldman, N.; Spek, A. L. Chem. Eur. J . 1996, 2, 1139.
(6) Tinga, M. A. G. M.; Akkerman, O. S.; Bickelhaupt, F.; Horn, E.;
Spek, A. L. J . Am. Chem. Soc. 1991, 113, 3604.
(7) Tinga, M. A. G. M.; Schat, G.; Akkerman, O. S.; Bickelhaupt,
F.; Horn, E.; Kooijman, H.; Smeets, W. J . J .; Spek, A. L. J . Am. Chem.
Soc. 1993, 115, 2808.
Str a tegic Con sid er a tion s
The implementation of our one-pot synthetic approach
toward substituted 9,10-dimetallatriptycenes (Scheme
(8) Davies, S. J .; J ohnson, B. F. G.; Lewis, J .; Raithby, P. R. J .
Organomet. Chem. 1991, 414, C51.
S0276-7333(98)00073-9 CCC: $15.00 © 1998 American Chemical Society
Publication on Web 04/09/1998

9,10-Dimetallatriptycenes of Group 14
Organometallics, Vol. 17, No. 9, 1998 1763
Sch em e 2
Sch em e 3a
1) in the preparation of organometallic polymers re-
quired a synthetic strategy consisting of two steps. The
first step encompasses the synthesis of monomers, e.g.
9,10-dimetallatriptycenes containing a suitable sub-
stituent at the bridgehead positions, which in the second
step are connected to furnish oligomeric structures. The
acetylene group was envisioned to be a suitable sub-
stituent, as the dimerization and hydrosilylation of
substituted acetylenes are well-known,9-11 and these
reactions would furnish a 1,3-butadiyne or a ethene
moiety as a conjugating spacer. The introduction of the
acetylene function at the bridgehead position of the
(monomeric) 9,10-dimetallatriptycene may be achieved
in different ways (Scheme 2). One consists of the
reaction of 2 equiv of ((trimethylsilyl)ethynyl)germa-
nium trichloride (4) with 3 equiv of o-phenylenemag-
nesium (1) to furnish 9,10-bis((trimethylsilyl)ethynyl)-
9,10-digermatriptycene (5), which after desilylation
yields 9,10-diethynyl-9,10-digermatriptycene (6) as a
“repeating unit”. Another route is the reaction of 1
equiv of 4 with 1 equiv of tris(o-(chloromagnesio)-
phenyl)phenylgermane (2a ; obtained via reaction of 1
molar equiv of PhGeCl3 with three C6H4Mg units of 1),5
to furnish 7, which after desilylation may yield 9-ethy-
nyl-10-phenyl-9,10-digermatriptycene (8) as a “stopper”.
The availability of both repeating unit 6 and stopper 8
is essential for the preparation of well-defined oligomeric
structures such as dimers and trimers.
a
Conditions: (a) 4, -10 °C to room temperature (for 2d ).
(b) PhGeCl3, -10 °C to room temperature (for 2a ). (c) 4, -10
°C to room temperature. (d) KOH, H2O/THF.
Syn th esis of “Rep ea tin g Un it” 6. The preparation
of the dialkynyl-substituted triptycene 5 was performed
via a simple one-pot procedure: the tri-Grignard re-
agent 2d (generated in situ by reaction of 1 (3 molar
equiv of the formally monomeric unit C6H4Mg) with 4
(1 molar equiv; Scheme 3) was reacted with 1 equiv of
4 to furnish 5. However, the yield of 5 was rather poor
(e19%) due to the formation of many byproducts. The
formation of these byproducts, probably trimethylsilyl-
substituted oligomers and germoxanes, may be ex-
plained by a less selective formation of the tri-Grignard
intermediate 2d in comparison to its phenyl analogue
2a .4 Although we were able to remove many of the
byproducts, we did not obtain 5 in analytically pure
form. Removal of the trimethylsilyl groups was easily
accomplished via treatment of crude 5 with 2 equiv of
aqueous KOH,13 which gave pure 9,10-diethynyl-9,10-
Resu lts a n d Discu ssion
Syn th esis of ((Tr im eth ylsilyl)eth yn yl)ger m a n i-
u m Tr ich lor id e (4). We were able to prepare the novel
compound 4 via reaction12 of trimethylsilylacetylene
with GeCl4 and triethylamine in benzene. Workup
(filtration and vacuum distillation) furnished a colorless
1
liquid which was identified by H and 13C NMR spec-
troscopy as pure 4.
(9) Eglinton, G.; McCrae, W. Adv. Org. Chem. 1963, 4, 225.
(10) Raphael, R. A. Acetylene Compounds in Organic Synthesis;
Academic Press: New York, 1955.
(11) Lewis, L. N.; Sy, K. G.; Bryant, G. L., J r.; Donahue, P. E.
Organometallics 1991, 10, 3750.
(12) Efimova, I. V.; Kalganov, B. E.; Kazankova, M. A.; Lutsenko,
I. F. J . Gen. Chem. USSR (Engl. Transl.) 1984, 54, 410.
(13) Takahashi, S.; Koroyama, Y.; Sonogashira, K.; Hagihara, N.
J . Chem. Soc., Chem. Commun. 1980, 627.

1764 Organometallics, Vol. 17, No. 9, 1998
Dam et al.
Sch em e 4
Ta ble 1. Selected Bon d Len gth s (Å) a n d Bon d
However, the solubility in bromobenzene was sufficient
1
to allow identification via H and 13C NMR spectroscopic
An gles (d eg) of 9‚0.5C6H5Cl (see F igu r e 2)
Ge(1)‚‚‚Ge(2)
Ge(1a)‚‚‚Ge(2a)
Ge(2)‚‚‚Ge(2a)
Ge(1)‚‚‚Ge(2a)
Ge(1a)‚‚‚Ge(2)
Ge(1)‚‚‚Ge(1a)
Ge-Pha
3.0439(8)
3.0421(7)
7.520(1)
10.537(2)
10.543(2)
13.543(2)
1.933(4)
Ge-Ra
1.896(4)
1.962(4)
1.940(4)
1.398(6)
1.189(6)
1.383(6)
analysis, and these data indicated that the reaction had
indeed furnished dimer 9 (isolated yield: 74%). Ad-
ditional proof for the assigned structure came from an
X-ray structure determination of a single crystal of 9
which was obtained by crystallization from chloroben-
zene (vide infra).
a
Ge(Ph)-Cipso
a
Ge(R)-Cipso
Cipso-Cipso
-CtC-
tC-Ct
a
a
R1 (Cipso-Ge(Ph)-Cipso
)
102.8(2) γ2 (Ge(R)-Cipso-C)a 125.0(4)
tr a n s-1-(9-(10-P h en yl-9,10-d iger m a tr ip tycyl))-2-
(9-(10-ph en yl-10-ger m a-9-silatr iptycyl))eth en e (10).
Although dimer 9 was obtained in a satisfactory yield,
its poor solubility in common solvents foreshadowed
practical problems for the preparation of larger oligo-
mers. This low solubility must, at least in part, be due
to the high symmetry of this linear molecule. To
increase solubility, we attempted to prepare a less
symmetrical oligomeric structure via hydrosilylation
of 8 with 10-phenyl-10-germa-9-silatriptycene (3a )4
(Schemes 2 and 4). The reaction was performed by
stirring a THF solution of 8 and 3a with a catalytic
amount of Speier’s catalyst (H2PtCl6‚6H2O).11,16 The
solubility in CDCl3 of the white solid obtained after
workup was sufficient to allow 1H and 13C spectroscopic
analysis. The spectra obtained revealed the presence
of two unsymmetrical triptycene moieties and a trans-
substituted ethene unit (relative ratio 1:1:1). It was
therefore concluded that the reaction had indeed fur-
nished trans-1-(9-(10-phenyl-9,10-digermatriptycyl))-2-
(9-(10-phenyl-10-germa-9-silatriptycyl))ethene (10); the
isolated yield of 10 was 65%.
Sin gle-Cr ysta l X-r a y Str u ctu r e Deter m in a tion of
Dim er 9. The molecular structure of 9 is depicted in
Figure 1. Selected bond lengths, bond angles, and
dihedral angles are presented in Table 1, and the
crystallographic data for 9 are summarized in Table 2.
In the triclinic unit cell, two adjacent molecules of 9
are arranged in a pairwise fashion together with one
molecule of chlorobenzene, which is disordered over an
inversion center. From Figure 1 it can be seen that, in
each molecule of 9, one phenyl substituent is disordered
over two orientations, represented by C(19)-C(24) and
C(19)′-C(24)′, respectively, which are populated in a 1:1
ratio. The two triptycene moieties are connected by a
1,3-butadiyne spacer and are related by a noncrystal-
lographic 2-fold axis perpendicular to C(26)-C(26a).
Corresponding values for distances and angles in the
other half of the molecule are given in brackets. The
a
R2 (Cipso-Ge(R)-Cipso
)
104.2(2) Ge(2)-CtC
115.4(3) Ge(2a)-CtC
114.4(3) CtC-C
125.3(3)
174.0(5)
176.7(5)
177.1(6)
a
â1 (Ge(Ph)-Cipso-Cipso
)
a
â2 (Ge(R)-Cipso-Cipso
)
γ1 (Ge(Ph)-Cipso-C)a
Ge(1)-Ge(2)-Ge(2a)-Ge(1a)
14.9(2)
a
Average value.
digermatriptycene (6) in an isolated yield of 71%. The
identity of the diethynyldigermatriptycenes 5 and 6
followed from comparison of the spectroscopic data (1H
and 13C NMR, NOE and CH correlation experiments)
with those of known group 14 9,10-dimetallatripty-
cenes4,5,14 and, in the case of 6, from elemental analysis.
Syn th esis of “Stop p er ” 8. The preparation of the
trimethylsilyl compound 7 was again performed via our
one-pot procedure (Scheme 3): first the tri-Grignard
reagent tris(o-(chloromagnesio)phenyl)phenylgermane
(2a ) was prepared in situ via reaction of 3 equiv of 1
with 1 equiv of PhGeCl3.4 Reaction of 2a with 1 equiv
of 4 gave 7 in an isolated yield of 77%. Desilylation of
7 was accomplished with 1 equiv of aqueous KOH,
which afforded 8 in an isolated yield of 93%. The
identity of ethynyl-digermatriptycenes 7 and 8 followed
from elemental analysis and from the spectroscopic data
(1H and 13C NMR, NOE and CH correlation experi-
ments).
After having prepared the monomers 6 and 8, we
focused our attention on the application of these com-
pounds in the preparation of organometallic oligomers.
1,4-Bis(9-(10-ph en yl-9,10-diger m atr iptycyl))bu ta-
1,3-d iyn e (9). Our first attempt to prepare organome-
tallic oligomers was the connection of two molecules of
stopper 8 via a Hay coupling15 (Scheme 4). The reaction
was performed by bubbling oxygen through a heated
solution of 8 and CuCl (5%) in pyridine. The identifica-
tion of the white solid obtained after workup was
hampered by its poor solubility in common solvents.
(14) Takahashi, M.; Hatano, K.; Kawada, Y.; Koga, G.; Tokitoh, N.;
Okazaki, R. J . Chem. Soc., Chem. Commun. 1993, 1850.
(15) Hay, A. S. J . Chem. Soc., Chem. Commun. 1960, 1275.
(16) Speier, J . L. Adv. Organomet. Chem. 1979, 17, 407.

9,10-Dimetallatriptycenes of Group 14
Organometallics, Vol. 17, No. 9, 1998 1765
F igu r e 1. ORTEP plot of 9‚0.5C6H5Cl with ellipsoids drawn at the 50% probability level. Hydrogens are omitted for
clarity.
Ta ble 2. Cr ysta l Da ta a n d Deta ils of th e Str u ctu r e
Deter m in a tion of 9‚0.5C6H5Cl
empirical formula
fw
C52H34Ge4‚0.5C6H5Cl
1005.56
cryst syst
a (Å)
b (Å)
P1h (No. 2)
8.4807(11)
12.9985(19)
21.141(3)
c (Å)
R (deg)
â (deg)
γ (deg)
V (Å3)
Z
72.697(12)
80.666(11)
79.253(11)
2171.8(5)
2
D(calc) (g cm-3
F(000)
)
1.538
1006
28.1
µ(Mo KR) (cm-1
cryst size (mm)
temp (K)
)
0.50 × 0.62 × 0.12
150
radiation; λ (Å)
Mo KR; 0.710 73
1.0, 27.5
θ
min, θmax, (deg)
scan (type & range) (deg)
data set
0.86 + 0.35 tan θ
-11 to 0; -16 to +16;
-27 to +27
10 624, 9945; 0.075
7480
0.214-0.680
9945, 579
0.0503, 0.1332, 1.01
0.00, 0.00
-0.98, 0.89
total of unique no. of data; R(int)
no. of obsd data (I > 2.0σ(I))
transmissn range (empirical)
N
ref, Npar
R, Rw, Sa
max and av shift/error
min and max resd dens (eÅ-3
)
a
w ) 1/(σ2(Fo2) + (0.089P)2 + 2.5065P), where P ) (Fo2 + 2Fc2)/3
F igu r e 2. Schematic representation of 9 and the number-
ing applied for 9 and 10.
C-C and CtC bond lengths of this spacer (1.383(6) and
1.189(6) Å [1.190(6) Å], respectively) are in accordance
with those reported for buta-1,3-diyne (1.389(5) and
1.202(7) Å).17 However, the bond angles around the sp-
hybridized C atoms of the spacer deviate from 180° (Ge-
CtC ) 174.0(5)° [176.7(5)°], CtC-C ) 177.1(6)° [177.3-
(6)°]). As a result, the dihedral angle between the
central axes of the two triptycene moieties is 14.9(2)°.
These triptycene moieties do have the structural fea-
tures of group 14 9,10-dimetallatriptycenes which have
been analyzed and discussed recently.4 For example,
the average “internal” angles at the bridging benzene
rings ân (see Figure 2; â1 ) Ge(Ph)-Cipso-Cipso, â2 ) Ge-
120°, while the average angles Rn (R1 ) Cipso-Ge(Ph)-
C
ipso, R2 ) Cipso-Ge(CtC)-Cipso) (R1 ) 102.8(2)°, R2 )
104.2(2)°) are more acute than 109.5°. In addition, the
two metal atoms within one triptycene moiety are again
in much closer contact (Ge(1)‚‚‚Ge(2) ) 3.0439(8) Å
[3.0421(7) Å]) than the sum of their van der Waals radii
((4.5 Å).18 However, in 9 these contacts are rather
short in comparison to that in 9-methyl-10-phenyl-9,-
10-digermatriptycene (3b; Ge(1)‚‚‚Ge(2) ) 3.0957(19) Å);
they are even shorter than the Si‚‚‚Ge contact in 10-
phenyl-10-germa-9-silatriptycene (3a ; Si(1)‚‚‚Ge(2) )
3.0466(5) Å).4 The short Ge‚‚‚Ge contacts in 9 may be
ascribed to the presence of an acetylene substituent
which is more electronegative than a methyl or phenyl
substituent. The Ge hybrid orbital used for bonding
(CtC)-Cipso-Cipso) are smaller (â1 ) 115.4(3)°, â2
)
114.(3)°) and the average “external angles” γn (γ1 ) Ge-
(Ph)-Cipso-C, γ2 ) Ge(CtC)-Cipso-C) are wider (γ1 )
125.3(3)°, γ2 ) 125.0(4)°) than the standard angle of
(17) Tanimoto, M.; Kuchitsu, K.; Morino, Y. Bull. Chem. Soc. J pn.
1971, 44, 386.
(18) Allinger, N. L. Adv. Phys. Org. Chem. 1976, 13, 1-83.

1766 Organometallics, Vol. 17, No. 9, 1998
Dam et al.
9-((Tr im eth ylsilyl)eth yn yl)-10-p h en yl-9,10-d ih yd r o-9,-
10-d iger m a -9,10[1′,2′]-ben zen oa n th r a cen e (7). At -10 °C,
PhGeCl3 (3.56 mmol in 33.0 mL of toluene) was added over 4
h to 1 (10.68 mmol of the formal monomeric unit C6H4Mg in
169.8 mL of THF). After additional stirring for 1.5 h at -10
°C and for 2 h at 5 °C, the mixture was warmed to room
temperature overnight and then was cooled to -10 °C, and 4
(3.56 mmol in 121.9 mL of toluene) was added over 5 h. After
additional stirring for 2 h at -10 °C and for 1.5 h at 5 °C, the
mixture was stirred at room temperature for 18 h. The
mixture was quenched (H2O/HCl), the solvent was evaporated
in vacuo, and the residue was extracted with toluene (3 × 15
mL). The combined organic layers were dried (MgSO4) and
filtered, and the solvent was evaporated in vacuo. The residue
was dissolved in n-hexane and transferred to a silica column.
The column was washed with n-hexane; then the product was
eluted from the column with benzene. The benzene eluate was
evaporated to dryness to give a white solid (1.51 g, 2.74 mmol,
77%): mp 217 °C; 1H NMR (400 MHz, CDCl3)20 δ 8.13 (m, 3J HH
with the acetylene ligand will therefore have relatively
more p-character, which in turn will leave more s-
character for the hybrid orbitals used for bonding to the
phenylene ligands. This results in shortening of the
bridgehead-to-phenylene bonds and widening of the
internal angle R (Cipso-Ge-Cipso) and brings the bridge-
head atoms in 9 in closer contact than, for example, in
3b. The relatively short Ge‚‚‚Ge contacts in 9 are of
interest, as they may additionally facilitate the through-
space contribution to the transmission of electrochemi-
cal or photochemical transitions along the longitudal
axis of this type of organometallic oligomer.
Con clu sion s
The preparation of the novel compound ((trimethyl-
silyl)ethynyl)germanium trichloride (4) allowed the
development of a simple one-pot synthetic approach
toward various new alkynyl-substituted 9,10-diger-
matriptycenes. The synthetic potential of these com-
pounds in the preparation of organometallic oligomers
with conjugated spacers was demonstrated by the
oxidative coupling of 8, which furnished 9, and the
hydrosilylation of 8 with 3a , which yielded 10. Single-
crystal X-ray structure analysis of 9 revealed relatively
short Ge‚‚‚Ge contacts (3.04 Å) which might allow the
application of this type of organometallic oligomers in
areas such as nonlinear optics and molecular devices
such as wires and switches.
4
5
) 7.6 Hz, J HH ) 1.2 Hz, J HH ) 0.8 Hz, 2H; H(18,22)), 7.89
3
4
5
(m, J HH ) 7.3 Hz, J HH ) 1.3 Hz, J HH ) 0.7 Hz, 3H; H(4,5,-
3
4
5
16)), 7.69 (m, J HH ) 7.4 Hz, J HH ) 1.3 Hz, J HH ) 0.7 Hz,
3
3
4
3H; H(1,8,13)), 7.67 (m, J HH ) 7.6 Hz, J HH ) 7.5 Hz, J HH
)
5
3
1.2 Hz, J HH ) 0.8 Hz, 2H; H(19,21)), 7.64 (m, J HH ) 7.5 Hz,
4J HH ) 1.2 Hz, 1H; H(20)), 7.27 (m, J HH ) 7.5 Hz, J HH ) 7.3
3
3
Hz, 4J HH ) 1.3 Hz, 3H; H(3,6,15)), 7.22 (m, 3J HH ) 7.5 Hz, 3J HH
4
2
) 7.4 Hz, J HH ) 1.3 Hz, 3H; H(2,7,14)), 0.43 (s, J SiH ) 7.1
Hz, 9H; H(25,26,27)); 13C NMR (100 MHz, CDCl3) δ 144.5 (bs;
1
C(8a,9a,12)), 144.2 (bs; C(4a,10a,11)), 136.2 (dt, J CH ) 159.5
3
1
3
Hz, J CH ) 7.2 Hz; C(18,22)), 132.2 (dd, J CH ) 159.5 Hz, J CH
1
3
) 8.5 Hz; C(1,8,13)), 132.1 (dd, J CH ) 161.2 Hz, J CH ) 7.5
1
3
Hz; C(4,5,16)), 130.2 (dt, J CH ) 160.5 Hz, J CH ) 7.4 Hz;
1
3
C(20)), 129.4 (s; C(17)), 129.06 (dd, J CH ) 159.1 Hz, J CH
)
1
3
Exp er im en ta l Section
5.6 Hz; C(19,21)), 127.7 (dd, J CH ) 159.2 Hz, J CH ) 6.9 Hz;
1
3
C(2,7,14)), 127.6 (dd, J CH ) 159.3 Hz, J CH ) 7.1 Hz; C(3,6,-
Gen er a l Meth od s. All manipulations involving organo-
metallic compounds were performed in fully sealed glassware
(“full glass”) using standard high-vacuum techniques19 unless
stated otherwise. NMR spectra were measured at 25 °C on a
Bruker AC 200 spectrometer (1H NMR, 200.0 MHz; 13C NMR,
50.3 MHz) and on a Bruker MSL 400 spectrometer (1H NMR,
400.1 MHz; 13C NMR, 100.6 MHz). Melting points were
measured in a sealed capillary and are uncorrected. Elemental
analyses were carried out at the Mikroanalytisches Labor
Pascher, Remagen, Germany.
Ma ter ia ls. The commercial reagents PhGeCl3, GeCl4, H2-
PtCl6‚6H2O, CuCl, EtOAc, Et3N, HCCl3, pyridine, and (trim-
ethylsilyl)acetylene were used without further purification.
HPLC grade benzene, toluene, n-hexane, and THF were
predried over NaOH and then dried by distillation from liquid
Na/K alloy. o-Phenylenemagnesium (1)6,7 and 10-phenyl-10-
germa-9-silatriptycene (3a )4 were prepared according to the
literature. The applied numbering scheme of 9 and 10 is
depicted in Figure 2.
1
15)), 122.5 (s; C(23)), 98.3 (s; C(24)), 0.1 (q, J CH ) 120.4 Hz;
C(25,26,27)). Anal. Calcd for C29H26Ge2Si: C, 63.58; H, 4.79.
Found: C, 63.19; H, 4.75.
9-E t h yn yl-10-p h en yl-9,10-d ih yd r o-9,10-d iger m a -9,10-
[1′,2′]-ben zen oa n th r a cen e (8). A solution of KOH (0.046 g,
1 mmol) in H2O (1 mL) was added to a solution of 7 (0.265 g,
0.485 mmol) in THF (2 mL). The resulting mixture was stirred
for 1 h and extracted with toluene (2 × 1 mL). The combined
organic layers were dried (MgSO4), filtered and the solvent
was evaporated in vacuo to give a white solid (0.217 g, 0.451
1
mmol, 93%): mp 202 °C; H NMR (400 MHz, CDCl3)20 δ 8.13
3
4
5
(m, J HH ) 7.6 Hz, J HH ) 1.3 Hz, J HH ) 0.8 Hz, 2H; H(18,-
3
4
5
22)), 7.91 (m, J HH ) 7.3 Hz, J HH ) 1.3 Hz, J HH ) 0.7 Hz,
3
4
5
3H; H(4,5,16)), 7.70 (m, J HH ) 7.4 Hz, J HH ) 1.3 Hz, J HH
)
3
3
0.7 Hz, 3H; H(1,8,13)), 7.67 (m, J HH ) 7.6 Hz, J HH ) 7.6 Hz,
4J HH ) 1.3 Hz, J HH ) 0.8 Hz 2H; H(19,21)), 7.65 (m, J HH
)
5
3
4
3
7.6 Hz, J HH ) 1.3 Hz, 1H; H(20)), 7.28 (m, J HH ) 7.4 Hz,
3J HH ) 7.3 Hz, J HH ) 1.3 Hz, 3H; H(3,6,15)), 7.24 (m, J HH
)
4
3
3
4
7.4 Hz, J HH ) 7.4 Hz, J HH ) 1.3 Hz, 3H; H(2,7,14)), 3.00 (s;
((Tr im eth ylsilyl)eth yn yl)ger m a n iu m Tr ich lor id e (4).
Under an N2 atmosphere, GeCl4 (4.60 g, 21 mmol) was added
over 1 h to a solution of (trimethylsilyl)acetylene (2.06 g, 21
mmol) and triethylamine (2.12 g, 21 mmol) in benzene (15 mL).
After additional stirring at 80 °C for 24 h, the mixture was
cooled to room temperature to give a red solution and a white
precipitate. The red solution was filtered, and the solvent was
evaporated in vacuo. The residue was distilled to furnish a
colorless liquid (1.45 g, 5.3 mmol, 25%): bp 82 °C (25 mmHg);
H(24)); 13C NMR (100 MHz, CDCl3) δ 144.5 (bs; C(8a,9a,12)),
1
3
143.9 (bs; C(4a,10a,11)), 136.2 (dt, J CH ) 159.9 Hz, J CH
)
1
3
7.7 Hz; C(18,22)), 132.4 (dd, J CH ) 159.0 Hz, J CH ) 7.2 Hz;
1
3
C(1,8,13)), 132.1 (dd, J CH ) 161.0 Hz, J CH ) 6.9 Hz; C(4,5,-
1
3
16)), 130.3 (dt, J CH ) 160.4 Hz, J CH ) 7.8 Hz; C(20)), 129.3
1
3
(s; C(17)), 129.1 (dd, J CH ) 160.4 Hz, J CH ) 7.8 Hz; C(19,-
1
3
21)), 127.9 (dd, J CH ) 159.3 Hz, J CH ) 7.8 Hz; C(2,7,14)),
1
3
127.8 (dd, J CH ) 159.6 Hz, J CH ) 7.5 Hz; C(3,6,15)), 100.0
1
2
(d, J CH ) 242.1 Hz; C(24)), 76.8 (d, J CH ) 43.8 Hz; C(23)).
Anal. Calcd for C26H18Ge2: C, 65.66; H, 3.82. Found: C,
65.29; H, 3.87.
1
2
1H NMR (C6D6, 200 MHz) δ 0.00 (s, J CH ) 121.0 Hz, J SiH
)
-7.2 Hz, 9H; Si(CH3)3); 13C NMR (C6D6, 50 MHz) δ 119.1 (s;
CCSi(CH3)3), 100.0 (s; CCSi(CH3)3), -1.4 (q, J CH ) 121.0 Hz;
1
9,10-Bis((tr im eth ylsilyl)eth yn yl)-9,10-d ih yd r o-9,10-d i-
ger m a -9,10[1′,2′]-ben zen oa n th r a cen e (5). At -10 °C, 4
CCSi(CH3)3). Anal. Calcd for C5H9GeCl3Si: C, 21.75; H, 3.29;
Ge, 26.3; Cl, 38.5; Si, 10.2. Found: C, 21.74; H, 3.35; Ge, 26.2;
Cl, 38.1; Si, 10.0.
x
(20) Chemical shifts and J HH coupling constants followed from
simulations with the gNMR program21,22 and, if necessary, from NOE
(19) Vreugdenhil, A. D.; Blomberg, C. Recl. Trav. Chim. Pays-Bas
1963, 82, 453.
and CH correlation experiments; for the numbering system, see Figure
2.

9,10-Dimetallatriptycenes of Group 14
Organometallics, Vol. 17, No. 9, 1998 1767
(0.21 mmol in 7.3 mL of toluene) was added over 2 h to 1 (0.64
mmol of the formal monomeric unit C6H4Mg in 10.0 mL of
THF). After additional stirring for 1.5 h at -10 °C and for 2
h at 5 °C, the mixture was warmed to room temperature
overnight and then cooled to -10 °C, and 4 (0.21 mmol in 2.6
mL of toluene) was added over 1 h. After additional stirring
for 2 h at -10 °C and for 1.5 h at 5 °C, the mixture was
warmed to room temperature overnight. The mixture was
quenched (H2O/HCl), the solvent was evaporated in vacuo, and
the residue was extracted with toluene (3 × 15 mL). The
combined organic layers were dried (MgSO4) and filtered, and
the solvent was evaporated in vacuo. The residue was dis-
solved in benzene, the solution was eluted from silica, and the
eluate was evaporated to dryness to furnish a white solid
Found: C, 65.04; H, 3.81; Ge, 30.1. Single crystals of 9 suitable
for X-ray structure determination were obtained from
a
concentrated chlorobenzene solution via slow evaporation of
the solvent.
tr a n s-1-(9-(10-P h en yl-9,10-d iger m a tr ip tycyl))-2-(9-(10-
p h en yl-10-ger m a -9-sila tr ip tycyl))eth en e (10). Over 5 min,
air was bubbled through a solution of 8 (0.1754 g, 0.369 mmol)
and 3a (0.1503 g, 0.368 mmol) in THF (5 mL), after which a
catalytic amount of H2PtCl6‚6H2O (0.005 g, 0.01 mmol) was
added. The reaction mixture was stirred at room temperature
for 18 h to furnish a clear brown solution and a white
precipitate. The solution was decanted, the residue was
washed with THF (1 × 5 mL), and the solvent was evaporated
in vacuo. The residue was dissolved in CHCl3 and eluted from
silica, and the eluate was evaporated to dryness. The residue
was washed with benzene (1 × 20 mL), after which it was dried
in vacuo to furnish a white solid (0.212 g, 0.240 mmol, 65%):
(0.022 g, 0.040 mmol, 19%): 1H NMR (400 MHz, CDCl3)20
δ
3
4
5
7.81 (m, J HH ) 7.3 Hz, J HH ) 1.3 Hz, J HH ) 0.7 Hz, 6H;
3
3
4
H(1,4,5,8,13,16)), 7.26 (m, J HH ) 7.6 Hz, J HH ) 7.3 Hz, J HH
) 1.3 Hz, 6H; H(2,3,6,7,14,15)), 0.39 (s, 18H; H(20,21,22,26,-
27,28)); 13C NMR (100 MHz, CDCl3) δ 143.0 (bs; C(4a,8a,9a,-
10a,11,12)), 131.9 (dt, 1J CH ) 159.8 Hz; C(1,4,5,8,13,16)), 127.9
1
3
mp >280 °C; H NMR (400 MHz, CDCl3)20 δ 8.38 (d, J HH
)
23.3 Hz, 1H; H(23 or 23′)), 8.20 (m, 4H; H(18,22,18′,22′)), 8.17
(d, 3J HH ) 23.3 Hz, 1H; H(23′ or 23)), 8.08 (dm, 3J HH ) 7.0 Hz,
3H; H(4,5,16 or 4′,5′,16′)), 8.01 (dm, 3J HH ) 6.8 Hz, 3H; H(4′,5′,-
(ddd, 1J CH ) 159.0 Hz, 2J CH ) 1.8 Hz, 3J CH ) 6.9 Hz; C(2,3,6,7,-
1
3
14,15)), 122.6 (s; C(17,23)), 97.6 (s; C18,24)), 0.0 (q, J CH
)
16′ or 4,5,16)), 7.81 (dm, J HH ) 7.0 Hz, 3H; H(1,8,13 or 1′,8′,-
3
120.0 Hz; C(20,21,22,26,27,28)). Attempts to obtain an ana-
lytically pure sample of 4 suitable for elemental analysis were
unsuccessful.
13′)), 7.80 (dm, J HH ) 7.1 Hz, 3H; H(1′,8′,13′ or 1,8,13)), 7.70
(m, 6H; H(19,20,21,19′,20′,21′)), 7.32 (m, 6H; H(3,6,15,3′,6′,-
15′)), 7.28 (m, 6H; H(2,7,14,2′,7′,14′)); 13C NMR (100 MHz,
2
3
9,10-Diet h yn yl-9,10-d ih yd r o-9,10-d iger m a -9,10[1′,2′]-
ben zen oa n th r a cen e (6). Compound 6 was prepared from a
solution of KOH (0.023 g, 0.5 mmol) in H2O (0.5 mL) and a
solution of 5 (0.009 g, e0.016 mmol) in THF (1 mL) as
described for 8. The crude product obtained after column
chromatography (0.008 g) was subjected to preparative TLC
(silica gel 60 F254, n-hexane/EtOAc (80:20), Rf 0.66) to furnish
a white solid (0.005 g, 0.011 mmol, 71%): 1H NMR (400 MHz,
CDCl3) δ 148.4 (dt, J CH ) 3.5 Hz, J CH ) 7.7 Hz; C(4a,10a,11
or 8a,9a,12 or 4a′,10a′,11′ or 8a′,9a′,12′)), 146.1 (d, 1J CH ) 142.8
Hz; C(23 or 23′)), 145.5 (dt, 2J CH ) 3.2 Hz, 3J CH ) 6.6 Hz; C(4a,-
10a,11 or 8a,9a,12 or 4a′,10a′,11′ or 8a′,9a′,12′)), 145.2 (bt, 3J CH
) 7.1 Hz; C(4a,10a,11 or 8a,9a,12 or 4a′,10a′,11′ or 8a′,9a′,-
1
2
12′)), 143.7 (d, J CH ) 142.8 Hz; C(23′ or 23)), 141.6 (dt, J CH
3
) 4.7 Hz, J CH ) 6.8 Hz; C(4a,10a,11 or 8a,9a,12 or 4a′,10a′,-
11′ or 8a′,9a′,12′)), 136.2 (dm, 1J CH ) 159.2 Hz; C(18,22 or 18′,-
3
4
5
1
CDCl3)20 δ 7.83 (m, J HH ) 7.3 Hz, J HH ) 1.2 Hz, J HH ) 0.7
22′)), 136.1 (dm, J CH ) 159.1 Hz; C(18′,22′ or 18,22)), 132.7
Hz, 6H; H(1,4,5,8,13,16)), 7.28 (m, J HH ) 7.6 Hz, J HH ) 7.3
(dd, 1J CH ) 158.1 Hz, 3J CH ) 7.2 Hz; C(4,5,16 or 4′,5′,16′)), 132.6
(dd, 1J CH ) 159.3 Hz, 3J CH ) 7.3 Hz; C(1,8,13 or 1′,8′,13′)), 132.0
(dd, 1J CH ) 159.4 Hz, 3J CH ) 7.6 Hz; C(1′,8′,13′ or 1,8,13)), 131.8
(dd, 1J CH ) 162.4 Hz, 3J CH ) 6.6 Hz; C(4′,5′,16′ or 4,5,16)), 130.1
(dt, 1J CH ) 153.9 Hz; C(20 or 20′)), 130.1 (dt, 1J CH ) 153.0 Hz;
C(20′ or 20)), 129.7 (s; C(17 or 17′)), 129.4 (s; C(17′ or 17)),
129.0 (dd, 1J CH ) 162.8 Hz; C(19,21 or 19′,21′)), 129.0 (dd, 1J CH
3
3
4
Hz, J HH ) 1.2 Hz, 6H; H(2,3,6,7,14,15)), 2.99 (s, 2H; H(18,-
20)); 13C NMR (100 MHz, CDCl3) δ 142.9 (bs, J CH ) 2.6 Hz,
2
3J CH ) 7.9 Hz, J CH ) 7.4 Hz, J CH ) -1.5 Hz; C(4a,8a,9a,-
3
4
1
2
3
10a,11,12)), 132.2 (m, J CH ) 161.3 Hz, J CH ) 1.6 Hz, J CH
7.2 Hz, J CH ) -1.4 Hz; C(1,4,5,8,13,16)), 128.5 (m, J CH
158.9 Hz, J CH ) 1.6 Hz, J CH ) 1.1 Hz, J CH ) 7.1 Hz;
C(2,3,6,7,14,15)), 100.6 (d, 1J CH ) 239.8 Hz; C(18,20)), 76.1 (d,
2J CH ) 44.0 Hz; C(17,19)). Anal. Calcd for C22H14Ge2: C,
62.39; H, 3.33. Found: C, 61.63; H, 3.74.
)
)
4
1
2
2
3
1
) 160.1 Hz; C(19′,21′ or 19,21)), 127.5 (dd, J CH ) 159.3 Hz,
3J CH ) 6.6 Hz; C(3,6,15,2,7,14,2′,7′,14′)), 127.3 (dd, 1J CH ) 159.9
3
Hz, J CH ) 6.3 Hz; C(3′,6′,15′)). Anal. Calcd for C50H36Ge3Si:
C, 68.03; H, 4.11; Ge, 24.7; Si, 3.2. Found: C, 67.84; H, 4.09;
Ge, 23.8; Si, 3.1.
1,4-Bis(9-(10-p h en yl-9,10-d iger m a t r ip t ycyl))b u t a -1,3-
d iyn e (9). A solution of CuCl (0.0017 g, 0.017 mmol) and 8
(0.1593 g, 0.330 mmol) in pyridine (15 mL) was stirred for 1 h
at 80 °C while pure O2 was bubbled through the solution. A
clear green-blue solution and a fine white precipitate were
obtained. The solution was removed by decantation, and the
precipitate was washed with pyridine (2 × 5 mL), toluene (2
× 5 mL), and n-hexane (2 × 5 mL). The undissolved residue
was dried in vacuo to give a white solid (0.116 g, 0.122 mmol,
X-r a y Cr ysta llogr a p h ic Da ta for Dim er 9. X-ray data
were collected on an Enraf-Nonius CAD4T/rotating anode
diffractometer23 for a colorless transparent crystal mounted
with the inert oil technique and transferred into the cold
nitrogen stream. Numerical details have been collected in
Table 2.
Accurate cell dimensions were derived from setting angles
of 25 SET424 reflections. The unit cell was checked for possible
higher metrical symmetry.25 The reflection data were cor-
rected for absorption using the DELABS procedure as imple-
mented in PLATON.26 The structure was solved by direct
methods (SHELXS9727) and refined on F2 using SHELXL97.28
1
74%): mp >280 °C; H NMR (400 MHz, C6D5Br)20 δ 8.19 (m,
4
5
3J HH ) 7.4 Hz, J HH ) 1.3 Hz, J HH ) 0.6 Hz, 6H; H(4,5,16)),
3
4
4
5
8.12 (m, J HH ) 7.4 Hz, J HH ) 1.4 Hz, J HH ) 1.2 Hz, J HH
)
3
4
0.7 Hz, 4H; H(18,22)), 7.79 (m, J HH ) 7.4 Hz, J HH ) 1.2 Hz,
5J HH ) 0.6 Hz, 6H; H(1,8,13)), 7.64 (m, J HH ) 7.6 Hz, J HH
)
3
3
4
5
7.4 Hz, J HH ) 1.3 Hz, J HH ) 0.7 Hz, 4H; H(19,21)), 7.62 (m,
One of the terminal phenyl moieties is disordered over two
orientations and was refined with a disorder model. In
addition a disorder model for a chlorobenzene molecule of
crystallization was used. Hydrogen atoms were taken into
4
3
3J HH ) 7.6 Hz, J HH ) 1.2 Hz, 2H; H(20)), 7.31 (m, J HH ) 7.4
Hz, 3J HH ) 7.4 Hz, 4J HH ) 1.2 Hz, 6H; H(3,6,15)), 7.24 (m, 3J HH
) 7.4 Hz, J HH ) 7.4 Hz, J HH ) 1.3 Hz, 6H; H(2,7,14)); 13C
NMR (100 MHz, C6D5Br) δ 144.6 (bs; C(8a,9a,12)), 143.7 (bs;
C(4a,10a,11)), 136.4 (dt, 1J CH ) 159.9 Hz, 3J CH ) 7.1 Hz; C(18,-
3
4
(21) Budzelaar, P. H. M. gNMR; Ivorysoft, Amsterdam, The Neth-
erlands, 1992.
(22) Castellano, S.; Bothner-By, A. A. J . Chem. Phys. 1964, 41, 3863.
(23) Enraf-Nonius CAD-4 Software, Version 5; Enraf Nonius, Delft,
The Netherlands, 1989.
(24) De Boer, J . L.; Duisenberg, A. J . M. Acta Crystallogr. 1984,
A40, C-410.
(25) LePage, Y. J . Appl. Crystallogr. 1987, 20, 264.
(26) Spek, A. L. Acta Crystallogr. 1990, A46, C-34.
1
3
22)), 132.8 (dd, J CH ) 159.6 Hz, J CH ) 7.1 Hz; C(1,8,13)),
1
3
132.6 (dd, J CH ) 161.0 Hz, J CH ) 7.3 Hz; C(4,5,16)), 130.6
1
3
1
(dt, J CH ) 160.5 Hz, J CH ) 7.4 Hz; C(20)), 129.4 (dd, J CH
)
3
160.3 Hz, J CH ) 6.8 Hz; C(19,21)), 129.1 (s; C(17)), 128.3(dd,
1J CH ) 158.8 Hz, J CH ) 8.4 Hz; C(2,7,14)), 128.2 (dd, J CH
)
3
1
3
161.0 Hz, J CH ) 6.8 Hz; C(3,6,15)), 94.9 (s; C(23)), 75.8 (s;
C(24)). Anal. Calcd for C52H34Ge4: C, 65.80; H, 3.61; Ge, 30.6.

1768 Organometallics, Vol. 17, No. 9, 1998
Dam et al.
account at calculated positions riding on their carrier atoms.
All geometric calculations and the ORTEP illustration were
done with PLATON.26
Chemical Research (SON) with financial aid from The
Netherlands Organization for Scientific Research (NWO).
Su ppor tin g In for m ation Available: Tables giving atomic
coordinates, thermal parameters, and bond distances and
angles for 9 (16 pages). Ordering information is given on any
current masthead page.
Ack n ow led gm en t. This work was supported in part
(M.A.D. and A.L.S.) by The Netherlands Foundation for
(27) Sheldrick, G. M. SHELXS97, Program for Crystal Structure
Solution; University of Go¨ttingen, Go¨ttingen, Germany, 1997.
(28) Sheldrick, G. M. SHELXL97, Program for Crystal Structure
Refinement; University of Go¨ttingen, Go¨ttingen, Germany, 1997.
OM980073F