α,ω-Bis(trialkynyltin) compounds with a linear or cross-shaped spacer

Article abstract of DOI:10.1021/om070078p

The preparation of arylene-, alkylene-, or dimethylenediphenyl-bridged bis(trichlorotin) compounds with two or three phenyl rings from the reaction of the corresponding hexacyclohexyl derivatives with tin tetrachloride is described. Hexachlorides with mixed aryl - alkyl bridges were prepared in the same way. When arylene-bridged ditins were substituted on aryl rings with alkoxy groups, it was necessary to use hexamethyl derivatives instead of the cyclohexyl compounds to obtain the corresponding hexachlorides. In these compounds, weak inter- and/or intramolecular interactions were detected by X-ray analysis. The ditin hexachlorides were transformed into the corresponding hexaalkynyl derivatives, precursors for hybrid materials.

Full text of DOI:10.1021/om070078p

3908
Organometallics 2007, 26, 3908-3917
Articles
r,ω-Bis(trialkynyltin) Compounds with a Linear or Cross-Shaped
Spacer
Hicham Elhamzaoui,† Bernard Jousseaume,*,† Thierry Toupance,† and Hassan Allouchi§
UniVersite´ Bordeaux 1, CNRS, UMR 5255, ISM, Mate´riaux, 351 Cours de la Libe´ration, 33405 Talence,
France, and Laboratoire de Chimie Physique SPOT, EA 3857, Faculte´ de Pharmacie, UniVersite´ de Tours,
31 AVenue Monge, 37200 Tours, France
ReceiVed January 26, 2007
The preparation of arylene-, alkylene-, or dimethylenediphenyl-bridged bis(trichlorotin) compounds
with two or three phenyl rings from the reaction of the corresponding hexacyclohexyl derivatives with
tin tetrachloride is described. Hexachlorides with mixed aryl-alkyl bridges were prepared in the same
way. When arylene-bridged ditins were substituted on aryl rings with alkoxy groups, it was necessary to
use hexamethyl derivatives instead of the cyclohexyl compounds to obtain the corresponding hexachlorides.
In these compounds, weak inter- and/or intramolecular interactions were detected by X-ray analysis. The
ditin hexachlorides were transformed into the corresponding hexaalkynyl derivatives, precursors for hybrid
materials.
For the past few years, research on hybrid materials consti-
including an aromatic ring is used.4 With more flexible alkylene
chains as spacers, it is necessary to include functional groups
able to increase the interchain interactions by formation of
hydrogen bonds, such as urea groups.5 Tin is a metal that forms
carbon-metal bonds that are stable toward hydrolysis, which
enables the preparation of hybrid materials.6 However, due to
the difficulty in obtaining the functional tin trialkoxides, which
are the traditional starting materials for organosilicon hybrid
materials, more accessible trialkynyltin derivatives were used
instead.7 Compounds containing two tin groups separated by
short spacers can be prepared,8 and they enable the synthesis
tutes a growing field in which organometallic chemistry has an
important place. In class 2 hybrid materials,1 the organic and
the inorganic components are linked through covalent bonds,
which requires the design and development of appropriate
synthetic schemes necessary for the preparation of suitable
precursors for these materials. Main approches to hybrid
materials are based on silicon derivatives since silicon-carbon
bonds of various types usually are stable toward sol-gel
conditions, in which acidic, basic, or fluoride-catalyzed hy-
drolyses are used. Some functional groups can even be
incorporated into the organic part of the hybrid materials and
remain unchanged in the hybrid material after the whole
(4) (a) Boury, B.; Corriu, R. J. P. Chem. Commun. 2002, 795. (b) Boury,
B.; Corriu, R. J. P.; Le Strat, V.; Delord, P.; Nobili, M. Angew. Chem., Int.
Ed. 1999, 38, 3172. (c) Ben, F.; Boury, B.; Corriu, R. J. P. AdV. Mater.
2002, 14, 1081.
(5) (a) Moreau, J. J. E.; Vellutini, L.; Wong Chi Man, M.; Bied, C. J.
Am. Chem. Soc. 2001, 123, 1509. (b) Moreau, J. J. E.; Vellutini, L.; Wong
Chi Man, M.; Bied, C.; Bantignies, J.-L.; Dieudonne´, P.; Sauvajol, J.-L. J.
Am. Chem. Soc. 2001, 123, 7957.
1
preparative process, hydrolysis, aging, and drying. It was
reported recently that the disilylated compounds proved to be
excellent precursors for various types of microporous or
mesoporous silicas.2 In that case, with aliphatic spacers, the
duration of the gelification process is a function of the length
of the spacer since medium-size spacers induce intramolecular
cyclization reactions leading to soluble oligomers. This is not
the case with aromatic, ethylenic, or acetylenic spacers, where
the rigid rod-like spacer between the silicon atoms makes such
cyclizations impossible and enables the preparation of gels even
at very low concentrations of disilylated compounds.3 These
hybrid materials are often self-organized, which is detected
either by birefringence studies or by X-ray data, when a spacer
(6) (a) Ribot, F.; Banse, F.; Sanchez, C.; Lahcini, M.; Jousseaume, B.
J. Sol-Gel Sci. Tech. 1997, 8, 529. (b) Angiolini, L.; Caretti, D.; Carlini,
C.; Jordens, F.; Jousseaume, B.; Niesel, T. J. Inorg. Organomet. Polym.
1998, 8, 48. (c) Jaumier, P. ; Jousseaume, B.; Riague, H.; Toupance,
T.; Lahcini, M. In Hybrid Organic/Inorganic Materials; Laine, R. M.,
Sanchez, C., Giannelis, E., Brinker, C. J., Eds.; MRS, 2000; Vol. 628, p
CC12.
(7) (a) Jousseaume, B.; Lahcini, M.; Rascle, M.-C.; Sanchez, C.; Ribot,
F. Organometallics 1995, 14, 685. (b) Jousseaume, B.; Lahcini, M.; Fouquet,
E.; Barbe, B. J. Org. Chem. 1994, 59, 8292. (c) Biesemans, M.; Willem,
R.; Damoun, S.; Geerlings, P.; Lahcini, M.; Jaumier, P.; Jousseaume, B.
Organometallics 1996, 15, 2237. (d) Jaumier, P.; Jousseaume, B.; Tiekink,
E. R. T. Biesemans, M.; Willem, R. Organometallics 1997, 16, 5124.
(e) Biesemans, M.; Willem, R.; Damoun, S.; Geerlings, P.; Tiekink, E. R.
T.; Lahcini, M.; Jaumier, P. ; Jousseaume, B. Organometallics 1998, 17,
90. (f) Jaumier, P.; Jousseaume, B.; Lahcini, M.; Ribot, F.; Sanchez, C. J.
Chem. Soc., Chem. Commun. 1998, 369. (g) Jaumier, P.; Jousseaume, B.
Main Group Met. Chem. 1998, 21, 325. (h) Lahcini, M.; Jaumier, P.;
Jousseaume, B. Angew. Chem., Int. Ed. 1999, 32, 402. (i) Willem, R.;
Biesemans, M.; Jaumier, P.; Jousseaume, B. J. Organomet. Chem. 1999,
572, 233.
* Corresponding author. E-mail: b.jousseaume@ism.u-bordeaux1.fr.
† Universite´ Bordeaux 1.
§ Universite´ de Tours.
(1) Gomez-Romero, P.; Sanchez, C. Functional Hybrid Materials; Wiley-
VCM: Weinheim, Germany, 2003.
(2) (a) Shea, K. J.; Loy, D. A. Chem. Mater. 2001, 13, 3306. (b) Shea,
K. J.; Loy, D. A. Acc. Chem. Res. 2001, 34, 707. (c) Loy, D. A.; Shea, K.
J. Chem. ReV. 1995, 95, 1431. (d) Cerveau, G.; Corriu, R. J. P.; Framery,
E. Chem. Mater. 2001, 13, 3373. (e) Corriu, R. J. P. Angew. Chem., Int.
Ed. 2000, 39, 1376.
(8) Jousseaume, B.; Riague, H.; Toupance, T.; Lahcini, M.; Mountford,
P.; Tyrrell, B. R. Organometallics 2002, 21, 4590.
(3) Chujo, Y.; Ihara, S.; Saegusa, T. Macromolecules 1993, 26, 5681.
10.1021/om070078p CCC: $37.00 © 2007 American Chemical Society
Publication on Web 06/30/2007

R,ω-Bis(trialkynyltin) Compounds
Organometallics, Vol. 26, No. 16, 2007 3909
Scheme 1. Preparation of 4,4′-Bis(tricyclohexyltin)biphenyl
(1) and 4,4′′-Bis(tricyclohexyltin)-1,1′:4′,1′′-terphenyl (2)
Scheme 2. Preparation of
4,4′-Bis(tricyclohexyltinmethyl)biphenyl (3)
Figure 1. Molecular structure of 2. Thermal ellipsoids are shown
at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C1 2.147(12), Sn1-
C43 2.161(13), Sn1-C49 2.166(9), Sn1-C37 2.169(14), C1-Sn1-
C43 101.6(5), C1-Sn1-C49 109.3(4), C43-Sn1-C49 112.7(5),
C1-Sn1-C37 107.5(6), C43-Sn1-C37 109.1(5), C49-Sn1-C37
115.6(5), C3-C4-C7-C8 30.1(1).
of self-organized hybrid materials9 in which layers of tin oxide
are separated by the autoassembled organic spacers. However
the starting materials used were limited to examples with short
connected chains between the metals. In order to broaden the
scope of the available precursors, we present here the synthesis
of alkyl, aromatic, or benzylic R,ω-ditin hexaalkynyls in which
the tin atoms are separated by two or three phenyl rings.
Moreover, we report also the preparation and the structural
characterization of cross-shaped aromatic R,ω-ditin hexaalkynyls
with one or three benzene rings substituted by long alkoxy
groups.
Figure 2. Molecular structure of 3. Thermal ellipsoids are shown
at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C1 2.147(12), Sn1-
C7 2.182(7), Sn1-C19 2.156(9), Sn1-C13 2.180(9), C1-Sn1-
C19 110.2(5), C1-Sn1-C13 115.1(4), C13-Sn1-C19 110.5(4),
C1-Sn1-C7 109.0(4), C7-Sn1-C19 103.3(3), C7-Sn1-C13
108.1(3), Sn1-C19-C20 117.5(6), Sn1-C19-C20-C21 77.0(1).
Results and Discussion
method that led successfully to simpler compounds. This strategy
consists of the preparation of hexacyclohexylditins via di-
Grignard reagents and their cleavage with tin tetrachloride to
obtain the corresponding hexachlorides, followed by the alky-
nylation of these polychlorides with alkynyllithiums. However
the previously described way was not very satisfactory since
the coupling of 4,4′-di(bromomagnesio)biphenyl or 4,4′′-di-
(bromomagnesio)-1,1′:4′,1′′-terphenyl with tricyclohexyltin chlo-
ride led to very poor yields of the corresponding ditin
derivatives. Fortunately, the corresponding dilithio reagents were
more soluble and enabled the isolation of the ditin compounds
in satisfactory yields. In order to measure the distance between
the tin atoms, necessary for the study of the derived hybrid
materials, a structural study of 4,4′′-bis(tricyclohexyltin)-1,1′:
4′,1′′-terphenyl (2) was conducted. Suitable crystals were grown
from a toluene solution of 2. The asymmetric unit of the crystal
structure is illustrated in Figure 1. The molecule in the solid
state is characterized by non-coplanar phenyl rings, with the
central one twisted by about 30° relative to each of the other
rings. In the case of p-terphenyl, crystallographic studies reveal
a similar coplanar relationship between the remote rings, with
the central ring twisted by about 13°.17 In the case of substituted
p-terphenyl the central ring can be twisted up to about 31°.18
The cyclohexyl rings are nearly staggered with respect to the
Sn-Sn axis, the dihedral angles CCyclohexyl-Sn-Sn-CCyclohexyl
varying from 50° to 78°. Each tin atom is in a tetrahedral
environment and is slightly outside of the plane formed by the
Many methods for the preparation of R,ω-ditin derivatives
have been reported up to now. The first one involves the
coupling of an R,ω-Grignard or an R,ω-dilithium reagent with
a triorganotin halide or the coupling of a triorganotinmetal with
an R,ω-dihalide. It can be successfully used when the chain
separating the tin atoms is either of aliphatic10,11 or aromatic
type.12,13 The second method, which is useful when dimetallic
species are not available, is conducted under milder conditions,
as it involves the palladium-catalyzed14 or uncatalyzed15 addition
of hexaorganoditins to unsaturated compounds. Finally, the
hydrostannation of unsaturated compounds is also very conve-
nient to prepare compounds containing two separated tin atoms,
as this addition reaction is highly regiospecific and thus leads
to linear compounds.16
To prepare hexaalkynylditins where the tin atoms are
separated by two or three aromatic rings, we employed the
(9) Elhamzaoui, H.; Jousseaume, B.; Riague, H.; Toupance, T.; Dieud-
onne, P.; Zakri, C.; Maugey, M.; Allouchi, H. J. Am. Chem. Soc. 2004,
126, 8130.
(10) Bulten, E. J.; Budding, H. A. J. Organomet. Chem. 1976, 110, 167.
(11) Traylor, T. G.; Koermer, G. S. J. Org. Chem. 1981, 46, 3651.
(12) (a) Boue, S.; Gielen, M.; Nasielski, J. Bull. Soc. Chim. Belg. 1967,
76, 559. (b) Juara, K. L.; Hundal, H. S.; Handa, R. D. Indian J. Chem.
1967, 5, 211.
(13) Wursthorn, K. R.; Kuivila, H. G.; Smith, G. F. J. Am. Chem. Soc.
1977, 100, 2779.
(14) Mitchell, T. M.; Amamria, A.; Killing, H.; Rutshow, D. J.
Organomet. Chem. 1986, 304, 257.
(15) Beg, M. A. A.; Clark, H. C. Chem. Ind. 1962, 140.
(16) Van der Kerk, G. J. M.; Noltes, J. G. J. Appl. Chem. 1957, 7, 366.
(17) Baudour, J. L. Acta Crystallogr. 1991, B47, 935.
(18) Xu, J.; Coˆte´, A. P.; Chen, B. Acta Crystallogr. 2004, E60, 1697.

3910 Organometallics, Vol. 26, No. 16, 2007
Elhamzaoui et al.
Scheme 4. Preparation of
2′,5′-Dioctyloxy-4,4′′-bis(trimethyltin)-1,1′:4′,1′′-terphenyl (7)
Figure 3. Molecular structure of 4. Thermal ellipsoids are shown
at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C12 2.1509(27),
Sn1-C13 2.1378(28), Sn1-C14 2.1408(30), Sn1-C2 2.1461(20),
C12-Sn1-C13 111.52(10), C12-Sn1-C14 109.38(11), C13-
Sn1-C14 110.36(11), C2-Sn1-C12 109.92(9), C2-Sn1-C13
106.14(9), C2-Sn1-C14 113.44(9).
Scheme 5. Preparation of
4,4′-Bis(4-tricyclohexyltinbutyl)biphenyl (8)
We encountered the same difficulty for the preparation of
aromatic ditin compounds substituted with long side arms as
for the preparation of 1 and 2, the use of a di-Grignard reagent
leading only to poor results. However, the coupling of the
corresponding dilithium reagents with tricyclohexyl- and tri-
methyltin chloride enabled the isolation of the ditin derivatives
in satisfactory yields. The crystal structures of compounds 4
(Figure 3), 5 (Figure 4), and 6 (Figure 5) were determined. 5
shows a center of symmetry and the tins are in the same slightly
distorted tetrahedral environment as in 3. They lie in the plane
of the aromatic ring. The long tin-oxygen distance, 3.21 Å,
forbids any eventual coordination of the metals by the oxygen
atoms. The cyclohexyl groups are in an almost perfect staggered
position with respect to the Sn-Sn axis, the dihedral angles
CCyclohexyl-Sn-Sn-CCyclohexyl varying from 59° to 63°. The
alkoxyl chains present an all-trans conformation and are close
to being coplanar with the plane of the aromatic ring (dihedral
angle: 3.8°). The crystal structures of 5 and 6 are nearly the
same, except that the steric release around the tin atoms
introduced by changing bulky cyclohexyl groups by smaller
methyl groups allows a closer contact between tin and oxygen
atoms, 3.09 Å in 4 and 3.06 Å in 5 instead of 3.21 Å in the
case of 6. The side chains are in an all-trans conformation. They
are slightly more twisted (6.5°) in 6 than in 5, but the terminal
methyl groups lie out of the chain plane, probably to avoid too
close contacts with the methyl groups linked to the tin atom of
another molecule. The distance between the tins in 4 and 6 is
7.11 Å (7.14 Å in 5), and the distance between the terminal
carbon atoms of the chains is 25.22 Å in 4, 24.51 Å in 5, and
44.07 Å in 6.
Figure 4. Molecular structure of 5. Thermal ellipsoids are shown
at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C10 2.142(5), Sn1-
C3 2.148(4), Sn1-C8 2.172(4), Sn1-C11 2.180(5), C10-Sn1-
C3 111.51(18), C10-Sn1-C8 109.66(19), C3-Sn1-C8 107.96-
(16), C10-Sn1-C11 113.2(2), C3-Sn1-C11 103.91(17), C8-
Sn1-C11 110.40(19).
Scheme 3. Preparation of
2,5-Dialkyloxy-1,4-bis(trialkyltin)benzenes (4-6)
terminal rings (aromatic plane-C1-Sn: 5.6°). The distance
between the tins is 15.77 Å.
4,4′-Bis(tricyclohexyltinmethyl)biphenyl (3) was successfully
prepared by a Barbier reaction, since lithium or magnesium
reagents derived from 4,4′-bis(chloromethyl)biphenyl are not
stable. Thus, the treatment of a THF solution of 4,4′-bis-
(chloromethyl)biphenyl and tricyclohexyltin chloride with mag-
nesium led to 3 in good yield. The X-ray diffraction study of a
monocrystal of 3 revealed a centrosymmetric structure with
coplanar aromatic rings (Figure 2). The tricyclohexyltin groups
are in the anti position, in contrast to that observed in its
hexaphenyl analogue with one aromatic ring, where the triph-
enyltin groups are in the syn position, probably because of a
more favorable crystal packing.19 The tin environment is normal
for a tricyclohexyl derivative, and the distance between the tins
is 12.78 Å.
When the spacer between the tin atoms was of a p-terphenyl
type, with the central ring substituted with two alkoxyl chains,
the use of the corresponding di-Grignard reagent was shown to
be more advantageous than that of the corresponding dilithium
reagent. The Grignard route led to the ditin compound 7 with
an 87% yield. It is a centrosymmetric molecule in the solid state
(19) Thodupunoori, S. K.; Alamudun, I. A.; Cervantes-Lee, F.; Gomez,
F. D.; Carrasco, Y. P.; Pannell, K. J. Organomet. Chem. 2006, 691, 1790.

R,ω-Bis(trialkynyltin) Compounds
Organometallics, Vol. 26, No. 16, 2007 3911
Figure 5. Molecular structure of 6. Thermal ellipsoids are shown at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C20 2.135(2), Sn1-C21 2.138(2), Sn1-C18 2.1466(18), Sn1-C22 2.147(2), C20-Sn1-
C21 110.75(9), C20-Sn1-C18 109.92(8), C21-Sn1-C18 110.46(8), C20-Sn1-C22 109.18(9), C21-Sn1-C22 110.08(9), C18-Sn1-
C22 106.35(8).
Figure 8. Intermolecular bonding in 12.
Scheme 6. Preparation of Linear Ditin Hexachlorides
(9-12)
Figure 6. Molecular structure of 7. Thermal ellipsoids are shown
at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C20 2.128(2), Sn1-
C21 2.139(2), Sn1-C22 2.143(2), Sn1-C14 2.1483(17), C20-
Sn1-C21 113.05(9), C20-Sn1-C22 110.94(9), C21-Sn1-C22
107.73(10), C20-Sn1-C14 107.08(8), C21-Sn1-C14 107.80(8),
C22-Sn1-C14 110.19(8), C8-C5-C3-C4 39.4(2).
the diene with an excess of stannane at 130 °C for 7 days in
the presence of AIBN (portionwise added during the reaction)
led to 8 in a good yield (60%). Then the bis(tricyclohexylated)
compounds 1-3, 5, and 8 were treated with 1 equiv of tin tetra-
chloride at 70 °C (20 °C for 8) for 1 day (3 days for 8), which
resulted in the complete replacement of the tricyclohexyl-
tin groups by trichlorotin groups. Extraction with a mixture
pentane/acetonitrile or washing with pentane both led to the
Figure 7. Molecular structure of 12. Thermal ellipsoids are shown
at the 50% probability level. Hydrogen atoms are omitted for clarity.
bis(trichlorotin) compounds in high yields, except in the case
of 5, where the hexachloride was very soluble in pentane and
Selected distances (Å) and angles (deg): Sn1-Cl1 2.518(3), Sn1-
could not be separated from tricyclohexyltin chloride. We thus
Cl2 2.218(2), Sn1-Cl3 2.179(3), Sn1-C4 2.221(5), Cl3-Sn1-
had to find another way to prepare the very lipophilic ditin
Cl2 111.56(11), Cl3-Sn1-C4 120.1(3), Cl2-Sn1-C4 109.9(2),
hexachlorides. It was anticipated that a secondary product with
Cl3-Sn1-Cl1 85.85(12), Cl2-Sn1-Cl1 95.02(12), C4-Sn1-Cl1
a very low boiling point could be separated from the heavy
hexachlorides in conditions mild enough not to decompose them.
We thus treated the hexamethylated ditins with an excess of
tin tetrachloride (4 equiv/Sn) at 120 °C for a few hours and
then distilled the mixture of unreacted tin tetrachloride and
methyltin chlorides under high vacuum. The crude hexachlorides
were pure enough to be used in the next step without further
purification. The crystal structure of 12 was determined by X-ray
diffraction (Figure 7). The molecule has a center of symmetry
and the tin atoms are in a slightly distorted tetrahedral
environment, which is normal for an alkyltin trichloride. The
130.8(3).
(Figure 6). The aromatic rings are much more twisted (39.4°)
than in 2, and the side chains are almost coplanar. In the crystal,
the molecules are arranged in such a manner that all the
corresponding planes are parallel. The distance between the tins
is 15.77 Å, and the distance between the terminal carbon atoms
of the chains is 25.09 Å.
As 4,4′-di(but-3-enyl)biphenyl was found readily available
from the dimerization of 1-bromo-4-(but-3-enyl)benzenyl mag-
nesium in the presence of titanium tetrachloride,20 the radical
addition of tricyclohexylstannane to the R,ω-diene was used to
obtain the corresponding ditin compound. Thus, treatment of
(20) Inoue, A.; Kitagawa, K.; Shinokubo, H.; Oshima, K. Tetrahedron
2000, 56, 9601.

3912 Organometallics, Vol. 26, No. 16, 2007
Elhamzaoui et al.
of the side chains. The angle between the Sn-Sn axis and the
side chain ranges from 80° and 81° in 4 and 5, respectively, to
28.6° in 13. This different behavior could be due to the angle
made by the Sn-C2 bond and the O4-C3 bond, which is
smaller in 13 than in its methylated analogue 6, which thus
brings closer the chain from the tin atom. Another possible
reason could be the existence of weak interactions between the
chlorine atom Cl2 and the hydrogen atom H7A, which are
separated by 3.08 Å. The distance between the terminal carbon
atoms of the chains is 23.52 Å.
Scheme 7. Preparation of Cross-Shaped Ditin
Hexachlorides (13-15)
The molecular structure of 14 is roughly identical to that of
13, with fully extended side arms and a distorted tetrahedral
environment of tin atoms. Then alkynylation of the hexachlo-
rides was performed with a stoichiometric amount of propy-
nyllithium at low temperature to form the corresponding
hexaalkynylditins in a good yield as crystalline solids.
The molecular structure of 20 is depicted in Figures 11 and
12. It shows a center of symmetry. The tin atoms are in a slightly
distorted tetrahedral environment, not so different from what
has been observed in 4, with a shorter Sn-O distance, 2.96 Å
instead of 3.09 Å, which can be explained by the higher
electrophilic character of the tin due to the electroattractive
propynyl groups. However, this distance is longer than when
the tin is substituted by chlorine atoms as in 13, 2.86 Å. It is
worth noting the regular variation of the tin-oxygen bond
distance and of the Sn1-C2-C3 and O4-C5-C6 angles (see
Table 1) with the electronegativity of the substituents of the tin
atoms in 5, 6, 13, 14, and 20. 119Sn NMR proved to be a very
more prominent feature of this structure is the folded conforma-
tion of the butylene chains, which are not completely extended,
whereas the structures of ditin hexachlorides with the metal
atoms separated by an alkylene chain are linear. However, the
tin atoms and the last carbon of the chains are in the plane of
the aromatic rings. The tin-tin distance is shorter (16.41 Å)
than expected (21.21 Å) if the chains were completely extended,
which results from this folding. Such an arrangement could be
explained by the existence of stabilizing interactions between
the Cl1 and the H4B of a neighboring molecule, as the distance
between these atoms is 2.84 Å and the angle C4-H4B-Cl1 is
140° (Figure 8). These atoms are part of an eight-membered
ring21 in a pseudochair conformation formed with two chlorine,
two hydrogen, two carbon, and two tin atoms. Such close
contacts are shorter than OH-Cl22 (3.40 Å) or NH-Cl23 (3.12
Å) interactions in titanium complexes but longer than CH-Cl
interactions in chloroform-solvated platinum24 (2.76 Å) or than
charge-assisted CH-Cl interactions in gold25 (2.59 Å) com-
plexes. The value of the C4-H4B-Cl1 angle (140°) shows that
this interaction can be described as a hydrogen bond rather than
as a van der Waals contact.26 As a consequence, the Sn1-Cl1
bond is considerably lengthened. It measures 2.51 Å, whereas
the length of other Sn-Cl bonds are 2.18 and 2.22 Å,
respectively.
The molecular structure of 13 is shown in Figure 9. It differs
from the corresponding trialkylated compounds 4 and 5 by a
shorter tin-oxygen distance, 2.86 Å instead of 3.09 and 3.21
Å, respectively, indicating the existence of a weak coordination
bond between both atoms, disfavored by the formation of a
sterically demanding four-bond ring. The difference between
the sum of the angles formed by the equatorial bonds and the
sum of the angles formed by the axial bonds is 22.6° (0° for a
tetrahedron, 90° for a trigonal bipyramid).27 The tin lies 0.60
Å above the C2-Cl1-Cl2 plane. The geometry of the tin can
thus be considered as that of a distorted tetrahedron. The
structure of 13 also differs by a significantly different orientation
7
powerful tool to study weak coordination of tin in solution.
The 119Sn chemical shifts of 5, 6, 13, 14, and 20 were thus
compared to the 119Sn chemical shifts of their unsubstituted
analogues. However, while upfield shifts were expected, only
inconclusive differences were found. The side chains are not
coplanar with the aromatic ring, as they are in the hexamethy-
lated 4. From C5, the plane of the chain is almost perpendicular
to the aromatic ring. Moreover, the axis of the chain is out of
the aromatic plane, almost parallel to an alkynyl group, and
forms an angle of 64° with the aromatic ring. This position of
the chain could be explained by the existence of a favorable
interaction between the hydrogen atom H8B with the π electrons
of one of the triple bonds. The distance between H8B and the
triple bond is 3.24 Å, and the angle C8-H8B-triple bond is
141°. Such weak bonds have already been described in
alkynylmetallic compounds where the metal makes the triple
bond more nucleophilic.28 It usually involves acidic hydrogen
atoms, like those of chloroform,29 cyclopentadienes,30 or
alkynes,31 with distances varying from 2.33 to 2.61 Å.
Compounds 16-22 were subsequently hydrolyzed in THF,
yielding transparent or opaque gels, depending on the hydrolysis
conditions, which were then thermolyzed, forming high surface
area mesoporous tin oxide.32
In conclusion, we have developed synthetic methods for the
preparation of ditin compounds where the organic groups
(28) Fan, M.-F.; Lin, Z.; McGrady, J. E.; Mingos, M. P. J. Chem. Soc.,
Perkin Trans. 2 1996, 563.
(29) Mu¨ller, T. E.; Mingos, M. P.; Williams, D. J. J. Chem. Soc., Chem.
Commun. 1994, 1787.
(30) Steiner, T.; Tamm, M. J. Organomet. Chem. 1998, 570, 235.
(31) Steiner, T. J. Chem. Soc., Chem. Commun. 1995, 95.
(32) (a) Toupance, T.; El Hamzaoui, H.; Jousseaume, B.; Riague, H.;
Saadeddin, I.; Campet, G.; Bro¨tz, J. Chem. Mater. 2006, 18, 6364. (b)
Boutet, S.; Jousseaume, B.; Toupance, T.; Biesemans, M.; Willem, R.;
Labrugere, C.; Delattre, L. Chem. Mater. 2005, 17, 1803. (c) Vilaca, G.;
Jousseaume, B.; Mahieux, C.; Toupance, T.; Belin, C.; Cachet, H.; Bernard,
M.-C.; Vivier, V. AdV. Mater. 2006, 18, 1073. (d) Elhamzaoui, H.;
Jousseaume, B.; Toupance, T.; Zakri, C.; Maugey, M. Langmuir 2007, 23,
785.
(21) Baldovino-Pantaleon, O.; Morales-Morales, D.; Hernandez-Ortega,
S.; Toscano, R. A.; Valdes-Martinez, J. Cryst. Growth Des. 2007, 7, 117.
(22) Bastiansen, O.; Fernholt, L.; Hedberg, K.; Seip, R. J. Am. Chem.
Soc. 1985, 107, 7836.
(23) Guzei, I. A.; Winter, C. H. Inorg. Chem. 1997, 36, 4415.
(24) Jones, P. G.; Schmutzler, R.; Vogt, R. Acta Crystallogr. 2002, E58,
m476.
(25) Freytag, M.; Jones, P. G. Chem. Commun. 2000, 277.
(26) (a) Aullon, G.; Bellamy, D.; Guy Orpen, A.; Brammer, L.; Bruton,
E. A. Chem. Commun. 1998, 653. (b) Thallapally, P. K.; Nangia, A.
CrystEngComm 2001, 3, 114.
(27) Kolb, U.; Dra¨ger, M.; Jousseaume, B. Organometallics 1991, 10,
2737.

R,ω-Bis(trialkynyltin) Compounds
Organometallics, Vol. 26, No. 16, 2007 3913
Figure 9. Molecular structure of 13. Thermal ellipsoids are shown at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C2 2.091(3), Sn1-Cl1 2.2978(11), Sn1-Cl2 2.3055(10), Sn1-Cl3 2.3225(10), C2-Sn1-
Cl1 116.64(10), C2-Sn1-Cl2 118.26(11), Cl1-Sn1-Cl2 104.06(4), C2-Sn1-Cl3 107.57(10), Cl1-Sn1-Cl3 104.13(4), Cl2-Sn1-Cl3
104,75(4).
Figure 10. Molecular structure of 14. Thermal ellipsoids are shown at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C8 2.096(3), Sn1-Cl2 2.2962(10), Sn1-Cl1 2.3011(10), Sn1-Cl3 2.3242(10), C8-Sn1-
Cl2 114.59(10), C8-Sn1-Cl1 119.21(10), Cl2-Sn1-Cl1 104.96(4), C8-Sn1-Cl3 108.04(10), Cl2-Sn1-Cl3 105.65(4), Cl1-Sn1-Cl3
103.06(4).
Scheme 8. Preparation of Hexapropynylditins (16-22)
Figure 11. Molecular structure of 20. Thermal ellipsoids are shown
at the 50% probability level. Hydrogen atoms are omitted for clarity.
Selected distances (Å) and angles (deg): Sn1-C11 2.073(2), Sn1-
C6 2.081(2), Sn1-C15 2.082(2), Sn1-C3 2.1068(19), C11-Sn1-
C6 106.49(9), C11-Sn1-C15 108.65(8), C6-Sn1-C15 108.07(8),
C11-Sn1-C3 116.28(8), C6-Sn1-C3 107.96(8), C15-Sn1-C3
109.10(8).
separating the tin atoms can be substituted or not with long
aliphatic chains. X-ray diffraction studies showed that weak tin-
oxygen interactions exist in the ditin derivatives with an oxygen
atom in the â-position from the tin atom, which results in the
formation of an unfavorable four-membered ring.
300 spectrometer (solvent CDCl3). Tin-hydrogen and tin-carbon
coupling constants are given in square brackets. Elemental analyses
Experimental Section
All reactions were carried out under a nitrogen atmosphere.
Pentane, THF, and diethyl ether were distilled from sodium
benzophenone ketyl prior to use. Acetonitrile was distilled over
CaH2. Tin tetrachloride was distilled before use. 1H, 13C, and 119Sn
NMR spectra were recorded on a Bruker AC 200, AC 250, or DPX
were performed by the “Service d’analyse du CNRS” at Vernaison,
France.
4,4′-Bis(tricyclohexyltin)biphenyl (1). A solution of 4,4′-
dibromobiphenyl (4 g, 12.8 mmol) in diethyl ether (400 mL) was
cooled to -78 °C with an ethanol/liquid N2 bath. With the addition

3914 Organometallics, Vol. 26, No. 16, 2007
Elhamzaoui et al.
2THF: C, 32.17; H, 3.24; O, 4.28; Cl, 28.49; Sn, 31.80. Found:
C, 30.81; H, 3.10; O, 5.23; Cl, 28.16; Sn, 31.45.
4,4′-Bis(triprop-1-ynyltin)biphenyl (16). A solution of n-
butyllithium (23.9 mL, 59.7 mmol) in hexane (2.5 M) was slowly
added to a solution of propyne (87.4 mmol) in toluene (55 mL) at
-78 °C. After 15 min stirring at room temperature, a solution of
4,4′-bis(trichlorotin)biphenyl (5 g, 8.3 mmol) in toluene (100 mL)
was added at -78 °C. The suspension was stirred at room
temperature for 12 h and then filtered on dry MgSO4 under dry
N2, and the toluene was evaporated to give 16 (3.1 g) as a white
1
solid. Mp: 250 °C dec. Yield: 60%. H NMR: δ 1.97 (s, 18H,
[15]), 7.6-7.8 (m, 8H, [73]). 13C NMR: δ 5.3 [16], 76.0 [934],
108.5 [193], 127.6 [80], 134.3, 136.1 [59], 142.6. 119Sn NMR: δ
-285.2 [931, 193]. Anal. Calcd for C30H24Sn2: C, 57.75; H, 4.20;
Sn, 38.05. Found: C, 57.08; H, 4.57; Sn, 38.22.
4,4′′-Bis(tricyclohexyltin)-1,1′:4′,1′′-terphenyl (2). A suspension
of 4,4′′-dibromo-1,1′:4′,1′′-terphenyl33 (10 g, 25.7 mmol) in diethyl
ether (425 mL) was cooled to -78 °C with an ethanol/liquid N2
bath. With the addition of tert-butyllithium (68.75 mL, 1.5 M in
pentane, 4 equiv) the white suspension turned yellow after 4 h under
stirring.34 The mixture was warmed to room temperature for 1 h.
It was cooled to -78 °C again, before adding a solution of
tricyclohexyltin chloride (20 g, 49.5 mmol) in THF (100 mL). After
30 min, the reaction was allowed to warm to room temperature.
After stirring for 72 h, the mixture was hydrolyzed with a saturated
solution of NH4Cl and extracted. The solvent was removed in vacuo,
and the resulting product was recrystallized from 2-methylbutan-
2-ol to give 2 (6.2 g) as a white solid. Mp: 250 °C dec. Yield:
Figure 12. Another view of 20.
Table 1. Tin-Oxygen Distances and O-C and Sn-C
Alignment in the Ditin Compounds 4, 5, 6, 13, 14, and 20
1
25%. H NMR: δ 1.1-2 (m, 66H), 7.5-7.65 (m, 8H), 7.69 (s,
4H). 13C NMR: δ 27.2 [344], 27.4, 29.5 [57], 32.5 [17], 126.5
[37], 127.5, 137.9 [26], 140.2, 140.24, 140.3. 119Sn NMR: δ
-101.5. Anal. Calcd for C54H78Sn2: C, 67.24; H, 8.15; Sn, 24.61.
Found: C, 67.99; H, 8.31; Sn, 22.71.
dSn-O Sn1-C2-C3 O4-C5-C6
compound
R1
R2
(Å)
(deg)
(deg)
4
5
n-C8H17
n-C8H17
Me
Cy
3.094
3.208
3.060
2.861
2.841
175.8
177.9
177.6
172.8
172.2
172.8
175.9
177.4
175.9
173.2
172.2
174.0
4,4′′-Bis(trichlorotin)-1,1′:4′,1′′-terphenyl (10). SnCl4 (2 mL,
17 mmol) was slowly added to a solution of 4,4′′-bis(tricyclohexy-
ltin)-1,1′:4′,1′′-terphenyl (6.5 g, 6.7 mmol) in toluene (200 mL).
After stirring at room temperature for 3 h, the mixture was warmed
to 70 °C under stirring for 24 h, and the solvent was evaporated
under reduced pressure. The solid was extracted with petroleum
ether (4 × 30 mL) to remove the tricyclohexyltin chloride. The
solvent was evaporated to give 10 (3.95 g) as a white solid. Mp:
6
n-C16H33 Me
n-C8H17 Cl
n-C16H33 Cl
n-C8H17
13
14
20
propynyl 2.964
of tert-butyllithium (34.2 mL, 1.5 M in pentane, 4 equiv) the white
suspension turned slightly orange after 4 h under stirring. The
mixture was warmed to room temperature for 2 h, and the
suspension turned yellow. It was cooled to -78 °C again, before
adding a solution of tricyclohexyltin chloride (13.0 g, 32.2 mmol)
in THF (100 mL). After 30 min, the reaction was allowed to warm
to room temperature. After stirring for 72 h, the mixture was
hydrolyzed with a saturated solution of NH4Cl and extracted. The
solvents were removed in vacuo. The resulting product was
recrystallized from 2-methylbutan-2-ol to give 1 (5.71 g) in a 50%
yield. Mp: 227 °C. 1H NMR: δ 1.1-1.2 (m, 66H), 7.5-7.65 (m,
8H). 13C NMR: δ 27.2 [334], 27.4, 29.6 [56], 32.6 [16], 126.6
[36], 137.8 [26], 140, 140.8. 119Sn NMR: δ -101.7. Anal. Calcd
for C48H74Sn2: C, 64.88; H, 8.39; Sn, 26.72. Found: C, 65.13; H,
8.31; Sn, 26.84.
1
200 °C. Yield: 87%. H NMR: δ 7.74 (s, 4H), 7.75-7.90 (m,
8H). 13C NMR: δ 128.2, 128.9, 134.7, 135.3, 139.7, 145.4. 119Sn
NMR: δ -58.4. Anal. Calcd for C18H12Cl6Sn2: C, 31.87; H, 1.78;
Cl, 31.35; Sn, 35.00. Found: C, 31.66; H, 2.02; Cl, 31.09; Sn, 31.30.
4,4′′-Bis(triprop-1-ynyltin)-1,1′:4′,1′′-terphenyl (17). 17 was
prepared as 16. Mp: 250 °C (dec). Yield: 60%. 1H NMR: δ 1.96
(s, 18H, [15]), 7.6-7.8 (m, 12H). 13C NMR: δ 5.4 [16], 76.1 [931],
108.6 [193], 127.6 [80], 127.8 [72], 134.1, 136.2 [58], 140.2, 142.5
[15]. 119Sn NMR: δ -285.2 [931, 193, 80]. Anal. Calcd for C24H30-
Sn2: C, 61.77; H, 4.32; Sn, 33.92. Found: C, 51.64; H, 4.56; Sn,
32.56.
4,4′-Bis(tricyclohexyltinmethyl)biphenyl (3). A solution of 4,4′-
bis(chloromethyl)biphenyl (7.77 g, 30.9 mmol) and chlorotricy-
clohexyltin (25 g, 61.9 mmol) in 100 mL of THF was added
dropwise to a suspension of magnesium (5 g, 206 mmol) in 50 mL
of THF. The mixture was then refluxed for 2 h. After hydrolysis,
extraction with pentane (200 mL), and drying, the solvents were
evaporated. The resulting product was recrystallized from 2-me-
thylbutan-2-ol to give 3 (22.6. g) as a white solid. Mp: 158 °C.
4,4′-Bis(trichlorotin)biphenyl (9). SnCl4 (2.5 mL, 21.3 mmol)
was slowly added to a solution of 4,4′-bis(tricyclohexyltin)biphenyl
(7 g, 7.9 mmol) in toluene (100 mL). After stirring at room
temperature for 3 h, the mixture was warmed to 70 °C for 12 h.
Then the solvent was evaporated under reduced pressure. Aceto-
nitrile (100 mL) was added. The solution was extracted with pentane
(5 × 50 mL) to remove the tricyclohexyltin chloride. To displace
acetonitrile, a washing with THF (2 × 300 mL) was performed.
1
Yield: 80%. H NMR: δ 1-2 (m, 66H), 2.34 (s, 4H [52]), 7.08
(d, 4H [8]), 7.40 (d, 4H [8]). 13C NMR: δ 15.6 [201], 27.2 [320],
27.4, 29.5 [55], 32.4 [16], 126.6, 127.9 [18], 136.1 [12], 142.7 [32].
1
Mp: 85 °C. Yield: 5 g (85%). H NMR: δ 7.18 (s, 8H) [125,
108, 44, 31] with coordinated acetonitrile (or 7.70-7.9 (m, 8H)
with coordinated THF). 13C NMR: δ 129.1 [128, 4], 134.9 [80],
136.5, 144.3. 119Sn NMR: δ -68.1 (with coordinated acetonitrile),
-163.3 (with coordinated THF). Anal. Calcd for C12H8Cl6Sn2‚
(33) Wang, Z.; Heising, J. M.; Clearfield, A. J. Am. Chem. Soc. 2003,
125, 10375.
(34) Shea, K. J.; Loy, D. A.; Webster, O. J. Am. Chem. Soc. 1992, 114,
6700.

R,ω-Bis(trialkynyltin) Compounds
Organometallics, Vol. 26, No. 16, 2007 3915
119Sn NMR: -74.4. Anal. Calcd for C50H78Sn2: C, 65.52; H, 8.58;
Sn, 25.90. Found: C, 65.22; H, 8.87; Sn, 24.74.
4,4′-Bis(4-(triprop-1-ynyltin)butyl)biphenyl (19). 19 was pre-
pared as 16. Mp: 107 °C. Yield: 62%. H NMR: δ 1.25 (t, 4H
1
[76]), 1.68 (m, 8H), 1.83 (s, 18H [14]), 2.60 (t, 4H), 7.17 (d, 4H),
4,4′-Bis(trichlorotinmethyl)biphenyl (11). SnCl4 (6 mL, 51,1
mmol) was slowly added to a solution of 3 (17.59 g, 19.2 mmol)
in 60 mL of toluene at 0 °C. After stirring overnight, toluene and
excess SnCl4 were evaporated. The residue was taken up in
acetonitrile (250 mL) and extracted with pentane (5 × 60 mL).
Evaporation of acetonitrile gave a green oil, which was washed
with THF (2 × 300 mL). 11 (9.68 g) was obtained as a solid after
7.41 (d, 4H). 13C NMR: δ 5.3 [15], 15.0 [633], 25.3 [30], 34.7
[84], 35.0, 76.8 [802], 107.9 [168], 126.9, 128.9, 138.6, 141.3. 119
-
Sn NMR: δ -252, 0 [802, 167]. Anal. Calcd for C38H42Sn2: C,
60.00; H, 5.75; Sn, 32.25. Found: C, 60.79; H, 5.88; Sn, 32.08.
2,5-Dibromo-1,4-dialkoxybenzenes. To a solution of 1,4-
dialkoxybenzene36 (67.0 mmol) in dichloromethane (500 mL) was
added dropwise bromine (26.8 g, 168 mmol) in dichloromethane
(20 mL). The reaction mixture was stirred at room temperature for
72 h. An aqueous solution of potassium hydroxide (300 mL) was
then added, extracted with dichloromethane, and dried over
anhydrous MgSO4. The solvent was removed in vacuo. Recrystal-
lization from ethanol gave pure 2,5-dibromo-1,4-dialkoxybenzenes.
1
evaporation of THF. Yield: 80%. Mp: 125 °C dec. H NMR: δ
3.72 (s, 4H [107]), 7.36 (d, 4H [8]), 7.60 (d, 4H [8]). 119Sn NMR:
δ -63.5.
4,4′-Bis(triprop-1-ynyltinmethyl)biphenyl (18). 18 was pre-
1
pared as 16. Mp: 178 °C. Yield: 70%. H NMR: δ 1.88 (s, 18H
[15]), 2.71 (s, 4H [96]), 7.22 (d, 4H), 7.48 (d, 4H). 13C NMR: δ
5.3 [16], 23.0 [575], 76.2 [851], 108.5 [174], 126.9 [21, 7], 128.5
[39], 136.7 [60], 137.8 [26, 11]. 119Sn NMR: δ -262.5 [852, 173,
54]. Anal. Calcd for C32H30Sn2: C, 58.95; H, 4.64; Sn, 36.41.
Found: C, 59.12; H, 4.59; Sn, 36.31.
1
2,5-Dibromo-1,4-dioctyloxy benzene: mp 73 °C, 88% yield. H
NMR: δ 0.90 (t, 6H), 1.2-1.6 (m, 20H), 1.8 (q, 4H), 3.94 (t, 4H),
7.08 (s, 4H). 13C NMR: δ 14.2, 22.8, 26.1, 29.3, 29.40, 29.45,
31.9, 70.4, 111.3, 118.5, 150.2. 2,5-Dibromo-1,4-di(hexadecyloxy)-
1
benzene: mp 89 °C, 76% yield. H NMR: δ 0.88 (t, 6H), 1.15-
4,4′-Bis(4-but-3-enyl)biphenyl. A solution of allyl chloride
(19.13 g, 250 mmol) in 120 mL of ether was slowly added to a
suspension of magnesium (6 g, 250 mmol) in 20 mL of ether. After
refluxing for 2 h, the Grignard reagent solution was transferred
via a cannula to a solution of 1-bromo-4-(bromomethyl)benzene
(7.49 g, 30 mmol) in THF (100 mL). After refluxing for 30 min,
the mixture was hydrolyzed with a saturated NH4Cl solution. After
extraction, washing with water, drying, and evaporation of the
solvents, 1-bromo-4-(but-3-enyl)benzene was purified by distilla-
tion. Bp: 130 °C/20 mmHg. To a 1 M solution of 4-(but-3-enyl)-
benzylmagnesium in THF (50 mL 50 mmol) at -80 °C was slowly
added TiCl4 (14.25 g, 75 mmol).35 After stirring for 30 min at 0
°C, the mixture was hydrolyzed with a NH4Cl-saturated solution.
After extraction, drying, and evaporation of the solvents 4,4′-bis-
(4-but-3-enyl)biphenyl (8.0 g) was purified by Kugelrohr distillation.
1.6 (m, 56H), 1.80 (q, 4H), 3.95 (t, 4H), 7.01 (s, 4H). 13C NMR:
δ 14.3, 22.9, 26.1, 29.3, 29.51, 29.58, 29.77, 29.8, 29.87, 29.92,
32.1, 70.5, 113.3, 118.6, 150.2.
2,5-Bis(tricyclohexyltin)-1,4-dioctyloxybenzene (5). A solution
of 2,5-dibromo-1,4-dioctyloxybenzene (10 g, 20.3 mmol) in diethyl
ether (400 mL) was cooled to -78 °C. With the addition of tert-
butyllithium (54.18 mL, 1.5 M in pentane, 4 equiv) a white
suspension was obtained, which turned to greenish-yellow after 4
h under stirring.37 The mixture was warmed to room temperature
for 2 h. It was cooled again to -78 °C, and a solution of
tricyclohexyltin chloride (20.6 g, 51 mmol) in THF (120 mL) was
added. After 30 min, the reaction was allowed to warm to room
temperature. After stirring for 72 h, the mixture was hydrolyzed
with a saturated solution of NH4Cl and extracted. The organic layer
was dried over anhydrous MgSO4. The solvents were removed in
vacuo. The resulting solid was recrystallized from chloroform to
1
Bp: 140 °C/0.001 mmHg. Yield: 61%. H NMR: δ 2.40-2.60
(m, 4H), 2.87 (t, 4H), 5.05-5.30 (m, 4H), 5.90-6.10 (m, 2H), 7.36
(d, 4H), 7.63 (d, 4H). 13C NMR: δ 35.1, 35.6, 115.1, 127.0, 128.9,
138.2, 138.8, 140.8.
1
give 5 (6.85 g). Mp: 176.4 °C. Yield: 50%. H NMR: δ 0.91 (t,
6H), 1.1-2.1 (m, 90H), 3.89 (t, 4H), 6.84 (s, 2H, [19, 41]). 13C
NMR: δ 14.3, 22.9, 26.5, 27.5, 27.8 [350], 29.7 [58], 32.1, 32.5
[15], 68.2, 118.4 [23], 129.6 [334], 157.4. 119Sn NMR: δ -92.3.
Anal. Calcd for C58H102O2Sn2: C, 65.17; H, 9.62; O, 2.99; Sn,
22.21. Found: C, 64.46; H, 9.58; O, 2.99; Sn, 20.31.
4,4′-Bis(4-(tricyclohexyltin)butyl)biphenyl (8). A solution of
4,4′-bis(4-but-3-enyl)biphenyl (6 g, 22.9 mmol), tricyclohexyltin
hydride (15.2 g, 41,2 mmol), and AIBN (0.6 g, 3.6 mmol) was
heated at 110 °C for 4 days and then at 130 °C for 3 more days.
During that period, small portions of AIBN (100 mg) were added
about every 6 h. The crude mixture was purified by chromatography
on silica gel (eluent: chloroform) to give 8 (12.36 g) as a white
solid. Yield: 60%. Mp: 143 °C. 1H NMR: δ 0.80-0.92 (m, 4H),
1.27-1.87 (m, 74H), 2.68 (t, 4H), 7.27 (d, 4H), 7.57 (d, 4H). 13C
NMR: δ 6.7, 26.2[321]) 27.1 [18], 27.4, 29.5, [52], 32.6 [16], 35.2,
36.8 [51], 126.9, 128.9, 138.7, 141.8. 119Sn NMR: δ -64.5. Anal.
Calcd for C56H90Sn2: C, 67.21; H, 9.06; Sn, 23.72. Found: C,
66.45; H, 8.93; Sn, 23.076.
2,5-Bis(trimethyltin)-1,4-dioctyloxybenzene (4). A solution of
2,5-dibromo-1,4-dioctyloxybenzene (13.5 g, 27.4 mmol) in diethyl
ether (600 mL) was cooled to -78 °C. With the addition of tert-
butyllithium (73.2 mL, 1.5 M in pentane, 4 equiv) a white
suspension was obtained, which turned to greenish-yellow after 4
h under stirring. The mixture was warmed to room temperature
for 2 h. It was cooled again to -78 °C, and a solution of
tricyclohexyltin chloride (13.71 g, 68.8 mmol) in THF (120 mL)
was added. After 30 min, the reaction was allowed to warm to
room temperature. After stirring for 72 h, the mixture was
hydrolyzed with a saturated solution of NH4Cl and extracted. The
organic layer was dried over anhydrous MgSO4. The solvents were
removed in vacuo. The resulting solid was recrystallized from
4,4′-Bis(4-(trichlorotin)butyl)biphenyl (12). SnCl4 (1.79 mL,
15,3 mmol) was added to a solution of 8 (4.2 g, 5.9 mmol) in 150
mL of toluene. After stirring for 72 h at room temperature, the
solvent and the excess SnCl4 were evaporated. The residue was
taken up in acetonitrile (150 mL) and the solution extracted with
pentane (7 × 100 mL). After evaporation of acetonitrile, the solid
was solubilized in THF (100 mL). Evaporation of the solvent gave
1
ethanol to give 4 (13.0 g). Mp: 93 °C. Yield: 72%. H NMR: δ
0.29 (s, 18H, [56]), 0.92 (t, 6H), 1.3-1.55 (m, 20H), 1.77 (q, 4H),
3.93 (t, 4H), 6,87 (s, 2H, [22, 52]), 13C NMR: δ -8.7 [359], 14.3,
22.9, 26.4, 29.5, 29.6, 29.9, 32.0, 68.4, 117.3 [30], 132.0 [453],
157.8 [22, 52]. 119Sn NMR: δ -32.2. Anal. Calcd for C28H54O2-
Sn2: C, 50.94; H, 8.24; O, 4.85; Sn, 35.96. Found: C, 50.85; H,
8.10; O, 4.57; Sn, 32.60.
1
12 (4.1 g) as a white solid. Mp: 107 °C. Yield: 97%. H NMR:
δ 1.74-1.79 (m, 4H), 1.89-1.94 (m, 4H), 2.31 (t, 4H [79]), 2.65
(t, 4H), 7.16 (d, 4H), 7.44 (d, 4H). 13C NMR: δ 24.6 [58], 32.8
[657], 34.1 [106], 34.8, 127.3, 129.0, 139.0, 140.1. 119Sn NMR: δ
7.8. Anal. Calcd for C20H24Cl6Sn2: C, 33.62; H, 3.39; Cl, 29.77;
Sn, 33.23. Found: C, 33.77; H, 3.48; Cl, 28.44; Sn, 32.23.
2,5-Bis(trichlorotin)-1,4-dioctyloxybenzene (13). SnCl4 (8.55
mL, 72.8 mmol) was slowly added to a solution of 4 (6 g, 9.1
(36) Tamura, H.; Watanabe, T.; Imanishi, K.; Sawada, M. Synth. Met.
1999, 107, 19.
(37) Lightowler, S.; Hird, M. Chem. Mater. 2004, 16, 3963.
(35) Inoue, A.; Kitagawa, K.; Shinokubo, H.; Oshima, K. Tetrahedron
2000, 56, 9601.

3916 Organometallics, Vol. 26, No. 16, 2007
Elhamzaoui et al.
mmol). The mixture was warmed to 120 °C under stirring for 4.5
h. The excess SnCl4 and the secondary products were then
evaporated under reduced pressure at 120 °C to give 13 (6.7 g).
Mp: 133 °C. Yield: 94%. 1H NMR: δ 0.91 (t, 6H), 1.25-1.6 (m,
20H), 1.88 (q, 4H), 4.15 (t, 4H), 7.21 (s, 2H, [145, 72]). 13C
NMR: δ 14.3, 22.8, 25.9, 28.9, 29.32, 29.36, 31.9, 71.1, 116.9,
132.6 [22, 133], 156.0 [157]. 119Sn NMR: δ -83.5. Anal. Calcd
for C22H36O2Cl6Sn2: C, 33.76; H, 4.64; O, 4.09; Cl, 27.18; Sn,
30.34. Found: C, 34.22; H, 4.55; O, 4.40; Cl, 26.71; Sn, 27.06.
2,5-Bis(triprop-1-ynyltin)-1,4-dioctyloxybenzene (20). To a
solution of propyne (87.3 mmol) in toluene (76 mL) at -78 °C
was slowly added a solution of n-butyllithium (31.56 mL, 48 mmol)
in hexane (2.0 M). After 2 h stirring at room temperature, a solution
of 2,5-bis(trichlorotin)-1,4-dioctyloxybenzene (6.5 g, 8.3 mmol) in
toluene (100 mL) was added at -78 °C. The suspension was stirred
at room temperature for 12 h and then filtered on dry MgSO4. After
evaporation of the solvents, 20 (5.0 g) was recovered as a white
solid. Mp: 165 °C. Yield: 75%. 1H NMR: δ 0.88 (t, 6H), 1.20-
1.60 (m, 20H), 1.80 (q, 4H), 1.92 (s, 18H, [15]), 4.00 (t, 4H), 7.10
(s, 2H, [40, 94]). 13C NMR: δ 5.3 [16], 14.2, 22.8, 26.1, 29.3,
29.4, 29.6, 32.0, 69.4, 71.1 [956], 107.1 [196], 118.2 [51], 128.0
[13, 885], 157.2 [98]. 119Sn NMR: δ -296.5 [957, 197, 37]. Anal.
Calcd for C40H54O2Sn2: C, 59.73; H, 6.97; O, 3.58; Sn, 29.52.
Found: C, 59.87; H, 6.87; O, 3.75; Sn, 29.93.
2,5-Bis(trimethyltin)-1,4-di(n-hexadecyloxy)benzene (6). 6 was
prepared in the same way as 4. Mp: 88 °C. Yield: 50%. 1H
NMR: δ 0.29 (s, 18H, [55]), 0.89 (t, 6H), 1.15-1.6 (m, 56H),
1.75 (q, 4H), 3.91 (t,4H), 6,85 (s, 2H, [22, 53]). 13C NMR: δ -8.7
[359], 14.3, 22.9, 26.3, 29.5, 29.6, 29.8, 29.9, 32.1, 68.4, 117.3 [7,
30], 131.9, 157.7. 119Sn NMR: δ -32.2. Anal. Calcd for C44H86O2-
Sn2: C, 59.74; H, 9.81; O, 3.61; Sn, 26.83. Found: C, 60.68; H,
9.95; O, 3.82; Sn, 24.60.
2,5-Bis(trichlorotin)-1,4-di(n-hexadecyloxy)benzene (14). 14
1
was prepared as 13. Mp: 111 °C. Yield: 91%. H NMR: δ 0.88
(t, 6H), 1.15-1.6 (m, 56H), 1.83 (q, 4H), 4.13 (t, 4H), 7.19 (s, 2H,
[72, 145]). 13C NMR: δ 14.3, 22.9, 25.9, 28.9, 29.4, 29.5, 29.6,
29.7, 29.8, 29.9, 32.1, 71.1, 116.9, 132.6, 156.0. 119Sn NMR: δ
-83.3. Anal. Calcd for C38H68Cl6O2Sn2: C, 45.32; H, 6.81; O, 3.18;
Cl, 21.12; Sn, 23.97. Found: C, 47.00; H, 6.99; O, 3.85; Cl, 19.88;
Sn, 21.31.
2,5-Bis(triprop-1-ynyltin)-1,4-di(n-hexadecyloxy)benzene (21).
21 was prepared in the same way as 20. Mp: 90 °C. Yield: 78%.
1H NMR: δ 0.88 (t, 6H), 1.15-1.60 (m, 56H), 1.83 (q, 4H), 1.93
(s, 18H, [15]), 4.01 (t, 4H), 7,11 (s, 2H, [41, 94]). 13C NMR: δ
5.4 [16], 14.3, 22.8, 26.2, 29.4, 29.5, 29.81, 29.85, 29.9, 32.1, 69.5,
71.1 [955], 107.2 [196], 118.3 [52], 128.0, 157.3. 119Sn NMR: δ
-296.6 [37]. Anal. Calcd for C56H86O2Sn2: C, 65.39; H, 8.43; O,
3.11; Sn, 23.08. Found: C, 65.98; H, 8.58; O, 3.32; Sn, 21.10.
4,4′′-Bis(trimethyltin)-2′,5′-dioctyloxy-1,1′:4′,1′′-terphenyl (7).
A 30 mL portion of a solution of 20 mL of 4,4′′-dibromo-2′,5′-
dioctyloxy-1,1′:4′,1′′-terphenyl37 (10.08 g, 15.6 mmol) in dry THF
(300 mL) was slowly added to magnesium (1.6 g, 60 mmol) in
THF (40 mL). The mixture was heated to initiate the reaction. The
rest of the solution was slowly added under reflux, and the mixture
was refluxed for 2 h. After cooling to 0 °C, a solution of trimethyltin
chloride (48.60 g, 120 mmol) in dry THF (200 mL) was slowly
added. The mixture was stirred at room temperature overnight and
then hydrolyzed with a saturated solution of NH4Cl and extracted
with pentane. The organic phase washed with water and dried with
MgSO4, and the solvents were evaporated. Recrystallization from
toluene gave 7 (11.0 g) as a white solid. Mp: 104 °C. Yield: 87%.
1H NMR: δ 0.43 (s, 18H, [55]), 0.98 (t, 6H), 1.3-1.6 (m, 20H),
1.79 (q, 4H), 4.01 (t, 4H), 7.09 (s,2H), 7.62-7.75 (m, 8H). 13C
NMR: δ -9.3 [350], 14.3, 22.8, 26.3, 29.4, 29.5, 32.0, 69.7, 116.4,
129.3 [46], 130.9, 135.6 [11], 138.5, 140.8 [465], 150.4. 119Sn

R,ω-Bis(trialkynyltin) Compounds
Organometallics, Vol. 26, No. 16, 2007 3917
NMR: δ -27.0 [349]. Anal. Calcd for C40H62O2Sn2: C, 59.14; H,
7.69; O, 3.94; Sn, 29.22. Found: C, 59.12; H, 7.72; O, 4.12; Sn,
28.21.
with mineral oil (Aldrich), mounted onto glass fibers, and trans-
ferred directly to the 150 K N2 stream of a Nonius Kappa CCD
diffractometer, or were mounted onto a 1.0 mm glass capillary at
room temperature. Structures were solved by direct methods
(SHELXS97)38 and refined by full-matrix least-squares against F2
using SHELXL97.39 All non-H atoms were refined anisotropically
with the exception of disordered atoms. H atoms were fixed in
calculated positions at parent C atoms. The locations of the largest
peaks in the final difference Fourier map calculation as well as the
magnitude of the residual electron densities in each case were of
no chemical significance.
4,4′′-Bis(trichlorotin)-2′,5′-dioctyloxy-1,1′:4′,1′′-terphenyl (15).
1
15 was prepared as 13. Mp: 125 °C. Yield: 90%. H NMR: δ
0.89 (t, 6H), 1.15-1.65 (m, 20H), 1.72 (q, 4H), 3.96 (t, 4H), 6.98
(s, 2H), 7.72 (d, 4H), 7.85 (m, 4H). 13C NMR: δ 14.3, 22.8, 26.2,
29.39, 29.41, 31.9, 69.8, 115.9, 130.0 [12], 131.5 [126], 133.7 [81],
134.7, 143.5, 150.4. 119Sn NMR: δ -59.3. Anal. Calcd for
C36H44O2Sn2: C, 43.69; H, 4.74; O, 3.42; Cl, 22.75; Sn, 25.39.
Found: C, 44.67; H, 4.94; O, 3.88; Sn, 24.86.
4,4′′-Bis(triprop-1-ynyltin)-2′,5′-dioctyloxy-1,1′:4′,1′′-terphe-
nyl (22). 22 was prepared as 20. Mp: 180 °C (dec). Yield: 65%.
1H NMR: δ 0.89 (t, 6H), 1.15-1.45 (m, 20H), 1.71 (q, 4H), 1.97
(s, 18, [15]), 3.92 (t, 4H), 6.97 (s, 2H), 7.69 (m, 8H). 13C NMR:
δ 5.4 [15], 14.3, 22.8, 26.2, 29.40, 29.48, 31.9, 69.7, 76.3 [924],
108.4 [191], 116.3, 130.0 [78], 130.7, 133.4 [81], 135.3 [58], 140.4,
150.4. 119Sn NMR: δ -285.7. Anal. Calcd for C56H86O2Sn2: C,
65.30; H, 6.53; O, 3.35; Sn, 24.82. Found: C, 65.84; H, 6.52; O,
3.43; Sn, 23.72.
Acknowledgment. The authors thank the Aquitaine Region,
the Centre National de la Recherche Scientifique (Material
Program Grant), and the European Community (FAME Network
of Excellence) for partial financial support of this work. The
authors are grateful to Sipcam Phyteurop for a generous gift of
chemicals.
Supporting Information Available: Tables with bond lengths,
bond angles, atomic coordinates, and anisotropic displacement
parameters for the structures of 2-7, 12-14, and 20. This
information is available free of charge via the Internet at
http://pubs.acs.org.
X-ray Crystallography. Crystal data collection and processing
parameters are given in Table 2. Suitable crystals were covered
(38) Sheldrick, G. M. Acta Crystallogr. Sect. A 1990, 46, 467.
(39) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure
Refinement; Universita¨t von Go¨ttingen: Go¨ttingen, Germany, 1997.
OM070078P