αω-bis(trichlorostannyl)alkanes: Unravelling the hydrolysis pathway to organotin-oxo oligomers

Article abstract of DOI:10.1021/om010202j

New αω-bis(trichlorostannyl)alkanes, Cl₃Sn(CH₂)_nSnCl₃ [n = 3-5, 8], have been synthesized via tin-phenyl bond cleavage reactions on α,ω-bis(triphenylstannyl)alkanes, Ph₃Sn(CH₂)_nS

Full text of DOI:10.1021/om010202j

2820
Organometallics 2001, 20, 2820-2826
r,ω-Bis(tr ich lor osta n n yl)a lk a n es: Un r a vellin g th e
Hyd r olysis P a th w a y to Or ga n otin -oxo Oligom er s
Bernhard Zobel, Andrew Duthie, and Dainis Dakternieks*
Centre for Chiral and Molecular Technologies, Deakin University,
Geelong, Victoria 3217, Australia
Edward R. T. Tiekink
Department of Chemistry, The University of Adelaide, South Australia 5005, Australia
Received March 14, 2001
New R,ω-bis(trichlorostannyl)alkanes, Cl3Sn(CH2)nSnCl3 [n ) 3-5, 8], have been synthe-
sized via tin-phenyl bond cleavage reactions on R,ω-bis(triphenylstannyl)alkanes, Ph3Sn-
(CH2)nSnPh3 [n ) 3-5, 8], using either SnCl4 or concentrated hydrochloric acid. Some key
missing links, (H2O)Cl3Sn(CH2)3SnCl3(H2O) (1a ) and (H2O)2Cl3Sn(CH2)3SnCl3(H2O)2 (6), in
the hydrolysis pathway of organotin trichlorides were identified. Crystal structures of the
nonassociated di-tin compounds (H2O)Cl3Sn(CH2)3SnCl3(H2O) (1a ) and (H2O)2Cl3Sn(CH2)3-
SnCl3(H2O)2 (6, isolated as the 18-crown-6 cocrystal acetonitrile solvate) as well as the
polymeric hydrolysis product [H2O(OH)Cl2Sn(CH2)3SnCl2(OH)H2O‚2H2O]n (7‚2H2O) are
reported.
In tr od u ction
The use of polymethylene bridged di-tin precursors,
RX2Sn(CH2)nSnX2R, makes it possible to introduce a
third dimension by linking two ladder units to give a
double ladder type structure4,11 B. This theme has been
repeated with the formation of triple15 and quadruple16
ladders from appropriate tri- and tetra-tin precursors.
Oligomers based on organotin-oxo structures are of
current interest because of their extensive potential as
new materials1,2 and their use as mild Lewis acid
catalysts3-5 for organic reactions. Control over the
degree of oligomerization still represents some synthetic
challenges. Oligomers have been most usually synthe-
sized by hydrolysis reaction of diorganotin and mono-
organotin precursors, R2SnX2 and RSnX3, respectively.
For example, the partial hydrolysis of diorganotin
dihalides usually affords dimeric tetraorganodistann-
oxanes [R2(X)SnOSn(X)R2]2, which have the two-dimen-
sional planar Sn4X2O2 ladder structure6-10 A (Chart 1).
More recently these organotin-oxo oligomers were ac-
cessed by reaction of appropriate precursors with an
oxygen transfer source such as (tBu2SnO)3.11-14
On the other hand, the hydrolysis reactions of RSnX3
precursors are more complicated and only relatively few
oligomers have been characterized.17-22 The most in-
n
teresting of these is [(RSn)12O14(OH)6]X2 (R ) iPr, Bu;
X ) Cl, OH]22-25 because of their potential for further
oligomerization to give new materials. The current trend
is to attempt oligomerization/polymerization by use of
anions, X, which have functionality, e.g., meth-
acylate.26-27 Our strategy to form new organotin-oxo
clusters is to use linked di-tin precursors R,ω-bis-
(trichlorostannyl)alkanes, Cl3Sn(CH2)nSnCl3, in place of
RSnCl3 as starting materials for the synthesis of tin-12
(1) Ribot, F.; Sanchez, C. Comments Inorg. Chem. 1999, 20 (4-6),
327.
(2) Ribot, F.; Eychenne-Baron, C.; Sanchez, C. Phosphorus Sulfur,
Silicon 1999, 150-151, 41.
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Chem. 1998, 558, 19.
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T.; Biesemans, M.; Willem, R. J . Organomet. Chem. 1998, 552, 177.
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ganometallics 1994, 13, 4121.
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T. Inorg. Chem. 1997, 36, 2023.
(13) Zobel, B.; Schu¨rmann, M.; J urkschat, K.; Dakternieks, D.;
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Chem. Commun. 1199, 1291.
(16) Schulte, M. Ph.D. Thesis, University of Dortmund, 2000.
(17) J ohnson, S. E.; Knobler, C. B. Organometallics 1994, 13, 4928.
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1976, 32, 923.
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M.; Day, R. O. J . Am. Chem. Soc. 1988, 110, 1174.
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Organomet. Chem. 1994, 476, 33.
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Chem. 1995, 34, 6371.
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1998, 567, 137.
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10.1021/om010202j CCC: $20.00 © 2001 American Chemical Society
Publication on Web 05/23/2001

R,ω-Bis(trichlorostannyl)alkanes
Organometallics, Vol. 20, No. 13, 2001 2821
Ch a r t 1
compounds. This strategy could lead to further linkage
of tin-12 units, D, or afford tin-12 with organic “handles”
C.
Resu lts a n d Discu ssion
Syn th esis of th e P olym eth ylen e Sp a cer -Br id ged
Di-tin Com p ou n d s (1-5). The reaction of R,ω-bis-
(triphenylstannyl)alkane Ph3Sn(CH2)nSnPh3
3-5, 8) with either SnCl4 or concentrated hydrochloric
acid afforded the related R,ω-bis(trichlorostannyl)-
alkanes Cl3Sn(CH2)nSnCl3 (1-4) in good to moderate
yields (eqs 1 and 2). The reaction according to eq 1 was
also used to prepare the known Cl3SnCH2SnCl3 for
purposes of comparison.
Thus far, Cl3SnCH2SnCl3 is the only member of the
series of R,ω-bis(trichlorostannyl)alkanes that has been
reported.28 It was synthesized via the reaction of
(vinyl)3SnCH2Sn(vinyl)3 with excess SnCl4. Since tin-
phenyl bonds are even more readily cleaved than tin-
vinyl bonds,29,30 we decided to use R,ω-bis(triphenyl-
stannyl)alkanes Ph3Sn(CH2)nSnPh3 as precursors for
the synthesis of R,ω-bis(trichlorostannyl)alkanes Cl3Sn-
(CH2)nSnCl3. We now report on the synthesis of various
polymethylene-bridged di-tin hexahalides and crystal
structures of the diaquo adduct (H2O)Cl3Sn(CH2)3SnCl3-
(H2O) (1a ), the tetraaquo adduct (H2O)2Cl3Sn(CH2)3-
SnCl3(H2O)2 (6), and the partially hydrolyzed polymeric
material [H2O(OH)Cl2Sn(CH2)3SnCl2(OH)H2O‚2H2O]n
(7‚2H2O).
31,32
(n )
Ph3Sn(CH2)nSnPh3 + 6 SnCl4 120-130 °C, 3 h8
Cl3Sn(CH2)nSnCl3 + 6 PhSnCl3
(1)
1, n ) 3; 2, n ) 4; 3, n ) 5;
4, n ) 8
Ph3Sn(CH2)nSnPh3 + HCl(concentrated) 60 °C, 3 h8
(28) Karol, T. J .; Hutchinson, J . P.; Hyde, J . R.; Kuivila, H. G.;
Zubieta, J . A. Organometallics 1983, 2, 106.
(29) Seyferth, D. J . Am. Chem. Soc. 1957, 79, 2133.
(30) Davies, A. G.; Smith, P. J . In Comprehensive Organometallic
Chemistry; Wilkinson, G., Ed.; Pergamon Press: Oxford, 1982; Vol. 2,
p 537.
Cl3Sn(CH2)nSnCl3 + 6 C6H6
1, n ) 3; 2, n ) 4;
The basic concept of Sn-Ph cleavage with tin tetra-
halogenides was successfully extended to the synthesis
(2)

2822 Organometallics, Vol. 20, No. 13, 2001
Zobel et al.
Ta ble 1. Selected In ter a tom ic (Å, d eg) P a r a m eter s
for (H2O)Cl3Sn (CH2)3Sn Cl3(H2O) (1a )a
Sn-Cl(1)
Sn-Cl(3)
Sn-C(1)
2.405(2)
2.337(1)
2.122(3)
Sn-Cl(2)
Sn-O(1)
C(1)-C(2)
2.321(1)
2.353(2)
1.509(3)
Cl(1)-Sn-Cl(2)
Cl(1)-Sn-O(1)
Cl(2)-Sn-Cl(3)
Cl(2)-Sn-C(1)
Cl(3)-Sn-C(1)
Sn-C(1)-C(2)
93.30(5)
172.20(5)
109.62(4)
122.46(8)
122.82(8)
116.4(2)
Cl(1)-Sn-Cl(3)
Cl(1)-Sn-C(1)
Cl(2)-Sn-O(1)
Cl(3)-Sn-O(1)
O(1)-Sn-C(1)
C(1)-C(2)-C(1)i
94.00(3)
104.30(8)
81.24(7)
82.70(6)
83.39(9)
108.0(3)
a
Symmetry operation i: -x, y, 0.5 - z.
Ta ble 2. Tem p er a tu r e Dep en d en ce of th e 119Sn
Ch em ica l Sh ift a n d Cou p lin g of 1a a n d 5
F igu r e 1. Molecular structure and atomic numbering
scheme for (H2O)Cl3Sn(CH2)3SnCl3(H2O) (1a ).
compound
solvent
CDCl3
temp
δ
119Sn
4J (117Sn-119Sn)
Sch em e 1. P ossible Hyd r olysis P a th w a y for 1
1a
20
-25
-50
80
-0.9
-4.0
-5.4
595
735
898
toluene-d8
0.26
n.o.
20
0
-20
-40
25
-25
-45
-0.54
-1.28
-2.21
-3.53
-168.88
-166.09
-164.59
886
1020
1190
1387
497
590
719
5
CDCl3
plane in the direction of the Cl(1) atom. The axial Sn-
Cl(1) distance is significantly longer than the remaining
two Sn-Cl distances (Table 1), and of the equatorially
bound chlorides, the Cl(3) atom forms the longer dis-
tance. While the difference between the axial and
equatorial Sn-Cl bond distances is electronic in origin,
an examination of the crystal structure is required to
rationalize the disparity in the Sn-Cl(2) and Sn-Cl(3)
bonds. In the lattice, the most significant intermolecular
contact occurs between centrosymmetrically related
pairs of O(1)-H(4) and Cl(3)i atoms so that H(4)‚‚‚Cl(3)i
is 2.51 Å, O(1)‚‚‚Cl(3)i is 3.329(3) Å, and O(1)-H(4)‚‚‚Cl(3)i
is 162°; symmetry operation i: 0.5 - x, 0.5 - y, -z.
These associations lead to the formation of kinked
chains. The Cl(2) atom does not participate in any
significant intermolecular interactions, and hence, the
slight elongation of the Sn-Cl(3) distance can be related
to the presence of the H‚‚‚Cl(3) contact. Translationally
related molecules associate via O(1)-H(5)‚‚‚Cl(1)ii inter-
actions: H(5)‚‚‚Cl(1)ii 2.58 Å, O(5)‚‚‚Cl(1)ii 3.290(2) Å,
and O(5)-H(5)‚‚‚Cl(1)ii 136°; symmetry operation ii: x,
1 + y, z. These contacts serve to link the aforementioned
chains into a two-dimensional array.
of Br3Sn(CH2)3SnBr3 5 via the reaction of Ph3Sn(CH2)3-
SnPh3 with an excess of SnBr4.
Compounds 1 and 2 are solids, whereas 3 and 4 are
highly viscous oils. The compounds are hygroscopic and
require storage in a moisture-free environment. All
bis(trichlorostannyl)alkanes are readily soluble in com-
mon organic solvents as well as in water.
Hyd r olysis Rea ction s. It is noteworthy that com-
pounds 1 and 2 crystallize as the diaquo adducts
Cl3(H2O)Sn(CH2)nSn(H2O)Cl3 (1a , n ) 3; 2a , n ) 4) and
appear to be the missing links in the early stages of the
hydrolysis pathway of organotin trihalides as illustrated
in Scheme 1. It is known that the neutral macrocycles,
such as crown ethers, can stabilize organotin halides
with respect to hydrolysis reactions.17 Reaction of 1
with 18-crown-6 in methanol and recrystallization from
acetonitrile afforded the tetraaquo adduct 6 (as the 18-
crown-6 cocrystal acetonitrile solvate). Compound 6
represents a stabilized example of the second hydrolysis
step (Scheme 1). Slow evaporation of a solution of 1 in
aqueous solution afforded [H2O(OH)Cl2Sn(CH2)3SnCl2-
(OH)H2O]n, 7, isolated as a dihydrate (7‚2H2O). The
solid-state structures of 1a , 2a ,33 6, and 7‚2H2O have
been determined by X-ray crystallography.
The 119Sn NMR shifts for analytically pure samples
of 1a and 2a in CDCl3 are δ 1.7 and 6.3, respectively,
indicating four coordinated tin centers and that the
coordinated water found in the crystal structure has
dissociated in solution. The chemical shift for 1a de-
The molecular structure of 1a is shown in Figure 1,
and selected interatomic parameters are collected in
Table 1. The molecule has crystallographic 2-fold sym-
metry and features trigonal bipyramidal tin centers
with the Cl(1) and O(1) atoms defining the axial
positions. The tin atom lies 0.2943(2) Å out of the CCl2
4
creases and the J (117Sn-119Sn) coupling increases as
the temperature is lowered (Table 2). The 119Sn NMR
shift of 1a in the solid state is at -42 ppm, but the
4
spectral quality is unable to distinguish J (117Sn-119Sn)
coupling. These observations are consistent with W-
interactions in which the more favorable bonding com-
ponent is favored as the temperature is decreased, the
most favorable conformer occurring in the solid state.
The 119Sn shift for 1a is not significantly concentration
dependent.
(31) Azuma, Y.; Newcomb, M. Organometallics 1984, 3, 9.
(32) Dakternieks, D.; J urkschat, K.; Schollmeyer, D.; Wu, H. J .
Organomet. Chem. 1995, 492, 145.
(33) Dakternieks, D.; Zobel, B.; Tiekink, E. R. T. Main Group Metal
Chem. 2000, 321, 23.

R,ω-Bis(trichlorostannyl)alkanes
Organometallics, Vol. 20, No. 13, 2001 2823
F igu r e 2. Molecular structure and atomic numbering
scheme for (H2O)2Cl3Sn(CH2)3SnCl3(H2O)2 in 6‚18-crown-
6‚CH3CN.
Ta ble 3. Selected In ter a tom ic (Å, d eg) P a r a m eter s
for (H2O)2Cl3Sn (CH2)3Sn Cl3(H2O)2
(6‚18-cr ow n -6‚CH3CN)
Sn(1)-Cl(1)
Sn(1)-Cl(2)
Sn(1)-Cl(3)
Sn(1)-O(1)
Sn(1)-O(2)
Sn(1)-C(1)
C(1)-C(2)
2.404(1)
2.370(1)
2.448(2)
2.405(3)
2.231(4)
2.137(5)
1.522(8)
Sn(2)-Cl(4)
Sn(2)-Cl(5)
Sn(2)-Cl(6)
Sn(2)-O(3)
Sn(2)-O(4)
Sn(2)-C(3)
C(2)-C(3)
2.372(2)
2.439(2)
2.419(1)
2.242(4)
2.287(3)
2.145(5)
1.525(8)
Cl(1)-Sn(1)-Cl(2)
Cl(1)-Sn(1)-Cl(3)
Cl(1)-Sn(1)-O(1)
Cl(1)-Sn(1)-O(2)
Cl(1)-Sn(1)-C(1)
Cl(2)-Sn(1)-Cl(3)
Cl(2)-Sn(1)-O(1)
Cl(2)-Sn(1)-O(2)
Cl(2)-Sn(1)-C(1)
Cl(3)-Sn(1)-O(1)
Cl(3)-Sn(1)-O(2)
Cl(3)-Sn(1)-C(1)
O(1)-Sn(1)-O(2)
O(1)-Sn(1)-C(1)
O(2)-Sn(1)-C(1)
Sn(1)-C(1)-C(2)
C(1)-C(2)-C(3)
93.79(5) Cl(4)-Sn(2)-Cl(5)
94.24(4) Cl(4)-Sn(2)-Cl(6)
174.15(9) Cl(4)-Sn(2)-O(3)
92.84(9) Cl(4)-Sn(2)-O(4)
91.63(5)
92.66(5)
82.3(1)
83.18(9)
162.3(1)
93.65(4)
171.2(1)
86.06(8)
98.3(1)
F igu r e 3. Molecular structure and atomic numbering
scheme for [H2O(OH)Cl2Sn(CH2)3SnCl2(OH)H2O]n in 7‚
2H2O.
102.4(1)
Cl(4)-Sn(2)-C(3)
90.10(5) Cl(5)-Sn(2)-Cl(6)
80.37(9) Cl(5)-Sn(2)-O(3)
Ta ble 4. Selected In ter a tom ic (Å, d eg) P a r a m eter s
for [H2O(OH)Cl2Sn (CH2)3Sn Cl2((OH)H2O.2H2O]n
(7‚2H2O)a
81.5(1)
161.3(1)
85.88(8) Cl(6)-Sn(2)-O(3)
Cl(5)-Sn(2)-O(4)
Cl(5)-Sn(2)-C(3)
Sn(1)-Cl(1)
Sn(1)-Cl(2)
Sn(1)-O(1)
Sn(1)-O(1)i
Sn(1)-O(2)
Sn(1)-C(1)
C(1)-C(2)
2.4248(6)
2.4258(8)
2.047(2)
2.164(2)
2.361(2)
2.140(3)
1.531(4)
Sn(2)-Cl(3)
Sn(2)-Cl(4)
Sn(2)-O(3)
Sn(2)-O(3)ii
Sn(2)-O(4)
Sn(2)-C(3)
C(2)-C(3)
2.4674(7)
2.4689(6)
2.051(2)
2.125(2)
2.220(2)
2.136(3)
1.514(4)
93.0(1)
169.4(1)
97.8(1)
86.3(1)
83.4(1)
88.4(2)
115.8(3)
110.5(3)
Cl(6)-Sn(2)-O(4)
Cl(6)-Sn(2)-C(3)
O(3)-Sn(2)-O(4)
O(3)-Sn(2)-C(3)
O(4)-Sn(2)-C(3)
Sn(2)-C(3)-C(2)
175.8(1)
101.2(1)
86.9(1)
86.1(2)
83.0(2)
117.0(3)
Cl(1)-Sn(1)-Cl(2)
Cl(1)-Sn(1)-O(1)
93.89(2) Cl(3)-Sn(2)-Cl(4)
91.49(5) Cl(3)-Sn(2)-O(3)
93.00(2)
87.95(5)
On the other hand for 5 both the coupling constant
and the chemical shift increase with decreasing tem-
perature (Table 2).
Cl(1)-Sn(1)-O(1)i 159.98(5) Cl(3)-Sn(2)-O(3)ii 157.55(5)
Cl(1)-Sn(1)-O(2)
Cl(1)-Sn-C(1)
82.12(5) Cl(3)-Sn(2)-O(4)
103.70(7) Cl(3)-Sn(2)-C(3)
89.36(6) Cl(4)-Sn(2)-O(3)
92.69(6) Cl(4)-Sn(2)-O(3)ii
167.39(5) Cl(4)-Sn(2)-O(4)
103.87(8) Cl(4)-Sn(2)-C(3)
69.69(8) O(3)-Sn(2)-O(3)ii
78.83(8) O(3)-Sn(2)-O(4)
158.91(9) O(3)-Sn(2)-C(3)
87.39(7) O(3)ii-Sn(2)-O(4)
93.01(8) O(3)ii-Sn(2)-C(3)
88.71(9) O(4)-Sn(2)-C(3)
86.42(5)
99.89(8)
89.30(5)
92.87(5)
172.98(6)
98.02(7)
70.48(8)
83.69(7)
169.66(8)
85.13(7)
101.71(9)
88.98(9)
Cl(2)-Sn(1)-O(1)
Cl(2)-Sn(1)-O(1)i
Cl(2)-Sn(1)-O(2)
Cl(2)-Sn(1)-C(1)
O(1)-Sn(1)-O(1)i
O(1)-Sn(1)-O(2)
O(1)-Sn(1)-C(1)
O(1)i-Sn(1)-O(2)
O(1)i-Sn(1)-C(1)
O(2)-Sn(1)-C(1)
The compound 6‚18-crown-6‚CH3CN is not soluble in
nondonor solvents such as CDCl3, and we were able to
obtain the 119Sn NMR shift only for this compound
dissolved in CD3CN (-274 ppm). In such a strong donor
solvent, it is likely that all of the originally coordinated
water molecules are displaced and that the tin atoms
are both six-coordinate under these conditions. Un-
fortunately it was also not possible to obtain a 119Sn
NMR shift for 6‚18-crown-6‚CH3CN in the solid state.
However, the 119Sn NMR shift for 7‚(2H2O) in the solid
state is at -472 ppm, consistent with the six-coordinate
tin atoms observed in the crystal structure determina-
tion.
Sn(1)-O(1)-Sn(1)i 110.31(8) Sn(2)-O(3)-Sn(2)ii 109.52(8)
Sn(1)-C(1)-C(2)
C(1)-C(2)-C(3)
115.8(2)
109.7(2)
Sn(2)-C(3)-C(2)
115.3(2)
a
Symmetry operation i: -x, -1 - y, -z; ii: 1 - x, -y, -1 - z.
The molecular structure of the di-tin molecule in 6‚18-
crown-6‚CH3CN is shown in Figure 2, and Table 3
collects some selected geometric parameters. The unit
cell comprises four molecules of each of 6, 18-crown-6,
and CH3CN, there being no molecular symmetry as-
sociated with any of the components (see Experimental
Section). The tin atoms are coordinated by three chlo-
rides, two water molecules, and the carbon atom of the
propylene bridges. The geometry about each tin atom
is distorted octahedral, the chlorides occupying facial
positions. The Sn-Cl distances with chloride trans to a
coordinated water molecule are systematically longer
than those with the chloride trans to a carbon atom.
There are no significant intermolecular interactions
(<4.0 Å) involving the tin center and either of the 18-
crown and acetonitrile molecules. The crystal structure
is essentially a layer structure being comprised of
alternate layers stacked along the crystallographic
a-direction defined by di-tin and acetonitrile molecules
on one hand and 18-crown molecules on the other. All
coordinated water molecules are involved in the hydro-
gen-bonding network in the structure.

2824 Organometallics, Vol. 20, No. 13, 2001
Zobel et al.
Ta ble 5. Cr ysta llogr a p h ic Da ta for (H2O)Cl3Sn (CH2)3Sn Cl3(H2O) (1a ), (H2O)2Cl3Sn (CH2)3Sn Cl3(H2O)2
(6‚18-cr ow n -6‚CH3CN), a n d [H2O(OH)Cl2Sn (CH2)3Sn Cl2((OH)H2O.2H2O]n (7‚2H2O)
1a
6‚18-crown-6‚CH3CN
7‚2H2O
formula
fw
C3H10Cl6O2Sn2
528.2
C17H41Cl6NO10Sn2
869.6
C3H16Cl4O6Sn2
527.4
cryst size, mm
color
temp, K
cryst syst.
space group
a, Å
b, Å
c, Å
R, deg
â, deg
γ, deg
V, Å3
0.08 × 0.23 × 0.36
colorless
173
monoclinic
C2/c
11.859(3)
6.261(5)
18.686(8)
0.11 × 0.13 × 0.29
0.11 × 0.12 × 0.14
colorless
173
triclinic
P1h
7.2652(1)
9.6400(2)
10.2992(2)
90.323(1)
103.169(1)
94.047(1)
700.43(2)
2
2.500
500
43.30
0.483-0.692
13956
30.1
3675
colorless
173
monoclinic
Cc
15.374(1)
11.641(2)
20.283(3)
90.46(3)
115.051(8)
1387(1)
4
2.528
984
47.24
0.942-1
4630
27.5
3288.5(7)
4
1.756
1728
20.49
0.660-1
5105
Z
D
calcd, g cm-3
F(000)
µ, cm-1
transmn factors
no. of data colld
θmax, deg
30.0
4233
no. of unique data
with I g 3.0σ(I)
R
1347
0.026
0.024
1.25
0.024
0.023
0.52
0.031
0.046
0.87
Rw
residual electron
density, e Å-3
Within the bc-plane, hydrogen bonds serve to link the
di-tin and acetonitrile molecules with the most notable
interactions formed between O(1)-H and N(1) [H‚‚‚N(1)
1.97 Å, O(1)‚‚‚N(1) 2.888(6) Å, and O(1)-H‚‚‚N(1) 160°]
and O(4)-H‚‚‚O(1)i [2.29 Å, 2.847(4) Å, 152°, and
symmetry operation i: x, -y, 0.5 + z]. Connections
between the layers are afforded by six hydrogen bonds
formed between the coordinated water molecules and
each of the ether oxygen atoms of the 18-crown.
Slow evaporation of a solution of 1 in aqueous solution
afforded [H2O(OH)Cl2Sn(CH2)3SnCl2(OH)H2O]n, 7, iso-
lated as a dihydrate (7‚2H2O). The solid state 119Sn
NMR shift of this material occurs at -472 ppm, con-
sistent with the six-coordinate structure determined by
the X-ray structure analysis.
The structure is comprised of hydrated polymeric
chains of [H2O(OH)Cl2Sn(CH2)3SnCl2(OH)H2O] with the
repeat unit illustrated in Figure 3; important geometric
parameters are listed in Table 4. The repeat unit
comprises two tin centers linked via a propylene bridge
in which each tin atom is also coordinated by two
chloride atoms and an oxygen atom derived from a
water molecule. The remaining positions in the distorted
octahedral coordination geometry about each tin atom
are occupied by two µ2-hydroxide groups. The crystal-
lographic asymmetric unit is completed by two water
molecules of crystallization, i.e., O(5) and O(6). The
nature of the bridging is such that centrosymmetrically
related pairs of Sn(1) atoms and of Sn(2) atoms are
linked with the result that an infinite polymeric chain
is generated as shown in Figure 4. The major distortions
in the tin atom geometries may be traced to the acute
angles induced by the Sn2(OH)2 rings, i.e., O(1)-Sn(1)-
O(1)i 69.69(8)° and O(3)-Sn(2)-O(3)ii 70.48(8)°; sym-
metry operations i: -x, -1 - y, -z and ii: 1 - x, -y,
-1 - z. The Sn-O distances within the four-membered
rings are not symmetrical, with the bond trans to a
carbon atom shorter than that trans to a chloride. While
for each tin center the Sn-Cl distances are equivalent,
F igu r e 4. Polymeric structure for [H2O(OH)Cl2Sn(CH2)3-
SnCl2(OH)H2O]n (7‚2H2O).
the Sn(1)-Cl bonds are significantly shorter than the
Sn(2)-Cl bonds. The reason for this disparity is not
obvious; however, it is noted that the Sn(1)-Owater bond
distance is significantly longer than the comparable
bond involving Sn(2). As expected, there is a complicated
network of hydrogen-bonding interactions in the lattice
and the important contacts are summarized below.

R,ω-Bis(trichlorostannyl)alkanes
Organometallics, Vol. 20, No. 13, 2001 2825
hydrochloric acid and heated at 60 °C for 24 h under magnetic
stirring. The reaction mixture was cooled to room temperature
and the solvent removed under reduced pressure to provide a
brown solid. Recrystallization from toluene yielded the diaquo
adducts 1a (2.01 g 81% yield) and 2a (2.10 g 83% yield).
The hydroxides each form a hydrogen bond. For the
first, O(1)-H‚‚‚Cl(3)iii is 2.26 Å, O(1)‚‚‚Cl(3)iii is 3.158(2)
Å, and the O(1)-H‚‚‚Cl(3)iii angle is 165°; symmetry
operation iii: -1 + x, -1 + y, z. For the other hydroxide,
O(3)-H‚‚‚O(5) is 1.88 Å, O(2)‚‚‚O(5) is 2.778(3) Å, and
O(2)-H‚‚‚O(6) is 169°, where H2O(5) is one of the water
molecules of crystallization. The coordinated water
bound to Sn(1) forms two contacts, namely, to a lattice
water O(6) (1.63, 2.749(3), 167) and, albeit weaker, to
Cl(2) (2.49, 3.206(2), 129.2; -x, -1 - y, -z). The
coordinated O(4) water molecule forms a contact with
O(6) (1.78, 2.718(3), 169; x, 1 + y, z) via the H(11) atom
and a weaker one to Cl(4) (2.54, 3.221(2), 148; 1 - x,
-y, -1 - z) via H(12).
1,1-Bis(tr ich lor osta n n yl)m eth a n e: 1H NMR δ 2.37 (s,
2J (117/119Sn-1H) ) 92/96 Hz, 1H, CH2); 13C{1H} NMR δ 21.28
1
(s, J (117/119Sn-13C) ) 635/664 Hz, 1C, CH2); 119Sn{1H} NMR
(111.85 MHz, CDCl3) concentration dependent, range from δ
-7.0 to -16.0.
1a : 1H NMR δ 2.34-2.44 (m, 2J (117/119Sn-1H) 87 Hz 2H,
SnCH2); 2.36-2.58 (m, 3J (117/119Sn-1H) 144 Hz, 1H, CH2);
13C{1H} NMR δ 20.66 (2J (117/119Sn-13C) 44 Hz); δ 32.31
(1J (117/119Sn-13C) 647/679 Hz, 3J (117/119Sn-13C) 160/168 Hz);
4
119Sn{1H} δ 1.7 (s) J (117Sn-119Sn) 595 Hz).
3
2a : 1H NMR δ 2.02-2.16 (m, J (117/119Sn-1H) 164 Hz, 1H,
The linking of the tin atoms via four-membered
Sn2OH2 rings observed in the structure of 7 is analogous
to that found in the dimeric structures of (RSnCl2-
(OH)OH2)17-20 (R ) methyl, ethyl, isopropyl, butyl,
isobutyl).
CH2); 2.26-2.44 (m, 2J (117/119Sn-1H) 86/90 Hz, 1H, CH2);
13C{1H} NMR δ 27.15 (2J (117/119Sn-13C) 53 Hz, 3J (117/119Sn-
13C) 133 Hz); δ 30.41 (1J (117/119Sn-13C) 648/680 Hz); 119Sn{1H}
δ 6.3 (s).
3: 1H NMR δ 1.58-1.80 (m, 1H, CH2); 1.90-2.14 (m,
3J (117/119Sn-1H) 170 Hz, 2H, CH2); 2.31-2.46 (m, 2J (117/119Sn-
1H) 86 Hz, 2H, CH2); 13C{1H} δ 24.1 (2J (117/119Sn-13C) 56 Hz);
δ 31.9 (1J (117/119Sn-13C) 636/666 Hz) δ 34.6 (2J (117/119Sn-13C)
117/123 Hz); 119Sn{1H}δ 4.7 (s).
Con clu sion
While we have demonstrated that Cl3Sn(CH2)nSnCl3
does undergo stepwise hydrolysis to give new oligomers,
these oligomers do not yet resemble the linked tin-12
or the tin-12 with handles motif. We are currently
investigating use of di-tin compounds linked by larger
spacers as precursors, which could yield new organotin-
oxo clusters derived from the tin-12 motif. Furthermore,
the influence of the functional X group X3Sn(CH2)nSnX3
(X ) halogen, carboxylic acid, alkoxide) on the structural
outcome of the hydrolysis will be investigated.
4: 1H NMR δ 1.24-1.62 (m, 2H, CH2, CH2); 1.94 (tt,
3
3
3J (117/119Sn-1H) 195 Hz, J (1H-1H) 7.6 Hz, J (1H-1H) 7.6 Hz,
1H, CH2); 2.38 (t, 2J (117/119Sn-1H) 81/85 Hz, 1H, 3J (1H-1H) 7.6
Hz, CH2); 13C{1H} δ 24.63 (2J (117/119Sn-13C) 60 Hz); δ 28.22; δ
32.07 (3J (117/119Sn-13C) 106/111 Hz); δ 33.24, (1J (117/119Sn-13C)
619/648 Hz); 119Sn{1H}δ 6.7 (s).
Syn th esis of 1,3-Bis(tr ibr om osta n n yl)p r op a n e (5). A
mixture of (Ph3SnCH2)2CH2 (4.65 g, 6.27 mmol) and SnBr4
(19.00 g, 43.35 mmol) was placed in a 50 mL one-neck flask
and heated at 120 °C for 48 h. The resulting yellow mixture
was distilled (bp 200-220 °C, 2 × 10-3 Torr) to give 5 (4 g
84% yield), mp 50-70 °C. Anal. Calcd for C3H6Br6Sn2: C, 4.75;
H, 0.80. Found: C, 5.34; H, 0.85. 13C{1H} NMR (75.44 MHz,
CDCl3): δ 22.29 (2J (117/119Sn-13C) 40 Hz); δ 33.52 (1J (117/119Sn-
13C) 555/582 Hz, 3J (117/119Sn-13C) 151/158 Hz). 119Sn{1H} NMR
Exp er im en ta l Section
All solvents were dried and purified by standard procedures.
NMR spectra were obtained using a Varian 300 MHz Unity
1
Plus NMR spectrometer. H, 13C, and 119Sn chemical shifts δ
4
(111.85 MHz, CDCl3): δ -168.9 (s) J (117Sn-119Sn) 499 Hz.
are given in ppm and are referenced against Me4Si and Me4Sn,
respectively. If not indicated differently, CDCl3 was used as
the NMR solvent. The melting points reported are uncorrected.
Microanalyses were performed using an elemental analyzer
MOD 1106 from Carlo Erba Strumantazione.
Gen er a l P r oced u r e for t h e Syn t h esis of r,ω-Bis-
(tr ich lor osta n n yl)a lk a n es (1-4). Meth od A. The R,ω-bis-
(triphenylstannyl)alkane (10.00 mmol) and SnCl4 (18.24 g, 8.20
mL, 70.00 mmol) were placed in a 50 mL one-neck flask and
heated for 3 h to 120-130 °C. The resulting mixture was
distilled to give the corresponding R,ω-bis(trichlorostannyl)-
alkanes.
Syn th esis of 6‚18-cr ow n -6‚H2O. To a solution of 1 (95 mg,
0.193 mmol) in 3 mL of MeOH was added 18-crown-6 (102 mg,
0.386 mmol) to afford a clear solution. After 24 h the solvent
was removed and the solid residue recrystallized from 18 mL
of CH2Cl2/hexane (5:1) to give 105 mg (64%) of colorless solid,
mp 109-113 °C. Anal. Calcd for C15H38Cl6O10Sn2‚H2O: C,
21.28; H, 4.76. Found: C, 21.25; H, 4.75. Crystals suitable for
X-ray analysis were grown from acetonitrile (mp 111-116 °C).
1H NMR δ 2.30-2.48 (m, 2H, CH2); 2.48-2.64 (m, 3J (117/119Sn-
1H) 199 Hz, 1H, CH2); 3.76 (s, 12H, CH2-crown); 13C{1H} NMR
(CD3CN) δ 23.15 (s2J (117/119Sn-13C) 54 Hz); δ 43.23 (1J (117/119Sn-
3
13C) 895/938 Hz, J (117/119Sn-13C) 202 Hz); 71.34 (s, 6C, CH2-
1,1-Bis(tr ich lor osta n n yl)m eth a n e: 2.5 g clear oil (54%
yield); bp 70-100 °C, 5 × 10-3 Torr.
crown); 119Sn{1H} (CD3CN) δ -274.1 (s, W1/2 approximately
800 Hz).
1,3-Bis(tr ich lor osta n n yl)p r op a n e, 1: 3.7 g colorless solid
(75% yield); bp 120-130 °C, 10-3 Torr; recrystallization from
CHCl3 gave the diaquo adduct 1a , mp 97-98 °C. Anal. Calcd
for C3H6Cl6Sn2‚2H2O: C, 6.82; H, 1.91. Found: C, 7.01; H, 1.87.
1,4-Bis(tr ich lor osta n n yl)bu ta n e, 2: 3.37 g colorless solid
(67% yield); bp 130-150 °C, 10-3 Torr; recrystallization from
CHCl3 gave the diaquo adduct 2a , mp 99-101°. Anal. Calcd
for C4H8Cl6Sn2‚2H2O: C, 8.86; H, 2.23. Found: C, 8.85; H, 1.84.
1,5-Bis(tr ich lor osta n n yl)p en ta n e, 3: 3.90 g clear oil (75%
Syn th esis of (7‚2H2O). A solution of 1 (50 mg, 0.102 mmol)
in 1 mL of H2O was placed on a watch glass and slowly
evaporated to give 47 mg (94%) of a crystalline solid, mp 110-
135 °C. Anal. Calcd for C3H12Cl4O4Sn2‚2H2O: C, 6.83; H, 3.06.
Found: C, 6.95; H, 3.02.
X-r a y Cr ysta llogr a p h y. Data were collected at 173 K
employing graphite-monochromatized Mo KR radiation, λ )
0.71073 Å, on a Rigaku AFC7R diffractometer for 1a and 6‚
18-crown-6‚CH3CN and a Nonius CCD for 7‚2H2O. Corrections
were made for Lorentz and polarization effects (1a , 6‚18-crown-
6‚CH3CN,34 735) as well as for absorption employing an
yield); bp 140-180 °C, 2 × 10-3 Torr. Anal. Calcd for C5H10
-
Cl6Sn2: C, 11.54; H, 1.94. Found: C, 12.10; H, 1.91.
1,8-Bis(tr ich lor osta n n yl)octa n e, 4: 4.46 g clear oil (80%
yield); bp 200-240 °C, 5 × 10-3 Torr. Anal. Calcd for C8H16
-
Cl6Sn2: C, 17.09; H, 3.10. Found: C, 17.61; H, 2.93.
(34) teXsan: Structure Analysis Software; Molecular Structure
Corp.: The Woodlands, TX, 1997.
(35) Walker, N.; Stuart, D. Acta Crystallogr. Sect. A 1983, 39, 158.
Met h od B. The appropriate R,ω-bis(triphenylstannyl)-
alkane (5.00 mmol) was mixed with 40 mL of concentrated

2826 Organometallics, Vol. 20, No. 13, 2001
Zobel et al.
empirical method36 for 1a and 6‚18-crown-6‚CH3CN and a
numerical method for 7‚2H2O.37 The structures were solved
by direct-methods38 and each refined by a full-matrix least-
squares procedure based on F.34 Non-hydrogen atoms were
refined with anisotropic displacement parameters, and H
atoms were included in the model in their calculated positions
(C-H 0.95 Å); O-H atoms were located from difference maps
except for one H of a lattice water molecule (with the O(6)
atom) in 7‚2H2O. The structure of 6‚18-crown-6‚CH3CN was
modeled in the noncentrosymmetric space group Cc. Support
for this choice is found in the distribution of the E-statistics
and well as in the successful refinement. The use of the
PLATON program39 shows the presence of pseudosymmetry
in the lattice, but several atoms did not comply to the higher
symmetry required by C2/c, perhaps indicating disorder not
evident in the low-symmetry space group. The absolute
structure was not determined. The refinements were continued
until convergence with the application of a weighting scheme
2
of the form w ) 1/[σ2(Fo) + g|Fo| ]; g ) 0.00002, 0.00002, and
0 for 1a , 6‚18-crown-6‚CH3CN, and 7‚2H2O, respectively.
Diagrams of the molecules were drawn with ORTEP40 plotted
at the 50% probability level.
Ack n ow led gm en t. We are grateful to the Austra-
lian Research Council (ARC) for financial support and
to Dr. G. D. Fallon (Monash University) for X-ray data
collection on compound 7‚2H2O.
Su p p or tin g In for m a tion Ava ila ble: Further details of
the structure determination including atomic coordinates, bond
distances and angles, and thermal parameters. This material
is available free of charge via the Internet at http://pubs.acs.org.
(36) Denzo-SMN: Otwinowski, Z.; Minor, W. In Methods Enzymol.
1997, 276A, 307. Carter, C. W., J r., Sweet, R. M., Eds. Academic
Press: New York.
(37) maXus: Mackay, S.; Gilmore, C. J .; Edwards, C.; Tremayne,
M.; Stewart, N.; Shackland, K. University of Glasgow, Scotland, UK.;
Nonius BV, Delft, The Netherlands; Mac Science Co. Ltd, Yokohama,
J apan, 1998.
OM010202J
(38) Beurskens, P. T.; Admiraal, G.; Beurskens, G.; Bosman, W. P.;
Garc´ıa-Granda, S.; Smits, J . M. M.; Smykalla, C. The DIRDIF program
system, Technical Report of the Crystallography Laboratory; University
of Nijmegen: The Netherlands, 1992.
(39) Spek, A. L. Acta Crystallogr., Sect. A 1990, 46, C34.
(40) J ohnson, C. K. ORTEP. Report ORNL-5138; Oak Ridge Na-
tional Laboratory: Oak Ridge, TN, 1976.