o-bis(haloorganostannyl)benzenes as powerful bidentate Lewis acids toward halide ions

Article abstract of DOI:10.1021/om980703d

The synthesis of the o-phenylene-bridged ditin species o-C ₆H₄(SnXMe₂)₂ (2, X = Cl; 4, X = F) and o-C₆H₄(SnCl₂Me)₂ (3) is reported and the crystal structures of [o-C₆H₄(SnClMe ₂)₂· Cl]^-[(Ph₃N) ₂P]⁺ (5) and [o-C₆H₄(SnClMe ₂)₂·F]^-[K·C₂₀H ₂₄O₆]⁺ (7) are described. Variable-temperature ¹¹⁹Sn and ¹⁹F NMR studies indicate that 2 and 4 act as bidentate Lewis acids toward chloride and fluoride ions exclusively forming the stable anionic 1:1 complexes 5, 7, and [o-C₆H₄(SnFMe ₂)₂·F]^-[Et₄N]⁺ (8). No formation of dianionic 1:2 adducts was observed even with excess of halide ions. The affinity of 2 toward fluoride is greater than toward chloride. Reaction of 2 with HMPA gives the neutral complex o-C₆H ₄(SnClMe₂)₂·(Me₂N) ₃PO (10), the crystal structure of which is also described.

Full text of DOI:10.1021/om980703d

5858
Organometallics 1998, 17, 5858-5866
o-Bis(h a loor ga n osta n n yl)ben zen es As P ow er fu l
Bid en ta te Lew is Acid s tow a r d Ha lid e Ion s†
Reiner Altmann, Klaus J urkschat,* and Markus Schu¨rmann
Lehrstuhl fu¨r Anorganische Chemie II der Universita¨t Dortmund,
D-44221 Dortmund, Germany
Dainis Dakternieks* and Andrew Duthie
School of Biological and Chemical Sciences, Deakin University,
Geelong, Victoria 3217, Australia
Received August 17, 1998
The synthesis of the o-phenylene-bridged ditin species o-C6H4(SnXMe2)2 (2, X ) Cl; 4, X
) F) and o-C6H4(SnCl2Me)2 (3) is reported and the crystal structures of [o-C6H4(SnClMe2)2‚
Cl]-[(Ph3N)2P]+ (5) and [o-C6H4(SnClMe2)2‚F]-[K‚C20H24O6]+ (7) are described. Variable-
temperature 119Sn and 19F NMR studies indicate that 2 and 4 act as bidentate Lewis acids
toward chloride and fluoride ions exclusively forming the stable anionic 1:1 complexes 5, 7,
and [o-C6H4(SnFMe2)2‚F]-[Et4N]+ (8). No formation of dianionic 1:2 adducts was observed
even with excess of halide ions. The affinity of 2 toward fluoride is greater than toward
chloride. Reaction of 2 with HMPA gives the neutral complex o-C6H4(SnClMe2)2‚(Me2N)3PO
(10), the crystal structure of which is also described.
In tr od u ction
as Lewis acids in these host molecules include for
instance B,10 Al,11 In,4 Si,6c,7 Ge,8 Sn,2,3,5,6 and Hg.12
One observation from the investigations reported so
far is that high guest selectivity and high stability of
the host-guest complexes are achieved in cases where
the host shows a high degree of preorganization and
rigidity. This holds especially for the o-phenylene-
bridged dimercury12 and disilicon13 species of type A.
The power of 1,8-bis(alkylstannyl)naphthalene in alky-
lation reactions has been demonstrated recently.14a
Diels-Alder reactions were also shown to be catalyzed
by bidentate tin-containing Lewis acids.14b
In recent years the selective complexation of anions
and neutral donor molecules by tailor-made molecular
hosts has been a subject of growing interest.1 Part of
this general concept is the synthesis of multidentate
Lewis acids in which the latter are incorporated in open
chain2-4 or cyclic structures.5-9 Elements which function
† This paper includes part of the intended Ph.D. thesis of R.
Altmann.
(1) (a) Pierre, J . L.; Baret, P. Bull. Soc. Chim. Fr. 1983, II-367 and
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97, 1609 and references cited. (d) Beer, P. D.; Smith, D. K. Progress in
Inorganic Chemistry; Wiley: New York, 1997; Vol. 46, p 1, references
cited. (e) Antonisse, M. M. G.; Reinhoudt, D. N. Chem. Commun. 1998,
443.
In continuation of our studies on tin-based bidentate
Lewis acids,3a-f we report here on the synthesis of the
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10.1021/om980703d CCC: $15.00 © 1998 American Chemical Society
Publication on Web 12/01/1998

o-Bis(haloorganostannyl)benzenes as Lewis Acids
Organometallics, Vol. 17, No. 26, 1998 5859
Sch em e 1
corresponding o-phenylene-bridged derivatives of type
B and on their complexation behavior toward chloride
ions, fluoride ions, and HMPA.
Resu lts a n d Discu ssion
Sch em e 2
Syn th etic Asp ects. The synthesis of o-bis(trimeth-
ylstannyl)benzene (1) has been reported but yield15a-c
and purity15a were not satisfying. Modification of the
reported procedure15a provided compound 1 in 70%
yield.
Treatment of 1 with 2 molar equiv of Me2SnCl2 or 2
molar equiv of SnCl4 afforded o-bis(dimethylchlorostan-
nyl)benzene (2) and o-bis(methyldichlorostannyl)ben-
zene (3), respectively, in high yield (Scheme 1).
Reaction of 2 with potassium fluoride gave almost
quantitatively o-bis(dimethylfluorostannyl)benzene (4)
(eq 1).
Reaction of 2 with Et4NF‚2H2O gave the anionic
fluoride adduct [o-C6H4(SnClMe2)2‚F]- as crystalline
[Et4N]+ salt 6 (eq 2), which was of insufficient quality
for X-ray analysis. Better quality crystals of anionic
[o-C6H4(SnClMe2)2‚F]- were obtained as the potassium
salt [o-C6H4(SnClMe2)2‚F]- [K‚dibenzo-18-crown-6]+ (7),
from reaction of o-bis(dimethylchlorostannyl)benzene (2)
and equimolar quantities of potassium fluoride and
dibenzo-18-crown-6 (eq 2).
Reaction of o-bis(dimethylfluorostannyl)benzene (4)
with Et4NF‚2H2O afforded the fluoride complex [o-C6H4-
(SnFMe2)2‚F]- [Et4N]+ (8), and reaction of 4 with
potassium fluoride and 18-crown-6 gave the potassium
salt [o-C6H4(SnFMe2)2‚F]- [K‚18-crown-6]+ (9) (eq 2).
Compounds 2-9 are colorless solids. The chloro-
substituted derivatives 2 and 3 as well as the chloride
and fluoride complexes 5-9 are soluble in common
organic solvents such as CH2Cl2, CHCl3, toluene, and
THF. The fluoro-substituted derivative 4 is almost
insoluble in common organic solvents.
Attempts failed to prepare 1,8-bis(dimethylchlorostan-
nyl)naphthalene C10H6-1,8-(SnClMe2)2 by reaction of
1,8-bis(trimethylstannyl)naphthalene16 C10H6-1,8-(Sn-
Me3)2 with dimethyldichlorostannane. The reaction gave
7,7,14,14-tetramethyldinaphtho[1,8-bc:1′,8′-fg][1,5]distan-
nocine17 as the major product (Scheme 2).
The treatment of 2 with 1 molar equiv [(Ph3P)2N]+Cl-
afforded the corresponding chloride complex [o-C6H4-
(SnClMe2)2•Cl]-[(Ph3P)2N]+ (5) as crystalline solid (eq
2).
Treatment of o-bis(dimethylchlorostannyl)benzene (2)
with HMPA afforded the neutral 1:1 complex o-C6H4-
(SnClMe2)2‚(Me2N)3PO (10) as a crystalline colorless
solid (eq 3).
Com p lexa tion Beh a vior in Solu tion of Com -
p ou n d s 2 a n d 3 tow a r d Ch lor id e Ion s. Information
on the complexation behavior of compounds 2 and 3
toward anions is provided by NMR spectroscopy and
electrospray mass spectrometry.
(15) (a) Wursthorn, K. R.; Kuivila, H. G. J . Organomet. Chem. 1977,
140, 29. (b) Eisch, J . J .; Kotowicz, B. W. Eur. J . Inorg. Chem. 1998,
761. (c) Evnin, A. B.; Seyferth, D. J . Am. Chem. Soc. 1967, 89, 952.
(16) Seyferth, D.; Vick, S. C. J . Organomet. Chem. 1977, 141, 173.
(17) Meinwald, J .; Knapp, S.; Tatsuoka, T. Tetrahedron. Lett. 1977,
26, 2247.

5860 Organometallics, Vol. 17, No. 26, 1998
Altmann et al.
under standard conditions (20 °C, c ) 0.1 mol/L), lie
between 4200 and 11 000 M-1. It is more reliable to
directly compare the complexation behavior of the hosts
2 and 3 toward chloride (eq 4; Table 1) as was recently
shown by Tamao et al. for related silicon species.13a
Equimolar amounts of [Ph3PdNdPPh3]+Cl- and the
corresponding organotin compounds A-C (Table 1, eq
4) were dissolved in 2 mL of dichloromethane (c ) 0.2-
0.25 mol/L), and the resulting solutions were investi-
gated by 119Sn NMR spectroscopy. From the chemical
shifts observed and the calibration curves shown in
Figure 1, the molar fractions m, n, and o can be
estimated.
From these experiments the following qualitative
sequence results of the affinity of organotin chlorides
toward chloride ions: Ph3SnCl , Ph2SnCl2 , (Ph2-
ClSnCH2)2 ≈ (Ph2ClSn)2CH2 ≈ C6H4(SnClMe2)2 (2) ,
(PhCl2Sn)2CH2 ≈ C6H4(SnCl2Me)2 (3).
F igu r e 1. Plot of 119Sn NMR chemical shift (ppm) versus
molar ratio [(Ph3P)N]+ Cl-/compound.
The sequence shows (i) the bidentate ditin species to
be more efficient than the monotin derivatives, (ii) the
methylene-, dimethylene-, and o-phenylene-bridged bis-
(diorganochlorostannyl) derivatives to be in the same
order of magnitude, (iii) the bidentate tetrachlorides to
be more efficient than the bidentate dichlorides, and (iv)
the methylene- and o-phenylene-bridged bis(organo-
dichlorostannyl) species to be in the same order of
magnitude.
The 119Sn NMR chemical shifts of the chloro-substi-
tuted derivatives 2 and 3 to which various amounts of
[(Ph3P)2N]+Cl- have been added are shown in Figure
1. The corresponding slopes for Ph2SnCl2 and the
methylene- and dimethylene-bridged ditin compounds
(Ph2ClSn)2CH2, (PhCl2Sn)2CH2, and (Ph2ClSnCH2)2 are
given for comparison.3c,18 For the dichloro derivative 2
the measurements clearly indicate the formation of a
one-to-one complex with chloride ion, as was confirmed
by isolation of the chloride complex 5 and as was to be
expected from comparison with the behavior of the
aliphatic analogue (Ph2ClSnCH2)2.3c The structure in
solution of chloride complex 5 is very likely to be similiar
to its solid-state structure (see below) with the two tin
atoms being bridged by chloride resulting in trigonal
bipyramidal configurations. This is supported by obser-
vation of increased 2J (1H-119/117Sn) and 1J (13C-119/117Sn)
couplings of 72/69 and 530/506 Hz, respectively, in
compound 5 in comparison with the corresponding
couplings measured for compound 2 (61/59, 408/389 Hz).
The negative-ion electrospray mass spectrum of a
solution of o-C6H4(SnClMe2)2 (2) in acetonitrile shows
an isotopic cluster pattern centered at m/z ) 481 which
is consistent with self-ionization to give the monoanion
[2 + Cl]-. The positive-mode electrospray mass spec-
trum of the same solution gives spectra consistent with
[2 - 2Cl + OH]+ as major species (m/z ) 391) and small
amounts of [2 - Cl]+ (m/z ) 409) and [2 - 2Cl + OH +
MeCN]+ (m/z ) 432). Interestingly, also present are
small quantities of dimeric species [2‚2 - 4Cl + O +
OH]+ (m/z ) 781), [2‚2 - 3Cl + O]+ (m/z ) 799), and
[2‚2 - 3Cl + 2OH]+ (m/z ) 817).
The negative-ion electrospray mass spectrum of the
complex [o-C6H4(SnClMe2)2‚Cl]-[(Ph3P)2N]+ (5) in aceto-
nitrile shows an isotopic cluster pattern of [2 + Cl]- at
m/z )481 and a less intense signal consistent with [2 -
Cl + O]- (m/z ) 425). The positive-mode electrospray
mass spectrum shows in addition to the cluster of
[(Ph3P)2N]+ at m/z ) 538 a minor ion-paired species [2
+ Cl + 2‚(Ph3P)2N]+ (m/z ) 1557). After addition of 1
molar equiv of chloride ion (as its tetrabutylammonium
salt), the spectra in both modes do not change and there
is no evidence for dianionic species.
The negative-ion electrospray mass spectrum of a
solution of o-bis(methyldichlorostannyl)benzene (3) in
acetonitrile shows an isotopic cluster pattern centered
at m/z ) 521 which is consistent with self-ionization to
give the monoanion [3 + Cl]-. There are also weaker
cluster patterns (approximately 5-10% relative abun-
dance) consistent with the presence of [3 - Cl + O]-
(m/z ) 467), [3 + OH]- (m/z ) 503), and [2‚3 - 7Cl +
4O]- (m/z ) 787). The positive-ion electrospray mass
spectrum carries very little ion current and contains
weak signals consistent with the presence of [3 - 2Cl
+ OH]+ (m/z ) 431), [3 - 2Cl + OH + MeCN]+ (m/z )
1
The chloride bridge in 5 is symmetric on the H, 13C,
and 119Sn NMR time scales, i.e., the methyl groups as
well as the tin atoms are equivalent.
The tetrachloro derivative 3 forms both a one-to-one
and a one-to-two complex as is indicated by observation
of a inflection point at about δ 119Sn ) -150 ppm (Figure
1). None of these complexes were isolated. A similar
complexation behavior is observed for (PhCl2Sn)2CH2,
whereas Ph2SnCl2 forms a one-to-one complex with
chloride (see Figure 1).
Formation constants Ka of one-to-one Lewis-acid/
Lewis-base complexes can be estimated by application
of the Benesi-Hildebrandt treatment.19 However, the
absolute Ka values calculated from the NMR experi-
ments have to be taken with great caution as we have
obtained different values from several independent
measurements on the same complex. For instance, the
Ka values for compound 2, which have been obtained
(18) Dakternieks, D.; J urkschat, K.; Wu, H.; Tiekink, E. R. T.
Organometallics 1993, 12, 2788.
(19) (a) Benesi, H. A.; Hildebrand, J . H. J . Am. Chem. Soc. 1949,
71, 2703. (b) Bergeron, R. J .; Channing, M. A.; Gibeily, G. J .; Pillor,
D. M. J . Am. Chem. Soc. 1977, 99, 5146.

o-Bis(haloorganostannyl)benzenes as Lewis Acids
Organometallics, Vol. 17, No. 26, 1998 5861
Ta ble 1. Com p a r ison of th e Com p lexa tion Beh a vior tow a r d Ch lor id e Ion s of Selected Tin Con ta in in g
Bid en ta te Lew is Acid s
compounds
119Sn NMR chemical shift δ/ppm
A
B
C
m [A‚Cl]-
n [B‚Cl]-
o [C‚Cl]-
2
2
2
2
2
2
3
n . m
35.2
-17.7
-26.7
51.6
43.0
-48.1
-150.6
-91.6
-68.9
-3.9
-140.4
-129.8
-223.5
-82.9
(Ph2ClSn)2CH2
(Ph2ClSnCH2)2
(Ph2ClSn)2CH2
(PhCl2Sn)2CH2
Ph2SnCl2
m ≈ n
m ≈ n
(PhCl2Sn)2CH2
o . m ≈ n
-135.3
n . m
Ph3SnCl
Ph3SnCl
m . n ≈ o
n . o
-54.2
-69.4
Ph2SnCl2
(PhCl2Sn)2CH2
3
m ≈ n
-89.5
472), and the dimeric species [2‚3 - 5Cl + 2O]+ (m/z )
825), [2‚3 - 4Cl + O + OH]+ (m/z ) 863), and [2‚3 -
3Cl + O]+ (m/z ) 881).
The 119Sn NMR spectrum in CD2Cl2 at room temper-
ature of the fluoride complex 8 displays a doublet of
doublets resonance at δ ) -138.3 ppm (1J (119Sn - 19F)
) 1954/1187 Hz). The 19F NMR spectrum of the same
but diluted solution exhibits one triplet resonance at δ
) -126.8 ppm (1J (19F - 119Sn) ) 1172 Hz, 2J (19F - 19F)
) 84 Hz) and a doublet resonance at δ ) -155.4 ppm
(1J (19F - 119Sn) ) 1912 Hz, 2J (19F - 19F) ) 83 Hz) with
an integral ratio of 1:2. The spectra are consistent with
a structure containing one bridging and two terminal
fluorine atoms as shown in eq 2. Addition of 1 molar
equiv of fluoride ion gives no evidence for formation of
a dianionic fluoride complex.
The negative-ion electrospray mass spectrum of the
complex [K‚dibenzo-18-crown-6]+[o-C6H4(SnClMe2)2‚F]-
(7) in acetonitrile shows an isotopic cluster of [2 + F]-
at m/z ) 463 and weak signals of [2 + Cl]- (m/z ) 481)
and [2 + 2F - Cl]- (m/z ) 447). The positive-mode
electrospray mass spectrum of 7 contains the expected
clusters of potassium and sodium dibenzo-18-crown-6
salts. Addition of 1 molar equiv of fluoride ion (as its
tetrabutylammonium salt) provides no evidence for
dianionic species.
Com p lexa tion Beh a vior in Solu tion of Com -
p ou n d s 2-5 tow a r d F lu or id e Ion s. The 119Sn NMR
spectrum at room temperature of the fluoride complex
6 shows a doublet at δ ) -100.8 ppm (1J (119Sn - 19F)
) 1107 Hz) and the 19F NMR spectrum displays a single
resonance at δ ) -137.1 ppm (1J (19F - 119Sn) ) 1108
Hz). These results are consistent with a bridging
fluoride and demonstrate the high kinetic stability of 6
in comparison with the related complexes [(Ph2ClSn)2-
(CH2)n‚F]- (n ) 1, 3) for which no 119Sn NMR spectra
could be obtained at room temperature.3f The high
kinetic stability of 6 on the 119Sn NMR time scale is
further illustrated by the absence of any coalescence
phenomena in its 119Sn NMR spectrum in pyridine at
100 °C. However, the 119Sn NMR spectrum in CH2Cl2
of 6 to which has been added 1 molar equiv of 2 shows
no signal at room temperature and a very broad signal
at -44 ppm (W1/2 ≈ 1600 Hz) at -80 °C, indicating fast
exchange.
Treatment of the chloride complex 5 with an equimo-
lar amount of potassium fluoride in dichloromethane
gave quantitative in situ formation of the fluoride
complex 6a (eq 5).
After addition of 1 molar equiv of fluoride ion (as its
tetrabutylammonium salt) to an acetonitrile solution of
o-C6H4(SnCl2Me)2 (3) the negative-ion electrospray mass
spectrum shows the isotopic cluster pattern of [3 + Cl]-
at m/z ) 521 (100% relative abundance) and [3 + F]-
at m/z ) 505 (80% relative abundance). There is again
a weaker cluster pattern for [3 - Cl +O]- at m/z ) 467.
The positive mode shows a weak signal consistent with
[3 - 2Cl + OH]+ at m/z ) 431.
The negative-ion electrospray mass spectrum of o-C6H4-
(SnFMe2)2 (4) in acetonitrile solution contains an iso-
topic cluster pattern for [4 - F + 2Cl]- (m/z ) 463), [4
+ Cl]- (m/z ) 446), and [4 + F]- (m/z ) 431). There are
also weaker signals (approximately 2% relative abun-
dance) centered at m/z ) 843 and m/z ) 859 consistent
with the dimeric species [2‚4 + F]- and [2‚4 + Cl]-. The
positive-ion electrospray mass spectrum carries very
little ion current and contains weak signals consistent
with the presence of [4 - 2F + OH]+ (m/z ) 391),
[4+H]+ (m/z ) 413), [4 + Na]+ (m/z ) 435), [4 + K]+
(m/z ) 451), [4 + Na + MeCN]+ (m/z ) 476), and the
dimeric compound [2‚4 - 3F + 2OH]+ (m/z ) 801).
The fluoride complex 6b was formed quantitatively
in situ by reaction of o-bis(dimethylchlorostannyl)-
benzene (2) with [Ph3SnF2]-[Bu4N]+ (eq 6). Both reac-
tions illustrate the high affinity of the bidentate Lewis
acid 2 toward fluoride.
The negative-ion electrospray mass spectrum of the
complex [K‚18-crown-6]+[o-C6H4(SnFMe2)2‚F]- (9) in
acetonitrile shows an isotopic cluster pattern for [4 +
F]- at m/z ) 431 and a less intense signal consistent
with [4 + Cl]- (m/z ) 447). The presence of dimeric
species is again confirmed by weak isotopic clusters
(approximately 3% relative abundance) at m/z ) 843

5862 Organometallics, Vol. 17, No. 26, 1998
Altmann et al.
and m/z ) 903 assigned to [2‚4 + F]- and [2‚4 + Br].
Related dimeric mercury complexes [(o-C6H4(HgCl)2)2‚
Cl]-[Ph4P]+ and [(o-C6H4(HgCl)2)2‚Cl]-[Bu4N]+ were
isolated and fully characterized.12a-d The positive-mode
electrospray mass spectrum contains in addition to the
cluster of [K‚18-crown-6]+ at m/z ) 303 a very weak
signal assigned to a species with two countercations [4
+ F + 2‚(K‚18-crown-6)]+ (m/z ) 1037).
Addition of 1 molar equiv of Bu4NF shows again the
cluster pattern of [4 + F]- as the most intense signal
and weak isotopic clusters (approximately 2% relative
abundance) for the dimeric species [2‚4 + F]- at m/z )
843 and [2‚4 + 2F + K]- at m/z ) 901. There is no
evidence for dianionic species. The positive mode shows
weak signals for [4 + F + (K‚18-crown-6) + Bu4N]+ at
m/z ) 976 and [4 + F + 2‚(K‚18-crown-6)]+ at m/z )
1037.
F igu r e 2. General view (SHELXTL-PLUS) of a molecule
of 5 showing 30% probability displacement ellipsoids and
the atom numbering.
The complexation behavior toward fluoride of o-bis-
(methyldichlorostannyl)benzene (3) and of related [(Me3-
Si)2CH(Cl2)Sn]2CMe2 is more complex and will be a
subject of a forthcoming paper.
Rea ction of o-bis(d im eth ylch lor osta n n yl)ben -
zen e (2) w ith HMP A. The complexes of bis(halodiphen-
ylstannyl)methane, 1,2-bis(halodiphenylstannyl)ethane,
and bis((diphenylchlorostannyl)methyl)phenylchloro-
stannane with the nonbridging donor HMPA have
previously been described.3a,c,g
The 119Sn NMR spectrum at room temperature of an
equimolar solution of 2 and HMPA in CD2Cl2 shows a
broad signal at δ ) -71 ppm (W1/2 ) 650 Hz). The 31P
NMR spectrum at room temperature displays a signal
at 24.6 ppm without 119/117Sn NMR satellites. Both
spectra indicate a fast exchange process. At -80 °C the
119Sn NMR spectrum splits into two sharp resonances,
a singlet at -52.9 ppm and a doublet at -98.9 ppm
(2J (119Sn-31P) ) 140 Hz) with integral ratio of 1:1. In
addition, there are three signals of lower intensity (20%
of the major resonances) at -79.1, -82.2, and -136.7
ppm for which no assignment is made. The 31P NMR
spectrum at -80 °C shows the signal at -24.5 ppm with
an unresolved 2J (31P-119/117Sn) coupling of 135 Hz. Both
119Sn and 31P NMR are consistent with formation of the
neutral complex o-C6H4(SnClMe2)2‚HMPA (10) and are
similar to those for the related complex (Ph2ClSnCH2)2‚
HMPA.3c
F igu r e 3. General view (SHELXTL-PLUS) of a molecule
of 7 showing 30% probability displacement ellipsoids and
the atom numbering.
After addition of a second molar equivalent of HMPA,
the 119Sn NMR spectrum differs only in the intensity of
the signal at -79.1 ppm (reaching half of the intensity
of the major resonances) for which no assignment could
be made. There was no evidence for the formation of a
1:2 complex o-C6H4(SnClMe2)2‚2HMPA.
Molecu la r Str u ctu r es of 5, 7, a n d 10. The molec-
ular structures of 5, 7, and 10 are illustrated in Figures
2-4, respectively, showing the crystallographic num-
bering scheme and confirming the stoichiometries of the
compounds. Unit cell data, refinement details, and
selected interatomic parameters are listed in Tables 2
and 3 and provide detailed information on the molecular
geometries.
F igu r e 4. General view (SHELXTL-PLUS) of a molecule
of 10 showing 30% probability displacement ellipsoids and
the atom numbering.
of dichloromethane. There is an interaction between the
K
+ ion in the crown ether and Cl(1) confirmed by a Cl-
(1)-K(1) distance of 3.133(3) Å, which is comparable to
the K-Cl distance in potassium chloride (3.14 Å).20
The tin atoms in the anions of 5 and 7 exhibit a
trigonal bipyramidal configuration with the axial posi-
tions being occupied by Cl(1), X for Sn(1) and Cl(2), X
for Sn(2) (5, X ) Cl(3); 7, X ) F). The carbon atoms C(1),
C(7), C(8) (for Sn(1)) and C(2), C(9), C(10) (for Sn(2))
define the equatorial planes. The tin atoms in 5 are
displaced by 0.148(2) Å (Sn(1)) and 0.099(2) Å (Sn(2))
The lattice of 5 and 7 comprises discrete [o-C6H4(Sn-
Me2Cl)2‚Cl]- and [o-C6H4(SnMe2Cl)2‚F]- anions, respec-
tively, and countercations (5, [(Ph3P)2N]+; 7, [K‚dibenzo-
18-crown-6]+). For 5 there is no significant interionic
contact. Compound 7 crystallizes with a 0.5 molar equiv
(20) Huheey, J . E. Anorganische Chemie, Prinzipien von Struktur
und Reaktivita¨t; Walter de Gruyter: Berlin, 1988.

o-Bis(haloorganostannyl)benzenes as Lewis Acids
Organometallics, Vol. 17, No. 26, 1998 5863
Ta ble 2. Cr ysta llogr a p h ic Da ta of 5, 7, a n d 10
5
7
10
formula
fw, g/mol
cryst syst
cryst size, mm
space group
a, Å
C
46H46Cl3NP2Sn2
C30H40Cl2FKO6Sn2‚.5 CH2Cl2
905.46
monoclinic
0.40 × 0.20 × 0.10
C2/c
30.513(4)
9.858(1)
25.093(4)
90.37(1)
7547.7(17)
8
C16H34Cl2N3OPSn2
623.71
orthorhombic
0.20 × 0.15 × 0.15
P212121
9.968(1)
15.070(1)
17.178(1)
1018.51
monoclinic
0.30 × 0.20 × 0.18
P21/n
13.380(1)
24.361(1)
14.360(1)
95.314(1)
4595.9(5)
4
b, Å
c, Å
â, deg
V, Å3
2580.4(3)
4
1.605
1.676(2)
2.214
1232
Z
F
F
calcd, mg/m3
meas, mg/m3
1.472
1.466(1)
1.362
1.594
1.637(12)
1.688
µ, mm-1
F(000)
2040
3608
θ range, deg
4.53 to 25.58
-15 e h e 15
-29 e k e 29
-17 e l e 17
61416
2.09 to 24.98
-1 e h e 36
-1 e k e 11
-29 e l e 29
7946
100.0
6635/0.018
4106
3.41 to 25.99
-12 e h e 12
-16 e k e 16
-21 e l e 21
36231
index ranges
no. of reflns collcd
completeness to θmax
no. of indep reflns/Rint
no. of reflns obsd with (I > 2σ(I))
abs corrn
97.1
94.9
8316/0.053
4698
4871/0.066
3769
nma
ψ-scan
1.00/0.825
399
nma
Tmax/Tmin
no. of refined params
493
0.855
238
0.942
GOF (F2)
1.020
R1 (F) (I > 2σ(I))
wR2 (F2) (all data)
(∆/ σ)max
0.0612
0.0321
0.001
0.1000
0.0388
0.001
0.536/-0.398
0.0502
0.0265
0.001
largest diff. peak/hole, e/Å3
0.372/-0.343
0.372/-0.594
a
nm ) not measured.
Ta ble 3. Selected In ter a tom ic Bon d Dista n ces (Å) a n d An gles (d eg) for 5, 7, a n d 10
compound
5
7
10
X ) Cl(3); Y(1) ) Cl(1); Y(2) ) Cl(2)
X ) F(1); Y(1) ) Cl(1); Y(2) ) Cl(2)
X ) Cl(1); Y(1) ) O(1); Y(2) ) Cl(2)
Bond Distances
2.139(3)
2.213(3)
2.608(2)
2.532(2)
2.152(5)
2.129(6)
2.119(7)
2.171(4)
2.127(6)
2.113(5)
Sn(1)-X
2.7414(11)
2.8027(10)
2.5267(11)
2.4762(11)
2.139(4)
2.127(3)
2.128(3)
2.153(3)
2.116(3)
2.6108(13)
2.7831(13)
2.236(3)
2.4831(13)
2.150(4)
2.115(5)
2.109(4)
2.163(4)
2.113(5)
2.115(5)
Sn(2)-X
Sn(1)-Y(1)
Sn(2)-Y(2)
Sn(1)-C(1)
Sn(1)-C(7)
Sn(1)-C(8)
Sn(2)-C(2)
Sn(2)-C(9)
Sn(2)-C(10)
2.109(4)
Bond Angles
177.82(9)
117.1(2)
123.5(2)
118.8(3)
95.17(12)
90.0(2)
X-Sn(1)-Y(1)
177.44(3)
126.20(14)
110.5(2)
122.7(2)
94.64(10)
90.64(11)
92.96(12)
87.32(10)
86.87(11)
87.88(12)
127.3(2)
114.8(3)
178.84(4)
121.00(14)
116.2(2)
121.3(2)
93.81(9)
93.00(12)
95.21(13)
85.29(9)
86.85(12)
85.85(13)
126.3(3)
115.0(3)
91.66(3)
176.87(8)
117.73(18)
119.56(17)
122.7(2)
90.52(13)
87.71(18)
89.90(16)
90.32(11)
89.22(16)
92.31(14)
126.2(3)
C(1)-Sn(1)-C(7)
C(1)-Sn(1)-C(8)
C(7)-Sn(1)-C(8)
C(1)-Sn(1)-Y(1)
C(7)-Sn(1)-Y(1)
C(8)-Sn(1)-Y(1)
C(1)-Sn(1)-X
92.0(2)
86.95(14)
88.7(2)
C(7)-Sn(1)-X
C(8)-Sn(1)-X
C(2)-C(1)-Sn(1)
C(6)-C(1)-Sn(1)
X-Sn(2)-Y(2)
87.3(2)
122.0(3)
120.2(3)
177.68(9)
119.6(2)
116.6(2)
121.8(2)
96.81(14)
92.2(2)
95.2(2)
85.0(2)
85.7(2)
85.3(2)
115.8(3)
175.54(5)
116.59(18)
119.88(18)
121.9(2)
97.00(11)
92.66(16)
93.14(17)
86.84(11)
83.58(16)
86.85(17)
126.7(3)
C(2)-Sn(2)-C(9)
C(2)-Sn(2)-C(10)
C(9)-Sn(2)-C(10)
C(2)-Sn(2)-Y(2)
C(9)-Sn(2)-Y(2)
C(10)-Sn(2)-Y(2)
C(2)-Sn(2)-X
C(9)-Sn(2)-X
C(10)-Sn(2)-X
C(1)-C(2)-Sn(2)
C(3)-C(2)-Sn(2)
Sn(1)-X-Sn(2)
123.6(3)
117.0(3)
119.56(13)
114.5(3)
94.83(4)

5864 Organometallics, Vol. 17, No. 26, 1998
Altmann et al.
The density of the crystals was measured using a Micromer-
itics Accu Pyc 1330. Elemental analyses were performed on a
LECO-CHNS-932 analyzer.
and in 7 by 0.089(4) Å (Sn(1)) and 0.174(4) Å (Sn(2)) in
direction of the terminal chlorine atoms Cl(1) and Cl-
(2), respectively.
NMR Sp ect r oscop y. NMR spectra were recorded on
Bruker DRX400 and Bruker DPX300 FT NMR spectrometers
with broad band decoupling of 119Sn at 149.21 and 111.92 MHz,
respectively, 19F at 282.41 and 376.50 MHz, and 13C at 100.61
MHz, using external and internal deuterium locks. 1H, 13C,
19F, and 119Sn NMR chemical shifts δ are given in ppm and
referenced to external Me4Sn (119Sn), CFCl3 (19F), and Me4Si
In 5 the Sn(1)-Cl(3)-Sn(2) bridge is slightly asym-
metric with Sn(1)-Cl(3) 2.7414(11) Å and Sn(2)-Cl(3)
2.8027(10) Å. Consequently, the Sn(1)-Cl(1) distance
of 2.5267(11) Å is greater than the Sn(2)-Cl(2) distance
of 2.4762(11) Å. A similar asymmetry of a Sn-Cl-Sn
bridge was previously reported for [(Ph2ClSnCH2)2‚Cl]--
[(Ph3P)N]+.3c In contrast to the latter compound, the
C(1), C(2), Sn(1), and Sn(2) atoms in 5 lie within a plane
from which the bridging Cl(3) is displaced by 1.512(2)
Å.
With bond distances of Sn(1)-F(1) 2.139(3) Å and Sn-
(2)-F(1) 2.213 Å for the Sn(1)-F(1)-Sn(2) bridge, 7
shows a greater asymmetry than 5 and the related
compound [(Ph2ClSnCH2)2‚F]-[Et4N]+.3f This can be
explained by the interaction between K(1) and Cl(1)
causing Cl(1)-Sn(1) (2.608(2) Å) to be greater than Sn-
(2)-Cl(2) (2.532(2) Å). In contrast to the related complex
[(Ph2ClSnCH2)2‚F]-[Et4N]+ the C(1), C(2), Sn(1), and
Sn(2) atoms in 7 lie within a plane from which the
bridging F(1) is displaced by only 0.3776(4) Å.
The crystal structure of the neutral complex 10
confirms the conclusion drawn from the low-tempera-
ture 119Sn NMR measurement. The HMPA molecule
acts as a monodentate donor toward the Sn(1) atom
whereas the Cl(1) atom bridges the two tin centers
unsymmetrically (Sn(1)-C(1) 2.6108(13) Å; Sn(2)-Cl-
(1) 2.7831(13) Å). Nevertheless, the asymmetry is
smaller than that for related complexes (Ph2ClSnCH2)2‚
(Me2N)3PO and (Ph2ClSn)2CH2‚(Me2N)3PO and is caused
by the rigid o-benzene spacer.3a,c Both tin atoms are
inequivalent and display distorted trigonal bipyramidal
geometries with the axial positions being occupied by
O(1), Cl(1) for Sn(1) and Cl(1), Cl(2) for Sn(2). The
carbon atoms C(1), C(7), C(8) (for Sn(1)) and C(2), C(9),
C(10) (for Sn(2)) define the equatorial planes. The tin
atoms in 10 are displaced from these planes by 0.023-
(3) Å (for Sn(1) in direction of Cl(1)) and 0.157(3) Å (for
Sn(2) in direction of Cl(2)), respectively. In analogy to
5, the atoms C(1), C(2), Sn(1), and Sn(2) lie within a
plane from which the bridging Cl(1) is displaced by
1.188(3) Å. The Sn(1)-O(1) distance of 2.236(3) Å is
comparable with the Sn-O distance found in (Ph2-
ClSnCH2)2‚(Me2N)3PO.3c
Con clu sion . Linking together organotin compounds
results in new and potent Lewis acids. Ditin compounds
separated by two carbon atoms readily form 1:1 adducts
with a variety of Lewis bases including chloride and
fluoride. The stability of these adducts is apparently
affected not only by the Lewis acidity of the two tin
centers but is also assisted by formation of particularly
stable five-membered chelate rings. These results form
a basis for development of new organotin polydentate
Lewis acids capable of greater selectivity toward Lewis
acids such as halides.
1
(13C, H), respectively. Temperatures were maintained using
a Bruker control system. The complexes for NMR investiga-
tions were generally prepared in situ, and the concentrations
of the organotin halides were typically about 0.1-0.2 M.
Electr osp r a y Ma ss Sp ectr om etr y. Electrospray mass
spectra were obtained with a Platform II single quadrupole
mass spectrometer (Micromass, Altrincham, UK) using an
acetonitrile mobile phase. Acetonitrile solutions (1 mM) of the
compounds were injected directly into the spectrometer via a
Rheodyne injector equipped with a 50 µL loop. A Harvard 22
syringe pump delivered the solutions to the vaporization nozzle
of the electrospray ion source at a flow rate of 10 µL min-1
.
Nitrogen was used as both a drying gas and for nebulization
with flow rates of approximately 200 and 20 mL min-1
respectively. Pressure in the mass analyzer region was usually
about 4 × 10-5. Typically, 10 signal-averaged spectra were
collected.
,
Syn th esis of 1,2-Bis(tr im eth ylsta n n yl)ben zen e, o-C6H4-
(Sn Me3)2 (1). 1,2-Dichlorobenzene (22.6 g, 154 mmol) was
added dropwise at -78 °C to a magnetically stirred solution
of trimethylstannylsodium prepared from hexamethyldistan-
nane (50.4 g, 160 mmol), sodium (7.36 g, 320 mmol), and a
catalytical amount of naphthalene (2.5 g, 20 mmol) in 300 mL
of THF. The mixture was stirred for 2 h at -78 °C, 16 h at
room temperature, and 24 h under reflux. Two-thirds of the
THF was distilled off, and 120 mL of diethyl ether was added.
After hydrolysis and filtration of the reaction mixture, the
organic layer was separated, dried over Na2SO4, and filtered.
The solvent was evaporated and naphthalene was removed
by sublimation in vacuo (5 × 10-3 Torr, 100 °C). Distillation
of the residue in vacuo afforded 42 g (67%) of o-C6H4(SnMe3)2
(1) as colorless liquid, bp 120 °C (5 × 10-3 Torr). 119Sn{1H}
NMR (CH2Cl2): δ -33.2 (3J (119Sn-117Sn) ) 220 Hz, 1J (119Sn-
13
C
) ) 340 Hz). 1H NMR (CDCl3): δ 0.29 (s, 2J (1H- 119/117Sn)
Me
) 53/51 Hz, 18H, CH3), 7.2-7.3 (m, 2H, Ph), 7.4-7.6 (m, 2H,
Ph). 13C{1H} NMR (CDCl3): δ -7.0 (1J (13C-119Sn) ) 340 Hz,
CH3), 127.6 (3J (13C-119Sn) ) 47 Hz, Caryl), 138.8 (2J (13C-119Sn)
) 63 Hz, 3J (13C-119Sn) ) 48 Hz, Caryl), 151.7 (1J (13C-119/117Sn)
2
) 515/494 Hz, J (13C-119Sn) ) 72 Hz, Caryl).
Syn th esis of 1,2-Bis(d im eth ylch lor osta n n yl)ben zen e,
o-C6H4(Sn ClMe2)2 (2). Dimethyltin dichloride (16.46 g, 74.91
mmol) was added at room temperature to 1,2-bis(trimethyl-
stannyl)benzene (1) (15.12 g, 37.45 mmol). The mixture was
magnetically stirred at 60 °C for 4 days, and trimethyltin
chloride formed was removed by sublimation in vacuo (5 ×
10-3 Torr, 100 °C). The residue was dissolved in 50 mL of
dichloromethane and filtered. The solvent was removed in
vacuo, and the residue was refluxed in 500 mL of hexane. After
filtration of the hot mixture, the filtrate was stored at -30 °C
for 1 day. A precipitate formed which was filtered and washed
twice with cold hexane to give 10.4 g (62%) of o-C6H4(SnClMe2)2
(2) as colorless amorphous solid, mp 87-90 °C. 119Sn{1H} NMR
(CH2Cl2): δ 81.4 (3J (119Sn-117Sn) ) 307 Hz). 1H NMR
(CDCl3): δ 0.91 (s, 2J (1H- 119/117Sn) ) 61/59 Hz, 12H, CH3),
7.3-7.5 (m, 2H, Ph), 7.7-7.9 (m, 2H, Ph). 13C{1H} NMR
(CDCl3): δ 1.89 (1J (13C-119/117Sn) ) 408/389 Hz, CH3), 129.4
(3J (13C-119Sn) ) 58 Hz, 4J (13C-119Sn) ) 15 Hz, Caryl), 136.9
(2J (13C-119Sn) ) 73 Hz, 3J (13C-119Sn) ) 63 Hz, Caryl), 150.0
Exp er im en ta l Section
Gen er a l Meth od s. All reactions were carried out under an
atmosphere of dry nitrogen. The solvents were purified by
distillation from appropriate drying agents under nitrogen.
The tetraalkylammmonium fluorides, 18-crown-6, dibenzo-18-
crown-6, (Ph3P)2NCl, HMPA, and tin tetrachloride were com-
mercial products.
2
(1J (13C-119/117Sn) ) 591/564 Hz, J (13C-119Sn) ) 76 Hz, Caryl).
Anal. Calcd for C10H16Cl2Sn2 (444.52): C, 27.0; H, 3.6. Found:
C, 27.9; H, 3.8.

o-Bis(haloorganostannyl)benzenes as Lewis Acids
Organometallics, Vol. 17, No. 26, 1998 5865
Syn th esis of 1,2-Bis(m eth yld ich lor osta n n yl)ben zen e,
o-C6H4(Sn Cl2Me)2 (3). Tin tetrachloride (13.60 g, 52.22 mmol)
was added dropwise at 0 °C to 1,2-bis(trimethylstannyl)-
benzene (1) (10.54 g, 26.11 mmol). The mixture was magneti-
cally stirred at 70 °C for 4 days, and the dimethyltin dichloride
formed was removed by sublimation in vacuo (5 × 10-3 Torr,
100 °C). The residue was dissolved in 50 mL of dichlo-
romethane, and a dark brown solid was filtered off. The solvent
was removed in vacuo, and the light brown residue was
refluxed in 500 mL of hexane. After filtration of the hot
reaction mixture, the solvent was removed and 50 mL of
hexane were added to the residue. This mixture was treated
at 50 °C for 6 h in an ultrasonic bath. The resulting suspension
was stored at -30 °C for 1 day. The precipitate was filtered,
washed twice with cold hexane, and dried in vacuo to yield
5.0 g (40%) of o-(MeCl2Sn)2C6H4 (3) as colorless amorphous
solid, mp 110-112 °C. 119Sn{1H} NMR (CH2Cl2): δ 24.0
(3J (119Sn-117Sn) ) 595 Hz). 1H NMR (CDCl3): δ 1.60 (s, 2J (1H-
119/117Sn) ) 79/76 Hz, 6H, CH3), 7.5-7.7 (m, 2H, Ph), 7.8-8.1
(m, 2H, Ph). 13C{1H} NMR (CDCl3): δ 14.1 (1J (13C-119/117Sn)
) 612/630 Hz, CH3), 130.5 (3J (13C-119Sn) ) 78 Hz, 4J (13C-
119Sn) ) 19 Hz, Caryl), 136.7 (2J (13C-119Sn) ) 98 Hz, 3J (13C-
119Sn) ) 66 Hz, Caryl), 150.7 (1J (13C-119/117Sn) ) 886/847 Hz,
2J (13C-119Sn) ) 94 Hz, Caryl). Anal. Calcd for C8H10Cl4Sn2
(485.36): C, 19.8; H, 2.1. Found: C, 20.0; H, 2.2.
Syn th esis of 1,2-Bis(d im eth ylflu or osta n n yl)ben zen e,
o-C6H4(Sn F Me2)2 (4). A solution of 1,2-bis(dimethylchlo-
rostannyl)benzene (2) (1.00 g, 2.25 mmol) in 20 mL of ether
was added dropwise to a magnetically stirred solution of KF
(523 mg, 9.00 mmol) in 10 mL of water, and the stirring was
continued overnight. The colorless precipitate was filtered and
washed twice with water, ethanol, and ether to give 0.65 g
(70%) of o-C6H4(SnFMe2)2 (4) as a colorless amorphous solid,
mp > 300 °C. Anal. Calcd for C10H16F2Sn2 (411.61): C, 29.2;
H, 3.9. Found: C, 29.4; H, 4.0.
Syn t h esis of Bis(t r ip h en ylp h osp or a n ylid en e)a m m o-
n iu m -1,2-bis(d im eth ylch lor osta n n yl)ben zen e Ch lor id e,
[o-C6H4(Sn ClMe2)2‚Cl]- [(P h 3N)2P ]+ (5). 1,2-Bis(dimethyl-
chlorostannyl)benzene (2) (306 mg, 0.69 mmol) was dissolved
in 10 mL of dichloromethane, and (Ph3P)2NCl (395 mg, 0.69
mmol) was added under magnetic stirring. The solution was
stirred for 1 h and filtered. Hexane was added to the filtrate,
and slow evaporation of the dichloromethane afforded 605 mg
(86%) of [o-C6H4(SnClMe2)2‚Cl]-[(Ph3N)2P]+ (5) as colorless
crystals, mp 197-200 °C. 119Sn{1H} NMR (CH2Cl2): δ -78.3.
1H NMR (CDCl3): δ 0.93 (s, 2J (1H- 119/117Sn) ) 72/69 Hz, 12H,
CH3), 7.1-7.2 (m, 2H, PhSn), 7.3-7.7 (m, 30H, PhN), 8.2-8.3
(m, 2H, PhSn). 13C{1H} NMR (CDCl3): δ 7.7 (1J (13C-119/117Sn)
) 530/506 Hz, CH3), 125.0-132.0 (4 signals with 31P coupling,
PhN), 133.4 (Caryl), 137.6 (2J (13C-119Sn) ) 80 Hz, 3J (13C-119Sn)
) 57 Hz, Caryl), 154.5 (2J (13C-119Sn) ) 85 Hz, Caryl). Fexptl ) 1.466
g/cm3. Anal. Calcd for C46H46Cl3NP2Sn2 (1018.51): C, 54.2; H,
4.6; N, 1.4. Found: C, 54.6; H, 4.6; N, 1.4.
Syn th esis of P ota ssiu m Diben zo-18-cr ow n -6-1,2-bis-
(d im eth ylch lor osta n n yl)ben zen e F lu or id e, [o-C6H4(Sn -
ClMe2)2‚F ]-[K‚C20H 24O6]+ (7). A suspension of 1,2-bis-
(dimethylchlorostannyl)benzene (2) (220 mg, 0.495 mmol),
potassium fluoride (29 mg, 0.495 mmol), and dibenzo-18-
crown-6 (178 mg, 0.495 mmol) in 10 mL of dichloromethane
was magnetically stirred overnight. The clear solution was
filtered, and hexane was added to the filtrate. Slow evaporation
of the dichloromethane afforded 305 mg (72%) of [o-C6H4-
(SnClMe2)2‚F]- [K‚C20H24O6]+ (7) as colorless crystals, mp 136-
140 °C. 1H NMR (CDCl3): δ 0.68 (2J (1H-119Sn) ) 72 Hz, 12H,
CH3), 3.96 (8H, OCH2), 4.11 (8H, OCH2), 6.8-6.9 (4H,
Ph18-crown-6), 6.9-7.0 (4H, Ph18-crown-6), 7.05-7.15 (2H, Ph),
8.3-8.5 (2H, Ph). Fexptl ) 1.637 g/cm3. Anal. Calcd for C30H40O6-
FKCl2Sn2 (863.02): C, 41.8; H, 4.7. Found: C, 40.4; H, 4.6.
Crystal structure determination shows 0.5 molar equiv of
1
dichloromethane in the elemental cell and H NMR (δ ) 5.28
ppm (s, 1H, CH2Cl2) supporting this. Anal. Calcd for C30H40O6-
FKCl2Sn2‚0.5CH2Cl2 (905.49): C, 40.5; H, 4.6.
Syn th esis of Tetr a eth yla m m on iu m -1,2-bis(d im eth yl-
flu or ost a n n yl)b en zen e F lu or id e, [o-C6H 4(Sn F Me2)2‚F ]-
[Et4N]+ (8). A suspension of 1,2-bis(dimethylfluorostannyl)-
benzene (4) (161 mg, 0.391 mmol) and Et4NF‚2H2O (72 mg,
0.391 mmol) in 2 mL of dichloromethane was magnetically
stirred for 3 h. The clear solution was filtered, and evaporation
of the solvent afforded 156 mg (71%) of [o-C6H4(SnFMe2)2‚F]-
[Et4N]+ (8) as a colorless amorphous solid, mp 181-183 °C.
119Sn{1H} NMR (CD2Cl2): δ -138.3 (dd, 1J (119Sn-19FI) ) 1954
Hz, 1J (119Sn-19FII) ) 1187 Hz). 19F{1H} NMR (CD2Cl2):
-126.8 (t, 1J (19FII-119Sn) ) 1172 Hz, 2J (19FII-19FI) ) 84 Hz,
δ
1
2
1F, FII), -155.4 (d, J (19FI-119Sn) ) 1912 Hz, J (19FI-19FII) )
83 Hz, 2F, FI). H NMR (CDCl3): δ 0.42 (s, J (1H-119Sn) ) 73
Hz, 12H, CH3), 1.02 (t, 12H, NCH2CH3), 2.86 (q, 8H, NCH2),
7.1-7.2 (2H, Ph), 7.9-8.1 (2H, Ph). 13C{1H} NMR (CDCl3): δ
1
2
-0.22 (t, J (13C-119Sn) ) 581 Hz, J (13C-19F) ) 19 Hz, CH3),
7.0 (NCH2CH3), 51.9 (NCH2), 126.1 (Caryl), 135.6 (Caryl), 152.0
(Caryl). Anal. Calcd for C18H36NF3Sn2 (560.96): C, 38.5; H, 6.5;
N, 2.5. Found: C, 38.8; H, 6.6; N, 2.4.
1
2
Syn th esis of P ota ssiu m 18-Cr ow n -6-1,2-bis(d im eth -
ylflu or osta n n yl)ben zen e F lu or id e, [o-C6H4(Sn F Me2)2‚F ]--
[K‚C12H24O6]+ (9). A suspension of 1,2-bis(dimethylfluorostan-
nyl)benzene (4) (150 mg, 0.364 mmol), potassium fluoride (21
mg, 0.364 mmol) and 18-crown-6 (96 mg, 0.364 mmol) in 10
mL of dichloromethane was magnetically stirred for 3 h. The
clear solution was filtered, and hexane was added to the
filtrate. Slow evaporation of the dichloromethane afforded 180
mg (67%) of [o-C6H4(SnFMe2)2‚F]-[K‚C12H24O6]+ (9) as a color-
less amorphous solid, mp 206-209 °C. 119Sn{1H} NMR (pyri-
dine-d5): δ -146.6 (dd, 1J (119Sn-19FI) ) 1980 Hz, 1J (119Sn-
19
F ) ) 1218 Hz). 19F{1H} NMR (CDCl3): δ -129.8 (t, 1J (19FII-
II
119Sn) ) 1232 Hz, J (19FII-19FI) ) 84 Hz, 1F, FII), -160.3 (d,
2
1J (19FI-119Sn) ) 1892 Hz, 2J (19FI-19FII) ) 81 Hz, 2F, FI). 1H
NMR (CDCl3): δ 0.43 (s, 2J (1H-119Sn) ) 74 Hz, 12H, CH3),
3.58 (t, 24H, OCH2), 7.2.-7.3 (2H, Ph), 8.0-8.2 (2H, Ph). 13C-
{1H} NMR (CDCl3): δ -0.04 (t, 1J (13C-119Sn) ) 587 Hz,
2J (13C-19F) ) 20 Hz, CH3), 69.7 (OCH2), 127.2 (Caryl), 136.5
(Caryl), 154.3 (Caryl). Anal. Calcd for C22H40O6F3KSn2 (736.05):
C, 36.0; H, 5.5. Found: C, 36.3; H, 5.5.
Syn th esis of Tetr a eth yla m m on iu m -1,2-bis(d im eth yl-
ch lor osta n n yl)ben zen e F lu or id e, [o-C6H4(Sn ClMe2)2‚F ]-
[Et4N]+ (6). 1,2-Bis(dimethylchlorostannyl)benzene (2) (331
mg, 0.74 mmol) was dissolved in 10 mL of dichloromethane
and Et4NF‚2H2O (138 mg, 0.74 mmol) added under magnetic
stirring. The solution was stirred for 2 h and filtered. Hexane
was added to the filtrate, and slow evaporation of the dichlo-
romethane afforded 370 mg (84%) of [o-C6H4(SnClMe2)2‚F]-
[Et4N]+ (6) as an amorphous solid, mp 127-130 °C. 119Sn{1H}
NMR (CH2Cl2): δ -100.7 (d, 1J (119Sn-19F) ) 1107 Hz). 19F-
{1H} NMR (CH2Cl2): δ -137.08 (1J (19F-119Sn) ) 1100 Hz).
1H NMR (CDCl3): δ 0.69 (s, 2J (1H-119Sn) ) 71 Hz, 12H, CH3),
1.18 (t, 12H, NCH2CH3), 3.00 (q, 8H, NCH2), 7.2-7.4 (m, 2H,
Ph), 8.4-8.6 (m, 2H, Ph). 13C{1H} NMR (CDCl3): δ 4.3 (CH3),
7.3 (NCH2CH3), 52.2 (NCH2), 127.7 (3J (13C-119Sn) ) 62 Hz,
Syn th esis of th e HMP A Com p lex of 1,2-Bis(d im eth yl-
ch lor ostan n yl)ben zen e, o-C6H4(Sn ClMe2)2‚(Me2N)3P O (10).
To a solution of HMPA (157 mg, 0.877 mmol) in 3 mL of CH2-
Cl2 was added a solution of 1,2-bis(dimethylchlorostannyl)-
benzene (2) (390 mg, 0.877 mmol) in 3 mL of CH2Cl2. After 2
h of stirring, the solvent was removed in vacuo, and the oily
residue was dissolved in 25 mL of diethyl ether. Slow evapora-
tion of the solvent afforded 440 mg (81%) of o-C6H4(SnClMe2)2‚
(Me2N)3PO (10) as
a crystalline solid, mp 143-147 °C.
119Sn{1H} NMR (-80 °C, CD2Cl2): δ -52.9 (s, 1Sn), -98.9 (d,
2J (119Sn-31P) ) 140 Hz, 1Sn). 31P NMR {1H} (-80 °C, CD2-
Cl2): δ 25.5 (s, 2J (31P-119Sn) ) 135 Hz). 1H NMR (RT, CDCl3)
δ 0.90 (s, 2J (1H-119/117Sn) ) 69/66 Hz, 12H, CH3), 2.56 (d,
C
C
aryl), 137.3 (2J (13C-119Sn) ) 81 Hz, 3J (13C-119Sn) ) 62 Hz,
aryl), 152.5 (Caryl). Anal. Calcd for C18H36NFCl2Sn2 (593.77):
C, 36.4; H, 6.1; N, 2.4. Found: C, 36.8; H, 6.2; N, 2.3.

5866 Organometallics, Vol. 17, No. 26, 1998
Altmann et al.
3J (1H-31P) ) 10 Hz, 18H, NCH3), 7.2-7.4 (2H, Ph), 7.8-8.1
(2H, Ph). 13C{1H} NMR (RT, CDCl3) δ 5.8 (1J (13C-119/117Sn) )
523/500 Hz, CH3), 36.7 (NCH3), 127.7 (3J (13C-119Sn) ) 61 Hz,
4J (13C-119Sn) ) 16 Hz, Caryl), 137.0 (2J (13C-119Sn) ) 83 Hz,
3J (13C-119Sn) ) 56 Hz, Caryl), 153.4 (2J (13C-119Sn) ) 84 Hz,
Analyzing the duplicate reflections there was no indication for
any decay (5 and 10). The structures were solved by direct
methods SHELXS8621a and successive difference Fourier
syntheses. Refinement-applied full-matrix least-squares meth-
ods SHELXL9321b and SHELXL97.21c
The absolute configuration for 10 could not be determined
by refinement of the Flack21d parameter 0.36(2). The correct-
ness of the absolute configuration was deduced from the X-ray
data by comparison of the R-values of this and the inverted
structure.
C
aryl). IR (KBr) νPdO ) 1130. IR (5% CHCl3) νPdO ) 1144 cm-1
.
Fexptl ) 1.677 g/cm3. Anal. Calcd for C16H34Cl2N3OPSn2
(623.71): C, 30.8; H, 5.5; N, 6.7. Found: C, 30.9; H, 5.6; N,
6.8.
R ea ct ion of 1,8-Bis(t r im et h ylst a n n yl)n a p h t h a len e,
C
10H 6-1,8-(Sn Me3)2, w it h Dim et h yld ich lor ost a n n a n e,
The H atoms were placed in geometrically calculated
positions using riding model and refined with common isotropic
temperature factors for different C-H types (Cprimary-H 0.96
Å, Csec -H 0.97 Å Uiso 0.139(5) (5), 0.136(5) (7), 0.162(6) (10)
Å2; Caryl-H 0.93 Å, Uiso 0.075(2) (5), 0.113(7) (7), 0.142(8) (10)
Å2).
Atomic scattering factors for neutral atoms and real and
imaginary dispersion terms were taken from ref 21e. Figures
were created by SHELXTL-Plus.21f Crystallographic data are
given in Table 2. Selected bond lengths [Å] and angles [°] are
listed in Table 3.
Me2Sn Cl2. Dimethyltin dichloride (4.12 g, 18.73 mmol) was
added at room temperature to 1,8-bis(trimethylstannyl)naph-
thalene (4.25 g, 9.37 mmol). The mixture was magnetically
stirred at 60 °C for 1 day. A mixture of dimethyltin dichloride
and trimethyltin chloride (4.22 g; ratio 1:2) was removed by
sublimation in vacuo (5 × 10-3 Torr, 100 °C). The resulting
black residue was recrystallized from THF to give 1.20 g (48%)
of 7,7,14,14-tetramethyldinaphtho[1,8-bc:1′,8′-fg][1,5]distan-
nocine17 as the major product, mp 276-280 °C (lit.17 272-274
°C). 119Sn{1H} NMR (CH2Cl2): δ -62.3. H NMR (CDCl3): δ
1
0.50 (s, J (1H-119/117Sn) ) 53/51 Hz, 12H, CH3), 7.41 (dd, 4H,
2
H-3), 7.75 (d, 4H, H-4), 7.80 (d, 4H, H-2). 13C{1H} NMR
(CDCl3): δ -2.8 (1J (13C-119/117Sn) ) 369/352 Hz, CH3), 124.8
(3J (13C-119Sn) ) 55 Hz, C3), 130.1 (C4), 136.9 (2J (13C-119Sn)
) 33 Hz, C2), 146.6 (C1).
Ack n ow led gm en t. We are grateful to the Deutsche
Forschungsgemeinschaft, the Fonds der Chemischen
Industrie, and the Australian Research Council for
financial support.
Cr ysta llogr a p h y. Crystals of [o-C6H4(SnClMe2)2‚Cl]--
[(Ph3P)3N]+ (5) and [o-C6H4(SnClMe2)2‚F]-[K‚C20H24O6]+ (7)
were grown from a CH2Cl2/hexane solution and of o-C6H4-
(SnClMe2)2‚(Me3N)3PO (10) from a CDCl3 solution by slow
evaporation. Intensity data for the colorless crystals were
collected on a Nonius MACH3 (5) and KappaCCD (7 and 10)
diffractometer with graphite-monochromated Mo KR radiation
at 291 K. Three standard reflections were recorded every 60
min (5), and an anisotropic intensity loss up to 1.9% (5) was
detected during X-ray exposure. The data collections for (5 and
10) covered almost the whole sphere of reciprocal space with
360 frames via ω-rotation (∆/ω ) 1°) at two times 5s (5) and
10s (10) per frame. The crystal-to-detector distance was 2.6
cm (5) and 2.6 cm (10). Crystal decay was monitored by
repeating the initial frames at the end of data collection.
Su p p or tin g In for m a tion Ava ila ble: Tables of all coor-
dinates, anisotropic displacement parameters, and geometric
data for compounds 5, 7, and 10 (21 pages). Ordering informa-
tion is given on any current masthead page.
OM980703D
(21) (a) Sheldrick, G. M. Acta Crystallogr. 1990 A46, 467-473. (b)
Sheldrick, G. M. SHELXL93; University of Go¨ttingen, 1993. (c)
Sheldrick, G. M. SHELXL97; University of Go¨ttingen 1997. (d) Flack,
H. D. Acta Crystallogr. 1983, A39, 876-881. (e) International Tables
for Crystallography; Kluwer Academic Publishers: Dordrecht, The
Netherlands, 1992; Vol. C. (f) Sheldrick, G. M. SHELXTL-Plus, Release
4.1; Siemens Analytical X-ray Instruments, Inc.: Madison, WI, 1991.