Methylene-bridged tri- and tetratin compounds as Lewis acids

Article abstract of DOI:10.1021/om970537u

Syntheses of a series of trinuclear tin compounds, (Ph₂XSnCH₂)₂SnXPh (2, X = Ph; 6, X = F; 8, X = Cl) and (PhCl₂SnCH₂)₂SnCl₂ (10) and tetranuclear tin compounds (Ph₂XSnCH₂-SnXPh)₂CH₂ (3, X = Ph; 7, X = F; 9, X = Cl) are reported, and the crystal structure of [(Ph₂FSnCH₂)₂SnFPh·F]^-[C ₁₂H₂₄O₆·K]⁺ (6b) is described. Variable temperature ¹¹⁹Sn and ¹⁹F NMR studies indicate that the structure observed for the anion in 6b in the solid state is retained in solution. There is no NMR evidence for the formation of 1:2 adducts with fluoride ion, although such species are identified in acetonitrile solutions from electrospray mass spectrometry (ESMS). ¹¹⁹Sn NMR spectral data indicate that reaction of trinuclear tin compound 8 with [(Ph₃P)₂N]⁺Cl^- and HMPA results in formation of the 1:1 complexes [(Ph₂ClSnCH₂)₂SnClPh·Cl] ^-[(Ph₃P)₂N]⁺ (8a) and (Ph₂ClSnCH₂)₂SnClPh·[(CH ₃)₂N]₃PO (8b), respectively. In contrast, ¹⁹F and ¹¹⁹Sn NMR data show that the tetranuclear tin compound 7 reacts with fluoride ion to give a stable 1:2 adduct [(Ph₂FSnCH₂SnFPh)₂CH ₂·2F]^2-2[Bu₄N]⁺ (7b) in solution, being no NMR evidence for formation of a 1:1 adduct. However, ESMS indicates the presence of both 1:1 and 1:2 adducts in acetonitrile solution.

Full text of DOI:10.1021/om970537u

5716
Organometallics 1997, 16, 5716-5723
Meth ylen e-Br id ged Tr i- a n d Tetr a tin Com p ou n d s a s
Lew is Acid 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 J une 25, 1997X
Syntheses of a series of trinuclear tin compounds, (Ph2XSnCH2)2SnXPh (2, X ) Ph; 6, X
) F; 8, X ) Cl) and (PhCl2SnCH2)2SnCl2 (10) and tetranuclear tin compounds (Ph2XSnCH2-
SnXPh)2CH2 (3, X ) Ph; 7, X ) F; 9, X ) Cl) are reported, and the crystal structure of
[(Ph2FSnCH2)2SnFPh‚F]-[C12H24O6‚K]+ (6b) is described. Variable temperature 119Sn and
19F NMR studies indicate that the structure observed for the anion in 6b in the solid state
is retained in solution. There is no NMR evidence for the formation of 1:2 adducts with
fluoride ion, although such species are identified in acetonitrile solutions from electrospray
mass spectrometry (ESMS). 119Sn NMR spectral data indicate that reaction of trinuclear
tin compound 8 with [(Ph3P)2N]+Cl- and HMPA results in formation of the 1:1 complexes
[(Ph2ClSnCH2)2SnClPh‚Cl]-[(Ph3P)2N]+ (8a ) and (Ph2ClSnCH2)2SnClPh‚[(CH3)2N]3PO (8b),
respectively. In contrast, 19F and 119Sn NMR data show that the tetranuclear tin compound
7 reacts with fluoride ion to give a stable 1:2 adduct [(Ph2FSnCH2SnFPh)2CH2‚2F]2-2[Bu4N]+
(7b) in solution, being no NMR evidence for formation of a 1:1 adduct. However, ESMS
indicates the presence of both 1:1 and 1:2 adducts in acetonitrile solution.
In tr od u ction
tetrastannanes (Ph2XSnCH2)2SnXPh (2, X ) Ph; 6, X
) F; 8, X ) Cl), (Ph2XSnCH2SnXPh)2CH2 (3, X ) Ph;
7, X ) F; 9, X ) Cl), and (PhCl2SnCH2)2SnCl2 (10) and
their complexation behavior toward fluoride ions, chlo-
ride ions, and HMPA.
In recent years molecular recognition of anions has
become a very popular topic in host-guest chemistry.1
The complexation chemistry of Lewis acid organotin-
(IV) halides has also been intensively studied.2-7 Reac-
tion of alkyl-bridged di- and polystannanes with Lewis
bases results in formation of the corresponding
adducts.2,5-9 Although the trinuclear tin compound
Resu lts a n d Discu ssion
Syn th etic Asp ects. Ph3SnCH2Br (1) was prepared
according to the method of Seyferth and Andrews10c by
reaction of Ph3SnBr with bromomethylzinc bromide.
Reaction of the Grignard reagent 1a with Ph2SnCl2 or
10a
Me2Sn(CH2SnMe3)2 has been described, there is only
one report10b on the complexation behavior of alkyl-
bridged chains containing three tin atoms and no report
on alkyl-bridged systems containing four tin atoms. We
now report the syntheses of methylene-bridged tri- and
2a
(Ph2FSn)2CH2 afforded the perphenylated methylene-
bridged tri- and tetratin chains (Ph3SnCH2)2SnPh2 (2)
and (Ph3SnCH2SnPh2)2CH2 (3), respectively (eqs 1 and
2). Compounds 2 and 3 were transformed into their iodo
X Abstract published in Advance ACS Abstracts, November 15, 1997.
(1) (a) Pierre, J . L.; Baret, P. Bull. Soc. Chim. Fr. 1983, II-367 and
references cited. (b) Dietrich, B. Pure Appl. Chem. 1993, 65, 1457 and
references cited. (c) Schmidtchen, F. P.; Berger, M. Chem. Rev. 1997,
97, 1609 and references cited.
(2) (a) Dakternieks, D.; J urkschat, K.; Zhu, H.; Tiekink, E. R. T.
Organometallics 1995, 14, 2512 and references cited. (b) Dakternieks,
D.; J urkschat, K.; Zobel, B.; Tiekink, E. R. T. Z. Kristallogr. 1996, 211,
757.
(3) Holecek, J .; Nadvornik, M.; Handlir, K.; Lycka, A. J . Organomet.
Chem. 1983, 241, 177.
(4) (a) Sau, A. C.; Carpino, L. A.; Holmes, R. R. J . Organomet. Chem.
1980, 197, 181. (b) Gingras, M. Tetrahedron Lett. 1991, 32, 7384.
(5) J urkschat, K.; Kuivila, H. G.; Liu, S.; Zubieta, J . A. Organo-
metallics 1989, 8, 2755.
(6) Newcomb, M.; Blanda, M. T. Tetrahedron Lett. 1988, 29, 4261.
(7) J urkschat, K.; Gielen, M. Bull. Soc. Chim. Belg. 1982, 91, 803.
(8) Newcomb, M.; Horner, J . H.; Blanda, M. T.; Squattrito, P. J . J .
Am. Chem. Soc. 1989, 111, 6294.
(9) Karol, T. J .; Hutchinson, J . P.; Hyde, J . R.; Kuivila, H. G.;
Zubieta, J . A. Organometallics 1983, 2, 106.
(10) (a) Mitchell, T. N.; Amamria, A.; Fabisch, B.; Kuivila, H. G.;
Karol, T. J .; Swami, K. J . Organomet. Chem. 1983, 259, 157. (b)
Chaniotakis, N. A.; J urkschat, K.; Ru¨hlemann, A. Anal. Chim. Acta
1993, 282, 345. (c) Seyferth, D.; Andrews, S. B. J . Organomet. Chem.
1971, 30, 151. (d) Suzuki, M.; Son, I.-H.; Noyori, R. Organometallics
1990, 9, 3043.
thf
2Ph SnCH MgBr
+ Ph2SnCl2 -2MgBrCl8
3
2
1a
Ph2Sn(CH2SnPh3)2
(1)
2
thf
2Ph SnCH MgBr
+ (Ph2FSn)2CH2 -2MgBrF8
3
2
1a
(Ph3SnCH2SnPh2)2CH2
(2)
3
derivatives (Ph2ISnCH2)2SnIPh (4) and (Ph2ISnCH2-
SnIPh)2CH2 (5), respectively, by reaction with iodine in
CH2Cl2 solution (eqs 3 and 4). Treatment of 4 and 5 in
diethyl ether with aqueous potassium fluoride yielded
(Ph2FSnCH2)2SnFPh (6) and (Ph2FSnCH2SnFPh)2CH2
(7) as colorless amorphous solids which are almost
insoluble in common organic solvents (eqs 3 and 4).
S0276-7333(97)00537-2 CCC: $14.00 © 1997 American Chemical Society

Methylene-Bridged Tri- and Tetratin Compounds
Organometallics, Vol. 16, No. 26, 1997 5717
CH2Cl2
2 + 3I2 -3PhI 8
couplings to the bridging fluorides Fb are smaller than
the couplings to the terminal fluorides Fa (Chart 1). The
19F NMR spectrum of 6c at -95 °C shows two signals
of equal intensity at -100.9 ppm (Fb) and -181.9 ppm
(Fa) with 119Sn satellites, the magnitudes of which
correspond to the nJ (119Sn-19F) observed in the 119Sn
NMR spectrum (Table 1).
3KF
(Ph ISnCH ) SnIPh
8
2
2 2
-3KI
4
(Ph2FSnCH2)2SnFPh
(3)
(4)
6
CH2Cl2
3 + 4I2 -4PhI 8
4KF
(Ph ISnCH SnIPh) CH
2
8
2
2
2
-4KI
5
The NMR data for 6c are consistent with the reten-
tion in solution of the monoanionic structure [(Ph2-
FSnCH2)2SnFPh‚F]- observed in the solid state for 6b.
The coalescence phenomena observed in the NMR
spectra are consistent with an intra- and/or inter-
molecular exchange process involving tin-fluoride bond
rupture and rotation about the Sn-C bond, making Fa
and Fb equivalent at higher temperature.2a There are
no significant changes after addition of further mole
equivalents of Bu4NF‚3H2O to the solution of 6c, and
consequently we have no NMR evidence for the forma-
tion of higher fluoride adducts.
(Ph2FSnCH2SnFPh)2CH2
7
When 4 and 5 were stirred with silver chloride in
acetonitrile for 14 days, (Ph2ClSnCH2)2SnClPh (8) and
(Ph2ClSnCH2SnClPh)2CH2 (9) were formed, respec-
tively, as colorless solids (eqs 5 and 6). Compounds 8
CH3CN
4 + 3AgCl 14 days8
(Ph ClSnCH ) SnClPh
+ 3AgI (5)
2
2 2
8
CH3CN
The negative-ion ES mass spectrum of a solution of 6
in acetonitrile shows an isotopic cluster pattern centered
at m/z ) 845, which is consistent with self-ionization
to give the monoanion [(Ph2FSnCH2)2SnFPh‚F]-. There
is also a weaker cluster pattern (approximately 10%
relative abundance) centered at m/z ) 787 consistent
with the presence of [6 - Ph + 2F]- and small amounts
of dinuclear tin species [Ph2FSnCH2SnF3Ph]- (m/z )
559) and [Ph2FSnCH2SnF2Ph2]- (m/z ) 617). Interest-
ingly, also present are significant quantities of dianionic
species [6 + 2F]2- (m/z ) 432), [6 - Ph+3F]2- (m/z )
403), and [6 - 2Ph + 4F]2- (m/z ) 374). The positive-
ion ESMS carries very little ion current and contains
weak signals consistent with the presence of [Ph3Sn]+
(m/z ) 351), [Ph3Sn(acetonitrile)]+ (m/z ) 392), and
[(Ph3Sn)2F]+ (m/z ) 719). The observation in the ESMS
of phenyl loss was confirmed in a macroscale experiment
by benzene detection using GC. Addition of up to 3 mol
equiv of Bu4NF‚3H2O brings about no significant changes
in the negative-ion ESMS, whereas in the positive-ion
mode ion-pair species such as [6 + (Bu4N)2F]+ (m/z )
1330), [6 + (Bu4N)3F2]+ (m/z ) 1591), [(6 - F + Ph)-
(Bu4N)2F]+ (m/z ) 1388), and [(6 - F + Ph)(Bu4N)3F2]+
(m/z ) 1533) appear.
Rea ction of Bis[((d ip h en ylflu or osta n n yl)m eth -
yl)p h en ylflu or osta n n yl]m eth a n e (7) w ith F lu or id e
Ion s. Addition of 1 mol equiv of Bu4NF‚3H2O to the
tetranuclear tin compound 7 in CH2Cl2 does not give a
clear solution, and no 119Sn NMR signal was observed
between room temperature and -95 °C. The 19F NMR
spectrum at -95 °C displays broad and unresolved
resonances between -120 and -165 ppm, and there is
no clear NMR evidence for the formation of a mono-
anionic adduct [(Ph2FSnCH2SnFPh)2CH2‚F]-[Bu4N]+,
7a (Chart 2). One hypothesis is that the broad signals
result from an intramolecular exchange of the bridging
and terminal fluorine atoms in the 1:1 adduct, 7a , which
still remains rapid on the NMR time scale, even at low
temperature.
5 + 4AgCl
8
14 days
(Ph2ClSnCH2SnClPh)2CH2
+ 4AgI (6)
9
and 9 are soluble in common organic solvents such as
CH2Cl2, CHCl3, toluene and thf. Reaction of 2 with
HgCl2 afforded (PhCl2SnCH2)2SnCl2 (10) (eq 7). Com-
acetone, 0 °C
(PhCl SnCH ) SnCl
2
2 + 6HgCl2
8
(7)
2
2 2
-6PhHgCl
10
pound 10 is soluble in diethyl ether, acetone, and
acetonitrile.
Reaction of 6 with Et4NF‚2H2O gives the anionic
fluoride adduct [(Ph2FSnCH2)2SnFPh‚F]- as crystalline
[Et4N]+ salt 6a (eq 8), which was of insufficient quality
for X-ray analysis. Better quality crystals of anionic
CH2Cl2
6 + Et4NF‚2H2O -2H O8
2
[(Ph2FSnCH2)2SnFPh‚F]-[Et4N]+
(8)
6a
[(Ph2FSnCH2)2SnFPh‚F]- were obtained as the potas-
sium salt [K‚18-crown-6]+, 6b, from reaction between
6 and equimolar quantities of potassium fluoride and
18-crown-6 (eq 9).
CH2Cl2
6 + KF‚18-crown-6
8
[(Ph2FSnCH2)2SnFPh‚F]-[K‚18-crown-6]+
(9)
6b
Rea ction of Bis((d ip h en ylflu or osta n n yl)m eth yl)-
p h en ylflu or osta n n a n e (6) w ith F lu or id e Ion s. The
trinuclear tin compound 6 is insufficiently soluble for
NMR measurements. However, addition of 1 mol
equivalent of Bu4NF‚3H2O to 6 in CH2Cl2 gives a clear
solution for which no 119Sn NMR signal could be
detected at room temperature. However, after cooling
to -80 °C, a 119Sn NMR spectrum is observed and shows
a triplet of triplets resonance at -62.9 ppm (assigned
to Sn(I)) and a doublet of doublet of doublets resonance
at -158.9 ppm (assigned to Sn(II)) with an integral ratio
of 1:2, consistent with the in situ formation of the 1:1
adduct [(Ph2FSnCH2)2SnFPh‚F]-[Bu4N]+, hereafter re-
ferred to as 6c (Table 1). As previously observed,2a the
Addition of a second mole equivalent of Bu4NF‚3H2O
to 7 in CH2Cl2 results in a clear solution. The 119Sn
NMR spectrum of this solution at -95 °C contains two
equally intense resonances at -96.7 ppm (W1/2 ) 330
Hz, Sn(I), doublet of doublets) and -196.5 ppm (W1/2
)
170 Hz, Sn(II), doublet of doublets) (Table 1). The
signals were too broad to enable observation of 3J (Sn-

5718 Organometallics, Vol. 16, No. 26, 1997
Altmann et al.
Ta ble 1. 119Sn (-80 °C) a n d 19F (-95 °C) NMR Da ta in CD2Cl2 of [(P h 2F Sn CH2)2Sn F P h ‚F ]-[Bu 4N]+ (6c) a n d
[(P h 2F Sn CH2Sn F P h )2CH2‚2F ]2-2[Bu 4N]+ (7b)
119Sn NMR
19F NMR
anion
(
119Sn) [ppm]
-62.9 (tt, Sn(I)
-158.9 (ddd, Sn(II)
nJ (119Snx-19Fy) [Hz]
δ(19Fy) [ppm]
-100.9 (Fb)
nJ (19Fy-119Snx) [Hz]
6c
)
1J (119Sn(I)
-
-
-
-
-
19Fb) ) 1234
19Fa) ) 124
19Fa) ) 2216
19Fb) ) 582
19Fb) ) 116
1J (19Fb-119Sn(I)) ) 1224/1174
1J (19Fb-119Sn(II)) ) 573
3J (119Sn(I)
1J (119Sn(II)
1J (119Sn(II)
3J (119Sn(II)
1J (119Sn(I)
)
-181.9 (Fa)
1J (19Fa-119Sn(II)) ) 2163
7b
-96.7 (dd, Sn(I)
)
-
19Fc) ) 1908
19Fb) ) 1171
19Fa) ) 1978
19Fb) ) 1415
-122.0 (Fb)
-145.6 (Fc)
-151.5 (Fa)
1J (19Fb-119Sn) ) 1171
1J (119Sn(I)
1J (119Sn(II)
1J (119Sn(II)
-
-
-
2J (19Fb-
F ) ) 81
19
a/c
-196.5 (dd, Sn(II)
)
1J (19Fc-119Sn(I)) ) 1826
2J (19Fc-19Fb) ) 76
1J (19Fa-119Sn(II)) ) 1906
2J (19Fa-19Fb) ) 73
Ch a r t 1
Ch a r t 2
may again be a result of residual exchange between
bridging and terminal fluorine atoms. Addition of a
third mole equivalent of fluoride ion to 7 causes no
change to the 119Sn and 19F NMR spectra.
The negative-ion ES mass spectrum of 7 in aceto-
nitrile indicates self-ionization to give [7 + F]- (m/z )
1075). After the addition of 1 mol equiv of fluoride ion,
the ESMS shows an additional isotope cluster (centered
at m/z ) 617) consistent with presence of the ditin
species [Ph2FSnCH2SnFPh2‚F]-. After the addition of
a second mole equivalent of fluoride ion, the ESMS gives
clear evidence for the presence of dianionic species [7
- Ph + 3F]2- (m/z ) 518) and [7 + 2F]2- (m/z ) 547) as
well as for the tritin species (Ph2FSnCH2SnF2-
CH2SnFPh2‚F)- (m/z ) 789) and (Ph2FSnCH2SnFPh-
CH2SnFPh2‚F)- (m/z ) 845).
Rea ction of Bis((d ip h en ylch lor osta n n yl)m eth -
yl)p h en ylch lor osta n n a n e (8), Bis[((d ip h en ylch lo-
r ost a n n yl)m et h yl)p h en ylch lor ost a n n yl]m et h a n e
(9), a n d Bis((p h en yld ich lor ost a n n yl)m et h yl)-
d ich lor osta n n a n e (10) w ith Ch lor id e Ion s. Addi-
tion of chloride ions to solutions of the trinuclear tin
species 8 and 10 or the tetranuclear species 9 causes
changes in the position of the 119Sn NMR chemical shifts
(Figure 1). For 8, both the geminal and terminal tin
atoms reach their maximum low-frequency shifts upon
addition of 1 mol equiv chloride ion, indicating formation
of the monoanionic species 8a (Chart 1).
F) couplings. The corresponding 19F NMR spectrum at
-95 °C displays three equally intense resonances at
-122.0, -145.6, and -151.5 ppm (Table 1). Both the
number of signals and the coupling patterns support the
formation of the 1:2 fluoride adduct [(Ph2FSnCH2-
SnFPh)2CH2‚2F]2-2[Bu4N]+, 7b (Chart 2), whose solu-
tion structure has been postulated on the basis that the
more electronegative fluorides would occupy axial posi-
tions in trigonal-bipyramidal geometries about five-
coordinate tin atoms.10d The rather broad resonances
The negative-ion ESMS of 8 in acetonitrile solution
shows isotopic m/z clusters consistent with the self-
ionization of 8 to give [8 + Cl]- (m/z ) 911) and [8-Ph
+ 2Cl]- (m/z ) 869). After the addition of an equimolar
quantity of chloride ion (as a triphenylbenzylphospho-
nium salt), the main isotopic m/z cluster can be assigned

Methylene-Bridged Tri- and Tetratin Compounds
Organometallics, Vol. 16, No. 26, 1997 5719
2
-50.8 (Snb), and -162.9 (Sna) ppm (d, J (119Sn-31P) )
155 Hz). In addition, there are three equal but very
low intensity signals (7% of the major resonances) at
-80.0, -117.0, and -130.0 ppm for which no assign-
ment is made. The 31P NMR spectrum at room tem-
perature shows a signal at 27.0 ppm with no 119/117Sn
satellites, indicating fast exchange. At -88 °C, the
signal shifts to 25.6 ppm and shows an unresolved
2J (31P-119/117Sn) coupling of 147 Hz.
The formation of 8b (Chart 1) at low temperature is
evidenced by (i) the observation of three equally intense
119Sn resonances with considerable low-frequency shifts
with respect to the signals at 20.5 and 89.1 ppm
observed for 8, (ii) the observation of a 2J (119Sna-31P)
coupling in the low-temperature 119Sn NMR, and (iii)
the observation of two resonances for the methylene
carbons (14.4, 15.9 ppm) and three resonances for the
ipso carbons (143.9, 143.3, 142.5 ppm) of the phenyl
groups in the 13C NMR spectrum at -80 °C. It is
interesting to notice that the structural change in 8b
imposed on Sna upon coordination of HMPA is trans-
mitted via chlorine bridges to Snb and even to Snc.
The 119Sn NMR spectrum of a dichloromethane solu-
tion of 8 to which 2 mol equiv of HMPA have been added
shows no signal at room temperature but two signals
with an integral ratio of 1:2 at -13.9 and -186.7 ppm
(d, 2J (119Sn-31P) ) 143 Hz) at -88 °C. In addition, low-
intensity signals appear at -45.2, -82.6, -147.5, and
-208.7 ppm for which no assignment is made. The 31P
NMR spectrum at -88 °C shows a single resonance at
24.1 ppm (2J (119Sn-31P) ) 148 Hz). Both 119Sn (two
major signals) and 31P NMR are consistent with the
formation of 8c (Chart 1). No change of the 119Sn NMR
is observed upon addition of a third mole equivalent
HMPA, i.e., no (Ph2ClSnCH2)2SnClPh‚3HMPA is formed.
This is also confirmed by the observation of two 31P
NMR resonances at 25.9 and 24.8 ppm (2J (119Sn-31P)
) 153 Hz) with an integral ratio of 1:2 at -88 °C,
representing noncoordinated and coordinated HMPA.
F igu r e 1. Plot of 119Sn chemical shift (ppm) versus molar
ratio of [(Ph3P)2N]+Cl-/tin compound.
to [8 + Cl]-. Further additions of chloride ions bring
about no significant change in the ESMS.
Somewhat surprisingly, the data in Figure 1 indicate
that
9
also forms
a
1:1 adduct [(Ph2ClSnCH2-
SnClPh)2CH2‚Cl]-[(Ph3P)2N]+, 9a (Chart 2), with chlo-
ride ion rather than a 1:2 complex. We attribute this
result to the lower coordinating power of chloride ion
toward tin(IV) in comparison to that of fluoride ion.
Because of the very poor solubility of 10 in CH2Cl2,
the 119Sn NMR measurements of 10 to which chloride
ions have been added (Figure 1) were performed in CD3-
CN. They indicate formation of both 1:1 and 1:2 adducts
in solution.
The 13C NMR data for the 1:1 adduct (δ(CH2) 46.1
ppm, 1J (119Sn-13C) ) 775, 691 Hz; δ(Ci) 147.3 ppm,
1J (119Sn-13Ci) ) 1072 Hz) indicate hexacoordinate tin
atoms with the carbon atoms trans.11,12 The sixth
coordination side is very likely occupied by acetonitrile.
The 13C NMR data for the 1:2 adduct (δ(CH2) 56.1
ppm, 1J (119Sn-13C) ) 861, 765 Hz; δ(Ci) 150.2 ppm,
1J (119Sn-13Ci) ) 1143 Hz) are also in agreement with
hexacoordination. The slight difference in comparison
with the 1:1 adduct is a result of replacement of
acetonitrile by chloride.
The negative-ion ESMS of 10 in acetonitrile solution
contains an m/z cluster as the most abundant species,
consistent with the 1:1 adduct [10 + Cl]- (m/z ) 787).
No additional species are observed after addition of up
to 2 mol equiv of chloride ion.
Rea ction of Bis((d ip h en ylch lor osta n n yl)m eth -
yl)p h en ylch lor osta n n a n e (8) w ith HMP A. HMPA
complexes of bis(halodiphenylstannyl)methane and
-ethane have been reported and showed HMPA to be a
nonbridging donor toward these ditin species.7,13,14
The 119Sn NMR spectrum at room temperature of an
equimolar solution of 8 and HMPA in CH2Cl2 shows an
extremly broad signal at -49.9 ppm, indicative of a fast
exchange process. At -80 °C, the 119Sn NMR spectrum
displays three equally intense resonances at -35.9 (Snc),
The negative-ion ESMS of 8, to which 1 mol equiv of
HMPA has been added, shows the presence of peaks
consistent with the species [8 + Cl]- (m/z ) 911) and [8
- Ph + 2Cl]- (m/z ) 869). The positive-mode ESMS of
the same solution gives spectra consistent with [8 - Cl
+ HMPA]+ (m/z ) 1120) and [8-Cl + 2HMPA]+(m/z )
1199).
All structures shown in this paper are postulated on
the basis that pentacoordinate triorganotin(IV) deriva-
tives exhibit trigonal-bipyramidal configurations with
the electronegative substituents occupying the axial
positions.4,10d,13
Molecu la r St r u ct u r e of [(P h 2F Sn CH 2)2Sn F -
P h ‚F ]-[C12H24O6‚K]+ (6b). The molecular structure of
6b is illustrated in Figure 2 showing the crystal-
lographic numbering scheme. Unit cell data and refine-
ment details are given in Table 2. Selected interatomic
parameters are listed in Table 3. Each of the three tin
atoms exhibit a slightly distorted trigonal bipyramid
with two phenyl and one methylene groups in equatorial
and two fluorines in axial positions. The axial F(1)-
Sn(1)-F(2) and F(1)-Sn(2)-F(1a) angles are 175.7(2)°
and 177.1(2)°, respectively. Sn(1) lies 0.228 Å out of the
C(7), C(21), C(31) trigonal plane in direction of F(2).
There is no deviation of Sn(2) from the C(7), C(7a), C(11)
plane. The asymmetry of the Sn(1)-F(1)-Sn(2) bridge
(11) Lockhart, T. P.; Manders, W. F.; Zuckerman, J . J . J . Am. Chem.
Soc. 1985, 107, 4546.
(12) Howard, W. F.; Crecely, R. W.; Nelson, W. H. Inorg. Chem.
1985, 24, 2204.
(13) Gielen, M.; J urkschat, K.; Meunier-Piret, J .; Van Meerssche,
M Bull. Soc. Chim. Belg. 1984, 93, 379.
(14) J urkschat, K.; Hesselbarth, F.; Dargatz, M.; Lehmann, J .;
Kleinpeter, E.; Tzschach, A. J . Organomet. Chem. 1990, 388, 259.

5720 Organometallics, Vol. 16, No. 26, 1997
Altmann et al.
The anionic [(Ph2FSnCH2)2SnFPh‚F]- units are linked
via F(2)‚‚‚[K‚18-crown-6]+ bridges of 2.767 Å to form an
infinite chain. The bridging capacity of [K‚18-crown-
6]+ 15d-20 as well as [Na‚15-crown-5]+ 21 was previously
observed for related anionic tin and silicon compounds.
Exp er im en ta l Section
Gen er a l Meth od s. All reactions were carried out under a
dry nitrogen atmosphere. The solvents were purified by
distillation under nitrogen from the appropriate drying agents.
The tetraalkylammmonium fluorides, HMPA, PPNCl, and 18-
crown-6 were commercial products. Bromotriphenylstannane,
dichlorodiphenylstannane, and bis(diphenylfluorostannyl)-
methane were synthesized as described in the literature.2a,22,23
The experimental density of the crystals of 6b was measured
using a Micromeritics Accu Pyc 1330.
NMR Sp ectr oscop y. NMR spectra were recorded on
Bruker DRX400, Bruker DPX300, and J EOL GX270 FT NMR
spectrometers with broad-band decoupling of 119Sn at 149.21,
111.92, and 100.75 MHz, respectively, 19F at 254.19 MHz, and
13C at 100.61 MHz, using external and internal deuterium lock,
and referenced against external Me4Sn (119Sn), CFCl3 (19F), and
Me4Si (13C, 1H). Temperatures were maintained using a J EOL
GTV3 control system. The complexes for the NMR investiga-
tions were generally prepared in situ. The fluoride complexes
were prepared by reaction of (Ph2FSnCH2)2SnFPh (6) or (Ph2-
FSnCH2SnFPh)2CH2 (7) with the appropriate mole ratios of
Bu4NF‚3H2O in dichloromethane solution. The HMPA com-
plexes of bis((diphenylchlorostannyl)methyl)phenylchloro-
stannane, (Ph2ClSnCH2)2SnClPh‚n[(CH3)2N]3PO (8b, n ) 1;
8c, n ) 2), were generated in situ by reaction of 1:1,
respectively, 1:2 mol ratios of (Ph2ClSnCH2)2SnClPh (8) and
HMPA in dichloromethane. The concentrations of the stannyl
fluorides were typically about 0.1 M.
F igu r e 2. General view (SHELXTL-PLUS) of 6b showing
30% probability displacement ellipsoids and the atom
numbering. Symmetry transformations used to generate
equivalent atoms: (a) ) -x + 1, y, -z + 1/2; (b) ) -x + 3/2,
3
-y + /2, -z + 1.
Ta ble 2. Cr ysta llogr a p h ic Da ta for Com p ou n d 6b
empirical formula
fw
C44H53F4KO6Sn3
1149.03
temperature
wavelength
cryst syst
space group
unit cell dimens
a ) 28.535(10) Å
b ) 10.212(2) Å
c ) 19.015(6) Å
volume
298(2) K
0.710 69
monoclinic
C2/c
R ) 90°
â ) 120.23(2)°
γ ) 90°
4787(2) Å3
Electr osp r a y Ma ss Sp ectr om etr y. Electrospay mass
spectra were obtained with a Platform II single-quadrupole
mass spectrometer (Micromass, Altrincham, U.K.) 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
Z
4
density (calcd)
density (measd)
abs coeff
F(000)
cryst size
1.594 Mg/m3
1.597(5) Mg/m3
1.698 mm-1
2280
0.54 0.32 0.12 mm
1.6-29.96°
0 < h < 40, -14 < k < 0,
-26 < l < 22
6968
6968 [R(int) ) 0.0000]
full-matrix least-squares on F2
6967/0/267
θ range for data collection
no. of index ranges
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
no. of reflns colld
with flow rates of approximately 200 and 20 mL min-1
respectively. The pressure in the mass analyzer region was
usually about 4 × 10-5. Typically, 10 signal-averaged spectra
were collected.
,
no. of indep reflns
refinement method
data/restraints/parameters
goodness-of-fit on F2
final R indices
1.004
R1 ) 0.0683 (F > 4σ(F));
wR2 ) 0.0871
0.525 and -0.438 e Å-3
Syn th esis of (Br om om eth yl)tr iph en ylstan n an e, P h 3Sn -
CH2Br (1). A solution of Ph3SnBr (95.89 g, 223 mmol) in 150
mL of thf was added dropwise at 40 °C to a solution of
BrZnCH2Br prepared from Zn (58.34 g, 892 mmol), dibro-
momethane (155.21 g, 892 mmol) and cupric acetate monohy-
drate (1.00 g, 5.01 mmol) in 400 mL of thf. The reaction
mixture was stirred overnight at 40 °C, and most of the thf
was distilled off. After addition of 300 mL of hexane and 100
mL of 3% hydrochloric acid, the organic layer was separated
and washed with diluted HCl. The solvent was evaporated,
and the resulting yellow oil was dissolved in 200 mL of ether.
largest diff peak and hole
with Sn(1)-F(1) 2.342(4) and Sn(2)-F(1) 2.154(4) Å is
higher in comparison with the related compound
[(Ph2FSn)2CH2‚F]-[NEt4]+.2a The Sn(1)-F(2) of 2.020-
(4) Å is close to a Sn-F single bond of 1.96 Å.15a-c The
Sn-C bond lengths are as expected and comparable
with the corresponding values found in [(Ph2-
FSn)2CH2‚F]-[NEt4]+.2a The Sn(1)-F(1)-Sn(2)-C(7)
four-membered ring is almost planar; the deviations of
Sn(1), C(7), Sn(2), and F(1) from the plane are -0.052-
(2), 0.059(3), -0.056(2), and 0.050(2) Å, respectively. The
torsion angle between the symmetry-related four-
membered rings amounts to 72.57(16)°.
(16) J ohnson, S. E.; Deiters, J . A.; Day, R. O.; Holmes, R. R. J . Am.
Chem. Soc. 1989, 111, 3250.
(17) J ohnson, S. E.; Payne, J . S.; Day, R. O.; Holmes, J . M.; Holmes,
R. R. Inorg. Chem. 1989, 28, 3190.
(18) J ohnson, S. E.; Day, R. O.; Holmes, R. R. Inorg. Chem. 1989,
28, 3182.
(15) (a) Kolb, U.; Dra¨ger, M.; J ousseaume, B. Organometallics 1991,
10, 2737. (b) Al-J uaid, S.; Dhaher, S. M.; Eaborn, C.; Hitchcock, P. B.;
Smith, J . D. J . Organomet. Chem. 1987, 325, 117. (c) Reuter, H.; Puff,
H. J . Organomet. Chem. 1989, 379, 223. (d) Tamao, K.; Hayashi, T.;
Ito, Y.; Shiro, M. Organometallics 1992, 11, 2099. (e) Tamao, K.;
Hayashi, T.; Ito, Y. J . Am. Chem. Soc. 1990, 112, 2422. (f) Brondani,
D.; Carre`, F. H.; Corriu, R. J . P.; Moreau, J . J . E.; Man, M. W. C.
Angew. Chem. 1996, 108, 349.
(19) Carre´, F. H.; Corriu, R. J . P.; Gue´rin, C.; Henner, B. J . L.; Wong
Chi Man, W. W. C. J . Organomet. Chem. 1988, 347, C1.
(20) J ohnson, S. E.; Knobler, C. B. Organometallics 1994, 13, 4928.
(21) Kildea, J . D.; Hiller, W.; Borgsen, B.; Dehnicke, K. Z. Natur-
forsch. 1989, 44b, 889.
(22) Elegbede, K. A.; McLean, R. A. N. J . Organomet. Chem. 1974,
69, 405.
(23) Gilmann, H.; Gist, L. H. J . Org. Chem. 1957, 22, 368.

Methylene-Bridged Tri- and Tetratin Compounds
Organometallics, Vol. 16, No. 26, 1997 5721
Ta ble 3. Selected Bon d Dista n ces (Å), An gles (d eg), a n d Tor sion An gles (d eg) for 6b
Bond Distances
Sn(1)-F(2)
Sn(1)-C(21)
Sn(1)-C(7)
Sn(1)-C(31)
Sn(1)-F(1)
Sn(2)-C(7)
2.020(4)
2.117(8)
2.119(6)
2.133(8)
2.342(4)
2.110(6)
Sn(2)-C(11)
Sn(2)-F(1)
K(1)-O(2)
K(1)-F(2)
K(1)-O(1)
K(1)-O(3)
2.136(11)
2.154(4)
2.761(6)
2.767(4)
2.773(7)
2.865(6)
Bond Angles
F(2)-Sn(1)-C(21)
F(2)-Sn(1)-C(7)
C(21)-Sn(1)-C(7)
F(2)-Sn(1)-C(31)
C(21)-Sn(1)-C(31)
C(7)-Sn(1)-C(31)
F(2)-Sn(1)-F(1)
C(21)-Sn(1)-F(1)
C(7)-Sn(1)-F(1)
C(31)-Sn(1)-F(1)
94.3(3)
C(7)-Sn(2)-C(7a)
C(7)-Sn(2)-C(11)
C(7)-Sn(2)-F(1a)
C(7)-Sn(2)-F(1)
C(11)-Sn(2)-F(1)
F(1a)-Sn(2)-F(1)
F(2b)-K(1)-F(2)
Sn(2)-F(1)-Sn(1)
Sn(1)-F(2)-K(1)
Sn(2)-C(7)-Sn(1)
113.8(4)
123.1(2)
97.5(2)
99.4(2)
118.8(3)
94.6(3)
114.1(3)
123.7(3)
175.7(2)
88.9(3)
76.5(2)
86.7(2)
80.9(2)
91.45(11)
177.1(2)
180.0
96.70(14)
153.3(2)
105.3(3)
Torsion Angles
C(7)-Sn(2)-F(1)-Sn(1)
C(7a)-Sn(2)-F(1)-Sn(1)
C(11)-Sn(2)-F(1)-Sn(1)
F(1a)-Sn(2)-F(1)-Sn(1)
F(2)-Sn(1)-F(1)-Sn(2)
C(21)-Sn(1)-F(1)-Sn(2)
C(7)-Sn(1)-F(1)-Sn(2)
C(31)-Sn(1)-F(1)-Sn(2)
C(21)-Sn(1)-F(2)-K(1)
C(7)-Sn(1)-F(2)-K(1)
-5.6(2)
107.4(2)
-128.91(11)
51.09(11)
-13(2)
F(1)-Sn(1)-F(2)-K(1)
F(2b)-K(1)-F(2)-Sn(1)
C(7a)-Sn(2)-C(7)-Sn(1)
C(11)-Sn(2)-C(7)-Sn(1)
F(1a)-Sn(2)-C(7)-Sn(1)
F(1)-Sn(2)-C(7)-Sn(1)
F(2)-Sn(1)-C(7)-Sn(2)
C(21)-Sn(1)-C(7)-Sn(2)
C(31)-Sn(1)-C(7)-Sn(2)
F(1)-Sn(1)-C(7)-Sn(2))
74(2)
115(100)
-87.9(3)
92.1(3)
-171.2(3)
125.6(2)
5.7(2)
6.4(3)
172.7(3)
-87.1(4)
70.7(4)
-120.2(2)
-64.9(5)
55.2(5)
-5.9(3)
While stirring, a solution of KF (10.00 g, 172 mmol) in 50 mL
of water was added to convert unreacted Ph3SnBr to insoluble
Ph3SnF. After 3 h, the precipitate was filtered off and the
organic layer was separated and dried over Na2SO4. Addition
of 40 mL of ethanol and slow evaporation of the ether yielded
30 g (30%) of Ph3SnCH2Br as colorless crystals, mp 80-82 °C.
119Sn NMR (CH2Cl2) δ: -129.4 [1J (119Sn-13Ci) 544 Hz]
[1J (119Sn-13CCH2) 368 Hz]. 1H NMR (CDCl3) δ: 3.14 (s, 2H,
CH2) [2J (119Sn-1H) 18 Hz], 7.3-7.6 (m, 15H, Ph3Sn). 13C NMR
(CDCl3, [nJ (119Sn-13C) Hz]) δ: 8.2 (CH2) [370], 128.7 (Cm) [54],
129.4 (Cp) [12], 137.0 (Co) [36], 136.9 (Ci) [542]. Anal. Calcd
for C19H17BrSn (443.94): C, 51.40; H, 3.86. Found: C, 51.71;
H, 3.92.
over Na2SO4, and filtered. Addition of 20 mL of ethanol and
fractional crystallization yielded 1.80 g (28%) of (Ph3SnCH2-
SnPh2)2CH2 as a colorless solid, mp 84-86 °C. 119Sn NMR
(CH2Cl2) δ: -25.9 (gemSn, 2Sn) [2J (119Sn-117Sn) 241 Hz]
[1J (119Sn-13Ci) 492 Hz], -79.8 (terSn, 2Sn) [2J (119Sn-117Sn) 241
Hz] [1J (119Sn-13Ci) 508 Hz]. 1H NMR (CDCl3) δ: 0.19 (s, 2H,
gemSnCH2gemSn) [2J (119Sn-1H) 60 Hz], 0.48 (s, 4H, terSnCH2gemSn)
[2J (119Sn-1H) 62 Hz], 7.0-7.4 (m, 50H, PhSn). 13C NMR
(CDCl3, [nJ (119/117Sn-13C) Hz]) δ: -15.1 (terSnCH2gemSn) [280],
-13.4 (gemSnCH2gemSn) [270], terSnPh: 128.2 (Cm) [51], 128.7
(Cp) [11], 136.8 (Co) [45], 139.4 (Ci) [510/484], gemSnPh: 128.1
(Cm) [51], 128.5 (Cp) [11], 136.5 (Co) [40], 140.9 (Ci) [494/470].
Anal. Calcd for C63H56Sn4 (1287.98): C, 58.75; H, 4.38.
Found: C, 58.65; H, 4.62.
Syn th esis of Bis((tr ip h en ylsta n n yl)m eth yl)d ip h en yl-
sta n n a n e, (P h 3Sn CH2)2Sn P h 2 (2). A solution of Ph2SnCl2
(7.56 g, 22 mmol) in 25 mL of thf was added dropwise to a
magnetically stirred solution of Ph3SnCH2MgBr prepared from
Ph3SnCH2Br (22.25 g, 50 mmol) and Mg (1.30 g, 54 mmol) in
70 mL of thf. The reaction mixture was refluxed overnight,
and two-thirds of the thf was distilled off, followed by addition
of 150 mL of ether. The reaction mixture was hydrolyzed
under ice-cooling with diluted HCl, and the organic layer was
separated, dried over Na2SO4, and filtered. Addition of 40 mL
of ethanol and fractional crystallization yielded 10.80 g (49%)
of (Ph3SnCH2)2SnPh2 as colorless crystals, mp 118-119 °C.
119Sn NMR (CDCl3) δ: -25.0 (gemSn, 1Sn) [2J (119Sn-117Sn) 246
Hz] [1J (119Sn-13Ci) 488 Hz], -79.0 (terSn, 2Sn) [2J (119Sn-117Sn)
244 Hz] [1J (119Sn-13Ci) 509 Hz]. 1H NMR (CDCl3) δ: 0.56 (s,
4H, CH2) [2J (119Sn-1H) 62 Hz], 7.2-7.4 (m, 40H, PhSn). 13C
NMR (CDCl3, [nJ (119/117Sn-13C) Hz]) δ: -14.4 (CH2) [283],
terSnPh: 128.9 (Cm) [50], 129.3 (Cp) [11], 137.4 (Co) [38], 140.0
(Ci) [509/488], gemSnPh: 128.7 (Cm) [48], 129.1 (Cp) [14], 137.1
(Co) [37], 141.3 (Ci). Anal. Calcd for C50H44Sn3 (1001.03): C,
59.99; H, 4.43. Found: C, 60.21; H, 4.42.
Syn th esis of Bis[((tr ip h en ylsta n n yl)m eth yl)d ip h en yl-
stan n yl]m eth an e, (P h 3Sn CH2Sn P h 2)2CH2 (3). (Ph2FSn)2CH2
(2.99 g, 5 mmol) was added in small portions to a magnetically
stirred and filtered solution of Ph3SnCH2MgBr prepared from
Ph3SnCH2Br (4.60 g, 10.3 mmol) and Mg (250 mg, 11.1 mmol)
in 50 mL of thf. The reaction mixture was refluxed overnight.
Two-thirds of the thf was distilled off, and 50 mL of ether was
added. The reaction mixture was hydrolyzed under ice-cooling
with diluted HCl, and the organic layer was separated, dried
Syn th esis of Bis((diph en yflu or ostan n yl)m eth yl)ph en yl-
flu or osta n n a n e, (P h 2F Sn CH2)2Sn F P h (6). Iodine (2.74 g,
10.8 mmol) was added in small portions under ice-cooling to a
magnetically stirred solution of (Ph3SnCH2)2SnPh2 (3.60 g, 3.6
mmol) in 20 mL of dichloromethane. The reaction mixture
was stirred overnight. The solvent and iodobenzene were
removed in vacuo. Addition of 10 mL of dichloromethane,
filtration and evaportion of the solvent afforded 3.80 g (92%)
of (Ph2ISnCH2)2SnIPh (4) as an oil. 119Sn NMR (CH2Cl2) δ:
-12.9 (gemSn, 1Sn) [2J (119Sn-117Sn) 283 Hz] [1J (119Sn-13Ci) 568
Hz], -66.5 (terSn, 2Sn) [2J (119Sn-117Sn) 281 Hz] [1J (119Sn-13Ci)
560 Hz]. 1H NMR (CDCl3) δ: 1.60 (s, 4H, CH2) [2J (119Sn-1H)
61 Hz], 7.0-7.7 (m, 25H, PhSn). 13C NMR (CDCl3, [nJ (119Sn-
13C) Hz]) δ: 0.2 (CH2) [268], terSnPh: 128.8 (Cm) [64], 130.1
(Cp), 135.8 (Co) [52], 137.9 (Ci), gemSnPh: 128.6 (Cm) [64], 129.9
(Cp), 135.4 (Co) [52].
A solution of (Ph2ISnCH2)2SnIPh (3.80 g, 3.30 mmol) in 10
mL of ether was added dropwise to a magnetically stirred
solution of KF (1.72 g, 29.73 mmol) in 15 mL of water, and
stirring was continued overnight. The colorless precipitate
was filtered off and washed twice with water, methanol, and
ether to give 2.32 g (85%) of (Ph2FSnCH2)2SnFPh as a colorless
amorphous solid, mp > 250 °C. Anal. Calcd for C32H29Sn3F3
(826.71): C, 46.49; H, 3.54. Found: C, 45.48; H, 3.58.
Syn th esis of Bis[((d ip h en yflu or osta n n yl)m eth yl)p h en -
ylflu or osta n n yl]m eth a n e, (P h 2F Sn CH2Sn F P h )2CH2 (7).
(Ph3SnCH2SnPh2)2CH2 (600 mg, 0.47 mmol) was dissolved in
10 mL of dichloromethane, and iodine (473 mg, 1.86 mmol)
was added in small portions under ice-cooling and magnetic

5722 Organometallics, Vol. 16, No. 26, 1997
Altmann et al.
stirring. The reaction mixture was stirred overnight. The
solvent and iodobenzene were removed in vacuo. Addition of
10 mL of dichloromethane, filtration, and evaporation of the
solvent afforded 620 mg (89%) of (Ph2ISnCH2SnIPh)2CH2 (5)
as an oil. 119Sn NMR (CH2Cl2) δ: -11.4 (gemSn, 2Sn) [2J (119Sn-
117Sn) 286 Hz], -67.1 (terSn, 2Sn) [2J (119Sn-117Sn) 269 Hz]. 1H
NMR (CDCl3) δ: 1.74 (s, 2H, gemSnCH2gemSn), 1.80 (s, 4H,
terSnCH2gemSn), 7.0-7.7 (m, 30H, PhSn). 13C NMR (CDCl3) δ:
0.2 (terSnCH2gemSn), 1.5 (gemSnCH2gemSn), terSnPh: 128.8 (Cm),
130.1 (Cp), 135.8 (Co), 136.8 (Ci), gemSnPh: 128.7 (Cm), 130.0
(Cp), 135.4 (Co), 137.9 (Ci).
mg in 2 mL of CH3CN) δ: -55.8 (gemSn, 1Sn), -101.3 (terSn,
2Sn). 1H NMR (CD3CN) δ: 2.45 (s, 4H, CH2) [2J (119Sn-1H)
89 Hz], 7.4-8.0 (m, 10H, PhSn). 13C NMR (CD3CN,
[nJ (119/117Sn-13C) Hz]) δ: 34.5 (CH2) [606], terSnPh: 129.6 (Cm)
[101], 131.4 (Cp) [20], 135.3 (Co) [67], 143.0 (Ci). Anal. Calcd
for C14H14Cl6Sn3 (751.05): C, 22.39; H, 1.88. Found: C, 22.53;
H, 2.01.
Syn th esis of P ota ssiu m -18-cr ow n -6-bis((d ip h en ylflu o-
r ostan n yl)m eth yl)ph en yldiflu or ostan n ate, [(P h 2FSn CH2)2-
Sn FP h ‚F]-[C12H24O6‚K]+ (6b). A suspension of (Ph2FSnCH2)2-
SnFPh (817 mg, 0.988 mmol), KF (58 mg, 0.988 mmol), and
18-crown-6 (261 mg, 0.988 mmol) in 20 mL of dichloromethane
was refluxed under magnetic stirring. After 2 days, the
solution became almost clear and was filtered. Hexane was
added to the filtrate, and slow evaporation of the dichlo-
romethane yielded 650 mg (57%) of 6b as colorless crystals,
mp 186-187 °C. 119Sn NMR (-80 °C, CD2Cl2) δ: -61.1 (tt,
gemSn, 1Sn) [1J (119Sn-19Fb) 1234 Hz] [3J (119Sn-19Fa) 129 Hz],
-159.5 (ddd, terSn, 2Sn) [1J (119Sn-19Fa) 2216 Hz] [1J (119Sn-
19Fb) 592 Hz] [3J (119Sn-19F) 110 Hz]. 1H NMR (CDCl3) δ: 1.58
(s, 4H, SnCH2Sn) [2J (119Sn-1H) 75 Hz], 3.46 (s, 24H, OCH2-
CH2O), 7.2-8.0 (m, 25H, PhSn). 13C NMR (CDCl3, [nJ (119Sn-
13C) Hz]) δ: 7.8 (SnCH2Sn) [494], 71.4 (OCH2CH2O), terSnPh:
128.3 (Cm) [67], 130.2 (Cp), 137.9 (Co) [51], 145.5 (Ci) [744],
gemSnPh: 129.3 (Cm) [65], 130.2 (Cp), 137.8 (Co), 144.6 (Ci).
Anal. Calcd for C44H53F4O6K Sn3 (1149.12): C, 45.99; H, 4.65.
Found: C, 45.8; H, 4.9.
A solution of (Ph2ISnCH2SnIPh)2CH2 (600 mg, 0.4 mmol)
in 15 mL of ether was added dropwise to a magnetically stirred
solution of KF (374 mg, 6.46 mmol) in 15 mL of water, and
stirring of the suspension was continued overnight. The
colorless precipitate was filtered off and washed twice with
water, methanol, and ether to give 378 mg (89%) of (Ph2-
FSnCH2SnFPh)2CH2 as a colorless amorphous solid, mp > 250
°C. No satisfactory elemental analysis could be obtained.
Syn th esis of Bis((diph en ylch lor ostan n yl)m eth yl)ph en -
ylch lor osta n n a n e, (P h 2ClSn CH2)2Sn ClP h (8). Under ex-
clusion of light, to a solution of (Ph2ISnCH2)2SnIPh (3.00 g,
2.61 mmol) in 35 mL of acetonitrile, AgCl (2.24 g, 15.65 mmol)
was added and the reaction mixture was stirred for 14 days
until the 119Sn NMR showed complete disappearance of (Ph2-
ISnCH2)2SnIPh. The precipitate of AgI was filtered off, and
the solvent was removed in vacuo. The resulting oil was
dissolved in 30 mL of dichloromethane and filtered. Addition
of 10 mL of hexane and slow evaporation of the dichlo-
romethane afforded 2.10 g (93%) of (Ph2ClSnCH2)2SnClPh as
a colorless solid, mp 102-103 °C. 119Sn NMR (CDCl3) δ: 89.1
Syn th esis of Tetr a eth yla m m on iu m Bis((d ip h en ylflu o-
r ostan n yl)m eth yl)ph en yldiflu or ostan n ate [(P h 2FSn CH2)2-
Sn F P h ‚F ]-[Et4N]+ (6a ). A suspension of (Ph2FSnCH2)2-
SnFPh (1.06 g, 1.28 mmol) and Et4NF‚2H2O (238 mg, 1.28
mmol) in 20 mL of dichloromethane was refluxed for 10 min.
The solution was filtered, and 5 mL of hexane was added. After
evaporation of the dichloromethane, 900 mg (72%) of the
(
gemSn, 1Sn) [2J (119Sn-117Sn) 267 Hz], 20.5 (terSn, 2Sn) [2J (119Sn-
117Sn) 281 Hz]. 1H NMR (CDCl3) δ: 1.39 (s, 4H, CH2)
[2J (119Sn-1H) 63 Hz], 7.2-7.7 (m, 25H, PhSn). 13C NMR
(CDCl3, [nJ (119/117Sn-13C) Hz]) δ: 2.6 (CH2) [321/304],
terSnPh: 129.0 (Cm) [66], 130.4 (Cp) [14], 135.6 (Co) [52], 138.3
(Ci) [623/595], gemSnPh: 128.8 (Cm), 130.2 (Cp), 135.1 (Co), 139.7
(Ci). Anal. Calcd for C32H29 Cl3Sn3 (876.06): C, 43.87; H, 3.34.
Found: C, 43.10; H, 3.50.
1
complex was isolated as a colorless solid, mp 134-137 °C. H
NMR (CDCl3) δ: 0.87 (t, 12H, CH3CH2N), 2.65 (q, 8H, CH3-
CH2N), 1.53 (s, 4H, SnCH2Sn) [2J (119Sn-1H) 77 Hz], 7.1-8.0
(m, 25H, Ph). 13C NMR (CDCl3, [nJ (119Sn-13C) Hz]) δ: 5.7
(CH2) [487], 6.6 (CH3CH2N), 51.4 (CH3CH2N), terSnPh: 127.8
(Cm) [67], 128.7 (Cp), 136.0 (Co) [50], 143.7 (Ci), gemSnPh: 127.7
(Cm) [66], 128.7 (Cp), 135.8 (Co) [52], 142.7 (Ci). Anal. Calcd
for C40H49Sn3F4N1 (975.90): C, 49.23; H, 5.06; N, 1.44.
Found: C, 48.78; H, 5.16; N, 1.31.
Cr ysta llogr a p h y. Crystals of [(Ph2FSnCH2)2SnFPh‚F]--
[C12H24O6‚K]+ were grown from CH2Cl2/hexane solutions by
slow evaporation. Intensity data for the colorless crystal were
collected with ω/2θ scans on an Enraf-Nonius CAD4 diffrac-
tometer with graphite-monochromated Mo KR radiation. The
lattice parameters were determined from a symmetry-con-
strained least-squares fit of the angular settings for 25
reflections with θmax ) 15.0°. Three standard reflections were
recorded every 300 reflections, and an anisotropic intensity
loss up to 2.8% was detected during X-ray exposure. The data
were corrected for Lorentz-polarization decay but not for
absorption effects. The structure was solved by standard
Patterson and difference Fourier methods SHELXTL PLUS24
(Sheldrick, 1987), and refined satisfactorily with space group
C2/c by full-matrix least-squares calculations SHELXL93.25
The H atoms were placed in geometrically calculated positions
and refined with a common isotropic temperature factor for
the different C-H types (Haryl, C-H ) 0.93 Å, Uiso ) 0.081(7)
Å2; Halkyl, C-H ) 0.97 Å; Uiso ) 0.124(10) Å2). Atomic
Syn t h esis of Bis[((d ip h en ylch lor ost a n n yl)m et h yl)-
ph en ylch lor ostan n yl]m eth an e, (P h 2ClSn CH2Sn ClP h )2CH2
(9). Under exclusion of light, to a solution of (Ph2ISnCH2-
SnIPh)2CH2 (600 mg, 0.4 mmol) in 10 mL of acetonitrile, AgCl
(462 mg, 3.22 mmol) was added and the reaction mixture was
stirred for 14 days until the 119Sn NMR showed complete
disappearence of (Ph2ISnCH2SnIPh)2CH2. The precipitate of
AgI was filtered off and the solvent was removed in vacuo.
The resulting oil was dissolved in 30 mL of dichloromethane
and filtered. Addition of 10 mL of hexane and slow evapora-
tion of the dichloromethane afforded 400 mg (83%) of (Ph2-
ClSnCH2SnClPh)2CH2 as a solid, mp 58-63 °C. 119Sn NMR
(CDCl3) δ: 85.0 (gemSn, 2Sn), 17.4 (terSn, 2Sn) [2J (119Sn-117Sn)
234 Hz]. 1H NMR (CD2Cl2) δ: 1.33 (s, 4H, terSnCH2Sngem
)
[2J (119Sn-1H) 62 Hz], 1.47 (s, 2H, gemSnCH2Sngem) [2J (119Sn-
1H) 62 Hz], 7.0-7.8 (m, 30H, PhSn). 13C NMR (CD2Cl2,
[nJ (119/117Sn-13C) Hz]) δ: 3.4
(
terSnCH2Sngem) [321], 5.9
(
gemSnCH2Sngem) [327],terSnPh: 129.4 (Cm), 130.8 (Cp), 136.1
(Co), 138.9 (Ci), gemSnPh: 129.2 (Cm), 130.6 (Cp), 135.6 (Co),
140.4 (Ci). No satisfactory elemental analysis could be ob-
tained.
Syn t h esis of Bis((p h en yld ich lor ost a n n yl)m et h yl)d i-
ch lor osta n n a n e, (P h Cl2Sn CH2)2Sn Cl2 (10). A solution of
HgCl2 (4.07 g, 15 mmol) in 20 mL of acetone was added
dropwise to an ice-cooled and magnetically stirred solution of
(Ph3SnCH2)2SnPh2 (2.50 g, 2.5 mmol) in 25 mL of acetone. The
reaction mixture was stirred overnight at room temperature.
The precipitate of PhHgCl was filtered off, and the solvent was
removed in vacuo. A 30 mL portion of ether was added to the
residue, and the rest of PhHgCl was filtered off. Addition of
10 mL of toluene and evaporation of the ether afforded 1.10 g
(59%) of (PhCl2SnCH2)2SnCl2 as a colorless amorphous solid,
mp 145-147 °C. 119Sn NMR (concentration dependent; 150.13
(24) International Tables for Crystallography; Kluwer Academic
Publishers: Dordrecht, The Netherlands, 1992; Vol. C.
(25) Sheldrick, G. M. SHELXTL-PLUS. Release 3.4 for Nicolet
R3m/ V crystallographic system. An Integrated System for Solving,
Refining and Displaying Crystal Structures from Diffraction Data;
Nicolet Instrument Corp.: Madison, WI, 1987.
(26) Sheldrick, G. M. University of Go¨ttingen, 1993.
(27) Nardelli, M. Comput. Chem. 1983, 7, 95.
(28) Spek, A. L. Acta Crystallogr. 1990, A46, C34.
(29) Le Page, Y. J . Appl. Crystallogr. 1987, 20, 264-69.

Methylene-Bridged Tri- and Tetratin Compounds
Organometallics, Vol. 16, No. 26, 1997 5723
scattering factors for neutral atoms and real and imaginary
dispersion terms were taken from International Tables for
X-ray Crystallography.24 The programs used were SHELXTL
PLUS,25 SHELXL93,26 PARST,27 PLATON,28 and MISSYM.29
Crystallographic data are given in Table 2.
Industrie, and the Gambrinus Foundation of Dortmund
University (D.D.) for financial support.
Su p p or tin g In for m a tion Ava ila ble: Tables of atomic
coordinates, anisotropic displacement parameters, bond lengths
and angles, and torsion angles for 6b (9 pages). Ordering
information is given on any current masthead page.
Ack n ow led gm en t. We are grateful to the Deutsche
Forschungsgemeinschaft, the Fonds der Chemischen
OM970537U