Oligomethylene-Bridged Dinuclear Triorganotin Triflates and Diphenylphosphinates. Ion Pairing in the Solid State and Electrolytic Dissociation in Solution of [Ph2Sn(CH2) nSnPh2X](O3SCF3) (X

Article abstract of DOI:10.1021/om049773c

The condensation of [Ph₂(OH)Sn(CH₂) _nSn(OH)Ph₂] (1-3; n = 1-3) with HO₃SCF ₃ and HO₂PPh₂ provided [Ph ₂Sn(CH₂)_nSnPh₂(OH)](O

Full text of DOI:10.1021/om049773c

6150
Organometallics 2004, 23, 6150-6159
Oligomethylene-Bridged Dinuclear Triorganotin
Triflates and Diphenylphosphinates. Ion Pairing in the
Solid State and Electrolytic Dissociation in Solution of
[Ph2Sn(CH2)nSnPh2X](O3SCF3) (X ) OH, O2PPh2; n ) 1-3)
Jens Beckmann,*,† Dainis Dakternieks, Andrew Duthie, and Cassandra Mitchell
Centre for Chiral and Molecular Technologies, Deakin University, Geelong 3217, Australia
Received March 30, 2004
The condensation of [Ph2(OH)Sn(CH2)nSn(OH)Ph2] (1-3; n ) 1-3) with HO3SCF3 and
HO2PPh2 provided [Ph2Sn(CH2)nSnPh2(OH)](O3SCF3) (4-6; n ) 1-3) and [Ph2(O2PPh2)Sn-
(CH2)nSn(O2PPh2)Ph2] (10-12; n ) 1-3), respectively. The reaction of [Ph2Sn(CH2)n-
SnPh2(OH)](O3SCF3) (4-6; n ) 1-3) with HO2PPh2 and NaO2PPh2 gave rise to the formation
of [Ph2Sn(CH2)nSnPh2(O2PPh2)](O3SCF3) (7-9; n ) 1-3) and [Ph2(OH)Sn(CH2)nSn(O2PPh2)-
Ph2] (13-15; n ) 1-3), respectively. In the solid state, compounds 4-9 comprise ion pairs
of cationic cyclo-[Ph2SnCH2SnPh2(OH)]22+, cyclo-[Ph2Sn(CH2)nSnPh2(OH)]+ (n ) 2, 3), and
cyclo-[Ph2Sn(CH2)nSnPh2(O2PPh2)]+ (n ) 1-3) and triflate anions. In MeCN, the eight-
2+
membered-ring system cyclo-[Ph2SnCH2SnPh2(OH)]2 appears to be in equilibrium with
the four-membered-ring system cyclo-[Ph2SnCH2SnPh2(OH)]+. In contrast, compounds 10-
15 show no ionic character. Compounds 1-15 were characterized by multinuclear NMR
spectroscopy in solution and in the solid state, IR spectroscopy, conductivity measurements,
electrospray mass spectrometry, osmometric molecular weight determinations, and X-ray
crystallography (4, 5, 7, and 12).
Introduction
Sn(H2O)2][C5(CO2Me)5]6 and [Me3Sn(H2O)2][N(SO2Me)2].7
In the late 1960s, Kitching and Kumar Das described a
number of trimethyltin cations [Me3SnL2](BPh4) stabi-
lized by solvents and neutral ligands, such as L )
DMSO, DMF, DMA, Ph3PO, and Ph3AsO.8 More re-
cently, similar complexes were prepared with MeCN
and NH3, e.g. [c-Hex3Sn(MeCN)2](SbF6),9 [t-Bu3Sn-
(MeCN)2](BPh4),10 and [Me3Sn(NH3)2][N(SO2Me)2],11
and fully characterized. Triorganotin cations having
intramolecularly coordinating donor (“built-in”) ligands,
e.g. {[Me2N(CH2)3]2SnPh}X (X ) Br, I, PF6) and [1,5-
(Me2NCH2)2C6H3SnBu2]Br, were also reported.12
Triorganotin cations stabilized by neutral donor sol-
vents and ligands, [R3SnLn]+ (L ) neutral molecule; n
) 1, 2; R ) alkyl, aryl), and free triorganotin cations
(“stannylium cations”) [R3Sn]+ have attracted consider-
able attention in the last 80 years.1,2 In 1923, Kraus
and Callis reported that solutions of Me3SnCl in ethanol
show substantial electric conductivities, attributable to
the electrolytic dissociation of Me3SnCl into [Me3Sn-
(EtOH)2]+ cations and chloride anions.3 In the early
1960s, Tobias provided the first spectroscopic evidence
for the existence of hydrated [R3Sn(H2O)2]+ (R ) alkyl,
aryl) in aqueous media.4 Shortly thereafter, Wada and
Okawara isolated the first hydrated triorganotin cation,
[Me3Sn(H2O)2](BPh4),5 in the solid state; however, it was
not until the 1980s that Davies et al. and Blaschette et
al. reported the first fully characterized analogues, [Bu3-
Somewhat disguised cases of triorganotin cations
stabilized by neutral ligands are the di- and trinuclear
species [Et3SnOH(SnEt3)][B(C6F5)4]13 and [Me3SnOH-
(SnMe3)HOSnMe3]X (X ) I, Br),14 which may be re-
(6) (a) Davies, A. G.; Goddard, J. P.; Hursthouse, M. B.; Walker, N.
P. C. J. Chem. Soc., Chem. Commun. 1983, 597. (b) Davies, A. G.;
Goddard, J. P.; Hursthouse, M. B.; Walker, N. P. C. J. Chem. Soc.,
Dalton Trans. 1986, 1873.
* To whom correspondence should be addressed. E-mail: beckmann@
chemie.fu-berlin.de. Fax: ++49-30-838-52440.
† Present address: Institut fu¨r Chemie, Freie Universita¨t Berlin,
Fabeckstrasse 34-36, 14195 Berlin, Germany.
(7) Blaschette, A.; Schomburg, D.; Wieland, E. Z. Anorg. Allg. Chem.
1989, 571, 75.
(1) For a recent review, see: Zharov, I.; Michl, J. Free and complexed
R3M+ cations (M ) Ge, Sn, Pb). In The Chemistry of Organic
Germanium, Tin and Lead Compounds; Rappoport, Z., Ed.; Wiley:
New York, 2002; Vol. 2, Chapter 10, p 633.
(8) (a) Kumar Das, V. G.; Kitching, W. J. Organomet. Chem. 1967,
10, 59. (b) Kitching, W.; Kumar Das, V. G.; Moore, C. J. J. Organomet.
Chem. 1970, 22, 399. (c) Kumar Das, V. G. J. Inorg. Nucl. Chem. 1976,
38, 1241.
(9) Nugent, W. A.; McKinney, R. J.; Harlow, R. L. Organometallics
1984, 3, 1315.
(2) For the preparation and full characterization of the first free
triorganotin cation, [R3Sn][B(C6F5)4] (R ) 2,4,6-triisopropylphenyl),
see: (a) Lambert, J. B.; Lin, L.; Keinan, S.; Mu¨ller, T. J. Am. Chem.
Soc. 2003, 125, 6022. For closely related work, see: (b) Lambert, J.
B.; Zhao, Y.; Wu, H.; Tse, W. C.; Kuhlmann, B. J. Am. Chem. Soc.
1999, 121, 5001. (c) Zharov, I.; King, B. T.; Havlas, Z.; Pardi, A.; Michl,
J. J. Am. Chem. Soc. 2000, 122, 10253. (d) Lambert, J. B.; Lin, L. J.
Org. Chem. 2001, 66, 8537.
(10) Ichinohe, M.; Fukui, H.; Sekiguchi, A. Chem. Lett. 2000, 600.
(11) Blaschette, A.; Hippel, I.; Krahl, J.; Wieland, E.; Jones, P. G.;
Sebald, A. J. Organomet. Chem. 1992, 437, 279.
(12) (a) Jurkschat, K.; Pieper, N.; Seemeyer, S.; Schu¨rmann, M.;
Biesemans, M.; Verbruggen, I.; Willem, R. Organometallics 2001, 20,
868. (b) Ruzicka, A.; Jambor, R.; Cisarova, I.; Holecek, J. Chem. Eur.
J. 2003, 9, 2411 and references therein.
(3) Kraus, C. A.; Callis, C. C. J. Am. Chem. Soc. 1923, 45, 2624.
(4) Tobias, R. S. Organomet. Chem. Rev. 1966, 1, 93 and references
therein.
(13) Lambert, J. B.; Ciro, S. M.; Stern, C. L. J. Organomet. Chem.
1995, 499, 49.
(5) Wada, M.; Okawara, R. J. Organomet. Chem. 1965, 4, 487.
10.1021/om049773c CCC: $27.50 © 2004 American Chemical Society
Publication on Web 11/23/2004

Triorganotin Triflates and Diphenylphosphinates
Organometallics, Vol. 23, No. 26, 2004 6151
garded as the complexes [R3SnLn]+ with one (n ) 1) or
two (n ) 2) neutral ligands L ) R3SnOH (R ) Me, Et).
We now describe a number of oligomethylene-bridged
dinuclear triorganotin triflates, [Ph2Sn(CH2)nSnPh2X](O3-
SCF3) (X ) OH, O2PPh2; n ) 1-3), which comprise ion
pairs of oligomethylene-bridged dinuclear triorganotin
cations and triflate anions in the solid state that
undergo electrolytic dissociation in MeCN. Also reported
are oligomethylene-bridged dinuclear triorganotin diphe-
nylphosphinates, [Ph2XSn(CH2)nSn(O2PPh2)Ph2] (X )
OH, O2PPh2; n ) 1-3), which show no evidence of ionic
character.
Results and Discussion
The starting materials [Ph2(OH)Sn(CH2)nSn(OH)Ph2]
(1-3; n ) 1-3) were prepared by base hydrolysis of the
corresponding species [Ph2(I)Sn(CH2)nSn(I)Ph2] (n )
1-3), similar to a procedure reported for compound 1
by Gielen and Jurkschat (eq 1).15 Compounds 1-3 were
Figure 1. General view of 4 showing 20% probability
displacement ellipsoids and the atom-numbering scheme
(symmetry operation used to generate equivalent atoms:
(a) 1 - x, 1 - y, -z).
2NaOH
Ph2(I)Sn(CH2)nSn(I)Ph2
8
-2NaI
Ph2(OH)Sn(CH2)nSn(OH)Ph2
(1)
The geometry of the two crystallographically indepen-
dent Sn atoms features distorted trigonal bipyramids
(geometrical goodness ∆∑(θ)16 74.7 for Sn1 and 72.2 for
Sn2), in which three carbon atoms occupy the equatorial
plane and two oxygen atoms are situated in the axial
positions. The distortion of the tin atoms is marked by
two sets of distinctively different Sn-O bond distances
at 2.152(2) and 2.443(2) Å for Sn1 and at 2.138(2) and
2.560(2) Å for Sn2, which originate from the strong
coordination of the hydroxy group and the weak as-
sociation of the triflate group. These differences result
in Pauling bond orders (BOs)17 of 0.61 and 0.24 for Sn1
(∑(BO) 0.85) and 0.64 and 0.16 for Sn2 (Σ(BO) 0.80).
The geometry of the Sn atoms (4 + 1 coordination) lies
on the pathway between a tetrahedron and a trigonal
bipyramid.18 It is worthwhile comparing the different
Sn-O bond lengths and Pauling bond orders of 4 with
those of some reference compounds, namely the poly-
meric Ph3SnOH having pentacoordinated Sn atoms
(Sn-O, 2.197(5)/2.255(5) Å; BO, 0.52/0.44, ∑(BO), 0.96),19
the monomeric Mes3SnOH having tetracoordinated Sn
atoms (Sn-O, 1.999(6) Å; BO, 1.00),20 and the mono-
meric [(Me3Si)2CH]3SnO3SCF3 (2.139(4) Å; BO, 0.64).21
Thus, it appears that the coordination of the hydroxy
groups in 4 resembles that in the polymeric Ph3SnOH.
The fact that the Sn-O bond orders associated with the
coordination of the triflate group in 4 are small and that
the sums of the Sn-O bond orders in 4 and [(Me3-
1-3; n ) 1-3
obtained as amorphous solids that are insoluble in most
solvents at room temperature and condense when
heated.15 Compounds 1-3 show sharp IR bands (KBr)
near 3600 cm-1 15
which are assigned to OH stretching
,
vibrations of hydroxy groups not involved in hydrogen
bonding. The 119Sn MAS NMR spectra of 1-3 reveal
signals at δiso -177.0, -187.3, -194.5, and -205.5 for
1 (integral ratio 37:48:10:5), at -224.0 and -238.7 for
2 (integral ratio 90:10), and at -189.9, -196.1, and
-239.8 for 3 (integral ratio 13:14:73), consistent with
the presence of different oligomers possessing penta-
coordinated tin atoms.
[Ph2Sn(CH2)nSnPh2(OH)](O3SCF3) (4-6; n ) 1-3).
The reaction of [Ph2(OH)Sn(CH2)nSn(OH)Ph2] (1 - 3;
n ) 1-3) with 1 equiv of HO3SCF3 provided the
crystalline, air-stable materials [Ph2Sn(CH2)nSnPh2(OH)]-
(O3SCF3) (4-6; n ) 1-3) in high yields (eq 2). Notably,
HO3SCF3
Ph2(OH)Sn(CH2)nSn(OH)Ph2
8
-H2O
1-3; n ) 1-3
[Ph2Sn(CH2)nSnPh2(OH)](O3SCF3)
(2)
4-6; n ) 1-3
the same reaction with more than 1 equiv of HO3SCF3
led to cleavage of phenyl groups and afforded only ill-
defined products.
21
Si)2CH]3SnO3SCF3 are considerably smaller than 1
The solid-state structures of 4 and 5, established by
X-ray crystallography, are shown in Figures 1 and 2;
crystal data and selected bond parameters are collected
in Tables 1-3. The structure of [Ph2SnCH2SnPh2(OH)]-
(O3SCF3) (4) consists of a central eight-membered ring,
cyclo-[Ph2SnCH2SnPh2(µ-OH)]2, which lies across a
crystallographic center of inversion. The Sn atoms are
additionally coordinated by two bidentate triflate an-
ions, giving rise to a tricyclic arrangement (Figure 1).
may be attributed to the ionic character of these bonds.
Accordingly, the structure of 4 may be interpreted in
(16) Definition: ∆∑(θ) ) ∑(θeq) - ∑(θax); 0° (tetrahedron) e ∆∑(θ)
e 90° (trigonal bipyramid) (a) Kolb, U.; Dra¨ger, M.; Jousseaume, B.
Organometallics 1991, 10, 2737. (b) Kolb, U.; Beuter, M.; Dra¨ger, M.
Inorg. Chem. 1994, 33, 4522.
(17) Definition: log BO ) -c(d - dst) with c ) 1.41 and dst ) 2.00
Å. (a) Pauling L. The Nature of the Chemical Bond, 3rd ed.; Cornell
University Press: Ithaca, NY, 1960; Chapter 7. (b) Zickgraf, A.; Beuter,
M.; Kolb, U.; Dra¨ger, M.; Tozer, R.; Dakternieks, D.; Jurkschat, K.
Inorg. Chim. Acta 1998, 275-276, 203.
(14) (a) Perevalova, E. G.; Reshetova, M. D.; Ostapchuk, P. N.;
Slovokhotov, Y. L.; Struchkov, Y. T.; Spiridonov, F. M.; Kisin, A. V.;
Yukhno, I. G. Metalloorg. Khim. 1990, 3, 100. (b) Pavel, I.; Cervantes-
Lee, F.; Haiduc, I.; Pannell, K. H. Inorg. Chem. Commun. 2001, 4, 530.
(15) Gielen, M.; Jurkschat, K. J. Organomet. Chem. 1984, 273, 303.
(18) Britton, D.; Dunitz, J. D. J. Am. Chem. Soc. 1981, 103, 2971.
(19) Glidewell, C.; Liles, D. C. Acta Crystallogr. 1978, B34, 129.
(20) Reuter, H.; Puff, H. J. Organomet. Chem. 1989, 379, 223.
(21) Westerhausen, M.; Schwarz, W. Main Group Met. Chem. 1997,
20, 351.

6152 Organometallics, Vol. 23, No. 26, 2004
Beckmann et al.
Figure 2. General view of 5 showing 20% probability displacement ellipsoids and the atom-numbering scheme (symmetry
operation used to generate equivalent atoms: (a) 0.5 + x, 0.5 - y, 0.5 + z).
Table 1. Crystal Data and Structure Refinement Details for 4, 5, 7, and 12
4
5
7
12
formula
formula wt
cryst syst
cryst size, mm
space group
a, Å
C
26H23F3O4SSn2
C
27H25F3O4SSn2
C
38H32F3O5PSSn2
C
51H46O4P2Sn2
725.88
739.91
926.05
1022.20
monoclinic
0.10 × 0.10 × 0.14
P21/c
monoclinic
0.15 × 0.30 × 0.40
P21/n
11.3508(7)
14.2659(8)
17.8781(10)
90
monoclinic
0.10 × 0.10 × 0.35
P21/n
10.7603(5)
19.7598(9)
13.2294(6)
90
monoclinic
0.30 × 0.40 × 0.40
P21/c
12.2152(7)
20.2426(11)
16.6242(9)
90
9.7842(6)
16.3885(11)
28.9285(18)
90
96.1990(10)
90
b, Å
c, Å
R, deg
â, deg
107.8260(10)
90
94.8060(10)
90
110.7180(10)
90
γ, deg
V, Å3
2756.0(3)
4
2803.0(2)
4
3844.8(4)
4
4611.5(5)
4
Z
F
calcd, Mg m-3
1.749
1.753
1.600
1.472
T, K
293(2)
293(2)
293(2)
293(2)
µ, mm-1
F(000)
1.938
1.907
1.450
1.196
1416
1448
1832
2056
θ range, deg
index ranges
1.86-27.52
-14 e h e 14
-18 e k e 8
-22 e l e 23
17 020
1.86-25.00
-13 e h e 13
-25 e k e 25
-16 e l e 17
24 105
1.65-27.52
-15 e h e 14
-26 e k e 25
-15 e l e 21
24 399
1.42-25.00
-11 e h e 11
-19 e k e 17
-31 e l e 34
24 063
no. of rflns collcd
completeness to θmax, %
no. of indep rflns/Rint
no. of rflns obsd with (I>2σ(I))
no. of refined params
GOF (F2)
98.6
99.3
98.7
99.9
6265
6375
8728
8130
5877
5443
7433
6644
330
338
451
532
1.073
1.044
1.068
1.192
R1(F) (I > 2σ(I))
0.029
0.031
0.030
0.063
wR2(F2) (all data)
(∆/σ)max
0.069
0.077
0.073
0.127
0.0014(1)
0.563/-0.427
<0.0001
0.672/-0.274
<0.0001
0.798/-0.256
<0.0001
1.249 (near Sn)/-0.882
largest diff peak/hole, e Å-3
terms of ion pairing between a dicationic eight-mem-
bered ring, cyclo-[Ph2SnCH2SnPh2(µ-OH)]22+, and two
triflate anions. The dication cyclo-[Ph2SnCH2SnPh2(µ-
OH)]22+ may be regarded as a diprotonated form of the
neutral parent ring, cyclo-(Ph2SnCH2SnPh2O)2, whose
presence has been claimed on the basis of 119Sn NMR
spectroscopy for solutions of partially condensed [Ph2-
(OH)SnCH2Sn(OH)Ph2] (1).15 The hydroxy group of 4
is involved in weak hydrogen bonding to a triflate group
of an adjacent molecule (hydrogen bond parameters (Å,
deg): O1-H1, 0.691(28); H1‚‚‚O4b, 2.296(28); O1‚‚‚O4b,
2.915(3); O1-H1‚‚‚O4, 150.0(33); symmetry operation
labeled b is 1.5 - x, - 0.5 + y, 0.5 - z).22 In addition to
the solvent-free modification of [Ph2SnCH2SnPh2(OH)]-
(O3SCF3) (4), a pseudo-polymorph, namely the acetoni-
trile solvate 4‚MeCN, was investigated by X-ray crys-
tallography.23 Unlike the situation in c-Hex3Sn(MeCN)2]-
(SbF6)9 and [t-Bu3Sn(MeCN)2](BPh4),10 the MeCN is not
coordinated to the Sn atoms but associated via hydrogen
bonding to the hydroxy group. This is somewhat sur-
prising, as the triflate anion is generally a rather weak
(22) (a) Jeffrey, G. A. An Introduction to Hydrogen Bonding, Oxford
University Press: New York, 1997. (b) Steiner, T. Angew. Chem., Int.
Ed. 2002, 41, 48.
(23) The structure of 4‚MeCN is presented in the Supporting
Information.

Triorganotin Triflates and Diphenylphosphinates
Organometallics, Vol. 23, No. 26, 2004 6153
Table 2. Selected Bond Parameters (Å, deg) for 4a
Table 4. Selected Solid-State 119Sn and 31P NMR
Parameters of 4-12a
Sn1-O1
2.152(2)
2.136(3)
2.129(3)
2.560(2)
2.123(4)
Sn1-O2
Sn1-C10
Sn2-O1
Sn2-C1
Sn2-C40
2.443(2)
2.139(4)
2.138(2)
2.124(3)
2.117(3)
119Sn
31P
Sn1-C1a
Sn1-C20
Sn2-O3a
Sn2-C30
δiso
integral
ú
η
σ11 σ22
σ33
δiso integral
4
5
6
-83.9
-137.8
48
52
-234 0.80 295 107 -150
-252 0.25 295 232 -114
O1-Sn1-O2
O1-Sn1-C10
O2-Sn1-C1a
O2-Sn1-C20
C1a-Sn1-C20
O1-Sn2-O3a
O1-Sn2-C30
O3a-Sn2-C1
O3a-Sn2-C40
C1-Sn2-C40
Sn1-O1-Sn2
179.48(8)
95.64(10)
86.49(9)
O1-Sn1-C1a
O1-Sn1-C20
O2-Sn1-C10
C1a-Sn1-C10
C10-Sn1-C20
O1-Sn2-C1
O1-Sn2-C40
O3a-Sn2-C30
C1-Sn2-C30
C30-Sn2-C40
Sn1-C1a-Sn2a
93.65(10)
94.1(1)
-120.4
-129.6
55
45
-271 0.40 310 202 -151
-309 0.40 346 222 -179
83.84(9)
86.27(10)
118.04(13)
177.53(8)
96.99(10)
85.58(9)
109.13(11)
130.96(13)
93.73(10)
94.7(1)
85.31(10)
126.40(12)
116.45(13)
123.07(13)
-69.6
-74.3
-77.1
27
31
42
-218 0.95 282 75 -148
-218 0.95 287 80 -144
-205 1.00 282 77 -128
7
8
9
-78.2
52
48
-277 0.40 272 161 -198 32.4
-300 0.45 367 232 -151
100
100
100
-149.4
83.45(10)
114.72(11)
139.74(11)
-82.1
-131.3
54
46
-254 0.75 304 114 -172 32.9
-254 0.60 334 182 -123
-120.4
-138.8
49
51
-273 0.85 373 141 -153 26.1
-233 0.85 354 156 -94
a Symmetry operation used to generate equivalent atoms: (a)
1 - x, 1 - y, -z.
10 -193.1
-219.2
49
51
-359 0.45 453 292 -166 25.1
-390 0.40 492 336 -170 19.6
50
50
Table 3. Selected Bond Parameters (Å, deg) for 5a
11 -204.7
-240.1
54
46
-361 0.55 484 286 -156 25.1
-355 0.45 497 338 -115 19.6
50
50
Sn1-O1
Sn1-C1
Sn1-C20
Sn2-O3a
Sn2-C30
2.130(3)
2.126(3)
2.133(3)
2.428(2)
2.136(3)
Sn1-O2
Sn1-C10
Sn2-O1
Sn2-C2
Sn2-C40
2.517(2)
2.120(3)
2.161(2)
2.135(3)
2.123(3)
12 -215.5
100
-354 0.60 499 286 -139 20.0
100
a δiso (ppm) ) -σiso ) -(σ11 + σ22 + σ33)/3, ú (ppm) ) σ33 - σiso
,
and η ) (σ22 - σ11)/(σ33 - σiso), where σ11, σ22, and σ33 (ppm) are
the principal tensor components of the shielding anisotropy (SA),
sorted as follows: |σ33 - σiso| > |σ11 - σiso| > |σ22 - σiso|.
O1-Sn1-O2
O1-Sn1-C10
O2-Sn1-C1
O2-Sn1-C20
C1-Sn1-C20
O1-Sn2-O3a
O1-Sn2-C30
O3a-Sn2-C2
O3a-Sn2-C40
C2-Sn2-C40
Sn1-O1-Sn2
170.50(8)
97.90(9)
O1-Sn1-C1
O1-Sn1-C20
O2-Sn1-C10
C1-Sn1-C10
C10-Sn1-C20
O1-Sn2-C2
O1-Sn2-C40
O3a-Sn2-C30
C2-Sn2-C30
C30-Sn2-C40
86.97(10)
97.2(1)
83.99(9)
89.13(9)
119Sn NMR spectroscopy provides a very sensitive tool
for the elucidation of relative coordination numbers in
organotin compounds, particularly of free and solvated
triorganotin cations.1,28 Compounds 4-6 were investi-
gated by 119Sn MAS NMR spectroscopy, and the results
are collected in Table 4. For compounds 4 and 5, the
number of signals is consistent with the number of
crystallographically independent Sn sites. For com-
pound 6, three signals are found, which were tentatively
attributed to the presence of more than one crystal form
in the bulk material. The 119Sn MAS NMR chemical
shifts for 4-6 cover a rather wide range, extending from
δiso -69.6 to -137.8, and are essentially in good agree-
ment with the 4 + 1 coordination geometry of the Sn
atoms. For compound 4 the two signals differ consider-
ably (δiso -83.9 and -137.8), which is probably a
reflection of the different CPh-Sn-CPh angles (C10-
Sn1-C20, 130.96(13)°; C30-Sn2-C40, 116.45(13)°) and
the additional intermolecular Sn1‚‚‚O4b contact of
3.625(3) Å (symmetry operation labeled b is 1.5 - x, -
0.5 + y, 0.5 - z), which increases the coordination
number of Sn1 to 4 + 1 + 1. The isotropic chemical shifts
were accompanied by sets of spinning sidebands indica-
tive of large shielding anisotropies (SA), which were
used to perform tensor analyses according to the method
of Herzfeld and Berger (Table 4).29 The magnitudes of
the anisotropies (ú) of 4-6 fall in the relatively narrow
range between 205 and 309 ppm. In contrast, the
asymmetries (η) for 4-6 are between 0.25 and 1.00 and
cover almost the whole defined range. The IR spectra
(KBr) of 4-6 show reasonably sharp signals at 3587,
3564, and 3567 cm-1, which are assigned to OH stretch-
ing vibrations. In view of the established molecular
structures and the presence (4) and absence (5) of
84.93(9)
119.61(12)
118.42(12)
86.14(11)
95.28(10)
87.72(9)
116.00(11)
121.53(12)
120.52(10)
174.89(8)
97.03(10)
90.09(10)
83.76(9)
121.72(10)
118.58(11)
a Symmetry operation used to generate equivalent atoms: (a)
0.5 + x, 0.5 - y, 0.5 + z.
donor toward Sn, as seen in the organotin complexes
[t-Bu2Sn(OH)(H2O)]2(O3SCF3),24[Me2Sn(H2O)2(OPPh3)2]-
(O3SCF3)2,25 and [Ph2P(OSnt-Bu2)2O‚t-Bu2Sn(OH)2](O3-
SCF3),26 respectively. However, in 4‚MeCN the biden-
tate coordination mode of the triflate anion apparently
outweighs the donor strength of MeCN.27 On the basis
of the close similarity with 4, the solid-state structure
of [Ph2Sn(CH2)2SnPh2(OH)](O3SCF3) (5) may be de-
scribed as an alternating sequence of loosely associated
five-membered cationic rings, cyclo-[Ph2Sn(CH2)2SnPh2-
(µ-OH)]+, and bidentate triflate anions (Figure 2), whose
symmetry translation gives rise to the formation of a
coordination polymer (symmetry operation labeled a is
0.5 + x, 0.5 - y, 0.5 + z). The geometry of the two
crystallographically independent Sn atoms is again best
described as 4 + 1 coordination (geometrical goodness
∆∑(θ)16 76.1 for Sn1 and 80.8 for Sn2), in which the
strongly coordinating hydroxy groups and the weakly
associated triflate anions account for the distortion. The
two sets of different axial Sn-O bond distances, at
2.130(3) and 2.517(2) Å for Sn1 and at 2.161(2) and
2.428(2) Å for Sn2, account for the Pauling bond orders17
of 0.65 and 0.19 for Sn1 (∑(BO) 0.84) and 0.59 and 0.25
for Sn2 (∑(BO) 0.84).
(24) Sakamoto, K.; Hamada, Y.; Akashi, H.; Orita, A.; Otera, J.
Organometallics 1999, 18, 3555.
(28) (a) Edlund, U.; Arshadi, M.; Johnels, D. J. Organomet. Chem.
1993, 456, 57. (b) Kira, M.; Oyamada, T.; Sakurai, H. J. Organomet.
Chem. 1994, 471, C4. (c) Arshadi, M.; Johnels, D.; Edlund, U. Chem.
Commun. 1996, 1279.
(29) (a) Herzfeld, J.; Berger, A. E. J. Chem. Phys. 1980, 73, 6021.
(b) Herzfeld, J.; Chen, X. In Encyclopedia of Nuclear Magnetic
Resonance; Wiley: New York, 1996; Vol. 7, p 6021.
(25) Beckmann, J.; Dakternieks, D.; Duthie, A.; Mitchell, C. Dalton
2003, 3258.
(26) Beckmann, J.; Dakternieks, D.; Duthie, A.; Jurkschat, K.;
Mehring, M.; Mitchell, C.; Schu¨rmann, M. Eur. J. Inorg. Chem. 2003,
4356.
(27) Lawrance, G. A. Chem. Rev. 1986, 86, 17.

6154 Organometallics, Vol. 23, No. 26, 2004
Beckmann et al.
Table 5. Selected Bond Parameters (Å, deg) for 7a
Chart 1
Sn1-O1
Sn1-C1
Sn1-C20
Sn2-O4
Sn2-C30
P1-O1
2.155(2)
2.120(2)
2.131(3)
2.425(2)
2.127(3)
1.524(2)
1.796(3)
Sn1-O3a
Sn1-C10
Sn2-O2
Sn2-C1
Sn2-C40
P1-O2
2.497(2)
2.113(2)
2.147(2)
2.120(3)
2.112(3)
1.517(2)
1.795(3)
P1-C50
P1-C60
O1-Sn1-O3a
O1-Sn1-C10
O3a-Sn1-C1
O3a-Sn1-C20
C1-Sn1-C20
O2-Sn2-O4
O2-Sn2-C30
O4-Sn2-C1
O4-Sn2-C40
C1-Sn2-C40
O1-P1-O2
175.82(7)
91.48(8)
O1-Sn1-C1
O1-Sn1-C20
O3a-Sn1-C10
C1-Sn1-C10
C10-Sn1-C20
O2-Sn2-C1
O2-Sn2-C40
O4-Sn2-C30
C1-Sn2-C30
C30-Sn2-C40
O1-P1-C50
O2-P1-C50
C50-P1-C60
Sn1-O1-P1
98.44(9)
92.35(9)
85.66(9)
85.59(8)
86.32(9)
122.68(11)
119.17(10)
98.83(9)
116.59(10)
171.94(7)
90.66(10)
89.23(9)
90.68(9)
85.76(10)
114.68(11)
127.84(12)
111.98(12)
105.94(13)
106.94(14)
129.31(11)
hydrogen bonding, the slight blue shift of 23 cm-1 by
going from 4 to 5 is rather unexpected. Similar blue
shifts have been discussed in the literature under the
keyword of improper hydrogen bonding.22 Compounds
[Ph2Sn(CH2)nSnPh2(OH)](O3SCF3) (4-6; n ) 1-3) are
readily soluble in polar solvents. The 119Sn NMR spectra
(d3-MeCN) of 4-6 (n ) 1-3) give rise to singlets at δ
-116.0, -139.7, and -102.7, respectively. The molar
conductivities (Λ) of 4-6 in MeCN (88, 111, and 113 S
cm2 mol-1, respectively) are consistent with substantial
electrolytic dissociations to form solvated organotin
cations and triflate anions.30 To further determine the
degree of association of cations and ions in solution,
osmometric molecular weight determinations were per-
formed in MeCN, which somewhat contradict the results
of the conductivity measurements. The measured mo-
lecular weights for 4-6 (60 °C, c ) 13.0 mmol L-1
MeCN) of 705, 789, and 774 are in good agreement with
theoretical values (726, 740, 754) expected for complete
ion pairing.
The speciation of the organotin cations associated
with 4-6 was achieved by electrospray mass spectrom-
etry (ESMS),31 which enables the detection of preformed
ions from solution. The spectra of 4-6 (MeCN, cone
voltage 40 V, positive mode) show highly intense mass
clusters at m/z 577.3 (for 4), 591.4 (for 5), and 605.4 (for
6), respectively, which are unambiguously assigned to
the organotin cations [(Ph2Sn)2(CH2)n(OH)]+ (4a-6a; n
) 1-3); proposed structures are shown in Chart 1. Thus,
it appears that the dicationic eight-membered ring cyclo-
[Ph2SnCH2SnPh2(µ-OH)]22+ observed in the solid-state
structure of 4 undergoes a reversible rearrangement in
solution into the monocationic species cyclo-[(Ph2Sn)2-
(CH2)n(OH)]+ (4a). It is noteworthy that small solvent
molecules, such as MeCN and water, often dissociate
from solvate complexes under electrospray conditions.31
[Ph2Sn(CH2)nSnPh2(O2PPh2)](O3SCF3) (7-9; n )
1-3). The reaction of [Ph2Sn(CH2)nSnPh2(OH)](O3SCF3)
(4-6; n ) 1-3) with 1 equiv of HO2PPh2 proceeded with
condensation of water to give good yields of the air-
stable crystalline solids [Ph2Sn(CH2)nSnPh2(O2PPh2)](O3-
SCF3) (7-9; n ) 1-3) as the main products (eq 3). From
85.85(10)
116.57(12)
113.94(12)
106.79(13)
111.09(13)
121.00(13)
128.44(11)
O1-P1-C60
O2-P1-C60
Sn1-C1-Sn2
Sn2-O2-P1
a Symmetry operation used to generate equivalent atoms: (a)
1 - x, 2 - y, 2 - z.
of very poorly soluble byproducts, namely [Ph2(O2PPh2)-
Sn(CH2)nSn(O2PPh2)Ph2] (11, 12; n ) 2, 3), were iso-
lated. A similar observation was made during the
synthesis of cyclo-[Ph2P(OSnMe2O)2PPh2](O3SCF3)2 from
Me2SnO, HO3SCF3, and HO2PPh2, whereby polymeric
Me2Sn(O2PPh2)2 was obtained as the byproduct.32 Com-
pounds 11 and 12 were subsequently prepared from the
more rational, high-yielding syntheses given below.
The crystal structure of [Ph2SnCH2SnPh2(O2PPh2)](O3-
SCF3) (7) is shown in Figure 3. Crystal data and selected
bond parameters are collected in Tables 1 and 5,
respectively. The structure may be described as two
symmetry-related six-membered cationic rings, cyclo-
[Ph2P(OSnPh2)2CH2]+, that are weakly associated with
two related bidentate triflate anions, rendering the Sn
atoms pentacoordinated. It is interesting to note that
these six-membered cationic rings are isoelectronic with
the recently reported metastable stannasiloxane ring,
cyclo-Ph2Si(OSnPh2)2CH2.33 Similar to compounds 4 and
5, the geometry of the two crystallographically inde-
pendent Sn atoms of 7 is distorted trigonal bipyramidal
(geometrical goodness ∆∑(θ)16 76.2 for Sn1 and 78.9 for
Sn2). Once again, the distortion is created by the
different Sn-O bond lengths, this time from the strongly
coordinating diphenylphosphinate group and the weakly
associated triflate group. At 2.155(2) and 2.497(2) Å for
Sn1 and 2.147(2) and 2.425(2) Å for Sn2, these bonds
give rise to Pauling bond orders17 of 0.60 and 0.20 for
Sn1 (∑(BO) 0.80) and 0.62 and 0.25 for Sn2 (∑(BO) 0.87).
The P-O bond lengths of 7 are almost equal at 1.524-
(2) and 1.517(2) Å. 119Sn MAS NMR spectroscopy of 7
- 9 reveals in both cases two signals in the range δiso
-78.2 to -149.4, indicative of two crystallographically
independent Sn sites (Table 4). Interestingly, this range
essentially overlaps with that of compounds 4-6, which
suggests that the relative coordination numbers (4 + 1
HO2PPh2
[Ph2Sn(CH2)nSnPh2(OH)](O3SCF3)
8
-H2O
4-6; n ) 1-3
[Ph2Sn(CH2)nSnPh2(O2PPh2)](O3SCF3)
(3)
(31) (a) Henderson, W.; Taylor, M. J. Polyhedron 1996, 15, 1957.
(b) Dakternieks, D.; Lim, A. E. K.; Lim, K. F. Phosphorus, Sulfur
Silicon Relat. Elem. 1999, 150-151, 339.
7-9; n ) 1-3
(32) Beckmann, J.; Dakternieks, D.; Duthie, A.; Mitchell, C. Orga-
nometallics 2003, 22, 2161.
the crude reaction mixtures of 8 and 9, small amounts
(33) Beckmann, J.; Jurkschat, K.; Rabe, S.; Schu¨rmann, M.; Dak-
ternieks, D.; Duthie, A. Organometallics 2000, 19, 3272.
(30) Geary, W. J. Coord. Chem. Rev. 1971, 7, 81.

Triorganotin Triflates and Diphenylphosphinates
Organometallics, Vol. 23, No. 26, 2004 6155
Figure 3. General view of 7 showing 20% probability displacement ellipsoids and the atom-numbering scheme (symmetry
operation used to generate equivalent atoms: (a) 1 - x, 2 - y, 2 - z).
Chart 2
coordination) are very similar. The magnitude of the
anisotropies (ú) and the asymmetries (η) vary between
232 and 300 ppm and between 0.40 and 0.85, respec-
tively, and hence, the latter of the parameters is less
useful for the characterization of this class of com-
pounds. The 31P MAS NMR spectra of 7-9 show one
signal each at δiso 32.4, 32.9, and 26.1, respectively
(Table 4).
Compounds [Ph2Sn(CH2)nSnPh2(O2PPh2)](O3SCF3) (7-
9; n ) 1-3) are readily soluble in most polar solvents.
The 119Sn NMR spectra (d3-MeCN) of 7-9 (n ) 1-3)
show doublets centered at δ -120.9, -125.7, and
-136.9, with 2J(119Sn-O-31P) couplings of 69, 90, and
120 Hz, respectively. The 31P NMR spectra of the same
samples reveal singlets at δ 34.6, 31.2, and 30.6 with
unresolved 117/119Sn satellites indicating 2J(31P-O-
117/119Sn) couplings of 66, 91, and 119 Hz, respectively.
The observed signals and coupling patterns suggest that
the cyclic core structures of 7-9 are retained in solution,
[Ph2(O2PPh2)Sn(CH2)nSn(O2PPh2)Ph2] (10-12; n
) 1-3). The reaction of [Ph2(OH)Sn(CH2)nSn(OH)Ph2]
(1-3; n ) 1-3) with 2 equiv of HO2PPh2 proceeded
which is in contrast with the dissociative behavior of
under condensation of water to give [Ph2(O2PPh2)Sn-
the recently reported cyclo-[R2Sn(OPPh2O)2SnR2](O3-
(CH2)nSn(O2PPh2)Ph2] (10-12, n ) 1-3) as amorphous
or microcrystalline products in high yields (eq 4). The
SCF3)2 (R ) Me, t-Bu).32 The molar conductivities (Λ)
of 7-9 in MeCN (103, 101, 89 S cm2 mol-1 respectively)
2HO2PPh2
confirm the electrolytic dissociation into solvated
[Ph2(OH)Sn(CH2)nSn(OH)Ph2]
8
organotin cations and triflate anions.30 However, osmo-
metric molecular weight determinations performed on
7 and 8 (60 °C, c ) 10.0 mmol L-1 MeCN) gave
somewhat contradictory results with regard to the
degree of dissociation in MeCN. The molecular weights
of 7 and 8, being 902 and 942, are in excellent agree-
ment with the theoretical values of 926 and 940 for
complete ion pairing.
-2H2O
1-3; n ) 1-3
Ph2(O2PPh2)Sn(CH2)nSn(O2PPh2)Ph2
(4)
10-12; n ) 1-3
solid-state structure of [Ph2(O2PPh2)Sn(CH2)3Sn(O2-
PPh2)Ph2] (12) is shown in Figure 4. Crystal data and
selected bond parameters are collected in Tables 1 and
6, respectively. The structure may be rationalized as a
16-membered macrocycle that lies across a crystal-
lographic center of inversion and therefore contains two
independent Sn and P atoms. In this way it closely
resembles the structure of the tetramer cyclo-[Me3-
SnOPPh2O]4 reported by Haiduc et al.34 Bearing in mind
that the Sn atoms are also linked via propylene bridges,
the overall structure is effectively tricyclic. The two
crystallographically independent Sn atoms feature
Electrospray mass spectrometry was used to identify
the organotin cations associated with 7-9 in solution.31
The ESMS spectra of 7-9 (MeCN, cone voltage 40 V,
positive mode) show highly intense mass clusters at m/z
777.4 (for 7), 791.5 (for 8), and 805.4 (for 9), respectively,
which were unambiguously assigned to the organotin
cations [(Ph2Sn)2(CH2)n(O2PPh2)]+ (7a-9a; n ) 1-3);
proposed structures are shown in Chart 2.

6156 Organometallics, Vol. 23, No. 26, 2004
Beckmann et al.
Figure 4. General view of 12 showing 20% probability displacement ellipsoids and the atom-numbering scheme (symmetry
operation used to generate equivalent atoms: (a) 2 - x, 1 - y, 1 - z).
Table 6. Selected Bond Parameters (Å, deg) for 12a
at 2.205(4) and 2.237(4) Å for Sn1 and 2.215(3) and
2.246(3) Å for Sn2 and account for Pauling bond orders17
Sn1-O1
Sn1-C1
Sn1-C20
Sn2-O4
Sn2-C30
P1-O1
2.237(4)
2.123(6)
2.127(7)
2.215(3)
2.128(6)
1.504(5)
1.794(7)
1.512(5)
1.804(6)
Sn1-O2
Sn1-C10
Sn2-O3
Sn2-C3a
Sn2-C40
P1-O4a
P1-C60
P2-O3
2.205(4)
2.136(6)
2.246(3)
2.132(6)
2.153(6)
1.503(4)
1.783(6)
1.503(4)
1.811(7)
of 0.51 and 0.46 for Sn1 (sum 0.97) and 0.49 and 0.45
for Sn2 (sum 0.92). Compounds 10-12 were also studied
by 119Sn MAS NMR spectroscopy, which shows two
signals for 10 and 11, presumably due to two indepen-
dent Sn sites. Although two independent Sn sites have
been confirmed also by X-ray crystallography for com-
pound 12, 119Sn MAS NMR spectroscopy fails to resolve
the putative magnetic inequivalence. The limited num-
ber of signals suggests that the bulk material of
compounds 10-12 is homogeneous and presumably
consists of only one oligomeric form. In contrast, 119Sn
and 31P MAS NMR spectroscopy of Ph3SnO2PPh2, also
prepared by the condensation of Ph3SnOH with HO2-
PPh2,35 reveals several signals that are indicative of
magnetically inequivalent Sn and P sites, which pre-
sumably arise from the presence of different oligomeric
or crystalline forms.36 The observation that the struc-
tures of 12 and cyclo-[Me3SnOPPh2O]4 have only a small
void within their structures suggests that a 16-mem-
bered ring for Ph3SnO2PPh2 is not feasible on steric
grounds.37 The 119Sn MAS NMR chemical shifts of 10-
12 fall in the narrow range from δiso -193.1 to -240.1
and are consistent with pentacoordinated Sn sites
(Table 4). Interestingly, the magnitudes of the anisotro-
pies (ú) and the asymmetries (η) are also found within
very narrow ranges: between 354 and 390 ppm and
P1-C50
P2-O2
P2-C70
P2-C80
O1-Sn1-O2
O1-Sn1-C10
O2-Sn1-C1
O2-Sn1-C20
C1-Sn1-C20
O3-Sn2-O4
O3-Sn2-C30
O4-Sn2-C3a
O4-Sn2-C40
C3a-Sn2-C40
O1-P1-O4a
O1-P1-C60
O4a-P1-C60
O2-P2-O3
175.18(15)
90.15(20)
90.68(20)
97.26(19)
113.11(24)
176.26(12)
92.74(20)
90.69(21)
89.61(21)
120.35(22)
115.93(26)
107.78(27)
109.81(28)
116.33(24)
108.62(27)
107.59(26)
149.01(26)
152.76(22)
O1-Sn1-C1
O1-Sn1-C20
O2-Sn1-C10
C1-Sn1-C10
C10-Sn1-C20
O3-Sn2-C3a
O3-Sn2-C40
O4-Sn2-C30
C3a-Sn2-C30
C30-Sn2-C40
O1-P1-C50
O4a-P1-C50
C50-P1-C60
O2-P2-C70
O3-P2-C70
C70-P2-C80
Sn1-O2-P2
Sn2-O3-P2
85.69(20)
87.1(2)
89.64(20)
128.75(24)
117.66(24)
85.92(20)
90.74(20)
90.45(20)
123.62(22)
116.03(22)
108.45(28)
107.33(26)
107.21(31)
106.91(26)
110.44(27)
106.54(31)
143.59(26)
143.18(21)
O2-P2-C80
O3-P2-C80
Sn1-O1-P1
Sn2-O4-P1a
a Symmetry operation used to generate equivalent atoms: (a)
2 - x, 1 - y, 1 - z.
slightly distorted trigonal bipyramidal geometries (geo-
metrical goodness ∆∑(θ)16 81.9 for Sn1 and 89.3 for Sn2).
The axial Sn-O bond lengths are only slightly different
(35) Diop, C. A. K.; Lahlou, M.; Diop, L.; Mahieu, B.; Russo, U. Main
Group Met. Chem. 1997, 20, 681.
(34) (a) Newton, M. G.; Haiduc, I.; King, R. B.; Silvestru, C. J. Chem.
Soc., Chem. Commun. 1993, 1229. During the course of this work an
analogue of cyclo-[Me3SnOPPh2O]4, namely cyclo-[Bu3SnOPcycO]4, was
reported: (b) Chandrasekhar, V.; Baskar, V.; Steiner, A.; Zacchini, S.
Organometallics 2004, 23, 1390.
(36) Beckmann, J.; Dakternieks, D.; Duthie, A.; Mitchell, C. Ribot,
F.; d’Espinose de la Caillerie, J. B.; Revel, B. Appl. Organomet. Chem.
2004, 18, 353.
(37) Molloy, K. C.; Nasser, F. A. K.; Barnes, C. L.; Van der Helm,
D.; Zuckerman, J. J. Inorg. Chem. 1982, 21, 960.

Triorganotin Triflates and Diphenylphosphinates
Organometallics, Vol. 23, No. 26, 2004 6157
between 0.40 and 0.60, respectively (Table 4). The 31P
MAS NMR chemical shifts of 10-12 lie between δiso 19.6
and 25.1 (Table 4).
[Ph2(OH)Sn(CH2)nSnPh2(O2PPh2)] (13-15; n )
1-3). The reaction of [Ph2Sn(CH2)nSnPh2(OH)](O3SCF3)
(4-6; n ) 1-3) with 1 equiv of NaO2PPh2 provided [Ph2-
(OH)Sn(CH2)nSn(O2PPh2)Ph2] (13-15, n ) 1-3) as
amorphous solids in high yields (eq 5). Attempts to
Experimental Section
General Considerations. All solvents were distilled prior
to use. HO3SCF3 and HO2PPh2 were purchased from Aldrich,
whereas Ph2(I)Sn(CH)nSn(I)Ph2 (n ) 1-3)15,38 and NaO2PPh2
39
were prepared according to a literature procedure. The solution
NMR spectra were measured using a JEOL Eclipse Plus 400
spectrometer (at 399.78 (1H), 100.54 (13C), 161.84 (31P), and
149.05 MHz (119Sn)) and were referenced against SiMe4,
aqueous H3PO4 (90%), and SnMe4. The solid-state NMR
spectra were measured using the same instrument equipped
with a 6 mm MAS probe. Crystalline NH4H2PO4 (δ 0.95) and
c-Hex4Sn (δ -97.35) were used as secondary references. The
119Sn MAS NMR spectra were obtained using cross polarization
(contact time 5 ms, recycle delay 10 s). The tensor analyses
were performed using the computer program DM Fit 2002.40
The ESMS spectra were obtained with a Platform II single-
quadrupole mass spectrometer (Micromass, Altrincham, U.K.)
using an acetonitrile mobile phase. Acetonitrile solutions (0.1
mM) were injected directly into the spectrometer via a Rheo-
dyne 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 both as 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 mbar. Typically 10 signal-averaged spectra were collected
at a cone voltage of 40 V in the positive detection mode. The
IR spectra were recorded using a BioRad FTIR spectrometer.
Microanalyses were carried out by CMAS, Belmont, Australia.
The thermogravimetric analysis was carried out under air
using a Perkin-Elmer TGA 7 thermogravimetric analyzer with
TAC 7/DX controller and gas selector. The conductivity
measurements were performed using a CDM80 conductivity
meter equipped with a CDC104 conductivity cell (Radiometer,
Copenhagen, Denmark) at 25 °C. Molecular weight determina-
tions were carried out at 60 °C in acetonitrile using a a Gonotec
Osmomat 070 osmometer.
NaO2PPh2
[Ph2Sn(CH2)nSnPh2(OH)](O3SCF3)
8
-NaO3SCF3
4-6; n ) 1-3
[Ph2(OH)Sn(CH2)nSnPh2(O2PPh2)]
(4)
13-15; n ) 1-3
obtain the same materials by the selective condensation
of [Ph2(OH)Sn(CH2)nSn(OH)Ph2] (1-3; n ) 1-3) with
1 equiv of HO2PPh2 failed.
Compounds 13-15 show broad IR bands (KBr) at
3436, 3432, and 3404 cm-1, respectively, which are
assigned to OH stretching vibrations of hydroxy groups
involved in hydrogen bonding. The 119Sn MAS NMR
spectra of 13-15 reveal signals at δiso -189.1, -199.7,
-200.4, and -203.6 for 13 (integral 18:58:18:6), -226.2,
-235.5, -237.0, -239.4, and -263.2 for 14 (integral 19:
28:28:19:6), and approximately -200 for 15 (very broad),
consistent with the presence of magnetically inequiva-
lent Sn sites. The 119Sn MAS NMR chemical shifts of
13-15 fall in the same range as those of [Ph2(OH)Sn-
(CH2)nSn(OH)Ph2] (1-3; n ) 1-3) and [Ph2(O2PPh2)-
Sn(CH2)nSn(O2PPh2)Ph2] (10-12, n ) 1-3). No at-
tempts were made to perform tensor analyses. The 31
P
MAS NMR spectra of 13-15 show signals at δiso 26.6
and 25.3 for 13 (integral 50:50), 22.5 and 13.3 for 14
(integral 40:60), and 22.3 and 18.8 for 15 (integral 35:
65).
In contrast to [Ph2Sn(CH2)nSnPh2X](O3SCF3) (4-9,
X ) OH, O2PPh2; n ) 1-3), the compounds [Ph2XSn-
(CH2)nSn(O2PPh2)Ph2] (10-15, X ) OH, O2PPh2; n )
1-3) possess no noticeable solubility in common organic
solvents at room temperature.
Synthesis of [Ph2(OH)Sn(CH2)nSn(OH)Ph2] (1-3; n )
1-3). A solution of NaOH (796 mg, 20.0 mmol) in water (50
mL) was added to a stirred solution of Ph2(I)Sn(CH)nSn(I)Ph2
(8.14 g for 1 (n ) 1), 8.27 g for 2 (n ) 2), and 8.42 g for 3 (n )
3); 10.0 mmol) in methanol (100 mL), generating a white
precipitate immediately. The reaction mixture was stirred at
room temperature for 1 h. The white precipitate was collected
by filtration, washed with water (150 mL) and methanol (50
mL), and left to dry overnight.
Conclusion
1. Yield: 5.76 g, 97%. Anal. Calcd for C25H23O2Sn2
(593.93): C, 50.64; H, 3.88. Found: C, 50.55; H, 3.79.
2. Yield: 5.17 g, 85%. IR (KBr): ν 3600 s, 3043 s, 3011 s,
2988 w, 2892 m, 2808 m, 1638 w, 1573 w, 1478 m, 1423 s,
1331 w, 1302 m, 1257 m, 1189 m, 1155 w, 1072 s, 1034 s, 997
m, 906 m, 852 w, 814 w, 766 w, 728 s, 697 s, 658 m, 532 m,
502 w, 450 m cm-1. Anal. Calcd for C26H25O2Sn2 (607.86): C,
51.30; H, 4.30. Found: C, 50.90; H, 4.40.
3. Yield: 3.79 g, 61%. IR (KBr): ν 3606 s, 3046 s, 3008 w,
2944 m, 2904 m, 2850 w, 1635 br, 1579 m, 1477 m, 1426 s,
1330 w, 1300 w, 1260 m, 1165 m, 1107 w, 1076 s, 1022 s, 998
m, 922 s, 903 s, 884 m, 725 s, 696 s, 673 m, 659 sh, 643 sh,
516 w, 451 m cm-1. Anal. Calcd for C27H27O2Sn2 (621.99): C,
52.14; H, 4.54. Found: C, 52.10; H, 4.54.
The reaction of [Ph2(OH)Sn(CH2)nSn(OH)Ph2] (1-3,
n ) 1-3) with 1 equiv of the strong acid HO3SCF3
affords [Ph2Sn(CH2)nSnPh2(OH)](O3SCF3) (4-6; n )
1-3), whereas use of larger amounts of HO3SCF3 leads
to phenyl group cleavage and formation of ill-defined
products. On the other hand, the reaction of [Ph2(OH)-
Sn(CH2)nSn(OH)Ph2] (1-3, n ) 1-3) with 2 equiv of the
substantially weaker acid HO2PPh2 produces [Ph2(O2-
PPh2)Sn(CH2)nSn(O2PPh2)Ph2] (10-12, n ) 1-3) with-
out any evidence for the cleavage of phenyl groups.
Apparently, the same reaction with only 1 equiv of HO2-
PPh2 is unselective and fails to provide [Ph2(OH)Sn-
(CH2)nSn(O2PPh2)Ph2] (13-15, n ) 1-3). The reaction
of [Ph2Sn(CH2)nSnPh2(OH)](O3SCF3) (4-6; n ) 1-3)
with HO2PPh2 and NaO2PPh2 gives rise to the formation
of [Ph2Sn(CH2)nSnPh2(O2PPh2)](O3SCF3) (7-9; n )
1-3) and [Ph2(OH)Sn(CH2)nSn(O2PPh2)Ph2] (13-15, n
) 1-3), respectively. Thus, the mildly acidic HO2PPh2
reacts with the basic sites of 4-6, namely the hydroxy
groups, while the conjugate base NaO2PPh2 undergoes
a nucleophilic displacement reaction of the triflate
group.
Synthesis of [Ph2Sn(CH2)nSnPh2(OH)](O3SCF3) (4-6;
n ) 1-3). To a suspension of [Ph2(OH)Sn(CH2)nSn(OH)Ph2]
(2.37 g for 4 (n ) 1), 2.43 g for 5 (n ) 2), and 2.49 g for 6 (n )
(38) (a) Gielen, M.; Jurkschat, K.; Mahieu, B.; Apers, D. J. Orga-
nomet. Chem. 1985, 286, 145. (b) Jurkschat, K.; Hesselbarth, F.;
Dargatz, M.; Lehmann, J.; Kleinpeter, E.; Tzschach, A.; Meunier-Piret,
J. J. Organomet. Chem. 1990, 388, 259.
(39) Horner, L.; Beck, P.; Toscano, V. G. Chem. Ber. 1961, 94, 1317.
(40) Massiot, D.; Fayon, F.; Capron, M.; King, I.; Le Calve´, S.; Alonso,
B.; Durand, J.-O.; Bujoli, B.; Gan, Z.; Hoatson, G. Magn. Reson. Chem.
2002, 40, 70.

6158 Organometallics, Vol. 23, No. 26, 2004
Beckmann et al.
3); 4.0 mmol) in MeCN (20 mL) was added HO3SCF3 (600 mg,
4.0 mmol) via syringe. The mixture was stirred for 15 min to
give a clear solution. Solvent was removed in vacuo, and the
residue was recrystallized from hexane/CH2Cl2 (4 and 5) and
pentane/CH2Cl2 (6).
1H NMR (d3-MeCN): δ 7.8-7.0 (30H), 2.3 (4H). 13C NMR (d3-
MeCN): δ 140.9, 137.0, 136.0, 134.4, 133.4, 131.7, 131.0, 130.9,
129.2, 128.8, 128.5, 128.3, 128.1, 119.4 (CF3), 16.1 (1J(13C-119
-
Sn) ) 561 Hz, J(13C-119Sn) ) 32 Hz). 31P NMR (d3-MeCN):
δ 31.2 (2J(119Sn-O-31P) ) 91 Hz). 119Sn NMR (d3-MeCN): δ
-125.7 (2J(119Sn-O-31P) ) 90 Hz). Conductivity (c ) 3.33
mmol L-1 MeCN): 335 µS. Anal. Calcd for C39H34O5F3PSSn2
(940.20): C, 49.82; H, 3.64. Found: C, 49.89; H, 3.54. Mol wt
(c ) 10.0 mmol L-1 MeCN): 942.
2
4. Yield: 2.64 g, 91%. Mp: 152 °C dec. IR (KBr): ν 3587 s,
3065 m, 3052 m, 3017 w, 2994 w, 2959 w, 2904 w, 1641 br,
1578 m, 1483 m, 1431 s, 1334 w, 1292 s, 1218 s, 1175 s, 1072
m, 1026 s, 994 m, 911 w, 849 w, 803 w, 764 w, 727 s, 695 s,
660 m, 633 s, 586 w, 568 w, 513 w, 489 m, 467 m, 444 m cm-1
.
9. Yield: 1.35 g, 71%. Mp: 216-218 °C. IR (KBr): ν 3065
m, 3051 m, 2950 w, 2912 w, 2858 w, 1481 w, 1458 w, 1432 m,
1383 w, 1334 w, 1299 s, 1277 sh, 1229 s, 1188 m, 1164 w, 1130
s, 1068 m, 1045 m, 1025 s, 997 w, 892 w, 853 w, 730 s, 695 s,
628 m, 577 w, 547 s, 513 w, 449 m cm-1. 1H NMR (d3-MeCN):
δ 7.8-7.0 (30H), 0.8 (4H), 0.7 (2H). 13C NMR (d3-MeCN): δ
142.2, 137.0, 133.1, 131.9, 131.8, 130.9, 129.8, 129.5, 129.3,
119.5 (CF3), 26.9 (1J(13C-119Sn) ) 574 Hz, 3J(13C-119Sn) ) 42
Hz), 22.5 (2J(13C-119Sn) ) 38 Hz). 31P NMR (d3-MeCN): δ 30.6
(2J(119Sn-O-31P) ) 119 Hz). 119Sn NMR (d3-MeCN): δ -136.9
(2J(119Sn-O-31P) ) 120 Hz). Conductivity (c ) 3.33 mmol L-1
MeCN): 298 µS. Anal. Calcd for C40H36O5F3PSSn2 (954.23):
C, 50.35; H, 3.80. Found: C, 50.97; H, 3.86. Mol wt: not
measured due to poor solubility.
Synthesis of [Ph2(O2PPh2)Sn(CH2)nSn(O2PPh2)Ph2] (10-
12; n ) 1-3). [Ph2(OH)Sn(CH2)nSn(OH)Ph2] (1.19 mg for 10
(n ) 1), 1.21 g for 11 (n ) 2), 1.24 g for 12 (n ) 3); 2.00 mmol)
and HO2PPh2 (0.873 g, 4.00 mmol) in MeCN (20 mL) were
stirred at 80 °C for 18 h. The insoluble white precipitate was
isolated by filtration and dried under high vacuum.
10. Yield: 1.59 g, 80%. Mp: 257-259 °C. IR (KBr): ν 3046
m, 3012 w, 2990 w, 2898 w, 2850 w, 1480 w, 1432 m, 1330 w,
1303 w, 1259 w, 1178 sh, 1150 s, 1127 s, 1070 m, 1039 s, 1014
s, 995 m, 972 sh, 922 w, 846 w, 749 m, 727 s, 693 s, 664 m,
648 w, 610 w, 554 s, 544 s, 482 w, 451 m cm-1. Anal. Calcd for
C49H42O4P2Sn2 (994.29): C, 59.19; H, 4.26. Found: C, 59.21;
H, 4.33.
11. Yield: 1.69 g, 84%. Mp: 240-244 °C. IR (KBr): ν 3065
m, 3046 m, 3012 w, 2990 w, 2906 w, 1480 w, 1431 m, 1330 w,
1303 w, 1256 w, 1144 s, 1127 s, 1079 w, 1067 w, 1041 s, 1018
s, 998 m, 919 w, 751 w, 725 s, 693 s, 618 w, 551 s, 537 s, 451
m cm-1. Anal. Calcd for C50H44O4P2Sn2 (1008.32): C, 59.56;
H, 4.40. Found: C, 59.60; H, 4.37.
12. Yield: 1.74 g, 85%. Mp: 216-218 °C. IR (KBr): ν 3053
m, 3014 w, 2989 w, 2961 w, 2944 w, 2894 w, 2850 w, 1480 w,
1432 m, 1331 w, 1300 w, 1260 w, 1179 sh, 1146 s, 1128 s, 1068
m, 1043 s, 1021 s, 998 m, 929 w, 891 w, 848 w, 748 m, 728 s,
694 s, 672 m, 618 w, 551 s, 538 sh, 510 w, 451 m cm-1. Anal.
Calcd for C51H46O4P2Sn2 (1022.34): C, 59.92; H, 4.54. Found:
C, 59.95; H, 4.61.
Synthesis of [Ph2(OH)Sn(CH2)nSnPh2(O2PPh2)] (13-15;
n ) 1-3). [Ph2Sn(CH2)nSnPh2(OH)](O3SCF3) (594 mg for 13
(n ) 1), 608 mg for 14 (n ) 2), 622 mg for 15 (n ) 3); 1.00
mmol) and NaO2PPh2 (0.240 g, 1.00 mmol) were stirred in
MeCN (50 mL) at 80 °C for 18 h. An insoluble white precipitate
was isolated and washed with MeCN to remove any soluble
residue. The solid was dried under high vacuum.
13. Yield: 0.706 g, 89%. Mp: 192-196 °C. IR (KBr): ν 3436
vbr, 3052 m, 3016 w, 2988 w, 2964 w, 2923 w, 2853 w, 1629
br, 1581 w, 1544 w, 1511 w, 1479 w, 1429 w, 1305 w, 1261 w,
1215 w, 1132 s, 1071 w, 1038 s, 1016 m, 997 m, 967 w, 946 w,
909 w, 848 w, 806 w, 752 w, 727 s, 696 s, 660 w, 617 w, 551
m, 537 m, 480 w cm-1. Anal. Calcd for C37H33O3PSn2 (793.72):
C, 55.90; H, 4.10. Found: C, 55.98; H, 4.14. Mol wt: not
measured due to poor solubility.
14. Yield: 0.614 g, 76%. Mp: 188-191 °C. IR (KBr): ν 3432
vbr, 3062 w, 3047 w, 3014 w, 2989 w, 2929 w, 2901 w, 2854
w, 1479 w, 1428 m, 1377 w, 1331 w, 1304 w, 1257 w, 1157 s,
1129 s, 1073 w, 1045 s, 1022 m, 997 w, 923 w, 851 w, 828 w,
811 w, 753 m, 726 s, 694 s, 660 w, 618 w, 547 s, 499 w, 452 m
1H NMR (d3-MeCN): δ 7.3-7.0 (20H), 4.9 (1H), 2.1 (2H). 13C
NMR (d3-MeCN): δ 142.7 (1J(13C-119Sn) ) 740 Hz), 137.3,
131.4, 130.2, 121.9 (CF3), 23.0 (1J(13C-119Sn) ) 459 Hz). 119Sn
NMR (d3-MeCN): δ -116.0. Conductivity (c ) 3.33 mmol L-1
MeCN): 290 µS. Anal. Calcd for C26H23O4F3SSn2 (726.00): C,
43.02; H, 3.19. Found: C, 43.07; H, 3.15. Mol wt (c ) 13.0 mmol
L-1 MeCN): 705.
5. Yield: 2.52 g, 85%. Mp: 143 °C dec. IR (KBr): ν 3564 s,
3064 m, 3048 m, 3020 w, 2992 w, 2944 w, 2904 w, 1635 br,
1578 w, 1481 m, 1427 s, 1404 w, 1300 s, 1262 w, 1215 s, 1182
s, 1072 m, 1029 s, 997 m, 913 w, 886 m, 864 w, 773 sh, 735 s,
694 s, 660 w, 628 s, 574 w, 539 w, 513 w, 507 sh, 447 m, 421
1
m cm-1. H NMR (d3-MeCN): δ 7.6-7.0 (20H), 3.3 (1H), 2.1
(4H). 13C NMR (d3-MeCN): δ 142.9 (1J(13C-119Sn) ) 687 Hz),
137.1, 130.8, 129.7, 121.3 (CF3), 14.6 (1J(13C-119Sn) ) 599 Hz,
2
J(13C-119Sn) ) 30 Hz). 119Sn NMR (d3-MeCN): δ -139.7.
Conductivity (MeCN, c ) 3.33 mmol L-1): 369 µS. Anal. Calcd
for C27H25O4F3SSn2 (740.02): C, 43.82; H, 3.41. Found: C,
43.65; H, 3.34. Mol wt (c ) 13.0 mmol L-1 MeCN): 789.
6. Yield: 2.44 g, 81%. Mp: 149-152 °C dec. IR (KBr): ν
3567 s, 3065 m, 3052 m, 3017 w, 2994 w, 2959 w, 2904 w,
1641 br, 1578 m, 1483 m, 1431 s, 1334 w, 1292 s, 1218 s, 1175
s, 1072 m, 1026 s, 994 m, 911 w, 849 w, 803 w, 764 w, 727 s,
695 s, 660 m, 633 s, 586 w, 568 w, 513 w, 489 m, 467 m, 444
1
m cm-1. H NMR (d3-MeCN): δ 7.5-7.0 (20H), 3.9 (1H), 1.9
(4H), 0.8 (2H). 13C NMR (d3-MeCN): δ 142.5 (1J(13C-119Sn) )
676 Hz), 137.0, 130.7, 129.6, 121.3 (CF3), 23.2 (2J(13C-119Sn)
) 36 Hz), 21.9 (1J(13C-119Sn) ) 554 Hz, 3J(13C-119Sn) ) 14
Hz). 119Sn NMR (d3-MeCN): δ -102.7. Conductivity (c ) 3.33
mmol L-1 MeCN): 377 µS. Anal. Calcd for C28H27O4F3SSn2
(754.05): C, 44.60; H, 3.61. Found: C, 43.75; H, 3.66. Mol wt
(c ) 13.0 mmol L-1 MeCN): 774.
Synthesis of [Ph2Sn(CH2)nSnPh2(O2PPh2)](O3SCF3) (7-
9; n ) 1-3). To a suspension of [Ph2(OH)Sn(CH2)nSn(OH)-
Ph2] (1.19 g for 7 (n ) 1), 1.21 g for 8 (n ) 2), 1.24 g for 9 (n
) 3); 2.0 mmol) in MeCN (20 mL) was added HO3SCF3 (300
mg, 2.00 mmol) via syringe to give a clear solution after 5 min
of stirring at room temperature. Then, HO2PPh2 (0.436 g, 2.00
mmol) was added and the mixture stirred at 80 °C for 1 h.
The solvent was removed in vacuo. The residue was recrystal-
lized from hexane/CH2Cl2. The byproducts of 8 (323 mg, 0.32
mmol; 16%) and 9 (218 mg, 0.21 mmol; 11%) were filtered off
as insoluble solids after 2 days. The solvent was removed in
vacuo and the recrystallization repeated.
7. Yield: 1.04 g, 56%. Mp: 201-205 °C. IR (KBr): ν 3057
s, 1651 m, 1617 w, 1482 m, 1431 s, 1296 m, 1232 s, 1184 m,
1129 s, 1117 s, 1070 m, 1026 s, 1019 s, 995 m, 852 w, 751 sh,
730 s, 695 s, 659 w, 628 m, 605 w, 541 m, 502 w, 447 m, 401
1
w cm-1. H NMR (d3-MeCN): δ 7.8-7.0 (30H), 1.5 (2H). 13C
NMR (d3-MeCN): δ 140.9, 135.8, 133.6, 131.9, 131.9, 131.7,
131.0, 130.8, 129.5, 128.3, 128.1, 119.3 (CF3), 5.2 (1J(13C-119
Sn) ) 455 Hz). 31P NMR (d3-MeCN): δ 34.6 (2J(31P-O-117/119
-
-
Sn) ) 66 Hz). 119Sn NMR (d3-MeCN): δ -120.9 (2J(119Sn-O-
31P) ) 69 Hz). Conductivity (c ) 3.33 mmol L-1 MeCN): 344
µS. Anal. Calcd for C38H32O5F3PSSn2 (926.11): C, 49.28; H,
3.48. Found: C, 49.06; H, 3.68. Mol wt (c ) 10.0 mmol L-1
MeCN): 902.
8. Yield: 1.18 g, 63%. Mp: 169-171 °C dec. IR (KBr): ν
3066 s, 3051 sh, 1643 m, 1629 w, 1592 w, 1482 m, 1432 s,
1265 s, 1251 s, 1238 s, 1175 m, 1130 s, 1072 m, 1031 s, 993 m,
853 w, 753 sh, 729 s, 694 s, 636 m, 502 w, 447 m, 401 w cm-1
.

Triorganotin Triflates and Diphenylphosphinates
Organometallics, Vol. 23, No. 26, 2004 6159
cm-1. Anal. Calcd for C38H35O3PSn2 (807.73): C, 56.50; H, 4.30.
Found: C, 56.62; H, 4.26. Mol wt: not measured due to poor
solubility.
metrically calculated positions using a riding model and were
refined isotropically.
15. Yield: 0.485 g, 59%. Mp: 225-229 °C. IR (KBr): ν 3404
vbr, 3048 w, 3015 w, 2988 w, 2943 w, 2905 w, 2849 w, 1479
w, 1430 m, 1331 w, 1302 w, 1280 w, 1261 w, 1153 s, 1127 s,
1071 w, 1044 s, 1021 m, 997 m, 931 w, 891 w, 853 w, 749 w,
726 s, 695 s, 619 w, 547 s, 505 w, 453 w cm-1. Anal. Calcd for
C39H37O3PSn2 (821.74): C, 56.90; H, 4.50. Found: C, 57.25;
H, 4.52. Mol wt: not measured due to poor solubility.
X-ray Crystallography. Intensity data for 4, 4‚MeCN, 5,
7, and 12 were collected on a Bruker SMART Apex CCD
diffractometer fitted with Mo KR radiation (graphite crystal
monochromator, λ ) 0.710 73 Å) to θmax via ω scans. Data were
reduced and corrected for absorption using the programs
SAINT and SADABS.41 The structure was solved by direct
methods and difference Fourier synthesis using SHELX-97
implemented in the program WinGX 2002.42 Full-matrix least-
squares refinement on F2, using all data, was carried out with
anisotropic displacement parameters applied to all non-
hydrogen atoms. Hydrogen atoms were included in geo-
Acknowledgment. The Australian Research Coun-
cil (ARC) is thanked for financial support. Dr. Jonathan
White (The University of Melbourne) is gratefully
acknowledged for the X-ray crystallography data col-
lection.
Supporting Information Available: Table of crystal data
and selected bond parameters for 4‚MeCN, as well as a figure
of 4‚MeCN, and tables of all coordinates, anisotropic displace-
ment parameters, and geometric data for 4, 4‚MeCN, 5, 7, and
12. This material is available free of charge via the Internet
at http://pubs.acs.org. Crystallographic data (excluding struc-
ture factors) for the structural analyses have been deposited
with the Cambridge Crystallographic Data Centre, CCDC Nos.
234571 for 4, 234572 for 4‚MeCN, 234573 for 5, 234574 for 7,
and 234575 for 12. Copies of this information may be obtained
free of charge from The Director, CCDC, 12 Union Road,
Cambridge CB2 1EZ, U.K. (fax +44-1223-336033; e-mail
deposit@ccdc.cam.ac.uk; web http://www.ccdc.cam.ac.uk).
(41) SMART, SAINT, and SADABS; Siemens Analytical X-ray
Instruments Inc., Madison, WI, 1999.
(42) Farrugia, L. J. J. Appl. Crystallogr. 1997, 20, 565.
OM049773C