Synthesis and characterisation of tin(IV) fluoride complexes of phosphine and arsine oxide ligands

Article abstract of DOI:10.1016/j.poly.2005.10.024

The pseudooctahedral complexes [SnF₄L₂] (L = Ph ₃PO, Ph₃AsO, Me₃PO, Me₃AsO) and [SnF₄(L-L)] (L-L = Ph₂P(O)CH₂P(O)Ph ₂, o-C₆H₄

Full text of DOI:10.1016/j.poly.2005.10.024

Polyhedron 25 (2006) 930–936
www.elsevier.com/locate/poly
Synthesis and characterisation of tin(IV) fluoride
complexes of phosphine and arsine oxide ligands
*
Martin F. Davis, William Levason , Gillian Reid, Michael Webster
School of Chemistry, University of Southampton, Highfield, Southampton, Hampshire SO17 1BJ, UK
Received 18 July 2005; accepted 22 October 2005
Available online 6 December 2005
Dedicated to Professor Mike Hursthouse on the occasion of his retirement.
Abstract
The pseudooctahedral complexes [SnF4L2] (L = Ph3PO, Ph3AsO, Me3PO, Me3AsO) and [SnF4(L–L)] (L–L = Ph2P(O)CH2P(O)Ph2,
o-C6H4(P(O)Me2)2, o-C6H4(P(O)Ph2)2) have been prepared from [SnF4(MeCN)2] and the appropriate ligand in dichloromethane solu-
1
tion. The complexes have been characterised by analysis, IR, H, 31P{1H}, 19F{1H} and 119Sn NMR spectroscopy as appropriate; the
NMR studies showing that the complexes of the monodentate ligands exist as mixtures of trans and cis isomers in solution. The crystal
structures of trans-[SnF4(OPMe3)2], [SnF4{o-C6H4(P(O)Ph2)2}] Æ CH2Cl2 Æ H2O and [o-C6H4(P(O)Ph2)2] Æ CH2Cl2 have been determined.
Comparison of the structural and NMR spectroscopic data of the tetrafluorotin complexes with those of related [SnX4L2] (X = Cl, Br or
I) shows that SnF4 is the strongest Lewis acid in the series towards hard Lewis bases.
Ó 2005 Elsevier Ltd. All rights reserved.
Keywords: Tin(IV) fluoride; Phosphine oxide; Arsine oxide
1. Introduction
and diarsines [13] and thiamacrocycles [14]. This work is
now being extended to the investigation of the SnF4
adducts and we report here of some examples with phos-
phine and arsine oxides.
Although standard texts state (usually without quoting
supporting evidence) that Lewis acidity of the four tin(IV)
halides is greatest for SnF4, remarkably few complexes of
the latter are known [1–6] and only one example with a
neutral ligand, [SnF4(2,20-bipy)], has been structurally
characterised [1]. Tin(IV) chloride and bromide are strong
Lewis acids forming adducts with a wide variety of neutral
donor ligands, whereas tin(IV) iodide is only a weak Lewis
acid forming similar, although much less stable, complexes
which are often extensively dissociated in solution [7–9].
We have reported previously the syntheses, structural and
spectroscopic characterisation (especially by multinuclear
NMR techniques) of several series of SnX4 (X = Cl, Br
or I) adducts with soft donors, including dithioethers
[10], diselenoethers [11], ditelluroethers [12], diphosphines
2. Results and discussion
2.1. [SnF4L2], L = Ph3PO, Ph3AsO, Me3PO, Me3AsO,
L2 = Ph2P(O)CH2P(O)Ph2, o-C6H4(P(O)Ph2)2,
o-C6H4(P(O)Me2)2
Unlike the other three tin(IV) halides which are tetrahe-
dral molecules, anhydrous SnF4 has a polymeric sheet
structure based upon vertex sharing SnF6 groups [15], and
as a result, although moisture sensitive, it is otherwise rather
unreactive towards neutral ligands. A convenient entry into
the chemistry is provided by [SnF4(MeCN)2] made from
SnF2, I2 and MeCN as described by Tudela [16,17]. The
reaction of [SnF4(MeCN)2] with 2.1 mol equivalents of
Ph3PO, Ph3AsO, Me3PO or Me3AsO in anhydrous CH2Cl2
*
Corresponding author. Tel.: +2380593792; fax: +2380593781.
E-mail address: wxl@soton.ac.uk (W. Levason).
0277-5387/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2005.10.024

M.F. Davis et al. / Polyhedron 25 (2006) 930–936
931
resulted in the formation of white [SnF4L2] complexes in
high yield. The solids are moisture sensitive, tenaciously
retain organic solvents – clearly evident in the H NMR
lets for the cis (Table 2), with d(19F) in the range ꢀ135 to
ꢀ170, and with 1J(119Sn–19F) 1700–1950 Hz, similar to the
values in substituted fluorostannates(IV) [3]. In these cases,
1
1
spectra, and are only modestly soluble in chlorocarbons.
Solubility is not significantly better in acetone or nitrometh-
ane and stronger donor solvents were generally avoided for
spectroscopic studies since they can lead to some displace-
ment of the neutral ligands. The complexes could be recrys-
tallised from a large volume of anhydrous CH2Cl2. The
complexes with Ph3PO, Ph3AsO and Me3PO were briefly
reported in larger compilations of their metal complexes
many years ago [4–6] but characterisation was limited to
microanalysis and partial IR spectra. Our IR spectra (Table
1) are generally in good agreement with those reported;
where differences occur they are probably attributable to
various amounts of cis and trans isomers present in the sam-
ples resulting from differences in the isolation procedures
and/or solvents used [18]. Three diphosphine dioxide com-
plexes, [SnF4{o-C6H4(P(O)Ph2)2}], [SnF4{o-C6H4(P(O)-
Me2)2}] and [SnF4{Ph2P(O)-CH2P(O)Ph2}] were made
similarly.
the J(117Sn–19F) satellites were also clearly resolved and
although not quoted in Table 2, the magnitudes were consis-
tent with expectation based upon c119Sn/c117Sn. Obtaining
good quality 119Sn NMR spectra proved difficult due to
the modest receptivity of the tin (Dc = 25), poor solubilities,
the presence of both isomers and also the complexity of the
coupling patterns. For example, for [SnF4(Me3PO)2] the
symmetrical quintet of triplets of the trans isomer was
clearly evident centred at d ꢀ781.8 Underlying this reso-
nance is another weaker and more complex pattern centred
at d ꢀ769.0 attributed to the cis isomer. Based upon the var-
ious coupling constants obtained from the 19F{1H} and
31P{1H}spectra the major lines of the expected 27 line mul-
tiplet (t,t,t) were identified. The solubility of [SnF4(Ph3PO)2]
is lower, but again two multiplets can be discerned consistent
with approximately equal amounts of the two geometric iso-
mers, although in this case the spectral quality was poor. For
the [SnF4(R3AsO)2] complexes, the quintet due to the trans
isomer was clearly identified in each case, but the resonance
(t,t) of the less abundant cis form appeared near coincident
and hence the chemical shift assignment less clear, although
the more intense lines of the multiplets were found.
The diphosphine dioxide complexes [SnF4(L–L)]
(L–L = Ph2P(O)CH2P(O)Ph2, o-C6H4(P(O)Ph2)2) are, as
expected, cis isomers showing (Table 2) two triplets in the
19F{H} NMR spectra and singlets in the 31P{1H} spectra.
At temperatures a little above ambient the resonances in
the 19F{H} NMR spectra broaden, presumably due to some
dynamic process, probably chelate ring opening. On cooling
the solutions the complexes precipitate which prevented low
temperature studies. The [SnF4{o-C6H4(P(O)Me2)2}] was
insoluble in chlorinated solvents, but dissolved with some
decomposition (diphosphine dioxide displacement) in anhy-
drous N,N-dimethylformamide The 19F{H} and 31P{1H}
NMR spectra of the complex are given in Table 2, but the
poor solubility and partial decomposition prevented a
119Sn spectrum from being obtained.
The multinuclear NMR data (Tables 1 and 2) show the
presence of both cis and trans isomers in CH2Cl2 solution
for the R3PO and R3AsO complexes, the approximate iso-
mer ratios being determined from the 19F{1H} NMR spec-
tra. For [SnF4(Ph3PO)2] the two isomers have similar
abundance but for the other three the trans isomer predom-
inates. Although resonances were observed at ambient tem-
1
peratures in the H, 31P and 19F spectra, the 119Sn spectra
showed broad and poorly resolved features and the samples
were cooled to 273 K to improve resolution. The 31P{1H}
NMR spectra show singlet resonances for each isomer with
very similar chemical shifts, and no resolved coupling to 19F,
but with weak 119/117Sn satellites. The 2J(119/117Sn–31P)
which lie in the range 20–65 Hz, appeared as single lines
rather than as separate features for the two tin isotopes –
no doubt the differences were lost in the line width, since
from the magnetogyric ratios c119Sn/c117Sn (1.046) the val-
ues are expected to differ by <2 Hz. The 19F{1H} spectra
show singlet resonances for the trans isomers and two trip-
Table 1
IRa and 1H NMRb spectroscopic data
Compound
m(P(As)O) (cmꢀ1
)
m(Sn–X) (cmꢀ1
)
d(1H)
[SnF4(Ph3PO)2]
[SnF4(Me3PO)2]
1137, 1082
1085(br)
580, 549, 537
576, 559
7.36–7.88(m)
2
1.855(d), JPH = 13.5 Hz
2
1.860(d), JPH = 13.5 Hz
[SnF4(Ph3AsO)2]
[SnF4(Me3AsO)2]
[SnF4{o-C6H4(P(O)Ph2)2}]
[SnF4{Ph2P(O)CH2P(O)Ph2}]
877(br), 850(sh)
865, 812(br)
1145, 1087(br)
1145, 1092
559(br)
550(br)
585, 569, 548
596, 577
7.40–7.87(m)
2.04(s), 2.05(s)
7.31–7.71(m)
2
4.00(t), JPH = 13 Hz
7.36–7.75(m)d
1.81(m)
[SnF4{o-C6H4(P(O)Me2)2}]
1147, 1093
573(br)
7.49–7.85(m)c
a
Nujol mull.
In CDCl3 at 300 MHz.
In d6-dmso.
b
c
d
In CD2Cl2.

932
M.F. Davis et al. / Polyhedron 25 (2006) 930–936
Table 2
31P{1H}, 119Sn and 19F{1H} NMR spectroscopic dataa
Compound
d31P{1H}b
d119Snc
d19F{1H}d
1J(19F–119Sn)
2J(19F–19F)
2J(31P–119Sn)
Isomer ratio
[SnF4{Me3PO)2] trans
cis
65.9(s)
65.4(s)
ꢀ781.8(q,t)
ꢀ769.0(t,t,t)
ꢀ149.2(s)
ꢀ147.2(t)
ꢀ158.0(t)
ꢀ149.8(s)
ꢀ146.2(t)
ꢀ159.8(t)
ꢀ141.6(s)
ꢀ140.9(t)
ꢀ148.2(t)
ꢀ141.3(s)
ꢀ137.8(t)
ꢀ151.9(t)
ꢀ142.9(br)
ꢀ167.2(t)
ꢀ143.0(t)
ꢀ167.8(t)
ꢀ143.5(t)
ꢀ165.4(t)
1725
1772
1850
1704
1730
1850
1804
1827
1818
1788
1800
1860
1730
1923
1753
1930
1740
1930
50
50
3
1
51
[SnF4(Ph3PO)2] trans
cis
42.5(s)
42.3(s)
ꢀ770.0(q,t)
ꢀ775.1(t,t,t)
20
22
1
1
53
49
[SnF4{Me3AsO)2] trans
cis
ꢀ747.7(q)
ꢀ748.4(t,t)
3
1
[SnF4(Ph3AsO)2] trans
cis
ꢀ757.5(q)
ꢀ758.6(t,t)
2
1
51
53
50
50
[SnF4{o-C6H4(P(O)Ph2)2}]
[SnF4{Ph2P(O)CH2P(O)Ph2}]
[SnF4{o-C6H4(P(O)Me2)2}]e
a
45.5(s)
44.1(s)
62.1(s)
ꢀ790.0(t,t,t)
ꢀ792.4(t,t,t)
63
57
57
To obtain good resolution of the complex couplings, spectra were typically recorded at 273 K.
Relative to external 85% H3PO4.
Relative to external neat SnMe4.
Relative to external CFCl3.
b
c
d
e
N,N-Dimethylformamide solution.
2.2. Structures of trans-[SnF4(Me3PO)2], [SnF4-
{o-C6H4(P(O)Ph2)2}] and [o-C6H4(P(O)Ph2)2]
F1
C3
Colourless crystals of [SnF4(Me3PO)2] were grown from
a sample containing both isomers by vapour phase diffu-
sion of hexane into a CH2Cl2 solution. These proved on
structure solution to be the trans isomer (Table 3 and
Fig. 1). The molecule is centrosymmetric with Sn–F =
P1
C2
Sn1
O1
F2
˚
1.937(2), 1.954(2) A, not significantly different from the
C1
0
˚
values in cis-[SnF4(2,2 -bipy)] 1.924(3)–1.948(3) A [1].
˚
Comparison of d(P–O) in the complex (1.532(3) A) with
that in Me3PO (1.489(6) A) [19] shows the bond is signifi-
Fig. 1. Structure of trans-[SnF4(Me3PO)2] showing the atom numbering
scheme. Atomic displacement ellipsoids are drawn at the 50% probability
level and H atoms omitted for clarity. There is a centre of symmetry at the
Sn1 atom.
˚
cantly lengthened upon coordination.
The crystal structures of (cis) [SnF4{o-C6H4(P(O)Ph2)2}]
(Table 4, Fig. 2) and of the parent ligand, o-C6H4-
(P(O)Ph2)2 (Table 5, Fig. 3) have also been determined
and the key bond lengths may be compared similarly.
The d(Sn–F) are very similar to those in [SnF4(Me3PO)2],
and essentially independent of the nature of the trans
ligand. The d(Sn–O) at 2.088(5) and 2.071(5) A are rather
longer than in the Me3PO complex which probably reflects
the effect of the seven-membered chelate ring. As found for
Table 4
˚
Selected bond lengths (A) and angles (°) for [SnF4{o-C6H4-
(P(O)Ph2)2}] Æ CH2Cl2 Æ H2O
˚
Sn1–F1
Sn1–F2
Sn1–O1
P1–O1
P–C
1.951(4)
1.941(4)
2.088(5)
1.512(5)
Sn1–F3
Sn1–F4
Sn1–O2
P2–O2
1.930(4)
1.940(4)
2.071(5)
1.525(5)
1.786(7)–1.819(7)
F1–Sn1–F2
F1–Sn1–F3
F1–Sn1–F4
F1–Sn1–O1
F2–Sn1–O1
F3–Sn1–O1
F4–Sn1–O1
O1–Sn1–O2
P1–O1–Sn1
O–P–C
174.39(18)
93.20(18)
91.00(18)
89.18(18)
87.67(17)
91.13(18)
173.19(18)
84.40(18)
140.5(3)
F2–Sn1–F3
F2–Sn1–F4
F3–Sn1–F4
F1–Sn1–O2
F2–Sn1–O2
F3–Sn1–O2
F4–Sn1–O2
91.50(18)
91.57(17)
95.65(19)
87.81(18)
87.26(18)
175.41(19)
88.80(19)
Table 3
a
˚
Selected bond lengths (A) and angles (°) for trans-[SnF4(Me3PO)2]
Sn1–F1
Sn1–O1
P1–C
1.937(2)
2.045(3)
1.774(4)–1.782(4)
Sn1–F2
P1–O1
1.954(2)
1.532(3)
F1–Sn1–F2
F2–Sn1–O1
O1–P1–C
a
89.85(10)
89.48(10)
108.4(2)–111.7(2)
F1–Sn1–O1
P1–O1–Sn1
C–P1–C
91.13(11)
131.50(17)
107.2(2)–110.2(2)
P2–O2–Sn1
C–P–C
133.8(3)
106.9(3)–109.6(3)
106.5(3)–112.9(3)
The tin atom is on a centre of symmetry.

M.F. Davis et al. / Polyhedron 25 (2006) 930–936
933
C21
C8
C7
C14
C22
C25
C20
C26
C30
C1
C13
C18
P1
O1
P2
O2
C2
Sn1
F1
F2
F3
F4
Fig. 2. Structure of the tin residue in [SnF4{o-C6H4(P(O)Ph2)2}] Æ CH2Cl2 Æ H2O showing the atom numbering scheme. Atomic displacement ellipsoids are
drawn at the 50% probability level and H atoms omitted for clarity.
hard donor–acceptor interactions on a p-block metal. How-
ever, when one compares the key distances along the series
[SnX4(R3PO)2] (Table 6) one finds that Sn–O increases with
X F < Cl < Br < I. The substantially shorter Sn–O distance
in the tin(IV) fluoride is clearly consistent with stronger
binding of the ligand indicative of stronger Lewis acidity
of the SnF4. Moreover, studies of phosphine oxide com-
plexes of hard early transition metals such as Y(III) or
Sc(III) have shown that the metal–oxygen distances are
independent of the R group (Me or Ph), although they do
vary with the metal coordination number [20,21]. From
Table 6 it is also notable that the P–O distance in the fluo-
ride complex is markedly longer than in the other examples,
(albeit some of the comparator data are not of high preci-
sion) which also supports stronger donation from O ! Sn.
The trends are replicated in [SnF4{o-C6H4(P(O)Ph2)2}]
where the data in Table 4 can be compared with the struc-
tural data on [SnI4{o-C6H4(P(O)Ph2)2}] [13] (Table 6). In
the iodo-complex the d(Sn–O) are much longer, consistent
with the relative Lewis acidity of the tin centres.
Table 5
Selected bond lengths (A) and angles (°) for [o-C6H4(P(O)Ph2)2] Æ CH2Cl2
˚
P1–O1
P1–C1
P1–C7
P1–C13
1.484(2)
1.809(3)
1.810(3)
1.824(3)
P2–O2
1.485(2)
1.838(3)
1.800(3)
1.815(3)
P2–C18
P2–C19
P2–C25
O1–P1–C1
O1–P1–C7
O1–P1–C13
C1–P1–C7
C1–P1–C13
C7–P1–C13
115.74(13)
110.22(12)
112.88(13)
105.49(13)
105.77(13)
106.02(13)
O2–P2–C18
O2–P2–C19
O2–P2–C25
C18–P2–C19
C18–P2–C25
C19–P2–C25
114.46(12)
116.22(13)
109.84(12)
105.81(13)
104.88(13)
104.60(13)
the Me3PO case, coordination of the diphosphine dioxide
to the SnF4 results in a significant lengthening of the P–O
bond, from 1.484(2), 1.485(2) in the ‘‘free’’ ligand to
˚
1.512(5), 1.525(5) A in the complex. A few poor quality
crystals were also obtained from a solution of [SnF4{o-
C6H4(PMe2)2}] in CH2Cl2 after several weeks. X-ray exam-
ination of these established them as the compound
[SnClF3{o-C6H4(P(O)Me2)2}] containing
a
chelating
diphosphine dioxide. The origin of the chlorine atom is
presumably from reaction with the solvent and the oxygen
in the phosphine oxide from aerial oxidation.1
2.3. [SnX4L2] X = Cl, Br or I; L = Ph3PO, Ph3AsO or
Me3PO – some comparisons
Most interesting is the comparison with data on other
tin(IV) phosphine oxides. Tudela [18] noted that in
cis- and trans-[SnBr4(Ph3PO)2] the Sn–O (2.080(8),
2.101(9) A) and P–O (1.515(8), 1.516(9)(av) A) distances
were the same within the usual criteria showing that the geo-
metric isomer present has no effect, as might be expected for
These complexes have been studied on several occasions
and structures have been reported for cis-[SnX4(Ph3PO)2]
(X = Cl or Br) [18,23,25] and trans-[SnBr4(Ph3PO)2] [22,24].
The IR spectra have been discussed in detail [5,6,26] and
our data are generally in agreement with the literature and
hence not discussed further. Curiously, little NMR data
have been reported previously and complete data are pre-
sented in Table 7. As can be seen, whilst both isomers
are present in CH2Cl2 solutions of the chloro-complexes,
only one isomer was present for the iodo-complexes, and
only small amounts or essentially none of the second form
˚
˚
1
Crystal data for [SnClF3{o-C6H4(P(O)Me2)2}] Æ 1/2CH2Cl2: Mw
=
483.77; orthorhombic, space group Pbcn (no. 60), Z = 8, T = 120 K,
3
˚
˚
a = 15.290(5)°, b = 17.266(6)°, c = 13.380(3) A, V = 3532.3(19) A ; 3772
unique data gave R1 = 0.095, wR2 = 0.173(I > 2r(I)) based on 186 inde-
pendent parameters with S = 0.95.

934
M.F. Davis et al. / Polyhedron 25 (2006) 930–936
C23
C15
C16
C24
C19
C22
C21
C9
C10
C14
C8
C17
C18
C13
C29
C7
C11
C20
C25
C30
O1
C12
P2
P1
C28
C1
O2
C26
C2
C27
C6
C3
C4
C5
Fig. 3. Structure of [o-C6H4(P(O)Ph2)2] Æ CH2Cl2 showing the atom numbering scheme. Atomic displacement ellipsoids are drawn at the 50% probability
level and H atoms omitted for clarity.
Table 6
clusions from the X-ray data above. The 119Sn NMR data
are not useful in this respect since the chemical shifts reflect
Selected structural data on tin(IV) phosphine oxides
Compound
d(Sn–O)
(A)
d(P–O)
(A)
Ref.
a number of competing factors including electronegativity
of the substituents, mutual ligand interactions and ligand
polarisabilities [7,29]. The shift to low frequency
[SnCl4(R3EO)2] > [SnF4(R3EO)2] > [SnBr4(R3EO)2] paral-
lels that in the hexahalostannates(IV) [27–29]. Tin-119 res-
onances are rarely observed for iodotin species mainly due
to exchange reactions in solution resulting from the weak
Lewis acidity of SnI4. The data show that SnF4 is the stron-
gest Lewis acid in the series SnX4 (X = F, Cl, Br, I)
towards hard bases.
˚
˚
trans-[SnF4(Me3PO)2]a
cis-[SnCl4(Ph3PO)2]b
cis-[SnCl4(Ph3PO)2]c
trans-[SnBr4(Ph3PO)2]b
2.045(3)
2.083(2)
2.086(2)
2.102(9),
2.100(8)
2.080(8)
2.11(2),
2.15(2)
2.071(5),
2.088(5)
2.120(5),
2.138(5)
1.532(3)
1.510(2)
1.505(2)
1.504(9),
1.527(9)
1.515(8)
1.47(2),
1.50(2)
1.512(5),
1.525(5)
1.509(6),
1.513(5)
this work
[22]
[23]
[24]
cis-[SnBr4(Ph3PO)2]b
cis-[SnI4(Ph3PO)2]b
[18]
[25]
[SnF4{o-C6H4(P(O)Ph2)2}]a
[SnI4{o-C6H4(P(O)Ph2)2}]d
this work
[13]
3. Experimental
a
120 K.
295 K.
90 K.
150 K.
b
All compounds were made under a dinitrogen atmo-
sphere using dry solvents and standard Schlenk and glove
box techniques. SnF2, SnCl4, SnBr4 and SnI4 were obtained
from Aldrich and used as received. [SnF4(MeCN)2] and
[SnF4(THF)2] were made as described [17]. Ligands
were obtained from Aldrich (Me3PO, Ph3PO, Ph3AsO)
and were dried by heating in vacuo before use. Other
ligands were made by literature methods: o-C6H4(P(O)-
Ph2)2, o-C6H4(P(O)Me2)2, Me3AsO, Ph2P(O)CH2P(O)Ph2
[13,30,31]. IR spectra were recorded as Nujol mulls on a
c
d
in the bromo-complexes. The complexes are labile in solu-
tion and cooling the samples is necessary to observe sharp
resonances and resolve couplings; the temperatures at
which the presented data were obtained are given in Table
7. The trends in the spectroscopic data were also examined
to see if support for the greater Lewis acidity of the SnF4
was forthcoming. The IR data, specifically the m(PO), are
not useful due to the broadness of the bands and the pres-
ence of overlapping bands of the geometric isomers, but
even if this were not the case, coupling with other vibra-
tions would complicate any comparisons. The 31P{1H}
NMR data are more useful (Tables 2 and 7). The chemical
shift differences between the geometric isomers are small
and therefore one can compare directly the changes in
chemical shift simply as a function of the halide present.
This shows a small but clear shift to high frequency along
the series F > Cl > Br > I consistent with decreased accep-
tor power along this series and in agreement with the con-
1
Perkin Elmer PE 983G spectrometer, H NMR spectra in
CDCl3 solutions on a Bruker AV300, 31P{1H}, 19F{1H}
and 119Sn NMR spectra on a Bruker DPX400 and refer-
enced to 85% H3PO4, CFCl3 and neat SnMe4, respectively.
Microanalytical measurements were performed by the
microanalytical service, Strathclyde University.
3.1. [SnF4(Ph3PO)2]
[SnF4(MeCN)2] (0.277 g, 1.0 mmol) was suspended in
CH2Cl2 (20 mL) and Ph3PO (0.612 g, 2.2 mmol) added

M.F. Davis et al. / Polyhedron 25 (2006) 930–936
935
Table 7
Selected NMR data on comparator complexes
Compound
d31P{1H}a
+63.4 (273 K)c
2J(31P–119Sn) (Hz)b
d
119Sn
Ratio of isomers
[SnCl4(Me3PO)2]
140
106
140
n.o.
198
162
214
n.o.
ꢀ695(t) (243 K)
ꢀ686(t)
4
1
+62.5
[SnBr4(Me3PO)2]
[SnI4(Me3PO)2]
[SnCl4(Ph3PO)2]
+61.0 (223 K)
+58.3 (193 K)
+40.8 (233 K)
+40.35
+38.9 (223 K)
+36.5 (183 K)
ꢀ1439(t)
n.o.d
ꢀ710(t) (233 K)
1
5
ꢀ698(t)
[SnBr4(Ph3PO)2]
[SnI4(Ph3PO)2]
[SnCl4(Ph3AsO)2]
ꢀ1480(t) (223 K)
n.o.
ꢀ639(s) (243 K)
1
2
ꢀ637(s)
[SnBr4(Ph3AsO)2]
[SnI4(Ph3AsO)2]
[SnCl4{o-C6H4(P(O)Ph2)2}]e
[SnBr4{o-C6H4(P(O)Ph2)2}]e
[SnI4{o-C6H4(P(O)Ph2)2}]e
ꢀ1364(s) (233 K)
n.o.
+42.4 (295 K)
+41.6 (295 K)
+39.8 (295 K)
a
In CH2Cl2–10% CDCl3.
b
Separate resonances for 119Sn and 117Sn couplings not resolved in 31P NMR spectra, couplings are from 119Sn spectra.
Ligand chemical shifts are: Me3PO + 38, Ph3PO + 28, o-C6H4(P(O)Ph2)2 + 31.
n.o., Not observed in temperature range 295–180 K.
c
d
e
Data from [13].
and the mixture stirred at room temperature for 2 h. The
3.6. [SnF4{Ph2P(O)CH2P(O)Ph2}]
white solid was filtered off, recrystallised from hot CH2Cl2
and dried in vacuo. Yield: 0.66 g, 88%. Anal. Calc. for
C36H30F4O2P2Sn Æ 3CH2Cl2: C, 46.6; H, 3.6. Found: C,
47.1; H, 3.7%.
Powdered Ph2P(O)CH2P(O)Ph2 (0.22 g, 0.53 mmol) and
[SnF4(MeCN)2] (0.133 g, 0.48 mmol) were dissolved in
CH2Cl2 (10 mL) and stirred at room temperature over-
night. The white precipitate was then filtered off and dried
in vacuo. Yield: 0.27 g, 92%. Anal. Calc. for
C25H22F4O2P2Sn Æ 0.5CH2Cl2: C, 46.9; H, 3.6. Found: C,
46.5; H, 3.7%.
3.2. [SnF4(Ph3AsO)2]
Prepared similarly from [SnF4(MeCN)2] (0.156 g,
0.56 mmol) and Ph3AsO (0.40 g, 1.24 mmol). Yield:
0.30 g, 64%. Anal. Calc. for C36H30As2F4O2Sn Æ 2CH2Cl2:
C, 45.2; H, 3.4. Found: C, 45.3; H, 3.2%.
3.7. [SnF4{o-C6H4(P(O)Me2)2}]
[SnF4(THF)2] (0.30 g, 0.88 mmol) was dissolved in
CH2Cl2 (5 mL), o-C6H4(P(O)Me2)2 (0.20 g, 0.87 mmol) dis-
solved in CH2Cl2 (5 mL) was added and the mixture stirred
at room temperature for 2 h. The white solid was filtered
off and dried in vacuo. Yield: 0.257 g, 68%.
3.3. [SnF4(Me3PO)2]
Prepared similarly from [SnF4(MeCN)2] (0.28 g,
1.0 mmol) and Me3PO (0.19 g, 2.05 mmol) and stirred for
8 h. Yield: 0.30 g, 79%. Anal. Calc. for C6H18F4O2P2Sn:
C, 19.0; H, 4.8. Found: C, 18.2; H, 4.7%.
3.8. [SnX4L2] (X = Cl, Br or I; L = Ph3PO, Ph3AsO or
Me3PO)
3.4. [SnF4(Me3AsO)2]
These were made by reaction of the anhydrous tin(IV)
halide with the ligand in anhydrous CH2Cl2 using literature
methods [6,26].
Prepared similarly from [SnF4(MeCN)2] (0.32 g,
1.15 mmol) and Me3AsO (0.34 g, 2.5 mmol). Yield:
0.495 g, 92%.
3.9. X-ray experimental
3.5. [SnF4{o-C6H4(P(O)Ph2)2}]
Crystals of [SnF4{o-C6H4(P(O)Ph2)2}] Æ CH2Cl2 Æ H2O
were obtained from CH2Cl2 solution layered with hexane
and o-C6H4(P(O)Ph2)2 from CH2Cl2 solution. Brief details
of the data collection and refinement are presented in
Table 8. Data collection used a Bruker–Nonius Kappa
CCD diffractometer with the crystal held at 120 K in a cold
nitrogen stream. Structure solution [32] and refinement [33]
[SnF4(MeCN)2] (0.138 g, 0.50 mmol) and o-C6H4(P(O)-
Ph2)2 (0.239 g, 0.50 mmol) were stirred together for 0.5 h
in CH2Cl2 (20 mL). The white precipitate was filtered off
and dried in vacuo. Yield: 0.23 g, 68%. Anal. Calc. for
C30H24F4O2P2Sn Æ 0.5CH2Cl2: C, 51.2; H, 3.5. Found: C,
51.2; H, 3.3%.

936
M.F. Davis et al. / Polyhedron 25 (2006) 930–936
Table 8
Crystallographic dataa
Compound
[SnF4(Me3PO)2]
[SnF4{o-C6H4(P(O)Ph2)2}] Æ CH2Cl2 Æ H2O
[o-C6H4(P(O)Ph2)2] Æ CH2Cl2
Formula
C6H18F4O2P2Sn
378.83
C31H28Cl2F4O3P2Sn
776.06
C31H26Cl2O2P2
563.36
Formula weight
Crystal system
Space group
monoclinic
P21/n (no. 14)
6.190(2)
11.089(4)
9.504(3)
94.32(3)
650.5(4)
2
monoclinic
P21/c (no. 14)
17.579(3)
10.1696(15)
18.178(4)
99.160(8)
3208.2(10)
4
monoclinic
P21/c (no. 14)
10.840(2)
14.734(3)
17.576(2)
104.467(12)
2718.3(8)
4
˚
a (A)
˚
b (A)
˚
c (A)
b (°)
3
˚
U (A )
Z
l(Mo Ka) (mmꢀ1
)
2.24
1.12
0.38
Total no. of observations
No. of unique observations (Rint
No. of parameters, restraints
R1, wR2 (I > 2r(I))b
R1, wR2 (all data)
6333
1486 (0.056)
71, 0
0.034, 0.073
0.049, 0.079
35141
7058 (0.055)
395, 5
0.070, 0.183
0.082, 0.188
28169
4775 (0.101)
335, 0
0.046, 0.095
0.088, 0.112
)
a
˚
Other items: temperature = 120 K; wavelength (Mo Ka) = 0.71073 A; hmax = 27.5°.
P
P
P
P
2
1=2
b
R1 = iFo| ꢀ |Fci/ jFoj, wR2 ¼ ½ wðF 2o ꢀ F c2Þ = wF o4ꢂ
.
[7] P.G. Harrison, The Chemistry of Tin, Blackie & Son, London,
1989.
[8] S.J. Ruzicka, A.E. Merbach, Inorg. Chim. Acta 20 (1976) 221.
[9] S.J. Ruzicka, A.E. Merbach, Inorg. Chim. Acta 22 (1977) 191.
[10] S.E. Dann, A.R.J. Genge, W. Levason, G. Reid, J. Chem. Soc.,
Dalton Trans. (1996) 4471.
[11] S.E. Dann, A.R.J. Genge, W. Levason, G. Reid, J. Chem. Soc.,
Dalton Trans. (1997) 2207.
[12] A.R.J. Genge, W. Levason, G. Reid, J. Chem. Soc., Dalton Trans.
(1997) 4549.
were routine. In [SnF4{o-C6H4(P(O)Ph2)2}] Æ CH2Cl2 Æ H2O
the CH2Cl2was disordered with one of the chlorine atoms
occupying three sites. The two remaining peaks in the dif-
ference map were interpreted as half occupancy water mol-
ecules with the Oꢁ ꢁ ꢁO distance appropriate for an H-bond.
No H atoms were included for these solvate molecules. Sev-
eral attempts were made to grow X-ray quality crystals of
[SnF4(Me3AsO)2] by vapour diffusion from EtOH and
Et2O. The data from the crystals obtained did not lead to
a structure possibly due to twinning.
[13] A.R.J. Genge, W. Levason, G. Reid, Inorg. Chim. Acta 288 (1999)
142.
[14] W. Levason, M.L. Matthews, R. Patel, G. Reid, M. Webster, New J.
Chem. 27 (2003) 1784.
[15] M. Bork, R. Hoppe, Z. Anorg. Allgem. Chem. 622 (1996) 1557.
[16] D. Tudela, F. Rey, Z. Anorg. Allgem. Chem. 575 (1989) 202.
[17] D. Tudela, J.A. Patron, Inorg. Synth. 31 (1997) 92.
4. Supplementary data
Crystallographic data in cif format have been deposited
with the Cambridge Crystallographic Data Centre (CCDC)
and given numbers 278050–278052. Copies of the data can
be obtained free of charge from The Director, CCDC, 12
Union Road, Cambridge, CB2 1EZ, UK, fax: +44 1223
366 033, e-mail: deposit@ccdc.ac.uk or on the web www:
http://www.ccdc.cam.ac.uk.
´
[18] D. Tudela, J.D. Tornero, A. Monge, A.J. Sanchez-Herencia, Inorg.
Chem. 32 (1993) 3928.
[19] L.M. Engelhardt, C.L. Raston, C.R. Whitaker, A.H. White, Aust. J.
Chem. 39 (1986) 2151.
[20] L. Deakin, W. Levason, M.C. Popham, G. Reid, M. Webster, J.
Chem. Soc., Dalton Trans. (2000) 2439.
[21] N.J. Hill, W. Levason, M.C. Popham, G. Reid, M. Webster,
Polyhedron 21 (2002) 445.
[22] A.I. Tursina, L.A. Aslanov, S.V. Medvedev, A.V. Yatsenko, Koord.
Khim. 11 (1985) 417.
Acknowledgements
[23] T. Szymanska-Buzar, T. Glowiak, I. Czelusniak, Main Group Met.
Chem. 24 (2001) 821.
[24] A.I. Tursina, A.V. Yatsenko, S.V. Medvedev, V.V. Chernyshev,
L.A. Aslanov, Zh. Strukt. Khim. 27 (1986) 157.
[25] A.I. Tursina, L.A. Aslanov, V.V. Chernyshev, S.V. Medvedev, A.V.
Yatsenko, Koord. Khim. 12 (1986) 420.
We thank EPSRC for support (MFD), and M.J. Dar-
mody for the preparation of some of the tin(IV) complexes
in Section 3.8.
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