Novel triphenyltin substituted derivatives of heavier alkaline earth metals

Article abstract of DOI:10.1016/S0022-328X(00)00440-X

The synthesis and characterization of a family of novel alkaline earth metal stannides, in addition to tri- and pentastannanes are described. [Ba(18-crown-6)(HMPA)₂][SnPh₃]₂ (4), [Ca(18-crown-6)(HMPA)₂][Sn(SnPh₃)₃]₂ (5), and [Sr(18-crown-6)(HMPA)₂][Sn(SnPh₃)₃]₂ (6) were synthesized by insertion of the corresponding alkaline earth metals into the tin-tin bond of hexaphenyldistannane. Ph₃SnSnPh₂SnPh₃ (7), and Sn(SnPh₃)₄ (8) became available by treating 4 with diphenyldichlorostannane. All compounds were studied by NMR spectroscopy, and X-ray crystallography. The stannanes 7 and 8 were also characterized by elemental analysis.

Full text of DOI:10.1016/S0022-328X(00)00440-X

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 613 (2000) 139–147
Novel triphenyltin substituted derivatives of heavier alkaline earth
metals
Ulrich Englich a, Karin Ruhlandt-Senge* a,1, Frank Uhlig* b,2
a Department of Chemistry and the W.M. Keck Center for Molecular Electronics 1-014 Center for Science and Technology, Syracuse Uni6ersity,
Syracuse, NY 13244-4100, USA
b Department of Chemistry, Institut fu¨r Anorganische Chemie II, Uni6ersita¨t Dortmund, D-44221 Dortmund, Germany
Received 2 June 2000; received in revised form 23 June 2000
Abstract
The synthesis and characterization of a family of novel alkaline earth metal stannides, in addition to tri- and pentastannanes
are described. [Ba(18-crown-6)(HMPA)2][SnPh3]2 (4), [Ca(18-crown-6)(HMPA)2][Sn(SnPh3)3]2 (5), and [Sr(18-crown-6)(HMPA)2]-
[Sn(SnPh3)3]2 (6) were synthesized by insertion of the corresponding alkaline earth metals into the tinꢀtin bond of hexaphenyld-
istannane. Ph3SnSnPh2SnPh3 (7), and Sn(SnPh3)4 (8) became available by treating 4 with diphenyldichlorostannane. All
compounds were studied by NMR spectroscopy, and X-ray crystallography. The stannanes 7 and 8 were also characterized by
elemental analysis. © 2000 Elsevier Science B.V. All rights reserved.
Keywords: Alkaline earth metal stannides; Stannanes; 119Sn-NMR spectroscopy; Structure elucidation
1. Introduction
polymerization initiators [8], we were interested to ex-
plore the chemistry of the heavy alkaline earth metals
calcium, strontium, and barium with hexaphenyldistan-
nane. This paper describes the results of this work,
including the reaction of the calcium, strontium, and
barium stannides with hydrochloric acid and
chlorostannanes.
Alkali metal stannides are well established starting
materials for tin–element coupling reactions. Accord-
ingly, alkali metal–tin derivatives have received signifi-
cant attention [1–4]. In contrast, little is known about
the corresponding alkaline earth metal derivatives, de-
spite the well documented use of magnesium com-
pounds in Wurtz-type tin chemistry [5,6].
Well characterized alkaline earth metal stannides are
to the best of our knowledge limited to
Ca(THF)4(SnMe3)2 (1), synthesized and structurally
characterized in 1996 by Westerhausen [7]. Compound
1 became available by treating hexamethyldistannane
with elemental calcium Eq. (1).
2. Results and discussion
2.1. Synthesis
Alkali and alkaline earth metal stannides can be
synthesized by reductive insertion of the alkaline earth
metals into the tinꢀtin bond of hexaorganodistannanes,
as shown previously with the synthesis of
Ca(THF)4(SnMe3)2 [7]. Westerhausen reports extended
reaction times (3 days), probably due to the limited
calcium surface area in this heterogeneous reaction.
Significant reduction of reaction time in this synthetic
scheme can be achieved by dissolving the alkaline earth
metals and the distannanes in dry, liquid ammonia Eq.
(2). The main products in this reaction are alkaline
earth metal stannides MII[SnPh3]2 (2–4), isolated as
colorless solids.
Me3SnꢀSnMe3+Ca“Ca(THF)4[SnMe3]2
(1)
1
Since magnesium stannides are important intermedi-
ates in the formation of silicon-tin moieties [6], and
calcium stannides have been shown to be effective
1 *Corresponding author. Tel.: +1-315-4431305; fax: +1-315-
4434070; e-mail: kruhland@syr.edu.
2 *Corresponding author. Tel.: +49-231-7553812; fax.: +49-231-
7555048; e-mail: fuhl@platon.chemie.uni-dortmund.
0022-328X/00/$ - see front matter © 2000 Elsevier Science B.V. All rights reserved.
PII: S0022-328X(00)00440-X

140
U. Englich et al. / Journal of Organometallic Chemistry 613 (2000) 139–147
Ph3SnꢀSnPh3+MII“MII[SnPh3]2
2, MII=Ca; 3, MII=Sr; 4, MII=Ba
(2)
The reaction of 4 with diphenyldichlorostannane re-
sulted in the formation of octaphenyltristannane (7),
and hexaphenyldistannane (Scheme 1). The two prod-
ucts were separated by crystallization. The presence of
Ph3SnSnPh3 can not only be explained by an incom-
plete reaction, but also as the result of a transmetalla-
tion process, under formation of Ph3SnSnPh3, BaCl2
and polystannanes (Scheme 1).
Treatment of the crude reaction mixture of the stan-
nides 2–4 with a solution of anhydrous HCl in di-
ethylether resulted in the formation of a precipitate
containing alkaline earth metal dichlorides, and a solu-
tion consisting of various tin derivatives, identified by
119Sn-NMR as Ph3SnCl (ꢀ70%), Ph3SnSnPh3 (ꢀ25%,
unreacted starting material), and trace amounts of
SnPh4 Eq. (3).
Analogously, treatment of
5
or
6
with
triphenylchlorostannane results in the formation of te-
trakis[triphenylstannyl]stannane (8) Eq. (5)
excess
MII[Sn(SnPh3)3]2+2Ph3SnꢀCl“Sn(SnPh3)4 +2MIICl2
MII(SnPh3)2 ꢀꢀꢀꢀꢀꢁ MIICl2+2Ph3SnCl
(3)
8
HCL
(5)
The formation of the triphenyltinchloride via triphenyl-
tinhydride proves the formation of compounds 2–4.
The addition of 18-crown-6 and HMPA (hexamethyl
phosphoric triamide) to a DME (dimethoxyethane)
solution of barium stannide resulted in the isolation
and crystallographic characterization of [Ba(18-crown-
6)(HMPA)2][SnPh3]2 (4).
5, MII=Ca; 6, MII=Sr
Compounds 7 and 8 were obtained previously by
either reacting diphenyldichlorostannane with lithium
triphenylstannide; the reaction of lithiumstannides with
SnCl4; or treating triphenylchlorostannanes and SnCl4
with elemental lithium. However, no crystallographic
data were reported [12,13].
Surprisingly, the analogous reaction with calcium
and strontium led to the isolation and subsequent crys-
tallographic characterization of the more complex alka-
2.2. Structural descriptions/discussions
line
earth
metal
stannides
[MII(18-crown-6)
(HMPA)2][Sn(SnPh3)3]2 (5, MII=Ca; 6, MII=Sr),
2.2.1. [Ba(18-crown-6)(HMPA)2][SnPh3]2 (4):
compound 4, depicted in Fig. 1, consists of separated
cation and anions
formed concurrently with SnPh4 Eq. (4).
MII[SnPh3]2+6Ph3Sn−SnPh3
The barium atom, located on a center of symmetry,
is surrounded by one 18-crown-6 macrocycle, in addi-
tion to two HMPA molecules located in trans position
to each other, resulting in an overall coordination
number at barium of eight. The BaꢀO (crown ether)
“MII[Sn(SnPh3)3]2+6SnPh4
5, MII=Ca; 6, MII=Sr
(4)
The migration of phenyl and methyl groups in organ-
otin chemistry has been well documented [9]. Examples
include the reaction of elemental lithium with SnPh4 in
liquid ammonia, yielding [Li(NH3)4][Sn(SnPh3)3].C6H6
[4], or the treatment of either 1 [7] or LiSnMe3 [10] with
an excess of Sn2Me6. Phenyl migration has also been
observed in related alkali metal derivatives. Wright et
al. report on a triphenyllead derivative which decom-
poses within 12 h at room temperature [11]. The de-
composition pathway seems to involve migration of a
phenyl group under formation of PbPh4 and elemental
lead. Indeed, if solutions containing compounds 4–6
are kept at room temperature, the formation of a black
powder, presumably tin, is observed. Colorless crystals
obtained from these solutions contained SnPh4.
,
distances range from 2.770(2) to 2.810(1) A, while
,
BaꢀO (HMPA) distances are observed at 2.567(2) A.
The tin atom in the independent SnPh3 anion is pyrami-
dal with a sum of angles at Sn of 290.3°. There is no
,
contact below 5 A between cation and anions.
The comparison of structural features between 4 and
1, indicates that both compounds contain triorganotin
anions, but compound 1 displays cation-anion contacts,
whereas 4 exhibits separated cation and anions. Several
factors contribute towards the different ion association
in compounds 1 and 4. In compound 1, only THF
donors are available to saturate the metal center. THF
is a relatively weak Lewis base compared to the multi-
dentate crown ether, and the strong donor HMPA.
Consequently, the formation of a separated cation in 1,
saturated with only THF is energetically not preferred
over donation. In compound 4 however, solvation with
the strong donors 18-crown-6 and HMPA is energeti-
cally preferred over a presumably weak alkaline earth
metal–tin interaction. Another factor favoring the for-
mation of separated rather than contact ions is the
sterically more encumbered [SnPh3]− in 4, compared to
the smaller [SnMe3]− [7].
Scheme 1. Reaction of 4 with diphenyldichlorostannane.

U. Englich et al. / Journal of Organometallic Chemistry 613 (2000) 139–147
141
Fig. 1. Crystal structure of 4 with anisotropic displacement parameters depicting 30% probability. The hydrogen atoms have been omitted for
clarity.
Fig. 2. Crystal structure of 5 with anisotropic displacement parameters depicting 30% probability. The hydrogen atoms have been omitted for
clarity.
The [SnPh3]− anion (sum of angles 290.3°) exhibits a
significant distortion from tetrahedral geometry, closely
related to the separated [K(18-crown-6][SnPh3] [2b],
with a sum of angles at Sn of 291.5°. A similarly
narrow angle, was observed for [Kh6(C6H5Me)3-
Sn(CH2-tBu)3] [14] (average CꢀSnꢀC angles of 91.7°),
their structural features are very similar and will be
described together. Fig. 2 depicts the complete structure
of compound 5, while Fig. 3 shows one of the stannide
anions.
Compounds 5 and 6 display separated ions. The
alkaline earth metal cations are surrounded by one
18-crown-6 macrocycle and two HMPA donors, result-
ing in a coordination number of eight. A center of
symmetry at the central metal generates half of the
crown ether atoms in addition to the second HMPA
donor. Consequently, only one [Sn(SnPh3)3]− anion is
contained in each asymmetric unit. Metal–oxygen dis-
tances (crown ether) for 5 range from 2.589(4) to
and
Li(PMDTA)SnPh3
[2a]
(PMDTA=(Me2-
NCH2CH2)2NMe) (average CꢀSnꢀC angles of 96.1°).
This significant pyramidal geometry in the triorganotin
unit, has been explained by a high p-character in the
tin-carbon bond, affected by the differences in energy
between the s and p orbitals [15]. Consequently, the
lone pair, and tinꢀalkali metal bond possesses high
s-character. explaining the similar geometries between
the separated and contact species (Table 1).
,
2.735(4) A, with significantly shorter calcium-oxygen
,
(HMPA) distances (2.243(3) A). Metal-oxygen (crown
ether) interactions for 6 are in the range of 2.668(4)–
2.2.2. [MII(18-crown-6)(HMPA)2][Sn(SnPh3)3]2, 5
(MII=Ca) and, 6 (MII=Sr)
Compounds 5 and 6 are isomorphous. Accordingly,
2.736(4) A, the SrꢀO (HMPA) distances are observed at
,
−
,
2.428(4) A. The [Sn(SnPh3)3] anions exhibit central Sn
atoms with three SnꢀSn linkages, observed between

Table 1
Selected bond lengths (A) and angles (°) in compounds 4–8
,
,
,
,
Compound Sn–Sn (A)
Sn–C (A)
M-donor (A)
Sn–Sn–Sn (°)
C–Sn–C(°)
/
4
2.231(3), 2.233(3), 2.240(2)
2.5674(17) a 2.7703(15) b
2.7785(15) b 2.8097(16) b
2.243(3) a 2.589(4) b 2.665(3) b
95.08(9), 96.20(9), 98.75(9)
5
2.8202(5), 2.8290(5),
2.157(5), 2.160(5), 2.161(5), 2.168(5),
96.456(14)
97.434(14)
98.8(2), 99.0(2), 100.2(2), 100.5(2),
100.7(2), 104.1(2), 105.8(2), 106.7(2),
106.9(2)
2.8347(5)
2.173(5), 2.175(5), 2.176(5), 2.181(5), 2.192(5) 2.735(4) b
96.203(14)
95.71(2),
6
2.8108(8), 2.8301(8),
2.8358(8)
2.137(7), 2.146(7), 2.148(7), 2.158(6),
2.159(7), 2.163(6), 2.166(6), 2.173(7),
2.190(7),
2.141(2), 2.141(3), 2.143(2), 2.145(2),
2.146(3), 2.147(2), 2.147(2), 2.147(3),
2.147(3), 2.148(3), 2.152(2), 2.152(2),
2.152(3), 2.157(2), 2.157(3), 2.163(2),
2.428(4) a, 2.668(4) b 2.688(4) b
2.735(4) b
99.7(2), 101.0(2), 101.2(3), 101.4(2),
98.26(2), 98.30(2) 101.8(2), 103.6(3), 104.5(2), 104.6(3),
105.2(2),
115.522(8),
117.583(7)
7 c
2.7685(2), 2.7719(2), 2.7935
(2), 2.8030(3)
103.94(9), 104.80(10), 105.73(10),
106.05(10), 106.49(9), 106.85(9), 107.44(9),
107.89(10), 108.21(10), 108.70(10),
108.95(10), 109.16(10), 109.55(10),
111.111(10)
613
8
2.7983(6)
2.147(6)
109.5
107.2(2)
(
a HMPA.
b 18-crown-6.
139
c Two independent molecules.
147

U. Englich et al. / Journal of Organometallic Chemistry 613 (2000) 139–147
143
[Sn(SnPh3)3]− anion has been observed previously as
the product of a reaction involving SnPh4 and elemen-
tal lithium in liquid ammonia, resulting in
[Li(NH3)4][Sn(SnPh3)3] [4], or in the reaction of
Ph2SnCl2 with elemental ytterbium, yielding [Yb(-
DME)3Cl]2 [Sn(SnPh3)3]2 [3]. Structural features of the
lithium and ytterbium derivatives and 5 and 6 compare
favorably: SnꢀSn distances in [Li(NH3)4][Sn(SnPh3)3]
are observed between 2.817(1) and 2.834(2), with the
ytterbium derivative displaying very similar values (5
,
2.8202(5) and 2.8347(5) A in 5 and 2.8108(8) and
,
2.8358(8) A in 6. The central Sn atoms exhibit pyrami-
dal geometry with angle sums of 290.1(1) (5) and
292.3(1)° (6).
The cations in compounds 4–6 are very similar: in
both cases the metal is connected to crown ether and
two HMPA donors. The comparison of metal-crown
and metal-HMPA bond lengths shows a smooth trend
consistent with the increase in the ionic radius (ionic
radii CN=8: Ca 1.26 A, Sr 1.40 A, Ba 1.56 A) [16].
This specific cation coordination has been observed
previously in [Sr(18-crown-6)(HMPA)2][SMes*]2 [17],
,
,
,
,
2.8108(8), 6 2.8358(8) A). The SnꢀSn distances may
also be compared with those in the Zintl ion Sn24−. Not
surprisingly, the dianion displays slightly longer SnꢀSn
(Mes*=2,4,6-tBu3C6H2),
[SeMes*]2 [18], and
[Sr(18-crown-6)(HMPA)2]
[Ba(18-crown-6)(HMPA)2]-
,
distances with an average of 2.96 A [20]. The sum of
tinꢀtinꢀtin angles in 5 is 290.09°, and 292.27° for com-
pound 6. These values agree well with the geometry
observed for the tin center in 4, and the closely related
stannide derivatives mentioned above.
[SeMes*]2 [19], where the strong cation-donor interac-
tion affected the cation and anion separation. The
2.2.3. Ph3SnSnPh2SnPh3 (7)
Compound 7, depicted in Fig. 4 crystallizes with two
independent molecules in the asymmetric unit, of which
only one is shown. The central tin backbone consists of
three tin atoms, arranged in a zigzag chain. All tin
centers are four coordinate: the outer ones with three
SnꢀPh and one SnꢀSn contact, the central one with two
SnꢀSn bonds and two SnꢀPh interactions. Tinꢀtin bond
,
lengths are observed between 2.7685(2) and 2.830(3) A,
while tin-carbon distances are found between 2.141(2)
,
and 2.163(2) A. The tin atoms display approximate
tetrahedral geometry with tinꢀtinꢀtin angle of
115.522(8) and 117.583(7)° for the two independent
molecules, carbon–tin–carbon angles between
a
103.94(9) and 111.11(10)°, and carbon-tinꢀtin angles
between 110.59(7) and 115.68(7)°.
Fig. 3. The stannide anion in 5 illustrating the pyramidal geometry at
the central Sn atoms. Anisotropic displacement parameters depict
30% probability. The hydrogen atoms have been omitted for clarity.
2.2.4. Sn(SnPh3)4 (8)
Compound 8, shown in Fig. 5 crystallizes in the cubic
space group P-43n. Only two of the tin atoms, in
addition to one phenyl ring are contained in the asym-
metric unit. The central tin atom is surrounded in an
ideal tetrahedral fashion by four tin atoms, which are
ligated by three phenyl groups, resulting in a tetrahe-
dral geometry for all tin atoms. The tinꢀtin distance is
,
observed at 2.7983(6) A and the tin-carbon distances
,
are observed at 2.147(6) A.
2.3. Conclusion
This work was conducted to explore the chemistry of
the heavy alkaline earth elements calcium, strontium,
and barium in conjunction with stannide anions. Syn-
thetic access to the target molecules was possible by
reductive insertion, involving the reaction of the metals
with hexaphenyldistannane in liquid ammonia. The ma-
jor reaction products of these reactions were identified
Fig. 4. Crystal structure of 7 with anisotropic displacement parame-
ters depicting 30% probability. The hydrogen atoms have been omit-
ted for clarity. Only one of the two independent molecules is shown.

144
U. Englich et al. / Journal of Organometallic Chemistry 613 (2000) 139–147
the extreme sensitivity of the alkaline earth metal stan-
nides towards hydrolysis. For example, typical working
time for mounting crystals was less than 10 min before
decomposition occurred, even while the crystals were
stored under a heavy hydrocarbon oil.
3.2. General procedure for the synthesis of the alkaline
earth metal stannides 2–6
The synthetic procedures for compounds 4, 5 and 6
were very similar. In the dry box Schlenk tubes were
charged with either 0.3 g Ca (7.5 mmol), 0.3 g Sr (3.4
mmol) or 0.4 g Ba (3.0 mmol) and 0.7 g (SnPh3)2 (1
mmol). To these solids, 50 ml THF was added. The
resulting mixtures were cooled to −78°C utilizing an
acetone/dry-ice bath, whereupon approximately 10 ml
of pre-dried liquid ammonia was condensed onto the
reaction mixtures. The mixtures were refluxed for 6 h at
−33°C (boiling point ammonia), where upon the initial
blue color of the solution (unreacted metal in liquid
NH3), changed into a light gray, and then into reddish
brown. After 6 h the solutions were gently warmed to
room temperature upon which the ammonia evapo-
rated. The remaining solvents were removed in vacuum,
and the resulting light gray powder dissolved in a
solution consisting of 60 ml dimethoxyethane (DME),
0.26 g 18-crown-6 (1.5 mmol) and 5 ml HMPA. The
resulting solution was heated to a boil, and filtered hot
through a Celite padded filter frit, resulting in a clear,
pale green solution.
Fig. 5. Crystal structure of 8 with anisotropic displacement parame-
ters depicting 30% probability. The hydrogen atoms have been omit-
ted for clarity.
as M(SnPh3)2, by quenching the reaction mixture with
anhydrous HCl and utilizing 119Sn-NMR spectroscopy.
Crystalline samples obtained after the addition of 18-
crown-6 and HMPA indicated that phenyl migration
had taking place, under formation of the more complex
anions Sn(SnPh3)3 in addition to SnPh4.
3. Experimental
3.1. General procedures
3.2.1. Isolation of 4, 5 and 6
All reactions were performed under a purified nitro-
gen atmosphere by using modified Schlenk techniques
and a Braun Labmaster 100 dry box. Toluene, DME,
THF, and Et2O were distilled just prior to use from a
Na/K alloy followed by two freeze-pump-thaw cycles.
Anhydrous ammonia (Matheson) was predried over
sodium and condensed into the cooled (−78°C, dry
ice/acetone) reaction mixtures. Commercially available
strontium and barium metals were stored under mineral
oil in a dry box, cut into small chunks and the remain-
ing hydrocarbon oil was washed off with dry hexane.
Calcium chips were used as received. Hexaphenyldis-
tannane was prepared by published procedures [21].
HMPA was stirred over CaH2 and distilled prior to use.
Commercially available 18-crown-6 was dissolved in
freshly distilled diethylether and stirred with finely cut
sodium metal for one day. After filtration from excess
metal, the crown was recrystallized at −20°C from
After storage of the solutions for a few days at
−20°C colorless crystals, suitable for X-ray crystallog-
1
raphy formed. H-NMR for 4 (300.13 MHz, l [ppm]):
2.60 (d, 36 H3, JPH=9.1 Hz), 3.58 (24 H), 6.85 (dd, 12
H), 6.98 (t, 6 H), 7.21 (d, 12 H1, JSn-H=40/38 Hz).
119Sn-NMR for 4 (111.90 MHz, l [ppm]): −98.4.
1H-NMR for 5 (300.13 MHz, l [ppm]): 2.59 (d, 36 H3,
J
PH=9.2 Hz), 3.48 (24 H), 7.02 (dd, 12 H), 7.49 (t, 6
1
H), 7.25 (d, 12 H1, JSn-H=40/38 Hz). H-NMR for 6
(300.13 MHz, l [ppm]): 2.65 (d, 36 H3, JPH=9.5 Hz),
3.56 (24 H), 6.86 (dd, 12 H), 6.99 (t, 6 H), 7.21 (d, 12
H1, JSn-H=41/39 Hz).
Due to the very low solubility of 5 and 6 no 119Sn-
NMR data are available. Reliable elemental analyses
could not be obtained, even when glove-box handling
was attempted, due to the high moisture and oxygen
sensitivity of all compounds reported. This is a well
known problem in alkaline earth metal chemistry [22].
1
hexanes and used as isolated. H-(300 MHz) and 13C
(75 MHz)-NMR were recorded on a Bruker DPX-300
spectrometer. 119Sn-(149.19 MHz) and 29Si-NMR data
(79.49 MHz) were collected using Bruker DRX 300 and
DPX 400 spectrometers. Elemental analyses were ob-
tained only for the non-metalated compounds, due to
3.2.2. Reaction with HCl
The reactions described above were repeated, as de-
scribed above, but after evaporation of the NH3 at
room temperature, the solution was quenched with 5 ml
of a 1N HCl solution in diethylether, followed by

U. Englich et al. / Journal of Organometallic Chemistry 613 (2000) 139–147
145
Table 2
Crystallographic data for compounds 4–8 a
Compound
4
5
6
7
8
Empirical formula
Formula weight
Crystal shape
C60H90BaN6O8P2Sn2
1460.04
Colorless plate
0.68×0.40×0.10
14.2205(2)
C132H150CaN6O8P2Sn8
3000.12
C132H150N6O8P2Sn8Sr
3047.66
C96H80Sn6
1945.74
Colorless block
0.70×0.64×0.50
10.2373(1)
19.6400(1)
22.0183(3)
76.389(1)
79.238(1)
74.988(1)
4118.37(7)
2
C90H96Sn5
1771.12
Colorless cube
0.50×0.50×0.50
15.5070(1)
Colorless plate
0.45×0.20×0.05
14.6442(5)
14.8981(5)
15.3800(6)
98.589(1)
100.570(1)
94.254(1)
3243.7(2)
1
Colorless plate
0.30×0.20×0.05
14.675(2)
14.755(2)
16.000(3)
107.516(3)
98.427(4)
95.716(3)
3229.9(9)
1
Crystal size (mm)
,
a (A)
,
b (A)0
10.8190(1)
22.3361(2)
,
c (A)
h (°)
i (°)
98.175(1)
k (°)
3
,
V (A )
Z
3401.52(6)
2
3728.92(4)
2
Space group
P21/n
1.426
1.400
Mo–Ka
150
P1
1.536
1.633
Mo–Ka
P1
1.567
2.009
Mo–Ka
P1
1.569
1.836
Mo–Ka
150
P-43n
1.577
1.697
Mo–Ka
150
Dcalc (g cm−3
)
Lin. abs. coeff. (mm−1
Radiation
T (K)
)
150
150
2q Range (°)
3–57
3–57
3–57
2–57
3–57
Independent reflections
8050 (0.0143)
14453 (0.0394)
14274 (0.0559)
18346 (0.0153)
1548 (0.0268)
(Rint
)
Parameters
359
736
710
920
66
R1, wR2 (all data)
R1, wR2 (\2|)
0.0307, 0.0682
0.0278, 0.0668
0.0800, 0.1118
0.0482, 0.0995
0.1242, 0.1019
0.0678, 0.0877
0.0340, 0.0557
0.0257, 0.0521
0.0540, 0.1055
0.0476, 0.1016
2
2
a R1=SꢀꢀFoꢀ−ꢀFcꢀꢀ/SꢀFoꢀ, wR2=ꢁSw{(Fo)2−(Fc)2}2/Sw{(Fo)2}2, R=SꢀꢀFoꢀ−ꢀFcꢀꢀ/SꢀFoꢀ, wR=ꢁSwꢀꢀFoꢀ−ꢀFcꢀꢀ /SꢀFoꢀ .
removal of the volatiles in vacuum. The resulting solids
were dissolved in diethylether, and filtered with the aid
of a Celite padded filter frit, resulting in a clear pale
yellow solution. The diethylether was removed, and the
remaining solids examined by 119Sn-NMR spec-
troscopy. 119Sn-NMR (ppm): Ph3SnCl (ꢀ70%,−48.5
ppm), Ph3SnSnPh3 (25%,−144.1 ppm), Ph4Sn (ꢀ2–
3%, −128.4 ppm) and small unidentified signals at−
132.5 and 138.4 ppm.
3.4. Sn(SnPh3)4 (8)
Compound 8 can be synthesized in pure form by
adding a solution containing 0.019 g Ph3SnCl (0.05
mmol) dissolved in 25 ml THF dropwise to a cooled
solution (−60°C) of 0.15 g of 5 (0.05 mmol) in 50 ml
THF. The reaction mixture was stirred for 4 h and then
allowed to warm to room temperature. The solvent was
removed in vacuum and 100 ml of diethylether/n-hex-
ane (1:1) were added. The mixture was filtered (G3) and
the solvent removed in vacuum. The resulting solid
residue was recrystallized from a 1:1 mixture of toluene
and diethylether. 8: M.p. 302–308°C. Elemental analy-
sis: Anal. Found (calc.) C 57.7(56.9) H 4.25(3.98).
119Sn-NMR: −135.51 ppm (SnPh3);−1092.4 ppm
(Sn).
3.3. Ph3SnꢀSnPh2ꢀSnPh3 (7)
A solution comprised of 0.086 g Ph2SnCl2 (0.25
mmol) in 25 ml THF was added dropwise to a cooled
solution (−60°C) of 0.37 g of 4 (0.25 mmol) dissolved
in 50 ml THF. The resulting mixture was stirred for 4
h and then gently warmed to room temperature. The
solvent was removed in vacuum and 100 ml of di-
ethylether/n-hexane (1:1) were added. The mixture was
filtered (G3) followed by removal of the solvent in
vacuum. Colorless crystals were obtained from a 1:1
mixture of toluene and diethylether after storage for a
few days at −20°C. The colorless crystals are com-
posed of a mixture of 7 and 8, accordingly, no sharp
melting point is observed (range 140–180°C). Com-
pounds 7 and 8 can be manually separated under the
microscope. 7: M.p. 208–212°C. Elemental analysis:
Anal. Found (calc.) C 60.1(59.3) H 3.95(4.18) 119Sn-
3.5. X-ray crystallographic studies
X-ray quality crystals for all compounds were grown
as described in the experimental section. The crystals
were removed from the Schlenk tube under a stream of
N2 and immediately covered with a layer of viscous
hydrocarbon oil (Paratone N, Exxon). A suitable crys-
tal was selected with the aid of a microscope, attached
to a glass fiber, and immediately placed in the low
temperature N2 stream of the diffractometer [23]. Inten-
sity data sets for all compounds were collected utilizing
a Siemens SMART system, complete with 3-circle go-
NMR: −138.1 ppm (SnPh3);−230.7 ppm (SnPh2);
2
1J119
=2875/2745 cps; J119
=705 cps.
117
Snꢀ
Sn
119/117
Snꢀ
Sn

146
U. Englich et al. / Journal of Organometallic Chemistry 613 (2000) 139–147
niometer and CCD detector operating at −54°C. Each
data set was collected at −123°C using a Cryojet low
temperature device from Oxford Instruments and by
employing graphite monochromated Mo-Ka radiation
grateful to the Deutsche Forschungsgemeinschaft
(UH74/3), the Degussa-Huels AG (Germany) and Pro-
fessor Dr K. Jurkschat (Universita¨t Dortmund) for
support of this work.
,
(u=0.71073 A). The data collections nominally cov-
ered a hemisphere of reciprocal space utilizing a combi-
nation of three groups of exposures, each with a
different angle and each exposure covering 0.3° in ꢀ.
Crystal decay was monitored by repeating a set of
initial frames at the end of the data collection and
comparing the duplicate reflections, whereby no decay
was observed for all compounds reported. An absorp-
tion correction was applied utilizing the program SAD-
ABS [24]. The crystal structures of all compounds were
solved by Direct Methods, as included in the SHELXTL
program package [25]. Missing atoms were located in
subsequent difference Fourier maps and included in the
refinement. The structures were refined by full-matrix
References
[1] J.P. Quintard, M. Pere`yre, Reviews on Silicon, Germanium, Tin
and Lead Compounds IV (1980) 153.
[2] Examples of crystal structures of alkali metal stannides with
tinꢀaryl bonds: (a) D. Reed, D. Stalke, D.S. Wright, Angew.
Chem. Int. Ed. Engl. 30 (1991) 1459. (b) T. Birchall, J.A.
Ventrone, J. Chem. Soc., Chem. Commun. 77 (1988). (c) M.G.
Davidson, D. Stalke, D.S. Wright, Angew. Chem. Int. Ed. Engl.
31 (1992) 1226. (d) D.R. Armstrong, M.J. Duer, D. Moncrief,
C.A. Russell, C. Stourton, A. Steiner, M.G. Davidson, D.
Stalke, D.S. Wright, Organometallics 16 (1997) 3340. (e) M.M.
Olmstaed, R.S. Simons, P.P. Power, J. Am. Chem. Soc. 119
(1997) 11705. (f) M.A. Paver, C.A. Russell, D. Stalke, J. Chem.
Soc. Chem. Comm. (1993) 1349. (g) M.A. Beswick, C.J. Belle,
M.K. Davies, M.A. Halcrow, P.R. Raithby, A. Steiner, D.S.
Wright, J. Chem. Soc. Chem. Comm. (1996) 2619. (h) H. Scotti,
U. Zachwieja, H. Jacobs, Z. Anorg. Allg. Chem. 623 (1997)
1503. (i) G.D. Smith, P.E. Fanwick, I.P. Rothwell, Acta Cryst.
C51 (1995) 2501. (k) T. Kawashima, N. Iwama, R. Okazaki, J.
Am. Chem. Soc. 115 (1993) 2507.
least-squares refinement on F2
(SHELXTL-93) [25]. Hy-
drogen atoms were placed geometrically and refined
using a riding model, including free rotation of methyl
groups. All compounds were refined with Uiso con-
strained at 1.2 (for non-methyl groups), and 1.5 (for
methyl groups) times Ueq of the carrier C atom. The
crystallographic programs used for structure refinement
and solution were installed on a PC clone or a Silicon
Graphics Indigo2 R10000 High Impact. Scattering fac-
tors were those provided by the SHELX program [26].
All non-hydrogen atoms, with the exception of some
disordered or restrained positions were refined an-
isotropically Table 2.
[3] L.N. Bochkarev, D.V. Grochev, S.F. Ziltsov, L.N. Zakharov,
Y.T. Struchkov, J. Organomet. Chem. 436 (1992) 299.
[4] F. Flacke, H. Jacobs, Eur. J. Solid State Inorg. Chem. 34 (1997)
495.
[5] (a) C. Tamborski, E.J. Sokolowski, J. Am. Chem. Soc. 83 (1961)
3734. (b) H.J.M.C. Creemers, J.G. Noltes, G.J.M. van der Kerk,
J. Organomet. Chem. 14 (1968) 217. (c) J.-C. Lahournere, J.
Verkade, J. Organomet. Chem. C3 (1970) 22. (d) B. Jousseaume,
N. Noiret, M. Pereyre, A. Saux, Organometallics 13 (1994) 1034.
[6] (a) R. Hummeltenberg, K. Jurkschat, F. Uhlig, Phosphorus,
Sulfur Silicon 123 (1997) 255. (b) C. Kayser, R. Klassen, M.
Schu¨rmann, F. Uhlig, J. Organomet. Chem. 556 (1998) 165. (c)
F. Uhlig, C. Kayser, R. Klassen, U. Hermann, L. Brecker, M.
Schu¨rmann, K. Ruhlandt-Senge, U. Englich, Z. Naturforsch.
54b (1999) 278. (d) U. Hermann, M. Schu¨rmann, F. Uhlig, J.
Organomet. Chem. 585 (1999) 211.
[7] M. Westerhausen, Angew. Chem. Int. Ed. Engl. 33 (1994) 14.
[8] S. Oda, K. Hisatani, Jpn. Kokai Tokkyo Koho JP 0368.606
1991, Chem. Abstr. 1991 115 233143g.
[9] (a) M. Pereyre, J.P. Quintard, A. Rahm, Tin in Organic Synthe-
sis, Butterworths, London, 1987. (b) I. Omae, Organotin chem-
istry, Elsevier, Amsterdam, 1989. (c) Y. Yamamoto (Ed.),
Organotin Compounds in Organic Synthesis, Tetrahedron 45
(1989) 909. (d) P.G. Harrison, Chemistry of Tin, Blackie, Glas-
gow, 1989.
4. Supplementary material
Crystallographic data for the structural analysis have
been deposited with the Cambridge Crystallographic
Data Centre, CCDC No. 137 003 for compound 4, No.
137 004 for compound 5, No. 137 005 for compound 6,
No. 137 006 for compound 7, and No. 137 007 for
compound 8. Copies of this information may be ob-
tained free of charge from: The Director, CCDC, 12
Union Road, Cambridge CB2 1EZ, UK (Fax: +44-
1223-336-033; e-mail: deposit@ccdc.cam.ac.uk or www:
http://www.ccdc.cam.ac.uk).
[10] (a) W.L. Wells, T.L. Brown, J. Organomet. Chem. 11 (1968) 271.
(b) K. Kobayashi, M. Kawanisi, T. Hitomi, S. Kozima, J.
Organomet. Chem. 233 (1982) 299.
[11] D.R. Armstrong, M.G. Davisson, D. Mongrief, D. Stalke, D.S.
Wright, J. Chem. Soc. Chem. Comm. (1992) 1413.
Acknowledgements
[12] W. Neumann, Angew. Chem. 87 (1975) 844.
This work was supported by Syracuse University
(KRS), the National Science Foundation (KRS; CHE-
9702246), and the Deutsche Forschungsgemeinschaft
(Postdoctoral stipend for U.E.). Purchase of the X-ray
diffractometer at Syracuse University was made possi-
ble with grants from NSF (CHE-95-27898), the W.M.
Keck Foundation and Syracuse University. F.U. is
[13] H. Gilman, F.K. Cartledge, J. Organomet. Chem. 5 (1966) 48.
[14] P.B. Hitchcock, M.F. Lappert, G.A. Lawless, B. Royo, J. Chem.
Soc. Chem. Comm. (1993) 554.
[15] M.A. Paver, C.A. Russell, D.S. Wright, Angew. Chem. Int. Ed.
Engl. 34 (1995) 1545.
[16] R.D. Shannon, Acta Cryst. A32 (1976) 751.
[17] S. Chadwick, U. Englich, K. Ruhlandt-Senge, Chem. Commun.
(1998) 2149.

U. Englich et al. / Journal of Organometallic Chemistry 613 (2000) 139–147
147
[18] U. Englich, K. Ruhlandt-Senge, unpublished.
[19] U. Englich, K. Ruhlandt-Senge, Chemistry, A European Jour-
nal, in press.
[20] S.C. Critchlow, J.D. Corbett, J. Chem. Soc. Chem. Comm.
(1981) 236.
[21] K. Krause, G. Becker, Chem. Ber. 53 (1920) 180.
[22] M.L. Hays, T.P. Hanusa, T.A. Nile, J. Organomet. Chem. 73
(1996) 514 and references therein.
[23] H. Hope, Progr. Inorg. Chem. 41 (1994) 1.
[24] G.M. Sheldrick, SADABS, Program for Absorption Correction
Using Area Detector Data, University of Go¨ttingen, Germany,
1996.
[25] G.M. Sheldrick, SHELXL-93, Program for Crystal Structure
Refinement, University of Go¨ttingen, Go¨ttingen Germany, 1993.
[26] Siemens SHELXTL Plus, Program Packet for Structure Solution
and Refinement, Siemens, Madison, Wisconsin, 1996.
.