Self-assembly using stannylplatinum(IV) halide complexes as ligands for organotin halides

Article abstract of DOI:10.1139/v02-093

The possibility of forming extended structures by self-association using transition metal halides as donors to organotin acceptors has been investigated. The stannylplatinum(IV) complex [PtClMe₂(SnMe₂Cl)(bu₂bpy)] forms a 1:1 adduct [PtClMe₂(SnMe₂Cl)(bu₂bpy)]·Me ₂SnCl₂ with Me₂SnCl₂ in which the organoplatinum complex acts as a donor to the organotin halide. Similarly, [PtClMe₂(SnMeCl₂)(bu₂bpy)] forms adducts [PtClMe₂(SnMeCl₂)(bu₂bpy)]·MeSnCl ₃ or [PtClMe₂(SnMeCl₂)(bu₂bpy)]·Me ₂SnCl₂, and [{PtClMe₂(bu₂bpy)}₂(μ-SnCl₂)] forms [{PtClMe₂(bu₂bpy)}₂(μ-SnCl₂)] ·Me₂SnCl₂. Structure determinations on selected compounds show that the donor is the Pt-Cl group and the acceptor tin centre is 5-coordinate. In the similar bromo complex [PtBrMe₂(SnMeBr₂)(bu₂bpy)]·Me ₂SnBr₂ both the Pt-Br and PtSn-Br groups coordinate to the Me₂SnBr₂ acceptor with short (3.14 or 3.29 A) and long (3.99 or 4.05 A) contacts, respectively, so that the acceptor tin centre adopts distorted octahedral stereochemistry in the solid state and a folded polymeric structure is formed. Reaction of [{PtClMe₂(bu₂bpy)}₂(μ-SnCl₂)] with AgO₃SCF₃ yields the complex [{PtClMe₂(bu₂bpy)}(μ-SnCl₂){PtMe ₂(bu₂bpy)O₃SCF₃}], which is fluxional in solution.

Full text of DOI:10.1139/v02-093

1451
Self-assembly using stannylplatinum(IV) halide
complexes as ligands for organotin halides
Michael C. Janzen, Michael C. Jennings, and Richard J. Puddephatt
Abstract: The possibility of forming extended structures by self-association using transition metal halides as donors to
organotin acceptors has been investigated. The stannylplatinum(IV) complex [PtClMe2(SnMe2Cl)(bu2bpy)] forms a 1:1
adduct [PtClMe2(SnMe2Cl)(bu2bpy)]·Me2SnCl2 with Me2SnCl2 in which the organoplatinum complex acts as a donor to
the organotin halide. Similarly, [PtClMe2(SnMeCl2)(bu2bpy)] forms adducts [PtClMe2(SnMeCl2)(bu2bpy)]·MeSnCl3 or
[PtClMe2(SnMeCl2)(bu2bpy)]·Me2SnCl2, and [{PtClMe2(bu2bpy)}2( -SnCl2)] forms [{PtClMe2(bu2bpy)}2( -
SnCl2)]·Me2SnCl2. Structure determinations on selected compounds show that the donor is the Pt-Cl group and the ac-
ceptor tin centre is 5-coordinate. In the similar bromo complex [PtBrMe2(SnMeBr2)(bu2bpy)]·Me2SnBr2 both the Pt-Br
and PtSn-Br groups coordinate to the Me2SnBr2 acceptor with short (3.14 or 3.29 Å) and long (3.99 or 4.05 Å) con-
tacts, respectively, so that the acceptor tin centre adopts distorted octahedral stereochemistry in the solid state and a
folded polymeric structure is formed. Reaction of [{PtClMe2(bu2bpy)}2( -SnCl2)] with AgO3SCF3 yields the complex
[{PtClMe2(bu2bpy)}( -SnCl2){PtMe2(bu2bpy)O3SCF3}], which is fluxional in solution.
Key words: platinum, tin, self-assembly, coordination chemistry, organometallics.
Résumé : On a étudié la possibilité de former des structures étendues par autoassociation en utilisant des halogénures
de métaux de transition comme donneurs à des composés organostanniques agissant comme accepteurs. Le complexe
stannylplatine(IV) [PtClMe2(SnMe2Cl)(bu2bpy)] et le Me2SnCl2 forment un adduit 1:1 [PtClMe2(SnMe2Cl)(bu2bpy)]·Me2SnCl2
dans le complexe organoplatine agit comme donneur pour l’halogénure d’organoétain. De la même manière,
[PtClMe2(SnMeCl2)(bu2bpy)] forme les adduits [PtClMe2(SnMeCl2)(bu2bpy)]·MeSnCl3 ou [PtClMe2(SnMeCl2)-
(bu2bpy)]·Me2SnCl2 alors que [{PtClMe2(bu2bpy)}2( -SnCl2)] forme [{PtClMe2(bu2bpy)}2( -SnCl2)]·Me2SnCl2. Des
déterminations de structure effectuées sur des composés choisis montrent que le donneur est le groupe Pt-Cl et que le
centre étain accepteur est pentacoordiné. Dans le complexe bromé semblable [PtBrMe2(SnMeBr2)(bu2bpy)]·Me2SnBr2
les deux groupes Pt-Br et PtSn-Br se coordonnent à l’accepteur Me2SnBr2 avec des contacts respectivement courts
(3,14 ou 3,29 Å) et longs (3,99 ou 4,05 Å) qui font que le centre étain accepteur adopte une stéréochimie octaédrique
déformée à l’état solide et qu’il y a formation d’une structure polymérique repliée. La réaction du
[{PtClMe2(bu2bpy)}2( -SnCl2)] avec le AgO3SCF3 conduit à la formation du complexe [{PtClMe2(bu2bpy)}2( -
SnCl2){PtMe2(bu2bpy)O3SCF3}] qui, en solution, est en état de fluxion.
Mots clés : platine, étain, autoassemblage, chimie de coordination, organométalliques.
[Traduit par la Rédaction] Janzen et al. 1457
Introduction
Scheme 1 (8). It was argued that the Pt-I group trans to
Me3Sn is polarized Ptꢀ+-Iꢀ–, and as a result the iodide is a
strong enough donor to form a complex with the weak ac-
ceptor Me3SnI (9, 10). The platinum complex thus acts as a
ligand for Me3SnI through the Pt-I group.
The oxidative addition of the tin–halogen bond in organo-
tin(IV) halides to transition-metal complexes is well estab-
lished and provides an easy synthesis of stannylplatinum(IV)
halides (1–7). For example, the oxidative addition of Me3SnI
to [PtMe2(bu2bpy)] (1) (bu2bpy = 4,4>-di-tert-butyl-2,2>-
bipyridine) gives [PtIMe2(Me3Sn)(bu2bpy)] (1), which forms
a complex [PtIMe2(SnMe3)(bu2bpy)]·Me3SnI by coordina-
tion of the Pt-I donor to the Me3SnI acceptor, as shown in
Trimethyltin iodide is a tetrahedral monomer in the solid
state, but many other organotin halides undergo self-
association in the solid state (9–11). For example, Me2SnCl2
self-associates to form one-dimensional chains (Sn—Cl =
2.40(4) Å, Sn···Cl = 3.54(5) Å), and MeSnCl3 also under-
goes association by weak bridging through two of the three
chlorine atoms (Sn—Cl = 2.283(2) Å, 2.318(1) Å; Sn···Cl =
3.714(2) Å) as illustrated in Chart 1 below (12, 13). The
dimethyltin dihalides can also form adducts with one or two
halide ions in which the tin centres adopt distorted trigonal
bipyramidal or octahedral stereochemistry, respectively
(Chart 1); they are stronger acceptors than the trimethyltin
halides (14).
Received 20 January 2002. Published on the NRC Research
Press Web site at http://canjchem.nrc.ca on 30 October 2002.
Dedicated to Professor Tris Chivers for his contributions to
Canadian chemistry.
M.C. Janzen, M.C. Jennings, and R.J. Puddephatt.1
Department of Chemistry, The University of Western Ontario,
London, ON N6A 5B7, Canada.
Based on the structures shown in Scheme 1 and Chart 1, it
was considered possible that association between stannyl-
1Corresponding author (e-mail: pudd@uwo.ca).
Can. J. Chem. 80: 1451–1457 (2002)
DOI: 10.1139/V02-093
© 2002 NRC Canada

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Can. J. Chem. Vol. 80, 2002
Scheme 1. S = solvent.
Scheme 2. NN = bu2bpy.
Scheme 3. NN = bu2bpy.
platinum(IV) complexes and excess Me2SnX2 (X= Cl, Br) or
MeSnCl3 could lead to new forms of supramolecular associ-
ation through Pt-X···Sn and (or) PtSnX···Sn secondary bond-
ing, and this paper reports the results of a systematic study
of such systems.
Scheme 4. NN = bu2bpy.
Results and discussion
potential 1:2 complex [( -SnCl2){PtClMe2(bu2bpy)}2]·2Me2-
SnCl2.
Synthesis of the complexes
The reaction of complex 1 with Me2SnX2 gave the corre-
In each case the adduct formation was reversible and the
complexes existed in solution mainly in dissociated form at
1
sponding
products
of
trans
oxidative
addition
room temperature. For example, the H NMR spectrum of
[PtXMe2(SnMe2X)(bu2bpy)] (2a: X = Cl, 2b: X = Br), and
crystallization in the presence of excess Me2SnX2 allowed
isolation of the corresponding complexes [PtXMe2(SnMe2X)-
(bu2bpy)]·Me2SnX2 (3a: X = Cl, 3b:, X = Br) (Scheme 2).
Similarly, reaction of 1 with MeSnCl3 gave [PtClMe2-
(SnMeCl2)(bu2bpy)] (4), which could be crystallized with ei-
ther MeSnCl3 or Me2SnCl2 to give the complexes
[PtClMe2(SnMeCl2)(bu2bpy)]·MeSnCl3 (5) or [PtClMe2-
(SnMeCl2)(bu2bpy)]·Me2SnCl2 (6), respectively (Scheme 3).
It was not possible to crystallize 2a with MeSnCl3, since a
reaction occurred to give 4 with displacement of Me2SnCl2
from platinum.
In a similar way, crystallization of the -stannylene com-
plex [( -SnCl2){PtClMe2(bu2bpy)}2] (7) (2) with excess
Me2SnCl2 yielded air-stable, colorless crystals of the com-
plex [( -SnCl2){PtClMe2(bu2bpy)}2]·Me2SnCl2 (8), as shown
in Scheme 4. Although complex 7 contains two Pt-Cl groups
that could act as ligands, it was not possible to crystallize a
3a at room temperature contained peaks assigned to the
complex 2a and free Me2SnCl2 (ꢀ(MeSn) = 1.14, J(SnMe) =
2
69 Hx) only, indicating effectively complete dissociation in
solution. However, at lower temperatures there is an increase
2
in the magnitude of the coupling constant J(SnMe) for the
Me2SnCl2 resonance (75 Hz at –2°C, 80 Hz at –67°C) indi-
cating reversible coordination to the Me2SnCl2 that is more
favorable at lower temperatures (8). At no temperature were
separate signals for free and complexed Me2SnCl2 observed,
indicating that exchange between free and complexed forms
was rapid and making it difficult to determine the associa-
tion constant. The adducts clearly must be characterized in
the solid state by X-ray structure determinations, since the
easy exchange, involving reversible addition of Me2SnCl2,
makes solution characterization difficult.
One extreme formulation of the adducts is as complexes
–
of 16-electron platinum(IV) complexes (15) with [SnMexX5–x
]
anions, and we have attempted to isolate further examples of
© 2002 NRC Canada

Janzen et al.
1453
Scheme 5. NN = bu2bpy.
Fig. 1. A view of the structure of complex 5.
the 16-electron complexes. In one case, a pure compound
was isolated, but it could not be crystallized for structural
characterization. Thus reaction of 7 with 1 equiv of silver
triflate gave the corresponding triflate derivative [( -
SnCl2){PtClMe2(bu2bpy)}{Pt(O3SCF3)Me2(bu2bpy)}] (9)
1
(Scheme 5). The H NMR spectrum of 9 at room tempera-
ture contained only three aromatic bu2bpy peaks, one tert-
butyl peak, and one Pt-Me resonance. All peaks were broad,
indicating fluxionality such that the two platinum centres be-
come effectively equivalent through chloride for triflate ex-
Fig. 2. A view of the structure of complex 6.
1
change. At –80°C the H NMR spectrum is very complex,
indicating the presence of several complexes in equilibrium.
In the solid state, the structure could be as shown in
Scheme 5 but it could also be polymeric with intermolecular
PtCl···Pt coordination and free triflate ions. The exchange in
solution indicates very easy dissociation of triflate is possi-
ble, with subsequent chloride exchange giving effective two-
fold symmetry.
Structural chemistry
Complexes 5, 6, and 8 exist in the solid state as 1:1 com-
plexes, as shown in Figs. 1–3, and relevant bond parameters
are listed in Table 1. In each case, the chloride atom of the
Pt-Cl group acts as a donor to the acceptor MeSnCl3 in 5 or
Me2SnCl2 in 6 or 8, so that the organotin chloride has
distorted trigonal bipyramidal stereochemistry. These struc-
tures therefore complement that found previously for a
trimethyltin halide acceptor in [PtIMe2(Me3Sn)-
(bu2bpy)]·Me3SnI (Scheme 1) (8). The Pt—Sn bond lengths
appear not to be greatly affected by adduct formation. For ex-
ample, the Pt—Sn distances in complex 8 (2.5561(6) and
2.5479(6) Å) are similar to those in the parent complex 7
(2.5451(5) and 2.5386(6) Å),2 and the distances in com-
plexes 5 (2.5055(5) Å) and 6 (2.5011(6) Å) are similar to
that in [PtClMe2(SnCl2Ph)(bu2bpy)] (2.5186(6) Å) (2). They
also fall in the range reported for other Pt—Sn bonded com-
pounds (2.34–2.80 Å) (7).
The main point of interest is the nature of the bridging
chloride in the adducts. There are two extreme formulations
possible, namely as 18-electron platinum complexes with
weak Pt-X···Sn bonding or as weak complexes between a
2 Supplementary data (tables of X-ray data for the complexes) may be purchased from the Depository of Unpublished Data, Document Deliv-
ery, CISTI, National Research Council Canada, Ottawa, ON K1A 0S2, Canada (http://www.nrc.ca/cisti/irm/unpub_e.shtml for information
on ordering electronically). CCDC 185200–185203 inclusive contain the supplementary data for this paper. These data can be obtained, free
of charge, via www.ccdc.cam.ac.uk/conts/retrieving.html (or from the Cambridge Crystallographic Data Centre, 12 Union Road, Cam-
bridge, U.K.; fax +44 1223 336033; or deposit@ccdc.cam.ac.uk).
© 2002 NRC Canada

1454
Can. J. Chem. Vol. 80, 2002
Fig. 3. A view of the structure of complex 8.
Table 1. Selected bond distances (Å) and angles (°) for com-
plexes 5, 6, and 8.
Complex
Pt—X
5
6
8·pentane
2.510(2)
2.480(2)
2.524(2)
2.466(2)
2.5561(6)
2.5479(6)
2.386(2)
2.384(2)
Pt—Sn
Sn—X
2.5011(6)
2.5055(5)
2.366(2)
2.357(2)
2.111(7)
2.365(3)
2.319(3)
2.311(3)
2.098(9)
2.359(2)
2.352(2)
2.099(6)
2.428(2)
2.342(2)
Sn—C
Sn—X
2.457(3)
2.313(7)
Sn—C
Sn···X
2.109(6)
2.096(5)
3.04
2.14(2)
2.14(1)
2.870(3)
2.813(2)
Pt-X···Sn
132
130
129.0(1)
C-Sn-X
105.3(3)
103.1(3)
102.35(8)
105.6(2)
103.7(2)
100.60(9)
133.9(3)
111.3(2)
108.8(2)
99.4(2)
97.7(2)
X-Sn-X
C-Sn-C
C-Sn-Xe
97.1(1)
126(1)
122.1(5)
110.5(8)
95.2(4)
90(1)
125.9(3)
123.4(4)
97.1(3)
C-Sn-Xa
16-electron platinum(IV) cation and the anionic tin halide
complex [Me2SnCl3]– or [MeSnCl4]–. The first true 16-
electron platinum(IV) complexes have been isolated recently
(15). This issue is most readily addressed for complex 8,
since it contains Pt-Cl groups involved and not involved in
coordination to tin, and axial Sn-Cl groups involved and not
involved in coordination to platinum. The differences in
bond lengths are d[Pt(2)Cl(2)] – d[Pt(1)Cl(1)] = 2.524(2) –
2.466(2) = 0.058 Å and d[Sn(4)Cl(2)] – d[Sn(4)Cl(6)] =
2.870(3) – 2.457(3) = 0.413 Å. It is clear that the formula-
tion as 18-electron platinum complexes with weak Pt-X···Sn
bonding is the correct one, based on this structural criterion,
and it is also consistent with the solution properties dis-
cussed above. The Pt-Cl···Sn angles for the complexes fall in
the narrow range 129–132° (Table 1).
X-Sn-Xe
X-Sn-Xa
X···Sn-C
106.6(1)
97.1(2)
83.3(3)
96.61(6)
83
78
177
86
95.5(4)
87.2(4)
86(1)
175.90(9)
86.0(4)
X···Sn-Xa
X···Sn-Xe
177.3(2)
84.83(9)
81.7(1)
Note: Italicized Sn refers to the coordinated organotin compound, e =
equatorial, a = axial.
with axial Cl···Sn-Cl and equatorial SnMe2Cl groups. The
equatorial substituents are also displaced away from the ter-
minal axial chloride and toward the more weakly bonding
The stereochemistry of the Cl···SnMeCl3 unit of complex
5 is distorted trigonal bipyramidal with axial Cl.Sn-Cl and
equatorial SnMeCl2 groups. The equatorial substituents are
displaced towards Cl(1) and away from Cl(43), as indicated
by the angles Cl(1)Sn(41)C(42), Cl(1)Sn(41)Cl(44),
Cl(1)Sn(41)Cl(45) = 83.3(3), 81.7(1), 84.8(1)° and
Cl(43)Sn(41)C(42), Cl(43)Sn(41)Cl(44), Cl(43)Sn(41)Cl(45) =
97.1(3), 95.9(2), 97.0(2)°, respectively. The Sn—Cl bond
distances follow the series bridging Sn—Cl (2.813(2) Å) >>
axial Sn—Cl (2.365(3) Å) > equatorial Sn—Cl (2.319(3) Å,
2.311(3) Å). The Sn—Cl bond lengths in free MeSnCl3
(2.283(2), 2.318(1) Å) are similar to the Sn—-Cl(equatorial)
distances in 5. The intermolecular Sn···ClSn bond distance
in MeSnCl3 (Chart 1, D (13)) is 3.714(2) Å and is signifi-
cantly longer than the bridging Sn···Cl-Pt distance of
2.813(2) Å in complex 5. There are no short intermolecular
SnCl···Sn contacts involving the chloride ligands in the
PtSnMeCl2 and MeSnCl3 groups in complex 5. It is clear
therefore that the Pt-Cl group is a stronger donor than the
SnMeCl2 group.
bridging chloride. For example, in
6
the angles
Cl(45)Sn(41)C(42), Cl(45)Sn(41)C(43), and Cl(45)Sn(41)Cl(44)
(99.4(2), 97.7(2), and 96.6(1)°, respectively) are all greater
than 90°. The C-Sn-C angles for Me2SnCl2 in 6 (133.9(3)°)
and 8 (126(1)°) are larger than the ideal angle of 120°, and
the Cl···Sn-Cl bond angle (6, 177° (6), 8, 175.90(9)° (8)) is
close to linear in each complex. The order of the Sn—Cl
bond lengths again follows the series: bridging chloride
(3.04(1) Å (6), 2.870(3) Å (8)) >> axial chloride (2.457(3) Å
(6), 2.428(2) Å (8)) > equatorial chloride (2.342(2) (6),
2.313(7) Å (8)). For comparison, the Sn—Cl distance in
Me2SnCl2 is 2.40(4) Å and the intermolecular Sn···Cl dis-
tance is 3.54(5) Å (11). There are no short intermolecular
SnCl···Sn contacts in complexes 6 and 8, whereas such inter-
actions in Me2SnCl2 give rise to the infinite chain structure
C (Chart 1).
The structure of complex 3b is of particular interest,
and is shown in Fig. 4. Selected bond parameters are in
Table 2. There are two independent molecules of
[PtBrMe2(SnMe2Br)(bu2bpy)] and of Me2SnBr2 in the unit
cell. The independent platinum complexes differ primarily
The Cl···SnMe2Cl2 units in complexes 6 and 8 have simi-
lar distorted trigonal bipyramidal stereochemistries at tin,
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Janzen et al.
1455
Fig. 4. Views of the structure of complex 3b: (a) the two inde-
by rotation about the Pt—Sn bond, and the independent
Me2SnBr2 molecules differ mostly by rotation about the
bridging PtBr···Sn bond, as shown in Fig. 4a. There is a
clear PtBr···Sn secondary bond to each molecule of
Me2SnBr2 with distances Br(1)···Sn(60) and Br(2)···Sn(70)
of 3.14 and 3.29 Å. There are also longer contacts between
the bromide atoms of the PtSnMe2Br groups and the
Me2SnBr2 groups. These distances Br(26)···Sn(70) and
Br(56)···Sn(60) are 3.99 and 4.05 Å, which is marginally
longer than the sum of the van der Waals radii of Br and Sn
of 3.95 Å (16). The orientation of the SnBr···Sn groups is
such that the bromide is directed towards the tin atom and
essentially bisects the C-Sn-C angle of the Me2SnBr2 accep-
tor molecule. This orientation, observed in both independent
units, suggests that there is an attraction involved but it must
be a very weak one. To place these distances in perspective,
the covalent bond distances are Sn(23)—Br(26) = 2.533(1)
and Sn(53)—Br(56) = 2.557(1) Å for the PtSnMe2Br groups
and for the Me2SnBr2 molecules, pseudo-axial Sn(60)—
Br(63) = 2.558(1), Sn(70)—Br(74) = 2.587(1) Å and
pseudo-equatorial Sn(60)—Br(64) = 2.492(1), Sn(70)—
Br(73) = 2.499(1) Å. The differences between primary and
secondary Sn—Br distances is then approximately 0.64 Å
for the pseudo-axial bonds and 1.52 Å for the pseudo-
equatorial bonds, again emphasizing that the PtBr···Sn sec-
ondary bonds are strong relative to the PtSnBr···Sn interac-
tions. In the solid state structure of Et2SnBr2, the difference
between primary and secondary Sn—Br distances is 1.27 Å,
about midway between the values for the stronger and
weaker secondary interactions in 3b.
pendent units [PtBrMe2(SnMe2Br)(bu2bpy)]·Me2SnBr2; (b) part of
the folded polymeric structure formed by secondary Br···Sn
bonding. Only the inner atoms of the bu2bpy ligands are shown
for clarity.
Another criterion for the strength of the secondary bond-
ing is based on the stereochemistry at tin in the Me2SnBr2
acceptor molecules. In trigonal bipyramidal [SnMe2Br3]– the
C-Sn-C angle is 133.2(8)°, whereas in octahedral
[SnMe2Br4]2– the angle is 180° (14). In 3b, the C-Sn-C an-
gles are 131.9(3)° and 137.4(4)° for the two independent
Me2SnBr2 acceptor molecules, very similar to the angle in
the trigonal bipyramidal model compound. The analogous
angle in the Me2SnCl2 complex (6) is 133.9(3)°, again very
similar to the average C-Sn-C angle in 3b. These data also
indicate that the secondary SnBr···Sn bonding must be very
weak, since the stereochemistry at the acceptor molecule is
not significantly affected by it. If both types of secondary
bonds are included, the solid state structure can be consid-
ered as a folded polymer, as illustrated in Fig. 4b.
Overall, it is clear that the secondary bonds formed by
dimethyltin dihalide or methyltin trihalide acceptors can lead
to supramolecular association and even to polymer forma-
tion in the solid state. At present, though, it is not easy to
predict or control the degree of association. The secondary
X···Sn bonds are weak coordinate bonds, and they appear to
have similar energies to hydrogen bonds, aryl–aryl second-
ary bonds, or aurophilic attractions that have been used more
extensively in supramolecular chemistry for assembling com-
plex organometallic structures (11, 17). There is therefore a
clear potential for further expansion of this field of research.
ported in ppm with respect to TMS (1H) reference. Unless
otherwise specified, all quoted couplings to tin are for the
119Sn
isotope
only.
[PtMe2(bu2bpy)]
(18)
and
[(PtClMe2bu2bpy)2( -SnCl2)] (2) were prepared according to
the literature procedures.
[PtClMe2(SnMe2Cl)(bu2bpy)]·Me2SnCl2 (3a)
Experimental
An NMR tube was charged with 1 (40 mg, 0.081 mmol),
Me2SnCl2 (178 mg, 0.810 mmol), and CH2Cl2 (0.5 mL).
After 5 min, pentane was slowly layered on top of the solution
NMR spectra were recorded by using Varian Mercury 400
or Inova 600 MHz spectrometers. Chemical shifts are re-
© 2002 NRC Canada

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Can. J. Chem. Vol. 80, 2002
Table 2. Selected bond distances (Å) and angles (°) for complex 3b.
Pt(1)—Br(1)
2.675(1)
2.5332(7)
2.533(1)
2.148(8)
2.146(8)
2.558(1)
2.492(1)
2.117(8)
2.119(7)
3.29
Pt(2)—Br(2)
2.706(1)
2.5465(7)
2.557(1)
2.135(8)
2.130(7)
2.499(1)
2.587(1)
2.115(8)
2.105(9)
3.14
Pt(1)—Sn(23)
Sn(23)—Br(26)
Sn(23)—C(24)
Sn(23)—C(25)
Sn(60)—Br(63)
Sn(60)—Br(64)
Sn(60)—C(61)
Sn(60)—C(62)
Sn(60)···Br(1)
Br(56)···Sn(60)
Pt(2)—Sn(53)
Sn(53)—Br(56)
Sn(53)—C(54)
Sn(53)—C(55)
Sn(70)—Br(73)
Sn(70)—Br(74)
Sn(70)—C(71)
Sn(70)—C(72)
Sn(70)···Br(2)
Br(26)···Sn(70)
4.05
3.99
C(24)-Sn(23)-C(25)
C(24)-Sn(23)-Br(26)
C(25)-Sn(23)-Br(26)
C(61)-Sn(60)-C(62)
C(61)-Sn(60)-Br(63)
C(61)-Sn(60)-Br(64)
C(62)-Sn(60)-Br(63)
C(62)-Sn(60)-Br(64)
Br(63)-Sn(60)-Br(64)
Br(1)···Sn(60)-Br(63)
Br(1)···Sn(60)-Br(64)
Br(56)···Sn(60)-Br(63)
Br(56)···Sn(60)-Br(64)
Sn(60)···Br(1)-Pt(1)
Sn(60)···Br(56)-Sn(53)
111.8(4)
103.3(3)
101.5(2)
131.9(3)
100.6(3)
113.7(3)
99.8(2)
106.6(3)
96.60(4)
178
C(54)-Sn(53)-C(55)
C(54)-Sn(53)-Br(56)
C(55)-Sn(53)-Br(56)
C(71)-Sn(70)-C(72)
C(71)-Sn(70)-Br(73)
C(71)-Sn(70)-Br(74)
C(72)-Sn(70)-Br(73)
C(72)-Sn(70)-Br(74)
Br(73)-Sn(70)-Br(74)
Br(2)···Sn(70)-Br(73)
Br(2)···Sn(70)-Br(74)
Br(26)···Sn(70)-Br(73)
Br(26)···Sn(70)-Br(74)
Sn(70)···Br(2)-Pt(2)
Sn(70)···Br(26)-Sn(23)
113.9(4)
100.6(3)
102.9(2)
137.4(4)
107.6(2)
98.4(3)
110.3(3)
95.4(3)
97.27(4)
88
85
84
177
127
173
174
89
126
150
166
and the sample stored at –5°C. After several days colorless
crystals suitable for X-ray crystallographic studies were
[PtClMe2(SnMeCl2)(bu2bpy)]·Me2SnCl2 (6)
This was prepared similarly from 1 (40 mg, 0.081 mmol),
MeSnCl3 (20 mg, 0.081 mmol), and CH2Cl2 (0.5 mL) fol-
lowed by addition of Me2SnCl2 (89 mg, 0.405 mmol). Yield
formed. Yield 72%. 1H NMR (CDCl3) ꢀ: 8.76 (d, 2H, 3JH6H5
=
6 Hz, 3JPtH6 = 16 Hz, H-6, 8.11 (d, 2H, 4JH3H5 = 1.5 Hz, H-3),
3
4
77%. 1H NMR (CDCl3) ꢀ: 8.74 (d, 2H, 3JH6H5 = 6 Hz, 3JPtH6
=
7.60 (dd, 2H, JH5H6 = 6 Hz, JH5H3 = 1.5 Hz, H-5), 1.43 (s,
18H, t-bu), 1.32 (s, 6H, JPtMe = 55 Hz, Pt-Me), 1.18 (s, 6H,
2
4
15 Hz, H-6), 8.43 (d, 2H, JH3H5 = 2 Hz, H-3), 7.72 (dd, 2H,
2
2JSnH = 68.5 Hz, free Me2SnCl2), 0.38 (br s, 6H, JSnH
=
4
3JH5H6 = 6 Hz, JH5H3 = 2 Hz, H-5), 1.48 (s, 18H, t-bu), 1.45
2
2
50 Hz, Sn-Me). Anal. calcd. for C24H42Cl4N2PtSn2 (%):
C 30.90, H 4.54, N 3.00; found: C 30.77, H 4.46, N 2.94.
(s, 6H, JPtMe = 56 Hz, Pt-Me), 1.18 (s, 6H, JSnH = 68 Hz,
2
free Me2SnCl2), 1.03 (s, 3H, JSnH = 52 Hz, Sn-Me). Anal.
calcd. for C23H39Cl5N2Pt (%): C 28.98, H 4.12, N 2.94;
found: C 28.90, H 4.06, N 2.88.
[PtBrMe2(SnMe2Br)(bu2bpy)]·Me2SnBr2 (3b)
This was prepared similarly but using Me2SnBr2 in place
[(PtClMe2bu2bpy)2( -SnCl2)]·Me2SnCl2 (8)
1
of Me2SnCl2. Yield 74%. H NMR (CDCl3) ꢀ: 8.78 (d, 2H,
This was prepared similarly from complex 9 (45 mg,
0.035 mmol), Me2SnCl21 (38 mg, 0.175 mmol), and CH2Cl2
(0.5 mL). Yield 83%. H NMR (CDCl3) ꢀ: 8.69 (d, 2H,
3
4
3JH6H5 = 4.5 Hz, JPtH6 = 16 Hz, H-6), 8.11 (d, 2H, JH3H5
=
1 Hz, H-3), 7.60 (dd, 2H, 3JH5H6 = 4.5 Hz, 4JH5H3 = 1 Hz, H-5),
1.43 (s, 18H, t-bu), 1.42 (s, 6H, 2JPtMe = 56 Hz, Pt-Me), 1.34
3
6
4
3JH6H5 = 6 Hz, JPtH = 16 Hz, H-6), 8.07 (d, 2H, JH3H5
=
2
(s, 6H, JSnH = 65 Hz, free Me2SnBr2), 0.46 (br s, 6H,
3
4
1 Hz, H-3), 7.55 (dd, 2H, JH5H6 = 6 Hz, JH5H3 = 1 Hz,
2JSnH = 49 Hz, Sn-Me). Anal. calcd. for C24H42Br4N2PtSn2
2
H-5), 1.40 (s, 36H, t-bu), 1.36 (br s, 12H, JPtMe = 59 Hz,
Pt-Me), 1.18 (s, 6H, JSnH = 68 Hz, free Me2SnCl2). Anal.
(%): C 25.95, H 3.81, N 2.62: found: C 26.05, H 3.89, N 2.63.
2
calcd. for C43H66Cl6N4Pt2Sn2·pentane (%): C 36.67, H 5.11,
N 3.64; found: C 36.75, H 5.18, N 3.70.
[PtClMe2(SnMeCl2)(bu2bpy)]·MeSnCl3 (5)
This was prepared similarly from 1 (40 mg, 0.081 mmol),
MeSnCl3 (195 mg, 0.810 mmol), and CH2Cl2 (0.5 mL).
(PtClMe2bu2bpy)( -SnCl2)(PtMe2bu2bpy)(CF3SO3) (9)
To a solution of 9 (100 mg, 0.078 mmol) in CH2Cl2
(10 mL) was added AgO3SCF3 (20 mg, 0.078 mmol), and
the mixture was stirred for 30 min in the dark. The solution
was filtered through dry celite to remove AgCl. Pentane
(40 mL) was added to the filtrate to precipitate the product,
which was isolated by filtration, washed with pentane, and
1
3
Yield 68%. H NMR (CDCl3) ꢀ: 8.74 (d, 2H, JH6H5 = 6 Hz,
3JPtH6 = 15 Hz, H-6), 8.43 (d, 2H, JH3H5 = 2 Hz, H-3), 7.72
4
3
4
(dd, 2H, JH5H6 = 6 Hz, JH5H3 = 2 Hz, H-5), 1.67 (s, 6H,
2JSnH = 99 Hz, free MeSnCl3), 1.48 (s, 18H, t-bu), 1.45 (s,
2
2
6H, JPtMe = 56 Hz, Pt-Me), 1.03 (s, 3H, JSnH = 52 Hz,
Sn-Me). Anal. calcd. for C22H36Cl6N2PtSn2 (%): C 27.14,
H 3.73, N 2.88; found: C 27.07, H 3.65, N 2.77.
1
dried in vacuo. Yield 88%. H NMR (CDCl3) ꢀ: 8.55 (br d,
© 2002 NRC Canada

Janzen et al.
1457
Table 3. Crystal data and experimental details.
Complex
5
3b
6
8·pentane
Empirical formula
Formula weight
T (°C)
C22H36Cl6N2PtSn2
973.7
25(2)
C24H42Br4N2PtSn2
1110.71
–123(2)
C23H39Cl5N2PtSn2
953.28
–123(2)
C47H78Cl6N4Pt2Sn2
1539.39
21(2)
ꢁ (Å)
Space group
a (Å)
b (/Å)
c (Å)
0.71073
P21/c
0.71073
P21/c
0.71073
P21/c
0.71073
P21/n
12.1321(2)
25.9092(5)
12.0843(2)
118.490(1)
3338.5(1)
4
23.8100(7)
13.4608(3)
22.0228(6)
106.169(1)
6779.1(3)
8
12.5953(5)
24.6511(6)
11.9861(5)
118.111(2)
3282.5(2)
4
18.7589(4)
13.5089(3)
22.7772(5)
92.835(1)
5765.0(2)
4
ꢂ (°)
V (Å3)
Z
Dcalcd. (g cm–1)
1.937
2.177
1.929
1.774
Absorption coefficient (mm)
F(000)
R [I > 2ꢃ(I)]a
6.159
1848
10.309
4144
6.183
1816
6.006
2984
R1
wR2
0.0510
0.1444
0.0471
0.0898
0.0397
0.0634
0.0576
0.1422
2
2
aR1 = ꢄ(**Fo*–*Fc**)/ꢄ*Fo*; wR2 = [ꢄw(Fo – Fc2)2/ꢄwFo ]1/2
.
3
A.L. Spek, and G. van Koten. J. Chem. Soc. Chem. Commun.
1367 (1990); (c) I.C.M. Wehman-Ooyevaar, D.M. Grove,
H. Kooijman, P. van der Sluis, A.L. Spek, and G. van Koten.
J. Am. Chem. Soc. 114, 9916 (1992).
2H, JH6H5 = 6 Hz, H-6), 8.07 (br s, 2H, H-3), 7.59 (d, 2H,
3JH5H6 = 6 Hz, H-5), 1.38 (s, 36H, t-bu), 1.07 (br s, 12H, Pt-
Me). Anal. calcd. for C41H60Cl3F3N4O3Pt2SSn (%): C 36.18,
H 4.44, N 4.12; found: C 36.10, H 4.38, N 4.02.
4. V.G. Albano, C. Castellari, V. De Felice, A. Panunzi, and F.
Ruffo. J. Organomet. Chem. 425, 177 (1992).
5. (a) G. Butler, C. Eaborn, and A. Pidcock. J. Organomet. Chem.
181, 47 (1979); (b) G. Butler, C. Eaborn, and A. Pidcock. J.
Organomet. Chem. 185, 367 (1980).
6. J. Kuyper. Inorg. Chem. 17, 77 (1978).
7. M.S. Holt, W.L. Wilson, and J.H. Nelson. Chem. Rev. 89, 11
(1989).
8. (a) C.J. Levy, J.J. Vittal, and R.J. Puddephatt. Organo-
metallics, 15, 2108 (1996); (b) C.J. Levy, J.J. Vittal, and R.J.
Puddephatt. Organometallics, 15, 35 (1996).
9. H. Preut and F. Huber. Acta Crystallogr. B35, 744 (1979).
10. (a) A.G. Davies. In Organotin chemistry. VCH, New York.
1997; (b) P.J. Smith (Editor). Chemistry of tin. Blackie Aca-
demic and Professional, New York. 1998.
11. I. Haiduc and F.T. Edelmann. Supramolecular organometallic
chemistry. Wiley-VCH, New York. 1999.
12. (a) A.G. Davies, H.J. Milledge, D.C. Puxley, and P.J. Smith. J.
Chem. Soc. A, 2862 (1970); (b) N.W. Alcock and J.F. Sawyer.
J. Chem. Soc. Dalton Trans. 1090 (1977).
X-ray structure determinations
Crystals were mounted on glass fibers. Data were col-
lected by using a Nonius Kappa-CCD diffractometer with
COLLECT (Nonius, 1998) software. Crystal cell refinement
and data reduction were carried out using the Nonius
DENZO package. The data were scaled using SCALEPACK
(Nonius, 1998), and no other absorption corrections were
applied. The SHEXTL 5.1 (G.M. Sheldrick, Madison, Wisc.)
program was used to solve the structures by direct methods,
followed by refinement by successive difference Fouriers.
For complex 5 the tert-butyl groups were modeled as two
half-occupancy isotropic groups. For 8 there was disorder at
the SnMe2Cl2 acceptor, and atoms Cl(5) and C(62) were dis-
ordered across their two positions. This disorder was mod-
eled as 50% of each atom type with the Sn—Cl (2.39 Å) and
Sn—C (2.13 Å) distances being fixed. Crystal and refine-
ment data are listed in Table 3.
13. H.R. Hoveyda, C. Orvig, and S.J. Rettig. Acta Crystallogr. C,
50, 1904 (1994).
Acknowledgments
14. D. Tudela, M. Diaz, D.A. Alvaro, J. Ignacio, L. Seijo, and
V.K. Belsky. Organometallics, 20, 654 (2001).
15. (a) U. Fekl, W. Kaminsky, and K.I. Goldberg. J. Am. Chem.
Soc. 123, 6423 (2001); (b) S. Reinartz, P.S. White, M. Brookhart,
and J.L. Templeton. J. Am. Chem. Soc. 123, 6425 (2001).
16. A. Bondi. J. Phys. Chem. 68, 441 (1964).
We thank the Natural Sciences and Engineering Research
Council of Canada (NSERC) for financial support. RJP thanks
the government of Canada for a Canada Research Chair.
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© 2002 NRC Canada