Organoplatinum(iv) complexes with functional alkyl groups and their use in supramolecular chemistry1

Article abstract of DOI:10.1139/V09-031

The oxidative addition of alkyl bromides RCH₂Br (R = C ₅H₄N, C₆H₄CN, CH₂C ₆H₄CO₂H, or CH₂C₆H ₄CH₂CO₂H

Full text of DOI:10.1139/V09-031

904
Organoplatinum(IV) complexes with functional
alkyl groups and their use in supramolecular
chemistry1
Richard H.W. Au, Lisa J. Findlay-Shirras, Neil M. Woody, Michael C. Jennings, and
Richard J. Puddephatt
Abstract: The oxidative addition of alkyl bromides RCH2Br (R = C5H4N, C6H4CN, CH2C6H4CO2H, or CH2C6H4CH2CO2H)
to dimethylplatinum(II) complexes [PtMe2(LL)] (LL = diimine ligand) gives the corresponding organoplatinum(IV)
complexes [PtBrMe2(CH2R)(LL)] containing functionality in the alkyl group RCH2. The pyridyl derivatives can be
protonated, while abstraction of the bromide ligand from [PtBrMe2(CH2R)(LL)] can form cationic complexes, which
can react with water or form oligomers by self-assembly.
Key words: platinum, organometallic, hydrogen bond, supramolecular.
´
´
Resume : L’addition oxydante de bromures d’alkyle, RCH2Br [R = C5H4N, C6H4CN, CH2C6H4COOH ou CH2C6H4CH2COOH]
´
`
sur des complexes de dimethylplatine(II) [PtMe2(LL)] [LL = ligand diimine], conduit a la formation de complexes organo-
´
´
´
platine(IV) [PtBrMe2(CH2R)(LL)] comportant une fonctionnalite dans le groupe alkyle RCH2. Les derives pyridyles peu-
ˆ
´
`
`
`
vent etre protones alors que l’enlevement du ligand bromure a partir de [PtBrMe2(CH2R)(LL)] peut conduire a la formation
´
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de complexes cationiques qui peuvent reagir avec de l’eau ou former des oligomeres par autoassemblage.
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Mots-cles : platine, organometallique, liaison hydrogene, supramoleculaire.
´
[Traduit par la Redaction]
bipyridine (bu2bipy) or di-2-pyridyl ketone (DPK), respec-
tively, gave the products of trans oxidative addition
[PtBrMe2(CH2C6H4-3-CN)(LL)], 3 or 4 (Scheme 1).
Introduction
The oxidative addition of small molecules to platinum(II)
complexes to form organoplatinum(IV) complexes can be a
key step in catalysis, and so this type of reaction has been
studied in great detail.2–6 The oxidative addition can also be
a key step in the synthesis of binuclear or even polymeric
organoplatinum(IV) complexes, which are of interest as mo-
lecular materials.4–8 The building up of complex structures
from simple building blocks is a feature of supramolecular
chemistry,9 and organoplatinum(IV) complexes have proved
to be very versatile in the development of supramolecular
organometallic chemistry of the transition metals.10–14 The
stability of organoplatinum(IV) complexes towards reactions
of protic reagents, oxidants, and other functional groups is
an important property in allowing this chemistry to be de-
veloped.15 This paper describes chemistry of new organopla-
tinum(IV) complexes in which one of the alkyl groups
carries a cyanide, a pyridine, or a carboxylic acid group.
The complexes were readily characterized by their 1H
NMR spectra. For example, complex 3 gave a single meth-
ylplatinum resonance at d = 1.51 with coupling constant
2J(PtH) = 69 Hz, and a single Pt-CH2 resonance at d = 2.79
2
with coupling constant J(PtH) = 96 Hz, indicating forma-
tion of a single symmetrical isomer. Complex 3 was also
characterized by X-ray structure determination (Fig. 1). The
platinum(IV) centre has octahedral stereochemistry and the
cyanophenyl group lies over one of the pyridyl groups of
the bu2bipy ligand.
The reactions of complex 1 with the three isomers of bro-
momethylpyridine are shown in Scheme 2. The organic re-
agents are available only as the hydrobromide salts, because
the neutral compound self-react, but the simple reaction of
the bromomethylpyridinium bromides were complex. They
evidently act as a source of HBr, which reacts with 1 to
give methane and [PtBrMe(bu2bipy)], which can itself react
with bromomethylpyridine. To obtain the products of
Scheme 2, the pyridinium salts were neutralized with trie-
thylamine to generate the neutral bromomethylpyridine in
situ, and this solution was then used to react with complex
1. Each of the complexes [PtBrMe2(CH2py)(bu2bipy)], 5–7
Results
Formation of organoplatinum(IV) complexes through
oxidative addition reactions
The oxidative addition of 3-cyanobenzyl bromide to com-
plexes [PtMe2(LL)], 1 or 2, where LL = 4,4’-di-t-butyl-2,2’-
Received 28 November 2008. Accepted 21 January 2009. Published on the NRC Research Press Web site at canjchem.nrc.ca on 20 May
2009.
R.H.W. Au, L.J. Findlay-Shirras, N.M. Woody, M.C. Jennings, and R.J. Puddephatt.1 Department of Chemistry, University of
Western Ontario, London, ON N6A 5B7, Canada.
1Corresponding author (e-mail: pudd@uwo.ca).
Can. J. Chem. 87: 904–916 (2009)
doi:10.1139/V09-031
Published by NRC Research Press

Au et al.
905
Scheme 1.
Scheme 2.
Fig. 1. Structure of [PtBrMe2(CH2C6H4-3-CN)(bu2bipy)], 3. Se-
lected bond parameters: Pt–C(1) 2.06(1), Pt–C(2) 2.04(1), Pt–C(31)
2.10(1), Pt–N(11) 2.17(1), Pt–N(22) 2.13(1), Pt–Br 2.582(1),
˚
C(38)–N(39) 1.15(2) A.
(py = 2-, 3-, or 4-C5H4N, respectively), gave a single meth-
ylplatinum resonance and a single PtCH2 resonance in the
1H NMR spectra, thus confirming that selective trans oxida-
tive addition of the C–Br bond had occurred. The structure
of complex 5 was confirmed by X-ray structure determina-
tion and is shown in Fig. 2. There are two independent mol-
ecules in the asymmetric unit, but they have similar
structures and so only one is shown in Fig. 2. As in complex
3 (Fig. 1), the platinum(IV) centre has octahedral stereo-
chemistry and the 2-pyridyl unit of the PtCH2py group is p-
stacked with one of the pyridyl groups of the bu2bipy ligand.
The oxidative addition reactions of some bromomethyl
derivatives of carboxylic acids are shown in Scheme 3. In
all cases, trans oxidative addition was observed to give the
products 8–11. However, the DPK complexes also gave
some cis isomer. Complexes 8 and 10 have been reported
previously but the structures were not determined.10
trated in Figs. 4 and 5. The molecular structure is similar to
that of complex 8 (Figs. 3 and 4), but there is disorder of the
CH2C6H4CH2CO2H groups with roughly 50:50 occupation
of the A [containing O(40) and O(41)] and B [containing
O(60) and O(61)] forms. The supramolecular structure of 10
is more complex than for 8 (compare Figs. 3 and 5). The
head-to-head dimerization of the type seen for 8 is not ob-
served for complex 10. Instead, the molecules of the form
A and B alternate in forming hydrogen bonds O(61)=C(R)–
O(60)HÁÁÁO(41)=C(R)–O(40)HÁÁÁBr. Molecule A acts as a
hydrogen bond donor to the Br–Pt group of molecule B,
and a hydrogen bond acceptor through its carbonyl oxygen
atom. Molecule B acts as a hydrogen bond donor to the car-
bonyl group of molecule A and an acceptor through its Br–
Pt group. The overall result is to form a hydrogen-bonded
supramolecular polymer.
The structure of complex 8 is shown in Fig. 3. The com-
plex forms a hydrogen bonded dimer in the solid state with
˚
a distance of O(39)ÁÁÁO(40A) = O(40)ÁÁÁO(39A) = 2.61(1) A.
The structure of complex 10 is more complex and is illus-
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Can. J. Chem. Vol. 87, 2009
Fig. 2. The structure of [PtBrMe2(CH2-2-py)(bu2bipy)], 5. Selected
bond distances: Pt(1)–C(1) 2.04(1), Pt(1)–C(3) 2.08(1), Pt(1)–C(31)
2.10(1), Pt(1)–N(11) 2.136(9), Pt(1)–N(22) 2.166(9), Pt(1)–Br(1)
Scheme 3.
˚
2.5618(15) A.
Further derivatization of the platinum(IV) complexes
The pyridyl complexes 5–7 could be protonated by addi-
tion of acid, as shown for the protonation of 4-pyridylme-
thylplatinum(IV) derivative (7) to give 12 in Scheme 4. The
1
main effect on the H NMR spectra was a shift of the PtCH2
resonance on protonation. This shift defined as D(d) = d(pro-
tonated complex) – d(parent complex) = 1.78, 0.52, and 0.32
for the 2-, 3-, and 4-pyridylmethyl derivative, respectively.
Two complications were observed in these reactions. Firstly,
the reversible isomerization of 12 to the overall product of
cis oxidative addition (13, in Scheme 4) was catalyzed by
acid. It was not possible to isolate the cis isomers such as
13, but these compounds could be identified by their NMR
spectra. For example, the low symmetry of 13 leads to
nonequivalent MePt resonances [d(PtMe, axial) = 0.76,
2J(PtH) = 72 Hz; d(PtMe, equatorial) = 1.05, 2J(PtH) =
2
68 Hz] and PtCHaHbpy protons [d(PtHa) = 3.54, J(HH) =
2
2
7 Hz, J(PtH) = 105 Hz; d(PtHb) = 4.41, J(HH) = 7 Hz,
2J(PtH) = 110 Hz] in the H NMR spectrum. The isomeriza-
1
tion is expected to occur after bromide dissociation to give a
five-coordinate intermediate [PtMe2(CH2-4-py)(bu2bipy)]+,
and this reversible step is catalyzed by H+.16 At equilibrium,
the ratio of 12:13 was ca. 3:1 when X = triflate. A similar
isomerization occurred on protonation of the 3-pyridylme-
thylplatinum(IV) complex (6), but no cis isomer was de-
tected on protonation of the 2-pyridylmethylplatinum(IV)
complex (5). The second complication is that, if the group
X in the acid HX can act as a ligand for platinum(IV), then
partial exchange of the bromide ligand for X– can occur. For
example, crystallization of complex 7 in the presence of HCl
gave complex 12 (X = Cl), but crystallographic characteriza-
tion of the product showed partial displacement of the PtBr
by the PtCl group to give 14 (Scheme 4, X = Cl). The struc-
ture of 12 (X = Cl) is shown in Fig. 6, showing only the Pt-
Br component. The ratio of disorder components 12:14 (X =
Cl) was refined as 0.36:0.64. The possibility of supramolec-
ular association between the pyridyl base 7 and the acidic
complexes 8 or 10 was investigated, but no such acid–base
adducts could be crystallized.
The reactions of the pyridyl complexes 5–7 with silver
salts of weakly coordinating anions were expected to occur
by bromide abstraction followed by intramolecular or inter-
molecular coordination of the pyridine nitrogen atom to plat-
inum(IV), as illustrated in Scheme 5.17 The reaction of
complex 5 with silver triflate occurred according to
Scheme 5, and the product 15(OTf) was isolated in analyti-
cally pure form, though single crystals could not be ob-
1
tained. The H NMR spectrum of 15 was broad at room
temperature but, at –20 8C, it clearly showed two methylpla-
tinum resonances and an [AB] multiplet for the PtCHaHb
1
protons. However, the H NMR spectra of compounds ob-
tained by treating the cyanobenzyl complex 3, or the 3- or
4-pyridylmethyl complexes (6 or 7) with silver triflate were
very complex, indicating that the self-assembly was nonse-
Published by NRC Research Press

Au et al.
907
Fig. 3. The structure of complex 8, showing the dimer formed by
H-bonding. Selected parameters: Pt–C(31) 2.04(2), Pt–C(1) 2.08(1),
Pt–C(2) 2.09(1), Pt–N(22) 2.16(1), Pt–N(11) 2.167(9), Pt–Br
Fig. 4. The 50:50 disordered structure of complex 10. Selected
parameters: Pt–C(1) 2.09(2), Pt–C(2) 2.07(2), Pt–C(31) 2.10(3), Pt–
C(51) 2.11(3), Pt–N(11) 2.16(1), Pt–N(22) 2.18(1), Pt–Br 2.601(2) A.
˚
˚
2.563(2) A. Hydrogen bond distance: O(39)ÁÁÁO(40A) =
˚
O(40)ÁÁÁO(39A) = 2.61(1) A.
Fig. 5. The supramolecular structure of complex 10, with alternat-
ing conformers A (red) and B (blue). Hydrogen-bonding para-
˚
meters: O(40)ÁÁÁBr 3.26(4), O(41)ÁÁÁO(60) 2.67(5) A. Other
sequences, such as (AABB)n can be ruled out because they lead to
unreasonably short contacts.
lective and gave a mixture of oligomers rather than a single
product such as 16. The unique behavior of the 2-pyridyl-
methyl complex (5) was also reflected in the ESI-MS of a
solution in dichloromethane. The 2-pyridylmethyl complex
(15), as the triflate salt, gave a molecular ion at m/z = 585,
whereas the corresponding products with 3- or 4-pyridyl-
methyl groups gave the same envelope of peaks at m/z =
585 but also significant peaks at m/z = 1319 due to the
dimer ion [{PtMe2(CH2py)(bu2bipy)}2(OTf)]+ and, for the
4-pyridylmethyl complex only, trimer peaks.
Reaction of the toluic acid derivative (8) with silver tetra-
fluoroborate in moist solvent acetone occurred according to
Scheme 6, to give the cationic aqua complex 17, whose
structure is shown in Fig. 7. The stereochemistry at the octa-
hedral platinum(IV) centre is not changed in this reaction
and so the effect is to substitute the bromide ligand by the
aqua ligand. The carboxylic acid group hydrogen bonds to
an acetone molecule, while one hydrogen atom of the aqua
group hydrogen bonds to a second acetone molecule and the
other hydrogen bonds to the tetrafluoroborate anion. It was
anticipated that addition of base to complex 17 would give
the carboxylate anion and that this would in turn displace
the aqua ligand from a neighbouring molecule to give a
dimer or, by repletion of these steps, an oligomer or poly-
mer. However, the reaction gave only a mixture of com-
plexes that could not be characterized.
In some reactions of the platinum(IV) complexes with
DPK ligands with silver salts, the carbonyl group of the
DPK ligand was shown to be involved. The reaction of com-
plex 4 with silver triflate gave the cationic complex 18, as
the triflate salt, according to Scheme 7. The two key fea-
tures of complex 18 are the change in stereochemistry at
platinum(IV) and the hydration of the DPK ligand to give
the tridentate DPK-OH2 ligand. None of the more symmetri-
cal isomer, with the cyanobenzyl group trans to oxygen, was
1
detected. In the H NMR spectrum, complex 18 gave two
2
methylplatinum resonances [d = 1.18, J(PtH) = 72 Hz and
2
d = 1.48, J(PtH) = 81 Hz], and the PtCH2 group gave an
[AB] multiplet [d = 3.03, 2J(PtH) = 73 Hz; d = 3.55,
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908
Can. J. Chem. Vol. 87, 2009
Scheme 4.
Scheme 5.
Scheme 6.
Fig. 6. The structure of disordered complex 12/14 (X = Cl), show-
ing only component 12. Selected bond parameters: Pt–C(1) 2.09(2),
Pt–C(2) 1.99(3), Pt–C(31) 2.06(2), Pt–N(11) 2.15(2), Pt–N(22)
˚
2.10(2), Pt–Br 2.55(2) A. Hydrogen bond distance: N(35)ÁÁÁCl(1)
˚
3.61(3) A.
the carbonyl peak, found at 1677 cm–1 in 4 was absent in
18. Hydrogen bonding between at least one of the OH
groups in 18 to the cyano group was indicated by a shift in
the value of n(CN) from 2226 cm–1 in 4 to 2250 cm–1 in 18.
The peak assigned to n(OH) was broad and centred at
3250 cm–1, indicating that both OH groups are involved in
hydrogen bonding. The data are most consistent with hydro-
gen bonding to the nitrogen atom only of the cyano group,
because hydrogen bonding to the p-bond should lead to a
decrease in n(CN) whereas end-on hydrogen bonding leads
to an increase,18,19 but it is not clear if both OH groups hy-
drogen bond to the nitrogen atom or if one of them hydro-
gen bonds to the triflate anion. The stereochemical change
at platinum(IV) in converting 4 to 18 (Scheme 7) is presum-
ably in part to allow maximum hydrogen bonding. Intermo-
lecular OHÁÁÁNC hydrogen bonding could form a dimer,
2
2J(PtH) = 103 Hz; J(HH) = 10 Hz], and there were two sets
of pyridyl resonances. The ESI-MS gave a parent ion for 18
at m/z = 543 as well as a peak corresponding to a cation
formed by loss of water at m/z = 525. In the IR spectrum,
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Au et al.
909
Fig. 7. Structure of the aqua complex 17[BF4]Á2acetoneÁhexane.
Selected bond parameters: Pt–C(1) 2.049(7), Pt–C(2) 2.048(8), Pt–
C(31) 2.085(8), Pt–N(11) 2.154(6), Pt–N(22) 2.171(6), Pt–O
Fig. 8. Structure of the dimer of 19ÁCF3CO2. Selected bond dis-
tances: Pt(1)–C(16) 2.05(1), Pt(1)–C(17) 2.06(1), Pt(1)–C(21)
2.08(1), Pt(1)–N(1) 2.16(1), Pt(1)–N(13) 2.17(1), Pt(1)–O(15)
˚
˚
2.224(5) A. Hydrogen bond distances: OÁÁÁF(44) 2.703(9), OÁÁÁO(54)
2.188(9) A. Hydrogen bond distances: O(14)ÁÁÁO(81) 2.62(1),
˚
2.43(1), O(40)ÁÁÁO(64) 2.729(9) A.
O(15)ÁÁÁO(82) 2.59(1), O(29)ÁÁÁO(60) 2.61(1), O(44)ÁÁÁO(92) 2.65(2),
˚
O(45)ÁÁÁO(91) 2.56(1), O(59)ÁÁÁO(30) 2.61(1) A.
oligomer, or polymer. In the ESI-MS, an intense peak was at
m/z = 543, corresponding to the cation 18, and a less intense
peak assigned to a dimer was observed at m/z = 1235 [(2 Â
18) + OTf]. No trimer or higher mass peaks were detected.
There are several precedents for the hydration of the DPK
ligand and for participation in hydrogen bonding of the
DPK-OH2 ligand.20
anions, such as Ag[BF4] or Ag[PF6], gave products that con-
tained the cationic complex 19 but with unidentified side
products. We suggest that the hydrogen bonding by the
anion (Fig. 8) is significant in stabilizing 19 as the trifluor-
oacetate salt.
The reaction of complex 11 with siver trifluoroacetate oc-
curred to give the cationic complex 19 according to
Scheme 7. The reaction to give 19 occurred with a change
in stereochemistry at platinum(IV) but this reaction was less
1
selective and some trans isomer was also present. The H
NMR spectrum of the cis isomer 19 contained two methyl-
platinum resonances and two resonances for the PtCHaHb
protons, indicating the absence of a mirror plane of symme-
try. The structure of complex 19 as the trifluoroacetate salt
is shown in Fig. 8. There are two independent but similar
molecules in the unit cell, and they are connected by hydro-
gen bonding between the carboxylic acid groups. In addi-
tion, the two OH groups of the ketone hydrate are hydrogen
bonded to the trifluoroacetate anions. The hydrogen bond
Discussion
The oxidative addition reactions to give alkyl platinu-
m(IV) complexes tolerate a range of functional groups.4–
8,10–16
In particular, it is possible to incorporate either basic
or acidic groups into the organoplatinum(IV) products.8,10
The reactions of [PtMe2(LL)] with RCH2Br usually occur
by kinetic control to give the product of trans oxidative
addition, [PtBrMe2(CH2R)(LL)], by way of an ionic inter-
mediate, [PtMe2(CH2R)(LL)]+Br–.4 However, if the ionic in-
termediate is long-lived, or if the bromide ligand can
dissociate easily, the cis isomer may also be formed.4,16 Sev-
eral cases of isomerization were observed in this work, and
some insight into the reasons for this were sought by com-
putations using density functional theory (DFT).
˚
distances OÁÁO are in the range of 2.59–2.65 A. In the ESI-
MS, the most intense envelope of peaks was at m/z = 576,
corresponding to the cation 19, with the second most intense
peak at m/z = 558, corresponding to loss of H2O. However,
intense dimer peaks were also observed at m/z = 1151 [(2 Â
19) – H+], 1133 [(2 Â 19) – H+ – H2O], and 1115 [(2 Â
19) – H+ – 2H2O]. The trifluoroacetate groups were not
present in any observed fragments. These data indicate that
the dimer units persist in solution, and that loss of water
from the DPK-OH2 groups occurs easily in the MS. Reac-
tions of complex 11 with silver salts of weakly coordinating
For
the
complexes
[PtBrMe2(CH2R)(bipy)]
or
[PtBrMe2(CH2R)(DPK)], the trans isomer is calculated to be
more stable than the cis isomer in all cases. The example
with R = 2-pyridyl is illustrated in Figs. 9a and 9b. The
trans isomer has a preferred conformation with the 2-pyridyl
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Can. J. Chem. Vol. 87, 2009
Scheme 7.
Fig. 9. Optimized structures and calculated relative energies
(kJ mol–1) of trans and cis isomers, respectively: (a),
(b) [PtBrMe2(CH2-2-py)(bipy)]; (c), (d) [PtMe2(CH2-2-py)(OH2)(-
bipy)]+; (e), (f) [PtMe2(CH2-2-py)(bipy)]+.
group p-stacked with the 2,2’-bipyridine ligand (Fig. 9a) but
there is little barrier to rotation about the Pt–CH2R bond for
the cis isomer. The cis isomer can be more stable if there is
a specific bonding effect in its favour. For example, the hy-
pothetical aqua complex, [PtMe2(CH2-2-py)(OH2)(bipy)]+, is
more stable as the cis isomer because an intramolecular hy-
drogen bond OHÁÁÁN can exist between the aqua ligand and
the 2-pyridyl group (Figs. 9c, 9d). Similarly, the intermedi-
ate five-coordinate complex [PtMe2(CH2-2-py)(bipy)]+ is
more stable as the cis isomer because the pyridylmethyl
group can chelate to platinum (Figs. 9e, 9f). Ring strain in
the PtCH2-2-py chelate unit allows easy dissociation of the
Pt–N bond. Thus, a conformation with d(Pt–N) increased
from the optimized value of 2.23 A (Fig. 9f) to 2.66 A,
with corresponding opening of the angle Pt–C–C(py) from
938 to 1048, was only 18 kJ mol–1 higher in energy. Easy
reversible access to the coordinatively unsaturated square
pyramidal intermediate accounts for the easy fluxionality in
complex 15.
˚
˚
A further complication in the chemistry of the DPK com-
plexes arose from the ease of hydration of the ketone group.
Some trimethylplatinum(IV) model complexes, used to
avoid complications from cis and trans isomers in the actual
complexes studied, are shown in Fig. 10. The ketone addi-
Published by NRC Research Press

Au et al.
911
Fig. 11. Optimized structures and calculated relative energies (kJ
Fig. 10. Optimized structures and calculated relative energies (kJ
mol–1) of (a) [Pt(OH)Me3(DPK)], (b) [PtMe3(DPK-OH)]; (c)
[PtMe3(OH2)(DPK)]+, (d) [PtMe3(DPK-OH2)]+; (e)
mol–1) of (a), (b) trans- and cis-[PtBrMe2(CH2-3-C6H4CN)(DPK)];
(c), (d) trans- and cis-[PtMe2(CH2-3-C6H4CN)(DPK-OH2)]+; (e), (f)
cis-[PtMe2(CH2-3-C6H4CN)(DPK-OH2)]+ in conformations without
and with OHÁÁÁNC hydrogen bonding, respectively.
[PtMe3(OH2)(DPK)][MeCO2], (f) [PtMe3(DPK-OH2)][MeCO2].
defined. The easy trans and cis isomerism and the easy hy-
dration of the DPK ligand makes crystal engineering in
these compounds challenging, and the relatively slow rate
of ligand substitution at platinum(IV) limits the use of dy-
namic coordination chemistry for self-assembly. However,
the use of hydrogen bonding for self-assembly has given in-
teresting supramolecular dimers and a polymer, which have
been structurally characterized.
tion step is calculated to be favorable for conversion of neu-
tral complex [Pt(OH)Me3(DPK)] to [PtMe3(DPK-OH)]
(Figs. 10a, 10b). However, for the protonated cationic com-
plexes [PtMe3(OH2)(DPK)]+ and [PtMe3(DPK-OH2)]+, the
ketone addition step is unfavorable (Figs. 10c, 10d). Addition
of an acetate anion, which can form a hydrogen bond with
the aqua or DPK-OH2 ligand, is enough to make the ketone
addition step favorable, as illustrated in Figs. 10e and 10f.
These calculations rationalize the observation that, in all
known complexes of the DPK-OH2 ligand, including com-
plex 19, the OH groups are involved in hydrogen bonding
and that hydration is easily reversible.20,21 The ligand DPK
can form a hydrate in hydrochloric acid solution, under con-
ditions where both pyridyl groups are protonated and there is
hydrogen bonding between the C–OH groups and chloride
anions, but the neutral ketone DPK is not hydrated.22
A feature of the complexes 18 and 19 with the DPK-OH2
ligand is that the cis isomer is preferred. Calculations indi-
cate that the trans isomer is expected to be more stable in
the absence of hydrogen bonding, for both the ligand DPK
and DPK-OH2, as seen in Figs. 11a, 11b and Figs. 11c,
11d, respectively. For the cis isomer of the 3-cyanobenzyl
derivative (18), intramolecular hydrogen bonding is possible
and this greatly stabilizes this isomer, as illustrated in
Figs. 11e and 11f. For complex 19, intramolecular hydrogen
bonding is not possible and the carboxylic acid group is in-
volved in intermolecular hydrogen bonding (Fig. 9). In this
case, the intermolecular hydrogen bonding is less favored
for the trans isomer because of steric effects in the confor-
mation with the aryl group lying over the DPK-OH2 ligand
and so the cis isomer is preferred.
Experimental
All reactions were performed under a nitrogen atmosphere
using standard Schlenk techniques. The complexes
[Pt2Me4(m-SMe2)2],
[PtMe2(bu2bipy)],
[PtMe2(DPK)],
[PtBrMe2(bu2bipy)(CH2-4-C6H4CO2H)], 8, and [PtBrMe2(-
bu2bipy)(CH2-4-C6H4CH2CO2H)], 10, were prepared using
1
the literature methods.10,23,21 1-D and 2-D H NMR spectra
were recorded using a Varian Mercury 400 NMR or a Var-
ian Inova 400 NMR spectrometer at room temperature un-
less specified otherwise. ESI-MS were recorded using a
Micromass LCT spectrometer. DFT calculations were car-
ried out using the Becke–Perdew exchange-correlation func-
tional in the Amsterdam Density Functional program,24
including first-order scalar relativistic corrections and stand-
ard parameters used in previous studies of organoplatinum
compounds.2,25
[PtBrMe2(3-CH2C6H4CN)(bu2bipy)], 3
To a solution of [PtMe2(bu2bipy)] (0.1096 g, 0.22 mmol)
in CH2Cl2 (5 mL) was added a solution of a-bromo-m-tolu-
nitrile (0.0463 g, 0.24 mmol) in CH2Cl2 (5 mL). The solu-
tion was stirred for 30 min, the volume of solvent was
reduced under vacuum, and the product was precipitated by
addition of pentane (10 mL) and recrystallized from CH2Cl2/
1
pentane. Yield: 0.085 g (0.12 mmol). H NMR (CD2Cl2) d:
2
1.43 [s, 18H, t-Bu], 1.51 [s, 6H, J(PtH) = 69 Hz, MePt],
Overall, this work has significantly expanded the range of
known organoplatinum complexes containing functional al-
kyl groups. Some of the strengths and limitations in the use
of these compounds in supramolecular chemistry are also
2
4
2.79 [s, 2H, J(PtH) = 96 Hz, CH2Pt], 6.19 [t, 1H, J(HH) =
2 Hz, C6H4-H2], 6.76 [d, 1H, J(HH) = 7 Hz, C6H4-H5], 6.79
3
[m, 1H, J(HH) = 7 Hz, J(HH) = 2 Hz, C6H4-H6], 6.95 [m,
3
4
Published by NRC Research Press

912
Can. J. Chem. Vol. 87, 2009
3
4
1H, J(HH) = 7 Hz, J(HH) = 2 Hz, C6H4-H4], 7.93 [dd, 2H,
3J(HH) = 6 Hz, 4J(HH) = 2 Hz, bipy-H5], 7.95 [d, 2H,
4J(HH) = 2 Hz, bipy-H3], 8.58 [d, 2H, 3J(HH) = 6 Hz,
bipy-H6]. ESI-MS m/z: 609 (100) [PtMe2(bu2bipy)(3-
CH2C6H4CN)]+. Anal. calcd. for C28H36BrN3Pt (%): C
48.77, H 5.26, N 6.09; found: C 48.43, H 5.19, N 5.96.
bromide (0.065 g, 0.26 mmol). Yield: 92 mg. 1H NMR
(CD2Cl2) d: 1.40 [s, 18H, t-Bu], 1.52 [s, 6H, 2J(PtH) =
2
69 Hz, MePt], 2.74 [s, 2H, J(PtH) = 99 Hz, CH2Pt], 6.17
3
3
[d, 2H, J(HH) = 5 Hz, py-H3,5], 7.47 [d, 2H, J(HH) =
5 Hz, py-H2,6], 7.74 [d, 2H, J(HH) = 6 Hz, bipy-H5], 7.94
3
[s, 2H, bipy-H3], 8.54 [d, 2H, J(HH) = 6 Hz, bipy-H6]. ESI-
3
MS m/z: 585 (7) [PtMe2(bu2bipy)(4-CH2py)]+, 666 (47)
[PtBrMe2(bu2bipy)(4-CH2pyH)]+, 1250 (100) [[PtMe2(-
[PtBrMe2(3-CH2C6H4CN)(DPK)], 4
bu2bipy)(4-CH2py)]+ Br–]+. Anal. calcd. for C26H36BrN3Pt
This was prepared similarly from [PtMe2(DPK)] (0.149 g,
0.36 mmol) and a-bromo-m-tolunitrile (0.080 g, 0.41 mmol).
Yield: 0.162 g (74%). IR (cm–1): n(CN) 2226 , n(CO) 1677.
2
(%): C 46.92, H 5.45, N 6.31; found: C 46.87, H 5.19, N
6.10.
1H NMR (CD2Cl2) d: 1.35 [s, 6H, J(PtH) = 70 Hz, MePt],
2
2
3
[PtBrMe2(CH2-4-C6H4CO2H)(DPK)], 9
3.14 [s, 2H, J(PtH) = 96 Hz, CH2Pt], 6.93 [d, 1H, J(HH) =
7 Hz, C6H4-H6], 6.97 [s, 1H, C6H4-H2], 7.01 [dd, 1H,
3J(HH) = 7 Hz, 3J(HH) = 6 Hz, C6H4-H5], 7.28 [d, 1H,
To a solution of [PtMe2(DPK)] (0.25 g, 0.61 mmol) in
Et2O (10 mL) was added a solution of 4-(bromomethyl)ben-
zoic acid (0.17 g, 0.79 mmol) in Et2O (50 mL). After 1 h,
the solvent was evaporated and the product was recrystal-
3J(HH) = 6 Hz, C6H4-H4], 7.58 [dd, 2H, J(HH) = 7 Hz,
3
3J(HH) = 8 Hz, J(HH) = 2 Hz, bipy-H5], 8.12 [dd, 2H,
4
3J(HH) = 8 Hz, 4J(HH) = 2 Hz, bipy-H4], 8.22 [d, 2H,
3J(HH) = 8 Hz, 4J(HH) = 2 Hz, bipy-H3], 8.52 [d, 2H,
1
lized from CH2Cl2/pentane. Yield: 0.38 g (91%). H NMR
3
(acetone-d6) d: 1.36 [s, 6H, J(PtH) = 71 Hz, MePt], 3.29 [s,
3J(HH) = 7 Hz, J(HH) = 2 Hz, bipy-H6]. Anal. calcd. for
4
3
3
2H, J(PtH) = 95 Hz, CH2Pt], 6.84 [d, 2H, J(HH) = 8 Hz,
C6H4-H2], 7.50 [d, 2H, J(HH) = 8 Hz, C6H4-H3], 7.73 [m,
3
C21H20BrN3PtO (%): C 41.66, H 3.33, N 6.94; found: C
41.34, H 3.02, N 6.60.
2H, DPK-H5], 8.25 [m, 4H, DPK-H3,4], 8.61 [m, 2H, DPK-
H6].
ESI-MS
m/z:
544
(100)
[PtMe2(CH2-4-
C6H4CO2H)(DPK)]+. Anal. calcd. for C21H21BrN2O3Pt (%):
C 40.40, H 3.39, N 4.49; found: C 40.10, H 3.08, N 4.12.
[PtBrMe2(2-CH2C5H4N)(bu2bipy)], 5
To a solution of [PtMe2(bu2bipy)] (0.205 g, 0.4 mmol) in
CH2Cl2 (4 mL) was added a solution of 2-(bromomethyl)-
pyridine hydrobromide (0.123 g, 0.48 mmol) and excess
NEt3 (2.5 mL) in CH2Cl2 (5 mL). After 10 min, water
(5 mL) was added, the mixture was extracted with CH2Cl2
(3 Â 5 mL), the extracts were dried over anhydrous
MgSO4, filtered, and the solvent was removed under vac-
uum to give the product as a white solid, which was recrys-
tallized from CH2Cl2/pentane. Yield: 197 mg. 1H NMR
(CD2Cl2) d: 1.41 [s, 18H, t-Bu], 1.53 [s, 6H, 2J(PtH) =
[PtBrMe2(CH2-4-C6H4CH2CO2H)(DPK)], 11
To a solution of [PtMe2(DPK)] (0.061 g, 0.149 mmol) in
Et2O (4 mL) was added a solution of 4-(bromomethyl)phe-
nylacetic acid (0.043 g, 0.188 mmol) in Et2O (10 mL). The
solvent was evaporated and the product was recrystallized
from CH2Cl2/pentane. Yield: 0.061 g (91.1%). 1H NMR
3
(acetone-d6) d: 1.36 [s, 6H, J(PtH) = 70 Hz, MePt], 3.19 [s,
3
2H, J(PtH) = 92 Hz, CH2Pt], 3.60 [s, 2H, CCH2], 7.24 [d,
2
3
3
2H, J(HH) = 8 Hz, C6H4-H2], 7.36 [d, 2H, J(HH) = 8 Hz,
C6H4-H3], 7.55 [m, 2H, DPK-H5], 7.95 [m, 4H, DPK-H3,4],
8.76 [m, 2H, DPK-H6]. ESI-MS m/z: 558 (100)
[PtMe2(CH2-4-C6H4CH2CO2H)(DPK)]+. The cis isomer was
identified by its 1H NMR spectrum d: 0.99 [s, 3H,
69 Hz, MePt], 2.97 [s, 2H, J(PtH) = 99 Hz, CH2Pt], 6.56
[m, 1H, 3J(HH) = 7 Hz, py-H5], 6.69 [d, 1H, 3J(HH) =
7 Hz, py-H3], 7.06 [m, 1H, J(HH) = 7 Hz, py-H4], 7.40 [d,
3
3
4
2H, J(HH) = 6 Hz, bipy-H5], 7.58 [m, 1H, J(HH) = 2 Hz,
py-H6], 7.94 [s, 2H, bipy-H3], 8.51 [d, 2H, J(HH) = 6 Hz,
3
bipy-H6]. ESI-MS m/z: 585 (100) [PtMe2(bu2bipy)(2-
CH2py)]+. Anal. calcd. for C26H36BrN3Pt (%): C 46.92, H
5.45, N 6.31; found: C 46.48, H 5.07, N 6.04.
2J(PtH) = 71 Hz, Mea], 1.62 [s, 3H, J(PtH) = 72 Hz, Meb],
2
2.81 [d, lH, J(HaHb) = 9 Hz, J(PtHa) = 78 Hz, PtCHa],
2
2
2
3.35, 3.48 [m, 2H, J(HH) = 14 Hz, CCH2], 3.65 [d, lH,
2J(HaHb) = 9 Hz, J(PtHb) = 98 Hz, PtCHb]. Anal. calcd.
2
[PtBrMe2(3-CH2C5H4N)(bu2bipy)], 6
for C22H23BrN2O3Pt (%): C 41.39, H 3.63, N 4.39; found:
C 41.18, H 3.53, N 4.34.
This was prepared similarly from [PtMe2(bu2bipy)]
(0.205 g, 0.4 mmol) and 3-(bromomethyl)pyridine hydrobro-
mide (0.123 g, 0.48 mmol). Yield: 110 mg. 1H NMR
(CD2Cl2) d: 1.42 [s, 18H, t-Bu], 1.50 [s, 6H, 2J(PtH) =
[PtBrMe2(4-CH2C5H4NH)(bu2bipy)]OTf, 12/13
This was prepared in situ by addition of triflic acid (5
2
1
68 Hz, MePt], 2.74 [s, 2H, J(PtH) = 95 Hz, CH2Pt], 6.54
equiv.) to a solution of complex 7 in CD2Cl2. 12: H NMR
[dd, 1H, J(HH) = 7.5 Hz, J(HH) = 5 Hz, py-H5], 6.77 [d,
3
3
2
(CD2Cl2) d: 1.56 [s, 6H, J(PtH) = 68 Hz, MePt], 3.07 [s,
3
1H, J(HH) = 7.5 Hz, py-H4], 7.41 [s, 1H, py-H2], 7.45 [d,
2
1
2H, J(PtH) = 106 Hz, CH2Pt]. 13: H NMR (CD2Cl2) d:
3
3
2H, J(HH) = 6 Hz, bipy-H5], 7.90 [m, 1H, J(HH) = 5 Hz,
2
2
0.78 [s, 3H, J(PtH) = 72 Hz, MePt], 1.03 [s, 3H, J(PtH) =
py-H6], 7.93 [s, 2H, bipy-H3], 8.56 [d, 2H, J(HH) = 6 Hz,
3
67 Hz, MePt], 3.54 [ms, 1H, 2J(HH) = 7 Hz, 2J(PtH) =
bipy-H6]. ESI-MS m/z: 585.2 (27) [PtMe2(bu2bipy)(3-
78 Hz, PtCHaHb], 4.40 [m, 2H, J(PtH) = 110 Hz, PtCHaHb].
2
CH2py)]+; 1250.4 (100) [[PtMe2(bu2bipy)(3-CH2py)]+ Br–]+.
ESI-MS m/z: 666 (100) [PtBrMe2(4-CH2py-H+) (bu2bipy)].
2
Anal. calcd. for C26H36BrN3Pt (%): C 46.92, H 5.45, N
6.31; found: C 46.71, H 5.22, N 6.08.
Similarly prepared were the following
[PtBrMe2(4-CH2C5H4N)(bu2bipy)], 7
This was prepared similarly from [PtMe2(bu2bipy)]
(0.106 g, 0.22 mmol) and 4-(bromomethyl)pyridine hydro-
[PtBrMe2(2-CH2C5H4NH)(bu2bipy)]OTf
2
1H NMR (CD2Cl2, trans isomer) d: 1.68 [s, 6H, J(PtH) =
2
72 Hz, MePt], 3.75 [s, 2H, J(PtH) = 115 Hz, CH2Pt]. ESI-
Published by NRC Research Press

Au et al.
913
MS m/z: 585 (100) [PtMe2(2-CH2py) (bu2bipy)]+, 666 (11)
mixture was stirred for 20 min, decolorizing charcoal was
added, the solution was filtered, and the solvent was re-
moved under vacuum to give a pale yellow solid, which
was recrystallized from CH2Cl2/pentane. Yield: 0.033 g. IR
[PtBrMe2(2-CH2py-H+) (bu2bipy)].
[PtBrMe2(3-CH2C5H4NH)(bu2bipy)]OTf
2
1H NMR (CD2Cl2, trans isomer) d: 1.71 [s, 6H, J(PtH) =
1
(cm–1): n(OH) 3250, n(CN) 2250, n(C=O) absent. H NMR
2
2
75 Hz, MePt], 3.26 [s, 2H, J(PtH) = 102 Hz, CH2Pt]. ESI-
(CD2Cl2) d: 1.18 [s, 3H, J(PtH) = 72 Hz, MePt], 1.48 [s,
MS m/z: 585 (100) [PtMe2(3-CH2py) (bu2bipy)]+, 666 (10)
2
2
3H, J(PtH) = 81 Hz, MePt], 3.03 [d, 1H, J(PtH) = 73 Hz,
[PtBrMe2(3-CH2py-H+) (bu2bipy)].
2J(HH) = 10 Hz, CH2Pt], 3.55 [d, 1H, J(PtH) = 103 Hz,
2
2J(HH) = 10 Hz, CH2Pt], 7.08 [t, 1H, J(HH) = 8 Hz, C6H4-
3
H5], 7.24 [d, 1H, J(HH) = 6 Hz, C6H4-H4], 7.25 [s, 1H,
3
[PtMe2(bu2bipy)(2-CH2py)]OTf, 15ÁOTf
C6H4-H2], 7.30 [m, 1H, J(HH) = 6 Hz, bipy-H5’], 7.34 [d,
3
To a solution of [PtBrMe2(2-CH2py)(bu2bipy)] (0.0524 g,
0.08 mmol) in CH2Cl2 (6 mL) was added a solution of
AgOTf (0.0442 g, 0.17 mmol) in acetone (2 mL). The mix-
ture was stirred for 20 min, decolorizing charcoal was
added, the solution was filtered, and the solvent was evapo-
rated to give the product as a pale yellow solid. Yield:
0.046 g. 1H NMR (CD2Cl2 at –10 8C) d: 0.56 [s, 3H,
2J(PtH) = 69 Hz, MePt], 1.43, 1.44 [s, 18H, t-Bu], 1.85 [s,
3
3
1H, J(HH) = 8 Hz, C6H4-H6], 7.57 [t, 1H, J(HH) = 7 Hz,
bipy-H5], 7.78 [d, 1H, J(HH) = 5 Hz, bipy-H3’], 8.02 [m,
3
3
3
1H, J(HH) = 7 Hz, bipy-H3], 8.03 [m, 1H, J(HH) = 5 Hz,
bipy-H4’], 8.05 [m, 1H, bipy-H4], 8.08 [d, 1H, 3J(HH) =
8 Hz bipy-H6’], 8.44 [d, 1H, J(HH) = 6 Hz bipy-H6]. ESI-
3
MS m/z: 495 (100) [Pt(DPK)(3-CH2C6H4CN)]+, 525 (66)
[PtMe2(DPK)(3-CH2C6H4CN)]+, 543 (16) [PtMe2(DPK)(3-
CH2C6H4CN) + H2O]+. Anal. calcd. for C22H22F3N3O5PtS
(%): C 38.15, H 3.20, N 6.07; found: C 37.90, H 3.29, N
5.77.
2
2
3H, J(PtH) = 69 Hz, MePt], 2.53, 2.62 [m, 2H, J(PtH) =
99 Hz, CHaHbPt], 6.95–8.95 [m, 10H, py, bipy]. ESI-MS m/
z: 585 (100) [PtMe2(bu2bipy)(2-CH2py)]+. Anal. ca1cd. for
C27H36F3N3O3PtS (%): C 44.14, H 4.94, N 5.72; found: C
43.76, H 5.13, N 5.41.
[PtMe2(4-CH2C6H4CH2CO2H)(DPK-OH2)][CF3CO2],
19ÁO2CCF3
To a solution of [PtBrMe2(4-CH2C6H4CH2CO2H)(DPK)]
(0.050 g, 0.0783 mmol) in Et2O (15 mL) was added a solu-
tion of AgO2CCF3 (0.018 g, 0.0815 mmol) in THF (2 mL).
The mixture was stirred for 30 min, decolorizing charcoal
was added, the mixture was filtered, and the solvent was
evaporated to give a yellow solid, which was recrystallized
from ether/pentane. 1H NMR (CD2Cl2) d: 1.05 [s, 3H,
[{PtMe2(bu2bipy)(3-CH2py)}n]OTfn, 16ÁOTf
This was prepared similarly from [PtBrMe2(3-CH2py)(bu2-
bipy)] (0.051 g, 0.08 mmol) and AgOTf (0.047 g,
0.18 mmol). Yield: 0.041 g. ESI-MS m/z: 585 (100)
[PtMe2(3-CH2py)(bu2bipy)]+, 1319 (23) [{PtMe2(bu2bipy)(3-
CH2py)}2OTf]+. Anal. ca1cd. for C27H36F3N3O3PtS (%): C
44.14, H 4.94, N 5.72; found: C 43.68, H 5.02, N 5.36.
2
2J(PtH) = 71 Hz, MeaPt], 1.34 [s, 3H, J(PtH) = 71 Hz,
2
2
MebPt], 2.80 [d, lH, J(HaHb) = 10 Hz, J(PtHa) = 88 Hz,
[{PtMe2(bu2bipy)(4-CH2py)}n]OTfn
CHaPt], 3.44, 3.47 [m, 2H, CCH2], 3.65 [d, lH, J(HaHb) =
2
This was prepared similarly from [PtBrMe2(4-CH2py)(bu2-
bipy)] (0.0498 g, 0.075 mmol) and AgOTf (0.040 g,
0.16 mmol). Yield: 0.030 g. ESI-MS m/z: 585 (100)
[PtMe2(bu2bipy)(4-CH2py)]+, 1319 (4) [PtMe2(bu2bipy)(4-
10 Hz, J(PtHb) = 95 Hz, CHbPt], 6.74 [d, 2H, J(HH) =
8 Hz, C6H4-H3], 6.92 [d, 2H, C6H4-H2], 7.20–8.33 [m, 8H,
DPK]. ESI-MS (M = [PtMe2(4-CH2C6H4CH2CO2H)(DPK-
OH2)][CF3CO2]) m/z: 1151 (5) [2M-2CF3CO2-H3O]+, 1133
(7)[2M-2CF3CO2-H3O]+, 1115(5) [2M-2CF3CO2-2H2O-H)]+,
2
3
CH2py)]+ OTf–]+,
1027
(5)
[PtMe2(bu2bipy)(4-
2
CH2py)]+ OTf–]2+. Anal. ca1cd. for C27H36F3N3O3PtS (%): C
3
576 (100) [M-CF3CO2] , 558 (94) [M-CF3CO2-H2O]+. The
+
44.14, H 4.94, N 5.72; found: C 43.90, H 5.13, N 5.30.
trans isomer was identified by its 1H NMR spectrum d:
1.13 [s, 6H, 2J(PtH) = 71 Hz, MePt], 3.39 [s, 2H,
2J(PtH) = 91 Hz, CH2Pt], 3.51 [s, 2H, CCH2]. Anal. calcd.
for C24H25F3N2O6Pt (%): C 41.80, H 3.65, N 4.06; found:
C 41.56, H 3.87, N 3.81.
[PtMe2(CH2-4-C6H4COOH)(bu2bipy)(OH2)][BF4], 17ÁBF4
A solution of AgBF4 (10.5 mg, 0.054 mmol) in acetone
(5 mL) was added dropwise to complex 11 (38.5 mg,
0.054 mmol) in acetone (10 mL) and allowed to stir for
1 h. AgBr began to precipitate and the mixture was filtered
through Celite. After 2 h of stirring at room temperature, the
solvent was evaporated. The product was washed with pen-
X-ray structure determinations
A crystal was mounted on a glass fibre and data were col-
lected using a Nonius Kappa CCD diffractometer. Details of
the data collection, absorption correction, and structure refine-
ment are given in Table 1 and in the Supplementary data.
Nonhydrogen atoms were refined with anisotropic thermal pa-
rameters, except in cases of disorder. The hydrogen atom po-
sitions were calculated geometrically and were included as
riding on their respective heavy atoms. Brief comments on un-
usual features of individual structures are given below. The
accuracy of bond distances was low in some cases as a result
of disorder, but the structures are all well-defined.
1
tane to give a white solid. Yield: 35.0 mg (88%). H NMR
2
(acetone-d6) d: 1.33 [s, br, 6H, J(PtH) = 64 Hz, MePt], 1.41
2
[s, 18H, t-Bu], 2.38 [s, 2H, J(PtH) = 94 Hz, CH2Pt], 3.19
[s, br, 2H, PtOH2], 6.52 [br, 2H, C6H4(H2, H6)], 7.26 [br,
2H, C6H4(H3, H5)], 7.79 [br, 2H, bipy(H5, H5’)], 8.55 [br,
2H, bipy(H3, H3’)], 8.74 [br, 2H, bipy(H6, H6’)]. Anal calcd.
for C28H39BF4N2O3PtÁMe2CO (%): C 47.04, H 5.73, N 3.54;
found: C 47.11, H 5.76, N 3.42.
[PtMe2(3-CH2C6H4CN)(DPK-OH2)]OTf, 18ÁOTf
To
a
solution of [PtBrMe2(DPK)(3-CH2C6H4CN)]
(0.056 g, 0.09 mmol) in CH2Cl2 (6 mL) was added a solu-
tion of AgOTf (0.026 g, 0.1 mmol) in acetone (2 mL). The
Published by NRC Research Press

Table 1. Crystal data and structure refinement.
Complex
Formula
Fw
3
5
8
10
12/14Á CHCl3
C27H38Br0.36Cl4.64N3Pt
792.95
17Á 1.5Me2COÁ0.5C6H14
C35.H48BF4N2O4.5Pt
856.66
19ÁO2CCF3
C23H23F3N2O6Pt
675.52
C28H36BrN3Pt
689.60
C26H36BrN3Pt
665.58
C28H37BrN2O2Pt
708.60
C29H39BrN2O2Pt
722.62
T (K)
150(2)
150(2)
150(2)
298(2)
295(2)
150(2)
100(2)
l
0.71073
Orthorhombic
Pbca
0.71073
Monoclinic
P21/c
0.71073
Monoclinic
P21/n
0.71073
Orthorhombic
Pbca
0.71073
Monoclinic
P21/c
0.71073
Tetragonal
P-421c
0.71073
Triclinic
P-1
Cryst. syst.
Sp. Gp.
Cell dimensions
˚
a (A)
22.9401(8)
20.2766(6)
11.4773(4)
90
90
90
5338.6(3)
8
1.716
12.7645(3)
11.5506(3)
35.2208(9)
90
93.674(1)
90
5182.2(2)
8
1.706
6.975
50713
9150/0/559
1.043
7.1812(4)
12.7284(7)
30.2139(17)
90
93.785(2)
90
2755.7(3)
4
1.708
6.568
12865
4155/288/309
1.079
22.6325(3)
21.5949(3)
12.0756(2)
90
90
90
5901.9(1)
8
1.627
12.1138(5)
21.932(1)
12.1444(6)
90
91.870(4)
90
3224.8(3)
4
1.633
5.202
26097
5675/283/337
1.255
26.7467(3)
26.7467(3)
10.9285(2)
90
90
90
7818.1(2)
8
1.456
7.8246(5)
17.515(1)
17.683(1)
87.580(4)
85.829(4)
86.391(4)
2410.5(3)
4
1.861
5.885
16428
9418/596/632
1.095
˚
b (A)
˚
c (A)
a
b
g
3
˚
V (A )
Z
Dcalcd. (Mg m–3)
m (mm–1)
Reflns.
Data/restr./param.
Gof
6.774
6.135
3.647
46409
4719/279/306
1.127
61611
5208/244/291
1.412
76143
6867/29/461
1.024
R1 (I>2s(I))
wR2 (all data)
0.058
0.095
0.062
0.167
0.065
0.160
0.092
0.223
0.137
0.313
0.037
0.099
0.066
0.175

Au et al.
915
[PtBrMe2(3-CH2C6H4CN)(bu2bipy)], 3
There was minor unresolved disorder of the t-butyl
groups.
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Supplementary data
Supplementary data for this article are available on the
journal Web site (canjchem.nrc.ca) or may be purchased
from the Depository of Unpublished Data, Document Deliv-
ery, CISTI, National Research Council Canada, Ottawa, ON
K1A 0R6, Canada. DUD 3933. For more information on ob-
taining material, refer to cisti-icist.nrc-cnrc.gc.ca/cms/
unpub_e.shtml. CCDC 711234–711240 contain the X-ray
data in CIF format for seven complexes for this manuscript.
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, Cambridge
CB2 1EZ, UK; fax +44 1223 336033; or deposit@ccdc.
cam.ac.uk).
Acknowledgement
We thank the Natural Sciences and Engineering Research
Council of Canada (NSERC) for financial support.
Published by NRC Research Press

916
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Published by NRC Research Press