Synthesis and redistribution reactions of asymmetric σ-arylplatinum(II) complexes containing 4,7-phenanthroline

Article abstract of DOI:10.1016/j.jorganchem.2004.01.027

The mononuclear σ-aryl complexes of the type trans -[Pt(σ -C₆H₄R)(4,7-phen)(PPh₃)₂] OTf (R=4-CO₂Si^tBuPh₂, 4-CONHMe, 3-CO₂Si^tBuPh₂, 3-CONHMe; OTf=trifluoromethanesulfonate) containing a monodentate 4,7-phenanthroline (4,7-phen) ligand were prepared by an oxidative addition reaction of an aryl iodide with Pt(PPh₃) ₄ to yield the key iodoplatinum(II) precursors trans -[PtI(σ-C₆H₄R)(PPh₃) ₂], followed by halogen metathesis with one equivalent of 4,7-phen. The reaction of trans -[Pt(σ-C₆ H₄R)(4,7-phen)(PPh₃)₂]OTf with labile complexes of the type trans -[Pt(OTf)L₂(σ -C₆H₄R′)] (L=PEt₃, R′=H; L=PPh₃, R′=4-CO₂Si^tBuPh₂ 3-CO₂Si^tBuPh₂, 3-CONHMe) afforded the asymmetric dinuclear complexes of the type trans -[Pt(σ -C₆H₄R)L₂(μ-4,7-phen)Pt(σ -C₆H₄R′) L′₂](OTf) ₂ (L=PPh₃, R=4-CO₂Si^tBuPh₂, L′=PEt₃, R′=H; L=L′=PPh₃, R=4-CONHMe, R′ =4-CO₂Si^tBuPh₂; R=4-CO₂Si^tBuPh₂, R′=3-CONHMe; R=3-CONHMe, R′=3 -CO₂Si^tBuPh₂) in which the 4,7-phen acts as a bridging bidentate ligand. The novel dinuclear species undergo an unusual redistribution reaction that is essentially thermoneutral at 298 K. The exchange process involves facile cleavage of a Pt-N bond and the rapid exchange of trans -[PtL₂(σ-aryl)] units in the equilibrium mixture.

Full text of DOI:10.1016/j.jorganchem.2004.01.027

Journal of Organometallic Chemistry 689 (2004) 1288–1294
www.elsevier.com/locate/jorganchem
Synthesis and redistribution reactions of asymmetric
r-arylplatinum(II) complexes containing 4,7-phenanthroline
b
David P. Gallasch , Susan L. Woodhouse , Louis M. Rendina
b
a,
*
a
School of Chemistry, The University of Sydney, Sydney, NSW 2006, Australia
b
Department of Chemistry, The University of Adelaide, Adelaide, SA 5005, Australia
Received 15 December 2003; accepted 28 January 2004
Abstract
The mononuclear r-aryl complexes of the type trans-[Pt(r-C6H4R)(4,7-phen)(PPh3)2]OTf (R ¼ 4-CO2SitBuPh2, 4-CONHMe, 3-
CO2SitBuPh2, 3-CONHMe; OTf ¼ trifluoromethanesulfonate) containing a monodentate 4,7-phenanthroline (4,7-phen) ligand were
prepared by an oxidative addition reaction of an aryl iodide with Pt(PPh3)4 to yield the key iodoplatinum(II) precursors trans-
[PtI(r-C6H4R)(PPh3)2], followed by halogen metathesis with one equivalent of 4,7-phen. The reaction of trans-[Pt(r-C6H4R)(4,7-
phen)(PPh3)2]OTf with labile complexes of the type trans-[Pt(OTf)L2(r-C6H4R0)] (L ¼ PEt3, R0 ¼ H; L ¼ PPh3, R0 ¼
4-CO2SitBuPh2, 3-CO2SitBuPh2, 3-CONHMe) afforded the asymmetric dinuclear complexes of the type trans-[Pt(r-C6H4R)L2(l-
4,7-phen)Pt(r-C6H4R0)L02](OTf)
(L ¼ PPh3, R ¼ 4-CO2SitBuPh2, L0 ¼ PEt3, R0 ¼ H; L ¼ L0 ¼ PPh3, R ¼ 4-CONHMe, R0 ¼
2
4-CO2SitBuPh2; R ¼ 4-CO2SitBuPh2, R0 ¼ 3-CONHMe; R ¼ 3-CONHMe, R0 ¼ 3-CO2SitBuPh2) in which the 4,7-phen acts as a
bridging bidentate ligand. The novel dinuclear species undergo an unusual redistribution reaction that is essentially thermoneutral at
298 K. The exchange process involves facile cleavage of a Pt–N bond and the rapid exchange of trans-[PtL2(r-aryl)] units in the
equilibrium mixture.
Ó 2004 Elsevier B.V. All rights reserved.
Keywords: 4,7-Phenanthroline; Platinum(II) complex; r-Aryl ligand; Redistribution reaction; NMR Spectroscopy
1. Introduction
These systems represent remarkably unusual examples
of a diimine undergoing second-sphere N...H–O–M in-
teractions in preference to metal complexation.
Diimine ligands are versatile subunits in the con-
struction of supramolecular polygons and polyhedra
using the metal–ligand paradigm (for recent reviews, see
[1–9]). 4,7-Phenanthroline (4,7-phen) is a rigid N-donor
ligand with a 60° directing angle that favours coordi-
nation to transition metals in a bridging bidentate
manner rather than chelation. Recently, it has been used
in the synthesis of a variety of coordination polymers
[10–17], the majority of which contain copper(I), and in
the supramolecular assembly of discrete polygons, e.g., a
cyclic nanostructure comprising of six palladium(II)
ions [18]. 4,7-Phen has also proved useful in the for-
mation of supramolecular H-bonded networks con-
taining hydrated first-row transition metal ions [19,20].
In an exploration of new classes of platinum com-
plexes that possess various H-bonding functionalities for
potential use as building blocks in supramolecular as-
sembly [21,22], we have recently reported the synthesis
of dinuclear organoplatinum(II) complexes that are
bridged by various N-donor ligands including 4,7-phen,
4,40-bipyridine, and bis(4-pyridyl)ketone [23]. Their
preparation involved a novel protection–deprotection
strategy that was successfully used to incorporate two
carboxylic acid groups into the complexes that had the
potential to direct the assembly of such entities into
discrete nanostructures by intermolecular H-bonding.
However, in all cases the complexes possessed C2 sym-
metry and both of the N-donor ligands bearing the
carboxylic acid group, e.g., nicotinic acid, were identi-
cal. Indeed, all attempted preparations of analogous
asymmetric complexes in which the two H-bonding
* Corresponding author. Tel.: +61-2-9351-4781 fax: +61-2-9351-
3329.
E-mail address: rendina@chem.usyd.edu.au (L.M. Rendina).
0022-328X/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2004.01.027

D.P. Gallasch et al. / Journal of Organometallic Chemistry 689 (2004) 1288–1294
1289
functionalities were different proved to be unsuccessful
by this route.
The assignment of the aromatic proton resonances in
9–12 was facilitated by 2D-COSY and 2D-ROESY
NMR experiments. The latter experiments were per-
formed in order to unambiguously assign some of the
protons in the 4,7-phen ligand, where the PPh3 protons
showed distinct cross-peaks to the H3 and H5 protons of
4,7-phen. 2D-COSY NMR spectroscopy experiments
allowed the assignment of the remaining 4,7-phen pro-
tons. The 31P{1H} NMR spectra of 9–12 display a sin-
glet resonance that is flanked by 195Pt satellite signals at
ca. d 19 (1JPPt ¼ ca. 3000 Hz), values that are consistent
with the presence of mutually trans-PPh3 ligands about
a r-arylplatinum(II) centre [21–24].
Herein, we report the synthesis and characterisation
of novel mono- and di-nuclear r-arylplatinum(II)
complexes containing the 4,7-phen ligand. Notably, the
diimine ligand is capable of coordinating to the metal
centre in a monodentate manner, and the synthesis of
asymmetric, dinuclear organoplatinum(II) complexes
bearing H-bonding functionalities such as carboxylic
acids and N-methyl amides can be realised by the ad-
dition of a second metal fragment to the mononuclear
species. Furthermore, we report an unusual redistribu-
tion reaction involving the dinuclear complexes which
proceeds by a facile exchange of the 4,7-phen ligand
between metal centres.
2.2. Synthesis of asymmetric dinuclear complexes con-
taining the 4,7-phen ligand
2. Results and discussion
Treatment of complexes of the type trans-[PtIL2(r-
C6H4R0)] (L ¼ PEt3, R0 ¼ H; L ¼ PPh3, R0 ¼ 4-CO2SitBu
Ph2, 3-CO2SitBuPh2, 3-CONHMe) with one equivalent
of AgOTf in CH2Cl2 solution afforded the correspond-
ing, labile triflato species trans-[Pt(OTf)L2(r-C6H4R0)].
Its reaction with one equivalent of the 4,7-phen com-
plexes 9–12 resulted in a rapid formation of the asym-
metric, dinuclear species 13–16 (Scheme 2). As described
above for the mononuclear complexes 9–12, 2D-COSY
and ROESY NMR experiments were performed with
13–16 in order to confirm the assignment of the 4,7-phen
ring protons. In addition, the PEt3 protons in 13 showed
distinct cross-peaks with the H6 and H8 protons in the
2D-ROESY NMR spectrum.
The 31P{1H} NMR spectra of 13–16 display two
singlet resonances that are each flanked by 195Pt satellite
signals. For example, in 13 the PPh3 and PEt3 reso-
nances appear at distinct chemical shifts (d 19.4 and d
11.5, respectively). The chemical shift of the PEt3 reso-
nance and the magnitude of the Pt–P coupling constant
(ca. 2733 Hz) are comparable to those reported for other
r-arylplatinum(II) complexes with mutually trans-PEt3
ligands [21,25].
2.1. Synthesis of complexes containing a monodentate 4,7-
phen ligand
The r-aryl(iodo)platinum(II) precursor complexes 5–8
containing either a silyl-protected carboxylic acid or a N-
methyl amide functionality were readily prepared by an
oxidative addition reaction involving a suitably-func-
tionalised aryl iodide 1–4 with Pt(PPh3)4 (Scheme 1). As
reported previously [23], protection of the carboxylic acid
functionality in the aryl iodides 1 and 2 as a tert-bu-
tyl(diphenylsilyl) ester was found to be necessary in order
to obtain the desired r-arylplatinum(II) product in a re-
producible, high yield whereas protection of the amide
functionality in 3 and 4 proved unnecessary.
Treatment of the iodo complexes 5–8 with one
equivalent of AgOTf followed by the addition of one
equivalent of 4,7-phen in CH2Cl2 solution afforded a
kinetic mixture containing both the mononuclear and
corresponding dinuclear species in which the N-donor
ligand coordinates to the platinum(II) centre in a
monodentate and bridging bidentate manner, respec-
tively. When the solution was left to stand for ca. 48 h at
room temperature, the mononuclear platinum(II) de-
rivatives 9–12 were formed exclusively under thermo-
dynamic control.
The addition of HOTf to 13–16 resulted in the facile
cleavage of the silyl-protecting group to afford the cor-
responding carboxylic acid derivatives as described
Scheme 1.

1290
D.P. Gallasch et al. / Journal of Organometallic Chemistry 689 (2004) 1288–1294
Scheme 2.
previously [23], but their isolation proved difficult owing
to a redistribution reaction that is described as follows.
2.3. Redistribution reactions involving 13–16
Redistribution reactions in platinum(II) chemistry
are well known, and all involve the transfer of a halogen,
alkyl or aryl group between metal centres [26–29]. The
dinuclear complexes 13–16 were found to undergo an
unusual redistribution in CH2Cl2 solution to afford an
equilibrium mixture of the asymmetric and two sym-
metrical dinuclear components. For example, when 13
was left to stand in CH2Cl2 solution for several hours at
298 K, it equilibrated with the symmetrical species 17
and 18 (Scheme 3). The identities of each component in
the equilibrium mixture were confirmed by 1H and
31P{1H} NMR spectroscopy. For example, four distinct
resonances at
d
21.7 (1JPPt ¼ 3002 Hz),
d 21.1
(1JPPt ¼ 2962 Hz), d 15.3 (1JPPt ¼ 2674 Hz), and d 14.7
(1JPPt ¼ 2696 Hz) were observed in the 31P{1H} NMR
spectrum. The resonances at d 21.1 and d 14.7 were
assigned to 13, while those at d 21.7 and d 15.3 were
attributed to 17 and 18, respectively. To further confirm
the identity of the components in the equilibrium mix-
ture, 17 and 18 were independently prepared and char-
acterised [23]. Indeed, the addition of one equivalent of
17 to 18 in CH2Cl2 solution resulted in an identical re-
distribution reaction. In all cases, the proportion of
asymmetric species was approximately twice that of each
of the other complexes at equilibrium indicating that the
redistribution reaction is essentially thermoneutral at
298 K. As a statistical distribution of components was
found in these systems, there is no evidence for any
significant steric and electronic effects associated with
the r-aryl or phosphine ligands.
Scheme 3.
One can envisage the redistribution reaction involves
a facile cleavage of either one of the Pt–N bonds in 13–
16 as a consequence of the strong trans effect associated
with the r-aryl group, followed by complexation of the
free N-atom with another Pt unit. It is clear from the
redistribution reaction involving the mixed-phosphine
complex 13 that Pt–C bond cleavage does not occur as
products resulting from a loss of the r-aryl ligand, such
as the PPh3 analogue of 18, are not observed. The
cleavage of only Pt–N bonds during the redistribution
reaction is further supported by ESI-MS experiments
that demonstrate a facile loss of the 4,7-phen ligand
from the complexes, an effect that has been observed

D.P. Gallasch et al. / Journal of Organometallic Chemistry 689 (2004) 1288–1294
1291
previously in related systems containing other types of
N-donor ligands, e.g., nicotinic acid [22,23]. Intermedi-
ate species could not be detected by NMR spectroscopy,
even at low temperatures, indicating that once formed
the labile triflato complex trans-[Pt(OTf)L2(r-C6H4R)]
(L ¼ PEt3, R ¼ H; L ¼ PPh3, R ¼ 4-CO2SitBuPh2) must
rapidly react with the free N-atom of the mononuclear
species trans-[Pt(4,7-phen)L2(r-C6H4R)]. These results
clearly demonstrate that the isolation of the dinuclear
species 13–16 must be completed within a short period
(ca. 1 h) at room temperature or significant amounts of
the symmetrical exchange products are also formed in
the reaction mixture.
ldiphenylsilyl-3-iodobenzoate (1) [23], tert-butyldi-
phenylsilyl-4-iodobenzoate (2) [23], trans-iodo(tert-
butyldiphenylsilylbenzoate-C3)bis(triphenylphosphine)
platinum(II) (5) [23] and trans-iodo(tert-butyldi-
phenylsilylbenzoate-C4)bis(triphenylphosphine)platinum
(II) (6) [23] were prepared according to the literature
procedures.
4.2. N-methyl-3-iodobenzamide (3)
3-Iodobenzoic acid (5.00 g, 0.02 mol) was added to
SOCl2 (25 mL, 0.35 mol) and the mixture was stirred at
room temperature for 18 h to afford a clear solution.
SOCl2 was removed in vacuo, the residual clear orange
oil dried for 30 min, and NH2Me (40% in H2O, 5 mL)
was added dropwise at 10 °C. The reaction mixture was
stirred for 16 h to afford a homogeneous white mixture
which was extracted with CHCl3 (2 ꢀ 20 mL). The or-
ganic extracts were combined, and all volatiles were
removed in vacuo to afford 3 as a cream-coloured solid
3. Conclusion
Novel asymmetric, dinuclear organoplatinum(II)
complexes containing 4,7-phen have been prepared by
the use of a robust intermediate in which the diimine
ligand is coordinated to the metal centre in a monod-
entate manner. Although the use of the dinuclear species
in the construction of H-bonded supramolecular as-
semblies is compromised by an unusual redistribution
reaction, the isolation of the mononuclear complexes of
4,7-phen allows one to explore the possibility of pre-
paring hybrid species in which the free N-atom under-
goes second-sphere H-bonding interactions. We are
currently exploring the chemistry of such systems.
1
(5.0 g, 96%); m.p. 95–97 °C (lit. 105 °C [32]). H NMR
(CDCl3): d 8.23 (s, 1H, H2), 7.93 (d, 1H, 3JHH ¼ 7.5 Hz,
3
H6), 7.85 (d, 1H, JHH ¼ 7.5 Hz, H4), 7.23 (t, 1H,
3JHH ¼ 7.9 Hz, H5), 6.41 (br s, 1H, NH), 3.12 (d, 3H,
3JHH ¼ 4.4 Hz, NMe). Anal. Calc. for C8H8INO: C,
36.81; H, 3.09; N, 5.37. Found: C, 36.81; H, 3.10; N,
5.40%.
4.3. N-methyl-4-iodobenzamide (4)
A solution of 4-iodobenzoic acid (1.02 g, 4.12 mmol) in
SOCl2 (25 mL, 0.34 mol) was stirred for 30 min at room
temperature. CH2Cl2 (30 mL) was added to increase
solubility of the acid and the mixture was heated to reflux
for 1 h until all of the solid had dissolved. CH2Cl2 and
unreacted SOCl2 were removed by distillation, and the
residue was dried in vacuo. The residue was re-dissolved
in CH2Cl2 (30 mL) and NH2Me (40% in H2O, 1 mL) was
added. The mixture was stirred at room temperature for 2
h. The solvent was removed in vacuo, and the crude solid
was extracted with CH2Cl2 (2 ꢀ 50 mL). The combined
extracts were washed with H2O (2 ꢀ 50 mL), dried over
anhydrous MgSO4, and reduced in vacuo to afford 4 (0.99
4. Experimental
4.1. General
All procedures were performed under an inert at-
mosphere of high purity N2 using standard Schlenk
techniques. CH2Cl2 and diethyl ether were distilled from
CaH2 and sodium, respectively. Toluene was pre-dried
over CaSO4, followed by distillation from sodium. All 1-
D NMR spectra were recorded by means of a Varian
Gemini 2000 NMR spectrometer (1H at 300.10 MHz
and 31P at 121.50 MHz). 2-D NMR spectroscopy ex-
periments were performed by means of a Varian Unity
INOVA 600 MHz NMR instrument. Chemical shifts are
reported in ppm with respect to a TMS reference (1H) or
a sealed external standard of 85% H3PO4 (31P). Melting
points were determined using a Kofler hot-stage appa-
ratus under a Reichert microscope, and are uncorrected.
IR spectra were recorded on a Perkin–Elmer FT-IR
1920ꢀ spectrophotometer. Elemental analyses were de-
termined by Chemical and Micro Analytical Services
Pty. Ltd., Vic. (Australia).
1
g, 92%); m.p. 161–162 °C (lit. 165 °C [32]). H NMR
(CDCl3): d 7.77 (d, 2H, 3JHH ¼ 8.1 Hz, H2;6), 7.48 (d, 2H,
3JHH ¼ 8.7 Hz, H3;5), 6.30 (s, 1H, NH), 2.99 (d, 3H,
3JHH ¼ 4.8 Hz, NMe). Anal. Calc. for C8H8INO: C,
36.81; H, 3.09; N, 5.37. Found: C, 36.78; H, 2.98; N,
5.33%.
4.4.
phosphine)platinum(II) (7)
trans-Iodo(N-methylbenzamide-C3)bis(triphenyl-
4,7-Phen and AgOTf were obtained commercially
(Aldrich). Tetrakis(triphenylphosphine)platinum(0) [30],
tetrakis(triethylphosphine)platinum(0) [31], tert-buty-
A solution of 3 (186 mg, 0.71 mmol) in toluene (50
mL) was added to Pt(PPh3)4 (743 mg, 0.60 mmol). The
mixture was stirred at 75 °C for 17 h to afford a white

1292
D.P. Gallasch et al. / Journal of Organometallic Chemistry 689 (2004) 1288–1294
precipitate that was collected by filtration, washed with
n-hexane, and air dried (455 mg, 77%). IR (nujol): 1632
cmꢁ1 m(C@O) cmꢁ1. 1H NMR (CDCl3): d 7.51–7.57 (m,
12H, PPh3), 7.23–7.35 (m, 18H, PPh3), 6.97 (d, 1H,
3JHH ¼ 7.5, 3JPtH ¼ 56.4 Hz, H6), 6.72 (d, 1H, 3JHH ¼ 7.5
4.7. trans-4,7-Phenanthroline(tert-butyldiphenylsilylben-
zoateC4)bis(triphenylphosphine)platinum(II)triflate(10)
Following a similar procedure to that described in
Section 4.6, 6 (360 mg, 0.298 mmol) was treated with
AgOTf (73 mg, 0.284 mmol) to afford the corresponding
triflato complex as a white solid (348 mg). The triflato
complex (100 mg, 8.14 ꢀ 10ꢁ5 mol) was then treated
with 4,7-phen (15.1 mg, 8.38 ꢀ 10ꢁ5 mmol) to afford 10
as a white solid (79 mg, 69%); m.p. >250 °C (dec.). IR
(nujol): 1696 m(C@O), 1279, 1224, 1180, 1154, 1031
3
Hz, H4), 6.67 (s, 1H, JPtH ¼ 57 Hz, H2), 6.24 (t, 1H,
3
3JHH ¼ 7.5 Hz, H5), 4.97 (d, 1H. JHH ¼ 4.5 Hz, NH),
3
2.76 (d, 3H, JHH ¼ 4.5 Hz, NMe). 31P{1H} NMR
1
(CDCl3): d 22.0 (s, JPtP ¼ 3026 Hz). Anal. Calc. for
C44H38INOP2Pt: C, 53.89; H, 3.91; N, 1.43. Found: C,
53.57; H, 3.85; N, 1.45%.
(OTf) cmꢁ1
.
1H NMR (CDCl3): d 9.35 (d, 1H,
3
3JHH ¼ 9.6 Hz, H5), 9.12 (d, 1H, JHH ¼ 5.1 Hz, H3),
4.5. trans-Iodo(N-methylbenzamide-C4)bis(triphenylphos-
phine)platinum(II) (8)
9.08 (d, 1H, 3JHH ¼ 4.2 Hz, H8), 8.91 (d, 1H, 3JHH ¼ 8.4
Hz, H10), 8.83 (d, 1H, JHH ¼ 8.4 Hz, H1), 8.29 (d, 1H,
3
3JHH ¼ 9.3 Hz, H6), 7.77 (dd, 1H, 3JHH ¼ 4.2, 3JHH ¼ 8.4
Following a similar procedure to that described in
Section 4.4, a suspension of 4 (0.50 g, 1.92 mmol) in
toluene (50 mL) was added to Pt(PPh3)4 (1.98 g, 1.59
mmol) to afford a white microcrystalline solid (1.06 g,
Hz, H9), 7.71 (dd, 4H, JHH ¼ 1.5 Hz, JHH ¼ 7.8 Hz,
3
3
SiPh), 7.59 (dd, 1H, JHH ¼ 5.4 Hz, JHH ¼ 8.4 Hz, H2),
3
3
0
0
0
0
7.00–7.50 (m, 40H, PPh3, SiPh, H2 ;3 ;5 ;6 ), 1.13 (s, 9H,
tBu). 31P{1H} NMR (CDCl3): d 19.1 (s, JPtP ¼ 2961
1
1
68%). IR (nujol): 1640 cmꢁ1 m(C@O) cmꢁ1. H NMR
Hz). Anal. Calc. for C72H61F3N2O5P2PtSSi: C, 61.40;
H, 4.37; N, 1.99. Found: C, 61.45; H, 4.24; N, 2.00%.
(CDCl3): d 7.51–7.57 (m, 12H, PPh3), 7.22–7.35 (m,
3
3
18H, PPh3), 6.73 (d, 2H, JHH ¼ 8.1, JPtH ¼ 56.4 Hz,
3
H2;6), 6.50 (d, 2H, JHH ¼ 8.1 Hz, H3;5); 5.62 (d, 1H,
4.8. trans-4,7-Phenanthroline(N-methylbenzamide-C3)
bis(triphenylphosphine)platinum(II) triflate (11)
3JHH ¼ 4.5 Hz, NH), 2.89 (d, 3H, 3JHH ¼ 4.5 Hz, NMe).
1
31P{1H} NMR (CDCl3): d 21.2 (s, JPtP ¼ 3025 Hz).
Anal. Calc. for C44H38INOP2Pt: C, 53.89; H, 3.91; N,
1.43. Found: C, 53.90; H, 3.91; N, 1.38%.
Following a similar procedure to that described in
Section 4.6, 7 (229 mg, 0.233 mmol) was treated with
AgOTf (58.6 mg, 0.228 mmol) to afford the corre-
sponding triflato complex as a pale-yellow solid (228
mg). The triflato complex (148 mg, 1.47 ꢀ 10ꢁ4 mol) was
then treated with 4,7-phen (27 mg, 1.50 ꢀ 10ꢁ4 mol) to
afford 11 as a white solid (133 mg, 76%); m.p. >250 °C
(dec.). IR (nujol): 1655 m(C@O), 1277, 1262, 1225, 1178,
1150, 1030 (OTf) cmꢁ1. 1H NMR (CDCl3): d 9.34 (br s,
4.6. trans-4,7-Phenanthroline(tert-butyldiphenylsilylbenzo-
ate-C3)bis(triphenylphosphine)platinum(II) triflate (9)
To a stirred solution of 5 (360 mg, 0.298 mmol) in
CH2Cl2 (40 mL) was added a solution of AgOTf (73
mg, 0.284 mmol) in distilled acetone (2 mL). The
mixture was stirred for 16 h in the absence of light at
room temperature. AgI was removed by filtration
through a pad of Celite filter aid, and the filtrate was
reduced in vacuo to yield the corresponding triflato
complex as a white solid (348 mg). A solution of the
triflato complex (61 mg, 4.97 ꢀ 10ꢁ5 mol) and 4,7-phen
(10.4 mg, 5.77 ꢀ 10ꢁ5 mol) in CH2Cl2 (30 mL) was
stirred for 48 h. The solvent was removed in vacuo and
the residue was recrystallised twice from CH2Cl2/n-
hexane to afford 9 as a white solid (53 mg, 75%); m.p.
>250 °C (dec.). IR (nujol): 1701 m(C@O), 1277, 1263,
3
1H, H5), 9.33 (br d, 1H, JHH ¼ 7.5 Hz, H3 or 8), 9.07 (d,
3
3
1H, JHH ¼ 3.6 Hz, H1 or 10), 8.77 (d, 1H, JHH ¼ 8.7 Hz,
H1 or 10), 8.61 (br d, 1H, JHH ¼ 7.5 Hz, H3 or 8), 8.31 (br
3
s, 1H, H6), 7.70 (dd, 1H, 3JHH ¼ 4.5 Hz, 3JHH ¼ 8.7 Hz,
0
0
H2 or 9), 7.10–7.50 (m, 33H, PPh3, H4 ;6 ;2 or 9), 7.01 (d,
0
3
3
1H, JHH ¼ 7.2 Hz, H2 ), 6.42 (t, 1H, JHH ¼ 7.5 Hz,
0
H5 ), 6.11 (d, 1H, JHH ¼ 4.8 Hz, NH), 2.90 (d, 3H,
3JHH ¼ 4.8 Hz, NMe). 31P{1H} NMR (CDCl3): d 19.5
3
1
(s, JPtP ¼ 3000 Hz). Anal. Calc. for C57H46F3N2
O4P2PtS: C, 57.87; H, 3.92; N, 3.55. Found: C, 57.74; H,
4.01; N, 3.61%.bb
1
1225, 1179, 1152, 1031 (OTf) cmꢁ1. H NMR (CDCl3):
3
d 9.37 (d, 1H, JHH ¼ 9.3 Hz, H5), 9.08 (dd, 1H,
4.9. trans-4,7-Phenanthroline(N-methylbenzamide-C4)
bis(triphenylphosphine)platinum(II) triflate (12)
3
3JHH ¼ 1.5 Hz, JHH ¼ 4.5 Hz, H3), 9.07 (br s, 1H, H8),
3
8.90 (t, 2H, JHH ¼ 8.4 Hz, H1;10), 8.30 (d, 1H,
3JHH ¼ 9.3 Hz, H6), 7.70–7.80 (m, 6H, H2;9, SiPh),
Following a similar procedure to that described in
Section 4.6, 8 (301 mg, 0.307 mmol) was treated with
AgOTf (75 mg, 0.292 mmol) to afford the corresponding
triflato complex as a pale-yellow solid (293 mg). The
triflato complex (92 mg, 9.17 ꢀ 10ꢁ5 mol) was then
treated with 4,7-phen (18 mg, 10.15 ꢀ 10ꢁ5 mol) to
0
0
0
7.00–7.60 (m, 38H, SiPh, PPh3, H4 ;2 ;6 ), 6.41 (t, 1H,
0
t
3JHH ¼ 7.5 Hz, H5 ), 1.20 (s, 9H, Bu). 31P{1H} NMR
1
(CDCl3): d 19.1 (s, JPtP ¼ 2962 Hz). Anal. Calc. for
C72H61F3N2O5P2PtSSi: C, 61.40; H, 4.37; N, 1.99.
Found: C, 61.34; H, 4.36; N, 1.83%.

D.P. Gallasch et al. / Journal of Organometallic Chemistry 689 (2004) 1288–1294
1293
afford 12 as a white solid (90 mg, 83%); m.p. >250 °C
(dec.). IR (nujol): 1660 m(C@O), 1276, 1260, 1228, 1176,
h at room temperature. The solvent was removed in
vacuo and the residue was recrystallised from CH2Cl2/
diethyl ether to give 14 as a white solid (36 mg, 82%);
m.p. >250 °C (dec.). IR (nujol): 1698, 1620 m(C@O),
1
1150, 1030 (OTf) cmꢁ1. H NMR (CDCl3): d 9.38 (d,
3
3
1H, JHH ¼ 9.3 Hz, H5), 9.15 (d, 1H, JHH ¼ 4.5 Hz,
H3 or 8) 9.08 (d, 1H, JHH ¼ 4.5 Hz, H3 or 8), 8.87 (d, 1H,
1275, 1262, 1228, 1178, 1151, 1033 (OTf) cmꢁ1 1H
.
3
3JHH ¼ 8.4 Hz, H1 or 10), 8.76 (d, 1H, JHH ¼ 8.4 Hz,
NMR (CDCl3): d 10.00 (s, 2H, H5;6), 9.18 (d, 1H,
3
H1 or 10), 8.33 (d, 1H, JHH ¼ 9.3 Hz, H6), 7.74 (dd, 1H,
3JHH ¼ 8.7 Hz, H1 or 10), 9.13 (d, 1H, JHH ¼ 8.4 Hz,
3
3
3JHH ¼ 4.5 Hz, JHH ¼ 8.4 Hz, H9), 7.50 (dd, 1H,
H1 or 10), 8.62 (t, 2H, JHH ¼ 6 Hz, H3;8), 7.71 (d, 4H,
3
3
3JHH ¼ 4.5 Hz, JHH ¼ 8.4 Hz, H2), 7.10–7.40 (m, 30H,
3JHH ¼ 6.9 Hz, SiPh)0, 7.10–7.50 (m, 74H, SiPh,
3
0
0
0
0
0
PPh3), 6.86 (br s, 2H, H2 ;6 ), 6.71 (br d, 2H, JHH ¼ 8.1
PP0h3,H2;9, p-ester H2 ;3 ;5 ;6 ), 6.73 (br m, 2H, p-amide
3
0
0
0
Hz, H3 ;5 ), 5.87 (d, 1H, 3JHH ¼ 4.5 Hz, NH), 2.88 (d, 3H,
3JHH ¼ 4.5 Hz, NMe). 31P{1H} NMR (CDCl3): d 19.1
H3 ;5 ), 5.98 (d, 1H, JHH ¼ 4.5 Hz, NH), 2.88 (d, 3H,
3
3JHH ¼ 4.2 Hz, NMe), 1.17 (s, 9H, Bu). 31P{1H} NMR
t
1
(s, JPtP ¼ 2962 Hz). Anal. Calc. for C57H46F3N2O4
(CDCl3): d 19.9 (s, 1JPtP ¼ 3029 Hz), 19.7 (s, 1JPtP ¼ 3029
Hz). Anal. Calc. for C117H99F6N3O9P4Pt2S2Si: C, 58.28;
H, 4.14; N, 1.74. Found: C, 58.15; H, 4.08; N, 1.82%.
P2PtS: C, 57.87; H, 3.92; N, 3.55. Found: C, 57.72; H,
3.93; N, 3.50%.
4.10. trans-(tert-Butyldiphenylsilylbenzoate-C4)bis(tri-
phenylphosphine)platinum(II)-l-4,7-phenanthroline(r-
phenyl)bis(triethylphosphine)platinum(II) bis(triflate)
(13)
4.12. trans-l-4,7-Phenanthroline(tert-butyldiphenylsilyl-
benzoateC4)(N-methylbenzamide-C3)bis[bis(triphenyl-
phosphine)platinum(II)] bis(triflate) (15)
Following a similar procedure to that described in
Section 4.11, 10 (44 mg, 3.124 ꢀ 10ꢁ5 mol) was treated
with the triflato derivative of 7 prepared in Section 4.8
(31 mg, 3.121 ꢀ 10ꢁ5 mol) to afford 15 as a white solid
(45 mg, 60%); m.p. >250 °C (dec.). IR (nujol): 1696,
1632 m(C@O), 1278, 1260, 1228, 1175, 1149, 1030 (OTf)
cmꢁ1. 1H NMR (CDCl3): d 10.20 (d, 1H, 3JHH ¼ 9.3 Hz,
trans-[PtI(r-C6H5)(PEt3)2] (0.075 g, 0.12 mmol) in
CH2Cl2 (20 mL) was treated with AgOTf (0.030 g, 0.12
mmol) and the mixture was stirred for 16 h in the ab-
sence of light at room temperature. AgI was removed by
filtration through a pad of Celite filter aid, and the fil-
trate was concentrated in vacuo (ca. 5 mL). 10 (0.134 g,
0.11 mmol) was added and the solution was stirred for 1
h at room temperature. The solvent was removed in
vacuo to give 13 as a white solid (0.201 g, 82%); m.p.
>250 °C (dec.). IR (nujol) 1695 m(C@O), 1654, 1637,
1581 (C@C, C@N), 1277, 1263, 1225, 1179, 1152, 1031
3
H5 or 6), 9.77 (d, 1H, JHH ¼ 9.3 Hz, H5 or 6), 9.22 (d, 1H,
3
3JHH ¼ 8.1 Hz, H1 or 10), 9.196 (d, 1H, JHH ¼ 8.1 Hz,
H1 or 10), 8.71 (d, 1H, 3JHH ¼ 5.1 Hz, H3 or 8), 8.43 (d, 1H,
3JHH ¼ 5.1 Hz, H3 or 8), 8.36 (s, 1H, H2 or 9), 8.04 (s, 1H,
H2 or 9), 7.71 (d, 4H, 3JHH ¼ 7.5 Hz, SiPh). 7.10–7.40 (m,
0
0
0
0
0
0
0
(OTf) cmꢁ1
;
1H NMR (CD2Cl2): d 9.77 (d, 1H,
72H, SiPh, PPh3, p-ester H2 ;3 ;5 ;6 , m-amide H2 ;4 ;6 ),
0
3JHH ¼ 9.6 Hz, H5), 9.53 (d, 1H, JHH ¼ 8.4 Hz, H10),
6.67 (s, 1H, m-amide H5 ), 6.01 (m, 1H, NH), 3.18 (d,
3
9.51 (d, 1H, 3JHH ¼ 9.6 Hz, H6), 9.29 (d, 1H, 3JHH ¼ 5.4
3H, JHH ¼ 3.6 Hz, NMe), 1.19 (s, 9H, Bu). 31P{1H}
3
t
3
1
Hz, H8), 9.22 (d, 1H, JHH ¼ 5.4 Hz, H3), 9.17 (d, 1H,
NMR (CDCl3): d 20.4 (s, JPtP ¼ 3005 Hz) 19.9 (s,
3JHH ¼ 8.4 Hz, H1), 8.19 (dd, 1H, JHH ¼ 5.4 Hz,
1JPtP ¼ 3026 Hz). Anal. Calc. for C117H99F6N3O9
P4Pt2S2Si: C, 58.28; H, 4.14; N, 1.74. Found: C, 58.14;
H, 4.08; N, 1.91%.
3
3JHH ¼ 8.4 Hz, H9), 7.87 (m, 1H, PtPh), 7.66–7.64 (m,
3
3
4H, SiPh), 7.56 (dd, 1H, JHH ¼ 5.4 Hz, JHH ¼ 8.4 Hz,
H2), 7.47–6.99 (m, 44H, PPh3, SiPh, PtPh, H12;16
,
H13;15), 1.28–1.02 (m, 30H, PCH2CH3), 1.11 (s, 9H,
tBu); 31P{1H} NMR (CDCl3): d 19.4 (s, 1JPPt ¼ 2996 Hz,
PPh3), 11.5 (s,1JPPt ¼ 2733 Hz, PEt3). 31P{1H} NMR
4.13. trans-l-4,7-Phenanthroline(tert-butyldiphenylsilyl
benzoate-C3)(N-methylbenzamide-C3)bis[bis(triphenyl-
phosphine)platinum(II)] bis(triflate) (16)
1
(CD2Cl2): d 21.1 (s, JPPt ¼ 2969 Hz, PPh3), 14.7
(s,1JPPt ¼ 2698
Hz,
PEt3).
Anal.
Calc.
for
Following a similar procedure to that described in
Section 4.11, 11 (60 mg, 5.06 ꢀ 10ꢁ5 mol) was treated
with the triflato derivative of 5 prepared in Section 4.6
(62 mg, 5.05 ꢀ 10ꢁ5 mol) to afford 16 as a white solid (50
mg, 41%); m.p. >250 °C (dec.). IR (nujol): 1700, 1656
C90H96F6N2O8P4Pt2S2Si: C, 52.63; H, 4.71; N, 1.36.
Found: C, 52.55; H, 4.42; N, 1.52%.
4.11. trans-l-4,7-Phenanthroline(tert-butyldiphenylsilyl-
benzoateC4)(N-methylbenzamide-C4)bis[bis(triphenyl-
phosphine)platinum(II)] bis(triflate) (14)
1
m(C@O), 1275, 1227, 1174, 1150, 1031 (OTf) cmꢁ1. H
3
NMR (CDCl3): d 10.21 (d, 1H, JHH ¼ 9.6 Hz, H5 or 6),
3
9.72 (d, 1H, JHH ¼ 9.6 Hz, H5 or 6), 9.25 (d, 2H,
3
The triflato derivative of 6 was prepared as described
in Section 4.7. To a solution of 12 (21.5 mg, 1.82 ꢀ 10ꢁ5
mol) in CH2Cl2 (25 mL) was added the triflato complex
(22.3 mg, 1.82 ꢀ 10ꢁ5 mol). The mixture was stirred for 1
3JHH ¼ 8.4 Hz, H1;10), 8.74 (br d, 1H, JHH ¼ 5.4 Hz,
H3 or 8), 8.57 (br d, 3JHH ¼ 5.4 Hz, H3 or 8), 8.30 (br s, 1H,
H2 or 9), 8.11 (br d, 1H, 3JHH ¼ 5.4 Hz, H2 or 9), 8.02 (br s,
3
1H, ArH), 7.64 (d, 4H, JHH ¼ 6.3 Hz, SiPh), 6.99–7.50

1294
D.P. Gallasch et al. / Journal of Organometallic Chemistry 689 (2004) 1288–1294
[10] S.A. Barnett, A.J. Blake, N.R. Champness, C. Wilson, Dalton
Trans. (2003) 2387.
(m, 71H, PPh3, SiPh, 5ArH), 6.87 (br s, 1H,0 m- amide
0
3
H5 ), 6.77 (t, 1H, JHH ¼ 7.2 Hz, m-ester H5 ), 6.02 (t,
[11] A.J. Blake, N.R. Brooks, N.R. Champness, P.A. Cooke, M. Crew,
A.M. Deveson, L.R. Hanton, P. Hubberstey, D. Fenske, M.
Schroder, Cryst. Eng. 2 (1999) 181.
3
3
1H, JHH ¼ 6.6 Hz, NH), 3.19 (d, 3H, JHH ¼ 3.6 Hz,
NMe), 1.09 (s, 9H, tBu). 31P{1H} NMR (CDCl3): d 20.3
1
1
(s, JPtP ¼ 3033 Hz), 20.2 (s, JPtP ¼ 3033 Hz). Anal.
Calc. for C117H99F6N3O9P4Pt2S2Si: C, 58.28; H, 4.14;
N, 1.74. Found: C, 58.22; H, 4.07; N, 1.68%.
[12] D. Hagrman, P.J. Zapf, J. Zubieta, Chem. Commun. (1998) 1283.
[13] J.M. Knaust, S. Lopez, C. Inman, S.W. Keller, Polyhedron 22
(2003) 3015.
[14] T. Kromp, W.S. Sheldrick, C. Nather, Z. Anorg. Allg. Chem. 629
(2003) 45.
[15] S. Lopez, S.W. Keller, Cryst. Eng. 2 (1999) 101.
[16] S. Lopez, S.W. Keller, Inorg. Chem. 38 (1999) 1883.
[17] M.-L. Tong, Y.-M. Wu, S.-L. Zheng, X.-M. Chen, T. Yuen, C.-L.
Lin, X. Huang, J. Li, New J. Chem. 25 (2001) 1482.
[18] J.R. Hall, S.J. Loeb, G.K.H. Shimizu, G.P.A. Yap, Angew.
Chem. Int. Ed. 37 (1998) 121.
Acknowledgements
We thank Mr. P. Clements (The University of
Adelaide) for recording the 2D-NMR spectra, Dr. S.M.
Pyke (The University of Adelaide) for useful NMR
discussions, and Ms. S. Thavaneswaran (The University
of Adelaide) for the preparation of 3. We also thank
Johnson Matthey for the generous loan of platinum
salts, and we are grateful to the University of Adelaide
for financial support.
[19] S.A. Barnett, A.J. Blake, N.R. Champness, C. Wilson, J.
Supramol. Chem. 2 (2003) 17.
[20] D.A. Beauchamp, S.J. Loeb, Chem. Eur. J. 8 (2002) 5084.
[21] M.G. Crisp, E.R.T. Tiekink, L.M. Rendina, Inorg. Chem. 42
(2003) 1057.
[22] N.C. Gianneschi, E.R.T. Tiekink, L.M. Rendina, J. Am. Chem.
Soc. 122 (2000) 8474.
[23] D.P. Gallasch, E.R.T. Tiekink, L.M. Rendina, Organometallics
20 (2001) 3373.
[24] P.S. Pregosin, R.W. Kunz, 31P and 13C NMR of Transition Metal
Complexes, Springer, Berlin, 1979.
References
[25] C.J. Kuehl, C.L. Mayne, A.M. Arif, P.J. Stang, Org. Lett. 2 (2000)
3727.
[1] M. Albrecht, J. Incl. Phenom. Macrocyclic Chem. 36 (2000) 127.
[2] Z. Dinev, J.N. Lambert, Aust. J. Chem. 54 (2001) 625.
[3] P.H. Dinolfo, J.T. Hupp, Chem. Mater. 13 (2001) 3113.
[4] M. Fujita, K. Umemoto, M. Yoshizawa, N. Fujita, T. Kusukawa,
K. Biradha, Chem. Commun. (2001) 509.
[26] R.J. Cross, A.J. McLennan, J. Chem. Soc., Dalton Trans. (1983)
359.
[27] O. Krizanovic, F.J. Pesch, B. Lippert, Inorg. Chim. Acta 165
(1989) 145.
[28] F.J. Pesch, M. Wienken, H. Preut, A. Tenten, B. Lippert, Inorg.
Chim. Acta 197 (1992) 243.
[5] B.J. Holliday, C.A. Mirkin, Angew. Chem. Int. Ed. 40 (2001)
2022.
[29] R.J. Puddephatt, P.J. Thompson, J. Chem. Soc., Dalton Trans.
(1977) 1219.
[6] S. Leininger, B. Olenyuk, P.J. Stang, Chem. Rev. 100 (2000) 853.
[7] F.M. Raymo, J.F. Stoddart, Curr. Opin. Colloid Interf. Sci. 3
(1998) 150.
[30] R. Ugo, F. Cariati, G. La Monica, Inorg. Synth. 28 (1990) 123.
[31] T. Yoshida, T. Matsuda, S. Otsuka, Inorg. Synth. 28 (1990) 122.
[32] R. Campbell, C.J. Peterson, J. Org. Chem. 28 (1963) 2294.
[8] P.J. Stang, Chem. Eur. J. 4 (1998) 19.
[9] G.F. Swiegers, T.J. Malefetse, Chem. Rev. 100 (2000) 3483.