The structures and decomposition products of palladium(II) and platinum(II) terpyridine phenoxide complexes

Article abstract of DOI:10.1016/S1387-7003(03)00052-2

A series of complexes of formula [Pd(OR)(terpy)]BF₄ and [Pt(OR)(terpy)]BF₄ (ROH = a substituted phenol; terpy = 2,2′:6′,2″-terpyridine) have been prepared by reaction of [M(OH) (terpy)]BF₄ (M = Pd, Pt) with ROH. One Pd(II) and one Pt(II) complex in this series have been structurally characterised. These compounds are very acid sensitive; decomposition products resulting from recrystallisation of two of these compounds from MeNO₂ or MeCN have been crystallographically characterised.

Full text of DOI:10.1016/S1387-7003(03)00052-2

Inorganic Chemistry Communications 6 (2003) 598–603
www.elsevier.com/locate/inoche
The structures and decomposition products of palladium(II)
and platinum(II) terpyridine phenoxide complexes
*
Xiaoming Liu, Sylvie L. Renard, Colin A. Kilner, Malcolm A. Halcrow
Department of Chemistry, University of Leeds, Woodhouse Lane, Leeds LS2 9JT, UK
Received 4 December 2002; accepted 27 January 2003
Abstract
Aseries of complexes of formula ½PdðORÞðterpyފBF4 and ½PtðORÞðterpyފBF4 (ROH ¼ a substituted phenol; terpy ¼ 2,20:60,200-
terpyridine) have been prepared by reaction of ½MðOHÞðterpyފBF4 (M ¼ Pd, Pt) with ROH. One Pd(II) and one Pt(II) complex in
this series have been structurally characterised. These compounds are very acid sensitive; decomposition products resulting from
recrystallisation of two of these compounds from MeNO2 or MeCN have been crystallographically characterised.
Ó 2003 Elsevier Science B.V. All rights reserved.
Keywords: Palladium complexes; Platinum complexes; Phenoxide complexes; Crystal structure
1. Introduction
We have recently prepared a series of hydroxy
[3.3]cyclophanes, whose conformations can be control-
lably switched between a fluxional chair–boat form, in
which the two annelated benzo groups lie far apart; and, a
rigid twin-chair form, in which the benzo rings are now
stacked upon each other [29]. While these compounds
were originally intended to model a biological phenoxyl
radical cofactor, we have been interested to explore al-
Alarge number of different Pd(II) and Pt(II) com-
þ
plexes have been reported of formula ½MXðterpyފ or
3þ
½fMðterpyÞg2ðl-Yފ
(M ¼ Pd, Pt), where XÀ is a
monodentate ligand such as ClÀ [1–5], OHÀ [6,7],
OCHÀ3 [7], NCSÀ [7], SRÀ [8], CH2RÀ [5,9–11], C3H3R2À
[12], C ꢀ CRÀ [13], NHRÀ [14] or N ꢀ CNRÀ [15] (not
a comprehensive list); or, Y ¼ SRÀ [16,17], cis-½PdðSC2
H4NH2Þ2Š [18], Et2NCSÀ2 [19], guanadinide [20,21],
ternative aspects of their cþhemistry. Since complexes of
þ
formula ½PdðORÞðterpyފ
and ½PdðORÞ ðterpyފ
2þ
amidinate [22] or pyrazolide [23]. Several ½MZðterpyފ
(R ¼ aryl) have not yet been reported, we have synthesised
the new complexes ½PdLðterpyފBF4 (HL ¼ HL1, 1;
HL ¼ HL2, 2; HL ¼ HL3, 3) and ½PtLðterpyފ BF4
(HL ¼ÀHL1, 4; HL ¼ HL2, 5; HL ¼ HL3, 6). Complexes
of ½L1Š were also studied, as a control.
derivatives with neutral N- or O-donor Z coligands are
also known [4,6,16,24]. The optical and emission spectra
of many of the Pt complexes have been widely studied,
since these are very dependent on theþmode of inter-
molecular association of the ½Ptðterpyފ centres in the
solid state [25]; or, in the binuclear species, on the
þ
þ
proximity of the two ½Ptðterpyފ moieties to each other
[19,21,26]. Several ½PtXðterpyފ derivatives have also
been shown to bind strongly to DNA[27] and to pro-
teins [28].
* Corresponding author. Tel. +44-113-343-6506; fax: +44-113-343-
6565.
E-mail address: m.a.halcrow@chem.leeds.ac.uk (M.A. Halcrow).
1387-7003/03/$ - see front matter Ó 2003 Elsevier Science B.V. All rights reserved.
doi:10.1016/S1387-7003(03)00052-2

X. Liu et al. / Inorganic Chemistry Communications 6 (2003) 598–603
599
2. Experimental
For ½PtðL3ÞðterpyފBF4 (6): Found: C, 51.0; H, 4.0; N,
4.7%. Calcd. for C36H32BF4N3O3Pt: C, 51.7; H, 3.9; N,
5.0%. FAB mass þspectrum: m/z 749 ½195PtðL3Þðterpyފþ,
2.1. Syntheses of the complexes
þ
428 ½195Ptðterpyފ , 322 ½L3Š with correct isotopic dis-
The syntheses of all of the complexes followed the
same basic procedure, as described here for 1. To a
suspension of ½PdðterpyÞðOHފBF4 (0.050 g, 1:12 Â
10À4 mol) [6] in freshly distilled CH2Cl2 (10 cm3) was
added HL1 (0.016 g, 1:34 Â 10À4 mol). The mixture
was refluxed for 1 h, until almost all of the solid had
dissolved, affording a deep red solution. Insoluble
materials were removed, and the filtrate concentrated
to ca. 2 cm3. Diffusion of Et2O vapour into this so-
lution afforded a red polycrystalline product. Similar
reactions using HL2 [29] or HL3 [29] afforded 2 and 3,
respectively. Yields of 1–3 ranged from 80% to 90%.
An identical method starting from ½PtðterpyÞðOHފBF4
[7] was used for the Pt complexes, except that the
mixture was kept refluxing for 7 days. Yields of 4–6
were lower at 50–75%.
For ½PdðL1ÞðterpyފBF4 (1): Found: C, 50.4; H, 4.1; N,
7.4%. Calcd. for C23H20BF4N3OPd: C, 50.2; H, 4.2; N,
7.6%. FAB mass sþpectrum: m/z 460 ½106PdðL1Þðterpyފþ,
339 ½106Pdðterpyފ with correct isotopic distributions.
UV/Vis (CH2Cl2): kmax, nm ðemax, M1 cmÀ1) 244 (56,300),
277 (33,600), 306 (21,900), 328 (13,900), 344 (14,600), 360
(11,700), 436 (sh).
tributions. UV/Vis (CH2Cl2): kmax, nm ðemax, MÀ1 cmÀ1
)
234 (32,100), 259 (32,300), 282 (30,600), 318 (14,600), 332
(14,200), 370 (sh), 385 (sh), 567 (740).
2.2. Single crystal X-ray structure determinations
Thin red plates of ½PdðL1ÞðterpyފBF4 (1) and
½PtðL1ÞðterpyފBF4 (4) were grown from CH2Cl2=Et2O/
hexanes. Recrystallisation of 5 from MeNO2=Et2O led to
its clean conversion to yellow crystals of ½PtðCH2NO2Þ
ðterpyފBF4. Recrystallisation of 1 from MeCN/Et2O
afforded a small number of yellow crystals of ½fPd
ðterpyÞg2ðl-NHCgCH3ފ½BF4Š3 Á 2CH3CN (8 Á 2CH3CN),
contaminated by an excess of a yellow powder. Experi-
mental details from the structure determinations are given
in Table 1. All structures were solved by direct methods
(SHELXS 86 [33]) and refined by full matrix least squares
on F 2 (SHELXL 97 [34]). The X-ray datasets from 1 and,
particularly, 4 and 7 suffer from absorption problems
leading to several intense residual Fourier peaks around
the heavy metal atoms. These could be a reflection of their
heavily anisotropic morphologies; 1 and 4 crystallise as
thin plates, while 7 has a needle morphology.
For ½PdðL2ÞðterpyފBF4 (2): Found: C, 57.1; H, 4.2; N,
5.6%. Calcd. for C34H28BF4N3O2Pd: C, 58.0; H, 4.0; N,
5.9%. FAB mass þspectrum: þm/z 616 ½106PdðterpyÞL2Šþ,
339 ½106Pdðterpyފ , 278 ½L2Š with correct isotopic dis-
No disorder was detected during refinement of any
of these structures, and no restraints were applied. All
non-H atoms were refined anisotropically. For 1, 4 and
7 all H atoms were placed in calculated positions and
refined using a riding model. However, for 8 all H
atoms in the complex trication were located in the
difference map and allowed to refine freely, while the H
atoms on the CH3CN molecules in this structure were
placed in calculated positions and refined using a riding
model.
tributions. UV/Vis (CH2Cl2): kmax, nm (emax, MÀ1 cmÀ1
)
245 (43,400), 276 (29,000), 306 (18,700), 329 (12,600), 344
(13,000), 361 (11,000), 429 (sh).
For ½PdðL3ÞðterpyފBF4 (3): Found: C, 57.6; H, 4.5; N,
5.4%. Calcd. for C36H32BF4N3O3Pd: C, 57.8; H, 4.3; N,
5.6%. FAB mass sþpectrum: m/z 660 ½106PdðL3Þðterpyފþ,
339 ½106Pdðterpyފ with correct isotopic distributions.
UV/Vis (CH2Cl2): kmax, nm ðemax, MÀ1 cmÀ1) 244
(43,300), 274 (28,600), 306 (17,700), 328 (11,100), 344
(11,300), 360 (8,900), 447 (sh).
2.3. Other measurements
UV/Visible spectra were obtained with a Perkin–
Elmer Lambda 12 spectrophotometer, operating be-
tween 100 and 200 nm, in 1 cm quartz cells. Positive ion
fast atom bombardment mass spectra were performed
on a VG Autospec MS890 spectrometer, employing a 3-
NOBAmatrix. CHN microanalyses were performed by
the University of Leeds Department of Chemistry mi-
croanalytical service.
For ½PtðL1ÞðterpyފBF4 (4): Found: C, 43.2; H,
3.4; N, 6.5%. Calcd. for C23H20BF4N3OPt: C, 43.4;
H, 3.2; N, 6.6þ%. FAB mass specþtrum: m/z 550
½
195PtðL1Þðterpyފ , 428 ½195Ptðterpyފ with correct
isotopic distributions. UV/Vis (CH2Cl2): kmax, nm
ðemax, MÀ1 cmÀ1) 243 (29,200), 258 (29,100), 282
(28,200), 307 (12,400), 320 (13,300), 331 (13,300), 348
(8,400), 388 (sh), 540 (850).
For ½PtðL2ÞðterpyފBF4 (5): Found: C, 50.8; H, 3.7; N,
5.0%. Calcd. for C34H28BF4N3O2Pt: C, 51.4; H, 3.6; N,
5.3%. FAB mass spectrum: m/z 705 ½195PtðL2Þðterpyފþ,
3. Results and discussion
þ
428 ½195Ptðterpyފ with correct isotope distributions.
Attempted syntheses of 1–6 by reacting ½MClðterpyފ
BF4 (M ¼ Pd, Pt) with the appropriate phenol under
neutral or basic conditions did not yield clean products.
However, reaction of ½MðOHÞðterpyފ BF4 (M ¼ Pd, Pt)
UV/Vis (CH2Cl2): kmax, nm ðemax, MÀ1 cmÀ1) 253
(38,200), 282 (34,000), 305 (15,000), 318 (15,700), 331
(15,500), 348 (11,600), 392 (sh), 515 (1,400).

Table 1
Experimental details for the single crystal structure determinations in this study
½PdðL1ÞðterpyފBF4 (1)
½PtðL1ÞðterpyފBF4 (4)
½PtðCH2NO2Þ ðterpyފBF4 (7)
½fPdðterpyÞg ðl-NHCfOgCH3ފ½BF4Š Á
2CH3CNð8 Á22CH3CNÞ
C36H32B3F12N9OPd2
3
Formula
Mr
Crystal system
C23H20BF4N3Opd
547.63
Monoclinic
C23H20BF4N3OPt
636.32
Monoclinic
C16H13BF4N4O2Pt
575.20
Monoclinic
1079.94
Triclinic
ꢀ
Space group
ꢁ
P21=n
P21=n
P21=n
P1
a ðAÞ
10.6077(1)
13.2571(1)
30.4366(4)
–
10.6014(1)
13.2489(1)
30.4958(4)
–
8.2868(1)
10.6173(2)
19.0328(3)
–
12.3743(1)
13.0949(1)
14.4584(2)
64.3486(5)
72.5261(5)
83.5104(4)
2013.95(4)
2
ꢁ
b ðAÞ
ꢁ
c ðAÞ
a ð°Þ
b ð°Þ
c ð°Þ
95.1621(5)
–
95.0067(5)
–
92.4214(7)
–
ꢁ3
V ðA Þ
4262.86(8)
8
1.707
4267.00(8)
8
1.981
1673.08(5)
4
2.284
Z
Dc ðmg mÀ3
Þ
1.781
0.993
l ðMo-Ka; mmÀ1
TðKÞ
Þ
0.927
150(2)
6.633
150(2)
8.451
150(2)
150(2)
37133
Measured reflections
Unique reflections
Rint
66080
9758
38715
9688
28163
3847
9044
0.060
0.090
599
0.139
599
0.102
253
No. of parameters
a
672
0.033, 0.088
1.037
RðF Þ , wRðF 2Þ
0.051, 0.140
1.024
0.074, 0.221
1.026
0.035, 0.093
1.066
b
GOF
P
a R ¼ ½jF0j À jFcjŠ= jF0j.
ꢁ
ꢂ1=2
P
P
b wR ¼
wF04
.

X. Liu et al. / Inorganic Chemistry Communications 6 (2003) 598–603
601
with HL1–HL3 in acid-free CH2Cl2 did afford 1–6 in
moderate-to-good yields. All these complexes are air-
and moisture-stable red solids, which are air-stable in
solution but very sensitive to the presence of acid. Thus,
1–6 decompose over periods of hours when dissolved in
weakly acidic solvents like MeNO2, MeCN and acetone
(see below), but can be safely handled in air in acid-free
CH2Cl2, CHCl3 or toluene. The UV/Vis spectra of 1–6
in CH2Cl2 are complex, showing a highest wavelength
band at kmax ¼ 429–447 nm (M ¼ Pd) and 515–567 nm
(M ¼ Pt). The wavelength of this peak is dependent on
the pheÀnoxide lÀigand prÀesent, following the trend in kmax
of ½L3Š > ½L1Š > ½L2Š for both series of complexes.
Fig. 1. View of the two crystallographically independent ½PdðL1Þ
À
þ
This transition is therefore assigned as a ½ORŠ ! M
ðterpyފ cations in the crystal structure of 1, showing the atom num-
bering scheme employed. Thermal ellipsoids are drawn at the 50%
probability level. For clarity, all C-bound H atoms have been omitted.
(M ¼ Pd, Pt) charge transfer.
Of the above compounds, only 1 and 4 form crystals
that are suitable for X-ray structure determination.
These crystals are isomorphous, with two crystallo-
graphically independent molecules in the asymmetric
unit that have almost identical molecular structures
(Table 2, Fig. 1). The complexes adopt the expected
approximately square-planar geometry. The M–O
(M ¼ Pd, Pt) bond lengths are typical for phenoxide li-
gands to these metal ions trans to a N-donor [30], al-
though the Pt–O distances in 4 are slightly longer than
the Pd–O bonds in 1 (Table 1). All the other metric
parameters are very similar in the two structures. The
dihedral angles between the least squares planes of the
þ
The ½PtðL1Þðterpyފ cations in 4 are visually indistinguishable from
those of 1, and employ the same atom numbering scheme with Pd(1) and
Pd(29) replaced by Pt(1) and Pt(29).
from 0° or 90° suggests that there is no significant p-
bonding between the metal ions and phenoxide ligands.
The two molecules in 1 and 4 are almost coparallel in
the crystal, and pack in 1-D stacks parallel to the crys-
tallographic a direction (in the setting P21=n, Fig. 2); the
dihedral angles between the [MN3O] (M ¼ Pd, Pt) least
squares planes on adjacent molecules in these stacks is
5.88(16)° for 1, and 5.4(4)° for 4. Despite the formal
aggregation of these columns into crystallographically
unique dimers, the two sets of unique intermolecular
distances within each stack are almost equal, as shown
À
½L1Š and terpy ligands bound to M(1) and M(29) are,
respectively, 71.30(9)° and 73.49(9)° in 1, and 70.43(17)°
and 71.82(17)° in 4. The high deviation of these angles
Table 2
1
ꢁ
Selected bond lengths (A) and angles (°) for ½PdðL ÞðterpyފBF4 (1)
and ½PtðL1ÞðterpyފBF4 (4)
1 [M ¼ Pd]
4 [M ¼ Pt]
M(1)–N(2)
M(1)–N(9)
1.944(4)
2.007(4)
2.041(4)
1.979(3)
1.930(3)
2.020(4)
2.033(3)
1.988(3)
1.935(7)
2.010(7)
2.016(7)
2.009(6)
1.933(7)
1.999(8)
2.017(7)
2.010(5)
M(1)–N(15)
M(1)–O(20)
M(29)–N(30)
M(29)–N(37)
M(29)–N(43)
M(29)–O(48)
N(2)–M(1)–N(9)
81.17(16)
80.80(15)
175.62(13)
161.95(16)
96.09(15)
101.97(14)
80.87(15)
81.11(15)
175.60(13)
161.95(15)
101.49(14)
96.56(14)
81.0(4)
82.2(3)
175.3(3)
163.2(3)
95.9(3)
100.9(3)
80.8(3)
81.3(3)
175.9(3)
162.0(3)
101.3(3)
96.6(3)
N(2)–M(1)– N(15)
N(2)–M(1)–O(20)
N(9)–M(1)–N(15)
N(9)–M(1)–O(20)
N(15)–M(1)–O(20)
N(30)–M(29)–N(37)
N(30)–M(29)– N(43)
N(30)–M(29)–O(48)
N(37)–M(29)–N(43)
N(37)–M(29)–O(48)
N(43)–M(29)–O(48)
Fig. 2. View of the association of the complex cations in 1 (M ¼ Pd)
ꢁ
into 1-D stacks. The intermolecular distances quoted (A) are: the
shortest C Á Á Á C distance between each adjacent terpy ligand; the
shortest O Á Á Á C intermolecular contact made by the phenoxide O-do-
nors; and, the metal Á Á Á metal distance. The figures in square brackets
are the corresponding parameters for 4 (M ¼ Pt).

602
X. Liu et al. / Inorganic Chemistry Communications 6 (2003) 598–603
ꢁ
in Fig. 2. The distances of 3.3–3.4 Abetween each terpy
ligand are consistent with an attractive p–p interaction
between each molecule in the columns. However, adja-
ꢁ
cent molecules in the stacks are offset by 4.10–4.12 A , so
ꢁ
that the M Á Á Á M distances are 5.3 A(Fig. 2). This rules
out significant overlap between the dz2 orbitals on ad-
jacent Pd or Pt centres, which is a feature of many red
crystals of Pt(II)/imine complexes [31].
As described earlier, 1–6 decompose upon dissolution
in weakly acidic organic solvents, as evidenced by a colour
change from red to yellow. We were able to crystallise
decomposition products from two of the resultant solu-
tions. First, dissolution of 5 in MeNO2 resulted in its clean
conversion to yellow ½PtðCH2NO2ÞðterpyފBF4 (7). The
molecular structure of 7 is identical to that of the BPh4À
salt of the same complex cation [11]. The Pt(II) centres in 7
associate into coparallel dimers related by the centre of
symmetry 1 À x; Ày; 1 À z; these dimers aggregate further
into 1-D stacks via a second inversion centre Àx; Ày;1 À z.
Fig. 3. View of the hydrogen-bonded ½fPdðterpyÞg2ðl-NHC
0
3þ
trication and BFÀ4 anion in the crystal structure of
ꢁ
In 7, the intradimer Ptð1Þ Á Á Á Ptð1 Þ ¼ 5:2473ð3Þ Awhile
fOgCH3ފ
ꢁ
8 Á 2CH3CN, showing the atom numbering scheme employed. Details
the intermolecular separation is 3.36 A. The corre-
ꢁ
as for Fig. 1. Selected bond lengths (A) and angles (°): Pd(1)–N(2)
sponding interdimer distances are Ptð1Þ Á Á Á Ptð100Þ ¼
1.9331(17), Pd(1)–N(9) 2.0310(18), Pd(1)–N(15) 2.0323(17), Pd(1)–
O(41) 2.0215(14), Pd(20)–N(21) 1.9433(17), Pd(20)–N(28) 2.0288(18),
Pd(20)–N(34) 2.0315(18), Pd(20)–O(42) 2.0174(18), N(2)–Pd(1)–N(9)
81.14(7), N(2)–Pd(1)– N(15) 81.10(7), N(2)–Pd(1)–O(41) 177.30(6),
N(9)–Pd(1)–N(15) 162.23(7), N(9)–Pd(1)–O(41) 96.94(7), N(15)–
Pd(1)–O(41) 100.79(7), N(21)–Pd(20)–N(28) 80.88(7), N(21)–Pd
(20)–N(34) 80.78(7), N(21)–Pd(20)–N(42) 173.97(7), N(28)–Pd(20)–
N(34) 160.86(8), N(28)–Pd(20)–N(42) 100.42(7), N(34)–Pd(20)–N(42)
98.39(7).
ꢁ
5:1986ð3Þ and 3.53 A. Hence, adjacent molecules within
the stacks are offset with respect to each other, by 4.0 and
ꢁ
3.8 A, respectively. This contrasts with the 1-D stacking
motif in ½PtðCH2NO2ÞðterpyފBPh4, where individual
molecules are still related by inversion centres but are not
now offset, so that the Pt Á Á Á Pt separation within the chain
ꢁ
is 3.4039(4) A. This accounts for the different colours of 7
(yellow) and the BPhÀ4 salt (red) [11].
Secondly, recrystallisation of 1 from MeCN/Et2O
yielded a large amount of an unknown yellow powder,
together with a small number of yellow crystals that were
identified by X-ray crystallography as ½fPdðterpyÞg2
torsion angle Nð2Þ–Pdð1ÞÁÁÁ Pdð20Þ–Nð21Þ being 14.47(7)°.
Two complex molecules are associated into coparall0el p–p
ꢁ
dimers separated by 3.19 A, with a Pdð1Þ Á Á Á Pdð1 Þ dis-
ꢁ
tance of 3.2328(3) A(related by 1 À x; 1 À y; 1 À z). Sim-
ðl-NHCfOgCH3ފ½BF4Š (8). The acetamidate bridging
3
ilar aggregation at the other face of the molecule is
blocked by a hydrogen bond between the acetamido N–H
group and a BFÀ4 anion (Fig. 3). Compound 8 is the first
crystallographically characterised Pd(II) analogue of the
ligand in 8 must arise from hydrolysis of MeCN with
adventitious water, promoted either by the presence of
phenoxide base, or by coordination to Pd after initial
À
hydrolysis of the Pd–½L1Š bond. The Pd(II)-effected
3þ
well-known series of ½fPtðterpyÞg2ðl-Zފ complexes,
hydrolysis of nitriles is unusual, but does have litera-
ture precedent [32]. Unfortunately, our attempts to
obtain 8 in pure form by reaction of ½PdðOHÞðterpyފ
BF4 [6] with MeCN at room temperature or under
reflux yielded impure product contaminated by an
excess of unreacted starting material, which we were
unable to remove by recrystallisation. Hence, we were
unable to characterise 8 beyond determining its crystal
structure.
where ZÀ is
a 1,3-bridging ligand [17–22]. The
Pdð1Þ Á Á Á Pdð20Þ distance in 8 is at the low end of the range
previously observed in the Pt compounds [19]. Despite
this, its yellow colouration suggests that there is no sig-
nificant 4dz2 –4dz2 overlap between the Pd centres in 8.
In summary, we have prepared the first complexes of
þ
þ
type ½PdðORÞðterpyފ and ½PtðORÞðterpyފ (R ¼ aryl).
These represent a new extension to the well-established
Pd(II) and Pt(II) terpyridine chemistry, whose emissive
and electrochemical properties are likely to be of inter-
est. These complexes are sensitive to weak organic acids,
and we have characterised two unusual decomposition
products. One of these is the first Pd(II) analogue of the
well-known series of diplatinum face-to-face complexes,
The complex cation of 8 consists of two square-planar
Pd(II) centres, linked by a 1,3-acetamidato bridge (Table
2, Fig. 3). The dihedral angle between the two [PdN3Y]
(Y ¼ N or O) planes in the molecule is 17.94(8)°, which
reflects the small bite distance of the acetamidate group,
ꢁ
Oð41Þ Á Á Á Nð42Þ ¼ 2:292ð2Þ A, compared to the Pdð1Þ Á Á Á
2þ
ꢁ
containing two ½Mðterpyފ (M ¼ Pd, Pt) centres linked
Pdð20Þ distance of 3.0570(2) A. The two [Pd(terpy)Y]
by a 1,3-bridging ligand.
moieties are also slipped with respect to each other, the

X. Liu et al. / Inorganic Chemistry Communications 6 (2003) 598–603
603
[12] (a) R.E. Ruelke, D. Kliphuis, C.J. Elsevier, J. Franje, K. Goubitz,
P.W.N.M. van Leeuwen, K. Vrieze, J. Chem. Soc. Chem.
Commun. (1994) 1817;
Supplementarydata
Full crystallographic data for the structure analysis in
this study are available on request from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cam-
bridge CB2 1EZ, UK (fax: +44-1223-336033; e-mail:
deposit@ccdc.cam.ac.uk), quoting deposition numbers
198482 (1), 198483 (4), 198484 (7) and 198485
(8 Á 2CH3CN).
(b) S. Ramdeehul, L. Barloy, J.A. Osbourn, A. de Cian, J.
Fischer, Organometallics 15 (1996) 5442;
(c) L. Barloy, S. Ramdeehul, J.A. Osbourn, C. Carlotti, F.
Taulelle, A. de Cian, J. Fischer, Eur. J. Inorg. Chem. (2000) 2523.
[13] (a) V.W.-W. Yam, R.P.-L. Tang, K.M.-C. Wong, K.-K. Cheung,
Organometallics 20 (2001) 4476;
(b) V.W.-W. Yam, K.M.-C. Wong, N. Zhu, J. Am. Chem. Soc.
124 (2002) 6506.
[14] L. Barloy, M.R. Gauvin, J.A. Osbourn, C. Sizun, R. Graaf, N.
Kyritsakas, Eur. J. Inorg. Chem. (2001) 1699.
[15] W. Zhang, C. Bensimon, R.J. Crutchley, Inorg. Chem. 32 (1993)
5808.
Acknowledgements
[16] G. Annabile, P. Bergamini, V. Bertolasi, M. Cattabriga, A.
Lazzaro, A. Marchi, G. Vertuani, J. Chem. Soc. Dalton Trans.
(1999) 3877.
The authors gratefully acknowledge funding by The
Royal Society (M.A.H.), the EPSRC (X.L., S.L.R.) and
the University of Leeds.
[17] G. Lowe, S.A. Ross, M. Probert, A. Cowley, Chem. Commun.
(2001) 1288.
[18] (a) J.C. Dewan, S.J. Lippard, W.R. Bauer, J. Am. Chem. Soc. 102
(1980) 858;
(b) Y. Yamada, K. Fujisawa, K. Okamoto, Bull. Chem. Soc. Jpn.
73 (2000) 2297.
References
[19] M. Akiba, K. Umakoshi, Y. Sasaki, Chem. Lett. (1995) 607.
[20] (a) E.M.A. Ratilla, B.K. Scott, M.S. Moxness, N.M. Kostic,
Inorg. Chem. 29 (1990) 918;
[1] G.M. Intille, C.E. Pfluger, W.A. Baker Jr., J. Cryst. Mol. Struct. 3
(1973) 47.
(b) M. Kato, A. Toshikawa, K. Shinobu, Acta Crystallogr. Sect.
E 58 (2002) m248.
[2] Y. Wong, S.J. Lippard, J. Chem. Soc., Chem. Commun. (1977)
824.
[21] H.-K. Yip, C.-M. Che, Z.-Y. Zhou, T.C.W. Mak, J. Chem. Soc.
Chem. Commun. (1992) 1369.
[3] (a) H.-K. Yip, L.-K. Cheng, K.-K. Cheung, C.-M. Che, J. Chem.
Soc. Dalton Trans. (1993) 2933;
[22] J.A. Bailey, V.M. Miskowski, H.B. Gray, Acta Crystallogr. Sect.
C 49 (1993) 733.
(b) J.A. Bailey, M.G. Hill, R.E. Marsh, V.M. Miskowski, W.P.
Schaefer, H.B. Gray, Inorg. Chem. 34 (1995) 4591;
€
[23] J.A. Bailey, H.B. Gray, Acta Crystallogr. Sect. C 48 (1992) 1420.
[24] (a) A.W. Roszak, O. Clement, E. Buncel, Acta Crystallogr. Sect.
C 52 (1996) 1645;
(c) R. Buchner, C.T. Cunningham, J.S. Field, R.J. Haines, D.R.
McMillin, G.C. Summerton, J. Chem. Soc., Dalton Trans. (1999)
711;
(b) A. Chernega, A.D. Drosz, K. Prout, T. Vilaivan, G.W.
Weaver, G. Lowe, J. Chem. Res. (S) (1996) 402;
(c) S. Cosar, M.B.L. Janik, M. Klock, E. Freisinger, E. Farkas, B.
Lippert, J. Chem. Soc. Dalton Trans. (1999) 2329.
[25] D.R. McMillin, J.J. Moore, Coord. Chem. Rev. 229 (2002) 113.
[26] J.A. Bailey, V.M. Miskowski, H.B. Gray, Inorg. Chem. 32 (1993)
369.
(d) J.S. Field, R.J. Haynes, D.R. McMillin, C.G. Summerton, J.
Chem. Soc., Dalton Trans. (2002) 1369.
€
[4] R. Buchner, J.S. Field, R.J. Haines, C.T. Cunningham, D.R.
McMillin, Inorg. Chem. 36 (1997) 3952.
[5] S.-W. Lai, M.C.W. Chan, K.-K. Cheung, C.-M. Che, Inorg.
Chem. 38 (1999) 4262.
[6] P. Castan, F. Dahan, S. Wimmer, F.L. Wimmer, J. Chem. Soc.,
Dalton Trans. (1990) 2679.
[27] (a) K.W. Jennette, S.J. Lippard, G.A. Vassiliades, W.R. Bauer,
Proc. Natl. Acad. Sci. USA 71 (1974) 3839;
[7] T.K. Aldridge, E.M. Stacey, D.R. McMillin, Inorg. Chem. 33
(1994) 722.
(b) A.H.J. Wang, J.M. Nathans, G. van der Marel, J.H. van
Boom, A. Rich, Nature (London) 276 (1978) 471.
[28] E.M.A. Ratilla, N.M. Kostic, J. Am. Chem. Soc. 110 (1988) 4427.
[29] X. Liu, S.A. Barrett, C.A. Kilner, M. Thornton-Pett, M.A.
Halcrow, Tetrahedron 58 (2002) 603.
[8] (a) K.W. Jennette, J.T. Gill, J.A. Sadownick, S.J. Lippard, J. Am.
Chem. Soc. 98 (1976) 6159;
(b) B.-C. Tzeng, W.-F. Fu, C.-M. Che, H.-Y. Chao, K.K.
Cheung, S.-M. Peng, J. Chem. Soc. Dalton Trans. (1999)
1017;
[30] G.M. Kapteijn, M.D. Meijer, D.M. Grove, N. Veldman, A.L.
Spek, G. van Koten, Inorg. Chim. Acta 264 (1997) 211, and
references therein.
(c)
V.W.-W. Yam, R.P.-L. Tang, K.M.-C. Wong, C.-C.
Ko, K.K. Cheung, Inorg. Chem. 40 (2001) 571;
(d) S.A. Ross, G. Lowe, D.J. Watkin, Acta Crystallogr.,
Sect. C 57 (2001) 275.
[31] V.H. Houldin, V.M. Miskowski, Coord. Chem. Rev. 111 (1991)
145.
€
[32] (a) S. Paraskewas, Synthesis (1974) 574;
(b) N.V. Kaminskaya, N.M. Kostic, J. Chem. Soc. Dalton Trans.
(1996) 3677;
[9] (a) R.E. Rulke, I.M. Han, C.J. Elsevier, K. Vrieze, P.W.M.N. van
Leeuwen, C.F. Roobeek, M.C. Zoutberg, Y.F. Wang, C.H. Stam,
Inorg. Chim. Acta 169 (1990) 5;
€
(c) N.V. Kaminskaya, I.A. Guzei, N.M. Kostic, J. Chem. Soc.
Dalton Trans. (1998) 3879;
(b) R.E. Rulke, V.E. Kaasjager, D. Kliphuis, J. Elsevier,
P.W.M.N. van Leeuwen, K. Vrieze, K. Goubitz, Organometallics
15 (1996) 668.
ꢂ
(d) J. Ruiz, N. Cutillas, V. Rodriguez, J. Sampedro, G. Lopez,
P.A. Chaloner, P.B. Hitchcock, J. Chem. Soc. Dalton Trans.
(1999) 2939.
[10] (a) G. Arena, L.M. Scolaro, R.F. Pasternack, R. Romeo, Inorg.
Chem. 34 (1995) 2994;
[33] G.M. Sheldrick, Acta Crystallogr., Sect. A 46 (1990) 467.
[34] G.M. Sheldrick, SHELXL-97, Program for the refinement of
(b) R. Romeo, L.M. Scolaro, M.R. Plutino, A. Albinati, J.
Organomet. Chem. 593 (2000) 403.
[11] M. Akiba, Y. Saski, Inorg. Chem. Commun. 1 (1998) 61.
€
crystal structures, University of Gottingen, 1997.