Bimetallic complexes of porphyrinphenanthroline: Preparation and catalytic activities

Article abstract of DOI:10.1016/j.ica.2010.07.008

Condensation of tetraphenylporphyrin-2,3-dione with 1,10-phenanthroline-5, 6-diamine provided porphyrinphenanthroline (2) as the desired ligand. Metallation of the porphyrinic site of 2 with CoCl₂, NiCl ₂, ZnCl₂ and CuCl

Full text of DOI:10.1016/j.ica.2010.07.008

Inorganica Chimica Acta 363 (2010) 3523–3529
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Inorganica Chimica Acta
journal homepage: www.elsevier.com/locate/ica
Bimetallic complexes of porphyrinphenanthroline: Preparation
and catalytic activities
*
Rong-Shin Lin, Meng-Ru Li, Yi-Hong Liu, Shei-Ming Peng, Shiuh-Tzung Liu
Department of Chemistry, National Taiwan University, Taipei, Taiwan 106, ROC
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 15 June 2010
Received in revised form 4 July 2010
Accepted 5 July 2010
Available online 1 August 2010
Condensation of tetraphenylporphyrin-2,3-dione with 1,10-phenanthroline-5,6-diamine provided por-
phyrinphenanthroline (2) as the desired ligand. Metallation of the porphyrinic site of 2 with CoCl2, NiCl2,
ZnCl2 and CuCl2 afforded the corresponding metal complexes [Co(2)] (8a), [Ni(2)] (8b), [Zn(2)] (8c) and
[Cu(2)] (8d), respectively. Subsequent reactions of these metalloporphyrins with [(COD)PdCl2] yielded
the corresponding bimetallic complexes [Co/Pd (9a), Ni/Pd (9b), Zn/Pd (9c) and Cu/Pd (9d)] in high yields.
The bimetallic complex 9e (Mg/Pd) was prepared directly by complexation of 2 with MgBr2 and
[(COD)PdCl2]. All complexes were characterized by both spectroscopic and elemental analyses. In addi-
tion, crystal structure of 9c was determined to confirm its formulation. The use of these bimetallic com-
plexes as pre-catalysts for Mizoroki–Heck coupling reaction has been examined.
Keywords:
Porphyrin
Bimetallic complex
Palladium
Heck reaction
Phenanthroline
Ó 2010 Elsevier B.V. All rights reserved.
1. Introduction
Ar
Ar
Ar
Ar
R
R
N
H
The highly
p-conjugated chromophores are an important class
N
N
N
N
of compounds in material science due to the small HOMO–LUMO
gaps of these molecules [1,2]. In this context, the use of porphy-
rin as a core unit for construction of the extended-conjugation
has received much attention and several compounds of this type
have been synthesized, using accessible synthetic approaches
[3–18]. Compound 1 is a typical example, which is a porphyrin
system containing a 1,10-phenanthroline moiety fused at the
N
N
H
N
1
b-pyrrole positions, prepared by
a Schiff base condensation
2. Results and discussion
[18,19]. This phenanthroline-appended porphyrin is capable to
build various bimetallic complexes, providing the study of the
interaction between metal ions through the conjugation [19].
Other related systems have been reported [18–25], but none of
these studies concerns the use of the metal complexes for catal-
ysis. Here we would like to report the preparation of a series of
bimetallic complexes with meso-tetraphenylporphyrin–phenan-
throline 2 and their catalytic activities on the Mizoroki–Heck
coupling reaction.
2.1. Synthesis of meso-tetraphenylporphyrinphenanthroline
The synthetic approach leading to the desired compound 2
(Scheme 1) is similar to that employed for 1 by Crossley [18,19].
Porphyrin-a-dione 5 is prepared according to the reaction steps
shown in Scheme 1. Starting from copper(II) meso-tetraphenylpor-
phyrin 3, nitration at b-position was achieved by the reaction of 3
with Cu(NO)2 in acetic anhydride at room temperature for 20 h.
Subsequent de-metallation in dichloromethane under acidic condi-
tions afforded the expected b-nitro-tetraphenylporphyrin 4 in 76%
yield [26]. In the reduction of nitro functionality to give b-amino-
tetraphenylporphyrin (step iii, Scheme 1), we noticed that carrying
out the reaction of 4 with SnCl2 under microwave heating led to a
better yield as compared to an oil-bath heating. For the oxidation
of b-amino-tetraphenylporphyrin in the presence of air leading to
* Corresponding author. Tel.: +886 2 2366 0352; fax: +886 2 2363 6359.
E-mail address: stliu@ntu.edu.tw (S.-T. Liu).
0020-1693/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2010.07.008

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R.-S. Lin et al. / Inorganica Chimica Acta 363 (2010) 3523–3529
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
N
H
N
H
N
N Cu
N
O
O
iii
iv
NO2
i.
N
N
N
N
N
ii.
H
N
H
N
Ph
Ph
Ph
5
4
3
H2N
H2N
N
Ph
Ph
Ph
N
N
N
N
N
H
N
N
6
v
H
N
N
Ph
2
i. Cu(NO3)2, Ac2O; ii H2SO4, rt; iii SnCl2, HCl, microwave, 60oC, 30 min; iv. SiO2, hv, O2
v. CF3COOH, CH2Cl2, reflux.
Scheme 1.
5 (step iv, Scheme 1), neither oil-bath nor microwave heating pro-
moted the reaction smoothly. In all instances, only trace amount of
5 was obtained. However, when the reaction was performed under
irradiation of a 250 W light bulb in an opened-vessel, the oxidation
proceeded smoothly within 1 h, providing the dione 5 in 78% iso-
lated yield.
It is well documented that the condensation of o-phenylenedi-
amine with 1,2-diones provides the corresponding pyrazine [27].
However, condensation of 5 with 1,10-phenanthroline-5,6-dia-
mine 6 to yield the desired compound 2 appears to be a challenge.
When the condensation was performed under refluxing conditions,
instead of the expected porphyrin 2, the reaction provided an
unidentified product. Nevertheless, the desired product 2 could
be obtained by running the reaction in the presence of trifluoroace-
tic acid. Typically, a solution of equal molar amount of both reac-
tants in the presence of excess of CF3COOH was heated to reflux
overnight, yielding the porphyrin 2 in 46% isolated yield.
In the 1H NMR spectrum of 2, the NH protons of the pyrrole
moiety give a singlet at d – 2.62; three sets of resonances [d 9.24
(dd, J = 1.7, 4.3 Hz), 8.84 (dd, J = 1.7, 8 Hz) and 7.72 (dd, J = 4.3,
8 Hz) are in the appropriate area ratio and are assigned to the phe-
nanthroline moiety; the meso-protons give rise to two set of signals
at d 8.96 and 8.74, respectively. The spectral data of 2 is quite sim-
ilar to those of the related species [26], which supports the pro-
posed structure. Further confirmation comes from the X-ray
crystal structure of its metal complex (See Section 2.2).
2.2. Preparation of bimetallic palladium complexes
Scheme 2 presents the approach for the preparation a series of
bimetallic palladium complexes. Reaction of CoCl2 with an equal
molar amount of 2 resulted in the formation of a mixture of 8a,
10 and the free ligand. However, reaction of 2 with an excess of
CoCl2 provided the bimetallic complex 10 as the exclusive product
in 81% yield. De-complexation of the metal ion binding on the phe-
nanthroline moiety leading to 8a could be achieved by treatment
of 10 with ethylenediaminetetraacetic acid (EDTA) [16]. Typically,
a dichloromethane solution of 10 mixed with an aqueous buffer
Ph
Ph
Ph
Ph
N
M
N
N
M
N
N
N
N
N
N
N
N
N
Cl
Cl
1. M(II)X
2. 0,01M EDTA,
pH buffer = 4.7
2
2
Pd
N
N
N
N
[(COD)PdCl2]
Ph
Ph
Ph
Ph
8a M = Co
8b M = Ni
8c M = Zn
8d M = Cu
9a M = Co (Co/Pd)
9b M = Ni (Ni/Pd)
9c M = Zn (Zn/Pd)
9d M = Cu (Cu/Pd)
Ph
Ph
Ph
N
N
N
N
Cl
Cl
Co
N
N Co
N
N
Ph
10
Scheme 2.

R.-S. Lin et al. / Inorganica Chimica Acta 363 (2010) 3523–3529
3525
Table 2
solution of EDTA was stirred vigorously for 24 h and the organic
Partial 1H NMR data of phenanthroline moiety in complexes 8 and 9.
layer provided 8a as the single product upon concentration.
Finally, the same procedures were adopted to produce three
other metalloporphyrins 8b–d. Coordination of 8 with an equal
molar of [(COD)PdCl2] proceeded smoothly to afford the hetero-
bimetallic complexes 9a–d in high yields.
On the other hand, the preparation of Mg/Pd complex 9e is
quite straight forward. It is known that the coordination strength
of phenanthroline moiety toward the palladium is stronger than
that toward the magnesium ions. Thus, treatment of 2 with excess
of MgBr2 followed by the addition of [(COD)PdCl2] promptly affor-
ded the desired 9e (Mg/Pd) as shown in Eq. (1).
3
Ph
Ph
Ph
2
4
N
H
N
N
N
N
N
N
H
N
7
9
Ph
8
Entry
Compound
1H NMR data (in CDCl3, ppm)
H-(2,9)
H-(3,8)
H-(4,7)
1
2
3
4
5
6
7
8b
2
8b
8c
9b
9.24
9.22
9.07
9.68
9.41
9.43
9.13
9.28
7.72
7.90
7.69
7.97
8.08
8.07
7.62
8.15
8.84
8.79
8.81
8.89
8.86
8.91
8.27
9.02
Ph
Ph
N
N
N
N
N
Cl
Cl
1. MgBr2
2. Pd(COD)Cl2
2
N
Mg N
N
Pd
9c
ð1Þ
9e
Phena
Ph
Ph
(Phen)PdCl2
a
Phen: 1,10-phenanthroline.
Ref. [28].
9e (Mg/Pd)
The absorption spectra of 8a–e are dominated by the features of
b
the metalloporphyrin core, whose molar absorption coefficients
are similar to the free ligand. When 8a was treated with
[(COD)PdCl]2, a fast color change of the reaction mixture occurred,
which turned into red-brown, indicating the formation of new
complex. Both Soret and Q-band of 9a had shifted bathochromical-
ly by ꢀ20 nm with respect to 8a, and the molar absorption coeffi-
cient had increased (Table 1). For the nickel complex, the Soret
band and Q-band of 9b are quite similar to those of 8b even the
molar absorption coefficient. Other complexes behave similarly.
Electronic absorptions of all complexes are listed in Table 1.
In addition to the absorption spectroscopy, characterization of
complexes 9b(Ni/Pd), 9c(Zn/Pd) and 9e(Mg/Pd) complexes were
performed by NMR spectroscopy, but not 9a and 9d due to the
paramagnetic nature. Coordination of the palladium ion toward
the phenanthroline moiety of 2 is readily confirmed by its 1H
NMR spectrum, which shows the down-field shifts of H(2,9) and
H(4,7) on the phenanthroline moiety (Table 2). The coordination-
induced shift is larger for protons in the vicinity of the phenan-
throline-binding site, which is a typical observation for the related
palladium complex of 1,10-phenanthroline (Table 2) [28].
A single crystal X-ray diffraction study of 9c confirms the for-
mulation as a Zn/Pd bimetallic complex (Fig. 1). The crystal struc-
ture of 9c includes 2.5 molecule of dmso with one being
coordinated to metal center and others as disorder solvent packing.
As illustrated in Fig. 1, the Zn atom is seated as expected, in a
slightly distorted tetragonal pyramidal coordination with dmso
(dimethylsulfoxide) bound to the metal center, whereas the palla-
dium atom is in a disordered square planar geometry with the
coordination of phenanthroline and two chloride ligands. Selected
bond lengths and bond angles are summarized in Table 3 and all
are in the normal range as compared to those of the related species.
Analysis of the crystal packing interactions in the crystal of 9c
2.5(dmso) reveals another interesting consequence of the ex-
tended-conjugation porphyrin ligand. Because of the fixed planar-
ity of the conjugated system, 9c molecules arrange themselves into
two-dimensional layer. In the crystal, each complex interacts with
the other molecule via
intermolecular -stacking interactions involve the phenanthroline
ring of one molecule and the porphyrin core of the adjacent 9c
molecule in the anti parallel fashion. Such intermolecular -stack-
p-stacking interactions (Fig. 2). Two of the
p
p
ing interactions allow the palladium center lining up at the other
end. The distance between the palladium centers here is around
3.576 Å, showing a fairly weak metal–metal interaction.
2.3. Catalysis
With a series of bimetallic compounds 9a–e in hand, the use of
these complexes as pre-catalysts for the Mizoroki–Heck coupling
reaction between iodobenzene and butyl acrylate was investigated
(Eq. (2)) [29]. First, complex 9c(Zn/Pd) was employed as a preli-
minary test for the coupling reaction with which to survey the
optimized conditions. Results are summarized in Table 4. For car-
rying out the reactions in a organic solvent, ionic liquid or water,
complex 9c(Zn/Pd) proved to be catalytically inactive yielding neg-
ligible amounts of the desired product except in DMF. Both organic
and inorganic bases do promote the catalytic reaction, but triethyl-
amine provides the best result.
I
Table 1
Absorption spectral data of porphyrin complexes.
O
Bu
Compound
kmax (log e) (unit: nm)
+
2
434 (5.01), 526 (4.08), 597 (3.77), 653 (2.93)
407 (3.52), 434 (3.68), 567 (2.79)
415 (4.67), 458 (4.41), 567 (3.83), 602 (3.52)
414 (4.47), 443(4.57), 566 (3.78)
405 (4.94), 440 (5.00), 559 (4.22), 597 (3.87)
431 (4.69), 459 (4.56), 584 (3.95)
414 (4.76), 443 (4.65), 560 (3.86), 597 (3.62)
433 (5.11), 459 (4.88), 584 (4.28)
O
8a
8b
8c
8d
9a
9b
9c
9d
9e
ð2Þ
O
Bu
417 (3.97), 454 (3.84), 571 (3.53), 609 (2.51).
440 (4.80), 593 (3.89)
O

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R.-S. Lin et al. / Inorganica Chimica Acta 363 (2010) 3523–3529
Fig. 1. ORTEP plot of 9c.2.5(dmso) (drawn with 30% probability ellipsoids).
Table 3
Table 4
Selected bond distances (Å) and bond angles (°) of 9c.2.5(dmso).
Results of Heck coupling reaction catalyzed by 9c(Zn/Pd)a.
Zn(1)–N(1)
Zn(1)–N(2)
Zn(1)–N(3)
Zn(1)–N(4)
Zn(1)–O(1)
Pd(1)–N(7)
Pd(1)–N(8)
Pd(1)–Cl(1)
Pd(1)–Cl(2)
2.059(4)
2.061(4)
2.049(4)
2.116(4)
2.090(4)
2.028(4)
2.081(4)
2.288(1)
2.288(2)
N(1)–Zn(1)–N(2)
N(2)–Zn(1)–N(3)
N(3)–Zn(1)–N(4)
N(4)–Zn(1)–N(1)
N(1)–Zn(1)–O(1)
N(7)–Pd(1)–N(8)
N(7)–Pd(1)–Cl(1)
N(7)–Pd(1)–Cl(2)
89.3(2)
89.1(2)
88.7(2)
87.5(2)
104.1(2)
81.7(2)
93.8(1)
174.6(1)
Entry
Solvent
Base (mmol)
Temperature (°C)
Yieldb
1
2
3
4
5
6
7
8
DMF
DMSO
H2O
ClCH2CH2Cl
CH3CN
xylene
BMIMc
DMF
NaOAc (6)
NaOAc (6)
NaOAc (6)
NaOAc (6)
NaOAc (6)
NaOAc (6)
NaOAc (6)
(CH3CH2)3N (6)
pyridine (6)
K2CO3 (6)
120
120
reflux
reflux
reflux
120
120
120
120
120
27%
3%
trace
trace
trace
trace
trace
96%
trace
53%
96%
9
10
11
DMF
DMF
DMF
K3PO4 (6)
120
a
Reactions conditions: C6H5I (5 mmol), butyl acrylate (6 mmol), 9c(Zn/Pd)
(0.05 mmol), tetraethylammonium bromide (2 mmol) in solvent (5 mL) for 24 h.
b
Based on the GC analysis.
BMIM: 1-butyl-3-methylimidazolium bromide.
c
The optimized procedure is also applied to other bimetallic pal-
ladium complexes and the results are shown in Fig. 3. As shown in
the diagram, complex 9c(Zn/Pd) appears to be the most active and
the yield reaches to 100% after 30 min. Interestingly, we found that
the reaction did not prove any acceleration under the irradiation of
light. It is noteworthy that the catalytic activities of 9b(Ni/Pd),
9d(Cu/Pd) and 9e(Mg/Pd) do not show any substantially difference
among them, but less active than that of 9c(Zn/Pd). The complex
9a(Co/Pd) is the least active in this series of bimetallic complexes.
This trend is somewhat in line with the relative donating nature of
metalloporphyrins, which is consistent with the observation by
others’ investigation [30,31].
Under the similar reaction conditions, the coupling reaction cat-
alyzed by [(1,10-phenanthroline)PdCl2] appeared to proceed very
slowly; less than 10% of yield was observed after 5 h, indicating
that all bimetallic species acting as pre-catalysts for the coupling
reaction are superior to that of [(1,10-phenanthroline)PdCl2]. In
addition, complex 8c did not show any catalytic activity at all, indi-
cating the requirement of palladium ions for the catalysis. In this
investigation, the variation of metal ions at the porphyrinic site
was found to have considerable effects on the catalytic Mizoroki–
Heck reaction, suggesting that the metalloporphyrin core signifi-
cantly influences the active site of the palladium catalyst. However,
the detail interaction needs further research.
Fig. 2. Crystal packing of 9c 2.5(dmso).

R.-S. Lin et al. / Inorganica Chimica Acta 363 (2010) 3523–3529
3527
Fig. 3. Plot of the yields vs. time for coupling reaction catalyzed by 9a–e.
pound (0.97 g, 90%). This compound was then dissolved in
dichloromethane (30 mL). Concentrated sulfuric acid (8 mL) was
added to the above solution. This mixture was stirred for 8 min
and then poured into ice/water. The CH2Cl2 extracts was separated,
dried over MgSO4 and concentrated. The crude product was
re-crystallized from methanol to yield 4 as purple solids (0.74 g,
84%): 1H NMR (CDCl3): d 9.03 (s, 1H), 9.00 (d, J = 5.2 Hz, 1H), 8.93
(d, J = 5.2 Hz, 1H), 8.88 (m, 2H), 8.71 (m, 2H), 8.25–8.16 (m, 8H),
7.79–7.68 (m, 12H), ꢂ2.63 (s, 2H, –NH), which is essentially iden-
tical to those reported in literature [26].
3. Summary
In conclusion, we have achieved the preparation and character-
ization of heter-bimetallic porphyrin complexes. These complexes
exhibit markedly different catalytic activity on the typical Mizor-
oki–Heck reaction depending on the central metal ions. Such tun-
able nature of porphyrins by central metal ions should allow
further investigation on effective complexes for catalytic reactions.
Although the photo-irradiation did not lead to a better activity of
the metal complex during the coupling catalysis, it does imply
the usefulness of metalloporphyrin acting as a modulating substi-
tuent in other reactions. More fine-tune studies as well as the
interactions of metal ions are currently under investigated.
4.2.2. meso-Tetraphenylporphyrin-a-dione (5)
Concentrated hydrochloric acid (0.14 mL) was added to a mix-
ture of 4 (20 mg, 0.03 mmol) and SnCl2 (70 mg, 0.36 mmol) in
CH2Cl2 under nitrogen atmosphere. The mixture was irritated with
microwave at 60 °C under the power setting on 60 W for 30 min.
After the irritation, the organic layer was separated and dried over
Na2SO4. Silica gel (100 mg) was added to the above solution and
the resulting mixture was shined with light (Bulb light – 100 W)
under oxygen atmosphere for 1 h. Upon crystallization, compound
5 was obtained as brown solids (15 mg, 78%). 1H NMR (CDCl3): d
8.75 (d, J = 5 Hz, 2H), 8.60 (d, J = 5 Hz, 2H), 8.57 (s, 2H), 8.13 (m,
4H), 7.90 (m, 4H), 7.76–7.66 (m, 12H), ꢂ1.99 (s, 2H), which is iden-
tical to those reported in literature [32].
4. Experimental
4.1. General
All reactions and manipulations were performed under a dry
nitrogen atmosphere unless otherwise noted. Tetrahydrofuran
was distilled under nitrogen from sodium/benzophenone. Dichlo-
romethane was dried over CaH2 and distilled under nitrogen. Other
solvents were degassed before use. Chemicals were purchased
from commercial source and used without further purification.
Copper(II) meso-tetraphenylporphyrin 3 and [(1,10-phenanthro-
line)PdCl2] were prepared according to the method reported
[32,28]. A buffer solution of EDTA was prepared by mixing Na2(-
H2EDTA)ꢁ2H2O (372 mg), sodium acetate (0.22 g) and acetic acid
(0.21 mL) in water (100 mL).
Nuclear magnetic resonance spectra were recorded in CDCl3 or
dmso-d6 on a Bruker AVANCE 400 spectrometer. Chemical shifts
are given in parts per million relative to Me4Si for 1H and 13C{1H}
NMR. UV–Vis spectrum was determined on a Hitachi 3310 spec-
trometer. Microwave irradiation was carried out in a Discovery
microwave heating apparatus with temperature controller (CEM
Corp., Matthews, NC).
4.2.3. meso-Tetraphenylporphyrinphenanthroline (2)
Under nitrogen atmosphere, trifluoroacetic acid (25 lL) was
added to a mixture of 5 (24 mg, 0.037 mmol) and 1,10-phenan-
throline-5,6-diamine (7.8 mg, 0.037 mmol) in CH2Cl2 (7 mL). The
mixture was heated to reflux with stirring for 24 h. The color of
solution turned from brown into dark green. Aqueous NaHCO3
(4%) was added to neutralize the acid and the organic layer sepa-
rated. The organic extracts were dried over Na2SO4 and concen-
trated. The residue was chromatographed on silica gel with
elution of CH3OH/CH2Cl2(V:V = 1:10) and a purple-red color band
was collected to yield
2 as purple-red solids (14 mg, 46%).
m.p. > 300 °C; 1H NMR (CDCl3, 400 MHz) d: 9.24 (dd, J = 1.7,
4.3 Hz, 2H), 8.96 (s, 4H), 8.84 (dd, J = 1.7, 8 Hz, 2H), 8.74 (s, 2H),
8.29 (m, 4H), 8.22 (m, 4H), 8.02 (m, 2H), 7.90 (m, 4H), 7.78 (m,
6H), 7.72 (dd, J = 4.3, 8 Hz, 2H), ꢂ2.62 (br, s, 2H, NH); 13C NMR d:
155.2, 151.7, 151.5, 142.0, 141.5, 139.4, 138.2, 134.3, 134.1,
133.9, 133.6, 128.3, 128.2, 128.1, 128.0, 127.8, 127.5, 127.4,
127.1, 127.0, 126.8, 126.7, 123.5, 121.6. UV–Vis (CH2Cl2): kmax
4.2. Synthesis and characterization
4.2.1. Compound (4)
Complex 3 (1.0 g, 1.5 mmol) and acetic anhydride (18 mL) were
dissolved in dichloromethane (250 mL). Under nitrogen atmo-
sphere, Cu(NO3)2 (920 mg, 3.8 mmol) in acetic anhydride (92 mL)
was added and the resulting mixture was stirred at room temper-
ature for 20 h. Water (100 mL) was added and the organic layer
was separated. Upon concentration of the organic extracts, the res-
idue was re-crystallized from methanol to yield the nitro com-
(log e) = 434 (5.01), 526 (4.08), 597 (3.77), 653 (2.93) nm. FAB MS
[M+H+] m/z = calcd. for C56H35N8: 819.30; found: 819.32. Anal. Calc.
for C56H34N8: C, 82.13; H, 4.18; N, 13.68. Found: C, 82.01; H, 3.98;
N, 13.35%.

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R.-S. Lin et al. / Inorganica Chimica Acta 363 (2010) 3523–3529
4.2.4. Bicobalt complex (10)
A mixture of 2 (30 mg, 37
4.2.8. Complex 9a(Co/Pd)
lmol) and CoCl2 (20 mg, 154
l
mol) in
A mixture of 8a (10 mg, 11
lmol) and [(COD)PdCl2] (5.2 mg,
DMF (10 mL) was heated to reflux for 12 h. After the reaction, the
mixture was partitioned in water and dichloromethane. The
dichloromethane layer was dried over Na2SO4 and concentrated
under vacuum to give 10 as purple-red solids (30 mg, 81%): UV–
11 lmol) was placed in a flask capped with septum and the reac-
tion vessel was flashed with nitrogen gas. Degassed CH2Cl2
(3 mL) was syringed into the flask. The solution was stirred at
ambient temperature for 8 h. After the reaction, ether (15 mL)
was added to give the red-brown precipitates, which was collected
and washed with ether and dichloromethane. The obtained solid
was dried under vacuum to provide the desired complex 9a as
Vis (CH2Cl2): kmax (log e) = 411 (4.68), 561 (3.89). FAB Mass: m/z
calcd. for C56H32ClCo2N8 [MꢂCl]+ = 969.1; found: 969.0. Anal. Calc.
for C56H32Cl2Co2N8: C, 66.88; H, 3.21; N, 11.14. Found: C, 66.59; H,
2.92; N, 10.86%.
deep red solids (73%): UV–Vis (CH2Cl2): kmax (log e) = 284 (4.39),
369 (4.32), 431 (4.69), 459 (4.56), 584 (3.95). ESI HRMS m/z calcd.
for C56H32Cl2CoN8Pd: 1053.0494. Found: 1053.0490. Anal. Calc. for
4.2.5. Complex 8a
C56H32Cl2CoN8Pd: C, 63.86; H, 3.06; N, 10.64. Found: C, 63.57; H,
Complex 10 (50 mg, 50
lmol) in CH2Cl2 (10 mL) was added to
2.87; N, 10.54%.
the EDTA buffer solution (10 mL) and the resulting mixture was
stirred at room temperature for 24 h. The organic layer was then
separated, washed with 4% sodium bicarbonate solution, dried
and concentrated to yield 8a as purple solids (35 mg, 80%): UV–
4.2.9. Complex 9b(Ni/Pd)
The preparation of this complex is similar to that for 9a. Reac-
tion of 8b (10 mg, 11 lmol) with [(COD)PdCl2] (5.2 mg, 11 lmol)
Vis (CH2Cl2): kmax (log
e
) = 364 (3.34), 407 (3.52), 434 (3.68), 567
provided the desired complex as pink-red solids (83%): 1H NMR
(CDCl3, 400 MHz) d: 9.68 (d, J = 4.8 Hz, 2H), 8.89 (d, J = 8 Hz, 2H),
8.79 (d, J = 4.8 Hz, 4H), 8.70 (s, 2H), 7.99 (m, 4H), 7.97 (m, 4H),
7.91 (m, 4H), 7.81 (m, 4H), 7.70 (m ,6H); UV–Vis (CH2Cl2): kmax
(2.79); FAB Mass: m/z calcd. for C56H33CoN8 [M+H]+: 876.22;
found: 876.06. Anal. Calc. for C56H32CoN8: C, 76.79; H, 3.68; N,
12.79. Found: C, 76.56; H, 3.38; N, 12.48%.
(log e) = 292 (4.51), 414 (4.76), 443 (4.65), 560 (3.86), 597 (3.62);
FAB Mass m/z calcd. for C56H33Cl2NiN8Pd [M+H]+: 1051.06; found:
1051.05. Anal. Calc. for C56H32Cl2N8NiPd: C, 63.88; H, 3.06; N,
10.64. Found: C, 63.39; H, 2.78; N, 10.46%.
4.2.6. Complex 8b
A mixture of 2 (58 mg, 70.8 lmol) and NiCl2 (18 mg, 141 lmol)
in DMF (10 mL) was heated to reflux for 12 h. After removal of DMF
under vacuum, the residue was dissolved in CH2Cl2 (50 mL) and
then washed with water (100 mL). The organic layer was added
to a EDTA buffer solution (100 mL) and the mixture was stirred
at ambient temperature for 24 h. The organic layer was then sepa-
rated, washed with 4% sodium bicarbonate solution, dried and con-
centrated to yield 8b as pink solids (84%): 1H NMR (CDCl3,
400 MHz) d: 9.22 (d, J = 4.8 Hz, 2H), 8.79 (d, J = 4.8 Hz, 4H), 8.72
(d, J = 8 Hz, 2H), 8.70 (s, 2H), 8.02 (d, J = 7.2 Hz, 4H), 8.00 (d,
J = 7.2 Hz, 4H), 7.90 (m, 2H), 7.78 (m, 4H), 7.66 (m, 8H); 13C NMR
(CDCl3, 100 MHz) d: 151.67, 149.28, 147.45, 147.12, 143.62,
142.08, 141.18, 140.34, 139.88, 137.84, 133.92, 133.31, 133.04,
132.23, 132.03, 131.61, 127.97, 127.88, 127.34, 127.29, 126.92,
4.2.10. Complex 9c(Zn/Pd)
The preparation of this complex is similar to that for 9a. Reac-
tion of 8c (10.1 mg, 11 lmol) with [(COD)PdCl2] (5.2 mg, 11 lmol)
yielded the desired complex as dark green solids (67%). Upon crys-
tallization from CH2Cl2/dmso, complex [9c 2.5(dmso)] was ob-
tained as dark green crystalline solids: 1H NMR (dmso-d6,
400 MHz) d 9.41 (d, J = 4.8 Hz, 2H), 8.86 (d, J = 8 Hz, 2H), 8.79 (d,
J = 4.8 Hz, 4H), 8.73 (s, 2H), 8.22 (m, 10H), 8.08 (m, 2H), 7.89 (m,
4H), 7.79 (m, 6H); UV–Vis (CH2Cl2): kmax (log
(4.48), 433 (5.11), 459 (4.88), 584 (4.28). Anal. Calc. for
56H32Cl2N8ZnPd2.5 (CH3SOCH3): C, 58.38; H, 3.77; N, 8.93. Found:
e) = 276 (4.72), 351
C
C, 58.01; H, 3.49; N, 8.78%.
123.47, 120.83, 116.31; UV–Vis (CH2Cl2): kmax (log
e) = 270
(4.28), 415 (4.67), 458 (4.41), 567 (3.83), 602 (3.52). FAB Mass:
m/z calcd. for C56H33NiN8 [M+H]+: 875.22; found: 875.20. Anal.
Calc. for C56H32NiN8: C, 76.82; H, 3.68; N, 12.80%.
4.2.11. Complex 9d(Cu/Pd)
A solution of 2 (58 mg, 70.8 lmol) and Cu(CH3COO)2 (25 mg,
141 lmol) in methanol/CH2Cl2 (V:V = 1:5) (60 mL) was heated
to reflux for 12 h. After removal of solvents, the residue was dis-
solved in a mixture of dichloromethane (100 mL) and EDTA buffer
solution (100 mL). The resulting mixture was stirred for 24 h. The
organic layer was then separated, washed with 4% sodium bicar-
bonate solution and dried over Na2SO4. Upon concentration, 8d
was obtained as dark-brown solids. UV–Vis (CH2Cl2): kmax (log
4.2.7. Complex 8c
A saturated solution of zinc acetate in methanol (4 mL) was
mixed with a solution of 2 (58 mg, 70.8 lmol) in CH2Cl2 (10 mL).
This solution was heated to reflux for 12 h. The color of solution
turned into dark green. After removal of organic solvents under
vacuum, the residue was dissolved in CH2Cl2 (5 mL) and then
washed with water (10 mL). The organic layer was added to a EDTA
buffer solution (10 mL) and the mixture was stirred at ambient
temperature for 24 h. The organic layer was then separated,
washed with 4% sodium bicarbonate solution, dried and concen-
trated to yield 8c as dark green solids (55%): 1H NMR (CDCl3,
400 MHz) d 9.07 (d, J = 3.2 Hz, 2H), 8.93 (d, J = 4.8 Hz, 4H), 8.87
(s, 2H), 8.83 (d, J = 5.4 Hz, 2H), 8.23 (m, 8H), 8.00 (m, 2H), 7.87
(m, 4H), 7.76 (m, 6H), 7.69 (dd, J = 5.4, 4.8 Hz, 2H); 13C NMR (CDCl3,
100 MHz) d: 152.13, 151.33, 150.00, 149.36, 149.30, 147.20,
142.79, 142.31, 139.87, 137.64, 134.13, 133.99, 133.75, 132.36,
131.80, 131.55, 128.11, 127.57, 127.10, 126.88, 126.51, 123.40,
e) = 405 (4.94), 440 (5.00), 559 (4.22), 597 (3.87). [(COD)PdCl2]
(30 mg, 64 mol) was added to a solution of 8d in dichlorometh-
l
ane with stirring for 8 h. Upon concentration of the volume down
to 5 mL, ether was added and the brown solids precipitated out
from the solution, which was subsequently washed with ether,
dichloromethane and methanol. Complex 9d was obtained brown
solids (85%): UV–Vis (CH2Cl2): kmax (log
(3.97), 454 (3.84), 571 (3.53), 609 (sh). Anal. Calc. for
56H32Cl2CuN8Pd: C, 63.59; H, 3.05; N, 10.59. Found: C, 63.24;
e) = 278 (4.26), 417
C
H, 2.75; N, 10.37%.
4.2.12. Complex 9e(Mg/Pd)
A solution of 2 (13.6 mg, 16.6 mol) and MgBr2ꢁ6H2O (10 mg,
330 mol) in DMF (5 mL) was heated to reflux for 12 h. The color
of solution turned from red into dark green. After removal of the
solvent, the residue was dissolved in dichloromethane (5 mL) and
[(COD)PdCl2] (5 mg, 16.6 mol) was added. The resulting mixture
123.28, 118.18; UV–Vis (CH2Cl2): kmax (log e) = 348 (3.83), 414
(4.47), 44 3(4.57), 566 (3.78). FAB Mass m/z calcd. for C56H33ZnN8
[M+H]+: 881.21; found: 881.01. Anal. Calc. for C56H32ZnN8: C,
76.23; H, 3.66; N, 12.70. Found: C, 75.95; H, 3.28; N, 12.56%.

R.-S. Lin et al. / Inorganica Chimica Acta 363 (2010) 3523–3529
3529
was stirred for another 4 h. Ether (20 mL) was added to the reac-
Appendix A. Supplementary material
tion mixture to yield green precipitates, which was collected and
washed with ether, dichloromethane and methanol (80%): 1H
NMR (dmso-d6, 400 MHz) d 9.43 (d, J = 4.6 Hz, 2H), 8.91 (d,
J = 8 Hz, 2H), 8.69 (d, J = 4.6, 2H), 8.59 (d, J = 8 Hz, 2H), 8.66 (s,
2H), 8.25 (m, 6H), 8.19 (m, 4H), 8.07 (m, 2H), 7.90 (m, 4H), 7.80
CCDC 708936 contains the supplementary crystallographic data
for 9c. These data can be obtained free of charge from The Cam-
bridge Crystallographic Data Centre via http://www.ccdc.cam.a-
c.uk/data_request/cif. Supplementary data associated with this
article can be found, in the online version, at doi:10.1016/
j.ica.2010.07.008.
(m, 6H); UV–Vis (CH2Cl2): kmax (log e) = 279 (4.38), 353 (4.17),
440 (4.8), 593 (3.89). Anal. Calc. for C56H32Cl2MgN8Pd: C, 66.04;
H, 3.17; N, 11.00. Found: C, 65.78; H, 2.87; N, 10.77%.
References
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of 9c 2.5(dmso) is drawn with 30% probability ellipsoids and par-
tial labeling for clear view in Fig. 2. Crystal data for 9c
ꢀ
2.5(dmso): C61H47Cl2N8O2.5PdS2.5Zn, Fw = 1254.89, triclinic, P1 –
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Å,
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= 103.279(10)°, b = 103.075(9)°,
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size 0.25 ꢃ 0.15 ꢃ 0.10 mm3 12 170 reflections collected, 9461
,
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Acknowledgment
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We thank the National Science Council, Taiwan, ROC for the
financial support (NSC97-2113-M-002-013-MY3).