Heterobimetallic Pt(II)-M(I) (M = Cu, Ag) eight-membered macrocyclic complexes with large-bite P,N-ligand bridges

Article abstract of DOI:10.1039/b211301p

Reaction of a new large-bite P,N-ligand, 2-(N-diphenylphosphinomethyl-N- benzyl)aminopyridine (1) with (COD)PtCl₂ and (COD)Pt(OCPh) ₂ give cis-(L)₂PtCl₂ (2) and trans-(L) ₂Pt(OCPh)₂ (3), respectively. Complex 3 reacted with M(I) (M = Cu, Ag) perchlorate using its pyridyl and alkynyl groups to afford a novel type of mixed-metal macrocyclic complexes PtM₂(L) ₂(C≡CPh)₂(ClO₄)₂ (M = Cu, 4; M = Ag, 5). Complex 4 can be converted to the solvated complexes Pt[Cu(solvent)]₂(μ-L)₂(C≡CPh) ₂(ClO₄)₂ (solvent = H₂O,4; CH ₃CN, 4″) by recrystallization of 4 in the corresponding solvents. The crystal structures of complexes 2, 3, 4 and 4″-CH ₂Cl₂ and luminescence properties of 3, 4 and 5 have been determined. The Royal Society of Chemistry 2003.

Full text of DOI:10.1039/b211301p

View Article Online / Journal Homepage / Table of Contents for this issue
Heterobimetallic Pt(II)–M(I) (M ؍ Cu, Ag) eight-membered
macrocyclic complexes with large-bite P,N-ligand bridges†
Qing-Shan Li,* Feng-Bo Xu, Da-Jun Cui, Kai Yu, Xian-Shun Zeng, Xue-Bing Leng,
Hai-Bin Song and Zheng-Zhi Zhang*
State Key Laboratory of Elemento-Organic Chemistry, Nankai University, Tianjin 300071,
P. R. China. E-mail: zzzhang@public.tpt.tj.cn; qli@nankai.edu.cn
Received 14th November 2002, Accepted 24th February 2003
First published as an Advance Article on the web 13th March 2003
Reaction of a new large-bite P,N-ligand, 2-(N-diphenylphosphinomethyl-N-benzyl)aminopyridine (1) with
᎐
᎐
(COD)PtCl and (COD)Pt(C᎐CPh) give cis-(L) PtCl (2) and trans-(L) Pt(C᎐CPh) (3), respectively. Complex 3
᎐
᎐
2
2
2
2
2
2
reacted with M() (M = Cu, Ag) perchlorate using its pyridyl and alkynyl groups to afford a novel type of mixed-
᎐
metal macrocyclic complexes PtM (L) (C᎐CPh) (ClO ) (M = Cu, 4; M = Ag, 5). Complex 4 can be converted to the
᎐
2
2
2
4 2
᎐
solvated complexes Pt[Cu(solvent)] (µ-L) (C᎐CPh) (ClO ) (solvent = H O, 4; CH CN, 4Љ) by recrystallization of 4 in
᎐
2
2
2
4
2
2
3
the corresponding solvents. The crystal structures of complexes 2, 3, 4 and 4ЉؒCH2Cl2 and luminescence properties of
3, 4 and 5 have been determined.
addition of white copper() or silver() perchlorate to a colorless
solution of 3 in CH2Cl2, indicating a fast reaction rate. After
work-up the product was obtained in high yield. When com-
plexes 4 and 5 reacted with Na2S in CH3OH, the coordinated
Cu or Ag atom could be removed from the trinuclear com-
plexes, and complex 3 can be recovered quantitatively (Scheme
Introduction
Although binuclear complexes bridged by some rigid hemilabile
ligands such as (2-diphenylphosphine)pyridine1 and 2,6-bis(di-
phenylphosphino)pyridine2 possess novel structures and have
extensively been studied, they are lacking in reactivity owing to
the limitation of their rigid structural frameworks. Current
attention has been focused on the coordination chemistry of
P–N non-rigid hemilabile ligands, but they usually display
1). All the complexes show satisfactory elemental analysis and
1
have been characterized by FT-IR, H NMR and 31P NMR
spectroscopy, and complex 5 has also been measured by FAB-
MS. Furthermore, complexes 2, 3, 4Ј and 4ЉؒCH2Cl2 were
determined by X-ray single crystal analysis. It is noteworthy
P–N chelating cyclization modes to transition metals. A few
examples show P,N-bridging coordination modes to some
homobimetals.3 Recently we have devoted our efforts to studies
that in complexes 4 and 5, the alkynyl anions were bonded to
on synthetic methods, chemical and physical properties of
different metal ions in the µ-η1,η2-mode and thus two eight-
binuclear complexes bridged by some non-rigid hemilabile
membered bimetallomacrocycles were formed in one molecule
by the cyclization of the large-bite P,N-ligand to different metal
ions.
Interestingly, although bimetallic complex 4 was an air-stable
compound, because of the coordinated unsaturation of Cu
ligands.4 Herein we report on the synthesis and photophysical
properties of two novel heterobimetallic (Pt–Cu and Pt–Ag)
eight-membered macrocycle complexes bridged by a new
P,N-ligand, 2-(N-diphenylphosphinomethyl-N-benzyl)amino-
pyridine (L). Until now, to our best knowledge, there are no
examples of such eight-membered macrocyclic heterobimetallic
complexes bridged by a large-bite P,N-ligand in the literature.
ions, 4 can be converted to new solvent coordinated complexes
᎐
Pt[Cu(H O)] (µ-L) (C᎐CPh) (ClO ) (4Ј) and Pt[Cu(CH CN)] -
᎐
2
᎐
2
2
2
4
2
3
2
(µ-L) (C᎐CPh) (ClO ) (4Љ), upon recrystallization of 4 from
᎐
2
2
4 2
CH2Cl2–wet MeOH and CH2Cl2–CH3CN, respectively. On the
other hand, when heating or under reduced pressure, both
complexes 4Ј and 4Љ lose their coordinated solvents H2O or
MeCN to reform the original heterometallic complex 4 with the
mixed-metal macrocycle framework remaining intact, as shown
in Scheme 2.
Results and discussion
As shown in Scheme 1, the new large-bite P,N-ligand, 2-(N-di-
phenylphosphinomethyl-N-benzyl)aminopyridine (L), 1, was
easily prepared by the reaction of 2-(N-benzyl)aminopyridine
with Ph2PH and (HCHO)n, using a developed method of
the Mannich reaction in acidic medium.4c Reaction of 1
Figs. 1–4 depict the perspective drawings of 2, 3 and the com-
plex cations of 4Ј, 4ЉؒCH2Cl2, respectively, with atomic number-
ing. The crystal data and refinement parameters as well as
selected bond distances and bond angles of these complexes are
collected in Tables 1 and 2, respectively. From these data, it can
be concluded that all the complexes 3, 4Ј and 4ЉؒCH2Cl2 have a
square planar configuration of Pt() with both P atoms and
alkynyl groups in trans-positions, respectively. However, in
complex 2 the platinum atom exhibits a severely distorted
square planar coordination geometry [bond angles, P(1)–Pt(1)–
P(1A) 97.78; P(1)–Pt(1)–Cl(1A) 88.13(14); P(1A)–Pt(1)–Cl(1)
88.13(14); Cl(1A)–Pt(1)–Cl(1) 87.4(2)], due to the interaction
of the two large ligands 1 in cis-positions of the Pt atom. In
complexes 2 and 3, the free pyridyl groups of the ligands 1 are
located in the opposite orientation in their crystal structures,
but in mixed-metal complexes 4Ј and 4ЉؒCH2Cl2, each pyridyl
group and the alkynyl group chelate to a Cu() atom, forming
two mixed-metal macrocycles in one molecule. In addition,
one solvent molecule was attached on each of the Cu atoms.
Each copper atom in 4Ј and 4ЉؒCH2Cl2 is two coordinate with a
᎐
with (COD)Pt(C᎐CPh) gives cis-P-coordinated (L)2PtCl2, 2,
᎐
2
with no trans-product being formed. Complex 2 reacted with
᎐
᎐
NaC᎐CPh to afford trans-(L) Pt(C᎐CPh) , 3. Apparently the
᎐
᎐
2
2
orientation of the two P atoms of the ligand in square planar
configuration around the Pt atom is converted from cis- in 2 to
trans-form in 3 in this process, and the pyridyl N atom of the
ligand remains uncoordinated. Complex 3 can also be prepared
more conveniently and in higher yield (85%) by the reaction of
᎐
ligand 1 with the complex (COD)Pt(C᎐CPh) . Complex 3 with
᎐
2
a trans-P configuration readily reacts with metal ions using its
pyridyl N and alkynyl group. In the preparation of the mixed-
metal macrocyclic complexes 4 and 5, the reaction mixture
immediately turned to a pale-yellow or yellow solution upon
† Electronic supplementary information (ESI) available: UV-vis
absorption spectra and the fluorescence excitation and emission spectra
of complexes
b211301p/
3 and 5. See http://www.rsc.org/suppdata/dt/b2/
T h i s j o u r n a l i s © T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 3
D a l t o n T r a n s . , 2 0 0 3 , 1 5 5 1 – 1 5 5 7
1551

View Article Online
Scheme 1
Scheme 2
bonding interaction to the centre of the C–C acetylenic bond,
while the coordination geometry of platinum atom is approxi-
mate square planar.
are summarized in Table 3. As shown in Table 3, the Cu–C1 and
᎐
Cu–C bond distances and the C –C –C bond angles (–C᎐C–
᎐
2
1
2
3
Ph angles) in complexes 4Ј and 4ЉؒCH2Cl2 are obviously shorter
and less than those found in complexes A–D, respectively,
which indicate that there are stronger interactions between Cu
and the alkynyl groups in complexes 4Ј and 4ЉؒCH2Cl2.
The electronic absorption spectra of the trinuclear complexes
4 (Fig. 5) and 5 show similar patterns with low-lying bands at
Comparison of some bond distances and bond angles in 3, 4Ј
and 4ЉؒCH2Cl2 with those in Pt–Cu complexes with similar
structure, [Pt (µ-dppm) (C᎐CPh) {Cu(CH CN)} ]2ϩ (A),5 [Pt(µ-
᎐
᎐
2
2
4
2ϩ
3
2
᎐
᎐
dppy) (C᎐CPh) {Cu(CH CN) } ]
(B),6 [Pt(bipy)(C᎐CPh) -
᎐
᎐
2
2
3
2
2
᎐
2
t
8
CuBr] (C)7 and [Pt( Bu bipy)(C᎐CC H Me-p) Cu(SCN)] (D)
᎐
2
6
4
2
D a l t o n T r a n s . , 2 0 0 3 , 1 5 5 1 – 1 5 5 7
1552

View Article Online
Fig. 1 Perspective drawing of 2 with atomic numbering scheme. Hydrogen atoms have been omitted for clarity. Thermal ellipsoids are shown at the
30% probability level.
ca. 323 and 319 nm, respectively, similar to that observed for the
mononuclear complex 3 with a band at about 312 nm (Table 4).
With reference to previous spectroscopic studies5,6,9 on the
similar structural complexes, the band at ca. 320 nm is assigned
to a metal-to-ligand charge transfer (MLCT) [5d(Pt)
Ϫ
᎐
π*(PhC᎐C )] transition and the transition is likely to have some
᎐
Ϫ
Ϫ
᎐
᎐
intraligand (IL) character [π(PhC᎐C )
π*(PhC᎐C ), ILCT]
᎐
᎐
mixed into it.
The photophysical data of 3–5 are summarized in Table 4.
Upon photoexcitation at λ > 300 nm, 4 and 5 exhibit two fluor-
escence emission bands in CH2Cl2 solution (1 × 10Ϫ5 M) at
room temperature, at about 400 and 730 nm, respectively.
Compared with the emission spectra of complexes A and B,5,6,9
because of the large energy difference between the two bands,
the higher energy emission bands (408 and 385 nm) observed in
4 and 5 are tentatively assigned as 3MLCT/IL (intraligand
phosphorescence of the bridging diphosphine ligands), similar
to that of the mononuclear complex 3 in 408 nm. The low-
energy emission bands at ca. 730 nm in a very broad range are
proposed to arise from Pt ؒ ؒ ؒ Cu(Ag) interactions. The observ-
ation of the red emission bands at ca. 730 nm in CH2Cl2
suggests that the Pt ؒ ؒ ؒ Cu(Ag) interaction is much stronger
than that in CH2Cl2 solutions of complexes A and B.
Fig. 2 Perspective drawing of 3 with atomic numbering scheme.
Hydrogen atoms have been omitted for clarity. Thermal ellipsoids are
shown at the 30% probability level.
Fig. 3 Perspective drawing of the cation in 4Ј with atomic numbering scheme. Hydrogen atoms are located for the water molecules in compound 4Ј
and the others have been omitted for clarity. Thermal ellipsoids are shown at the 30% probability level.
D a l t o n T r a n s . , 2 0 0 3 , 1 5 5 1 – 1 5 5 7
1553

View Article Online
Table 1 Crystal data and refinement parameters
2
3
4Ј
4ЉؒCH2Cl2
Formula
Mw
Crystal system
Space group
C50H46N4P2PtCl2
1030.84
Orthorhombic
Fdd2
C66H56N4P2Pt
1162.18
Monoclinic
P21/c
C66H60Cl2Cu2N4O10P2Pt
1524.19
C71H64Cl4Cu2N6O8P2Pt
1655.26
Monoclinic
P21/c
Triclinic
¯
P1
a/Å
b/Å
c/Å
α/Њ
19.399(10)
41.78(2)
10.915(5)
90
90
90
8847(8)
8
1.548
9.3607(9)
10.6329(10)
27.735(3)
90
95.618(2)
90
2747.2(5)
2
1.405
10.585(4)
12.007(4)
13.292(5)
108.946(6)
97.064(5)
98.108(6)
1555.9(9)
1
12.274(4)
19.011(6)
16.666(5)
90
92.685(5)
90
3884(2)
2
1.417
β/Њ
γ/Њ
V/Å3
Z
Dc/g cmϪ3
1.627
3.119
µ/mmϪ1
3.405
2.657
2.571
F(000)
Crystal size/mm
λ/Å
θmin, θmax/Њ
T /K
4128
1176
764
1664
0.15 × 0.10 × 0.05
0.71073
1.95, 25.03
293(2)
0.30 × 0.25 × 0.01
0.71073
1.48, 25.39
293(2)
0.20 × 0.20 × 0.06
0.71073
1.65, 23.34
293(2)
0.44 × 0.38 × 0.32
0.71073
1.98, 26.38
293(2)
No. of data collected
No. of unique data
Rint
No. of refined params.
GOF on F 2 a
Final R indicesb
R1
8907
3599
0.0728
267
1.020
5835
2664
0.0369
359
4708
4275
0.0254
394
22034
7926
0.0531
427
1.149
1.071
1.160
0.0565
0.1369
0.0242
0.0555
0.0429
0.0910
0.0686
0.1698
wR2
R indices (all data)
R1
0.0741
0.1466
0.0255
0.0732
1.206, Ϫ0.847
0.0559
0.1068
1.360, Ϫ1.336
0.1115
0.1896
1.407, Ϫ0.776
wR2
Final diff. map/e ÅϪ3
Refinement method
1.800, Ϫ2.515
Full-matrix least-squares on F 2
2
a GOF = [Σw(Fo Ϫ Fc2)2 /(n Ϫ p)]1/2, where n is the number of reflections and p is the number of parameters refined. b R1 = Σ(||Fo| Ϫ |Fc||)/Σ|Fo|;
2
wR2 = 1/[σ2(Fo ) ϩ (0.0691P) ϩ 1.4100P] where P = (Fo2 ϩ 2Fc2)/3.
Fig. 4 Perspective drawing of the cation in 4ЉؒCH2Cl2 with atomic numbering scheme. Hydrogen atoms have been omitted for clarity. Thermal
ellipsoids are shown at the 30% probability level.
UV-absorption spectra were conducted on Perkin-Elmer LS-
50B luminescence spectrometer and Shimadzu UV-1601PC
Experimental
All the reactions were carried out under a prepurified nitrogen
atmosphere using standard Schlenk or vacuum line techniques.
UV-visible spectrophotometer in CH2Cl2 solution (concen-
tration, 1 × 10Ϫ5 M), respectively. Melting points were deter-
The solvents were purified by standard methods. [2-(N-benzyl)-
mined on a Yanaco micromelting point apparatus MP-500.
amino]pyridine,10 (COD)PtCl2,11 (COD)Pt(C᎐CPh)
were
12
᎐
᎐
2
CAUTION: While none of these perchlorate complexes has
proved to be shock sensitive,13 nevertheless proper care should
always be taken.
prepared according to the literature methods. FT-IR spectra
were measured on a Bruker FT-IR Equinox-55 infrared
spectrophotometer; H NMR and 31P{1H} NMR spectra were
1
recorded on Bruker AC-200 NMR spectrometer using CDCl3
as solvent. Elemental analyses were performed by a Yanaco
MT-3 analyzer. Mass spectra were recorded on a VG ZAB-HS
spectrometer. X-Ray crystallographic data were performed on a
Bruker Smart 1000 instrument. The luminescence spectra and
Preparation of the ligand, 2-(N-diphenylphosphinomethyl-
N-benzyl)aminopyridine (1)
To a solution of 2-(N-benzyl)aminopyridine (3.68 g, 20 mmol),
paraformaldehyde (0.75 g, 25 mmol) and glacial acetic acid
D a l t o n T r a n s . , 2 0 0 3 , 1 5 5 1 – 1 5 5 7
1554

View Article Online
Table 2 Selected bond distances (Å) and angles (Њ) with estimated
standard deviations in parentheses
cis-(L)2PtCl2 (2)
Pt(1)–P(1)
Pt(1)–Cl(1)
P(1)–C(1)
P(1)–C(20)
2.260(4)
2.365(4)
1.892(13)
1.801(14)
P(1)–C(14)
N(1)–C(9)
N(1)–C(2)
N(1)–C(1)
1.818(12)
1.367(17)
1.454(17)
1.458(17)
P(1)–Pt(1)–P(1A)
P(1)–Pt(1)–Cl(1A)
P(1A)–Pt(1)–Cl(1A) 169.61(13)
P(1)–Pt(1)–Cl(1)
P(1A)–Pt(1)–Cl(1)
Cl(1A)–Pt(1)–Cl(1)
97.78(18)
88.13(14)
C(1)–P(1)–Pt(1)
C(9)–N(1)–C(2)
C(9)–N(1)–C(1)
C(2)–N(1)–C(1)
N(1)–C(1)–P(1)
N(1)–C(2)–C(3)
112.2(5)
121.7(11)
122.2(11)
115.8(11)
114.1(10)
115.0(12)
169.61(13)
88.13(14)
87.4(2)
Fig. 5 The absorption spectra (a), the excitation spectra (λmonitor = 408
nm) and the fluorescence emission spectra (λex = 323 nm) (b) of the
trinuclear complex 4 in CH2Cl2 solution (concentration, 1 × 10Ϫ5 M).
᎐
trans-(L)2Pt(C᎐CPh)2 (3)
᎐
Pt(1)–C(26)
Pt(1)–P(1)
P(1)–C(13)
N(1)–C(14)
2.015(8)
2.3039(19)
1.885(7)
N(1)–C(19)
N(1)–C(13)
C(26)–C(27)
C(27)–C(28)
1.422(16)
1.435(12)
1.176(10)
1.454(10)
recrystallized from CH2Cl2–CH3OH to give 6.58 g (86%) of
ligand 1 as a white solid powder, mp 83–84 ЊC. Anal. Calc. for
C25H23N2P: C, 78.51; H, 6.06; N, 7.32. Found: C, 78.45; H, 6.14,
N, 7.48%. 1H NMR (CDCl3): 4.45 (s, 2H, CH2 in benzyl), 5.12
(s, 2H, NCH2P), 6.23 (t, 2H, 4Ј and 5Ј-CH in pyridinyl), 6.79 (d,
1H, 3Ј-CH in pyridinyl), 7.01–7.51 (m, 15H, C6H5), 7.82 (d, 1H,
6Ј-CH in pyridinyl) ppm. 31P NMR (CDCl3): Ϫ21.62 (s) ppm.
1.397(14)
C(26)–Pt(1)–C(26A) 180.0(5)
C(14)–N(1)–C(19) 122.9(10)
C(14)–N(1)–C(13) 118.7(8)
C(19)–N(1)–C(13) 118.0(10)
C(26)–Pt(1)–P(1)
C(26A)–Pt(1)–P(1)
C(26)–Pt(1)–P(1A)
C(26A)–Pt(1)–P(1A)
P(1)–Pt(1)–P(1A)
C(13)–P(1)–Pt(1)
91.9(2)
88.1(2)
88.1(2)
91.9(2)
180.00(10)
116.0(3)
N(1)–C(13)–P(1)
113.5(6)
N(1)–C(19)–C(20) 116.3(10)
C(27)–C(26)–Pt(1) 179.0(7)
C(26)–C(27)–C(28) 176.7(9)
Preparation of cis-(L)2PtCl2 (2)
A mixture of 0.374 g Pt(COD)Cl2 (1.0 mmol) and 0.764 g of
ligand 1 (2.0 mmol) in CH2Cl2 (50 ml) was stirred for 2 h at
room temperature. The mixture was filtered and the solvent was
concentrated to a small volume and diethyl ether was sub-
sequently added to the solution to give 0.94 g (91%) of 2 as an
air-stable white solid, mp 230–232 ЊC. The sample for analysis
was further purified by recrystallization from CH2Cl2–n-hex-
ane. Anal. Calc. for C50H46N4P2PtCl2: C, 58.26; H, 4.50; N,
᎐
PtCu2(L)2(C᎐CPh)2(H2O)2(ClO4)2 (4Ј)
᎐
Cu(1)–C(26)
Cu(1)–C(27)
Cu(1)–N(2)
Cu(1)–O(5)
Pt(1)–C(26)
2.003(7)
2.005(7)
2.016(6)
2.038(7)
2.003(8)
Pt(1)–P(1)
2.306(2)
1.892(8)
1.453(9)
1.238(10)
1.463(10)
P(1)–C(13)
N(1)–C(13)
C(26)–C(27)
C(27)–C(28)
C(26)–Cu(1)–C(27)
C(26)–Cu(1)–N(2)
C(27)–Cu(1)–N(2)
C(26)–Cu(1)–O(5)
C(27)–Cu(1)–O(5)
N(2)–Cu(1)–O(5)
36.0(3)
111.9(3)
147.9(3)
152.3(3)
118.1(3)
93.7(3)
C(13)–P(1)–Pt(1)
C(8)–N(1)–C(13)
C(8)–N(2)–Cu(1)
C(12)–N(2)–Cu(1) 109.5(6)
N(2)–C(8)–N(1)
N(1)–C(13)–P(1)
C(27)–C(26)–Pt(1) 174.4(7)
C(27)–C(26)–Cu(1) 72.1(5)
Pt(1)–C(26)–Cu(1) 113.4(4)
C(26)–C(27)–C(28) 163.1(8)
C(26)–C(27)–Cu(1)
C(28)–C(27)–Cu(1) 124.9(6)
120.9(3)
122.7(6)
127.3(6)
1
5.43. Found: C, 57.99; H, 4.35; N, 5.25%. H NMR (CDCl3):
4.41 (s, 4H, CH2 in benzyl), 5.02 (s, 4H, NCH2P), 6.53 (t, 4H,
4Ј- and 5Ј-CH in pyridinyl), 6.70 (d, 2H, 3Ј-CH in pyridinyl),
7.01–7.06 (m, 10H, C6H5 in benzyl), 7.20–7.44 (m, 20H,
P(C6H5)2), 7.99 (d, 2H, 6Ј-CH in pyridinyl) ppm. 31P NMR
(CDCl3): 6.04 (t) ppm, JPt–P = 3700 Hz.
117.2(7)
114.1(5)
C(26A)–Pt(1)–C(26) 180.0(4)
C(26A)–Pt(1)–P(1)
C(26)–Pt(1)–P(1)
C(26A)–Pt(1)–P(1A)
C(26)–Pt(1)–P(1A)
P(1)–Pt(1)–P(1A)
88.4(2)
91.6(2)
91.6(2)
88.4(2)
180.0
᎐
Preparation of trans-(L) Pt(C᎐CPh) (3)
᎐
2
2
71.9(5)
᎐
(a) From the reaction of the ligand L with (COD)Pt(C᎐CPh) .
᎐
2
᎐
A mixture of 0.505 g (COD)Pt(C᎐CPh) (1.0 mmol) and 0.764
᎐
2
᎐
PtCu2(L)2(C᎐CPh)2(CH3CN)2(ClO4)2ؒCH2Cl2 (4ЉؒCH2Cl2)
᎐
g ligand 1 (2.0 mmol) in CH2Cl2 (50 ml) was stirred for 1 h at
room temperature. The mixture was filtered and the solvent was
concentrated to a small volume and diethyl ether was sub-
sequently added to the solution to give 0.98 g (85%) of 3 as
an air-stable white solid, mp 187–188 ЊC. The sample for
analysis was further purified by recrystallization from CH2Cl2–
Et2O. Anal. Calc. for C66H56N4P2Pt: C, 68.21; H, 4.86; N,
4.82. Found: C, 68.09; H, 4.94; N, 4.97%. FT-IR (KBr, disk):
Pt(1)–C(26)
Pt(1)–P(1)
2.024(8)
2.324(2)
1.965(9)
2.018(9)
2.020(10)
Cu(1)–C(26)
P(1)–C(13)
N(1)–C(13)
C(1)–C(2)
2.030(8)
1.897(11)
1.414(12)
1.532(16)
1.249(11)
Cu(1)–N(3)
Cu(1)–N(2)
Cu(1)–C(27)
C(26)–C(27)
C(26A)–Pt(1)–C(26) 180.000(1)
C(27)–Cu(1)–C(26)
C(13)–P(1)–Pt(1)
C(8)–N(1)–C(13)
N(2)–C(8)–N(1)
N(1)–C(13)–P(1)
C(27)–C(26)–Pt(1) 166.7(8)
C(27)–C(26)–Cu(1) 71.6(6)
Pt(1)–C(26)–Cu(1) 119.8(4)
C(26)–C(27)–C(28) 158.4(10)
C(26)–C(27)–Cu(1)
35.9(3)
111.8(3)
121.3(9)
119.5(10)
115.0(7)
C(26A)–Pt(1)–P(1)
C(26)–Pt(1)–P(1)
C(26A)–Pt(1)–P(1A)
C(26)–Pt(1)–P(1A)
P(1)–Pt(1)–P(1A)
N(3)–Cu(1)–N(2)
N(3)–Cu(1)–C(27)
N(2)–Cu(1)–C(27)
N(3)–Cu(1)–C(26)
N(2)–Cu(1)–C(26)
88.2(2)
91.8(2)
91.8(2)
88.2(2)
180.00(13)
99.0(4)
116.6(4)
144.1(3)
152.0(4)
108.9(3)
ν(C᎐C) 2107.6 (vs) cmϪ1. 1H NMR (CDCl3): 4.94 (s, 4H, CH2 in
᎐
᎐
benzyl), 5.50 (s, 4H, NCH2P), 6.33 (t, 4H, 4Ј- and 5Ј-CH in
pyridinyl), 6.86 (d, 2H, 3Ј-CH in pyridinyl), 7.01–7.89 (m, 40H,
C6H5), 7.92 (d, 2H, 6Ј-CH in pyridinyl) ppm. 31P NMR
(CDCl3): 4.44 (t) ppm, JPt–P = 2478 Hz.
72.5(6)
᎐
(b) From the reaction of cis-(L) PtCl (2) with NaC᎐CPh. A
᎐
2
2
C(28)–C(27)–Cu(1) 128.2(6)
solution of phenylacetylene (0.12 ml, 0.11 g, 1.1 mmol) in 5 ml
anhydrous ethanol was added dropwise to a solution of
NaOC2H5 (1.2 mmol, 1 mmol mlϪ1) in anhydrous C2H5OH
(5 ml). The mixture was reacted for 10 min and was transferred
to a suspension of cis-(L)2PtCl2 (0.516 g, 0.5 mmol) in 20 ml of
anhydrous EtOH. The mixture was reacted for 8 h at room
temperature. After removing the solvents in vacuum, the resi-
due was extracted with 150 ml CH2Cl2–H2O (1 : 2). The organic
phase was separated and dried with anhydrous MgSO4. After
removing the CH2Cl2 in vacuum, the crude product was
recrystallized from CH2Cl2–CH3OH to give 0.27 g (46%) of 3.
(2.40 g, 2.4 ml, 40 mmol) in toluene (50 ml), Ph2PH (3.72 g, 3.4
ml, 20 mmol) was added dropwise with stirring at 70–80 ЊC. The
mixture was reacted at 70–80 ЊC until all of paraformaldehyde
had completely disappeared (about 6 h). After cooling the sol-
vent was removed under vacuum and the residue was dissolved
in 100 ml CH2Cl2. A solution of 2.0 g NaOH in 100 ml water
was added to neutralize the acid. Then the organic phase was
separated and dried with anhydrous MgSO4. After removing
the CH2Cl2 in vacuum, the crude product was obtained and
D a l t o n T r a n s . , 2 0 0 3 , 1 5 5 1 – 1 5 5 7
1555

View Article Online
Table 3 Comparison of some bond lengths and angles in 3, 4Ј and 4ЉؒCH2Cl2 with those in structure-similar Pt–Cu complexes containing µ-η1,η2-
᎐
C᎐CPh
᎐
Bond distances/Å
Bond angles/Њ
Pt–C1–C2
᎐
Pt–C1
Cu–C1, Cu–C2
C1᎐᎐C2
C1–C2–C3
᎐
[trans-(L)2Pt(C᎐CPh)2], 3
2.015(8)
2.003(8)
2.024(8)
2.02(1)
2.002(4)
1.996(5)
1.971(12)
1.176(10)
1.238(10)
1.249(11)
1.20(2)
1.212(6)
1.207(6)
1.24(2)
179.0(7)
174.4(7)
166.7(8)
164.8(10)
177.7(3)
172.2(5)
175.5(9)
176.7(9)
163.1(8)
158.4(10)
167.0(1)
169.5(3)
166.1(5)
162.8(11)
᎐
᎐
[Pt(µ–L)2(C᎐CPh)2[Cu(H2O)]2(ClO4)2], 4Ј
2.003(7), 2.005(7)
2.03(8), 2.02(10)
2.12(1), 2.10(4)
2.101(4), 2.173(3)
1.193(5), 2.328(5)
2.156(11), 2.254(11)
᎐
b
᎐
[Pt(µ-L)2(C᎐CPh)2[Cu(CH3CN)]2(ClO4)2], 4Љ
᎐
[Pt2(µ-dppm)2(C᎐CPh)4{Cu(CH3CN)}2]2ϩ, A5 a
᎐
᎐
[Pt(µ-dppy)2(C᎐CPh)2{Cu(CH3CN)2}2]2ϩ, B6 b
᎐
᎐
7 c
᎐
[Pt(bipy)(C᎐CPh)2CuBr], C
᎐
t
8 d
᎐
[Pt( Bu2bipy)(C᎐CC6H4Me-p)2Cu(SCN)], D
᎐
a dppm = Bis(diphenylphosphine)methane. b dppy = 2-Diphenylphosphinopyridine. c bipy = 2,2Ј-Bipyridine. d tBu2bipy = 4,4Ј-Bis-tert-2,2Ј-bipyridine.
Table 4 Absorption and emission data for complexes 3, 4 and 5a
(t, 4H, 4Ј- and 5Ј-CH in pyridinyl), 6.96 (d, 2H, 3Ј-CH in
pyridinyl), 7.05–7.71 (m, 40H, C6H5), 7.74 (d, 2H, 6Ј-CH in
Absorption
Emission
λ/nm
pyridinyl) ppm. 31P NMR (CDCl3): 4.82 (t) ppm, JPt–P = 2684
λ/nm (εmax/dm3 molϪ1 cmϪ1
)
Hz.
3
4
5
252 (16 700), 312 (7480)
249 (12 100), 323 (4060)
245 (9600), 319 (3600)
408
408, 730
385, 740
Reaction of complex 4 with Na2S
A solution of 0.048 g of Na2Sؒ9H2O (0.2 mmol) in 10 ml
CH3OH was added to a solution of 0.12 g 4 (0.072 mmol) in
10 ml CH2Cl2 with stirring and a black precipitate was pro-
duced immediately. The precipitate was filtered off and the sol-
vent was removed under vacuum. The residue was recrystallized
in CH2Cl2–diethyl ether to give complex 3 quantitatively.
A similar reaction for complex 5 can be undertaken to give 3
quantitatively.
a The absorption spectra and fluorescence emission spectra were
recorded with a concentration of 1 × 10Ϫ5 M in dichloromethane at
room temperature.
᎐
Preparation of PtCu (L) (C᎐CPh) (ClO ) (4)
᎐
2
2
2
4 2
A mixture of 0.116 g 3 (0.1 mmol) and 0.066 g Cu(CH3CN)4-
ClO4 (0.2 mmol) in CH2Cl2 (20 ml) was stirred for 0.5 h at room
temperature to give a yellow solution. The mixture was filtered
and the solvent was concentrated to a small volume and diethyl
ether was subsequently added to the solution. The precipitate
was filtered off and dried in vacuum to give 0.12 g (79%) of 4 as
a pale yellow powder, mp 138 ЊC (decomp.). The sample for
analysis was further purified by recrystallization from CH2Cl2–
Et2O. Anal. Calc. for 4, C66H56N4P2PtCu2Cl2O8: C, 53.27; H,
3.79; N, 3.76. Found: C, 53.25; H, 4.02; N, 3.83%. FT-IR (KBr,
X-Ray single-crystal structural determination of complexes
The X-ray quality crystal of complex 2, 3, 4Ј and 4ЉؒCH2Cl2 was
obtained by slow evaporation of its solution in CH2Cl2–hexane,
CH2Cl2–MeOH, CH2Cl2–MeOH and CH2Cl2–MeCN, respect-
ively. For each of complexes 2, 3 and 4Ј, a selected single crystal
was mounted on a Bruker SMART 1000 CCD diffractometer
operating at 50 kV and 30 mA using Mo-Kα radiation (0.71073
Å). For complex 4ЉؒCH2Cl2, the selected crystal was encapsu-
lated in a double-sealed micro-tube and was mounted on the
diffractometer. Data collection at 293 K and reduction were
performed using the SMART and SAINT software,14 with
frames of 0.3Њ oscillation in the range 1.5 < θ < 26Њ (for 4Ј, θ <
24Њ), An empirical absorption correction was applied using the
SADABS program.15 An empirical absorption correction was
applied using ψ-scan data. The structures were solved by direct
methods and all non-hydrogen atoms were subjected to aniso-
tropic refinement by full-matrix least squares on F 2 using the
SHELXTL package.16 Non-hydrogen atoms were subjected to
anisotropic refinement. All hydrogen atoms were generated
geometrically (C–H bond lengths fixed at 0.96 Å), assigned
appropriate isotropic thermal parameters and included in
structure factor calculations. The crystal structure data and
refinement details are summarized in Table 1.
Ϫ1
.
31P NMR (CDCl3): 4.82 (t) ppm,
᎐
disk): ν(C᎐C) 2127.0 (s) cm
᎐
JPt–P = 2996 Hz. Another experiment was similarly proceeded
using 0.116 g of 3 (0.1 mmol) and 0.066 g of Cu(CH3CN)4ClO4
(0.2 mmol), but in a mixed solvent of CH2Cl2–CH3CN (1 : 1), to
give 0.11 g of 4 (74%).
Complex 4 was recrystallized from CH2Cl2–wet MeOH and
CH2Cl2–CH3CN, to give the solvent-coordinated heterometallic
complexes Pt[Cu(H O)] (µ-L) (C᎐CPh) (ClO )
Pt[Cu(CH CN)] (µ-L) (C᎐CPh) (ClO ) (4ЉؒCH2Cl2), respect-
ively. Crystals of complexes 4Ј and 4ЉؒCH2Cl2 suitable for X-ray
structural analysis were easily grown by the slow evaporation of
the corresponding solution of the complex in CH2Cl2–wet
MeOH and CH2Cl2–CH3CN, respectively.
᎐
(4Ј) and
᎐
2
2
2
2
4
2
᎐
᎐
3
2
2
2
4 2
᎐
Preparation of PtAg (L) (C᎐CPh) (ClO ) (5)
᎐
2
2
2
4 2
CCDC reference numbers 197274–197277.
See http://www.rsc.org/suppdata/dt/b2/b211301p/ for crystal-
lographic data in CIF or other electronic format.
A similar procedure, as described above, using 0.116 g of 3 (0.1
mmol) and 0.074 g of Ag(CH3CN)4ClO4 (0.2 mmol) in CH2Cl2
(20 ml), gave 0.125 g (79%) of 5 as a yellow powder, mp 130 ЊC
(decomp.). The sample for analysis was further purified by re-
crystallization from CH2Cl2–Et2O. Anal. Calc. for C66H56N4-
P2PtAg2Cl2O8: C, 50.27; H, 3.58; N, 3.55. Found: C, 50.15; H,
Acknowledgements
Ϫ1
᎐
3.43; N, 3.25%. FT-IR (KBr, disk): ν(C᎐C) 2119.0 (m) cm
.
We are grateful to the National Science Foundation of China
for financial support of this research work (Project Grant No.
20102003).
᎐
FAB-MS, m/z: 1573 (Mϩ), 1474 ([M Ϫ ClO4]ϩ). 1H NMR
(CDCl3): 4.21 (s, 4H, CH2 in benzyl), 4.59 (s, 4H, NCH2P), 6.65
D a l t o n T r a n s . , 2 0 0 3 , 1 5 5 1 – 1 5 5 7
1556

View Article Online
6 V. W. W. Yam, L. P. Chan and T. F. Lai, J. Chem. Soc., Dalton Trans.,
1993, 2075.
References
1 See, for example: (a) Z. Z. Zhang and H. Cheng, Coord. Chem. Rev.,
1996, 147, 1; (b) P. Espinet and K. Soulantica, Coord. Chem. Rev.,
1999, 193–195, 499.
7 H. Lang, A. del Villar and G. Rheinwald, J. Organomet. Chem.,
1999, 587, 284.
8 C. J. Adams and P. R. Raithby, J. Organomet. Chem., 1999, 578, 178.
9 V. W. W. Yam, K. K. W. Lo and K. M. C. Wong, J. Organomet.
Chem., 1999, 578, 3.
10 O. Kemal and C. B. Reese, J. Chem. Soc., Perkin Trans. 1, 1981, 5,
1569–73.
11 D. Drew and J. R. Doyle, Inorg. Synth., 1972, 13, 47.
12 (a) M. Herberhold, T. Schmalz, W. Milius and B. Wrackmeyer,
J. Organomet. Chem., 2002, 641, 173–84; (b) R. J. Cross and
M. F. Davidson, J. Chem. Soc., Dalton Trans., 1986, 1987.
13 (a) W. C. Wolsey, J. Chem. Educ., 1973, 50, A335; (b) K. N.
Raymond, Chem. Eng. News, 1983, 61, 4.
14 SMART 5.0 and SAINT 4.0 for Windows NT, Area Detector
Control and Integration Software, Bruker Analytical X-Ray
Systems, Inc., Madison, WI, USA, 1998.
15 G. M. Sheldrick, SADABS, Program for Empirical Absorption
Correction of Area Detector Data,University of Göttingen,
Germany, 1996.
16 G. M. Sheldrick, SHELXTL 5.10 for Windows NT, Structure
Determination Software Programs, Bruker Analytical X-Ray
Systems, Inc., Madison, WI, USA, 1997.
2 See, for example: (a) A. L. Balch, Prog. Inorg. Chem., 1993, 41, 239;
(b) H. B. Song, Z. Z. Zhang, Z. Hui, M. C. Che and T. C. W. Mak,
Inorg. Chem., 2002, 41, 3146; (c) H. B. Song, Z. Z. Zhang and
T. C. W. Mak, Inorg. Chem., 2001, 40, 5928; (d ) S. M. Kuang,
Z. Z. Zhang, Q. G. Wang and T. C. W. Mak, J. Chem. Soc.,
Dalton Trans., 1998, 2927; (e) H. B. Song, Q. M. Wang, Z. Z.
Zhang and T. C. W. Mak, J. Chem. Soc., Dalton Trans., 2001,
1658.
3 (a) S. E. Durrn, M. B. Smith, A. M. A. Shawin and J. W. Steed,
J. Chem. Soc., Dalton Trans., 2000, 2778; (b) H. B. Song,
Z. Z. Zhang and T. C. W. Mak, J. Chem. Soc., Dalton Trans., 2002,
1336.
4 (a) H. B. Song, Q. M. Wang, Z. Z. Zhang and T. C. W. Mak,
J. Organomet. Chem., 2000, 605, 15; (b) H. B. Song, Z. Z. Zhang and
T. C. W. Mak, New. J. Chem., 2002, 26, 113; (c) D. J. Cui, Q. S. Li,
F. B. Xu, X. B. Leng, X. S. Zeng and Z. Z. Zhang, Organometallics,
2001, 20, 4126.
5 V. W. W. Yam, K. L. Yu, K. M. C. Wong and K. K. Cheung,
Organometallics, 2001, 20, 721.
D a l t o n T r a n s . , 2 0 0 3 , 1 5 5 1 – 1 5 5 7
1557