Reaction of [Cu2(μ-Ph2Ppypz)2(MeCN)2](ClO4)2 (Ph2Ppypz=(2-diphenylphosphino-6-pyrazol-1-yl)pyridine) with Fe(CO)42- and X- (X=Cl, I, MeCO2</

Article abstract of DOI:10.1016/S0022-328X(98)00418-5

[Cu₂(μ-Ph₂Ppypz)₂(MeCN)₂](ClO₄)₂ (Ph₂Ppypz=(2-diphenylphosphino-6-pyrazol-1-yl)pyridine) reacts with Fe(CO)₄^2- in tetrahydrofuran to give [Cu₂(μ-

Full text of DOI:10.1016/S0022-328X(98)00418-5

Journal of Organometallic Chemistry 558 (1998) 131–138
Reaction of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
(Ph2Ppypz=(2-diphenylphosphino-6-pyrazol-1-yl)pyridine) with
Fe(CO)24− and X− (X=Cl, I, MeCO2 and pyrazolate)
Shan-Ming Kuang a, Zheng-Zhi Zhang b, Qi-Guang Wang a, Thomas C.W. Mak a,*
a Department of Chemistry, The Chinese Uni6ersity of Hong Kong, Shatin. New Territories. Hong Kong
b Elemento-Organic Chemistry Laboratory, Nankai Uni6ersity, Tianjin, China
Received 28 October 1997
Abstract
[Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2 (Ph2Ppypz=(2-diphenylphosphino-6-pyrazol-1-yl)pyridine) reacts with Fe(CO)24− in te-
trahydrofuran to give [Cu2(v-Ph2Ppypz)2(MeCN)2](Fe(CO)4), 1, and with X− in acetonitrile or tetrahydrofuran at room
temperature to afford [Cu2(v-Ph2Ppypz)2(v-X)](ClO4) (X=Cl, 2; I, 3; MeCO2, 4; pyrazolate, 5). The crystal structures of 1,
3·Et2O, 4·Et2O and 5 have been determined by X-ray crystallography. © 1998 Elsevier Science S.A. All rights reserved.
Keywords: Binuclear copper(I) complexes; Bridging phosphine ligand; Iron carbonylate anion; Pyrazolate
1. Introduction
thiocyanate (v-1, 1-SCN) bridging [3]. We report here
the reaction of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
with Fe(CO)24− in tetrahydrofuran to give [Cu2(v-
Ph2Ppypz)2(MeCN)2](Fe(CO)4), 1 and with X− in ace-
tonitrile or tetrahydrofuran at room temperature to
afford [Cu2(v-Ph2Ppypz)2(v-X)](ClO4)(X=Cl, 2; I, 3;
MeCO2, 4; pyrazolate (pz), 5). The crystal structures of
1, 3·Et2O, 4·Et2O and 5 have been determined by
X-ray crystallography.
Increasing interest in polynuclear copper(I) chemistry
is mainly associated with studies related to the reactiv-
ity of molecular oxygen, not only in biological systems
but also in catalytic oxidation and dioxygen-mediated
processes [1]. The major effort in this field is to design
binucleating ligands that hold two metal atoms at an
appropriate distance apart so as to provide twin-site
binding to small molecules and organic functionalities.
Previous works from our laboratories have demon-
strated the reactions of [Cu2(v-Ph2Ppypz)2(MeCN)2]-
(ClO4)2 (Ph2Ppypz=(2-diphenylphosphino-6-pyrazol-
1-yl)pyridine) with LiCꢀCPh to give [(Cu2(v-
Ph2Ppypz)2(v2-p1-CꢀCPh)](ClO4), with dimethyl acetyl-
2. Experimental section
2.1. General procedure, measurement, and materials
All reactions were routinely carried out under nitro-
gen atmosphere using Schlenk techniques. The solvents
were purified by standard methods. IR spectra were
measured on a Perkin Elmer 1600 spectrometer. The
1H-NMR spectra were recorded on a Bruker-300 NMR
spectrometer using Si(Me4) as the external standard and
enedicarboxylate
to
yield
[Cu2(v-MeO2CCꢀ
CCO2Me)(v-Ph2Ppypz)2](ClO4)2 [2], and with NaX
(X=N3, SCN) to afford [Cu2(v-Ph2Ppypz)2(v-
X)](ClO4), which exhibits unusual azide (v-1, 1-N3) and
* Corresponding author.
0022-328X/98/$19.00 © 1998 Elsevier Science S.A. All rights reserved.
PII S0022-328X(98)00418-5

132
S.-M. Kuang et al. / Journal of Organometallic Chemistry 558 (1998) 131–138
Table 1
Crystal data for 1, 3 Et2O, 4Et2O and 5
Formula
C48H38Cu2FeN8O C40H32ClCu2IN6O4P2 ·Et2O(3 C42H35ClCu2N6O6P2 ·Et2O
C43H35ClCu2N8O4P2
(5)
952.26
4P2 (1)
1035.73
294
·Et2O)
108 6.21
294
(4·Et2O)
1018.35
294
Formula weight
Temperature (K)
Crystal system
Sace group
294
Triclinic
P1 (no. 2)
Monoclinic
P21/c (no. 14)
Monoclinic
P21/n (no. 14)
Orthorhombic
Pca21 (no. 29)
Unit cell dimensions
˚
a (A)
9.865(2)
10.887(2)
12.864(3)
66.80 (3)
88.29 (3)
86.41 (3)
1267.4 (6)
1
25.070 (5)
12.725 (3)
15.047 (3)
90
105.11 (3)
90
13.607 (3)
19.657(3)
17.698 (4)
90
99.01(1)
90
19.661 (5)
9.592 (3)
22.913 (3)
90
90
90
4322 (2)
4
˚
b (A)
˚
c (A)
h (°)
i (°)
k (°)
3
˚
V (A )
4634 (2)
4
4675 (2)
4
Z
F(000)
528
1.569
0.71073
1.515
2184
1.451
0.71073
1.76
2096
1.448
0.71073
1.09
1944
1.464
0.71073
1.17
Dcalc (g cm−3
)
˚
u (A) (Mo–Kh)
v (cm−1
)
Two theta range for data collection (°) 4–52
4–52
3–53
4–52
Goodness-of-fit index
1.86
1.34
1.46
1.61
No. of unique reflections
4084 (Rint
0.00%)
=
6576 (Rint=2.90%)
9670 (Rint=2.90%)
7230 (Rint=3.47%)
No. of observed reflection (ꢀFꢀ]4|(F)) 3854
5214
554
0.050
0.080
3248
552
0.071
0.195
6922
541
0.052
0.055
No. of variables, p
334
Rfa
0.044
0.049
RwFb2
a RF=S(ꢀFoꢀ−ꢀFcꢀ)/SꢀFoꢀ
2
b RwF2=[{Sw(ꢀFoꢀ−ꢀFcꢀ)2}/{SwꢀFoꢀ }]1/2
CDCl3 as solvent. The 31P{1H}-NMR spectra were
recorded on a Bruker-500 NMR spectrometer at 202.45
MHz using 85% H3PO4 as the external standard and
CDCl3 as solvent. Ph2Ppypz [2], Na2Fe(CO)4 [4] and
[Cu(MeCN)4](ClO4) [5] were prepared from literature
procedures.
LiCl or KI, (0.30 mmol) and the mixture was stirred at
r.t. for 24 h. Filtration followed by vapor diffusion of
Et2O into a concentrated solution afforded yellow crys-
tals of [Cu2(v-Ph2Ppypz)2(v-Cl)](ClO4), 2, (0.21 g, 76%.
Anal. Calcd. for C40H32Cl2Cu2N6O4P2 ·H2O: C, 51.18;
H, 3.65; N, 8.96. Found: C, 51.54; H, 3.48; N, 9.00.
1H-NMR: 8.48 (d, J=0.7Hz, 2H), 8.20 (m, 2H)
8.06(m, 4H) 7.28 (m, 20H) 7.00 (m, 2H) 6.56 (t, J=
0.90Hz, 2H); 31P(1H)-NMR: l 3.5 ppm) or [Cu2(v-
Ph2Ppypz)2(v-I)](ClO4)·Et2O, 3·Et2O (0.22 g, 73%.
Anal. Calcd. for C40H32ClCu2IN6O4P2: C, 47.47; H,
3.19; N, 8.31. Found: C, 47.75; H, 3.47; N, 8.22.
1H-NMR: l 8.65 (d, J=0.3Hz, 2H) 8.21 (m, 4H) 7.28
(m, 20H) 6.97 (m, 4H) 6.50 (d, J=0.4Hz) 3.45 (t,
J=0.4 Hz, 2H) 1.21 (t, J=0.4Hz, 3H). 31P(1H)-NMR:
l 3.5 ppm).
2.1.1. Reaction of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
with Na2Fe(CO)4
To a solution of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
(0.32 g, 0.3 mmol) in 30ml THF was added solid
Na2Fe(CO)4 (0.06 g, 0.30 mmol), and the mixture was
stirred at r.t. for 8 h. Filtration followed by vapor
diffusion of Et2O into a concentrated solution afforded
orange crystals of [Cu2(v-Ph2Ppypz)2(MeCN)2]-
(Fe(CO)4), 1 (0.17 g, 67% yield). Anal. Calc. for
C48H38Cu2FeN8O4P2: C, 55.66; H, 3.70; N, 10.82.
Found: C, 55.97; H, 3.72, N, 10.49. IR: w(CO) 2054,
2.1.3. Reaction of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
1
1986, 1882cm−1. H-NMR: l 8.45 (d, J=0.7Hz, 2H),
with MeCO2
−
A solution of NaO2CMe (25 mg, 0.30 mmol) in 10 ml
THF-EtOH(1:1) was added to a solution of [Cu2(v-
Ph2Ppypz)2(MeCN)2](ClO4)2 (0.32 g, 0.3 mmol) in 30
ml THF. The resulting mixture was stirred at r.t. for 8
h. Subsequent diffusion of diethyl ether into the con-
centrated solution gave yellow crystals of [Cu2(v-
Ph2Ppypz)2(v-O2CMe)](ClO4), 4 (0.24 g, 85%). Anal.
Calcd. for C42H35ClCu2N6O6P2: C, 53.42; H, 3.74; N,
7.90 (m, 2H) 7.78 (m, 4H) 7.18 (m, 20H) 6.73 (m, 2H)
6.67 (t, J=1.0Hz, 2H) 2.28 (s, 6H); 31P(1H)-NMR: l
8.9 ppm.
2.1.2. Reaction of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
with X− (X=Cl, I)
To a solution of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
(0.32 g, 0.3 mmol) in 30 ml MeCN was added solid

S.-M. Kuang et al. / Journal of Organometallic Chemistry 558 (1998) 131–138
133
Table 3
8.90. Found: C, 53.45; H, 3.70; N, 8.79. IR: w(O2CMe)
1558, 1462 cm−1. 1H-NMR: l 8.48 (s, 2H) 8.05 (m, 4H)
7.10 (m, 20H) 6.67 (m, 4H) 6.50 (t, J=0.4Hz, 2H) 3.45
(t, J=0.4 Hz, 2H) 1.96 (s, 3H) 1.21 (t, J=0.4Hz, 3H).
31P(1H)-NMR: l 21.2 ppm.
Atomic coordinates of complex 1 (×105 for Cu and Fe; ×104 for
˚
other atoms) and equivalent isotropic displacement coefficients (A×
104 for Cu and Fe; A×10 for other atoms)
3
˚
Atom
x
y
z
Ueq
Cu(1)
Fe(1)
P(1)
O(1)
O(2)
38714(3)
88058(5)
5382(1)
8551(3)
10690(3)
10309(3)
6319(3)
3171(2)
3400(2)
3879(2)
2178(3)
3131(3)
3340(3)
3508(3)
3494(2)
3191(3)
3313(3)
6245(3)
5979(2)
5385(3)
4732(3)
3350(3)
2591(3)
3235(3)
4619(3)
8117(3)
9231(3)
9189(3)
8030(3)
6916(3)
6942(3)
1248(3)
43(3)
55344(3)
115733(5)
7087(1)
10723(3)
13676(3)
9402(3)
12530(3)
5596(2)
4357(2)
3501(2)
5870(2)
6434(3)
5739(3)
4431(3)
3242(2)
1978(3)
934(3)
8832(3)
7537(2)
9626(3)
10773(3)
10977(3)
10041(3)
8898(3)
8667(2)
7480(3)
7315(3)
6502(3)
5837(3)
5990(3)
6830(2)
6119(3)
6 426(3)
12131(3)
11039(3)
10280(3)
12838(3)
40178(3)
22281(5)
3531(1)
362(2)
1242(3)
3992(3)
2882(4)
2422(2)
2410(2)
4320(2)
4823(2)
1341(2)
636(3)
1331(2)
3448(2)
3524(2)
4561(3)
4526(2)
4658(2)
1697(3)
925(3)
501(1)
679(1)
44(1)
103(1)
116(1)
115(1)
173(1)
54(1)
50(1)
44(1)
62(1)
61(1)
73(1)
64(1)
47(1)
55(1)
63(1)
57(1)
45(1)
68(1)
80(1)
70(1)
67(1)
60(1)
48(1)
61(1)
73(1)
70(1)
67(1)
57(1)
48(1)
59(1)
79(1)
79(1)
68(1)
71(1)
68(1)
2.1.4. Reaction of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
with pyrazolate (pz)
To a solution of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
(0.32 g, 0.3 mmol) in 30 ml THF was added an equimo-
lar amount of lithium pyrazolate (prepared in situ by
the treatment of a THF solution of pyrazole with
LinBu) at r.t. The resulting mixture was stirred at r.t.
for 4 h. Subsequent diffusion of diethyl ether into the
concentrated solution gave orange crystals of [Cu2(v-
Ph2Ppypz)2(v-pz)](ClO4), 5 (0.20 g, 63%). Anal. Calcd.
for C43H35ClCu2N8O4P2: C, 54.23; H, 3.70; N,
O(3)
O(4)
N(1)
N(2)
N(3)
N(4)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(26)
C(23)
C(25)
C(24)
1
11.77.Found: C, 54.37; H, 3.49; N, 11.73. H-NMR: l
8.48 (d, J=0.6Hz, 2H) 8.04 (m, 4H) 7.10 (m, 20H) 6.87
(m, 4H) 6.70 (m, 3H) 6.52 (t, J=0.4Hz, 2H). 31P(1H)-
NMR: l −0.5 ppm.
938(3)
1732(3)
2536(3)
2512(2)
2791(3)
2168(3)
1572(3)
1618(3)
2239(2)
2822(2)
5254(2)
5817(3)
2612(3)
1117(3)
3292(3)
1635(3)
Table 2
˚
Selected bond lengths (A) and angle (°) in complexes 1, 3·Et2O,
4·Et2O and 5
Complex 1
Cu(1)· · ·Cu(1a)
Cu(1)ꢁN(3)
P(1)ꢁCu(1)ꢁN(1)
P(1)ꢁCu(1)ꢁN(4)
N(1)ꢁCu(1)ꢁN(4)
3.322(1)
2.095(5)
104.0(1)
116.3(1)
105.3(1)
Cu(1)ꢁN(1)
Cu(1)ꢁN(4)
P(1)ꢁCu(1)ꢁN(3)
N(1)ꢁCu(1)ꢁN(3)
N(3)ꢁCu(1)ꢁN(4)
C(25)ꢁFe(1)ꢁC(26)
2.121(5)
2.028(3)
136.5(1)
78.0(1)
104.4(1)
116.3(2)
7333(3)
8648(3)
9693(3)
9949(3)
C(24)ꢁFe(1)ꢁC(25) 105.8(1)
Complex 3·Et2O
Cu(1)ꢁCu(2)
Cu(1)ꢁN(4)
Cu(1)ꢁN(6)
Cu(1)ꢁI(1)
P(1)ꢁCu(1)ꢁN(4)
P(1)ꢁCu(1)ꢁN(6)
P(1)ꢁCu(1)ꢁI(1)
N(4)ꢁCu(1)ꢁI(1)
N(6)ꢁCu(1)ꢁCl(1)
N(4)ꢁCu(1)ꢁN(6)
2.832(1)
2.050(1)
2.154(1)
2.659(1)
122.6(1)
131.5(1)
112.3(1)
105.2(1)
98.3(1)
Cu(2)ꢁN(1)
Cu(2)ꢁN(3)
Cu(2)ꢁI(1)
P(2)ꢁCu(2)ꢁN(1)
P(2)ꢁCu(2)ꢁN(3)
P(2)ꢁCu(2)ꢁI(1)
N(1)ꢁCu(2)ꢁI(1)
N(3)ꢁCu(2)ꢁCl(1)
N(1)ꢁCu(2)ꢁN(3)
2.089(2)
2.089(1)
2.675(1)
112.5(1)
137.2(1)
115.2(1)
106.9(1)
99.0(1)
2.2. X-ray crystallography
The intensity data of 1, 3·Et2O and 5 were collected
at 294 K on a Rigaku RAXIS IIC imaging-plate dif-
fractometer using Mo–Kh radiation (u=0.71073 A)
77.8(1)
79.3(1)
˚
Complex 4·Et2O
Cu(1)ꢁCu(2)
Cu(1)ꢁO(1)
Cu(2)ꢁCu(1)ꢁO(1) 79.3(1)
N(1)ꢁCu(1)ꢁN(3)
from a rotating-anode generator operating at 50 KV
and 90 mA (2qmin=4°, 2qmax=52°, 36 5° oscillation
frames in the range of 0–180°, exposure 8 min per
frame) [6]. A self-consistent semi-empirical absorption
correction based on Fourier coefficient fitting of sym-
metry-equivalent reflections was applied using the AB-
SCOR [7] program. Intensity data of 4·Et2O were
collected in the variable ꢀ-scan mode on a four-circle
diffractometer (Simens R3 m/V) using Mo–Kh radia-
2.924(2)
2.020(4)
Cu(2)ꢁO(2)
Cu(1)ꢁCu(2)ꢁO(2)
N(4)ꢁCu(2)ꢁN(6)
2.023(5)
80.0(1)
77.0(2)
76.8(2)
Complex 5
Cu(1)ꢁCu(2)
Cu(1)ꢁN(3)
Cu(2)ꢁN(4)
Cu(2)ꢁN(4)
Cu(2)ꢁCu(1)ꢁN(7) 65.7(1)
N(1)ꢁCu(1)ꢁN(3) 77.7(1)
2.930(2)
2.113(1)
2.056(2)
1.998(2)
Cu(1)ꢁN(1)
Cu(1)ꢁN(7)
Cu(2)ꢁN(6)
2.078(2)
2.016(2)
2.158(2)
Cu(1)ꢁCu(2)ꢁN(8)
N(4)ꢁCu(2)ꢁN(6)
66.3(1)
78.5(1)
˚
tion (u=0.71073 A, 50 kV, 25 mA) (2qmin=3°,
2qmax=53°) at 294 K.

134
S.-M. Kuang et al. / Journal of Organometallic Chemistry 558 (1998) 131–138
Table 4
Table 5
Atomic coordinates of complex 3·Et2O (×105 for Cu and I; ×104
Atomic coordinates of complex 4·Et2O (×105 for Cu; ×104 for
˚
other atoms) and equivalent isotropic displacement coefficients (A×
3
for other atoms) and equivalent isotropic displacement coefficients
4
3
(A×10 for Cu and I; A×10 for other atoms)
104 for Cu; A×10 for other atoms)
˚
˚
˚
Atoms
x
y
z
Ueq
Atoms
x
y
z
Ueq
Cu(1)
Cu(2)
I(1)
P(1)
P(2)
Cl(1)
Cl(2)
O(1)
O(2)
O(3)
O(4)
N(1)
N(2)
N(3)
N(4)
N(5)
N(6)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(37)
C(38)
C(39)
C(40)
O(1W)
C(1W)
C(2W)
O(2W)
C(3W)
C(4W)
22216(1)
24743(1)
21234(1)
3086(1)
1862(1)
5000
30298(2)
29292(2)
46956(1)
2482(1)
1662(1)
3738(1)
1219(1)
4297(3)
3115(4)
598(2)
1885(2)
3353(2)
3493(1)
3073(1)
3363(1)
2876(1)
2203(1)
3540(2)
3804(2)
3770(2)
3425(2)
3759(2)
3741(2)
3380(2)
3039(2)
3589(2)
3830(2)
3312(2)
2503(2)
2241(2)
2802(2)
408(2)
14214(1)
33667(1)
24334(1)
1689(1)
3174(1)
7500
701(1)
758(1)
842(1)
70(1)
72(1)
129(1)
72(1)
277(2)
289(2)
145(1)
148(1)
82(1)
80(1)
68(1)
77(1)
70(1)
63(1)
87(1)
97(1)
91(1)
Cu(1)
Cu(2)
P(1)
P(2)
Cl(1)
O(1)
O(2)
O(3)
O(4)
O(5)
O(6)
O(7)
N(1)
N(2)
N(3)
N(4)
N(5)
N(6)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
70687(9)
61207(9)
8385(2)
5835(2)
8072(2)
5951(3)
5426(3)
8615(3)
7382(3)
7568(3)
8653(3)
9063(3)
7416(3)
6898(3)
6299(3)
5660(3)
6295(3)
7359(3)
7949(3)
7767(3)
7111(3)
6261(3)
5647(3)
5022(3)
5042(3)
5725(3)
6730(3)
6882(3)
7479(3)
7951(3)
7833(3)
7236(3)
4662(3)
3879(3)
2935(3)
2799(3)
3549(3)
4479(3)
4913(3)
5049(3)
5933(3)
7194(3)
7844(3)
8705(3)
8896(3)
8217(3)
9332(3)
10320(3)
10977(3)
10617(3)
9620(3)
8978(3)
9058(3)
9070(3)
9599(3)
10116(3)
10114(3)
9596(3)
5417(3)
4645(3)
10656(3)
9745(3)
7958(3)
7545(3)
−639(7)
5905(7)
75(2)
1380(1)
145(2)
−724(2)
−322(2)
−314(3)
−163(3)
450(3)
86692(7)
72577(7)
8141(1)
8053(1)
3316(2)
8325(3)
7153(3)
2959(3)
3675(3)
2630(3)
3738(3)
5426(3)
9808(3)
10298(3)
9326(3)
6087(3)
5638(3)
6736(3)
10242(3)
10991(3)
11005(3)
10036(3)
10496(3)
10202(3)
9456(3)
9045(3)
8226(3)
8877(3)
8921(3)
8320(3)
7682(3)
7612(3)
7763(3)
7394(3)
7198(3)
7382(3)
7720(3)
7921(3)
5605(3)
4835(3)
4866(3)
5982(3)
5540(3)
5902(3)
6695(3)
7098(3)
8439(3)
8586(3)
8786(3)
8850(3)
8705(3)
8522(3)
8300(3)
8982(3)
9129(3)
8628(3)
7935(3)
7767(3)
7687(3)
7520(3)
5599(3)
5410(3)
4848(3)
5379(3)
478(1)
484(1)
44(1)
44(1)
91(1)
58(1)
63(1)
253(1)
147(1)
152(1)
147(1)
214(1)
54(1)
42(1)
37(1)
60(1)
59(1)
42(1)
66(1)
67(1)
57(1)
43(1)
53(1)
59(1)
53(1)
38(1)
48(1)
65(1)
87(1)
81(1)
79(1)
61(1)
48(1)
68(1)
86(1)
96(1)
79(1)
69(1)
84(1)
97(1)
83(1)
47(1)
61(1)
66(1)
54(1)
44(1)
47(1)
64(1)
76(1)
75(1)
69(1)
57(1)
37(1)
61(1)
74(1)
71(1)
73(1)
58(1)
53(1)
76(1)
205(1)
241(1)
308(1)
226(1)
0
7500
4827(1)
4555(1)
352(1)
6740(2)
75 55(2)
8177(1)
7070(1)
4748(1)
4969(1)
3456(1)
124(1)
−87(1)
1390(1)
5534(1)
6239(1)
5868(1)
4266(1)
4408(2)
3677(2)
2828(1)
2741(1)
199(1)
−509(2)
−592(2)
−7(2)
689(2)
807(1)
1364(2)
1443(2)
2004(2)
2517(2)
2455(2)
1876(1)
−597(1)
−1271(2)
−927(1)
589(1)
294(1)
581(3)
2778(1)
3344(1)
3317(1)
1745(1)
1239(1)
1467(1)
2647(1)
3112(1)
3542(1)
3619(1)
4163(1)
4394(1)
4079(1)
3545(1)
3234(1)
3484(1)
3929(1)
4140(1)
3895(1)
3448(1)
2804(1)
2888(1)
3341(1)
3735(1)
3676(1)
3204(1)
1732(1)
1234(1)
924(1)
2141(3)
−461(3)
−132(3)
613(3)
833(3)
582(3)
279(3)
−922(3)
−911(3)
−407(3)
410(3)
74(1)
92(1)
101(1)
87(1)
72(1)
695(3)
1208(3)
1425(3)
1121(3)
2069(3)
2458(3)
3031(3)
3211(3)
2812(3)
2243(3)
1804(3)
1431(3)
1730(3)
2398(3)
2772(3)
2484(3)
1072(3)
974(3)
88(1)
108(1)
121(1)
112(1)
95(1)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(37)
C(38)
C(39)
C(40)
C(41)
C(42)
C(43)
C(44)
C(45)
C(46)
73(1)
101(1)
142(1)
153(1)
137(1)
108(1)
80(1)
94(1)
105(1)
87(1)
65(1)
81(1)
84(1)
80(1)
−654(2)
−1078(2)
−437(2)
646(2)
1083(2)
3963(2)
3877(2)
3188(2)
2284(1)
1834(2)
1368(2)
1309(2)
1723(2)
−541(2)
−1551(2)
−1789(3)
−985(3)
44(2)
1081(1)
566(1)
421(1)
645(3)
278(3)
5(3)
414(1)
1140(1)
1994(1)
2090(1)
2857(2)
2978(2)
3443(2)
3871(2)
3748(2)
3252(1)
4589(1)
5287(2)
5439(2)
4903(2)
4206(2)
4043(1)
2500
794(1)
−273(3)
−284(3)
−3(3)
−584(3)
−480(3)
−1000(3)
−1650(3)
−1764(3)
−1245(3)
877(3)
1209(3)
1799(3)
2087(3)
1764(3)
1157(3)
−746(3)
−1315(3)
1772(3)
1653(3)
2068(3)
2254(3)
1318(1)
1739(1)
1911(1)
2432(1)
2773(1)
2598(1)
2075(1)
1370(1)
1122(1)
975(1)
1060(1)
1308(1)
1477(1)
0
412(2)
247(2)
68(1)
108(1)
140(1)
146(1)
140(1)
106(1)
87(1)
113(1)
142(1)
151(1)
142(1)
110(1)
83(1)
213(2)
171(3)
186(2)
510(5)
143(2)
519(7)
281(2)
1004(2)
1207(3)
2184(3)
2972(3)
2787(2)
1803(2)
4706(4)
4755(5)
4358(4)
−104(18)
898(4)
1268(3)
1796(3)
5000
5407(4)
5615(6)
5000
4321(2)
4712(2)
520(7)

S.-M. Kuang et al. / Journal of Organometallic Chemistry 558 (1998) 131–138
135
Table 6
centers are bridged by two Ph2Ppypz ligands and an
The crystal structures were determined by the direct
method, which yielded the positions of all non-hydro-
gen atoms. Hydrogen atoms were all generated geomet-
Atomic coordinates of complex 5 (×105 for Cu; ×104 for other
4
˚
atoms) and equivalent isotropic displacement coefficients (A×10 for
3
˚
Cu; A×10 for other atoms)
Atoms
x
y
z
Ueq
˚
rically (C–H bond lengths fixed at 0.96 A), assigned
appropriate isotropic thermal parameters and allowed
to ride on their parent carbon atoms. All the H atoms
were held stationary and included in the structure fac-
tor calculation in the final stage of full-matrix least-
squares refinement.
Computation was performed on a IBM-compatible
486 PC with the SHELTX/PC program package [8].
Information concerning X-ray data collection and
structure refinement of all compounds is summarized in
Table 1. Selected bond distances and angles are given in
Table 2. The final atomic parameters are given in
Tables 3–6, respectively.
Cu(1)
Cu(2)
P(1)
P(2)
Cl(1)
O(1)
O(2)
O(3)
O(4)
N(1)
N(2)
N(3)
N(4)
N(5)
N(6)
N(7)
N(8)
C(1)
C(2)
C(3)
C(4)
C(5)
C(6)
C(7)
C(8)
C(9)
C(10)
C(11)
C(12)
C(13)
C(14)
C(15)
C(16)
C(17)
C(18)
C(19)
C(20)
C(21)
C(22)
C(23)
C(24)
C(25)
C(26)
C(27)
C(28)
C(29)
C(30)
C(31)
C(32)
C(33)
C(34)
C(35)
C(36)
C(37)
C(38)
C(39)
C(40)
C(41)
C(42)
C(43)
18789(3)
18007(3)
2946(1)
1722(1)
388(1)
164(3)
1084(3)
47(5)
275(11)
1634(3)
1380(2)
1472(2)
1897(3)
2506(2)
2812(2)
1111(2)
1094(3)
1693(4)
1491(4)
1292(4)
1241(2)
862(3)
31588(6)
29018(7)
2570(1)
5187(1)
9074(2)
9435(10)
8769(11)
7993(14)
10137(20)
3568(5)
4870(5)
5194(4)
2064(6)
1388(4)
2029(4)
1937(5)
1808(5)
3040(8)
4013(8)
5158(8)
5702(5)
6909(6)
7672(6)
7189(6)
5952(5)
6192(5)
7194(8)
7902(9)
7608(9)
6579(13)
5885(11)
5897(6)
7183(7)
7620(8)
6853(7)
5576(8)
5108(7)
1704(8)
811(8)
34963(6)
22238(6)
3413(1)
2290(1)
5395(1)
5961(3)
5340(4)
5195(7)
5069(7)
4365(2)
4440(2)
3449(2)
1400(2)
1320(2)
2260(2)
3210(2)
2644(2)
4896(3)
5317(3)
5018(2)
3949(2)
3998(3)
3502(3)
2970(3)
2957(2)
2224(2)
2595(3)
2516(4)
2040(4)
1663(4)
1741(4)
1732(2)
1452(3)
1027(3)
869(3)
567(2)
578(2)
52(1)
54(1)
81(1)
154(2)
160(2)
293(3)
363(3)
73(1)
60(1)
54(1)
72(2)
62(1)
54(1)
64(1)
69(1)
89(2)
93(2)
86(2)
55(1)
68(2)
75(2)
70(2)
55(1)
61(1)
91(2)
100(2)
99(2)
131(2)
119(2)
60(1)
82(2)
88(2)
84(2)
92(2)
77(2)
83(2)
88(2)
72(2)
55(1)
72(2)
77(2)
68(2)
53(1)
54(1)
64(1)
73(2)
80(2)
84(2)
74(2)
61(1)
85(2)
104(2)
103(2)
101(2)
80(2)1
71(2)
77(2)
71(2)
3. Results and discussion
Reaction of [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2 with
Na2Fe(CO)4 in tetrahydrofuran gave [Cu2(v-
Ph2Ppypz)2(MeCN)2](Fe(CO)4), 1, which involves an
exchange of anions (Scheme 1).
The reaction of a transition-metal carbonylate anion
with an appropriate transition-metal electrophile has
proved to be a successful synthetic route to the forma-
tion of metal–metal bonds and metal clusters [9]. We
intended to utilize this reaction to generate a Cu2Fe
cluster with metal–metal bonds, but instead obtained
744(3)
992(3)
1352(2)
2510(3)
2727(4)
3342(4)
3720(4)
3528(5)
2912(4)
1171(3)
1279(4)
814(4)
an
anion
substitution
product,
[Cu2(v-
Ph2Ppypz)2(MeCN)2](Fe(CO)4), which is the first exam-
ple of a binuclear copper(I) complex with an iron
carbonylate anion. We attribute this result to the bulk-
iness of the Fe(CO)24− species which prevents the for-
mation of the Cu2Fe cluster.
284(4)
186(4)
625(3)
1120(3)
1555(3)
941(3)
575(3)
829(2)
1519(3)
1884(4)
2501(3)
3025(3)
3698(3)
4179(3)
3966(3)
3282(2)
3085(2)
3727(3)
3793(3)
3233(4)
2598(4)
2531(3)
3595(3)
3722(4)
4180(4)
4525(4)
4400(4)
3935(3)
538(3)
The structure of 1 is depicted in Fig. 1. The two
highly distorted tetrahedral copper(I) centers are
bridged by two Ph2Ppypz ligands. The geometry at the
Fe center is slightly distorted tetrahedral with bond
angles ranging from 105.8(1) to 116.1(1)°. Compared to
[Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2 in which the
Cu· · ·Cu distances of two independent cations are
638(6)
1562(5)
1308(7)
1515(8)
1928(7)
2168(5)
898(5)
1746(2)
1600(2)
2016(3)
2569(2)
2683(2)
3782(2)
3963(2)
4213(3)
4306(3)
4139(3)
3872(3)
3716(2)
4 313(3)
4556(4)
4211(4)
3625(4)
3380(3)
3437(3)
2989(3)
2493(3)
403(6)
˚
3.625(1) and 3.587(1) A [2], the Cu· · ·Cu separation in
−877(6)
−1713(7)
−1243(7)
56(6)
3712(6)
3707(7)
4627(9)
5554(8)
5579(8)
4685(7)
1423(6)
928(7)
˚
1 is significantly shorter (3.224(1) A), but no interaction
between copper centers and anions exists in both cases.
Treatment
of
a
solution
of
[Cu2(v-
Ph2Ppypz)2(MeCN)2](ClO4)2 in MeCN at r.t. with an
equimolar amount of LiCl or KI gives a solution from
which binuclear cationic complexes 2 or 3 can be
isolated in high yield. The complexes obtained are
stable in the solid state and have been characterized by
1H-NMR and 31P(1H)-NMR spectroscopy. In addition,
the structure of 3·Et2O has been determined by X-ray
crystallography.a
139(3)
512(3)
1164(7)

136
S.-M. Kuang et al. / Journal of Organometallic Chemistry 558 (1998) 131–138
‘bite angles’ of 77.8(1)° for Cu(1) and 79.3(1)° for Cu(2)
for the bidentate pyridylpyrazole fragments are as ex-
pected for a relatively rigid bidentate diamine ligand,
and the values are very similar to the that (78.9(3)°)
found in [Cu3L2(MeCN)2](PF6) (L=2, 6-bis(5-
methylpyrazol-3-yl)pyridine) [11] and those (78.9(2) and
78.6(2)°) found in [Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
[2].
For binuclear copper complexes with a carboxylate
bridge, a large number of studies have been devoted to
copper(II) complexes, especially the tetracarboxylate-
bridged copper(II) dimers [12], but little has been done
about copper(I) complexes [13], which is due to the
relative instability of binuclear copper(I) systems.
Reaction
of
NaO2CMe
with
[Cu2(v-
Scheme 1.
Ph2Ppypz)2(MeCN)2](ClO4)2 in THF afforded [Cu2(v-
Ph2Ppypz)2(v-O2CMe)](ClO4), 4, and similar reaction of
Lipz (prepared in situ from LinBu and pyrazole) with
[Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2
Ph2Ppypz)2(v-pz)](ClO4), 5, in good yield.
The formation of these complexes have been confi-
rmed by IR-, 1H-NMR and 31P(1H)-NMR spec-
troscopy. For complex 4, the IR spectrum shows
w(O2CMe) at 1558.3 and 1461.5 cm−1, which are typical
values for carbonyl stretching in bridging acetate com-
plexes [14].
The structure of the cation [Cu2(v-Ph2Ppypz)2(v-I)]+
in 3·Et2O is depicted in Fig. 2. The two copper(I) iodine
bridge. The geometry at the copper centers is highly
distorted but, despite the N(6)–Cu(1)–P(1) and N(3)–
Cu(2)–P(2) angles of 131.5(1) and 137.2(1)°, is better
described as a distorted square pyramid with the iodo
ligand occupying an equatorial position, rather than a
gave
[Cu2(v-
˚
trigonal bipyramid. The Cu–Cu distance of 2.832(1) A
is slightly longer than 2.758(1)
˚
A
in [Cu2(v-
Fig. 3 shows a perspective drawing of the cation
[Cu2(v-Ph2Ppypz)2(v-O2CMe)]+ in 4·Et2O with atomic
numbering. The two copper(I) centers with distorted
square pyramidal geometry are bridged by two
Ph2Ppypz)2(v-Cl)](ClO4)·H2O [2]. The Cu–I–Cu angle
of 64.1(1)° is also smaller than 70.2(1)° in [Cu2(v-
Ph2Ppypz)2(v-Cl)](ClO4)·H2O. The Cu–N bond lengths
˚
of 2.154(1), 2.050(1)
A
for Cu(1) and 2.089(1),
˚
2.089(2)A for Cu(2) are typical for a copper(I) center
chelated by nitrogen heterocycles [10]. The N–Cu–N
Fig. 1. Perspective view (35% thermal ellipoids) of [Cu2(v-
Ph2Ppypz)2(MeCN)2](Fe(CO)4), 1.
Fig. 2. Perspective view (35% thermal ellipoids) of the [Cu2(v-
Ph2Ppypz)2(v-I)]+ cation in 3·Et2O.

S.-M. Kuang et al. / Journal of Organometallic Chemistry 558 (1998) 131–138
137
Fig. 4. Perspective view (35% thermal ellipoids) of the [Cu2(v-
Ph2Ppypz)2(v-pz)]+ cation in 5.
Fig. 3. Perspective view (35% thermal ellipoids) of the [Cu2(v-
Ph2Ppypz)2(v-O2CMe)]+ cation in 4·Et2O.
should ideally equal to 0°. In complex 5, the the
M–{N–N}–C dihedral angle is −170.5° for Cu(1)–
N(7)–N(8)–C(43) and 166.0° for Cu(2)–N(8)–N(7)–
C(41), indicating that the metal is not significantly
displaced from the pyrazole plane.
Ph2Ppypz ligands and a acetate bridge. The Cu–Cu
˚
distance of 2.924(2) A is longer than that of complex 3
˚
and 2.750(2) A in [Cu2(v-PhCO2)2(p-MeC6H4NC)2],
˚
but shorter than that (3.020(3) A) in [Cu2(v-PhCO2)2(p-
MeC6H4NC)3]·THF ([13]a). The Cu–O distances of
In summary, we have investigated the reaction of
[Cu2(v-Ph2Ppypz)2(MeCN)2](ClO4)2 with several kinds
of anions to give new binuclear copper(I) complexes
that exhibit different structures.
˚
˚
˚
2.020(4) A for Cu(1) and 2.023(5)A for Cu(2) A are
˚
longer than those (1.998(4), 1.969(5) A) in [Cu2(v-
PhCO2)2(p-MeC6H4NC)2], but shorter than those
˚
(2.061(6),
2.078(5)
A)
in
[Cu2(v-PhCO2)2(p-
MeC6H4NC)3]·THF ([13]a). The torsion angle O(1)–
Cu(1)–Cu(2)–O(2) of −11.2° deviates from the ideal
value of 0°, which is a consequence of the asymmetry of
the phosphine ligand.
Acknowledgements
This work is supported by Hong Kong Research
Grants Council Earmarked Grant Ref. No. CUHK
4179/97P and the National Natural Science Foundation
of China.
The structure of the cation [Cu2(v-Ph2Ppypz)2(v-
pz)]+ in 5 is depicted in Fig. 4. The molecular structure
is very similar to that in 4·Et2O except that the acetate
bridge is here replaced by a pyrazolate bridge. The
coordination geometry at each copper atom is also
highly distorted square pyramidal with the pyrazlote N
atom in an equatorial site. The Cu(1)–Cu(2) bond
References
[1] (a) F. Zippel, F. Ahlers, R. Werner, W. Haase, H. Nolting, B.
Krebs, Inorg. Chem. 35 (1996) 3409. (b) K.D. Karlin, J. Zubieta
(Eds.), Biological and Inorganic Copper Chemistry, Adenine
Press, Guiderland New York, 1986. (c) K.D. Karlin, Z. Tyekla´r,
Bioinorganic Chemistry of Copper; Chapman & Hall, New
York, London, 1993, pp 143–196.
[2] S.M. Kuang, Q.G. Wang, Z.Z. Zhang, T.C.W. Mak, J. Chem.
Soc. Dalton Trans., accepted.
[3] S.M. Kuang, Z.Z. Zhang, Q.G. Wang, T.C.W. Mak, J. Chem.
Soc. Dalton Trans. (in press).
˚
length of 2.930(2) A is similar to that of complex
˚
4·Et2O. The equatorial Cu–N distances of 2.007(2) A
(average) is markedly shorter than the axial Cu–N
˚
distances of 2.101(2) A (average). The M–{N–N}–C
dihedral angle has been used to quantify both tilting
and twisting distortions of the pyrazole ring [15]. This is
essentially a measure of the displacement of the metal
atom from the pyrazole plane and, hence, the effective
overlap of a metal orbital with the sp2 hybridized
nitrogen. As such, the M–{N–N}–C dihedral angle
[4] J.P. Collman, R.G. Finke, J.N. Cawse, J.I. Brauman, J. Am.
Chem. Soc. 99 (1977) 2515.

138
S.-M. Kuang et al. / Journal of Organometallic Chemistry 558 (1998) 131–138
[5] M.G. Simmons, C.L. Merrill, L.J. Wilson, L.A. Bottomley,
[10] M. Melnik, L. Macaskova, C.E. Holloway, Coord. Chem. Rev.
126 (1993) 71.
[11] A.T. Baker, D.C. Craig, G. Dong, Inorg. Chem. 35 (1996)
1091.
K.M. Kadish, J. Chem. Soc. Dalton Trans. (1980) 1827.
[6] (a) J. Tanner, K. Krause, Rigaku J. 11 (1994) 4; 7 (1990) 28.
(b) K.L. Krauss, G.N. Phillips, Jr., J. Appl. Cryst. 25 (1992)
146. (c) M. Sato, M. Yamamoto, K. Imada, Y. Katsube, N.
Tanaka, T. Higashi, J. Appl. Cryst. 25 (1992) 348.
[7] T. Higashi, ABSCOR-An Empirical Absorption Correction
Based on Fourier Coefficient Fitting, Rugaku Corporation,
Tokyo, 1995.
[12] G. Smith, E.J. O’Reilly. H.L. Carrell, C.J. Carrell, C.H.L.
Kennard, Polyhedron 15 (1996)1995 references therein.
[13] (a) A. Toth, C. Floriani, A. Chiesi-Villa, C. Guastini, Inorg.
Chem. 26 (1987) 236. (b) M. Pasquali, P. Leoni, C. Floriani,
A.G. Manfredotti, Inorg. Chem. 21 (1982) 4324. (c) P.F.
Rodesiler, E.L. Amma, J. Chem. Soc. Chem. Commun. (1974)
599.
[14] K. Nakamoto, Infrared and Raman Spectra of Inorganic and
Coordination Compounds, 4th ed., Wiley, New York, 1986, p.
233.
[8] SHELXL/PC V5.0 Reference Manual; Siemens Analytical X-
Ray Instruments, Inc. Madison, Wisconsin, 1995.
[9] (a) G. Doyle, K.A. Eriksen, D. Van Engen, J. Am. Chem. Soc.
107 (1985) 7914. (b) G. Doyle, K.A. Eriksen, D. Van Engen, J.
Am. Chem. Soc. 108 (1986) 445. (c) H. Deng, S.G. Shore,
Organometallics 10 (1991) 3486. (d) H. Deng, D.W. Knoeppel,
S.G. Shore, Organometallics 11 (1992) 3472. (e) R.D. Adams,
in: D.F. Shriver, H.D. Kaesz, R.D. Adams (Eds.), The Chem-
istry of Metal Cluster Complexes, VCH, New York, 1990, p.
129.
[15] (a) D.L. Reger, J.E. Collins, S.M. Myers, A.L. Rheingold,
L.M. Liable-Sands, Inorg. Chem. 35 (1996) 4904. (b) D.L.
Reger, J.E. Collins, R. Layland, R.D. Adams, Inorg. Chem. 35
(1996) 1372.
.