Polynuclear silver(I) complexes of triphenylphosphine and 2-aminopyrimidine: Synthesis, structural characterization and spectroscopic properties

Article abstract of DOI:10.1016/j.poly.2011.06.003

The reactions of triphenylphosphine (PPh₃) and 2-aminopyrimidine (AMP) ligand with Ag salts in the mixed solvent of methanol (MeOH) and dichloromethane (CH₂Cl₂) lead to the mono-, di-, and tetranuclear complexes, [Ag(PPh₃)(AMP)₂](BF₄) (1), [Ag₂(PPh₃)₄(AMP)₂(SO ₄)] (2), [Ag₄ (PPh₃)₄(AMP) ₂(NO₃)₄]_∞ (3) and [Ag ₄(PPh₃)₄(AMP)₂(Ac)₄] _∞ (Ac = CH₃COO) (4) and [Ag(PPh₃) ₂(HCOO)]·CH₂Cl₂ (5). Complexes 1 and 2 are of 1D infinite chain structure controlled by intermolecular hydrogen bonds of type R22(8). In complexes 3 and 4, the 1D infinite chains are formed through the bridging-chelating anions (nitrate for 3 and acetate for 4) and the N,N′-bridging ligand AMP. Five-coordinated modes of Ag(I) are observed in 3 and 4. In the synthesis reaction of complex 5, AMP only acts as catalyst rather than ligand. All the complexes are characterized by X-ray diffraction. Compounds 1-4 are also characterized by fluorescence and ¹H, ³¹P NMR spectroscopy.

Full text of DOI:10.1016/j.poly.2011.06.003

Polyhedron 30 (2011) 2253–2259
Contents lists available at ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Polynuclear silver(I) complexes of triphenylphosphine and 2-aminopyrimidine:
Synthesis, structural characterization and spectroscopic properties
a
a
b
Li-Na Cui a, Ke-Yi Hu a, Qiong-Hua Jin a, , Zhong-Feng Li , Jie-Qiang Wu , Cun-Lin Zhang
⇑
a Department of Chemistry, Capital Normal University, Beijing 100048, China
b Beijing Key Laboratory for Terahertz Spectroscopy and Imaging, Key Laboratory of Terahertz Optoelectronics, Ministry of Education, Department of Physics,
Capital Normal University, Beijing 100048, China
a r t i c l e i n f o
a b s t r a c t
Article history:
The reactions of triphenylphosphine (PPh3) and 2-aminopyrimidine (AMP) ligand with Ag salts in the
mixed solvent of methanol (MeOH) and dichloromethane (CH2Cl2) lead to the mono-, di-, and tetranu-
Received 15 April 2011
Accepted 6 June 2011
Available online 15 June 2011
clear complexes, [Ag(PPh3)(AMP)2](BF4) (1), [Ag2(PPh3)4(AMP)2(SO4)] (2), [Ag4 (PPh3)4(AMP)2(NO3)4]
1
(3) and [Ag4(PPh3)4(AMP)2(Ac)4] (Ac = CH3COO) (4) and [Ag(PPh3)2(HCOO)]ꢀCH2Cl2 (5). Complexes 1
1
and 2 are of 1D infinite chain structure controlled by intermolecular hydrogen bonds of type R22(8). In
complexes 3 and 4, the 1D infinite chains are formed through the bridging-chelating anions (nitrate
for 3 and acetate for 4) and the N,N0-bridging ligand AMP. Five-coordinated modes of Ag(I) are observed
in 3 and 4. In the synthesis reaction of complex 5, AMP only acts as catalyst rather than ligand. All the
complexes are characterized by X-ray diffraction. Compounds 1–4 are also characterized by fluorescence
and 1H, 31P NMR spectroscopy.
Keywords:
Silver(I) complexes
Crystal structures
Triphenylphosphine
2-Aminopyrimidine
Spectroscopic properties
Ó 2011 Elsevier Ltd. All rights reserved.
1. Introduction
AMP ligand is bridged to the metal centers through the two
pyrimidyl nitrogen atoms, while in the dinuclear complex
In recent years, an increasing interest has developed towards
the supramolecular compounds for their various attractive struc-
tures [1] and potential applications in homogeneous catalytic pro-
cesses [2]. Because of its coordination diversity and flexibility, the
d10 metal Ag(I) ion has been extensively used as the connecting
node in the construction of supramolecular structures. Further-
more, many topologically promising architectures containing
Ag(I) and bidentate nitrogen donors have been constructed [3].
2-Aminopyrimidine (AMP), with one hydrogen bond donor
atom and two hydrogen bond acceptor atoms, is particularly
attractive as a very simple self-complementary prototype for chain
formation. Coordinated to the Ag(I), the ligand AMP can act as a
monodentate ligand or as a bidentate ligand in polymer structures.
In [Ru(AMP)(NH3)5](PF6)2 [4] and Cu(AMP)(2,6-dapy)ꢀ3H2O (2,6-
dapy = pyridine-2,6-dicarboxylato) [5], AMP ligand acts as a mono-
dentate ligand, it is bounded to the metal via either the nitrogen
atom of the amino group or the pyrimidyl nitrogen atoms. In the
trans-Ni(SCN)2(AMP)2 [6], AMP ligand acts as a bidentate chelating
ligand, it is bounded to the metal through one amine nitrogen atom
and one pyrimidyl nitrogen atom. In the dinuclear complex,
Zn2(DPD)(AMP) (DPD = diporphyrindibenzofuran) [7], [Ag2Cl2
[Pt2(NO3)4(AMP)2] [9], the AMP ligand is bridged to the metal cen-
ter through one amino nitrogen atom and one pyrimidyl nitrogen
atom. There is a tridentate coordination mode of AMP found in
the complex [Ag2(AMP)2(SO4)] [3].
1
In addition to the nature of the metal atoms and the ligands,
counter anions also play important roles in determining the final
structure of the product. Some Ag(I)X (X = Cl, Br) complexes with
triphenylphosphine (PPh3) and AMP have been reported [8–10],
but there are few reports about Ag(I)X (X = BF4, oxy-anions) com-
plexes with PPh3 and AMP.
In this paper, we studied the influence of several counter anions
on the structures. Five new complexes [Ag(PPh3)(AMP)2](BF4) (1),
[Ag2(PPh3)4(AMP)2(SO4)] (2), [Ag4(NO3)4(PPh3)4(AMP)2]1 (3) [Ag4
(Ac)4(PPh3)4(AMP)2]1 (Ac = CH3COO) (4) and [Ag(PPh3)2(HCOO)]ꢀ
CH2Cl2 (5) have been isolated and characterized by single crystal
X-ray diffraction. Complexes 1 and 2 are of 1D infinite chain struc-
ture controlled by intermolecular hydrogen bonds of type R22(8)
[11]. In complexes 3 and 4, the 1D infinite chains are formed owing
to the bridging-chelating anions (nitrate for 3 and acetate for 4)
and the N,N0-bridging ligand AMP. We attempted to obtain the
Ag–AMP–PPh3 complex containing formate (HCOOꢁ), but unex-
pectedly complex 5 was generated, which maybe is due to the
influence of the counter anion HCOOꢁ. Herein, the reactions of
(PPh3)2(2-AMP)] [8a] and [Ag2Br2(PPh3)2(2-AMP)] [8b], the
1
1
AgX (X = BF4ꢁ, SO42ꢁ, NO3ꢁ, Acꢁ, HCOOꢁ, NO2 and ClO4ꢁ) with
ꢁ
⇑
Corresponding author.
E-mail address: jinqh@mail.cnu.edu.cn (Q.-H. Jin).
PPh3 and AMP are studied.
0277-5387/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2011.06.003

2254
L.-N. Cui et al. / Polyhedron 30 (2011) 2253–2259
(10 ml, v/v = 1/1) containing AgNO3 (0.0680 g, 0.4 mmol), stirring
2. Experimental
2.1. Materials and measurements
for 2 h and then filtrating. The filtrate was allowed to stand at room
temperature, the crystal was obtained by slow evaporation of the
colorless solvent, which was filtered off and washed with Et2O to
give complex 3 as a colorless crystal. Yield: 80%. Anal. Calc. for
All chemical reagents are commercially available and used
without furthermore treatment. FT-IR spectra (KBr pellets) were
measured on a Perkin–Elmer infrared spectrometer. C, H and N ele-
mental analysis were carried out on a Elementar Vario MICRO
CUBE (Germany) elemental analyzer. Room-temperature fluores-
cence spectra were measured on F-4500 FL Spectrophotometer.
1H NMR and 31P NMR were recorded at room temperature with a
Bruker DPX 600 spectrometer.
C
80H70Ag4N10O12P4: C, 50.08; H, 3.68; N, 7.29. Found: C, 50.35; H,
3.82; N, 7.33% IR (cmꢁ1, KBr pellets): 3405m, 1631m, 1570m,
1480m, 1421m, 1384s, 1291s, 1189w, 1097w, 1028w, 998w,
746s, 693s, 518m, 503m.
2.2.4. Synthesis of [Ag4(Ac)4(PPh3)4(AMP)2]1 (4)
Complex 4 has been prepared following a procedure similar to
that reported for 1 by adding PPh3 (0.1048 g, 0.4 mmol) and AMP
(0.0190 g, 0.2 mmol) into a mixture of CH2Cl2 and MeOH (10 ml,
v/v = 1/1) containing AgAc (0.0668 g, 0.4 mmol). Yield: 76%. Anal.
Calc. for C44H41Ag2N3O4P2: C, 55.43; H, 4.33; N, 4.41. Found: C,
55.29; H, 4.15; N, 4.44%. IR (cmꢁ1, KBr pellets): 3431s, 3054m,
1564s, 1480m, 1435s, 1386m, 1096s, 1208w, 998w, 797m, 746s,
695s, 653w, 518m, 503m.
2.2. Preparation of the complexes
2.2.1. Synthesis of [Ag(PPh3)(AMP)2](BF4) (1)
AgBF4 (0.1170 g, 0.6 mmol) was dissolved in the mixture of
CH2Cl2 and MeOH (10 ml, v/v = 1/1), adding PPh3 (0.1572 g,
0.6 mmol) and AMP (0.114 g, 1.2 mmol) into the reaction flask la-
ter. After stirring for 2 h and then filtrating, the filtrate was slow
evaporated at ambient temperature. Four days later, a colorless
block complex was obtained. Yield: 30%. Anal. Calc. for
2.2.5. Synthesis of [Ag(PPh3)2(HCOO)]ꢀCH2Cl2 (5)
Complex 5 has been prepared following a procedure similar to
that reported for 1 by adding PPh3 (0.0524 g, 0.2 mmol) and AMP
(0.0380 g, 0.4 mmol) into a mixture of CH2Cl2 and MeOH (10 ml,
v/v = 1/1) containing Ag(HCOO) (0.0306 g, 0.2 mmol). Yield: 63%.
Anal. Calc. for C38H33AgCl2O2P2: C, 59.82; H, 4.33. Found: C,
59.76; H, 4.29%. IR (cmꢁ1, KBr pellets): 3051w, 1962w, 1889w,
1851w, 1584w, 1572w, 1479s, 1434s, 1329w, 1308m, 1265m,
1229s, 1155m, 1096s, 1070w, 1026m, 997m, 973w, 834w, 744s,
725m, 694s, 618w, 513s, 503s, 437w.
C
26H25AgBF4N6P: C, 48.25; H, 3.89; N, 12.98. Found: C, 48.33; H,
3.73; N, 12.82%. IR (cmꢁ1, KBr pellets): 3317s, 3123m, 3122m,
1525m, 1485m, 1435s, 1415m, 1230w, 1104vs, 998s, 985s, 748s,
698s, 524m, 516m.
2.2.2. Synthesis of [Ag2(PPh3)4(AMP)2(SO4)] (2)
Complex 2 has been prepared following a procedure similar to
that for
1 by adding PPh3 (0.1572 g, 0.6 mmol) and AMP
(0.0285 g, 0.3 mmol) into the mixture of CH2Cl2 and MeOH
(10 ml, v/v = 1/1) of Ag2SO4 (0.0612 g, 0.3 mmol). Yield: 65%. Anal.
Calc. for C82H78Ag2N6O6P4S: C, 60.98; H, 4.87; N, 5.20. Found: C,
61.25; H, 5.01; N, 5.27%. IR (cmꢁ1, KBr pellets): 3426s, 3053,
1632w, 1479s, 1434s, 1309w, 1181w, 1091s, 1027m, 998m, 746s,
696s, 618w, 513s, 501s.
2.3. X-ray crystallographic study of complexes
Single crystals of the title complexes were mounted on a
Bruker Smart 1000 CCD diffractometer equipped with a graph-
ite-monochromated Mo Ka (k = 0.71073 Å) radiation at 293(2) K.
Semi-empirical absorption corrections were applied using SABABS
program. All the structures were solved by direct methods using
SHELXS program of the SHELXTL-97 [12] package and refined with
SHELXL-97 [12]. Metal atom centers were located from the E-maps
2.2.3. Synthesis of [Ag4(NO3)4(PPh3)4(AMP)2]1 (3)
The PPh3 (0.1048 g, 0.4 mmol) and AMP (0.0190 g, 0.2 mmol)
was added at room temperature to a mixture of CH2Cl2 and MeOH
Table 1
Crystal data for complexes 1–5.
Compound
1
2
3
4
5
Formula
C
26H25AgBF4N6P
C82H78Ag2N6O6P4S
1615.18
monoclinic
C2/c
17.124(2)
21.649(2)
21.770(2)
90.00
108.366(2)
90.00
7659.5(13)
4
C80H70Ag4N10O12P4
1918.82
C44H41Ag2N3O4P2
953.48
C38H33AgCl2O2P2
762.35
Formula weight
Crystal system
Space group
a (Å)
b (Å)
c (Å)
647.17
orthorhombic
Pbca
triclinic
triclinic
triclinic
ꢀ
ꢀ
ꢀ
P1
P1
P1
18.600(2)
15.759(2)
19.368(2)
90.00
90.00
90.00
5677.3(10)
8
1.514
11.397(8)
12.186(9)
15.077(1)
93.845(4)
101.617(4)
99.259(4)
2013.5(2)
1
9.681(2)
15.033(2)
16.120(2)
66.383(1)
75.824(1)
82.612(2)
2082.8(5)
2
10.866(1)
13.106(1)
14.172(2)
105.169(3)
105.500(2)
103.150(1)
1778.5(3)
2
a
(°)
b (°)
(°)
c
Volume (Å3)
Z
Dcalc (g/cm3)
1.401
0.679
1.621
1.104
1.52
1.062
1.424
0.839
l
(mmꢁ1
)
0.819
F(0 0 0)
Crystal size (mm3)
Range (°)
Reflections collected
Reflections unique
Rint
2608
3320
978
964
776
0.50 ꢂ 0.48 ꢂ 0.45
1.99–25.01
27739
4955
0.0454
0.21 ꢂ 0.19 ꢂ 0.12
1.57–25.01
19280
6755
0.0726
0.28 ꢂ 0.25 ꢂ 0.21
2.06–27.96
21752
9280
0.0231
0.40 ꢂ 0.19 ꢂ 0.10
1.61–25.01
10494
7108
0.0450
0.35 ꢂ 0.30 ꢂ 0.23
2.64–25.02
9259
6173
0.0184
H
Parameters
381
1.188
0.05, 0.1692
0.750, ꢁ0.457
457
1.050
0.0576, 0.1330
0.748, ꢁ0.814
496
0.981
0.0364, 0.0793
0.434, ꢁ0.301
496
0.943
0.0828, 0.2098
3.897, ꢁ1.374
406
1.052
0.0369, 0.0805
0.538, ꢁ0.584
Goodness-of-fit on F2
R1 and wR2
Maximum, minimum peaks (e Åꢁ3
)

L.-N. Cui et al. / Polyhedron 30 (2011) 2253–2259
2255
Table 2
Selected bond lengths (Å) and angles (°) for complexes 1–5.
Complex 1
Ag(1)–N(1)
Ag(1)–N(4)
Ag(1)–P(1)
2.318(5)
2.268(5)
2.3680(2)
N(4)–Ag(1)–N(1)
N(4)–Ag(1)–P(1)
N(1)–Ag(1)–P(1)
93.0(2)
139.4(2)
127.4(1)
Complex 2
Ag(1)–O(1)
Ag(1)–P(2)
Ag(1)–P(1)
Ag(1)–N(1)
O(1)–Ag(1)–P(2)
2.355(5)
2.464(2)
2.467(2)
2.491(6)
106.1(1)
P(2)–Ag(1)–N(1)
P(1)–Ag(1)–N(1)
P(2)–Ag(1)–P(1)
O(1)–Ag(1)–N(1)
O(1)–Ag(1)–P(1)
104.7(2)
102.2(2)
129.9(6)
86.9(2)
116.8(2)
Complex 3
Ag(1)–N(1)
Ag(1)–P(1)
Ag(2)–N(2)
Ag(2)–P(2)
Ag(2)–O(4)
Ag(2)–O(6)
Ag(1)–O(1)
Ag(1)–O(1A)
2.311(2)
2.373(7)
2.293(2)
2.367(7)
2.412(2)
2.693(2)
2.420(2)
2.651(2)
Ag(2)–O(4A)
Ag(1)–O(2)
2.717(2)
2.723(3)
134.5(6)
121.7(6)
138.0(6)
122.5(6)
99.3(8)
102.4(8)
Scheme 1. Hydrogen bond of type R22(8).
N(1)–Ag(1)–P(1)
P(1)–Ag(1)–O(1)
N(2)–Ag(2)–P(2)
P(2)–Ag(2)–O(4)
N(2)–Ag(2)–O(4)
N(1)–Ag(1)–O(1)
are observed in 3 and 4, which are affected by the anions and
ligand AMP. We have studied similar reactions using the counter
anions formate, perchlorate and nitrite. The reactions of AgX
(X = HCOO, ClO4) with PPh3 in the presence of AMP could give
single crystals of complex 5, and [AgClO4(PPh3)3] (6) [13] or
[AgClO4(PPh3)3(MeOH)] (7) [14] depending on the time of crystal
growth. In these similar reactions, under the inducement of the
anion (formate and perchlorate), AMP acts as catalyst rather than
ligand, it leads to the generation of the complex 5, and 6 or 7.
Through the reaction of AgNO2 with PPh3 and AMP, we could
not get single crystal.
Complex 4
Ag(1)–N(1)
Ag(1)–P(1)
2.367(6)
2.383(2)
2.389(7)
2.679(7)
2.372(2)
2.379(7)
2.701(6)
2.399(6)
2.598(7)
2.698(6)
84.7(2)
P(1)–Ag(1)–O(1)
N(1)–Ag(1)–O(2)
P(1)–Ag(1)–O(2)
O(1)–Ag(1)–O(2)
P(2)–Ag(2)–O(3)
O(3)–Ag(2)–O(3A)
N(2)–Ag(2)–O(3)
P(2)–Ag(2)–O(4)
O(3)–Ag(2)–O(4)
Ag(2)–O(3)–Ag(2A)
N(1)–Ag(1)–P(1)
N(1)–Ag(1)–O(1)
129.8(2)
86.1(2)
116.2(2)
51.0(2)
134.3(2)
82.6(2)
90.2(2)
117.3(2)
51.1(2)
97.4(2)
125.7(2)
103.2(2)
Ag(1)–O(1)
Ag(1)–O(2)
Ag(2)–P(2)
Ag(2)–O(3)
Ag(2)–O(4)
Ag(2)–N(2)
Ag(2)–O(3A)
Ag(1)–O(1A)
N(2)–Ag(2)–O(4)
O(3)–Ag(2)–O(4A)
The choice of the solvent also has great influence on the exper-
imental product; we could not obtain the crystal of good quality if
only MeOH or CH2Cl2 was used as the solvent. The routine of syn-
thesis for complexes 1–5 is shown in Scheme 2.
131.7(2)
Complex 5
Ag(1)–P(2)
Ag(1)–P(1)
Ag(1)–O(1)
Ag(1)–O(2)
O(2)–Ag(1)–P(2)
2.423(9)
2.450(9)
2.482(3)
2.392(3)
2.372(2)
O(2)–Ag(1)–P(1)
P(2)–Ag(1)–O(1)
O(2)–Ag(1)–O(1)
P(1)–Ag(1)–O(1)
P(1)–Ag(1)–P(2)
110.0(8)
120.9(9)
49.6(1)
103.1(9)
128.042(3)
3.2. Single crystal X-ray studies
3.2.1. Complex [Ag(PPh3)(AMP)2](BF4) (1)
The molecular structure of complex 1 is illustrated in Fig. 1a.
The independent unit consists of one cation [Ag(PPh3)(AMP)2]+
and one free anion BF4ꢁ. The Ag atom is three-coordinated, sur-
rounded by one P atom of PPh3 and two N atoms of two AMP li-
gands. The AMP ligand coordinates to Ag atom through one
pyrimidyl N atom, with the two remaining N atoms uncoordinated.
The mean bond length of Ag–N (2.268(5) and 2.318(5) Å) is
2.293 Å. Packing is controlled by the intermolecular hydrogen
bond of type R22(8) formed by two N atoms and two N–H groups
from two AMP ligands. Two adjacent building blocks [Ag(PPh3)
(AMP)2]+ are connected by hydrogen bonds of type R22(8) to form
an infinite chain (Fig. 1b).
and other non-hydrogen atoms were located in successive differ-
ence Fourier syntheses. The final refinements were performed by
full matrix least-squares methods with anisotropic thermal
parameters for non-hydrogen atoms on F2. The hydrogen atoms
were generated geometrically and refined with displacement
parameters riding on the concerned atoms. Crystallographic data
and experimental details for structural analysis are summarized
in Table 1. The selected bond lengths, bond angles are listed in
Table 2.
3. Results and discussion
3.2.2. Complex [Ag2(PPh3)4(AMP)2(SO4)] (2)
The molecular structure of 2 is illustrated in Fig. 2a. The Ag(I)
metal center is coordinated by two P atoms of PPh3 ligands, one N
atom of the AMP ligand and one O atom of SO4 anion to form a
3.1. Synthesis of complexes 1–5
2ꢁ
Five complexes 1–5 were synthesized by the reactions of sil-
ver(I) salt with monodentate ligand PPh3 and nitrogen-containing
ligand AMP in the mixture solvent of dichloromethane and meth-
anol (Scheme 1). Complexes 1–5 are insoluble in diethyl ether
but soluble in the polar solvents such as ethanol, methanol, aceto-
nitrile, DMF and DMSO.
distorted tetrahedral geometry. The angles around Ag1 are in the
range from 86.9(2)° to 129.9(6)°, among them the maximum angle
P–Ag–P is caused by the steric interaction of the bulky PPh3 ligands.
2ꢁ
The anion SO4 bridges two Ag atoms through two O atoms.
The mean bond distances of Ag–O and Ag–N, Ag–P are 2.355 Å,
2.490 Å and 2.465 Å, respectively. The AMP ligand coordinates to
Ag atom through pyrimidyl one N atom, with the two remaining
N atoms uncoordinated. The units [Ag(PPh3)2(AMP)] form 1D infi-
The counter anion plays an important role in the formation of
the structure of the product. In 1–4, the anions BF4ꢁ, SO42ꢁ, NO3
ꢁ
and Acꢁ influence the coordination modes of the ligand AMP and
the hydrogen bond types between two AMP ligands, and thus
determine the final packing of the molecules. In 1 and 2, AMP
acts as mondentate ligand, the remaining N atoms and the unco-
ordinated two N–H groups form intermolecular hydrogen bonds
of type R22(8). In 3 and 4, AMP acts as N,N0-bridging ligand and
no hydrogen bond is formed. Five-coordinated modes of Ag(I)
nite chains via the O,O0-
l2-bridging sulfate and hydrogen bonds of
type R22(8) (Fig. 2b).
3.2.3. Complex [Ag4(NO3)4(PPh3)4(AMP)2]1 (3)
The molecular structure of complex 3 is given in Fig. 3a. Each Ag
atom adopts the five-coordinated mode – it is coordinated by three

2256
L.-N. Cui et al. / Polyhedron 30 (2011) 2253–2259
Scheme 2. The routine of synthesis for complexes 1–5.
(PPh3)] (2.591 Å) [17]. The sum of the internal angles of the quad-
rangles [–Ag1B–O1D–Ag1D–O1B–] and [–Ag2A–O4A–Ag2D–O4D–
] are both 360°, indicating that all the quadrangles formed by Ag
and l2-O atoms are coplanar.
In complex 3, the 1D infinite chain is formed owing to the bridg-
ing ability of NO3ꢁ and AMP (Fig. 3b). Each AMP ligand bridges two
Ag atoms in bidentate coordination mode through two N atoms,
and ꢁthe two Ag atoms are coordinated with tꢁhe inorganic anion
NO3 to form the 1D infinite chain. Here NO3 adopts bridging–
chelating bonding mode – it bridges two Ag atoms through one
l2-O atom and chelates the Ag atom through two O atoms.
3.2.4. Complex [Ag4(Ac)4(PPh3)4(AMP)2]1 (4)
The molecular structure of complex 4 is given in Fig. 4a. In 4, all
the Ag atoms are five-coordinated, surrounded by the P atom of
PPh3, one N atom of AMP and three O atoms from separate Acꢁ an-
ions. The mean bond lengths of Ag–O, Ag–N and Ag–P are 2.549,
2.383 and 2.378 Å, respectively, which are comparable with those
in complex 3. The angles around Ag atom vary from 82.6(2)° to
134.3(2)°, indicating that the five-coordinated geometry is really
distorted. From the equal angles \Ag2–O3–Ag2A and \Ag2–
O3A–Ag2A (97.4°), and the equal angles \O3A–Ag2–O3 and
\O3A–Ag2A–O3 (82.6°) we can see that the quadrangle Ag2O2
Fig. 1a. Perspective view of complex 1. All the hydrogen atoms are omitted for
clarity.
formed by two
l2-O atoms and two Ag atoms is approximately
parallelogram. Each Ag atom links the N atom of AMP ligand and
the O atoms of Acꢁ anion. The Acꢁ anion adopts the bridging–
chelating bonding mode – it bridges two Ag atoms through one
O atom and chelates the Ag atom through two O atoms to form
the linear structure as compound 3 (Fig. 4b).
O atoms from two NO3ꢁ anions, one N atom of AMP ligand and one
P atom of PPh3 ligand. The angles around Ag1 atoms lie from
48.7(4)° to 134.5(6)°, which approximate to the angles around
Ag2 atoms lying from 48.8(8)° to 138.0(6)°. The mean Ag–O
bond length is 2.508 Å, 0.036 Å longer than that observed in
[Ag4(dppe)3(NO3)4](2.472 Å) [15], but 0.147 Å shorter than that
found in [Ag(L0)(NO3)]1 (L0 = 2-amino-4,6-dimethylpyrimidine)
(2.655 Å) [3]. The mean bond length of Ag–N is 2.302 Å, which is
in agreement with that in [Ag2(AMP)2(SO4)]1 (2.373 Å) [3] and is
much more shorter than the sum of the van der Waals radii of
silver and nitrogen (1.55 + 1.70 = 3.25 Å) [16]. The mean bond
length of Ag–P is 2.371 Å, 0.220 Å shorter than that in [Ag(tsac)
3.2.5. Complex [Ag(PPh3)2(HCOO)]ꢀCH2Cl2 (5)
The crystal structure of 5 is illustrated in Fig. 5. It can be seen
from the figure that the title complex consists of one [Ag(PPh3)2
(HCOO)] neutral unit and one CH2Cl2 solvent molecule. The Ag(I)
metal center is coordinated by two P atoms of PPh3 ligands and
two O atoms of HCOOꢁ anion to form a distorted tetrahedral geom-
etry, which is similar to the reported complex [Ag(PPh3)2(HCOO)]
[18]. The angles around Ag1 (49.6(1)–128.0(3)°) in complex 5 vary
ꢁ
Fig. 1b. 1D chain hold by hydrogen bonds of complex 1. All BF4 and phenyl groups of PPh3 are omitted for clarity.

L.-N. Cui et al. / Polyhedron 30 (2011) 2253–2259
2257
in a wider range compared with the corresponding angles in
[Ag(PPh3)2(HCOO)] (55.1(4)–127.0(9)°). The mean bond distance
of Ag–O (2.437 Å) and the mean bond distance of Ag–P (2.436 Å)
are almost the same, and they are similar to the corresponding dis-
tances in complexes [Ag(PPh3)2(HCOO)] [18] and [AgNO2(PPh3)2]
[19]. The Ag–P distances (2.423(9) and 2.450(9) Å) are also similar
to those in complex [Ag(PPh3)2(ClO4)(CH3OH)] (2.431(1) and
2.428(1) Å) [14].
3.3. Luminescent properties
Figs. S1–S4 show the luminescent excitation and emission spec-
tra of complexes 1–4 in the solid state at 298 K. The ligand PPh3
exhibits fluorescence signal centered at 450 nm with an excitation
maximum at 435 nm. The emission peak of the ligand AMP can be
observed at 444 nm (kEx = 368 nm) [20]. Complexes 1–4 in the
Fig. 2a. Perspective view of complex 2. All the hydrogen atoms and phenyl groups
of PPh3 are omitted for clarity, symmetry code A = 1 ꢁ x, ꢁy, ꢁz.
Fig. 2b. 1D chain hold by hydrogen bonds of complex 2. All phenyl groups of PPh3 are omitted for clarity.
Fig. 3a. Perspective view of complex 3. All the hydrogen atoms and phenyl groups of PPh3 are omitted for clarity.
Fig. 3b. Perspective view of the linear one-dimensional chain of complex 3. All phenyl groups of PPh3 are omitted for clarity.

2258
L.-N. Cui et al. / Polyhedron 30 (2011) 2253–2259
Fig. 4a. Perspective view of complex 4. All the hydrogen atoms and phenyl groups of PPh3 are omitted for clarity, symmetry code A = 1 ꢁ x, 2 ꢁ y, 1 ꢁ z.
Fig. 4b. Perspective view of the linear one-dimensional chain of complex 4. All phenyl groups of PPh3 are omitted for clarity.
fer (XLCT) has been found in Cu(I)X–dppb complexes (X = coordi-
nated halide ion, dppb = bis(diphenylphosphino)benzene) [21], so
we presume that anion-to-ligand charge transfer exists in com-
plexes 2–4.
3.4. NMR spectra of complexes
The 1H NMR and 31P NMR spectra of complexes 1, 3 and 4 have
been measured at room temperature in DMSO-d6 solution, and the
1H NMR and 31P NMR spectra of complex 2 have been measured in
CDCl3. In 1H NMR spectra, all of the complexes show a signal at
8.1–8.3 ppm, which should be the signal of pyrimidine protons.
There is also a broad multiplet in the range 6.5–7.6 ppm, which
should be the signal of aromatic protons. These signals are all
shifted to the low-field region in comparison with the free ligands,
which may be resulted from the intermolecular hydrogen bonds of
type R22(8) in 1–2. Besides, a signal around 2.5 ppm should be the
signal of DMSO protons. The similarity of the resonance signals
of 1–4 in the solution state shows that the coordination modes
of AMP and anions should be similar.
Fig. 5. Perspective view of 5. All the hydrogen atoms are omitted for clarity.
solid state emit blue light. With excitation of laser at 419, 440, 442
and 440 nm, the emissions observed for 1–4 are 448, 468, 471 and
468 nm, respectively. The emission spectra of complexes 1–4 are
not assigned to the MLCT or LMCT, but to the ligand-centered
In 31P NMR spectrum of 1, the double resonance signal
(10.25 ppm and 12.71 ppm) shows that the 31P signal is split into
ꢁ
p
?
p⁄ charge transfer between the ligands PPh3 or AMP which
two peaks, which is maybe caused by free anion BF4 and coordi-
contain phenyl groups. In addition, the emission peaks of 2–4
(remarkably red-shifted) are not similar to that of complex 1,
which indicates that the metal ion is coordinated with the anion
nation-unsaturated Ag(I) cation. While in that of 2–4, all phospho-
rus atoms in each molecule are chemically equivalent because only
a single resonance signal is found (6.88 ppm for 2, 9.85 ppm for 3
and 12.03 ppm for 4). The similarity of resonance signals in
SO42ꢁ, NO3 or CH3COOꢁ. Since the halide-to-ligand charge trans-
ꢁ

L.-N. Cui et al. / Polyhedron 30 (2011) 2253–2259
2259
solution of 2–4 shows that the chemistry environment for the
phosphorus atom from PPh3 in 2–4 is similar.
These data can be obtained free of charge via http://www.ccdc.
cam.ac.uk/conts/retrieving.html, or from the Cambridge Crystallo-
graphic Data Centre, 12 Union Road, Cambridge CB2 1EZ, UK; fax:
(+44) 1223-336-033; or e-mail: deposit@ccdc.cam.ac.uk. Supple-
mentary data associated with this article can be found, in the
online version, at doi:10.1016/j.poly.2011.06.003.
From the 1H NMR spectra, 31P NMR spectra and crystal struc-
tures of 1–4, we can see that the structures of complexes 1–4 in so-
lid state depend on the counter anion, whileꢁthe structures of 2–4
in solution with counter anions SO42ꢁ, NO3 and Acꢁ should be
similar.
References
4. Conclusion
[1] (a) J.L. Atwood, J.E.D. Davies, J.M. Lehd, D.D. MacNicol, F. Vögtle,
Comprehensive Supramolecular Chemistry, Pergamon, Oxford, 1996;
(b) J.M. Lehn, Supramolecular Chemistry – Concepts and Perspectives, VCH,
Weinheim, 1995;
Five new Ag(I) complexes of PPh3 and nitrogen-containing
ligands AMP have been synthesized and characterized. The counter
anion plays an important role in the formation of the structure of
(c) D. Philp, J.F. Stoddart, Angew. Chem., Int. Ed. Engl. 35 (1996) 1155;
(d) O.M. Yaghi, H. Li, C. Davis, D. Richardson, T.L. Groy, Acc. Chem. Res. 31
(1998) 474;
2ꢁ
the product. Owing to the strong bridging ability of anions SO4
,
NO3ꢁ, CH3COOꢁ and ligand AMP in 2–4, and also owing to the
strong ability of AMP to form hydrogen bonds of type R22(8) in
1–2, the complexes 1–4 are of infinite chain structure. The anions
(nitrate in 3 and acetate in 4) act as the bridging-chelating ligands.
Five-coordinated modes of Ag(I) are observed in 3 and 4. In the
synthesis reaction of complex 5, AMP only acts as catalysis rather
than ligand. Complexes 1–4 exhibit intense luminescence at room
temperature. The 1H NMR and 31P NMR spectra show that thꢁe
structures of 2–4 in solution with counter anions SO42ꢁ, NO3
and Acꢁ should be similar.
(e) M. Fujita, Acc. Chem. Res. 32 (1999) 53.
[2] M. Sawamura, H. Hamashima, Y. Ito, J. Org. Chem. 55 (1990) 5935.
[3] Y.H. Wang, K.L. Chu, H.C. Chen, C.W. Yeh, Z.K. Chan, M.C. Suen, J.D. Chen, J.C.
Wang, Cryst. Eng. Commun. 8 (2006) 84.
[4] K.J. LaChance-Galang, I. Maldonado, M.L. Gallagher, W. Jian, A. Prock, J.
Chacklos, R.D. Galang, M.J. Clarke, Inorg. Chem. 40 (2001) 485.
[5] E. Altin, R. Kirchmaier, A. Lentz, Z. Kristallogr. 219 (2004) 35.
[6] P. Lumme, H. Elo, J. Janne, Inorg. Chim. Acta 92 (1984) 245.
[7] C.J. Chang, Z.H. Loh, Y. Deng, D.G. Nocera, Inorg. Chem. 42 (2003) 8262.
[8] (a) Q.H. Jin, X.L. Xin, X.Y. Ci, K.B. Yu, Acta Crystallogr., Sect. C 58 (2002) m174;
(b) Q.H. Jin, H.G. Zheng, X.L. Xin, X.Y. Ci, K.B. Yu, Z. Kristallogr. NCS 217 (2002)
341.
[9] A.I. Stetsenko, K.I. Yakovlen, A.L. Iais, Koord. Khim. 5 (1979) 1129.
[10] K.L. Tang, T.B. Xia, X.L. Jin, Y.Q. Jin, Beijing Daxue Xuebao, Ziran Kexueban 31
(1995) 695.
[11] Q.H. Jin, L.L. Zhou, L.J. Xu, Y.Y. Zhang, C.L. Zhang, X.M. Lu, Polyhedron 29 (2010)
317.
Acknowledgements
[12] G.M. Sheldrick, Acta Crystallogr., Sect. A 64 (2008) 112.
[13] L.N. Cui, K.Y. Hu, Q.H. Jin, C.L. Zhang, Acta Crystallogr., Sect. E 66 (2010) m871.
[14] L.N. Cui, K.Y. Hu, Q.H. Jin, C.L. Zhang, Acta Crystallogr., Sect. E 66 (2010) m969.
[15] M.S. Huang, P. Zhang, Y. Zhang, H.H. Yang, L.S. Zheng, Acta Phys.-Chim. Sin. 7
(1991) 694.
This work has been supported by National Keystone Basic
Research Program (973 Program) under grant Nos. 2007CB310408,
2006CB302901 and Funding Project for Academic Human
Resources Development in Institutions of Higher Learning Under
the Jurisdiction of Beijing Municipality. It is also supported by State
Key Laboratory of Functional Materials for Informatics, Shanghai
Institute of Microsystem and Information Technology, Chinese
Academy of Sciences.
[16] A. Bondi, J. Phys. Chem. 68 (1964) 441.
[17] M. Dennehy, O.V. Quinzani, M. Jennings, J. Mol. Struct. 84 (2007) 1110.
[18] L.S. Zheng, H.H. Yang, Q.E. Zhang, Chin. J. Struct. Chem. 10 (1991) 97.
[19] C. Augusto, Effendy, P. Maura, P. Claudio, S. Carlo, B.W. Skelton, A.H. White,
Inorg. Chem. 41 (2002) 6633.
[20] Q.H. Jin, J.J. Sun, J.Q. Wu, Y.C. Dai, C.L. Zhang, J. Chem. Cryst. 40 (2010) 310.
[21] A. Tsuboyama, K. Kuge, M. Furugori, S. Okada, M. Hoshino, K. Ueno, Inorg.
Chem. 46 (2007) 1992.
Appendix A. Supplementary data
CCDC 716493, 716491, 714576, 714583 and 820581 contain the
supplementary crystallographic data for complexes 1, 2, 3, 4 and 5.