Construction of heterobimetallic Cd(Hg)/Cu(Ag)/S(Se) complexes from homoleptic [Hg(EPh)2] molecules and [Cd(EPh)4] 2- anions (E = S, Se)

Article abstract of DOI:10.1016/j.poly.2011.11.046

Treatment of [Hg(EPh)₂] with 2 equivalents of [Cu(PPh ₃)₂Cl] gave the trinuclear Hg/Cu/S(Se) complexes [Hg(μ-EPh)₂{CuCl(PPh₃)₂}] (E = S 1, Se 2) in which the two copper centers are ligated by the [PhE]^- ligands of the [Hg(EPh)₂]. A similar reaction of [Hg(EPh)₂] with [Ag(PPh₃)₂Cl] gave rise to isolation of the dinuclear compounds [Hg(SePh)(μ-SePh)(μ-Cl)Ag(PPh₃)₂] (E = S 3, Se 4) in which the coordination geometry of the mercury atom is a slightly distorted T-shape. Reactions of the homoleptic tetrahedral species [Cd(EPh) ₄]^2- with 2 equivalents of [Cu(PPh₃) ₂NO₃] afforded the neutral linear trinuclear complexes [Cd(μ-EPh)₄{Cu(PPh₃)₂}₂] (E = S 5, Se 6) in which two [Cu(PPh₃)₂]⁺ fragments bind with the opposite edges of a tetrahedral [Cd(EPh)₄]^2- moiety via the sulfur or selenium atoms of the PhE^- ligands. A similar reaction of [Me₄N]₂[Cd(SPh)₄] with 2 equivalents of [Ag(PPh₃)₂NO₃] gave an analogous complex [Cd(μ-SPh)₄{Ag(PPh₃)₂}₂] (7), whereas the reaction of [Me₄N]₂[Cd(EPh)₄] with an equivalent amount of [Ag(PPh₃)₂NO₃] under similar conditions afforded the neutral heptanuclear complexes [Cd ₃(μ-EPh)₆(μ₃-EPh)₄(AgPPh ₃)₄] (E = S 8, Se 9) which comprise three [(AgPPh ₃)]⁺ fragments side-ligated and one [(AgPPh ₃)]⁺ fragment side-capped with the trinuclear cadmium-thio(seleno)phenolate [Cd₃(μ-EPh) ₉(μ₃-EPh)]^4- moieties via the sulfur atoms of thiophenolates in 8 and the selenium atoms of selenophenolates in 9. The nonlinear optical properties of two neutral heptanuclear complexes 8 and 9 have been examined by z-scan techniques with 7-ns pulses at 532 nm.

Full text of DOI:10.1016/j.poly.2011.11.046

Polyhedron 33 (2012) 185–193
Contents lists available at SciVerse ScienceDirect
Polyhedron
journal homepage: www.elsevier.com/locate/poly
Construction of heterobimetallic Cd(Hg)/Cu(Ag)/S(Se) complexes from
homoleptic [Hg(EPh)2] molecules and [Cd(EPh)4]2ꢀ anions (E = S, Se)
Chao Xu a,b, Jing-Jing Zhang a,b, Tai-Ke Duan b, Qun Chen a, Wa-Hung Leung c, Qian-Feng Zhang a,b,
⇑
a Department of Applied Chemistry, School of Petrochemical Engineering, Changzhou University, Jiangsu 213164, PR China
b Institute of Molecular Engineering and Applied Chemistry, Anhui University of Technology, Ma’anshan, Anhui 243002, PR China
c Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, PR China
a r t i c l e i n f o
a b s t r a c t
Article history:
Treatment of [Hg(EPh)2] with 2 equivalents of [Cu(PPh3)2Cl] gave the trinuclear Hg/Cu/S(Se) complexes
[Hg(
-EPh)2{CuCl(PPh3)2}] (E = S 1, Se 2) in which the two copper centers are ligated by the [PhE]ꢀ
ligands of the [Hg(EPh)2]. A similar reaction of [Hg(EPh)2] with [Ag(PPh3)2Cl] gave rise to isolation of
the dinuclear compounds [Hg(SePh)( -SePh)( -Cl)Ag(PPh3)2] (E = S 3, Se 4) in which the coordination
Received 3 September 2011
Accepted 16 November 2011
Available online 9 December 2011
l
l
l
geometry of the mercury atom is a slightly distorted T-shape. Reactions of the homoleptic tetrahedral
species [Cd(EPh)4]2ꢀ with 2 equivalents of [Cu(PPh3)2NO3] afforded the neutral linear trinuclear com-
Keywords:
Heterometallic complexes
Metalloligand
Mercury
Cadmium
Thiolate
plexes [Cd(l
-EPh)4{Cu(PPh3)2}2] (E = S 5, Se 6) in which two [Cu(PPh3)2]+ fragments bind with the oppo-
site edges of a tetrahedral [Cd(EPh)4]2ꢀ moiety via the sulfur or selenium atoms of the PhEꢀ ligands. A
similar reaction of [Me4N]2[Cd(SPh)4] with 2 equivalents of [Ag(PPh3)2NO3] gave an analogous complex
[Cd(l-SPh)4{Ag(PPh3)2}2] (7), whereas the reaction of [Me4N]2[Cd(EPh)4] with an equivalent amount of
[Ag(PPh3)2NO3] under similar conditions afforded the neutral heptanuclear complexes [Cd3(
l
-EPh)6
-EPh)9
Selenolate
Nonlinear optical properties
(l
3-EPh)4(AgPPh3)4] (E = S 8, Se 9) which comprise three [(AgPPh3)]+ fragments side-ligated and one
[(AgPPh3)]+ fragment side-capped with the trinuclear cadmium-thio(seleno)phenolate [Cd3(
l
(l
3-EPh)]4ꢀ moieties via the sulfur atoms of thiophenolates in 8 and the selenium atoms of selenophen-
olates in 9. The nonlinear optical properties of two neutral heptanuclear complexes 8 and 9 have been
examined by z-scan techniques with 7-ns pulses at 532 nm.
Ó 2011 Elsevier Ltd. All rights reserved.
1. Introduction
the number of coinage-metal atoms bound to the tetrahedral
[MQ4]2ꢀ moiety with six MQ2 edges [9]. The successful isolation of
The study of transition-metal chalcogenolate chemistry has been
actively investigated in two decades [1], motivated primarily by the
bonding diversity [2], reactivity [3], and potential use as precursors
for the binary and ternary metal-chalcogenide materials [4].
Remarkably, the search for the new metal-chalcogen containing
building blocks is of current interest because of their capability to
manipulate single-source precursors for nano-crystalline photovol-
taic materials [5], as well as other materials and biological
applications [6]. In contrast to well-documented binary metal-
chalcogenides, there are relatively few reports on the preparation
of ternary metal-chalcogenides which have found widespread appli-
cation in optical and electronic devices [7]. Recently, reactions of tet-
rathio- and tetraseleno-metalates [MQ4]2ꢀ (M = Mo, W; Q = S, Se)
with coinage-metal ions resulted in the syntheses and structures
of many types of hetero-transition-metal clusters [8]. The variation
of structural types of these heterometal clusters mainly depends on
those clusters offers an opportunity to study the structure–property
relationships of inorganic cluster materials [10]. The indium- and
gallium-tetrathiolates [M(SR)4]ꢀ (M = In, Ga) obtained by treatment
of metal trichloride with sodium alkylthiolate react with copper- or
silver-phosphine species to produce ternary Cu(Ag)/In(Ga)/S com-
plexes which can be effective single-source precursors to nanocrys-
talline photovoltaic materials [5]. The electron-rich sulfur affinity
and their less steric hindrances probably provide the ability of
homoleptic [M(SR)4]ꢀ (M = In, Ga) anions as metalloligands towards
coinage-metals [5a,11]. Similarly, the active sulfur atoms of the neu-
tral spirocyclic [Sn(edt)2] (edt = ethane-1,2-dithiolate) are capable
of binding copper atoms to form heterometallic Cu/Sn/S complexes
such as linear trinuclear [(Ph3P)Cu]2Sn(edt)2 and the bottle-shaped
heptanuclear [Cu4Sn3(edt)6(l3-O)(PPh3)4](ClO4)2 with strong
luminescent properties [12]. Brennan and co-workers reported the
syntheses and structural characterization of the series of heterome-
tallic chalcogenolate complexes having the general formula
MM0(EPh)x(L)y [M = Zn, Cd, Hg; M0 = divalent (x = 4) or trivalent
(x = 5) rare earth; E = S, Se, Te; L = THF, pyridine] [13]. These hetero-
metallic Ln-group 12 chalcogenolates have a broad range of poten-
tial applications in the rapidly developing field of rare earth-doped
⇑
Corresponding author at: Department of Applied Chemistry, School of Petro-
chemical Engineering, Changzhou University, Jiangsu 213164, PR China. Tel./fax:
+86 555 2312041.
E-mail address: zhangqf@ahut.edu.cn (Q.-F. Zhang).
0277-5387/$ - see front matter Ó 2011 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2011.11.046

186
C. Xu et al. / Polyhedron 33 (2012) 185–193
semiconductor technology [14]. Corrigan and coworkers synthe-
sized a series of ternary Zn/Cd(Hg)/E (E = S, Se, Te) clusters by con-
trolling modulation of crystalline size and reduction of
polydispersity, since silyl reagents, like Se(SiMe3)2 and RSeSiMe3,
finding extensive use as a source of Se2ꢀ and RSeꢀ in the synthesis
of metal–selenide nanoclusters and colloids [15]. By way of a similar
synthetic route, Fenske and co-workers have successfully isolated
series of ternary chalcogenide high-nuclear clusters containing
groups 11 and 13 metals [16]. Thus, the development of new ap-
proaches to synthesize ternary heterometallic chalcogenides as pre-
cursors to the according nanoparticles is still an attractive pursuit.
It is well known that synthetic routes for ternary heterometallic
clusters used in the present days are not many, which stimulates
many synthetic chemists to find useful metal-complexes as syn-
thons to construct the ternary clusters. One of the notable examples
is the use of [Hg(EPh)2] (E = Se, Te) as a precursor for the preparation
of nanoclusters using redistribution reactions [17]. A considerable
degree of variation in mercury coordination geometries transferred
from two to three or four coordination, accordingly, the resulting
homoleptic [Hg(ER)n]mꢀ (n = 2, 3, 4; m = 0, 1, 2) species lead to vari-
able compositions and structures of the clusters [18]. Lang and co-
workers have successfullyisolated a series of heterometallic clusters
elemental analyses were carried out using a Perkin–Elmer 2400
CHN analyzer. Electronic absorption spectra were obtained on a
Shimadzu UV-3000 spectrophotometer. Infrared spectra were
recorded on a Digilab FTS-40 spectrophotometer with use of
pressed KBr pellets. Positive FAB mass spectra were recorded on
a Finnigan TSQ 7000 spectrometer. NMR spectra were recorded
on
121.5 MHz for 1H and 31P, respectively, and chemical shift (d,
ppm) were reported with reference to SiMe4 (1H) and H3PO4 31P).
a Bruker ALX 300 spectrometer operating at 300 and
(
2.2. Preparation of [Hg(
l
-SPh)2{CuCl(PPh3)2}]ꢁ2dmf (1ꢁ2dmf)
To a solution of [Hg(SPh)2] (105 mg, 0.25 mmol) in MeCN
(10 mL) was added [Cu(PPh3)2Cl] (312 mg, 0.50 mmol) in CH2Cl2
(10 mL) with stirring. The mixture was stirred at room temperature
for 45 min. Fine white solids were gradually observed. The precip-
itates were collected by suction filtration and washed twice with
10 mL portions of diethyl ether. White air-stable solids were further
recrystallized from DMF/MeCN to give colorless block crystals of
1ꢁ2dmf in three days. Yield: 287 mg (64%). Anal. Calc. for C84H70
Cl2P4S2HgCu2ꢁ2(C3H7NO): C, 59.6; H, 4.67; N, 1.55. Found: C, 59.5;
H, 4.62; N, 1.53%. UV–Vis (DMF, kmax/nm, 10ꢀ3
e
/Mꢀ1 cmꢀ1): 263
(C–H) 3055 (m), (C@O)
(Cu–P) 448 (w) and 439
[Hg6Ag4(TePh)16], [Hg6Ag4Te(TePh)14 n
]
and [Hg8Te(TePh)12Cl4]Q
(9.6), 346 (1.4). IR (KBr disc, cmꢀ1):
1667 (s), (P–C) 1081 (s), (C–S) 691 (s), m
m
m
[Q = {Co(DMF)6}2+, {Ni(DMF)6}2+], which were obtained by the reac-
tion of [Hg(TePh)2] with M0 salts (M0 = AgI, CoII, NiII) and stabilized by
different phosphines (PPh3 or PMe2Ph), in dimethylformamide
(DMF) [17,19]. The analogous [Cd(ER)2] (E = S, Se; R = alkyl or aryl)
can act as single-source compounds to yield Cd–E clusters via a ‘bot-
tom up’ strategy, however, the propensity of the solid state struc-
tures of those compounds shows to possess a three-dimensional
nonmolecular polyadamantoid or superdiamondoid network. In
fact, crystalline products [Cd(EPh)2] (E = S, Se) are inorganic poly-
mers consisting of [Cd4(EPh)6] adamantane-like cages [20], which
was further supported by formation of tetranuclear adamanta-
noid-type clusters [Cd4(SePh)x(PPh3)X]n (X = Cl, Br; x = 6, 7) ob-
tained from the reaction of [Cd(SePh)2] with CdX2 in the presence
of PPh3 [21]. In this connection, we are realizing the coordination
behavior of mononuclear cadmium(II) complexes [Cd(EPh)4]2ꢀ
(E = S, Se) that contain the distorted tetrahedral CdE4 chromophore,
which may be reasonably speculated to coordinate to coinage-met-
als via sulfur atoms of thiophenolates and selenium atoms of seleno-
phenolates. Thus, the ability of homoleptic [Cd(EPh)4]2ꢀ anions as
metallo-ligands towards coinage-metals is due to the electron-rich
sulfur and selenium affinity and the deviations of the E–Cd–E angles
from tetrahedral symmetry [22]. In order to prepare heterobimetal-
lic Cd(Hg)/Cu(Ag)/S(Se) complexes, we selected homoleptically neu-
tral [Hg(EPh)2] and anionic [Cd(EPh)4]2ꢀ (E = S, Se) complexes as
precursors to coordinate with the [M(PPh3)2Q] (M = Cu, Ag;
Q = Clꢀ, NO3ꢀ) species which then gave a series of new neutral bime-
tallic complexes. Their structural characterizations and spectro-
scopic properties are described and the nonlinear optical
properties (NLO) of two novel heptanuclear Cd/Ag/S(Se) complexes
were also investigated in this paper.
m
m
(w). 1H NMR (DMSO-d6, ppm): d 2.98 (s, 6H, Me2NCHO), d 2.86 (s,
6H, Me2NCHO), 7.15–7.54 (m, 70H, Ph), 8.03 (s, 2H, CHO). 31P
NMR (DMSO-d6, ppm): d ꢀ3.78 (s). MS (FAB): m/z 1666 (M+),
1631 (M+ꢀCl), 1596 (M+ꢀ2Cl).
2.3. Preparation of [Hg(
l
-SePh)2{CuCl(PPh3)2}2]ꢁ2dmf (2ꢁ2dmf)
The method was similar to that used for 1ꢁ2dmf, employing
[Hg(SePh)2] (128 mg, 0.25 mmol) in instead of [Hg(SPh)2]. Color-
less blocks were obtained. Yield: 243 mg (51%). Anal. Calc. for C84
H70Cl2P4Se2HgCu2ꢁ2(C3H7NO): C, 56.7; H, 4.44; N, 1.47. Found: C,
56.2; H, 4.41; N, 1.42%. UV–Vis (DMF, kmax/nm, 10ꢀ3
e
/Mꢀ1 cmꢀ1):
263 (9.6), 359 (1.4), 368 (sh). IR (KBr disc, cmꢀ1):
(C–H) 3053 (m),
(C@O) 1665 (s), (P–C) 1081 (s), (C–Se) 663 (s), m(Cu–P) 445 (w)
m
m
m
m
and 432 (w). 1H NMR (DMSO-d6, ppm): d 2.96 (s, 6H, Me2NCHO),
2.84 (s, 6H, Me2NCHO), 7.13–7.57 (m, 70H, Ph), 8.01 (s, 2H, CHO).
31P NMR (DMSO-d6, ppm): d ꢀ3.21 (s). MS (FAB): m/z 1760 (M+),
1725 (M+ꢀCl), 1690 (M+ꢀ2Cl).
2.4. Preparation of [Hg(SPh)(
l
-SPh)(
l
-Cl)Ag(PPh3)2]ꢁdmf (3ꢁdmf)
The method was similar to that used for 1ꢁ2dmf, employing
[Ag(PPh3)2Cl] (334 mg, 0.50 mmol) in instead of [Cu(PPh3)2Cl]. Col-
orless blocks were obtained. Yield: 169 mg (58%). Anal. Calc. for
C
48H40ClP2S2HgAgꢁ(C3H7NO): C, 52.8; H, 4.08; N, 1.21. Found: C,
52.5; H, 4.07; N, 1.19%. UV–Vis (DMF, kmax/nm, 10ꢀ3 /Mꢀ1 cmꢀ1):
(C–H) 3051 (m), (C@O)
(Ag–P) 420 (w) and 412
e
267 (10.2), 349 (1.6). IR (KBr disc, cmꢀ1):
1663 (s), (P–C) 1084 (s), (C–S) 692 (s),
m
m
m
m
m
(w). 1H NMR (DMSO-d6, ppm): d 2.99 (s, 3H, Me2NCHO), 2.85 (s, 3H,
Me2NCHO), 7.17–7.62 (m, 35H, Ph), 8.02 (s, 1H, CHO). 31P NMR
(DMSO-d6, ppm): d ꢀ3.94 (s). MS (FAB): m/z 1086 (M+), 1051
(M+ꢀCl).
2. Experimental
2.1. Materials and measurements
2.5. Preparation of [Hg(SePh)(
l
-SePh)(
l
-Cl)Ag(PPh3)2]ꢁdmf (4ꢁdmf)
All syntheses were performed in oven-dried glassware under a
purified nitrogen atmosphere using standard Schlenk techniques.
The solvents were purified by conventional methods and degassed
prior to use. [Hg(SPh)2] [23], [Hg(SePh)2] [18c], [Me4N]2[Cd(SPh)4]
[22], [Me4N]2[Cd(SePh)4] [22], [Cu(PPh3)2Cl] [24], [Ag(PPh3)2Cl]
[24], [Cu(PPh3)2NO3] [25], and [Ag(PPh3)2NO3] [25] were prepared
by the literature methods. PhSH, PhSeSePh, and PPh3 were pur-
chased from Alfa Aesar and used without further purification. All
The method was similar to that used for 3ꢁdmf, employing
[Hg(SePh)2] (128 mg, 0.25 mmol) in instead of [Hg(SPh)2]. Color-
less blocks were obtained. Yield: 169 mg (58%). Anal. Calc. for
C
48H40ClP2Se2HgAgꢁ(C3H7NO): C, 48.9; H, 3.78; N, 1.12. Found: C,
48.4; H, 3.73; N, 1.11%. UV–Vis (DMF, kmax/nm, 10ꢀ3 /Mꢀ1 cmꢀ1):
269 (10.7), 353 (1.8). IR (KBr disc, cmꢀ1):
(C–H) 3054 (m), (C@O)
1665 (s), (P–C) 1081 (s), (C–Se) 665 (s), (Ag–P) 422 (w) and 411
e
m
m
m
m
m

C. Xu et al. / Polyhedron 33 (2012) 185–193
187
(w). 1H NMR (DMSO-d6, ppm): d 2.98 (s, 3H, Me2NCHO), 2.88 (s, 3H,
2.10. Preparation of [Cd3(
(9ꢁ0.5dmf)
l
-SePh)6(
l
3-SePh)4(AgPPh3)4]ꢁ0.5dmf
Me2NCHO), 7.15–7.67 (m, 35H, Ph), 8.05 (s, 1H, CHO). 31P NMR
(DMSO-d6, ppm): d ꢀ3.48 (s). MS (FAB): m/z 1080 (M+), 1145
(M+ꢀCl).
The method was similar to that used for 8, employing
[Me4N]2[Cd(SePh)4] (354 mg, 0.40 mmol) in instead of [Me4N]2
[Cd(SPh)4]. Colorless blocks were obtained. Yield: 178 mg (49%).
Anal. Calc. for C132H110P4Se10Cd3Ag4ꢁ0.5(C3H7NO): C, 47.0; H,
3.35; N, 0.20. Found: C, 46.4; H, 3.31; N, 0.18%. UV–Vis (DMF,
2.6. Preparation of [Cd(l-SPh)4{Cu(PPh3)2}2] (5)
To a solution of [Me4N]2[Cd(SPh)4] (140 mg, 0.20 mmol) in
MeCN (10 mL) was added [Cu(PPh3)2NO3] (260 mg, 0.40 mmol) in
CH2Cl2 (10 mL) with stirring. The mixture was stirred at room tem-
perature for 30 min. Fine white solids were observed. The precipi-
tates were collected by suction filtration and washed twice with
10 mL portions of diethyl ether. White air-stable solids were ob-
tained and further recrystallized from DMF/MeCN to give colorless
block crystals of 5 after 3 days. Yield: 225 mg (65%). Anal. Calc. for
kmax/nm, 10ꢀ3
(KBr disc, cmꢀ1):
(s), (C–Se) 664 (s),
e
/Mꢀ1 cmꢀ1): 261 (10.1), 352 (2.5), 368 (sh). IR
(C–H) 3053 (m), (C@O) 1666 (s), (P–C) 1084
(Ag–P) 421 (w) and 413 (w). 1H NMR
m
m
m
m
m
(DMSO-d6, ppm): d 2.98 (s, 1.5H, Me2NCHO), 7.11–7.57 (m, 110H,
Ph), 8.03 (s, 0.5H, CHO). 31P NMR (DMSO-d6, ppm): d ꢀ4.42 (s).
MS (FAB): m/z 3378 (M+), 3116 (M+ꢀPPh3), 2854 (M+ꢀ2PPh3),
2592 (M+ꢀ3PPh3), 2330 (M+ꢀ4PPh3).
C
96H80P4S4CdCu2: C, 66.8; H, 4.67. Found: C, 66.2; H, 4.64%. UV–Vis
(DMF, kmax/nm, 10ꢀ3 /Mꢀ1 cmꢀ1): 268 (11.4), 343 (1.9). IR (KBr
disc, cmꢀ1):
(P–C) 1079 (s), m(C–S) 694 (s), m(Cu–P) 446 (w) and
e
2.11. X-ray crystallography
m
435 (w). 1H NMR (DMSO-d6, ppm): d 7.20–7.56 (m, 80H, Ph). 31P
NMR (DMSO-d6, ppm): d ꢀ3.71 (s). MS (FAB): m/z 1725 (M+).
Crystallographic data and experimental details for [Hg(
{CuCl(PPh3)2}]ꢁ2dmf (1ꢁ2dmf), [Hg( -SePh)2{CuCl(PPh3)2}]ꢁ2dmf
(2ꢁ2dmf), and [Hg(SPh)( -SPh)( -Cl)Ag(PPh3)2]ꢁdmf (3ꢁdmf) in
Table 1 and those for [Cd( -SPh)4{Cu(PPh3)2}] (5), [Cd( -SePh)4
{Cu(PPh3)2}] (6), [Cd( -SPh)4{Ag-(PPh3)2}] (7), [Cd3( -SPh)6(l3
-SePh)6( 3-SePh)4
l-SPh)2
l
l
l
2.7. Preparation of [Cd(
l-SePh)4{Cu(PPh3)2}2] (6)
l
l
l
l
-
The method was similar to that used for 5, employing
[Me4N][Cd(SePh)4] (177 mg, 0.20 mmol) in instead of
[Me4N]2[Cd(SPh)4]. Colorless blocks were obtained. Yield: 207 mg
SPh)4(AgPPh3)4]ꢁ0.5dmf (8ꢁ0.5dmf), and [Cd3(
l
l
(AgPPh3)4]ꢁ0.5dmf (9ꢁ0.5dmf) in Table 2 are summarized. Intensity
data were collected on a Bruker SMART APEX 2000 CCD diffractom-
(54%). Anal. Calc. for C96H80P4Se4CdCu2: C, 60.3; H, 4.22. Found:
eter using graphite-monochromated MoK
a
radiation (k =
C, 60.1; H, 4.18%. UV–Vis (DMF, kmax/nm, 10ꢀ3
e
/Mꢀ1 cmꢀ1): 266
0.71073 Å) at 293(2) K. The collected frames were processed with
the software SAINT [26]. The data was corrected for absorption
using the program SADABS [27]. Structures were solved by the direct
methods and refined by full-matrix least-squares on F2 using the
SHELXTL software package [28]. The metal, phosphorous, sulfur, sele-
nium, and chloride atoms in the complexes were refined anisotrop-
ically. The positions of all hydrogen atoms were generated
geometrically (Csp3–H = 0.96 and Csp2–H = 0.93 Å), assigned isotro-
pic thermal parameters, and allowed to ride on their respective
parent carbon or nitrogen atoms before the final cycle of least-
squares refinement. The solvent molecules in 3ꢁdmf and 7ꢁ0.5dmf
were isotropically refined without hydrogen atoms due to disorder.
The phenyl rings of ligands in complexes 5–7 were refined with
bond-length restraints. The Flack parameter values of 0.00(5),
0.01(2) and ꢀ0.04(13) for 5, 6 and 7, respectively, indicate that
the correct enantiomorphs have been selected in the structures.
The largest peak in the final difference map had height of
3.839 e Åꢀ3 in 4 is in the vicinity of the Hg atom. Atomic coordi-
nates, complete bond distances and angles, and anisotropic ther-
mal parameters of all non-hydrogen atoms for all three clusters
are available as Supplementary materials.
(9.7), 355 (1.2), 367 (sh). IR (KBr disc, cmꢀ1):
m
m(P–C) 1086 (s),
(C–Se) 662 (s), m
(Cu–P) 443 (w) and 436 (w). 1H NMR (DMSO-
d6, ppm): d 7.21–7.54 (m, 80H, Ph). 31P NMR (DMSO-d6, ppm): d
ꢀ3.68 (s). MS (FAB): m/z 1913 (M+).
2.8. Preparation of [Cd(l-SPh)4{Ag(PPh3)2}2] (7)
The method was similar to that used for 5, employing
[Ag(PPh3)2NO3] (278 mg, 0.40 mmol) in instead of [Cu(PPh3)2NO3].
Colorless blocks were obtained. Yield: 178 mg (49%). Anal. Calc. for
C
96H80P4S4CdAg2: C, 63.6; H, 4.44. Found: C, 63.2; H, 4.43%. UV–Vis
(DMF, kmax/nm, 10ꢀ3 /Mꢀ1 cmꢀ1): 261 (10.3), 345 (1.6). IR (KBr
disc, cmꢀ1):
(P–C) 1084 (s),
e
m
m(C–S) 691 (s), m(Ag–P) 423 (w) and
415 (w). 1H NMR (DMSO-d6, ppm): d 7.24–7.60 (m, 80H, Ph). 31P
NMR (DMSO-d6, ppm): d ꢀ4.85 (s). MS (FAB): m/z 1814 (M+).
2.9. Preparation of [Cd3(
(8ꢁ0.5dmf)
l
-SPh)6(
l
3-SPh)4(AgPPh3)4]ꢁ0.5dmf
To a solution of [Me4N]2[Cd(SPh)4] (280 mg, 0.40 mmol) in
MeCN (15 mL) was added [Ag(PPh3)2NO3] (278 mg, 0.40 mmol) in
CH2Cl2 (15 mL) with stirring. The mixture was stirred at room tem-
perature for 45 min. Fine white solids gradually formed and then
suspension solution was stirred for additional 2 h. The precipitates
were collected by suction filtration and washed twice with 10 mL
portions of diethyl ether. White air-stable solids were further
recrystallized from DMF/MeCN to give colorless block crystals of
2.12. Optical measurements
A DMF solution of 1.48 ꢂ 10ꢀ4 mol dmꢀ3 of 8 or 9 was placed in
a 1 mm quartz cuvette for optical measurements. The optical lim-
iting characteristics along with nonlinear absorption and refraction
was investigated with a linearly polarized laser light (k = 532 nm,
pulse width = 7 ns) generated from a Q-switched and frequency-
doubled Nd:YAG laser. The spatial profiles of the optical pulses
were nearly GAUSSIAN. The laser beam was focused with a 25-cm
focal-length focusing mirror. The radius of the laser beam waist
8ꢁ0.5dmf in
132H110P4S10–Cd3Ag4ꢁ0.5(C3H7NO): C, 54.4; H, 3.88; N, 0.24.
Found: C, 54.2; H, 3.83; N, 0.23%. UV–Vis (DMF, kmax/nm, 10ꢀ3
Mꢀ1 cmꢀ1): 264 (11.4), 350 (2.1), 361 (sh). IR (KBr disc, cmꢀ1):
(C–H) 3051 (m), (C@O) 1669 (s), (P–C) 1081 (s), (C–S) 694
(s),
(Ag–P) 419 (w) and 411 (w). 1H NMR (DMSO-d6, ppm): d
a week. Yield: 153 mg (38%). Anal. Calc. for
C
e/
m
m
m
m
was measured to be 30
5 l
m (half-width at 1/e2 maximum in
m
irradiance). The incident and transmitted pulse energy were mea-
sured simultaneously by two Laser Precision detectors (RjP-735
energy probes) communicating to a computer via an IEEE interface
[29,30], while the incident pulse energy was varied by a Newport
Com. Attenuator. The interval between the laser pulses was chosen
2.96 (s, 1.5H, Me2NCHO), 7.12–7.64 (m, 110H, Ph), 8.01 (s, 0.5H,
CHO). 31P NMR (DMSO-d6, ppm): d ꢀ4.86 (s). MS (FAB): m/z 2909
(M+), 2647 (M+ꢀPPh3), 2385 (M+ꢀ2PPh3), 2123 (M+ꢀ3PPh3),
1861 (M+ꢀ4PPh3).

188
C. Xu et al. / Polyhedron 33 (2012) 185–193
Table 1
Crystallgraphic data and experimental details for [Hg(
[Hg(SPh)( -SPh)(
-Cl)Ag(PPh3)2]ꢁdmf (3ꢁdmf).
l
-SPh)2{CuCl(PPh3)2}2]ꢁ2dmf (1ꢁ2dmf), [Hg(
2ꢁ2dmf
l
-SePh)2{CuCl(PPh3)2}2]ꢁ2dmf (2ꢁ2dmf), and
3ꢁdmf
l
l
1ꢁ2dmf
Formula
Formula weight
C
90H84N2O2Cl2P4S2HgCu2
C90H84N2O2Cl2P4Se2HgCu2
1905.96
C51H47NOClP2S2HgAg
1159.87
1812.16
Unit cell dimensions
a (Å)
b (Å)
c (Å)
10.8500(4)
12.9693(4)
14.9390(5)
78.964(2)
82.705(2)
88.327(2)
2046.57(12)
1
10.9161(2)
12.9737(3)
14.9262(3)
79.535(1)
82.877(1)
88.893(1)
7062.67(7)
1
10.8157(2)
13.3522(2)
17.8945(3)
111.674(1)
90.566(1)
95.747(1)
2386.36(7)
2
a
(°)
b (°)
c
(°)
V (Å3)
Z
Crystal system
Space group
triclinic
P1
1.470
triclinic
P1
1.534
triclinic
P1
1.614
ꢀ
ꢀ
ꢀ
qcalc (g cmꢀ3
)
Number of reflections
37974
38441
44650
Number of independent reflections
9397
9451
10957
[I > 2.0
All data
r
(I)]
R1 = 0.0213, wR2 = 0.0529
R1 = R1, 0.0257, wR2 = 0.0551
R1 = 0.0222, wR2 = 0.0523
R1 = 0.0296, wR2 = 0.0554
R1 = 0.0290, wR2 = 0.0757
R1 = 0.0358, wR2 = 0.0792
Table 2
Crystallgraphic data and experimental details for [Cd(
l
-SPh)4{Cu(PPh3)2}2] (5), [Cd(
l
-SePh)4{Cu(PPh3)2}2] (6), [Cd(
8ꢁ0.5dmf
l
-SPh)4{Ag(PPh3)2}2] (7), [Cd3(
l-SPh)6(l3-
SPh)4(AgPPh3)4]ꢁ0.5dmf (8ꢁ0.5dmf), and [Cd3(l-SePh)6(l3-SePh)4(AgPPh3)4]ꢁ0.5dmf (9ꢁ0.5dmf).
5
6
7
9ꢁ0.5dmf
Formula
C
96H80P4S4CdCu2
C96H80P4Se4CdCu2
1912.80
C96H80P4S4CdAg2
1813.86
C133.5H113.5N0.5O0.5P4S10Cd3Ag4 C133.5H113.5N0.5O0.5P4Se10Cd3Ag4
Formula weigh
Unit cell dimensions
a (Å)
b (Å)
c (Å)
1725.20
2945.91
3414.91
15.1926(2)
18.1694(7)
15.2747(3)
18.2172(8)
15.3743(2)
18.2442(6)
15.7185(3)
17.2345(3)
27.4075(7)
98.770(1)
94.265(1)
117.089(1)
6445.1(2)
2
15.8257(6)
17.3414(7)
27.5999(11)
77.186(2)
85.709(2)
63.513(2)
6608.1(5)
2
a
(°)
b (°)
c
(°)
V (Å3)
4193.77(18)
2
4250.4(2)
2
4312.37(16)
2
Z
Crystal system
Space group
tetragonal
P-421/c
1.366
tetragonal
P-421/c
1.495
tetragonal
P-421/c
1.397
triclinic
P1
1.518
triclinic
P1
1.716
ꢀ
ꢀ
qcalc (g cmꢀ3
)
Number of reflections
Number of independent
reflections
15213
2649
15569
2613
16139
2731
121007
29419
123031
30206
[I > 2.0
All data
Flack value
r
(I)]
R1 = 0.0515,
wR2 = 0.0986
R1 = 0.1022,
wR2 = 0.1168
0.00(5)
R1 = 0.0367,
wR2 = 0.0619
R1 = 0.0546,
wR2 = 0.0835
0.01(2)
R1 = 0.0464,
wR2 = 0.1235
R1 = 0.0944,
wR2 = 0.1651
ꢀ0.04(13)
R1 = 0.0420, wR2 = 0.0944
R1 = 0.0745, wR2 = 0.1564
R1 = 0.0766, wR2 = 0.1097
R1 = 0.0939, wR2 = 0.1785
–
–
to be 10 s to avoid the influence of thermal and long-term effects.
The details of the set-up can be found elsewhere [31,32].
of [Hg(EPh)2] with 2 equivalents of [Cu(PPh3)2Cl] in CH2Cl2/MeCN
resulted in formation of the white precipitates which were recrys-
tallized from DMF/MeCN to afford the trinuclear Hg/Cu/S(Se) com-
pounds [Hg(
l-EPh)2{CuCl(PPh3)2}2] (E = S 1, Se 2) [see Eq. (1)].
3. Results and discussion
½HgðEPhÞ2ꢃ þ 2½CuðPPh3Þ2Clꢃ ! ½Hgð
l-EPhÞ2fCuClðPPh3Þ2g2ꢃ
3.1. Syntheses and reactions
E ¼ S1
Se2
[Hg(EPh)2] (E = S, Se, Te) as the starting materials can generate
new compounds such as the binary and ternary clusters [17–19].
For example, the sulfide and selenide derivatives react with equi-
molar amounts of HgCl2 in pyridine (py) to give the metallacyclic
ð1Þ
As expected, [Hg(EPh)2] as a precursor binds to [Cu(PPh3)2Cl]
species via the sulfur or selenium atoms of the PhEꢀ moieties
whilst the coordination geometry of the central mercury atom
was kept. Reaction of [Hg(EPh)2] with [Cu(PPh3)2NO3] in CH2Cl2/
MeCN also gave the large white precipitates intermediately, indic-
ative of formation of polynuclear hetero-metallic complexes.
Unfortunately, it is very difficult to recrystallize these complexes
existing insoluble precipitates. A similar reaction of [Hg(EPh)2]
with [Ag(PPh3)2Cl] gave rise to isolation of the dinuclear com-
compounds [Hg4Cl4(l
-ER)4(py)n] (E = S, R = tBu, n = 2; E = Se,
R = Et, n = 4; E = Se, R = tBu, n = 4) [18e,f]. Similarly, the reaction
of [Hg(TePh)2] with HgBr2 in pyridine produces the large cluster
[Hg6(l-Br2)Br2(l-TePh)8(py)2] with six-membered rings [Hg3(l-
TePh)3] [17b]. Interestedly, the reaction of [Hg(TePh)2] with
[Ag(L)nX] (X = Clꢀ, NO3ꢀ; L = PMePh2, PPh3, DMF) in a ratio of 1:2
at room temperature affords the cluster [Hg6Ag4(TePh)16] with
incorporation of Ag(I) into the cluster structure [17a]. Treatment
pounds [Hg(SePh)(l-SePh)(l-Cl)Ag(PPh3)2] (E = S 3, Se 4) [see Eq.

C. Xu et al. / Polyhedron 33 (2012) 185–193
189
(2)] in which the coordination geometry of the mercury atom
changes from two to three coordinate due to the chloride of the
[Ag(PPh3)2Cl] specie involved in coordination with the mercury
atom. It is very difficult to recrystallize the white precipitates
formed a quick mixture of [Hg(EPh)2] and [Ag(PPh3)2NO3], sugges-
tive of the polynuclear heterometallic Hg/Ag/S(Se) clusters proba-
bly existing in insoluble precipitates.
Cd3(
l
3-EPh) core. Subsequently, coordination of four [Ag(PPh3)]+
3-EPh)(EPh)9]4ꢀ anion via sulfur and sele-
fragments with the [Cd3(
l
nium atoms of the peripheral thiophenolates and selenophenolates
gave the heptanuclear complexes 8 and 9, respectively [see Eq. (4)].
Complexes 1–9 are air-stable in both the solid-state and solution,
and soluble in very polar solvents such as dimethyl sulfoxide
(DMSO) and dimethylformide (DMF) and slightly soluble in CH2Cl2.
½CdðEPhÞ4ꢃ2ꢀ þ 2½MðPPh3Þ ꢃþ
!
½Cdð -EPhÞ4fMðPPh3Þ2g2ꢃ
l
½HgðEPhÞ2ꢃ þ ½AgðPPh3Þ2Clꢃ ! ½HgðEPhÞð
l
-EPhÞð -ClÞAgðPPh3Þ2ꢃ
l
2
E ¼ S 3
Se4
E ¼ S M ¼ Cu 5
ð3Þ
Se
S
Cu 6
Ag 7
ð2Þ
ð4Þ
The analogous [Cd(EPh)2] has been used to react with CdX2
(X = Cl, Br) in the presence of PPh3 to give the tetranuclear ada-
mantanoid-type clusters [Cd4(SePh)x(PPh3)X]n (X = Cl, Br; x = 6, 7)
[21], however, no heterometallic compound with [Cd(EPh)2] as a
precursor has been reported yet. Nevertheless, attempts to synthe-
size the heterometallic Cd/Cu(Ag)/S(Se) complexes by reacting
[Cd(EPh)2] with [M(PPh3)2NO3] (M = Cu, Ag) species were unsuc-
cessful. The possible reason may be due to the crystalline product
[Cd(EPh)2] itself being inorganic polymer with the typical
[Cd4(EPh)6] adamantane-like cage [20]. To isolate the heterometallic
Cd/Cu(Ag)/S(Se) compounds successfully, the homoleptic tetrahe-
dral species [Cd(EPh)4]2ꢀ (E = S, Se) were used to react with 2 equiv-
alents of [Cu(PPh3)2NO3]. As expected, two [Cu(PPh3)2]+ fragments
chelate to the opposite edges of a tetrahedral [Cd(EPh)4]2ꢀ moiety
via the sulfur or selenium atoms of the PhEꢀ species, resulting in for-
3.2. Spectroscopic properties
The characteristic bands for the thiophenolato complexes
1ꢁ2dmf, 3ꢁdmf, 5, 7, and 9ꢁ0.5dmf were found at 1079–1084 and
691–694 cmꢀ1 in the IR spectra, whereas the corresponding bands
for the selenophenolato complexes 2ꢁ2dmf, 4ꢁdmf, 6 and 8ꢁ0.5dmf
were observed at 1081–1086 and 662–665 cmꢀ1 in the IR spectra.
The respective former bands are assignable to the mode of phenyl
ring coupled with C–S or C–Se and the respective latter bands are
due to C–S or C–Se bonds. The Cu–P stretching modes of the com-
plexes can be identified as weakly sharp peaks in the range of
435–448 cmꢀ1 in the spectra of complexes 1ꢁ2dmf, 2ꢁ2dmf, 5 and
6, while the Ag–P stretching modes of the complexes can be identi-
fied as weakly sharp peaks in the range of 413–425 cmꢀ1 in the
spectra of complexes 3ꢁdmf, 4ꢁdmf, 7, 8ꢁ0.5dmf, and 9ꢁ0.5dmf. The
metal–sulfur or –selenium stretching modes of the thio- and sele-
no-metallic complexes can be identified since they appear as weak-
er bands in the low-wavenumber region below 400 cmꢀ1 in the IR
spectra. The weak bridging M–S and M–Se vibrations are observed
in the ranges of 310–325 and 285–300 cmꢀ1, respectively, in the IR
spectra of the above complexes. The broad bands at ca. 1665 cmꢀ1
mation of the neutral linear trinuclear complexes [Cd(l-EPh)4
{Cu(PPh3)2}2] (E = S 5, Se 6). A similar reaction of [Me4N]2[Cd(SPh)4]
with 2 equivalents of [Ag(PPh3)2NO3] gave an analogous trinuclear
complex [Cd(l-SPh)4{Ag(PPh3)2}2] (7) [see Eq. (3)], whereas the
reaction of [Me4N]2[Cd(EPh)4] with an equivalent amount of
[Ag(PPh3)2NO3] in the similar conditions surprisingly afforded the
neutral heptanuclear complexes [Cd3(
l
-EPh)6(
l
3-EPh)4(AgPPh3)4]
for m(C@O) in the IR spectra indicated the presences of the lattice
(E = S 8, Se 9). These are the first examples of high nuclearity cad-
mium–silver complexes with thiolate and selenolate ligands. In
the present system, it seems that the self-assembly of three
[Cd(EPh)4]2ꢀ anions, under the displacement of two PhEꢀ species,
dimethylformides in the crystalline products 1ꢁ2dmf, 2ꢁ2dmf,
3ꢁdmf, 4ꢁdmf, 8ꢁ0.5dmf, and 9ꢁ0.5dmf. The main features in the elec-
tronic absorption spectra in DMF solution at room temperature are
structured bands at 261–269 nm, to which aromatic
tions make the major contribution, and low energy absorption
p ?
p⁄ transi-
constructs
a new [Cd3(l a stable
3-EPh)(EPh)9]4ꢀ anion with

190
C. Xu et al. / Polyhedron 33 (2012) 185–193
bands at 342–359 nm which are assigned to sulfur or selenium-to-
copper or silver charge transfer [33].
The 1H NMR spectra for all complexes are quite similar to those
of the free ligands and solvent molecules, indicating that all com-
plexes are diamagnetic. The 31P{1H} NMR resonances for com-
plexes 1–9 show a single peak downfield from that of the free
PPh3 ligand, which may be ascribed to the different phosphorus
atoms in each complex with the same coordination environment.
The 31P resonances slightly shift upfield by the comparison of cop-
per complexes with silver complexes with same structural types.
The FAB+ mass spectra of compounds 1–9 exhibit molecular ions
corresponding to M+, (M+ꢀhalides) and (M+ꢀPPh3) with the char-
acteristic isotopic distribution patterns.
3.3. Crystal structures
The crystal structures of 1ꢁ2dmf, 2ꢁ2dmf, 3ꢁdmf, 5, 6, 7,
8ꢁ0.5dmf, and 9ꢁ0.5dmf have been established by X-ray crystallog-
raphy. Selected structural parameters for 1ꢁ2dmf, 2ꢁ2dmf, 3ꢁdmf, 5,
6 and 7 are complied in Table S1 for comparison, and selected bond
lengths and angles for 8ꢁ0.5dmf and 9ꢁ0.5dmf are given in Tables S2
and S3, respectively. The asymmetric unit in the crystal structures
of 1ꢁ2dmf and 2ꢁ2dmf consists of one neutral complex and two sol-
vent molecules. Molecular structures of the neutral complexes 1
and 2 possess a symmetric center through the mercury atom (see
Fig. 1). Both structures can be described as constituted by
[Hg(EPh)2] units symmetrically ligated by two copper atoms via
the sulfur atoms of the PhSꢀ ligands in 1 and the selenium atoms
of the PhSeꢀ ligands in 2, forming the new trinuclear heterometal-
lic complexes. The coordination spheres of the mercury atoms in
Fig. 2. Molecular structure of [Hg(SPh)(l-SPh)(l-Cl)Ag(PPh3)2] (3), showing 30%
thermal ellipsoids. The carbon atoms are represented as sticks for clarity.
0
2.6079(8) ÅA, respectively. There is an obvious deviation among
four angles in the ring [S(2)–Hg(1)–Cl(1) = 85.72(2)°, S(2)–Ag(1)–
Cl(1) = 84.61(2)°, Hg(1)–S(2)–Ag(1) = 89.71(2)° and Hg(1)–Cl(1)–
Ag(1) = 83.00(2)°]. The coordination about mercury atom is
slightly distorted T-shape, the three sites being occupied by one
bridging sulfur atom, one bridging chloride atom and one terminal
0
sulfur atom. The terminal Hg–S bond length of 2.3382(10) ÅA is
obviously 0 shorter than the bridging Hg–S bond length of
2.4042(8) ÅA. The S(1)–Hg(1)–S(2) angle is 162.87(3)°, which obvi-
ously deviates from the flat angle in [Hg(SPh)2] due to the coordi-
nation of chloride atom to the mercury atom. The Cl–Hg–S angle
involving the terminal PhSꢀ moiety (106.97(4)°) is significantly
bigger than that involving the bridging PhSꢀ moiety (85.72(2)°).
The coordination around the silver atom is a distorted tetrahedron,
main distortions are due to the Cl(1)–Ag(1)–S(2) and P(1)–Ag(1)–
P(2) angles of 84.61(2)° and 1205.03(3)°, respectively. The average
both structures are kept with linearity and mercury atoms are
0
coordinated by two sulfur atoms in 1ꢁ2dmf (Hg–S = 2.3699(4) ÅA)
0
and two selenium atoms in 2ꢁ2dmf (Hg–Se = 2.4740(2) ÅA) related
by the twofold axes. Both S–Hg–S and Se–Hg–Se angles are
180.0°. The coordination geometry of the copper atom in 1ꢁ2dmf
or 2ꢁ2dmf is highly distorted tetrahedral with the angles around
copper atom ranging from 89.27(2)° to 122.63(2)° in 1ꢁ2dmf and
Ag–P bond length of 2.4524(7) ÅA in 3ꢁdmf is in the expected range.
0
from 89.30(2)° to 122.93(2)° in 2ꢁ2dmf. The Cu–S bond length
0
The two metal atoms are 3.608(2) ÅA apart and are thus non-
bonded.
and the Hg–S–Cu angle in 1ꢁ2dmf are 2.4341(5) ÅA and 99.14(2)°,
respectively, while the Cu–Se bond length and the Hg–Se–Cu angle
0
Heterobimetallic Cd/Cu/S(Se) complexes 5 and 6 are isostruc-
tural with heterobimetallic Cd/Ag/S complex 7. Figs. 3 and 4 show
perspective views of complexes 6 and 7, respectively. Quite few
structurally characterized heterobimetallic complexes containing
the [Cd(EPh)4]2ꢀ (E = S, Se) anions and coinage metals have been
synthesized to date [34]. Related coinage metal heterometalates
in 2ꢁ2dmf are 2.5450(3) ÅA and 95.81(1)°, respectively.
Fig. 2 shows a perspective view of complex 3. The asymmetric
unit of the crystal structure consists of one neutral complex and
one solvent molecule in the lattice. Compound 3 is a dinuclear het-
erometallic complex with a non-planar HgSAgCl four-membered
ring. In the ring, the Hg(1)–S(1) and Hg(1)–Cl(1) bond lengths
0
[(l-WSe4){M(PMe2Ph)2}2] (M = Cu, Ag, Au) with symmetric
are 2.3382(10) and 2.8316(8) ÅA, respectively, accordingly, the
Ag(1)–S(1) and Ag(1)–Cl(1) bond lengths are 2.7030(8) and
Fig. 1. Molecular structure of [Hg(l-SePh)2{CuCl(PPh3)2}2] (2), showing 30%
Fig. 3. Molecular structure of [Cd(
l-SePh)4{Cu(PPh3)2}2] (5), showing 30% thermal
thermal ellipsoids. The carbon atoms are represented as sticks for clarity.
ellipsoids. The carbon atoms are represented as sticks for clarity.

C. Xu et al. / Polyhedron 33 (2012) 185–193
191
0
lengths are 2.417(3), 2.534(2) and 2.654(4) ÅA for 5, 6 and 7, respec-
tively. Accordingly, the Cu–S–Cd, Cu–Se–Cd and Ag–S–Cd angles
are 88.29(9), 85.19(5) and 84.63(12)° for 5, 6 and 7, respectively.
Similar to other linear trinuclear heterometallic complexes, the
three metal atoms in complexes 5–7 are collinear. Furthermore,
0
the Cuꢁ ꢁ ꢁCd distances are 3.470(2) in 5 and 3.516(2) ÅA in 6, and
0
the Agꢁ ꢁ ꢁCd distance is 3.498(2) ÅA in 7, which are too long to be
metal–metal interaction.
Complex 8ꢁ0.5dmf is isostructural with complex 9ꢁ0.5dmf. The
molecular structures consist of the neutral heptanuclear heterobi-
metallic complexes and lattice solvents. A perspective view of the
Cd/Ag/Se complex 9, as represented, is shown in Fig. 5. The struc-
tures of the neutral complexes 8 and 9 may be described as three
[(AgPPh3)]+ fragments side-ligated and one [(AgPPh3)]+ fragment
side-capped with the trinuclear cadmium-thio(seleno)phenolate
[Cd3(
phenolates in 8 and the selenium atoms of selenophenolates in 9.
Each cadmium atom is coordinated to two -EPh and two 3-EPh
l-EPh)6(l
3-EPh)4]4ꢀ moieties via the sulfur atoms of thio-
Fig. 4. Molecular structure of [Cd(l-SPh)4{Ag(PPh3)2}2] (7), showing 30% thermal
ellipsoids. The carbon atoms are represented as sticks for clarity.
l
l
species in a distorted tetrahedral geometry, which is indicated by
the S–Cd–S angles in the ranges of 96.36(3)–126.60(4)° for 8 and
the Se–Cd–Se angles in the ranges of 94.50(5)–126.24(7)° for 9.
[M(PMe2Ph)2]+ fragments have been previously reported by Ibers
and co-workers [35]. A similar linear metal skeleton has been ob-
served in some heterometallic trinuclear complexes with transi-
tion metal as the central metal, such as [M(l-SAr)6(CuPPh3)2]
(M = W, Mo, U, Sn; Ar = Ph, p-C6H4Me, p-C6H4F, p-C6H4Cl, p-
The average Cd–
average Cd– 2-S bond length of 2.492(1) Å in 8, similarly, the aver-
age Cd– 3-Se bond length of 2.793(2) Å is also longer than the
average Cd– 2-Se bond length of 2.596(2) Å in 9. The coordination
l3-S bond length of 2.603(1) Å is longer than the
l
l
l
C6H4Br) [12b,36]. The solid-state structures of complexes 5–7 con-
geometry of the silver atoms remains a highly distorted tetrahe-
dral, with the band angles in the ranges 92.30(3)–124.77(4)° and
91.74(6)–123.26(12)° for 8 and 9, respectively. The Ag–P bond
lengths, in the range of 2.447(1)–2.473(4) Å, are not clearly influ-
enced by the different silver coordination environments in both
complexes. It is interesting to note that there are three CdE2Ag
approximately co-planar four-membered rings, three CdE3Ag2
and three Cd2E3Ag non-planar six-membered rings in both com-
tain two symmetry-related [(PPh3)2M(l-EPh)2] (M = Cu, Ag; E = S,
Se) units with the cadmium at the center of inversion. The geome-
try around the central cadmium atoms in three complexes is highly
distorted tetrahedral, indicated by the S–Cd–S bond angles ranging
from 88.25(15)° to 121.02(9)° in 5, the Se–Cd–Se bond angles rang-
ing from 91.80(7)° to 118.97(4)° in 6, and the S–Cd–S bond angles
ranging from 98.1(2)° to 115.42(11)° in 7. The Cd–S bond distances
0
0
of 2.563(3) ÅA in 5 and 2.540(4) ÅA in 7 are compared with that of
0
plexes. Similar to 7 and other related Cd/Ag/S(Se) complexes, the
2.541(3) ÅA (av.) in [Me4N0]2[Cd(SPh)4]. Similarly, the Cd–Se bond
0
distances 0 of Agꢁ ꢁ ꢁCd separation in
8 (3.379(5) ÅA) and in 9
(3.377(2) ÅA) are too long for the metal–metal bond.
distance 0 of 2.6593(15) ÅA in
6 is compatible with that of
2.649(3) ÅA (av.) in [Me4N]2[Cd(SePh)4] [22]. All coinage metals in
three complexes have a distorted tetrahedral geometry, being
bonded to two phosphorus of the PPh3 ligands and two sulfur or
selenium atoms of PhEꢀ groups. The Cu–S, Cu–Se and Ag–S bond
3.4. NLO properties
Complexes 1–9 have a low absorbance at 532 nm, which may
promise low intensity loss and small temperature changes by pho-
ton absorption when the laser pulse propagates in these heterome-
tallic complexes. It has been noted that the neutral polynuclear
argento-selenometallic compounds with
r-donating phosphine li-
gands were found to exhibit the strong nonlinear optical absorp-
tive and refractive effects along with the good photostability
[37]. In this connection, the NLO properties of the heptanuclear
Cd/Ag/S(Se) complexes 8 and 9 with new structural types were ini-
tially selected to be investigated by using the z-scan technique
[29–31]. The nonlinear absorption component was evaluated
under an open aperture configuration. Theoretical curves of trans-
mittance against the z-position, Eqs. (5) and (6), were fitted to the
observed z-scan data
Z
1
1
s2
TðZÞ ¼
ln½1 þ qðzÞꢃeꢀ
ds
ð5Þ
p
1=2qðZÞ
ꢀ1
a0L
ð1 ꢀ eꢀ
Þ
qðZÞ ¼
a2IiðZÞ
ð6Þ
a0
by varying the effective third-order NLO absorptivity a2 value,
where the experimentally measured a0 (linear absorptivity), L (the
optical path of sample) and Ii(Z) (the on-axis irradiance at z-posi-
tion) were adopted. The solid line in Fig. S5 (up) is the theoretical
curve calculated with
a
2 = 5.26 ꢂ 10ꢀ4 cm/W for the concentration
Fig. 5. Molecular structure of [Cd3(
thermal ellipsoids. All phenyl rings were omitted for clarity.
l-SePh)6(l3-SePh)4(AgPPh3)4] (9), showing 30%
of 1.48 ꢂ 10ꢀ4 M for 8 in a DMF solution. The non-linear refractive

192
C. Xu et al. / Polyhedron 33 (2012) 185–193
component of 8 was assessed by dividing the normalized z-scan
data obtained in the close-aperture configuration by those obtained
in the open-aperture configuration. The nonlinear refractive compo-
nent plotted with the filled squares in Fig. S4 (down) was assessed
by dividing the normalized z-scan data obtained under the closed
aperture configuration by the normalized z-scan data obtained un-
der the open aperture configuration. The valley and peak occur at
about equal distances from the focus. It can be seen that the differ-
ence in valley–peak positions dZV–P is 7.52 mm and the difference
between normalized transmittance values at valley and peak posi-
tions dTV–P = 0.41 for 8. These results suggest an effectively strong
third-order optical nonlinearity [31,32]. The solid curve is an eye
guide for comparison where the effective nonlinear refractivity n2
value estimated therefore is 3.47 ꢂ 10ꢀ9 esu for 8. Similarly, the so-
lid line in Fig. S5 (up) is the theoretical curve calculated with
plementary data associated with this article can be found, in the
online version, at doi:10.1016/j.poly.2011.11.046.
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CCDC 827733, 827734, 827735, 827736, 827737, 827738,
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