Photophysical properties, electronic and crystal structures of luminescent diphosphine digold(I)-pyridine-2-thiolate complexes

Article abstract of DOI:10.1016/j.ica.2003.11.002

Treatment of diphosphine digold(I) complexes, PP(AuCl)₂ [PP=bis(diphenylphosphino)methane, dppm; 1,6-bis(diphenylphosphino)hexane, dpph], with two equivalents of pyridine-2-thiol (HNS) in the presence of NaOCH₃ affords two luminescent diphosphine digold(I)-pyridine-2- thiolate complexes, dppm(AuSN)₂ (1) and dpph(AuSN)₂ (2), respectively. Both crystal structures have been determined by crystallographic studies. The intramolecular aurophilic contact of 3.0478(3) ? is observed in the crystal structure of 1, whereas there is not any aurophilic interaction present in the crystal lattices of 2. At room temperature, 1 shows a low-energy emission at ca. 660 nm as well as a very weak high-energy emission at ca. 496 nm in the solid state, but 2 shows only a strong high-energy one at ca. 482 nm. Thus, the emission energy strongly dependent on the Au(I)?Au(I) interaction can be demonstrated in the diphosphine digold(I) thiolates studied herein.

Full text of DOI:10.1016/j.ica.2003.11.002

Inorganica Chimica Acta 357 (2004) 1405–1410
www.elsevier.com/locate/ica
Photophysical properties, electronic and crystal structures
of luminescent diphosphine digold(I)-pyridine-2-thiolate complexes q
a,
a
b
b
Biing-Chiau Tzeng *, Ju-Hsiou Liao , Gene-Hsiang Lee , Shie-Ming Peng
a
Department of Chemistry and Biochemistry, National Chung Cheng University, 160 San-Hsin, Min-Hsiung, Chia-Yi 621, Taiwan
b
Department of Chemistry, National Taiwan University, Taipei, Taiwan
Received 16 August 2003; accepted 3 November 2003
Abstract
Treatment of diphosphine digold(I) complexes, PP(AuCl)2 [PP ¼ bis(diphenylphosphino)methane, dppm; 1,6-bis(diph-
enylphosphino)hexane, dpph], with two equivalents of pyridine-2-thiol (HNS) in the presence of NaOCH3 affords two luminescent
diphosphine digold(I)-pyridine-2-thiolate complexes, dppm(AuSN)2 (1) and dpph(AuSN)2 (2), respectively. Both crystal structures
ꢀ
have been determined by crystallographic studies. The intramolecular aurophilic contact of 3.0478(3) A is observed in the crystal
structure of 1, whereas there is not any aurophilic interaction present in the crystal lattices of 2. At room temperature, 1 shows a low-
energy emission at ca. 660 nm as well as a very weak high-energy emission at ca. 496 nm in the solid state, but 2 shows only a strong
high-energy one at ca. 482 nm. Thus, the emission energy strongly dependent on the Au(I)ꢀ ꢀ ꢀAu(I) interaction can be demonstrated
in the diphosphine digold(I) thiolates studied herein.
Ó 2003 Elsevier B.V. All rights reserved.
Keywords: Luminescent; Aurophilicity; Vapochromic; Thiolate; Vibronic
1. Introduction
may be recognized not only from short gold(I)ꢀ ꢀ ꢀgold(I)
distances and novel structural features, but also from
intriguing electronic absorption and luminescence
properties. It is becoming clear that the gold(I)ꢀ ꢀ ꢀgold(I)
bonding interaction is responsible for the relevant
transitions and luminescence has thus become an im-
portant diagnostic tool for aurophilicity [12]. Recently, a
spectacular experiment carried out by Balch and co-
workers [3a] has demonstrated that luminescence of
gold(I) complexes can be triggered by the solvation of
the donor-free solid substrate either from the vapor
phase or by dissolving the material in a solvent. In the
meantime, a remarkable example of the strong solvent
dependence of the luminescence of a gold(I) compound
in solution has been observed by Che and co-workers
[10d]. Moreover, an unusual chromic luminescence be-
havior linked to a structural change in the solid state
induced by exposure to the vapor phase of volatile or-
ganic compounds (VOCs) was also observed by Eisen-
berg and co-workers [13]. The ‘‘luminescent switch’’ for
the detection of VOCs using gold(I) dimers following
the pioneering work by Mann and co-workers [14] on
Aurophilicity, the propensity for closed-shell d10
gold(I) centers to form weakly bonding interactions,
leading to the fabrication of a large variety of supra-
molecular gold(I) compounds with novel structural and
intriguing spectroscopic properties, has recently been an
interesting and common phenomenon in gold(I) chem-
istry [1–10]. These interactions are typically identified by
means of X-ray diffraction studies in all cases where
gold(I)ꢀ ꢀ ꢀgold(I) distances are found to be in the same
order as the energies of standard hydrogen bonds (ca. 6–
12 kcal/gold(I)ꢀ ꢀ ꢀgold(I) at gold(I)ꢀ ꢀ ꢀgold(I) distances of
ꢀ
2.8–3.2 A) [11]. The presence of aurophilic interactions
q Supplementary data associated with this article can be found, in the
online version, at doi: 10.1016/j.ica.2003.11.002
* Corresponding author. Tel.: +88652720411ext.66414; fax:
+88652721040.
E-mail address: chebct@ccu.edu.tw (B.-C. Tzeng).
0020-1693/$ - see front matter Ó 2003 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2003.11.002

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B.-C. Tzeng et al. / Inorganica Chimica Acta 357 (2004) 1405–1410
absorption and emission spectra of vapochromic plati-
num(II) and palladium(II) compounds shows that phe-
nomena of this kind of luminescent gold(I) compounds
hold great potential for analytical applications.
ter. Dppm(AuCl)2 and dpph(AuCl)2 were prepared by
literature methods [21].
2.2. Synthesis
Among a large number of gold(I) compounds, gold(I)
thiolates are the most extensively used gold(I) complexes,
with applications in medicine and in surface technology.
Virtually all of the classical and modern drugs based on
gold(I) ions for arthritis and rheumatism have been
gold(I)–sulfur compounds [15–17]. As a first contribu-
tion to the topic of luminescent gold(I) thiolate com-
pounds, Bruce and co-workers [18] have investigated a
series of neutral and dinuclear gold(I) complexes con-
taining phosphine and thiolate (aromatic and aliphatic)
ligands, where the length of the bridging bis(phosphine)
backbone was systematically increased from dppm to
dpppn [1,5-bis(diphenylphosphino)pentane]. The num-
ber of methylene groups in the bis(phosphine) backbone
increased from 1 to 5, forming an increasingly larger
series of open-chain and dinuclear gold(I) complexes
with absorption bands at 300–360 nm as well as lumi-
nescence at 485–515 nm, which are assigned to S ! Au
charge-transfer transitions. In the meantime, Fackler
and co-workers [19] also studied a series of mononuclear
gold(I) complexes containing phosphine and thiolate
(aromatic) ligands, and all of the compounds only lu-
minesce at 77 K (485–702 nm) in the solid state, and the
excitation was also assigned to a S ! Au charge-transfer
transition. Although the presence of a Au(I)ꢀ ꢀ ꢀAu(I)
interaction in the solid state for BruceÕs system does not
significantly perturb the emission energy, Fackler and
co-workers [19] did find the emission energy affected by
Au(I)ꢀ ꢀ ꢀAu(I) interactions. However, there are only a
handful of examples demonstrating a close relationship
between the emission energy and aurophilic interaction
for gold(I) thiolates [10d,19]. Pyridine-2-thiolate (NS)
has been extensively used because of its versatile coor-
dination behavior, but only a few gold(I)-pyridine-2-
thiolate complexes are known so far [20]. Herein, we
report the photophysical properties, electronic and
crystal structures of two luminescent digold(I)-pyridine-
2-thiolate complexes of dppm and dpph, wherein the
relationship between the emission energy and aurophilic
interaction is also clarified.
[dppm(AuSN)2] (1). The reaction of NaNS (133 mg, 1
mmol), prepared by adding NaOMe (65 mg, 1.2 mmol)
to HNS (111 mg, 1 mmol) in CH2Cl2/CH3OH (1:1, 25
ml), with dppm(AuCl)2 (425 mg, 0.5 mmol) in CH2Cl2/
MeOH (1:1, 50 ml) at room temperature for 4 h gave a
pale-yellow precipitate. The precipitate was filtered off in
a vacuum and pale-yellow solids of [dppm(AuSN)2]
were obtained in a 75% yield. Single crystals were grown
by ether diffusion to a DMF solution. MS (FAB):
[dppm(AuSN)Au (M-SN)], m=e ¼ 887, 100%. 31P–{1H}
NMR (DMSO-d6, 25 °C): d 32.78 [s]. Anal. Calc. for
C35H30Au2N2P2S2: C, 42.09; H, 3.03; N, 2.81. Found:
C, 41.96; H, 2.95; N, 2.61%.
[dpph(AuSN)2] (2). 2 was prepared in a similar way
with an 86% yield except that dpph(AuCl)2 was used
instead of dppm(AuCl)2. Single crystals were grown by
ether diffusion to a DMF solution. MS (FAB):
[dpph(AuSN)Au (M-SN)], m=e ¼ 957, 100%. 31P–{1H}
NMR (DMSO-d6, 25 °C): d 35.89 [s]. Anal. Calc. for
C40H40Au2N2P2S2: C, 44.95; H, 3.77; N, 2.62. Found:
C, 44.66; H, 3.95; N, 2.51%.
2.3. Physical measurements and instrumentation
UV–Vis spectra were recorded on a Perkin–Elmer
Lambda 19 spectrophotometer and steady state emis-
sion spectra on a SPEX Fluorolog-2 spectrophotometer.
Emission lifetime measurements were performed with a
Quanta Ray DCR-3 Nd-YAG laser (pulse output 355
nm, 8 ns). The decay signal was recorded by a R928
PMT (Hamamatsu), which was connected to a Tek-
tronix 2430 digital oscilloscope. Solutions for photo-
physical experiments were degassed by at least four
freeze–pump–thaw cycles.
2.4. X-ray crystallography
Suitable crystals were mounted on a glass capillary.
Data collection was carried out on a Bruker SMART
CCD diffractometer with Mo radiation at 293 K for 1
and 150 K for 2. A preliminary orientation matrix and
unit cell parameters were determined from 3 runs of 15
frames each, each frame corresponding to 0.3° scan in 15
s, followed by spot integration and least-square refine-
ment. Data were measured using an x scan of 0.3° per
frame for 20 s until a complete hemisphere had been
collected. Cell parameters were retrieved using SMART
[22] software and refined with SAINT [23] on all observed
reflections. Data reduction was performed with the
2. Experimental
2.1. General information
All reactions were performed under a nitrogen at-
mosphere and solvents for syntheses (analytical grade)
were used without further purification. NMR: Bruker
DPX 400 MHz NMR; deuterated solvents with the
usual standards. MS : Positive ion FAB mass spectra
were recorded on a Finnigan MAT95 mass spectrome-

B.-C. Tzeng et al. / Inorganica Chimica Acta 357 (2004) 1405–1410
1407
Table 1
Crystallographic data for 1 and 2
1
2
Empirical formula
Formula weight
Crystal system
Space group
C
35H30Au2N2P2S2
C40H40Au2N2P2S2
1068.73
monoclinic
P21/c
998.10
triclinic
Pbca
ꢀ
a (A)
11.2947(5)
21.7831(10)
27.3307(13)
90
11.9211(11)
19.6518(18)
8.2989(8)
90
ꢀ
b (A)
ꢀ
c (A)
a (°)
b (°)
c (°)
90
90
101.143(2)
90
3
ꢀ
V (A )
6724.3(5)
1.973
8
1907.5(3)
1.861
qcalc (g cmꢁ3
)
Z
2
79.06
l(Mo Ka) (cmꢁ1
F ð000Þ
)
89.64
472
273(2)
1028
150(1)
4378
T (K)
Observed reflections 5667
(Fo P 2rFo)
Refined parameters
Fig. 1. Molecular structure of 1. ORTEP diagram shows 50% proba-
ꢀ
bility ellipsoids. Selected bond lengths (A) and angles (°): Au(1)–S(1)
389
0.0297
0.0587
218
0.0235
0.0511
Ra
Rw
2.3044(13), Au(2)–S(2) 2.2948(14), Au(1)–P(1) 2.2613(12), Au(2)–P(2)
2.2705(13), Au(1)ꢀ ꢀ ꢀAu(2) 3.0478(3); P(1)–Au(1)–S(1) 175.48(4), P(2)–
Au(2)–S(2) 171.93(5).
b
P
P
a R ¼ kFoj ꢁ jFck= jFoj.
P
P
2
2
1=2
b wR2 ¼ f½ wðFo2 ꢁ Fc2Þ = ½wðFo2Þ ꢂg
.
SAINT software and corrected for Lorentz and polari-
zation effects. Absorption corrections were applied with
the program SADABS [24]. The structure was solved by
direct methods with the SHELX93 [25] program and re-
fined by full-matrix least-squares methods on F 2 with
SHEXLTL-PC V 5.03 [25]. All non-hydrogen atomic
positions were located in difference Fourier maps and
refined anisotropically. The hydrogen atoms were placed
in their geometrically generated positions. Detailed data
collection and refinement of the complexes are summa-
rized in Table 1.
3. Results and discussion
3.1. Description of crystal structure
Fig. 2. Molecular structure of 2. ORTEP diagram shows 50% proba-
ꢀ
bility ellipsoids. Selected bond lengths (A) and angles (°): Au(1)–S(1)
2.3062(9), Au(1)–P(1) 2.2468(9); P(1)–Au(1)–S(1) 169.93(3).
Perspective views of 1 and 2 are shown in Figs. 1 and
2, respectively. The Au(I) centers are all two-coordinate
and adopt an almost linear geometry with P–Au–S an-
gles ranging from 169.93(3) to 175.48(4)°. Au–P
phenyl groups, the intermolecular aurophilic interaction
is normally prevented in the solid state. However, there
is an additional intramolecular p ꢀ ꢀ ꢀ p interaction with a
ꢀ
[2.2468(9)–2.2705(13) A] and Au–S [2.2948(14)–
ꢀ
2.3062(9) A] distances all fall in a normal range
ꢀ
shortest distance of 3.49 A between the C atoms of the
[12a,12b,18,26].
As shown in Fig. 1, the crystal structure of 1 features
a dinuclear unit with an intramolecular aurophilic in-
roughly parallel phenyl rings of the neighboring diph-
enylphosphino moieties in 1. The distance of an intra-
ꢀ
molecular Auꢀ ꢀ ꢀS contact is 3.62 A suggestive of a weak
ꢀ
teraction at a distance of 3.0478(3) A, which is close to
interaction and the dihedral angle defined by Au(1)–
P(1)ꢀ ꢀ ꢀAu(2)–P(2) is 27.5°. Fig. 2 shows that there is a
twofold axis passing through the mid-point of the C(8)–
C(8A) bond for 2. The dpph adopts an anti conforma-
tion, so that the Au–SN moieties are well separated. A
close intermolecular gold(I)ꢀ ꢀ ꢀgold(I) contact is absent
ꢀ
the values of 3.0353(3)
A
in [Au2(dppm)(dtp)2]
[dtp ¼ S2P(p-C6H4–OCH3)(Oc-C5H9)ꢁ]
[26e]
3.0987(10) A in [dppm(Au(SSNH2))2], [26c] but slightly
and
ꢀ
ꢀ
shorter than the value of 3.351(2) A in [dppm(AuCl)2]
[21a]. Due to the steric effect of dppm bearing four

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B.-C. Tzeng et al. / Inorganica Chimica Acta 357 (2004) 1405–1410
Table 2
Spectroscopic and photophysical properties of 1 and 2
Compounds
kabs (nm) (e, dm3 molꢁ1cmꢁ1) in CH2Cl2
kem (nm)/s (ls) in
CH2Cl2
kem (nm)/s (ls) solid state (RT) (77 K)
1
2
268 (31 150)
324 (13 180)
274 (23 230)
312 (11 940)
400/1.1a
450/1.7
496/40.8
660/7.8
482/142.1
482/123.9
685/21.2
473
507/406.3
544
a Possibly an artifact.
in the solid state, and this was not originally expected
because of the flexible nature of dpph. Since the NS
moiety is not bulky and there is no other competing
force present in the crystal lattice (i.e., hydrogen bond-
ing), the absence of aurophilic interactions for 2 seems
to be only ascribed to crystal packing.
bands at ca. 320 nm of [8-QNS(AuPPh3)2] ꢀ BF4 (8-
QNS ¼ quinoline-8-thiolate) [10d] and ca. 326 nm of
[Au3(dpmp)2]3þ [27] are suggested to be related to the
1MC [metal-centered, 5d(dr*) ! 6p(pr)] transition
(aurophilicity), and thus the red-shift from 312 nm for 2
to 324 nm for 1 may be rationalized by the aurophilicity
present in 1.
3.2. UV–Vis absorption spectra
3.3. Emission spectra
Spectroscopic and photophysical data of 1 and 2 are
shown in Table 2. As shown in Fig. 3, the absorption
spectra of 1 and 2 measured in dichloromethane are very
similar and exhibit poorly vibronic-structured absorp-
tion bands at ca. 268 and 274 nm as well as broad ab-
sorption bands at ca. 324 and 312 nm, respectively. The
ca. 268 and 274 nm bands due to an intraligand tran-
sition of the diphosphine ligands are suggested based on
the work reported by Bruce and co-workers [18]. The ca.
324 and 312 nm absorption bands are tentatively as-
signed to an intraligand transition of the NS moieties in
character, since the free ligand shows the absorption
bands in a similar spectral region. However, a S ! Au
charge-transfer transition sitting under the intraligand
transition of NS is still possible. Notably, the absorption
The emission spectra of 1 and 2 measured in the solid
state at room temperature are shown in Fig. 4. At room
temperature, 1 displays a strong low-energy emission at
ca. 660 nm and a weak high-energy emission at ca. 496
nm upon photoexcitation at 355 nm, whereas 2 shows
only a strong high-energy emission at ca. 482 nm. Upon
cooling these samples to 77 K, 1 shows an energy con-
version process, where the high-energy emission (ca. 476
nm) increases in intensity while the low-energy one (ca.
685 nm) decreases. Similar emission properties have
been reported on the [(TPA)AuX] (X ¼ Cl, Br, I;
TPA ¼ 1,3,5-triaza-7-phosphaadamantane) [28] and
[N4P4(AuX)4] (X ¼ Cl, Br, I; N4P4 ¼ 1,4,8,11-tet-
ra(diphenylphosphinomethyl)-1,4,8,11-tetraazacyclote-
4x104
3x104
2x104
1x104
400
500
600
700
800
0
250
300
350
400
450
500
Wavelength / nm
Wavelength / nm
Fig. 4. The solid-state emission spectra of 1 (solid line) and 2 (dash
line) measured at room temperature with an excitation wavelength at
355 nm.
Fig. 3. The absorption spectra of 1 (solid line) and 2 (dash line)
measured in dichloromethane.

B.-C. Tzeng et al. / Inorganica Chimica Acta 357 (2004) 1405–1410
1409
tradecane) [10b] systems reported by Fackler and co-
workers and Che and co-workers, respectively. The
emission spectrum of 2 displays vibronic structures with
peak maximum at ca. 473, 507 and 544 nm upon cooling
to 77 K, and this progression with a spacing at 1300–
1400 cmꢁ1 is mostly due to the C@C or C@N stretching
mode of the NS ligand. The slight red-shift from 660
(RT) to 685 nm (77 K) may be explained by a temper-
ature effect, since cooling the crystals will cause a con-
comitant contraction in crystal lattices as well as a
strengthening in aurophilic interactions. In degassed
CH2Cl2, 2 shows a slight blue-shift with an emission
maximum at ca. 450 nm, whereas 1 displays only a weak
emission at ca. 400 nm. The ca. 450 nm emission for 2
with a similar energy compared to the related value of
ca. 482 nm in the solid state seems to have a similar
emission origin, assigned to a S ! Au charge-transfer
transition. It is noted that the ca. 400 nm emission for 1
is dramatically different from the ca. 496 and 660 nm
emissions in the solid state, and thus it is most likely
ascribed to a scattering effect or an artifact. Although
the non-emissive nature for 1 in solution, which is pos-
sibly due to solvent-induced quenching, prevents the
comparison between the solid state and solution be-
havior, the direct comparison between the emission en-
ergy and aurophilic interaction for 1 and 2 in the solid
state has been clearly made.
gold(I)ꢀ ꢀ ꢀgold(I) ones. Despite the intramolecular and
intermolecular gold(I)ꢀ ꢀ ꢀgold(I) interactions for
[(LAu)(AuPPhMe2)2]2, its solid-state emission at 520–
530 nm is comparable to that for [L(AuPPh3)3], without
any aurophilic interactions [10e]. Thus, 1 and 2 may
provide valuable examples to examine a close relationship
between the emission energy and aurophilic interaction.
4. Conclusion
Although it is becoming clear that the gold
(I)ꢀ ꢀ ꢀgold(I) bonding interaction is responsible for the
rich luminescence properties of gold(I) compounds,
there are only a handful of examples demonstrating a
close relationship between the emission energy and
aurophilic interaction for gold(I) thiolates [10d,19]. The
crystal structures of 1 and 2 have been determined by
crystallographic studies, and both feature a dinuclear
gold(I) thiolate. In the crystal structure of 1, the intra-
molecular aurophilic interaction at a distance of
ꢀ
3.0478(3) A is observed, whereas there is not any aur-
ophilic interaction present in the crystal lattices of 2. The
ca. 324 and 312 nm absorption bands for 1 and 2, re-
spectively, are tentatively assigned to an intraligand
transition of the NS moieties in character, but the slight
red-shift for the above absorption bands from 2 to 1 is
suggested to be contributed in part from the aurophilic
interaction. At room temperature 1 shows a low-energy
emission at ca. 660 nm as well as a very weak high-en-
ergy emission at ca. 496 nm in the solid state, whereas 2
shows only a strong high-energy one at ca. 482 nm.
Thus, the emission energy strongly dependent on the
Au(I)ꢀ ꢀ ꢀAu(I) interaction can be demonstrated in the
diphosphine digold(I) thiolates studied herein.
In a previous study [10d], 8-QNS(AuPPh3) shows a
very weak emission at ca. 477 nm in solution, whereas
excitation of
a dichloromethane solution of [8-
QNS(AuPPh3)2] ꢀ BF4 gives a very weak emission at
460nm and a strong and low-energy one with a long
lifetime of 26 ls at ca. 640 nm. The low-energy emission
is absent in 8-QNS(AuPPh3) and the gold(I)ꢀ ꢀ ꢀgold(I)
interaction is most probably responsible for the ca. 640
nm emission. The excited state for the ca. 640 nm emis-
sion is tentatively assigned to mostly come from the
metal-centered 5d(dr*) ! 6p(pr) excitation. When
compared to the 8-QNS system, 1 and 2 seem to have
similar excited state properties. Thus, the low-energy
emission at 660 nm is also suggested to mostly come from
the metal-centered 5d(dr*) ! 6p(pr) excitation. These
high-energy emissions in 1 and 2 most likely come from
the S ! Au excitation, with reference to previous studies
by Bruce and co-workers [18] on [Au(dppe)(pdt)Au] (515
nm; dppe ¼ 1,2-bis(diphenylphosphino)ethane, pdt ¼
1,3-propanedithiolate) and [Au(dppb) (pdt)Au] (510 nm;
dppb ¼ 1,4-bis(diphenylphosphino)butane).
Acknowledgements
We thank the National Science Council and National
Chung Cheng University of the Republic of China for
financial support (NSC 90-2113-M-194-028 and 91-
2113-M-194-019).
References
The relationship between the emission energy and
aurophilic interaction for gold(I) thiolates is so far still
unconclusive. In an earlier communication, Che and
co-workers [10e] reported a novel luminescent gold(I)
supermolecule with trithiocyanuric acid, [(LAu)(Au-
PPhMe2)2]2 (H3L ¼ trithiocyanuric acid), which has a
novel two-dimensional framework via intermolecular
gold(I)ꢀ ꢀ ꢀgold(I) interactions as well as intramolecular
€
[1] (a) P. Pyykko, Chem. Rev. 97 (1997) 597;
€
(b) P. Pyykko, Y. Zhao, Angew. Chem., Int. Ed. Engl. 34 (1995)
1894;
(c) P. Pyykko, J. Li, N. Runeberg, Chem. Phys. Lett. 218(1994)133;
€
€
(d) P. Pyykko, Y. Zhao, Chem. Phys. Lett. 177 (1991) 103;
(e) N. Rosch, A. Gorling, D.E. Ellis, H. Schmidbaur, Angew.
€
€
Chem., Int. Ed. Engl. 28 (1989) 1357;
(f) J.K. Burdett, O. Eisenstein, W.B. Schweizer, Inorg. Chem. 33
(1994) 3261.

1410
B.-C. Tzeng et al. / Inorganica Chimica Acta 357 (2004) 1405–1410
[2] (a) H. Schmidbaur, Gold Bull. 23 (1990) 11;
(b) H. Schmidbaur, F. Scherbaum, B. Huber, G. Muller, Angew.
Chem., Int. Ed. Engl. 27 (1988) 419.2;
[15] (a) C.F. Shaw III, M.T. Coffer, J. Klingbeil, C.K. Mirabelli, J.
Am. Chem. Soc. 110 (1988) 729;
€
(b) M.T. Coffer, C.F. Shaw III, M.K. Eidsness, J.W. Watkins II,
R.C. Elder, Inorg. Chem. 25 (1986) 333;
(c) H. Schmidbaur, Chem. Soc. Rev. 24 (1995) 391;
(d) H. Schmidbaur, Interdiscipl. Sci. Rev. 17 (1992) 213;
(e) H. Schmidbaur, Gold Bull. 33 (2000) 1;
(f) H. Schmidbaur (Ed.), Gold-Progress in Chemistry, Biochem-
istry and Technology, Wiley, Chichester, 1999.
[3] (a) J.C. Vickery, M.M. Olmstead, E.Y. Fung, A.L. Balch, Angew.
Chem., Int. Ed. Engl. 36 (1997) 1179;
(c) A.A. Isab, P.J. Sadler, J. Chem. Soc., Dalton Trans. (1982)
135.
[16] W.S. Rapson, Gold Usage, Academic Press, London, 1978.
[17] C.D. Bain, G.M. Whitesides, Angew. Chem., Int. Ed. Engl. 28
(1989) 506.
[18] (a) R. Narayanaswamy, M.A. Young, E. Parkhurst, M. Ouellette,
M.E. Kerr, D.M. Ho, R.C. Elder, A.E. Bruce, M.R.M. Bruce,
Inorg. Chem. 32 (1993) 2506;
(b) J.C. Vickery, A.L. Balch, Inorg. Chem. 36 (1997) 5978;
(c) P.M.V. Calcar, M.M. Olmstead, A.L. Balch, Inorg. Chem. 36
(1997) 5231;
(b) W.B. Jones, J. Yuan, R. Narayanaswamy, M.A. Young, R.C.
Elder, A.E. Bruce, M.R.M. Bruce, Inorg. Chem. 34 (1995) 1996.
[19] J.M. Forward, D. Bohmann, J.P. Fackler Jr., R.J. Staples, Inorg.
Chem. 34 (1995) 6330.
(d) P.M.V. Calcar, M.M. Olmstead, A.L. Balch, J. Chem. Soc.,
Chem. Commun. (1995) 1773.
[4] (a) J.P. Fackler Jr., Polyhedron 16 (1997) 1;
(b) J.P. Fackler Jr., Inorg. Chem. 41 (2002) 6959.
[5] (a) R.J. Puddephatt, Coord. Chem. Rev. 216–217 (2001)
313;
ꢁ
ꢂ
ꢂ
[20] (a) R. Uson, A. Laguna, M. Laguna, J. Jimenez, M.P. Gomez, A.
Sainz, P.G. Jones, J. Chem. Soc., Dalton Trans. (1990) 3457;
(b) G. Jia, R.J. Puddephatt, J.J. Vittal, Polyhedron 11 (1992) 2009;
(c) P.D. Cookson, E.R.T. Tiekink, J. Chem. Soc., Dalton Trans.
(1993) 259;
(b) R.J. Puddephatt, Chem. Commun. (1998) 1055;
(c) R.J. Puddephatt, The Chemistry of Gold, Elsevier, Amster-
dam, 1978.
(d) J. Vicente, M.T. Chicote, P. Gonzalez-Herrero, P.G. Jones, J.
Chem. Soc., Dalton Trans. (1994) 3183;
[6] (a) M. Contel, J. Garrido, M.C. Gimeno, P.G. Jones, A. Laguna,
M. Laguna, Organometallics 15 (1996) 4939;
(b) M.C. Gimeno, A. Laguna, Chem. Rev. 97 (1997)
511.
ꢂ
(e) M. Bardajı, N.G. Connelly, M.C. Gimeno, P.G. Jones, A.
Laguna, M. Laguna, J. Chem. Soc., Dalton Trans. (1995) 2245;
(f) L. Hao, R.J. Lachicotte, H.J. Gysling, R. Eisenberg, Inorg.
Chem. 38 (1999) 4616;
[7] (a) D.M.P. Mingos, J. Yau, S. Menzer, D.J. Williams, Angew.
Chem., Int. Ed. Engl. 34 (1995) 1894;
(g) F. Canales, M.C. Gimeno, P.G. Jones, A. Laguna, C. Sarroca,
Inorg. Chem. 36 (1997) 5206.
(b) D.M.P. Mingos, J. Chem. Soc., Dalton Trans. (1996) 561.
[8] (a) P.G. Jones, B. Ahrens, New J. Chem. (1998) 104;
(b) Chem. Ber./Recueil 130 (1997) 1813;
[21] (a) H. Schmidbaur, A. Wohlleben, F. Wagner, O. Orama, G.
Huttner, Chem. Ber. 110 (1977) 1748;
(c) J. Vicente, M.-T. Chicote, M.-D. Abrisqueta, R. Guerrero,
P.G. Jones, Angew. Chem., Int. Ed. Engl. 36 (1997) 1203.
[9] (a) V.W.-W. Yam, K.K.-W. Lo, Chem. Soc. Rev. 28 (1999)
323;
(b) D.S. Eggleston, J.V. McArdle, G.E. Zuber, J. Chem. Soc.,
Dalton Trans. (1987) 677.
[22] SMART V 4.043 Software for the CCD Detector System, Siemens
Analytical Instruments Division, Madison, WI, 1995.
[23] SAINT V 4.035 Software for the CCD Detector System, Siemens
Analytical Instruments Division, Madison, WI, 1995.
[24] G.M. Sheldrick, SHELXL-93, Program for the Refinement of
Crystal Structures, University of Gottingen, Gottingen, Germany,
1993.
(b) V.W.-W. Yam, E.C.-C. Cheng, Angew. Chem., Int. Ed. Engl.
39 (2000) 4240;
(c) V.W.-W. Yam, E.C.-C. Cheng, Gold Bull. 34 (2001) 20.
[10] (a) B.-C. Tzeng, W.-C. Lo, C.-M. Che, S.-M. Peng, Chem.
Commun. (1996) 181;
(b) B.-C. Tzeng, K.-K. Cheung, C.-M. Che, Chem. Commun.
(1996) 1681;
[25] SHELXTL 5.03 (PC-Version), Program Library for Structure
Solution and Molecular Graphics, Siemens Analytical Instru-
ments Division, Madison, WI, 1995.
(c) B.-C. Tzeng, C.-M. Che, S.-M. Peng, J. Chem. Soc., Dalton
Trans. (1996) 1769;
[26] (a) V.W.W. Yam, W.K. Lee, J. Chem. Soc., Dalton Trans. (1993)
2097;
(d) B.-C. Tzeng, C.-K. Chan, K.-K. Cheung, C.-M. Che, S.-M.
Peng, Chem. Commun. (1997) 135;
(b) Z. Assefa, B.G. McBurnett, R.J. Staples, J.P. Fackler Jr., B.
Assmann, K. Angermaier, H. Schmidbaur, Inorg. Chem. 34 (1995)
7518;
(e) B.-C. Tzeng, C.-M. Che, S.-M. Peng, Chem. Commun. (1997)
1771.
[11] A. Bondi, J. Phys. Chem. 68 (1964) 441.
[12] (a) C.-M. Che, H.-L. Kwong, V.W.-W. Yam, K.-C. Cho, J. Chem.
Soc., Chem. Commun. (1989) 885;
(c) B.-C. Tzeng, A. Schier, H. Schmidbaur, Inorg. Chem. 38
(1999) 3978;
(d) M.A. Rawashdeh-Omary, M.A. Omary, H.H. Patterson, J.P.
Fackler Jr., J. Am. Chem. Soc. 123 (2001) 11237;
(e) A. Maspero, I. Kani, A.A. Mohamed, M.A. Omary, R.J.
Staples, J.P. Fackler Jr., Inorg. Chem. (2003), ASAP Article;
(f) H.-K. Yip, A. Schier, J. Riede, H. Schmidbaur, J. Chem. Soc.,
Dalton Trans. (1994) 2333.
(b) C.M. Che, H.L. Kwong, W.W. Yam, T.F. Lai, C.M. Che, J.
Chem. Soc., Dalton Trans. (1990) 3747;
(c) C. King, J.C. Wang, M.N.I. Khan, J.P. Fackler Jr., Inorg.
Chem. 28 (1989) 2145;
(d) L.H. Gade, Angew. Chem., Int. Ed. Engl. 36 (1997)
1171;
[27] D. Li, C.-M. Che, S.-M. Peng, S.-T. Liu, Z.-Y. Zhou, T.C.-W.
Mak, J. Chem. Soc., Dalton Trans. (1993) 189.
[28] (a) Z. Assefa, B.G. McBurnett, R.J. Staples, J.P. Fackler Jr., B.
Assmann, K. Angermaier, H. Schmidbaur, Inorg. Chem. 34 (1995)
75;
(e) W.-F. Fu, K.-C. Chan, V.M. Miskowski, C.-M. Che, Angew.
Chem., Int. Ed. 38 (1999) 2783.
[13] M.A. Mansour, W.B. Connick, R.J. Lachicotte, H.J. Gysling, R.
Eisenberg, J. Am. Chem. Soc. 120 (1998) 1329.
[14] C.L. Exstrom, J.R. Sowa Jr., C.A. Daws, D. Janzen, G.A. Moore,
F.F. Stewart, K.R. Mann, Chem. Mater. 7 (1995) 15.
(b) Z. Assefa, B.G. McBurnett, R.J. Staples, J.P. Fackler Jr.,
Inorg. Chem. 34 (1995) 4965.