Luminescent homo- and heteropolynuclear gold complexes stabilized by a unique acetylide fragment

Article abstract of DOI:10.1021/om200397t

In this paper we describe the reactivity of the gold acetylide derivatives [Au(C≡CR)(PPh₃)] (R = Ph, 2-py). Reactions of these complexes with fragments of the type [M(PPh₃)₂]⁺ (M = Au, Ag, Cu) afford a series of novel discrete molecules stabilized not only by interactions with the triple bond but also by the formation of strong metal-gold interactions. The crystal structures of the gold-gold and gold-silver species confirm their similar behavior, while X-ray diffraction establishes a different arrangement for the copper complex with pyridine acetylide as a consequence of the coordination of this metal center to the nitrogen atom of pyridine and to the carbons of the alkyne. The luminescent properties of the complexes were also studied.

Full text of DOI:10.1021/om200397t

ARTICLE
pubs.acs.org/Organometallics
Luminescent Homo- and Heteropolynuclear Gold Complexes
Stabilized by a Unique Acetylide Fragment
||
M. Carmen Blanco,†, Jꢀessica Cꢀamara,† M. Concepciꢀon Gimeno,† Peter G. Jones,§ Antonio Laguna,*,†
Josꢀe M. Lꢀopez-de-Luzuriaga,‡ M. Elena Olmos,‡ and M. Dolores Villacampa†
†Departamento de Química Inorgꢀanica, Instituto de Síntesis Química y Catꢀalisis Homogꢀenea (ISQCH), Universidad de Zaragoza-CSIC,
C/Pedro Cerbuna 12, 50.009 Zaragoza, Spain
‡Departamento de Química, Universidad de La Rioja, Grupo de Síntesis Química de La Rioja, UA-CSIC, Madre de Dios 51,
26004 Logro~no, Spain
§Institut f€ur Anorganische und Analytische Chemie der Technischen Universit€at, Postfach 3329, 38023 Braunschweig, Germany
Centro Universitario de la Defensa, Academia General Militar, Ctra. de Huesca s/n. 50.090 Zaragoza, Spain
S Supporting Information
b
ABSTRACT: In this paper we describe the reactivity of the gold acetylide derivatives
[Au(CtCR)(PPh3)] (R = Ph, 2-py). Reactions of these complexes with fragments of
the type [M(PPh3)2]+ (M = Au, Ag, Cu) afford a series of novel discrete molecules
stabilized not only by interactions with the triple bond but also by the formation of
strong metalꢀgold interactions. The crystal structures of the goldꢀgold and goldꢀ
silver species confirm their similar behavior, while X-ray diffraction establishes a
different arrangement for the copper complex with pyridine acetylide as a consequence
of the coordination of this metal center to the nitrogen atom of pyridine and to the
carbons of the alkyne. The luminescent properties of the complexes were also studied.
’ INTRODUCTION
alkyne coupling processes, heteroatomꢀhydrogen bond additions,
hydrogenations, CspꢀH bond functionalizations, etc.9 Furthermore,
gold is an excellent catalyst: for example, in the hydrochlorination of
acetylene to give vinyl chloride, a very important industrial process.
This type of complex could therefore be suitable for the study of
alkyneꢀmetal bonds and provide relevant information about reaction
mechanisms.
Moreover, one of the main goals in modern chemistry is the
understanding of the relation between the properties of matter and
the specific structure, and new potent instrumental methods are a
useful tool for this. However, it was not easy to find reports where
synthesis, reactivity, crystal structures, and luminescent properties
had been related in a thorough study.
In order to study the reactivity of neutral gold acetylide deriva-
tives, we tested the reactions of the compounds [Au(CtCR)-
(PPh3)] (R = Ph, 2-py) with the cationic species of group 11
metals [M(PPh3)2]+. The substrates thus obtained showed not
only novel structural properties but also interesting luminescent
behavior. Whereas the gold and silver structures are very similar,
Part of the fascination of gold(I) chemistry is due to the frequent
formation of intramolecular goldꢀgold interactions (aurophilicity)1
and the tendency to adopt linear coordination.2 For gold(I) alkynyl
complexes, the combined linear geometries together with the stiff-
ness of the alkynyl groups make these derivatives suitable as building
blocks for polymers3 or can provide materials that show unusual
nonlinear optical or photoemission properties involved in the design
of sensors or devices.4 Thus, the photophysical properties of gold
have been profusely studied in the past few years because of their
versatility and the development of related technological applications.5
The reactivity of alkynes toward transition metals has been the
subject of many studies, because of the versatility in the bonding
properties of the acetylide group.6 In the case of gold, the most
studied reactivity has related to bis(acetylide) gold substrates or
dimeric species formed by gold acetylide fragments and diphosphine
ligands. The great majority of these compounds are polymeric spe-
cies in which gold is π-coordinated at least through two alkyne
fragments, providing very symmetrical structures that show limited
solubility in organic solvents.7 Mononuclear systems are less com-
mon, and examples of discrete molecules are scarce.8 There is also
considerable interest in the isolation of coinage metal acetylide com-
plexes consisting of discrete molecules, because they are key com-
pounds in many transformations involving alkynes: cycloadditions,
Special Issue: F. Gordon A. Stone Commemorative Issue
Received: May 13, 2011
Published: July 05, 2011
r
2011 American Chemical Society
2597
dx.doi.org/10.1021/om200397t Organometallics 2012, 31, 2597–2605
|

Organometallics
ARTICLE
Scheme 1a
Scheme 2a
a Legend: (i) [Au(acac)(PPh3)]; (ii) [Au(PPh3)2]OTf; (iii) [Ag(PPh3)2]-
OTf; (iv) [Cu(O2NO)(PPh3)2].
a Legend: (i) [Au(acac)(PPh3)]; (ii) [Au(PPh3)2]OTf; (iii) [Ag(PPh3)2]-
OTf; (iv) [Cu(O2NO)(PPh3)2].
into two, arising from the two types of phosphorus atoms that are
assigned to PPh3 bonded to the gold center σ-coordinated to the
alkyne (PPh3AuCtC) at δ 41.0 (2), 39.9 (3), and 42.0 ppm (4)
and another broad signal arising from the fragments M(PPh3)2.
The latter appear as singlets for complexes 2 and 4 (δ 43.4 and
ꢀ2.3 ppm, respectively) but in the case of the goldꢀsilver
derivative the signal is split into two doublets because of the
coupling of the phosphorus with the magnetically active 107Ag
copper showed notable differences as a consequence of the participa-
tion of the pyridyl group in the coordination sphere of the metal.
Here we report new examples of homo- and heterometallic
gold acetylide compounds where the π-bonded metal is stabi-
lized by a unique metalꢀalkyne interaction and strong metallo-
philic interactions. Furthermore, we have been able to determine
their crystal structures by X-ray diffraction in order to understand
better their luminescent behavior.
and 109Ag isotopes of the silver center (δ 8.8 ppm (3)). The 19
F
NMR spectra of 2 and 3 show the resonance from the fluorine
atoms of the triflate anion (δ ꢀ78.0 (2), ꢀ77.9 ppm (3)). Their
1H NMR spectra only show resonances attributed to aromatic
protons from the triphenylphosphine ligands or from the aryl
moiety of the acetylide group. None of the molecular peaks are
detected in the mass spectra; however, several peaks correspond-
ing to various fragments are observed (see the Experimental
Section). Most representative peaks are those arising from the
loss of a PPh3 ligand [AuM(CtCPh)(PPh3)2]+ at m/z 1019
(17%, 2), 931 (8%, 3), and 885 (10%, 4). Crystals of complexes 2
and 3 suitable for X-ray diffraction analyses were grown by slow
diffusion of hexane into a dichloromethane solution of the
complex (see Crystal Structure Analyses).
With these examples we can conclude that gold, silver, and
copper present a similar behavior with the alkyne triple bond.
In order to study the effect of the presence of other groups
with donor properties in the same gold fragment, we decided to
study similar reactions toward a pyridine derivative. Thus, by a
similar methodology used for the compound 1, we prepared
[Au(CtCpy)PPh3] (5) by reaction of 2-pyridylacetylene and
[Au(acac)PPh3] in dichloromethane. The reaction of this pro-
duct with [Au(PPh3)2]OTf or [Ag(PPh3)2]OTf leads to the
formation of [AuM(CtCpy)(PPh3)3]OTf (M = Au (6), Ag
(7)) (see Scheme 2). These compounds are obtained as air- and
moisture-stable white solids at room temperature and they are
soluble in chlorinated solvents but insoluble in hexane. Their IR
spectra show the characteristic bands of the trifluoromethylsul-
fonate anion. Again the alkyne absorption does not appear in the
IR spectra of the new compounds, due to the participation of this
electron density in the bonds to the second metallic center. Their
31P{1H} NMR spectra show two resonances corresponding to
the two different types of PPh3 groups present in the molecules.
’ RESULTS
The neutral derivative [Au(CtCPh)(PPh3)] (1) was pre-
pared from phenylacetylene and [Au(acac)PPh3] in equimolar
amounts (Scheme 1), making use of the excellent properties as
deprotonating/aurating agent of the latter,10 rather than the
other preparative methods previously reported.11
In order to study the reactivity of this unsaturated bond
toward cationic species of group 11 metals, we decided to test
the reactions of 1 with the species [M(PPh3)2]X (M = Au (2),
Ag (3), Cu (4); X = OTf (trifluoromethylsulfonate; 2, 3), NO3 (4)),
which lead to the formation of the respective dinuclear deriva-
tives [AuM(CtCPh)(PPh3)3]X (Scheme 1). Complexes 2ꢀ4
are obtained as stable white solids, soluble in most common
solvents but insoluble in diethyl ether and hexane. Their analy-
tical and spectroscopic data are in accordance with the proposed
stoichiometries.
Their IR spectra show bands assignable to triflate (2, 3) or
nitrate (4) at ν 1264 (vs, br) and 1147 cmꢀ1 (m, br) (2) and at
1264 (vs, br) and 1146 cmꢀ1 (m, br) (3) or at 1071 (w), 998
(m), and 691 cmꢀ1 (vs) (4). Additionally, it is noteworthy that
the absorption arising from the CtC group σ-bonded to gold at
ν 2113 cmꢀ1 (w) in the starting material (1) does not appear in
these three derivatives. That seems to indicate that the triple
bond has been modified by the interaction with the newly
incorporated second metal center.
The 31P{1H} NMR spectra of the complexes show broad
signals at room temperature. We therefore decided to register the
NMR measurements at low temperature. Thus, signals were split
2598
dx.doi.org/10.1021/om200397t |Organometallics 2012, 31, 2597–2605

Organometallics
ARTICLE
In order to increase the resolution of the spectra, the temperature
of measurement was lowered to 223 K. While for the homo-
nuclear derivative two signals in an approximate ratio 2:1 appear
at 44.4 (Au(PPh3)2) and 41.5 ppm (AuꢀP terminal), the
spectrum of the mixed goldꢀsilver derivative shows a broad
signal related to the phosphorus atom coordinated to gold (40.0
ppm) and two doublets at higher field as a consequence of the
AgꢀP coupling (8.8 ppm). Their 19F NMR spectra show the
presence of triflate, and only phenyl or pyridyl protons are
1
observed in the H NMR spectra of 6 and 7. In the mass
spectrum (MALDI) of 6 the molecular peak is detected at m/z
1282 (2%). For the silver compound, several peaks correspond-
ing to various fragments are observed (see the Experimental
Section). Layering a chloroform solution of complex 7 with
hexane afforded crystals of this derivative which were suitable for
X-ray diffraction studies (see Crystal Structure Analyses).
The tendency of copper to coordinate to nitrogen donor
ligands is well-known.12 Thus, in order to compare the relative
reactivities of gold, silver, and copper we tested the reaction
between compound 5 and [Cu(O2NO)(PPh3)2] in a 1:1 molar
ratio. In this case the final color of the solution reaction is yellow,
in contrast to the goldꢀgold and goldꢀsilver solutions, which
are colorless. Thus, compound 8, which matches the formula
[AuCu(CtCpy)(PPh3)2](NO3), is obtained as a yellow solid,
stable to air and moisture and soluble in chlorinated solvents and
acetone, but insoluble in hexane. In this case a major attraction
between copper and nitrogen donor ligands causes the inter-
change of PPh3 by a Cuꢀpyridine interaction (Scheme 2).
Unlike the case for the IR spectra registered for the AuꢀAu
and AuꢀAg compounds, an analysis of the IR spectra of the
goldꢀcopper compound shows the stretching band CtC at
2112 cmꢀ1, revealing a different behavior of copper from the
heavier metals in the group. The broad signals found in the
31P{1H} NMR spectrum of 8 in CDCl3 at 223 K are assigned to
the phosphorus atom coordinated to gold at δ 40.9 ppm and at
high field to the fragment CuꢀPPh3 (δ ꢀ0.4 ppm). Its 1H NMR
spectrum only displays the resonances arising from phenyl or
pyridine groups. The molecular cation was not detected in its
mass spectrum; however, several revealing fragments were found,
such as the peaks due to [AuCu(CtCpy)(PPh3)2]+ (m/z 886,
25%) or [Au2Cu(CtCpy)2(PPh3)2]+ (m/z 1185, 5%).
Figure 1. Structure of the cation of complex 2. Hydrogen atoms have
been omitted for clarity.
Figure 2. Structure of the cation of complex 3. Hydrogen atoms have
been omitted for clarity.
Layering a chloroform solution of complex 8 with hexane
afforded crystals of the copper compound that were suitable for
X-ray diffraction studies (see Crystal Structure Analyses).
Crystal Structure Analyses. The crystal structures of the
mixed goldꢀgold and goldꢀsilver derivatives 2, 3, and 7 have
been determined by X-ray diffraction (Figures 1ꢀ3). Selected
bond lengths and angles are collected in Table 2. The molecules of
these complexes have a similar array of atoms, as can be seen in
Figures 1ꢀ3 with the metal of one [Au(PPh3)2]+ (2) or [Ag-
(PPh3)2]+ fragment (3, 7) bonded to both the acetylene gold atom
and one carbon (CR) atom of the acetylene group (distances to the
Cβ atom are appreciably longer). The short intramolecular goldꢀ
gold (2.9165(5) Å in 2) and goldꢀsilver distances (2.8600(2) Å in
3 and 2.9643(2) Å in 7) indicate normal d10ꢀd10 interactions
between the metals. Complexes 2 and 7 are isostructural, with
closely similar unit cells in the orthorhombic space group Pna21
(experimental data shown in Table 1); complex 3 crystallizes in the
triclinic system, space group P1. The angles PꢀAuꢀCR (from
176.69(8)° to 178.3(2)°) are only slightly distorted from linearity
by the coordination of the [M(PPh3)2]+ fragment to the gold(I)
acetylene complex.
The CtC bond distances found in the complexes (range from
1.186(8) Å in 2 to 1.217(2) Å in 7) are normal for a carbonꢀ
carbon triple bond and show no significant differences from
CtC bond distances present in the corresponding starting materials
[Au(CtCPh)(PPh3)]13 (1) (1.16(2), 1.18(2) Å; two molecules
connected through a weak Au Au interaction) or [Au(CtCpy)-
3 3 3
(PPh3)]14 (5) (1.21(1) Å ꢁ 2; two independent molecules in each
asymmetric unit without an intermolecular metalꢀmetal bond). In
addition, the AuꢀCR bond distances of the phenylacetylene gold(I)
group (ranging from 1.997(3) Å in 7 to 2.032(6) Å in 2) are similar
to those exhibited by the corresponding starting materials [Au(Ct
CPh)(PPh3)] (1.97(2), 2.02(2) Å) and [Au(CtCpy)(PPh3)]
(1.95(1), 1.97(1) Å).
The acetylene ligand in each compound can be seen as an asym-
metric bridge between the two metals, with one of the MꢀCR
distances being much shorter than the other (the asymmetric μ-
η1:η1 mode is probably forced by the metallophilic interaction). The
longer distances, which correspond to the metal of the [M(PPh3)2]+
fragment, are 2.602(5) Å in 2 (AuꢀCR bond), 2.463(3) Å in 3, and
2599
dx.doi.org/10.1021/om200397t |Organometallics 2012, 31, 2597–2605

Organometallics
ARTICLE
2.482(3) Å in 7 (AgꢀCR bond); the last two compare well with the
AgꢀCR distances observed in the complex [Ag{(AuPTo3)2{μ-
copper atoms. Each copper atom is bonded symmetrically to
the acetylene group in a η2 fashion, with CuꢀC distances ranging
from 2.027(7) to 2.108(8) Å. These are similar to those found in
the complex [Cu4(μ-η1:η2-CtC)(μ-dppm)4](BF4)2 (2.12(1)
and 2.13(1) Å).16 The coordination of the metal to the acetylene
moiety produces only a minimal lengthening of the carbonꢀ
carbon bond distance, which goes from 1.21(1) Å in the starting
material14 to 1.222(11) or 1.231(11) Å in the goldꢀcopper
derivative. In contrast to the other complexes described in this
Ar(CtC)2}}2]ClO4 2CHCl3 (To = C6H4Me-4, Ar = C6Me4)15
3
in which one silver atom is bonded to four AuCtC fragments in a
similar asymmetric mode. Furthermore, the distances M Cβ are
3 3 3
notably longer and range from 2.817 Å in 7 to 3.133 Å in 2.
The crystal structure of complex 8 has also been established by
X-ray diffraction, and the molecule is shown in Figure 4. Selected
bond lengths and angles are collected in Table 2. The compound
is a dimer with two Ph3PꢀAuꢀCtCpy units bridging two
paper, there are no short Au Cu contacts: the distances are
3 3 3
3.480 and 3.540 Å, which are too long to involve any bonding
interaction. The nature of the copper bond to the gold acetylene
compounds is different from that shown by the silver and gold
atoms. The copper centers are four-coordinated to one phos-
phine ligand, to both carbon atoms of the acetylene, and to the
nitrogen atom of the pyridine group; the geometry is far from an
ideal tetrahedron, with dihedral angles between the planes
N(2)Cu(1)P(3) and C(1)Cu(1)C(2) of 17.2° and N(1)Cu-
(2)P(4) and C(41)Cu(2)C(42) of 0.2°, and thus can be better
described as trigonal, with the midpoint of the carbonꢀcarbon
triple bond as one ligand. Also, the copper atoms lie only 0.195
and 0.002 Å out of the plane formed by their four donor atoms.
The gold centers are linearly coordinated, and the bond lengths
and angles are normal.
Optical Properties. The absorption data of complexes 2ꢀ8
are summarized in Table 3.
The electronic absorption spectra of 2ꢀ4 in dichloromethane
at 298 K show very intense bands at 233ꢀ240 nm (ε = 13 560,
17 109, 13 804 molꢀ1 L cmꢀ1, respectively) and a shoulder at
270 nm with tails extending to ca. 320 nm (see Figure 5). The
assignation of the absorptions is made by comparison with those
Figure 3. Structure of the cation of complex 7. Hydrogen atoms have
been omitted for clarity.
Table 1. X-ray Data for Complexes 2, 3, 7, and 8
2
3 2CH2Cl2
7
8 5CHCl3
3
3
formula
Mr
C63H50Au2F3O3P3S
1430.93
C65H54AgAuF3O3P3SCl4
1511.69
C62H49AgAuF3NO3P3S
1342.83
C91H73Au2Cl15Cu2N4O6P4
2495.18
habit/color
cryst size (mm)
cryst syst
space group
cell constants
a (Å)
prism/colorless
0.42 ꢁ 0.23 ꢁ 0.11
orthorhombic
Pna21
prism/colorless
0.25 ꢁ 0.12 ꢁ 0.12
triclinic
Tablet/colorless
0.35 ꢁ 0.35 ꢁ 0.10
orthorhombic
Pna21
needle/colorless
0.20 ꢁ 0.07 ꢁ 0.06
triclinic
P1
P1
20.097(4)
17.631(4)
15.462(3)
11.3194(3)
14.9455(3)
18.3582(5)
94.351(1)
94.243(1)
93.381(1)
2
1.629
3.035
1500
19.8613(3)
17.5402(3)
15.5700(3)
14.822(3)
15.542(3)
22.752(5)
88.03(3)
86.85(3)
66.90(3)
2
1.722
4.011
2452
b (Å)
c (Å)
R (deg)
β (deg)
γ (deg)
Z
4
4
D
exptl (Mg mꢀ3
)
1.735
5.532
2792
ꢀ173
51
1.644
3.247
2664
ꢀ173
59
μ (mmꢀ1
F(000)
)
T (°C)
ꢀ173
ꢀ173
2θmax (deg)
no. of rflns
measd
indep
transmissions
Rint
no. of params
no. of restraints
Rw(F2, all rflns)
R(I > 2σ(I))
S
55
51
77 283
10 149
0.2047, 0.5813
0.0268
677
54 081
14 051
0.5783ꢀ0.5136
0.0480
730
236 891
15 010
0.59915ꢀ1.00000
0.0562
677
71 486
17 848
0.5009ꢀ0.7948
0.062
1154
211
0.157
0.060
1.025
19
0
651
0.0875
0.0318
1.036
0.0580
0.0261
1.035
0.0577
0.0262
0.995
Flack param
0.224(7)
1.893
0.585(3)
3.139
max ΔF (e Åꢀ3
)
1.728
4.65
2600
dx.doi.org/10.1021/om200397t |Organometallics 2012, 31, 2597–2605

Organometallics
ARTICLE
Table 2. Selected Bond Lengths (Å) and Angles (deg) for
Complexes 2, 3, 7, and 8
Complex 2
Au(1)ꢀC(1)
Au(1)ꢀP(1)
Au(1)ꢀAu(2)
Au(2)ꢀP(2)
2.032(6)
Au(2)ꢀP(3)
Au(2)ꢀC(1)
C(1)ꢀC(2)
2.303(2)
2.602(5)
1.186(8)
2.2838(17)
2.9165(5)
2.281(2)
C(1)ꢀAu(1)ꢀP(1)
C(1)ꢀAu(1)ꢀAu(2)
P(1)ꢀAu(1)ꢀAu(2)
P(2)ꢀAu(2)ꢀP(3)
P(2)ꢀAu(2)ꢀC(1)
178.2(2)
60.33(15)
121.34(5)
147.92(7)
111.0(2)
P(3)ꢀAu(2)ꢀC(1)
P(2)ꢀAu(2)ꢀAu(1)
P(3)ꢀAu(2)ꢀAu(1)
C(1)ꢀAu(2)ꢀAu(1)
100.3(2)
105.93(6)
101.57(6)
42.75(13)
Complex 3
AuꢀC(8)
AuꢀP(1)
AuꢀAg
2.019(3)
AgꢀP(2)
2.4408(7)
2.463(3)
1.203(4)
2.2780(7)
2.8600(2)
2.4344(7)
AgꢀC(8)
C(7)ꢀC(8)
Figure 4. Structure of the cation of complex 8. Hydrogen atoms have
been omitted for clarity.
AgꢀP(3)
C(8)ꢀAuꢀP(1)
P(3)ꢀAgꢀP(2)
P(3)ꢀAgꢀC(8)
P(2)ꢀAgꢀC(8)
176.69(8)
P(3)ꢀAgꢀAu
P(2)ꢀAgꢀAu
C(8)ꢀAgꢀAu
114.194(17)
109.459(17)
43.78(6)
131.67(2)
114.10(6)
111.43(7)
Table 3. UVꢀVisible Data for Complexes 2ꢀ8 in Dichlor-
omethane (5 ꢁ 10ꢀ5 M)
Complex 7
compd
λmax (nm) [ε (dm3 molꢀ1 cmꢀ1)]
AuꢀC(1)
AuꢀP(1)
AuꢀAg
1.997(3)
AgꢀP(3)
AgꢀC(1)
AgꢀC(2)
C(1)ꢀC(2)
P(3)ꢀAgꢀC(2)
C(1)ꢀAgꢀC(2)
P(2)ꢀAgꢀAu
P(3)ꢀAgꢀAu
C(1)ꢀAgꢀAu
C(2)ꢀAgꢀAu
2.4171(13)
2.482(3)
2.817(2)
1.217(4)
2.2780(7)
2.9643(2)
2.4075(13)
2
3
4
5
6
7
8
233 [13 560], 270 [6107], 280 [4993]
240 [17 109], 270 [16 300]
230 [13 804], 270 [9620]
220 [12 595], 275 [24 185]
230 [13 867], 290 [3604]
230 [15 004]
AgꢀP(2)
C(1)ꢀAuꢀP(1)
C(1)ꢀAuꢀAg
P(1)ꢀAu--Ag
178.3(2)
56.05(8)
105.48(13)
25.57(8)
105.78(3)
103.10(3)
41.86(6)
67.39(5)
123.87(2)
140.19(3)
113.66(17)
106.14(18)
110.60(13)
P(2)ꢀAgꢀP(3)
P(2)ꢀAgꢀC(1)
P(3)ꢀAgꢀC(1)
P(2)ꢀAgꢀC(2)
230 [20 234], 350 [1217]
Complex 8
Au(1)ꢀC(1)
Au(1)ꢀP(1)
C(1)ꢀC(2)
2.002(8)
2.272(2)
1.222(11)
2.108(8)
2.068(8)
1.984(7)
1.231(11)
2.011(8)
C(41)ꢀCu(2)
C(42)ꢀCu(2)
C(43)ꢀN(2)
N(2)ꢀCu(1)
Au(2)ꢀP(2)
Cu(1)ꢀP(3)
Cu(2)ꢀP(4)
2.065(8)
2.027(7)
1.361(10)
2.027(6)
2.281(2)
2.251(2)
2.255(2)
C(1)ꢀCu(1)
C(2)ꢀCu(1)
N(1)ꢀCu(2)
C(41)ꢀC(42)
C(41)ꢀAu(2)
C(1)ꢀAu(1)ꢀP(1)
172.6(2)
115.7(4)
C(2)ꢀCu(1)ꢀP(3)
C(1)ꢀCu(1)ꢀP(3)
N(1)ꢀCu(2)ꢀC(42)
N(1)ꢀCu(2)ꢀC(41)
C(42)ꢀCu(2)ꢀC(41)
N(1)ꢀCu(2)ꢀP(4)
C(42)ꢀCu(2)ꢀP(4)
C(41)ꢀCu(2)ꢀP(4)
146.5(2)
112.5(2)
104.4(3)
139.4(3)
35.0(3)
106.29(19)
149.3(2)
114.3(2)
Au(1)ꢀC(1)ꢀCu(1)
Au(2)ꢀC(41)ꢀCu(2)
C(41)ꢀAu(2)ꢀP(2)
N(2)ꢀCu(1)ꢀC(2)
N(2)ꢀCu(1)ꢀC(1)
C(2)ꢀCu(1)ꢀC(1)
N(2)ꢀCu(1)ꢀP(3)
121.6(4)
175.6(2)
104.5(3)
136.7(3)
34.0(3)
107.1(2)
of the precursor complex [Au(CtCPh)(PPh3)]. This complex
shows absorption bands in the range 268ꢀ276 nm characteristic
of triphenylphosphine, probably in the phenyl groups of the
phosphine ligands (IL ππ* transitions), since similar absorption
bands are also observed in [AuClPPh3].17 In addition, the bands
assigned to π f π*(CtC) are reported at 317ꢀ335 nm, as in
the precursor complex [Au(CtCPh)(PPh3)].18 Therefore, the
broad band that appears in the range 270ꢀ320 nm in the
complexes would involve both types of transitions.
Figure 5. Electronic absorption spectrum of 4 in dichloromethane
solution at 298 K.
220 nm (ε = 12 595 molꢀ1 L cmꢀ1) and 275 nm (ε = 24 185
molꢀ1 L cmꢀ1) with a tail extending to ca. 325 nm appears. The
position of the first maximum can be assigned to a transition
located in the pyridine ring, probably between ππ* orbitals. This
assignation is in accordance with the data obtained from gold(I)
pyridine complexes, which show absorptions at similar ener-
gies.19 As before, the maximum at lower energy could contain the
In the case of the precursor complex [Au(CtCPy)(PPh3)]
(5) a broad and poorly structured band with two maxima at
2601
dx.doi.org/10.1021/om200397t |Organometallics 2012, 31, 2597–2605

Organometallics
ARTICLE
Table 4. Photophysical Data for Complexes 2ꢀ8 in Solution
soln at room tempa
glass solnb
compd
excitation λmax/nm
emission λmax/nm (τ/μs)
excitation λmax/nm
emission λmax/nm
2
3
4
5
6
7
8
305
419 (11)
285
485
315
430, 455c (9)
408, 432, 458c (10)
450 (10)
305
465
445, 485c
295, 330, 375
308, 360
307, 370
313, 360
355, 372, 392
330
285
460
460 (10)
300
470
460 (10)
406, 432, 459c (9)
300
470
288, 355
516
a In dicloromethane at 298 K. b In CH2Cl2/MeOH/EtOH (1/2/8). c Vibronic-structured emission band.
Table 5. Photophysical Data for Complexes 2ꢀ8 in the Solid State
solid at room temp (298 K)
solid at low temp (77 K)
compd
excitation λmax/nm
emission λmax/nm (τ/μs)
excitation λmax/nm
emission λmax/nm
2
3
4
5
6
7
8
280, 360
345
490 (26)
280, 350
345
465
427, 467, 510a
426, 448, 457, 469, 481, 493, 506a
418, 437, 449, 461, 483, 496, 510a
482 (41)
321, 366
313
475a (13)
420, 447, 460a (5)
488 (20)
323
274
280, 350
275, 320
360
275, 360
275
475
470
600
480 (32)
542 (13)
340
a Broad and partially structured emission band.
transitions characteristic of triphenylphosphine and the alkynyl
ligands. In the case of the polynuclear complexes 6ꢀ8, all of them
show almost identical spectra with maxima at 230 nm and a
shoulder at 290 nm that is more evident in the case of complex 6.
Very interestingly, in all the described polynuclear complexes,
the expected red shift of the absorptions of the alkynyl ligands, as
a consequence of the lowering of the π* orbital by the π
coordination of this ligand to the metal centers, is not apparent.
This result perhaps is indicative of a weaker coordination of these
metals to the alkynyl unit in solution, or even their complete
dissociation, although it is also possible that the expected shift is
masked by the broadness of the absorptions from the triphenyl-
phosphine ligands.
The emission data of 2ꢀ8 are summarized in Tables 4 and 5.
These AuꢀAu-, AuꢀAg-, or AuꢀCu-containing complexes
show intense room- and low-temperature luminescence in both
the solid state and solution with lifetimes in the microsecond
range (see the spectra of 3 in Figure 6, as an example). These
values together with the relatively large Stokes shifts are sugges-
tive of triplet excited-state characters.
Figure 6. Normalized excitation and emission spectra of 3 in dichlor-
omethane solution at 298 K.
In the solid-state spectra of complexes 2ꢀ4 at room tempera-
ture a slight shift to lower energies in the sequence Cu > Ag > Au
is observed. Also, an incipient vibrational structure begins to
appear. This is evident in the spectra at 77 K, especially in the case
of the goldꢀcopper complex (see Figure 7). At room tempera-
ture this complex shows a broad band in the solid-state spectra
centered at approximately 475 nm. The differences in energies
between the copper derivative and the gold and silver dinuclear
complexes can be related to the participation of the heterometal
centers in the excited states responsible for the emissions. In
contrast, at low temperature, the spacing between maxima in
the solution spectrum of the goldꢀcopper derivative of ca.
1400 cmꢀ1 is in line with the CdC stretching frequencies of
the phenyl rings, indicative of the involvement of the Ph rings in
the excited-state origin. In the rest of the complexes the resolu-
tion of the spectra does not permit confirmation of this fact.
As has been reported, heterometallic complexes containing
platinum and silver or copper with phenylacetylide moieties
show emissions substantially dependent on the ease of MMLCT
(dσ*Pt2 f pσ(Pt2)π*(CtCR)) transitions. Thus, the presence
of the heterometals produces a reduction of electron density at
platinum as a result of an increase of the π-accepting ability of the
2602
dx.doi.org/10.1021/om200397t |Organometallics 2012, 31, 2597–2605

Organometallics
ARTICLE
Figure 8. Normalized solid-state emission spectra of 4 and 8 at 298 K.
Figure 7. Solid-state emission spectrum of 4 at 77 K.
similar assignment. Interestingly, the goldꢀcopper complex 8
shows a band shifted to red (542 nm) with respect to that found
in the dinuclear complex 4 (475 nm) (see Figure 8). Previous
studies of heteropolynuclear goldꢀcopper complexes carried out
by our group established that, on irradiation with UV light, the
copper center together with the electron-rich gold atom can act
as a source of electron density and the aromatic nitrogen donor
ligand as a receptor of it, forming an MMLCT (metalꢀmetal to
ligand charge transfer) excited state.23 In this case, the emission
energies in the solid state or in glassy solution at low temperature
differ considerably in energy from those of the other complexes
in the same media, suggesting that the excited states responsible
for the emissions are different. Therefore, for this low-energy
emission we propose that the excited state arises from an
admixture of IL and M(Cu)L(pyridine) CT transitions.
PhCtC groups upon π donation to Ag or Cu, resulting in a
narrowing of the HOMOꢀLUMO gap and, hence, a lower
emission energy.20 In addition, in related [R3PAuCtCC-
(CH3)dCH2] complexes, the π coordination of Cu+ or Ag+
ions produces a lowering of the π*(CtCR) orbital, giving rise to
lower energy emissions. Between them, the slightly higher emis-
sion of the silver as compared to that of the copper derivative has
been ascribed to the weaker Lewis acidity of Ag(I).21
Similarly, in the case of [Au(CtCPh)(PPh3)] the emission
3
origin is derived from an admixture of metal perturbed [π f
π*(CtC)] IL and 3[σ(AuꢀP) f π*(CtC)] MLCT states.17,22
Therefore, the coordination of the heterometals would produce
effects in the emission spectra similar to those described if the excited
states responsible for the emissions were formed in those transitions.
We propose that in complexes 2ꢀ4 the transitions that are the
3
origin of the luminescence are an admixture of IL(ππ*) states,
’ CONCLUSIONS
mostly located in the phenyl rings of the triphenylphosphine ligands,
slightly perturbed by the metals, although a contribution of the
π*(CtC) orbitals cannot be excluded.
The incorporation of coinage metal fragments into neutral
gold acetylide starting materials is favored by the high π-electron
density of the alkyne and the formation of strong metalꢀgold
interactions that stabilize the structures of discrete cationic
bimetallic complexes.
Similarly, in the case of complexes 5ꢀ8 with the ligand ꢀCt
CPy, they all display luminescence in the solid state at room or at
low temperature and in fluid solution (see Tables 4 and 5), but
with some differences with respect to those previously described.
First, the energies for the precursor gold complex [Au(CtCPy)-
(PPh3)] (5) and the polynuclear gold and silver derivatives in
solution are virtually the same, indicating similar excited states
responsible for the emissions, and therefore, we can propose that
the donation of electron density from the acetylide moieties to the
metals through their coordination does not affect the orbitals that
contribute to the excited states. In the case of the tetranuclear
goldꢀcopper complex a vibronic structure is observed in the fluid
solution at room temperature with bands at 406, 432, and 459 nm,
similar to those in the goldꢀcopper complex 4 noted previously.
This coincidence rules out the possibility that the excited states in
solution are influenced by the substituent of the acetylide (pyridyl or
phenyl) and, hence, by their donor capabilities, by the number of
metalꢀmetal interactions, or by the number of phosphines bonded
to the copper centers; in contrast, this coincidence seems to confirm
the involvement of the Ph groups in the excited-state origin.
In the solid-state spectra, the emissions of the dinuclear gold
and silver complexes are also similar to those in the previous
phenylacetylide derivatives 2 and 3, and therefore, we propose a
This coordination mode is confirmed by the crystallographic
data, which reveal that the metal of the cationic moiety is situated
at asymmetrically short distances to both carbons of the alkyne
and to the gold atom from the starting acetylide substrate. This
proximity is observed in both examples of goldꢀgold and goldꢀ
silver complexes. However, the crystal structure obtained for the
complex of copper and pyridine acetylide reveals a very different
disposition. This metal coordinates symmetrically to both carbon
atoms of the alkyne group and also to the pyridine nitrogen. The
lack of proximity of copper to the gold atom indicates that this
interaction is not necessary for the stabilization of the structure.
The compounds described in this paper show intense room-
and low-temperature luminescence. After the optical behavior is
analyzed, the origin of the luminescence in most of the states
studied is assigned to an 3IL(ππ*) located in the phenyl rings of
the phosphine ligand where the metal is weakly involved,
although a contribution from the acetylene ligand cannot be
excluded. In the case of the copper complexes, solution excited
states do not seem to be influenced by the acetylene substituent
or the structure of the compound, whereas in the solid state the
2603
dx.doi.org/10.1021/om200397t |Organometallics 2012, 31, 2597–2605

Organometallics
ARTICLE
assignment of the origin is clearly different, being proposed as an
admixture of IL and MLCT for the dinuclear compound.
Synthesis of [AuCu(CtCPh)(PPh3)3]NO3 (4). [Cu(O2NO)-
(PPh3)2] (130 mg, 0.2 mmol) was added to a THF (20 mL) solution of
[Au(CtCPh)PPh3] (1; 112 mg, 0.2 mmol). The resulting solution was
stirred under a nitrogen atmosphere for 1.5 h and concentrated under
vacuum to ca. 2 mL. The white solid was obtained after Et2O addition
(130 mg). Yield: 54%. 31P{1H} NMR (CDCl3, 20 °C): δ 0.0 (m, 3P,
PPh3). 31P{1H} NMR (HDA, ꢀ80 °C): δ 42.0 (s, AuPPh3), ꢀ2.3 (s, 2P,
Cu(PPh3)2). 1H NMR (CDCl3, 20 °C): δ 7.47ꢀ7.10 (m, 50 H, Ph). IR
(solid): ν 1071 (w, NO3), 998 (m, NO3), 691 cmꢀ1 (vs, NO3). MS
’ EXPERIMENTAL SECTION
1
Instrumentation. Solution H and 31P{1H} NMR spectra were
recorded using a Bruker ARX 400 spectrometer and a Bruker Avance II
300 spectrometer. The chemical shifts (δ, ppm) were referenced to
1
residual solvent resonances and external 85% H3PO4 in the H and
+
(ESI+): m/z (%) 587 (100) [Cu(PPh3)2 ], 885 (10) [M+ ꢀ PPh3].
31P{1H} spectra, respectively. Mass spectra were recorded both with a
ESI-TOF MicrotofQ instrument in MeOH and with a MALDI-TOF
Microflex instrument with a N2 laser (337 nm, 3.68 eV) ionization
source, with DITRANOL matrix. Infrared spectra were recorded in the
range 4000ꢀ250 cmꢀ1 on a Perkin-Elmer Spectrum 100 FTIR spectro-
meter. C, H, N, and S analyses were carried out with a Perkin-Elmer
2400 microanalyzer. UV/vis spectra were recorded with an Evolution
600 spectrophotometer (dichloromethane 5 ꢁ 10ꢀ5 M solutions).
Steady-state photoluminescence spectra were recorded with a Jobin-
Yvon Horiba Fluorolog FL-3 spectrometer using band pathways of 3 nm
for both excitation and emission. Phosphorescence lifetimes were
recorded with a Fluoromax phosphorimeter accessory containing a
UV xenon flash tube at a flash rate between 0.05 and 25 Hz. The lifetime
data were fit using the Jobin-Yvon software package24 and the Origin 5.0
program.25
Anal. Calcd for C62H50AuCuNO3P3: C, 61.52; H, 4.16; N, 1.16. Found:
C, 61.57; H, 4.41; N, 1.36.
Synthesis of [Au(CtCpy)(PPh3)] (5). A mixture of HCtCPy
(0.022 mL, 0.2 mmol) and [Au(acac)PPh3] (0.112 g, 0.2 mmol) in
dichloromethane (10 mL) was stirred for 2.5 h. Then the volume of the
solution was reduced to 2 mL and hexane was added to give 5 as a white
precipitate (84 mg). Yield: 75%.
Synthesis of [Au2(CtCPy)(PPh3)3]OTf (6). To a solution of
[Au(CtCpy)PPh3] (5; 112 mg, 0.2 mmol) in CH2Cl2 (20 mL) was
added [Au(PPh3)2]OTf (175 mg, 0.2 mmol). The mixture was stirred
for 1.5 h at room temperature and concentrated to 2 mL. The addition of
Et2O caused the precipitation of 6 as a white solid (166 mg). Yield: 58%.
31P{1H} NMR (CDCl3, ꢀ50 °C): δ 44.4 (s, 2P, Au(PPh3)2), 41.5 (s,
AuPPh3). 19F NMR (CDCl3, 20 °C): δ ꢀ78.0 (s, CF3SO3). 1H NMR
(CDCl3, 20 °C): δ 8.43 (ddd, 3J(Ha,Hb) = 4.9 Hz, 4J(Ha,Hc) = 1.7 Hz,
5J(Ha,Hd) = 0.9 Hz, Ha), 7.60ꢀ7.35 (m, 46 H, Ph + Hd), 7.32 (d00t00,
3J(Hc,Hb) = 7.7 Hz), 7.03 (ddd, 3J(Hb,Hc) = 7.7 Hz, 4J(Hb,Ha) = 4.9 Hz,
5J(Hb,Hd) = 1.2 Hz, Hb). IR (solid): ν 2110 (vw, CtC), 1263 (vs, br,
CF3SO3), 1149 cmꢀ1 (m, br, CF3SO3). MS (MALDI+/DIT): m/z (%)
Starting Materials. The starting materials [Au(acac)(PPh3)],26
[M(PPh3)2]OTf (M = Au, Ag),27,28 and [Cu(O2NO)(PPh3)2]29 were
prepared analogously to published procedures. All other reagents were
commercially available.
Solvent and Reagent Pretreatment. Solvents were purchased
from commercial sources; dichloromethane and THF were distilled
prior to use. Reactions involving copper(I) starting materials were
carried out under an atmosphere of purified argon. For reactions
involving silver(I), the flasks were covered with aluminum foil to protect
from light.
Synthesis of [Au(CtCPh)(PPh3)] (1). HCtCPh (0.022 mL, 0.2
mmol) was added to a solution of [Au(acac)PPh3] (0.112 g, 0.2 mmol)
in dichloromethane (10 mL). The mixture was stirred for 2.5 h; then the
volume was reduced to 2 mL and hexane was added to precipitate the
product as a white powder (86 mg). Yield: 77%.
721 (100) [Au(PPh3)2 ], 1020 (14) [M+ ꢀ PPh3], 1282 (2) [M+]. Anal.
+
Calcd for C62H49Au2F3NO3P3S: C, 52.00; H, 3.45; N, 0.98; S, 2.24.
Found: C, 51.98; H, 3.52; N, 0.94; S, 2.33.
Synthesis of [AuAg(CtCPy)(PPh3)3]OTf (7). [Ag(PPh3)2]-
OTf (156 mg, 0.2 mmol) was added to an acetone (20 mL) solution
of [Au(CtCPy)PPh3] (112 mg, 0.2 mmol). After 1 h of stirring, the
reaction mixture was concentrated under vacuum and Et2O was added
to give a white precipitate (210 mg). Yield: 78%. 31P{1H} NMR (CDCl3,
20 °C): δ 41.0 (m, AuPPh3), 12.3 (m, 2P, Ag(PPh3)2). 31P{1H} NMR
(HDA, ꢀ80 °C): δ 40.0 (s, AuPPh3), 8.8 (2d, J(107Ag,P) = 411 Hz,
J(109Ag,P) = 475 Hz, 2P; Ag(PPh3)2). 19F NMR (CDCl3, 20 °C): δ ꢀ77.9
(s, 3F, CF3SO3). 1H NMR (CDCl3, 20 °C): δ 8.19 (d, 3J(Ha,Hb) = 4.4 Hz,
Ha), 7.57 (m, Hb), 7.41ꢀ7.10 (m, 47 H, Ph + Hc + Hd). IR (solid): ν 1258
(vs, br, CF3SO3), 1148 cmꢀ1 (m, br, CF3SO3);. MS (MALDI+/DIT): m/z
Synthesis of [Au2(CtCPh)(PPh3)3]OTf (2). To a solution of
[Au(CtCPh)PPh3] (1; 112 mg, 0.2 mmol) in CH2Cl2 (20 mL) was
added [Au(PPh3)2]OTf (175 mg, 0.2 mmol). The mixture was stirred
for 1.5 h and concentrated under vacuum to ca. 2 mL. The addition of
Et2O caused the precipitation of the compound 2 as a white solid (214
mg). Yield: 75%. 31P{1H} NMR (CDCl3, ꢀ50 °C): δ 43.4 (s, 2P,
Au(PPh3)2), 41.0 (s, AuPPh3). 19F NMR (CDCl3, 20 °C): δ ꢀ78.0 (s,
CF3SO3). 1H NMR (CDCl3, 20 °C): δ 7.70ꢀ7.20 (m, 50 H, Ph). IR
(solid): ν 1264 (vs, br), 1147 cmꢀ1 (m, br, CF3SO3). MS (MALDI+/
+
(%) 721 (100) [Au(PPh3)2 ], 822 (55) [M+ ꢀ AgPPh3]. Anal. Calcd for
C62H49AgAuF3NO3P3S: C, 55.45; H, 3.68; N, 1.04; S, 2.39. Found: C,
55.40; H, 3.74; N, 1.01; S, 2.56.
Synthesis of [Au2Cu2(CtCPy)2(PPh3)4](NO3)2 (8). Solid
[Cu(O2NO)(PPh3)2] (130 mg, 0.2 mmol) was added to a CH2Cl2
(20 mL) solution of [Au(CtCPy)PPh3] (112 mg, 0.2 mmol). The
solution, which turned yellow immediately, was stirred under nitrogen
for 3 h and concentrated under vacuum to ca. 2 mL. A yellow solid was
obtained after hexane addition (136 mg). Yield: 71%. 31P{1H} NMR
(CDCl3, ꢀ50 °C): δ 40.9 (m, Au(PPh3)), ꢀ0.4 (m, CuPPh3). 1H NMR
(CDCl3): δ 8.45 (m, 2Ha), 7.51 (m, 2Hc), 7.40ꢀ7.15 (m, 62 H, 12 Ph
+2Hd), 7.05 (m, 2Hb). IR (solid): ν 2112 (w, CtC), 1071 (w, NO3),
997 (m, NO3), 690 cmꢀ1 (s, NO3). MS (MALDI+/DIT): m/z (%) 587
+
DIT): m/z (%) 721 (100) [Au(PPh3)2 ], 1019 (17) [M+ ꢀ PPh3]. Anal.
Calcd for C63H50Au2F3O3P3S: C, 52.88; H, 3.52; S, 2.24. Found: C,
52.95; H, 3.54; S, 2.74.
Synthesis of [AuAg(CtCPh)(PPh3)3]OTf (3). To an acetone
solution (20 mL) of [Au(CtCPh)PPh3] (1; 112 mg, 0.2 mmol) was
added [Ag(PPh3)2]OTf (156 mg, 0.2 mmol). After 1 h of stirring, the
reaction mixture was concentrated under vacuum and Et2O was added
to give a white precipitate (174 mg). Yield: 65%. 31P{1H} NMR (CDCl3,
20 °C): δ 40.8 (m, AuPPh3), 10.9 (m, 2P, Ag(PPh3)2). 31P{1H} NMR
(CDCl3, ꢀ50 °C): δ 39.9 (s, AuPPh3), 8.8 (2d, J(107Ag,P) = 424 Hz,
J(109Ag,P) = 482 Hz, 2P; Ag(PPh3)2). 19F NMR (CDCl3): δ ꢀ77.9 (s, 3F,
CF3SO3). 1H NMR (CDCl3): δ 7.57ꢀ7.09 (m, 50 H, Ph). IR (solid): ν
1264 (vs, br, CF3SO3), 1146 cmꢀ1 (m, br, CF3SO3). MS (MALDI+/DIT):
(87) [Cu(PPh3)2 ], 721 (100) [Au(PPh3)2 ], 886 (25) [(M/2)+], 1185
+
+
+
(5) [Au2Cu(CtCpy)2(PPh3)2 ]. Anal. Calcd for C86H68Au2Cu2-
N4O6P4: C, 54.41; H, 3.61; N, 2.95. Found: C, 54.78; H, 3.52; N, 2.94.
Crystallography. Data were registered on an Oxford Diffraction
Xcalibur (2, 7, and 8) or a Bruker AXS BV Kappa CCD diffractometer
(3). The crystals were mounted in inert oil on a glass fiber and
transferred to the cold gas stream of the corresponding diffracto-
meter. Data were collected using monochromated Mo KR radiation
+
m/z (%) 631 (8) [Ag(PPh3)2 ], 669 (7) [M+ ꢀ 2PPh3], 931 (8) [M+ ꢀ
PPh3]. Anal. Calcd for C63H50AgAuF3O3P3S: C, 56.39; H, 3.76; S, 2.39.
Found: C, 56.46; H, 3.88; S, 2.41.
2604
dx.doi.org/10.1021/om200397t |Organometallics 2012, 31, 2597–2605

Organometallics
ARTICLE
(λ = 0.710 73) in the ω-scan mode. Absorption corrections based on
multiple scans were applied. The structures were solved by direct
methods and refined on F2 using the program SHELXL-97.30 All non-
hydrogen atoms were refined anisotropically. Hydrogen atoms were
included using a riding model. Further crystal data are given in Table 1.
J. Organomet. Chem. 1986, 302, C10. (d) Ferrer, M.; Rosell, O.; Seco, M.;
Pellinghelli, M. A.; Tiripicchio, A. Organometallics 1995, 14, 57. (e)
K€ohler, K.; Silverio, S. J.; Hyla-Kryspin, I.; Gleiter, R.; Zsolnai, L.; Driess,
A.; Huttner, G.; Lang, H. Organometallics 1997, 16, 4970. (f) Chen, Z. N.;
Zhao, N.; Fan, Y.; Ni, J. Coord. Chem. Rev. 2009, 253, 1.
(7) (a) de la Riva, H.; Nieuwhuyzen, M.; Mendicute-Fierro, C.;
Raithby, P. R.; Male, L.; Lagunas, M. C. Inorg. Chem. 2006, 45, 1418. (b)
Wei, Q.-H.; Zhang, L.-Y.; Yin, G.-Q.; Shi, L.-X.; Chen, Z.-N. J. Am. Chem.
Soc. 2004, 126, 9940. (c) Abu-Salah, O. M.; Al-Ohaly, A. R. J. Organomet.
Chem. 1983, 255, C39. (d) Yip, S.-K.; Cheng, E. C.-C.; Yuan, L.-H.; Zhu,
N.; Yam, V.W.-W. Angew. Chem., Int. Ed. 2004, 43, 4954. (e) Koshevoy,
I. O.; Lin, C.-L.; Karttunen, A. J.; J€anis, J.; Haukka, M.; Tunik, S. P.;
Chou, P. T.; Pakkanen, T. A. Inorg. Chem. 2011, 50, 2395.
(8) (a) Vergara, E.; Cerrada, E.; Casini, A.; Zava, O.; Laguna, M.;
Dyson, P. J. Organometallics 2010, 29, 2596. (b) Kilpin, K. J.; Horvath,
R.; Jameson, G. B.; Telfer, S. G.; Gordon, K. C.; Crowley, J. D.
Organometallics 2010, 29, 6186.
’ ASSOCIATED CONTENT
S
Supporting Information. CIF files giving crystallo-
b
graphic data for 2, 3, 7, and 8. This material is available free of
charge via the Internet at http://pubs.acs.org. The files CCDC
792104, 792105, 792107, and 792108 also contain supplemen-
tary crystallographic data for this paper. These data can be
obtained free of charge from the Cambridge Crystallographic
Data Centre via www.ccdc.cam.ac.uk/data_request/cif.
(9) (a) Hashmi, A. S. K.; Rudolph, M. Chem. Soc. Rev. 2008,
37, 1766. (b) Teles, J. H.; Brode, S.; Teles, M. C. Angew. Chem., Int.
Ed. 1998, 37, 1415.
(10) (a) Vicente, J.; Chicote, M. T. Coord. Chem. Rev. 1999,
193ꢀ195, 1143. (b) Vicente, J.; Chicote, M. T.; Abrisqueta, M. D.;
Gonzꢀalez-Herrero, P.; Guerrero, R. Gold Bull. 1998, 31/3, 83.
(11) Bruce, M. I.; Horn, E.; Matisons, J. G.; Snow, M. R. Aust. J.
Chem. 1984, 37, 1163.
’ AUTHOR INFORMATION
Corresponding Author
*Fax: (+34)976 761187. E-mail: alaguna@unizar.es.
’ ACKNOWLEDGMENT
We thank the Ministerio de Ciencia e Innovaciꢀon (CTQ2010-
20500) and the Departamento de Ciencia, Tecnología y Uni-
versidad del Gobierno de Aragon - Fondo Social Europeo (E77)
for financial support.
(12) Mukherjee, R. In Comprehensive Coordination Chemistry II;
McCleverty, J. A., Meyer, T. J., Eds.; Elsevier: Oxford, U.K., 2004; Vol. 6, p 747.
(13) Bruce, M. I.; Duffy, D. N. Aust. J. Chem. 1986, 39, 1697.
(14) Naulty, R. H.; Cifuentes, M. P.; Humphrey, M. G.; Houbrechts,
S.; Boutton, C.; Persoons, A.; Heath, G. A.; Hickless, D. C. R.; Luther-
Davies, B.; Samoc, M. J. Chem. Soc., Dalton Trans. 1997, 4167.
’ DEDICATION
ꢀ
(15) Vicente, J.; Chicote, M. T.; Alvarez-Falcꢀon, M. M.; Jones, P. J.
Organometallics 2005, 24, 4666.
(16) Yam, V. W. W.; Fung, W. K. M.; Cheung, K. K. Angew. Chem.,
Int. Ed. Engl. 1996, 35, 1100.
(17) (a) Li, D.; Hong, X.; Che, C. M.; Lo, W. C.; Peng, S. M. J. Chem.
Soc., Dalton Trans. 1993, 2929. (b) Yam, V. W. W.; Choi, S. W. K.
J. Chem. Soc., Dalton Trans. 1996, 4227. (c) Yam, V. W. W.; Choi,
S. W. K.; Cheung, K. K. Organometallics 1996, 15, 1734. (d) Yam,
V. W. W.; Cheung, K. L.; Yuang, L. H.; Wong, K. M. C.; Cheung, K. K.
Chem. Commun. 2000, 16, 1513.
Dedicated to the memory of Prof. F. Gordon A. Stone.
’ REFERENCES
(1) (a) Schmidbaur, H. Gold Bull. 2000, 33/1, 3. (b) Schmidbaur,
H.; Schier, A. Chem. Soc. Rev. 2008, 37, 1931. (b) Horvath, U. E. I.;
McKenzie, J. M.; Cronje, S.; Raubenheimer, H. G.; Barbour, L. J. Chem.
Commun. 2009, 6598.
(2) Schmidbaur, H.; Grohman, A.; Olmos, M. E. Gold: Progress in
Chemistry, Biochemistry and Technology; Schmidbaur, H., Ed.; Wiley:
Chichester, U.K., 1999; p 647.
(18) Lu, X. X.; Li, C. K.; Cheng, E. C. C.; Zhu, N.; Yam, V. W. W.
Inorg. Chem. 2004, 43, 2225.
ꢀ
(19) Fernꢀandez, E. J.; Laguna, A.; Lꢀopez-de-Luzuriaga, J. M.; Monge,
M.; Montiel, M.; Olmos, M. E.; Pꢀerez, J.; Rodríguez-Castillo, M. Gold
Bull. 2007, 40/3, 172.
(20) Yam, V. W. W.; Hui, C. K.; Wong, K. M. C.; Zhu, N.; Cheung,
K. K. Organometallics 2002, 21, 4326.
(21) Yam, V. W. W.; Cheung, K. L.; Cheng, E. C. C.; Zhu, N.;
Cheung, K. K. Dalton Trans. 2003, 1830.
(22) Irwin, M. J.; Vittal, J. J.; Puddephatt, R. J. Organometallics 1997,
16, 3541.
(23) Fernꢀandez, E. J.; Laguna, A.; Lꢀopez de Luzuriaga, J. M.; Monge,
M.; Montiel, M.; Olmos, M. E. Inorg. Chem. 2005, 44, 1163.
(24) DATAMAX 2.20; Jobin Yvon, Inc., Edison, NJ, 2001.
(25) Origin 5.0; Microcal Software, Inc., Northampton, MA, 1991.
(26) Gibson, D.; Johnson, B. F. G.; Lewis, J. J. Chem. Soc. A 1970, 367.
(27) Usꢀon, R.; Laguna, A.; Laguna, M.; Jimꢀenez, J.; Gꢀomez, M. P.;
Sainz, A.; Jones, P. G. J. Chem. Soc., Dalton Trans. 1990, 3457.
(28) Bardají, M.; Crespo, O.; Laguna, A.; Fischer, A. K. Inorg. Chim.
Acta 2000, 34, 7.
(3) (a) Hogarth, G.; Alvarez-Falcꢀon, M. M. Inorg. Chim. Acta 2005,
358, 1386. (b) Cheung, K.-L.; Yip, S.-K.; Yam, V. W.-W. J. Organomet.
Chem. 2004, 689, 4451. (c) Burchell, T. J.; Jennings, M. C.; Puddephatt,
R. J. Inorg. Chim. Acta 2006, 359, 2812. (d) Packheiser, R.; Jakob, A.;
Ecorchard, P.; Walfort, B.; Lang, H. Organometallics 2008, 27, 1214. (e)
Katz, M. J.; Sakai, K.; Leznoff, D. B. Chem. Soc. Rev. 2008, 37, 1884. (f)
Himmelspach, A.; Finze, M.; Raub, S. Angew. Chem., Int. Ed. 2011, 50, 2628.
(4) (a) Vicente, J.; Gil-Rubio, J.; Barquero, N.; Jones, P. G.; Bautista, D.
Organometallics 2008, 27, 646. (b) Koshevoy, I. O.; Haukka, M.; Selivanov,
S. I.; Tunik, S. P.; Pakkanen, T. A. Chem. Commun. 2010, 46, 8926.
(5) (a) Lu, W.; Zhu, N.; Che, C.-M. J. Am. Chem. Soc. 2003,
125, 16081. (b) Wong, K. M.-C.; Hung, L.-L.; Lam, W. H.; Zhu, N.;
Yam, V.W.-W. J. Am. Chem. Soc. 2007, 129, 11662. (c) Wei, Q. H.; Yin,
G. Q.; Zhang, L. Y.; Chen, Z. N. Organometallics 2006, 25, 4941. (d)
Wei, Q. H.; Zhang, L. Y.; Yin, G. Q.; Shi, L. X.; Chen, Z. N.
Organometallics 2005, 24, 3818. (e) Koshevoy, I. O.; Ostrova, P. V.;
Karttunen, A. J.; Melnikov, A. S.; Khodorkovskiy, M. A.; Haukka, M.;
J€anis, J.; Tunik, S. P.; Pakkanen, T. A. Dalton Trans. 2010, 39, 9022.
(f) Lin, Y.; Yin, J.; Yuan, J.; Hu, M.; Li, Z.; Yu, G. A.; Liu, S. H.
Organometallics 2010, 29, 2808. (g) Nguyen, M. H.; Yip, J. H. K.
Organometallics 2010, 29, 2422. (h) Nguyen, M. H.; Yip, J. H. K.
J. Am. Chem. Soc. 2010, 132, 12307.
(29) Kubas, G. J. Inorg. Synth. 1979, 19, 90.
(30) Sheldrick, G. M. SHELXL-97, a Program for Crystal Structure
Refinement; University of G€ottingen, G€ottingen, Germany, 1997.
(6) (a) Chui, S. S. Y.; Ng, M. F. Y.; Che, C.-M. Chem. Eur. J. 2005,
11, 1739. (b)Cabrera, A.; Delgado, E.; Pastor, C.; Maestro, M. A.; Zamora,
F. Inorg. Chim. Acta 2005, 358, 1521. (c) Abu-Salah, O. M.; Knobler, C. B.
2605
dx.doi.org/10.1021/om200397t |Organometallics 2012, 31, 2597–2605