Study of the effect of the phosphane bridging chain nature on the structural and photophysical properties of a series of gold(I) ethynylpyridine complexes

Article abstract of DOI:10.1002/ejic.200800167

Alkynyl Au^I complexes of the type [Au(C≡CC ₅H₄N)(PPh₃)] (1) [Au₂(C≡ CC₅H₄N)₂ (diphosphane)] [diphosphane = bis(diphenylphosphanyl)methane (2), bis(diphenylphosphanyl)isopropane] (3), bis(diphenylphosphanyl)acetylene (4), 1,2-bis(diphenylphosphanyl)ethane (5), 1,3-bis(diphenylphosphanyl)propane (6), 1,4-bis(diphenylphosphanyl)butane (7), 1,1′-bis(diphenylphosphanyl)ferrocene (8) and [Au₃(C≡ CC₅H₄N)₃(triphos)] [triphos = 1,1,1-tris(diphenylphosphanylmethyl)ethane] (9) were prepared by reaction of [Au(C≡CC₅H₄N)]_n with the suitable phosphane. Determination of the X-ray crystal structures of several compounds bearing different carbon backbones between the phosphorus atoms reveals the influence of the nature of the phosphane spacer on the establishment of intra and/or intermolecular gold-gold interactions. The absorption and emission properties of the complexes were analysed by taking into account the presence or absence of intermetallic interactions. Although UV/Vis spectra show differences for compounds with intramolecular Au-Au contacts, a conclusive trend was not observed in the emission behaviour. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.

Full text of DOI:10.1002/ejic.200800167

FULL PAPER
DOI: 10.1002/ejic.200800167
Study of the Effect of the Phosphane Bridging Chain Nature on the Structural
and Photophysical Properties of a Series of Gold(I) Ethynylpyridine Complexes
Montserrat Ferrer,*[a] Albert Gutiérrez,[a] Laura Rodríguez,[a,b] Oriol Rossell,[a]
João C. Lima,[b] Mercè Font-Bardia,[c] and Xavier Solans[c]
Keywords: Gold / Aurophilicity / Phosphanes / Alkynes / Luminescence / UV/Vis spectroscopy
Alkynyl AuI complexes of the type [Au(CϵCC5H4N)(PPh3)]
(1) [Au2(CϵCC5H4N)2 (diphosphane)] [diphosphane = bis(di-
phenylphosphanyl)methane (2), bis(diphenylphosphanyl)iso-
propane] (3), bis(diphenylphosphanyl)acetylene (4), 1,2-
bis(diphenylphosphanyl)ethane (5), 1,3-bis(diphenylphos-
phanyl)propane (6), 1,4-bis(diphenylphosphanyl)butane (7),
1,1Ј-bis(diphenylphosphanyl)ferrocene (8) and [Au3(CϵC-
C5H4N)3(triphos)] [triphos = 1,1,1-tris(diphenylphosphanyl-
methyl)ethane] (9) were prepared by reaction of
[Au(CϵCC5H4N)]n with the suitable phosphane. Determi-
nation of the X-ray crystal structures of several compounds
bearing different carbon backbones between the phosphorus
atoms reveals the influence of the nature of the phosphane
spacer on the establishment of intra and/or intermolecular
gold–gold interactions. The absorption and emission proper-
ties of the complexes were analysed by taking into account
the presence or absence of intermetallic interactions. Al-
though UV/Vis spectra show differences for compounds with
intramolecular Au–Au contacts, a conclusive trend was not
observed in the emission behaviour.
(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim,
Germany, 2008)
(phosphane = PPh3,[25] PCy3[26]), there is no previous re-
ports on the parent polyphosphane complexes, which is
rather surprising in view of the tempting possibilities these
gold(I) derivatives offer. Even more, the incorporation of
gold(I) alkyne fragments into supramolecular architectures
containing cavities can confer upon them emissive proper-
ties that could allow their utilisation as sensors in molecular
recognition processes.
In this work, several polyphosphane ligands were used
to prepare di- and trialkynyl gold(I) derivatives as an exten-
sion of our studies on the synthesis of suitable gold(I) alk-
ynyls[27] to be used as polytopic metalloligands in self-as-
sembly reactions. The alkynyl ligand was kept constant
while the length and/or nature of the bridging carbon chain
of the phosphane were varied to assess their effect on the
existence of intra- or intermolecular Au···Au interactions.
Moreover, a systematic analysis of their electronic absorp-
tion and emission properties was undertaken in order to
show how the observed profiles would relate to the exis-
tence of aurophilic interactions.
Introduction
During the past years, there has been a continued interest
in the chemistry of alkynyl gold(I) complexes, primary re-
sulting from their interesting physical properties such as
nonlinear optical behaviour,[1–3] liquid-crystalline proper-
ties[4,5] and photoemissive properties of the molecules and
their aggregates.[6–12] Moreover, the low steric congestion
about the linear gold(I) centre and the ability of gold(I)
to form attractive Au···Au interactions have made alkynyl
gold(I) compounds attractive candidates for the synthesis
of a wide variety of supramolecular structures[13] as poly-
mers,[14–17] macrocycles[18–20] or catenanes.[21–24]
One rather unexplored way of building up metallamacro-
cycles containing these subunits is to utilise alkynyl ligands
with a second binding site. In this context, the introduction
of ethynylpyridine fragments into alkynyl gold(I) complexes
allows the obtention of potentially useful building blocks
towards the synthesis of heterometallic macrocycles or
polymers.
Although
monophosphane
compounds
[Au(CϵCC5H4N)(phosphane)] have been recently reported
[a] Departament de Química Inorgànica, Universitat de Barcelona,
c/ Martí i Franquès 1-11, 08028 Barcelona, Spain
Fax: +34-93-490-7725
Results and Discussion
Following a literature procedure,[28] the reaction of a
dichloromethane suspension of [Au(CϵCC5H4N)]n with
either PPh3 (1 equiv.), dppm [bis(diphenylphosphanyl)-
methane], dppip [bis(diphenylphosphanyl)isopropane],
dppa [bis(diphenylphosphanyl)acetylene], dppe [1,2-bis(di-
phenylphosphanyl)ethane], dppp [1,3-bis(diphenylphos-
phanyl)propane], dppb [1,4-bis(diphenylphosphanyl)bu-
E-mail: montse.ferrer@qi.ub.es
[b] REQUIMTE, Departamento de Química. Centro de Química
Fina e Biotecnologia, Universidade Nova de Lisboa,
Quinta da Torre, 2825 Monte de Caparica, Portugal
[c] Departament de Cristal·lografia, Mineralogia i Dipòsits Min-
erals, Universitat de Barcelona,
c/ Martí i Franquès s/n, 08028 Barcelona, Spain
Supporting information for this article is available on the
WWW under http://www.eurjic.org or from the author.
Eur. J. Inorg. Chem. 2008, 2899–2909
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
2899

M. Ferrer et al.
FULL PAPER
tane] and dppf [1,1Ј-bis(diphenylphosphanyl)ferrocene] dppb, dppf and triphos compounds) or as AXXЈ (A = 13C;
(0.5 equiv.) or triphos [1,1,1-tris(diphenylphosphanylme- X = XЈ = 31P) spin systems (dppm and dppip compounds)
thyl)ethane] (0.3 equiv.) afforded the desired complexes (Figure 1). These chemical shifts and coupling constants are
[Au(CϵCC5H4N)(PPh3)] (1), [Au2(CϵCC5H4N)2(µ2-di- consistent with other reported molecules containing P–Au–
phosphane)] (2–8) or [Au3(CϵCC5H4N)3(µ3-triphos)] (9) in CϵC units.[17,26,29] In addition, the phenyl rings of dppm
a
yields greater than 60% (Scheme 1). Subsequent and dppip show multiplets or apparent triplets for their or-
recrystallisation from dichloromethane/petroleum ether or tho-, meta- and ipso-C atoms. The occurrence of second-
dichloromethane/diethyl ether mixtures gave colourless-to- order effects in this kind of compounds was attributed to a
yellow crystals of 1–9. All the synthesised compounds gave large 31P-31P coupling constant and/or to the existence of
satisfactory elemental analysis and were characterised by intramolecular gold–gold interactions in solution.[30]
1H, 31P and 13C NMR spectroscopy, mass spectrometry
(ESI+) and IR spectroscopy. The structures of complexes
3–7 and 9 were determined by X-ray crystallography.
Figure 1. Expansions of 13C NMR signals corresponding to the P–
Au–CϵC (left) and P–Au–CϵC (right) fragments for dppip com-
pound 3.Top: experimental, bottom: simulations of the A part of
AXXЈ spin system.
In sharp contrast with the other phosphanes, when the
gold polymer [Au(CϵCC5H4N)]n was treated with dppbz
[1,2-bis(diphenylphosphanyl)benzene] in
a molar ratio
Ն1:1, under the same conditions as those reported above,
the ionic compound [Au(dppbz)2][Au(CϵCC5H4N)2] (10)
was obtained (Scheme 2). Although the cationic part con-
tains a bis(chelated) tetrahedral gold atom, the anion is a
linear bis(alkynyl)gold compound recently described by
us.[27] 1H NMR and 13C NMR spectra together with MS
(ESI) spectra, which display the peaks corresponding to the
Scheme 1.
The IR spectra of all the complexes show weak absorp-
tion bands at 2103–2120 cm–1, which is typical for the
ν(CϵC) stretch of the alkynyl unit. The MS (ESI+) spectra
show the peak due to the mono- [M + H]+ (1), di- [M +
2H]2+ (2–8) or triprotonated [M + 3H]3+ (9) species as the
most intense signals.
[Au(dppbz)2]+ cation (m/z
=
1089.2) and the
[Au(CϵCC5H4N)2]– anion (m/z = 401.3), constitute clear
evidence of the nature of compound 10. This anomalous
behaviour was already observed for the analogous dppm
ligand, which gave the trinuclear complex [Au3(dppm)2-
(CϵCC6H5)2][Au(CϵCC6H5)2][31] instead of the expected
The NMR spectra of the complexes are consistent with
the proposed structures. The 1H NMR spectra show the
expected signals for the α and β protons of the pyridine
rings as well as those attributable to the phosphane ligands.
The 31P NMR spectra display a single resonance, which is
shifted downfield (ca. 50 ppm) from that of the correspond-
ing free phosphanes. The 13C NMR spectra reveal the pres-
ence of the acetylenic carbon atoms bonded to gold, as two
sets of resonances, whose assignments are based on
gHMBC and gHSQC experiments, can be found at ca. 140
(Au–CϵC) and 100 (Au–CϵC) ppm. In most of the com-
pounds, these signals exhibit coupling to the neighbouring
31P atoms (J ≈ 140 Hz and J ≈ 20 Hz for Au–CϵC and
Au–CϵC, respectively), appearing either as doublets (dppp, Scheme 2.
2900
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 2899–2909

Effects of the Phosphane Bridging Chain on AuI Complexes
dinuclear compound [Au2(CϵCC6H5)2(µ2-dppm)] when it Table 1. Selected bond lengths [Å] and angles [°] of 3.
was allowed to react with the gold polymer
[Au(CϵCC6H5)]n.
Au21···Au22
Au21–P21
Au21–C21
Au22–P22
Au22–C235
C21–C22
3.235(2)
2.284(3)
2.007(10)
2.280(3)
2.039(8)
1.195(12)
1.147(12)
P21–Au21–C21
Au21–C21–C22
P22–Au22–C235
Au22–C235–C236 169.3(9)
C21–Au21···Au22
P21–Au21···Au22
C235–Au22···Au21 107.3(2)
P22–Au22···Au21
P21–C220–P22
174.1(3)
175.2(9)
169.2(3)
92.2(3)
91.63(8)
X-ray Crystal Structures
C235–C236
In order to explore whether the nature of the carbon
chain of the phosphane can influence the existence of intra
and/or intermolecular aurophilic interactions in the solid
state, a systematic study of the crystal structures of a series
of compounds bearing phosphanes with different back-
bones was undertaken. Selected bond lengths and angles
are listed in Tables 1–6.
83.45(7)
109.2(4)
pounds: [Au2Cl2(µ2-dppe)] [3.187(1) Å],[38] [Au2Cl2(µ2-
dpma)] [dpma = bis(diphenylphosphanyl)methylphenylar-
sine]
[3.141(1) Å],[39]
[Au2(CϵCC6H5)2(µ2-dppe)]
[Au2(CN)2(µ2-dppe)]
(3.176 Å),[41]
[3.153(2) Å],[40]
The unit cell of dppip derivative 3 (one sp3 carbon atom
between the phosphorus atoms of the diphosphane) shows
two independent but closely similar molecules that display
intramolecular Au···Au contacts of 3.237(2) and 3.235(2) Å
(only one molecule is shown in Figure 2). These distances
(Table 1) are longer than that reported for the related
[Au2(µ2-dppip)2]2+ [2.9275(10) Å],[32] [Au2(CϵCC6H5)2{µ2-
Ph2PN(nPr)PPh2}] [2.8404(8) Å],[9] [Au2(CϵCC6H4Me)2-
{µ2-Ph2PN(nPr)PPh2}] [3.0708(7) Å],[9] [Au2(C14H9)2(µ2-
dppm)] [3.0121(7) Å],[33] [Au2{S2P(p-C6H4OCH3)(OC5H9)}2-
[Au2Cl2(µ2-ptp)] (ptp = 2,5-diphenylphosphanylthiophene)
[3.0966(5) Å],[42] [Au2(4-SC5H4N)2(µ2-Ph2PCH=CHPPh2)]
(3.239 Å)[43] and [Au4(CNC)(µ2-dppa)] (CNC = pyridyl-2,2-
diphenyl) [3.189(2) Å].[44] In this case, the observed torsion
angle for Au–P–PЈ–Au is 72.48°, which allows the forma-
tion of a 12-membered metallamacrocycle with each of the
Au–Au bonds lying below and above the plane defined by
the phosphorus atoms of the diphosphane. In addition, the
extended structure of 4 presents secondary C–H···π(ring)
interactions between different dimeric units that arise from
the C–H bonds of pyridine groups and the nearest aromatic
rings of either a diphosphane or a pyridine ligand.
(µ2-dppm)]
[3.0353(3) Å],[34]
[Au2(C6H5)2(µ2-dppm)]
[3.154(1) Å][35] and [Au2(C6F5)2(µ2-dppm)] [3.163(1) Å][36]
complexes, but shorter than that found for [Au2(CϵCC6H5)2-
(µ2-dppm)] [3.331(1) Å][37] or [Au2(CH3)2(µ2-dppm)]
[3.251(1) Å].[35] The observed torsion angles for Au–P–PЈ–
Au (7.81 and 6.55°) are indicative of a parallel arrangement
of the Au(CϵCC5H4N) units, which are the dihedral angles
between the two terminal pyridine rings 63.5(7) and
50.4(6)°. As it can be seen in Figure 2, one of the arms of
the molecule displays a significant deviation from linearity,
P–Au–C [170.6(3) and 169.2(3)] and Au–C–C [163.5(9) and
169.3(9)], probably as a result of packing forces.
Figure 3. Molecular structure of [Au2(CϵCC5H4N)2(µ2-dppa)](4).
Table 2. Selected bond lengths [Å] and angles [°] of 4.
Au1···Au2
Au1–P1
Au1–C1
Au2–P2
Au2–C34
C1–C2
2.9789(15)
2.271(3)
1.990(9)
2.281(2)
2.083(8)
1.251(12)
1.108(12)
1.149(12)
P1–Au1–C1
Au1–C1–C2
173.7(3)
170.5(9)
175.9(2)
171.4(8)
79.6(3)
106.46(7)
85.7(2)
P2–Au2–C34
Au2–C34–C35
C1–Au1···Au2
P1–Au1···Au2
C34–Au2···Au1
P2–Au2···Au1
C20–C21–P2
C34–C35
C20–C21
96.45(7)
175.8(9)
Figure 2. Molecular structure of [Au2(CϵCC5H4N)2(µ2-dppip)] (3).
The dppa compound (4) (two sp carbon atoms between
the phosphorus atoms) is shown in Figure 3 and its data is
The structures of the dppe (5), dppp (6) and dppb (7)
gathered in Table 2. This complex crystallises as a dimer derivatives (two, three and four methylene groups between
with inversion symmetry, which has two gold–gold interac- the phosphorus atoms, respectively) (Figure 4, Table 3; Fig-
tions [2.9789(15) Å]. The value for the Au···Au contact is ure 5, Table 4; Figure 6, Table 5 and Figure 7, Table 6) are
the shortest reported for this kind of diphosphanyl com- centrosymmetric. Both 5 and 7 display linear P–Au–CϵC–
Eur. J. Inorg. Chem. 2008, 2899–2909
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
2901

M. Ferrer et al.
FULL PAPER
units lying on the molecular plane with opposite orientation Table 4. Selected bond lengths [Å] and angles [°] of 6.
and a Au1–P1–P1a–Au1a torsion angle of 180° (diphos-
Au–P
Au–C1
C1–C2
2.2790(16)
1.985(6)
1.212(8)
P–Au–C1
175.57(17)
174.3(6)
115.50(18)
116.8(3)
phane ligand in the anti conformation). Many examples of
crystal structures for related dppe or dppb digold com-
pounds can be found in the literature. Although in the ma-
jority of them an anti conformation for both ligands is ob-
served, the association between the different molecules by
the establishment of intermolecular aurophilic interactions
can led to the formation of either polymeric chains[43,45–48]
or independently packed molecules.[34,43,49,50] In our case,
the establishment of gold–gold contacts [3.215(2) Å] be-
tween adjacent molecules for compound 5 led to the forma-
tion of a one-dimensional extended chain (Figure 5). There
are no additional interactions between the different poly-
meric chains. In contrast, the crystal structure of dppb de-
rivative 7 (Figure 6) shows the packing of simple molecular
entities with no gold–gold interactions. In this latter case,
crystallisation solvents could play an important role for the
lack of aurophilic contacts.[51]
Au–C1–C2
Au–P–C20
P–C20–C21
Figure 6. Molecular structure of [Au2(CϵCC5H4N)2(µ2-dppb)](7).
Table 5. Selected bond lengths [Å] and angles [°] of 7.
Au1–P
Au1–C15
C15–C16
2.2761(16)
2.122(6)
1.110(10)
P–Au1–C15
Au1–C15–C16
Au1–P–C13
P–C13–C14
177.63(15)
169.5(6)
113.17(17)
111.0(4)
Figure 4. Molecular structure of [Au2(CϵCC5H4N)2(µ2-dppe)](5).
Table 3. Selected bond lengths [Å] and angles [°] of 5.
Au1–P1
Au1–C1
C1–C2
2.272(3)
2.064(11)
1.009(14)
P1–Au1–C1
Au1–C1–C2
Au1–P1–C27
175.2(3)
167.5(12)
114.7(3)
Figure 7. Molecular structure of [Au2(CϵCC5H4N)2(µ2-dppp)](6).
A different situation is found in dppp compound 6 (Fig-
ure 7), in which the diphosphane adopts a less-twisted con- in [Au2(purin-6-ylamine-9-ate)2(µ2-dppp)][48] to 149.08° in
formation [torsion angle Au1–P1–P1a–Au1a equal to [Au2(SC6H5)2(µ2-dppp)];[43] this fact is in contrast with the
84.44°]. This is a common trend for dppp compounds, as a tendency of both dppe and dppb compounds to adopt tor-
CDS search for related compounds (10 structures) shows sional angles of 180°. The packing diagram shows no close
the value of the torsion angles to be in the range from 51° aurophilic intermolecular interactions.
Figure 5. Supramolecular association in 5 through intermolecular aurophilic contacts to form an infinite chain.
2902
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 2899–2909

Effects of the Phosphane Bridging Chain on AuI Complexes
Table 6. Selected bond lengths [Å] and angles [°] of 9.
The use of phosphanes with different backbones has al-
lowed us to obtain a wide range of structures (molecules
with no interactions, molecules with intramolecular interac-
tions, molecules that form discrete dimers and molecules
that assemble into polymeric chains by intermolecular in-
teractions), depending on the nature of the phosphane
bridging chain. Although complexes with phosphane li-
gands that have restricted rotation due to the small bite
angle between phosphorus atoms (dppip 3, triphos 9) dis-
played intramolecular Au···Au contacts, diphosphanes with
conformationally flexible backbones (dppe 5, dppp 6, dppb
7) crystallise with the alkane chain fully extended and, in
some cases, intermolecular Au···Au interactions link up the
gold complexes to form extended chains (dppe 5). A par-
ticular case is the formation of a dimer through intermo-
lecular interactions for the conformationally inflexible dppa
derivative 4, a fact that could be attributable to packing
forces.
Au1···Au2
Au1–P1
Au1–C11
Au2–P2
Au2–C21
Au3–P3
Au3–C31
C11–C12
C21–C22
C31–C32
3.3772(13)
2.284(2)
2.021(11)
2.299(3)
2.055(15)
2.287(3)
2.011(11)
1.181(16)
1.139(18)
1.204(16)
P1–Au1–C11
Au1–C11–C12
P2–Au2–C21
Au2–C21–C22
C2–P1–Au1
177.1(3)
167.9(12)
177.0(3)
179.5(13)
112.9(3)
116.8(3)
98.3(3)
80.12(6)
103.9(3)
78.33(6)
173.2(3)
166.0(11)
114.6(3)
113.2(8)
C3–P2–Au2
C11–Au1···Au2
P1–Au1···Au2
C21–Au2···Au1
P2–Au2···Au1
P3–Au3–C31
Au3–C31–C32
C4–P3–Au3
C2–C1–C3
The molecular structure of triphos compound 9 (Fig-
ure 8) shows aurophilic contacts [d(Au···Au)
=
3.3772(13) Å] between the gold atoms corresponding to two
of the arms of the triphosphane, whereas the third one lies
apart. This asymmetric disposition is similar to that found
for the closely related compounds [Au3X3(µ3-triphos)] (X =
Cl)[52] (X = Br, I).[53] The crystal packing is determined by
the existence of weak N···Au interactions [3.114(11) Å] be-
tween the nitrogen atom of the pyridine ring that belongs
to one of the arms involved in the intramolecular interac-
tion and the gold atom of a neighbouring molecule not in-
volved in the named interaction. The chains are parallel
to the c axis and are shown in Figure 9. Some reports
can be found where N···Au contacts have a decisive
influence on the lattice organisation; for example, the
compound [AuCl(2-diphenylphosphanylpicolinamide)],[54]
where d(N···Au) = 3.129 Å, adopts a lattice distribution
analogous to that of compound 9 and the complex [Au(tht)2]-
[C6H4NO4S2][55] displays a d(N···Au) = 3.009 Å.
Fortunately, the diversity of the obtained structures of-
fered us a good opportunity to study in detail the photo-
physical properties of the compounds in order to find corre-
lations between the observed absorption and emission
trends and the presence and nature of aurophilic contacts.
Photophysical Studies
The electronic absorption spectra of compounds 1–9
were recorded in dichloromethane solution at room tem-
perature. The results are summarised in Table 7.
All the complexes exhibit intense high-energy absorp-
tions in the range 250–300 nm, which in some cases present
a tail extending to ca. 370 nm. The band at ca. 250 nm,
which is also present in the free diphosphane ligands, has
been assigned as a phosphane-centred intraligand transi-
tion. The intense and vibronically structured electronic ab-
sorption in the range 267–286 nm, with progressional spac-
ings of ca. 1860 cm–1, typical of ν(CϵC) stretching fre-
quencies in the excited state, is assigned to intraligand (IL)
πǞπ* (CϵCpy), as seen in other published works on alk-
ynyl gold(I) phosphane complexes.[25,26,56–58] This attri-
bution is also confirmed by the observation of conforma-
tion-dependent excitonic perturbations (see below).
In order to minimise the possibility of the establishment
of aurophilic intermolecular interactions in solution, ab-
sorption spectra of these complexes (Figure 10a) were car-
ried out at diluted concentrations (10–6 ). Compounds 1–
3, 5–7 and 9, which contain the same chromophoric units
but different numbers of carbon atoms at the alkyl bridging
chain, are expected to present identical absorption spectra,
unless different interactions occur at the molecular level.
Figure 8. Molecular structure of [Au3(CϵCC5H4N)3(µ3-
triphos)](9).
Figure 9. Supramolecular association in 9 through intermolecular N···Au interactions to form an infinite chain.
Eur. J. Inorg. Chem. 2008, 2899–2909
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
2903

M. Ferrer et al.
FULL PAPER
Table 7. Electronic absorption (10–6  freshly prepared dichloromethane solution, room temp.) and emission data in the solid state (room
temp.) for compounds 1–9.
Compound
Absorption data λabs [nm] (10–3 ε, –1 cm–1)
Emission data (λex = 360 nm) λem [nm] (τ, µs)
1
2
3
4
5
6
7
8
9
252 (24.9), 268 (32.6), 282 (35.4)
271 (40.5), 286 sh. (36.0)
272 (43.6), 284 sh. (39.3)
252 sh. (48.7), 268 (56.9), 284 (61.0)
253 (30.8), 267 (49.1), 282 (56.3)
254 (30.5), 267 (54.6), 282 (59.7)
252 (29.8), 268 (56.9), 281 (65.4)
252 (46.1), 268 (57.9), 282 (62.3)
251 (55.4), 268 (77.7), 282 (86.3)
405, 428, 444, 462 (36)
458 (1.1)
420, 440, 458, 516 (1.5)
530 (0.7)
505 (1.2)
407, 427, 442, 547[a] (3.5)
410, 441, 456, 503 (3.5)
nonemissive
508, 570 sh. (1.7)
[a] From gated emission spectra with 50 µs delay after excitation with a pulsed Xenon lamp (ca. 40 µs pulse width).
Although compounds 4 and 8 have additional chromo- bands of compounds 2 and 3 strongly suggests the existence
phores, they do not modify the position of the observed of intramolecular aurophilic interactions that could be re-
bands. Although compounds 1 and 4–8 exhibit identical sponsible for a molecular conformation where the two eth-
features (two well-resolved peaks with maxima at ca. 268 ynylpyridine ligands are close enough to strongly interact
and 282 nm), the corresponding spectra of 2 (dppm) and 3 and undergo exciton splitting. A similar effect was pointed
(dppip) display different characteristics: a broad band with out for other alkynyl gold(I) compounds bearing Au–Au
a maximum at ca. 272 and shoulder at ca. 285 nm with a interactions.[31]
tail at longer wavelengths. A special case is the spectrum of
In the case of compound 9, despite the fact that the UV/
compound 9 (triphos), which seems to present a mixture of Vis spectrum clearly shows an excitonic perturbation, its
both features (representative examples are shown in Fig- interpretation is not straightforward, as its corresponding
1
ure 10b).
NMR spectra (31P, H and 13C), even at low temperature,
It is interesting to notice that compounds 2 and 3 are show the equivalence of the three arms of the triphosphane.
also different from the other compounds in the homochro- The X-ray crystal structure, however, displays an intramo-
mophoric series, as their 13C NMR spectra seem to indicate lecular aurophilic interaction between a pair of gold(I)
the presence of intramolecular aurophilic interactions in atoms.
solution (see above). Moreover, the X-ray crystal structure
of compound 3 shows the presence of a rather short intra- on the nuclearity of the complexes shows that for diphos-
molecular gold–gold contact [3.235(2) Å]. phane compounds 4–8, the molar absorptivities are roughly
Analysis of the dependence of the extinction coefficients
It is well known, for dimers in solution, that interaction twice those of triphenylphosphane compound 1, whereas
between the transition dipoles leads to the appearance of for 2 and 3 the values are slightly lower, as expected for
new excitonic transitions and a consequent broadening of the observed excitonic broadening. The latter effect is also
the absorption spectra when compared to monomer ab- observed for triphos compound 9, whose extinction coeffi-
sorption.[59] The observed broadening in the absorption cients are a bit lower than the expected triple.
Figure 10. (a) Electronic absorption spectra of compounds 1–9 in dichloromethane (10–6 ), (b) normalised electronic absorption spectra
of compounds 1 (solid line), 2 (dashed line) and 9 (dotted line) in dichloromethane.
2904
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 2899–2909

Effects of the Phosphane Bridging Chain on AuI Complexes
The emission of the complexes in dichloromethane solu- and 5. Compounds 3 and 7 present similar contributions of
tion is very weak and the compounds undergo rapid photo- these two bands (see Supporting Information). Figure 11
decomposition during the tracing of the emission spectrum. shows illustrative examples of the different emission pat-
This behaviour was also reported for other alkynyl gold(I) terns. In fact, the phosphorescence spectrum of compound
complexes.[9]
6, collected with a delay between excitation and emission of
The excitation of the solids with λ = 360 nm at room 50 µs, is completely different from the one obtained without
temperature produces intense emission bands between 425 delay showing a broad emission band centred at 547 nm
and 570 nm (Table 7) for compounds 1–7 and 9, whereas instead of the high-energy structured band (Figure 12).
the luminescence of compound 8 is strongly quenched by
the presence of the ferrocenyl group.[50,57,60] The observed
large Stokes shifts suggest a triplet parentage for the excited
state and, therefore, phosphorescence emissions. The band
at higher energies (in the range 425–458 nm) displays a well-
defined vibrational structure, whereas the band at lower en-
ergies (in the range 500–570 nm) presents a broad structure-
less shape (Figure 11). This fact together with the difference
in the excitation spectra monitored at the high- and low-
energy emission bands are indicative of different origins for
the corresponding emissions.
Figure 12. Time-gated emission spectra (normalised) of compound
6 (solid) recorded at room temperature: without delay time (solid
line) and with 50 µs delay after excitation (dashed line).
Compound 9 is a particular case because the low-energy
transition is split into two broad emission bands at 508 and
570 nm that we suspect to correlate with two different envi-
ronments of gold atoms. This is in agreement with the X-
ray data, which show intramolecular aurophilic interaction
between two of the three arms; a fact that could have an
influence on the emission.
Our results seems to indicate that aurophilic interactions
are not a prerequisite for the observation of a broad emis-
sion band at lower energies, as the spectra of dppip deriva-
tive 3 and dppb derivative 7, whose X-ray structures show
intramolecular and no gold–gold contacts, respectively,
show similar profiles. At the same time, careful analysis of
the emission spectra does not show any correlation between
the existence of gold–gold contacts and the position and/or
the intensity of the emission bands.[50,62]
Figure 11. Solid-state emission spectra of compounds 1 (dotted
line), 3 (solid line) and 4 (dashed line) upon excitation at λ =
360 nm at room temperature.
The excitation spectra monitored at the high-energy
emission bands reproduces absorption spectra bands in the
range 250–300 nm, which is consistent with an emission of
ligand-centred origin. Moreover, the vibronic structure of
these bands is also indicative of the involvement of the li-
gands in the transition. Thus, by comparison with the lit-
erature,[26,57] we assign the high-energy emission band dis-
played by our complexes to an intraligand 3[π-π*(alkynyl)]
emission.
Conclusions
We report here the synthesis and characterisation of new
In contrast, excitation spectra collected for all the com- alkynyl gold(I) phosphane compounds derived from the
pounds at 500–600 nm display a band at ca. 360 nm (Stokes ethynylpyridine. The use of phosphanes with different car-
shift ca. 8000 cm–1), which is not clearly visible in the ab- bon-chain features allowed us to structurally characterise a
sorption spectra of diluted solutions collected in 1-cm path series of compounds that adopt a wide variety of structural
cells. However, absorption spectra of the same solutions ob- motifs, which, in some cases, are the result of the establish-
tained in 10 cm path cells clearly display the 360 nm absorp- ment of intra- or intermolecular aurophilic interactions.
tion band. These broad emissions are usually assigned as
From the photophysical measurements, it was found that
derived from the 3[σ(Au–P)Ǟπ*(CϵCpy)] excited absorption band broadening could be indicative of the exis-
state,[6,25,57] although a contribution of Au-centred states to tence of intramolecular aurophilic interactions in solution.
their origin should not be ruled out.[11,56,58,61]
In contrast, the emission and excitation spectra of the com-
The two emission bands present different proportions de- plexes in the solid state did not display significant differ-
pending on the complex. Although for compounds 1 and 6 ences, independently of the presence or absence of either
the structured band is predominant, the broad band at intra- or intermolecular gold–gold interactions. As a conse-
lower energy dominates the emission of compounds 2, 4 quence, we can conclude that there is not a straightforward
Eur. J. Inorg. Chem. 2008, 2899–2909
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
2905

M. Ferrer et al.
FULL PAPER
[Au2(CϵCC5H4N)2(µ2-dppip)] (3): Derivative 3 was prepared ac-
cording to the procedure outlined for 2. Yield: 65 mg, 80%. 1H
NMR (400.1 MHz, CDCl3): δ = 8.35 (d, J = 6.0 Hz, 4 H, Hα-pyr),
7.92–7.39 (m, 24 H, PPh2, Hβ-pyr), 1.70 [t, J = 14.8 Hz, 6 H, P-
relation between the existence of Au···Au interactions and
the occurrence and/or characteristics of the broad low-en-
ergy emission band displayed by alkynyl gold(I) phosphane
complexes.
C(CH3)2-P] ppm. 13C{1H} NMR (100.0 MHz, CDCl3): δ = 149.3
(s, Cα-pyr), 140.8 (AXXЈ m, 2Jcalcd. ≈ 150 Hz,
J
calcd.
≈ –15 Hz, P-
3+4
Au-CϵC), 136.4 (t, Cortho Ph), 134.0 (s, Cγ-pyr), 132.4 (s, Cpara Ph),
Experimental Section
129.2 (t, Cmeta Ph), 127.0 (t, Cipso Ph), 126.8 (s, Cβ-pyr), 102.4 (AXXЈ
3+4
t, 2Jcalcd. ≈ 20 Hz,
J
calcd.
≈ 2 Hz, P-Au-CϵC), 40.3 [t, J = 22 Hz,
General Procedures: All manipulations were performed under pre-
purified N2 by using standard Schlenk techniques. All solvents were
distilled from appropriate drying agents. Commercial reagents
PPh3, dppa, dppbz, dppf, dppp and 4-bromopyridine hydrochlo-
ride were used as received. Literature methods were used to prepare
[AuCl(tht)],[63] [Au(CϵCC5H4N)]n,[4] NC5H4CϵCH,[64] dppm,[65]
dppip,[32] dppe[65] and dppb.[65]
P-C(CH3)2-P], 25.1 [s, P-C(CH3)2-P] ppm. 31P{1H} NMR
(101.2 MHz, CDCl ): δ = 56.7 (s, dppip) ppm. IR (KBr): ν = 2120
˜
3
(CϵC) cm–1. MS (ESI): m/z = 1011.4 [M + H]+, 506.2 [M +
2H]2+. C41H34Au2N2P2 (1010.61): calcd. C 48.73, H 3.39, N 2.77;
found C 48.77, H 3.45, N 2.83.
[Au2(CϵCC5H4N)2(µ2-dppa)] (4): Derivative 4 was prepared ac-
cording to the procedure outlined for 2. Yield: 50 mg, 63%. 1H
NMR (400.1 MHz, CDCl3): δ = 8.49 (d, J = 6.0 Hz, 4 H, Hα-pyr),
7.76–7.46 (m, 20 H, PPh2), 7.30 (d, J = 6.0 Hz, 4 H, Hβ-pyr) ppm.
13C{1H} NMR (100.0 MHz, CDCl3): δ = 149.6 (s, Cα-pyr), 136.5 (s,
P-Au-CϵC), 133.4 (d, J = 16 Hz, Cortho Ph), 132.9 (s, Cγ-pyr), 132.4
(d, J = 2 Hz, Cpara Ph), 129.8 (d, J = 12 Hz, Cmeta Ph), 128.6 (d, J
= 53 Hz, Cipso Ph), 126.6 (s, Cβ-pyr), 102.5 (br. d, J = 16 Hz P-
CϵC-P), 101.6 (s, P-Au-CϵC) ppm. 31P{1H} NMR (101.2 MHz,
CDCl3): δ = 16.6 (s, dppa) ppm. C40H28Au2N2P2 (992.56): calcd.
C 48.40, H 2.84, N 2.82; found C 48.41, H 2.91, N 2.87. IR (KBr):
Physical Measurements: Infrared spectra were recorded with a
FTIR 520 Nicolet spectrophotometer. 1H NMR [δ(TMS) =
0.0 ppm], 31P{1H} NMR [δ(85% H3PO4) = 0.0 ppm] and 13C{1H}
NMR [δ(TMS) = 0.0 ppm] spectra were obtained with a Varian
Unity 400 and Bruker DXR 250 spectrometers at 25 °C unless
otherwise stated. The g-NMR software package was used to simu-
late NMR spectroscopic data. Elemental analyses of C, H and N
were carried out at the Serveis Científico-Tècnics in Barcelona. MS
(ESI) spectra were recorded with a Fisons VG Quatro spectrometer.
Absorption spectra were recorded with a Shimadzu UV-2501PC
spectrophotometer and emission spectra with a Horiba-Jobin–
Yvon SPEX Fluorolog 3.22 spectrofluorimeter. The decay times of
the powders were measured with a laser flash photolysis LK60 Ap-
plied Photophysics system in emission mode, collecting the decay
at 550 nm after laser pulse excitation at 355 nm.
ν = 2120 (CϵC) cm–1. MS (ESI): m/z = 993.1 [M + H]+, 497.2 [M
˜
+ 2H]2+
.
[Au2(CϵCC5H4N)2(µ2-dppe)] (5): Derivative 5 was prepared ac-
cording to the procedure outlined for 2. Yield: 60 mg, 75%. 1H
NMR (400.1 MHz, CDCl3): δ = 8.47 (d, J = 5.6 Hz, 4 H, Hα-pyr),
7.65–7.44 (m, 20 H, PPh2), 7.30 (d, J = 6.0 Hz, 4 H, Hβ-pyr), 2.65
(s, 4 H, P-CH2CH2-P) ppm. 13C{1H} NMR (100.0 MHz, CDCl3):
δ = 149.7 (s, Cα-pyr), 140.3 (br. d, J = 142 Hz, P-Au-CϵC), 133.6
(t, Cortho Ph), 133.1 (s, Cγ-pyr), 132.6 (s, Cpara Ph), 129.8 (t, Cmeta
Ph), 128.7 (t, Cipso Ph), 126.7 (Cβ-pyr), 101.8 (br. s, P-Au-CϵC),
24.2 (t, P-CH2CH2-P) ppm. 31P{1H} NMR (101.2 MHz, CDCl3):
δ = 40.1 (s, dppe) ppm. C40H32Au2N2P2 (996.59): calcd. C 48.21,
[Au(CϵCC5H4N)(PPh3)] (1): To a suspension of [Au(CϵCC5H4N)]n
(50 mg, 0.17 mmol) in CH2Cl2 (15 mL) was added solid PPh3
(44 mg, 0.17 mmol), and the mixture was stirred for 1 h and then
filtered through Celite. The resulting solution was concentrated
(5 mL) and diethyl ether (10 mL) was added to precipitate a white
1
solid. Yield: 80 mg, 85%. H NMR (400.1 MHz, CDCl3): δ = 8.47
(d, J = 5.6 Hz, 2 H, Hα-pyr), 7.57–7.45 (m, 15 H, PPh3), 7.32 (d, J
= 6.0 Hz, 2 H, Hβ-pyr) ppm. 13C{1H} NMR (100.0 MHz, CDCl3):
δ = 149.5 (s, Cα-pyr), 134.4 (d, J = 14 Hz, Cortho Ph), 133.2 (s, Cγ-
pyr), 131.8 (s, J = 2 Hz, Cpara Ph), 129.5 (d, J = 56 Hz, Cipso Ph),
129.3 (d, J = 11 Hz, Cmeta Ph), 126.6 (s, Cβ-pyr), 101.5 (s, P-Au-
CϵC) ppm. 31P{1H} NMR (101.2 MHz, CDCl3): δ = 42.5 (s, PPh3)
ppm. C25H19AuNP (561.37): calcd. C 53.49, H 3.41, N 2.50; found
H 3.24, N 2.81; found C 48.28, H 3.29, N 2.86. IR (KBr): ν = 2117
˜
(CϵC) cm–1. MS (ESI): m/z = 997.1 [M + H]+, 499.1 [M + 2H]2+
.
[Au2(CϵCC5H4N)2(µ2-dppp)] (6): Derivative 6 was prepared ac-
cording to the procedure outlined for 2. Yield: 65 mg, 80%. 1H
NMR (400.1 MHz, CDCl3): δ = 8.49 (d, J = 6.0 Hz, 4 H, Hα-pyr),
7.72–7.42 (m, 20 H, PPh2), 7.30 (d, J = 6.0 Hz, 4 H, Hβ-pyr), 2.84
(m, 4 H, P-CH2-CH2-CH2-P), 1.95 (m, 2 H, P-CH2-CH2-CH2-P)
ppm. 13C{1H} NMR (100.0 MHz, CDCl3): δ = 149.7 (s, Cα-pyr),
140.1 (d, J = 140 Hz, P-Au-CϵC), 133.7 (d, J = 13 Hz, Cortho Ph),
133.4 (s, Cγ-pyr), 132.1 (d, J = 2 Hz Cpara Ph), 129.6 (d, J = 11 Hz,
Cmeta Ph), 129.5 (d, J = 54 Hz, Cipso Ph), 126.6 (s, Cβ-pyr), 101.9 (d,
C 53.57, H 3.31, N 2.55. IR (KBr): ν = 2120 (CϵC) cm–1. MS
˜
(ESI): m/z = 562.1 [M + H]+.
[Au2(CϵCC5H4N)2(µ2-dppm)] (2): To
a
suspension of
[Au(CϵCC5H4N)]n (50 mg, 0.17 mmol) in CH2Cl2 (15 mL) was
added solid dppm (32 mg, 0.08 mmol), and the mixture was stirred
for 1 h and then filtered through Celite. The resulting solution was
concentrated (5 mL) and n-hexane (20 mL) was added to precipi-
tate a white solid. The compound was recrystallised from CH2Cl2/
1
3
J = 26 Hz, P-Au-CϵC), 28.9 (dd, J = 34 Hz, J = 11 Hz, P-CH2-
CH2-CH2-P), 20.3 (t, J = 4 Hz, P-CH2-CH2-CH2-P) ppm. 31P{1H}
NMR (101.2 MHz, CDCl3):
δ
=
32.4 (s, dppp) ppm.
1
n-hexane. Yield: 60 mg, 73%. H NMR (400.1 MHz, CDCl3): δ =
C41H34Au2N2P2 (1010.61): calcd. C 48.73, H 3.39, N 2.77; found
8.35 (d, J = 5.2 Hz, 4 H, Hα-pyr), 7.65–7.33 (m, 20 H, PPh2), 7.25
(d, J = 5.2 Hz, 4 H, Hβ-pyr), 3.60 (t, J = 10.9 Hz, 2 H, P-CH2-P)
ppm. 13C{1H} NMR (100.0 MHz, CDCl3): δ = 149.4 (s, Cα-pyr),
C 48.61, H 3.41, N 2.81. IR (KBr): ν = 2120 (CϵC) cm–1. MS
˜
(ESI): m/z = 1011.2 [M + H]+, 506.1 [M + 2H]2+
.
2
3+4
140.5 (AXXЈ m, Jcalcd. ≈ 140 Hz,
J
calcd.
≈ 4 Hz, P-Au-CϵC), [Au2(CϵCC5H4N)2(µ2-dppb)] (7): Derivative 7 was prepared ac-
133.6 (t, Cortho Ph), 132.6 (s, Cγ-pyr), 132.4 (s, Cpara Ph), 129.6 (s, cording to the procedure outlined for 2. Yield: 70 mg, 85%. 1H
Cmeta Ph), 129.2 (t, Cipso Ph), 126.7 (s, Cβ-pyr), 102.5 (AXXЈ t, NMR (400.1 MHz, CDCl3): δ = 8.49 (d, J = 6.0 Hz, 4 H, Hα-pyr),
4+5
3Jcalcd. ≈ 20 Hz,
J
≈ 3 Hz, P-Au-CϵC), 29.7 (t, J = 26 Hz, 7.67–7.44 (m, 20 H, PPh2), 7.32 (d, J = 6.0 Hz, 4 H, Hβ-pyr), 2.41
calcd.
P-CH2-P) ppm. 31P{1H} NMR (101.2 MHz, CDCl3): δ = 30.8 (s,
[m, 4 H, P-CH2-(CH2)2-CH2-P], 1.79 [m, 4 H, P-CH2-(CH2)2-CH2-
d) ppm. IR (KBr): ν = 2107 (CϵC) cm–1. MS (ESI): m/z = 983.1
P] ppm. 13C{1H} NMR (100.0 MHz, CDCl3): δ = 149.7 (s, Cα-pyr),
˜
[M + H]+, 492.3 [M + 2H]2+. C39H30Au2N2P2 (982.56): calcd. C 140.4 (d, J = 141 Hz, P-Au-CϵC), 133.5 (d, J = 13 Hz, Cortho Ph),
47.67, H 3.08, N 2.85; found C 47.71, H 3.11, N 2.90.
2906
133.3 (s, Cγ-pyr), 132.1 (s, Cpara Ph), 129.9 (d, J = 60 Hz, Cipso Ph),
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 2899–2909

Effects of the Phosphane Bridging Chain on AuI Complexes
129.6 (d, J = 11 Hz, Cmeta Ph), 126.7 (s, Cβ-pyr), 101.6 (d, J = 26 Hz,
CDCl3): δ = 8.48 (d, J = 5.6 Hz, 6 H, Hα-pyr), 7.89–7.41 (m, 30 H,
P-Au-CϵC), 28.0 [d, J = 34 Hz, P-CH2-(CH2)2-CH2-P], 27.3 [d, J PPh2), 7.22 (d, J = 6.0 Hz, 6 H, Hβ-pyr), 3.40 (d, J = 10.8 Hz, 6 H,
= 17 Hz, P-CH2-(CH2)2-CH2-P] ppm. 31P{1H} NMR (101.2 MHz,
CDCl3): δ = 37.4 (s, dppb) ppm. C42H36Au2N2P2 (1024.64): calcd.
C 49.23, H 3.54, N 2.73; found C 49.31, H 3.51, N 2.79. IR (KBr):
CH2), 0.85 (s, 3 H, CH3) ppm. 13C{1H} NMR (100.0 MHz,
CDCl3): δ = 149.7 (s, Cα-pyr), 139.5 (d, J = 139 Hz, P-Au-CϵC),
134.1 (d, J = 14 Hz, Cortho Ph), 133.3 (s, Cγ-pyr), 132.2 (s, Cpara Ph),
ν = 2120 (CϵC) cm–1. MS (ESI): m/z = 1025.1 [M + H]+, 513.2 130.9 (d, J = 55 Hz, Cipso Ph), 129.7 (d, J = 11 Hz, Cmeta Ph), 126.6
˜
[M + 2H]2+
.
(s, Cβ-pyr), 101.9 (d, J = 26 Hz, P-Au-CϵC), 42.9 (dt, J = 30 Hz,
1
2
3J = 7 Hz, CH2), 39.0 (s, CH3), 30.9 (q, J = 6 Hz, C-CH3) ppm.
31P{1H} NMR (101.2 MHz, CDCl3): δ = 25.5 (s, triphos) ppm. IR
[Au2(CϵCC5H4N)2(µ2-dppf)] (8): Derivative 8 was prepared accord-
(KBr): ν = 2120 (CϵC) cm–1. MS (ESI): m/z = 1523.1 [M + H]+,
1
˜
ing to the procedure outlined for 2. Yield: 65 mg, 70%. H NMR
761.9 [M + 2H]2+, 508.3 [M + 3H]3+. C62H51Au3N3P3 (1521.23):
calcd. C 48.93, H 3.38, N 2.76; found C 48.96, H 3.41, N 2.80.
(400.1 MHz, CDCl3): δ = 8.48 (d, J = 6.4 Hz, 4 H, Hα-pyr), 7.56–
7.40 (m, 20 H, PPh2), 7.32 (d, J = 6.4 Hz, 4 H, Hβ-pyr), 4.72 (br. s,
4 H, 2,5-H C5H4), 4.33 (br. s, 4 H, 3,4-H C5H4) ppm. 13C{1H}
NMR (100.0 MHz, CDCl3): δ = 149.7 (s, Cα-pyr), 139.5 (d, J =
144 Hz, P-Au-CϵC), 133.8 (d, J = 14 Hz, Cortho Ph), 133.4 (s,
[Au(dppbz)2] [Au(CϵCC5H4N)2] (10): To
a
suspension of
[Au(CϵCC5H4N)]n (50 mg, 0.17 mmol) in CH2Cl2 (15 mL) was
added solid dppbz (75 mg, 0.17 mmol), and the mixture was stirred
for 1 h and then filtered through Celite. The resulting solution was
concentrated (5 mL) and diethyl ether (20 mL) was added to pre-
Cγ-pyr), 131.8 (s, J = 2 Hz, Cpara Ph), 131.2 (d, J = 58 Hz, Cipso Ph),
129.3 (d, J = 11 Hz, Cmeta Ph), 126.7 (s, Cβ-pyr), 101.8 (d, J = 27 Hz,
P-Au-CϵC), 75.2 (s, C-3,4 C5H4), 75.1 (d, J = 5 Hz, C-2,4 C5H4),
72.1 (d, J = 64 Hz, C-1 C5H4) ppm. 31P{1H} NMR (101.2 MHz,
1
cipitate a yellow solid. Yield: 80 mg, 63%. H NMR (400.1 MHz,
CDCl3): δ = 8.29 (d, J = 5.2 Hz, 4 H, Hα-pyr), 7.54–7.43 (m, 8 H,
P-C6H4-P), 7.32 (m, 8 H, Hpara PPh2), 7.23 (d, J = 5.6 Hz, 4 H,
CDCl ): δ = 36.9 (s, dppf) ppm. IR (KBr): ν = 2120 (CϵC)
˜
3
cm–1. MS (ESI): m/z = 1153.0 [M + H]+, 577.2 [M + 2H]2+
.
H
β-pyr), 7.10–7.00 (m, 32 H, Hmeta+ortho PPh2) ppm. 13C{1H} NMR
C48H36Au2FeN2P2 (1152.55): calcd. C 50.02, H 3.15, N 2.43; found
C 50.11, H 3.19, N 2.53.
(100.0 MHz, CDCl3): δ = 149.1 (s, Cα-pyr), 142.2 (AXXЈXЈЈ2 m,
2
1Jcalcd. ≈ 35 Hz, Jcalcd. ≈ 4 Hz, Cipso P-C6H4-P), 135.9 (s, Cγ-pyr),
134.4 (m, C-3,4 P-C6H4-P), 132.6 (AXXЈXЈЈ2 m, Cipso PPh2), 132.4
(m, Cortho PPh2), 131.8 (s, C-5,6 P-C6H4-P), 130.5 (s, Cpara PPh2),
129.2 (m, Cmeta PPh2), 127.0 (s, Cβ-pyr), 100.9 (s, P-Au-CϵC) ppm.
31P{1H} NMR (101.2 MHz, CDCl3): δ = 21.7 (s, dppbz) ppm. IR
[Au3(CϵCC5H4N)3(µ3-triphos)] (9): To
a
suspension of
[Au(CϵCC5H4N)]n (50 mg, 0.17 mmol) in CH2Cl2 (15 mL) was
added solid triphos (31 mg, 0.05 mmol), and the mixture was
stirred for 1 h and then filtered through Celite. The resulting solu-
tion was concentrated (5 mL) and n-hexane (20 mL) was added to
precipitate a white solid. The compound was recrystallised from
CH2Cl2/n-hexane. Yield: 60 mg, 79%. 1H NMR (400.1 MHz,
(KBr): ν = 2103 (CϵC) cm–1. MS (ESI+): m/z (%) = 1089.2
˜
[Au(dppbz)2]+. MS (ESI–): m/z (%) = 401.3 [Au(CϵCC5H4N)2]–.
C74H58Au2N2P4 (1493.12): calcd. C 59.53, H 3.91, N 1.88; found
C 59.59, H 3.94, N 1.91.
Table 8. Crystal and structure determination data.
Compound
3
4
5·0.5CHCl3
Empirical formula
Formula weight
C41H34Au2N2P2
1010.58
C80H56Au4N4P4
1985.03
C40H32Au2N2P2
1056.23
Temperature [K]
Wavelength [Å]
293(2)
0.71073
293(2)
0.71073
293(2)
0.71073
Crystal system
Space group
triclinic
P1
triclinic
P1
triclinic
P1
¯
¯
¯
a [Å]
b [Å]
11.315(5)
14.579(16)
12.546(7)
12.882(5)
12.622(9)
13.086(13)
c [Å]
α [°]
22.790(5)
81.34(4)
12.987(7)
87.34(3)
14.774(4)
112.61(4)
β [°]
82.50(3)
71.70(6)
3515(4)
70.99(3)
61.330(2)
1725.8(15)
93.52(4)
114.42(6)
1979(2)
γ [°]
V [Å3]
Z
4
1
2
Dcalcd. [Mgm–3]
Absorption coefficient [mm1]
F(000)
1.910
8.462
1928
1.910
8.615
940
1.772
7.615
1006
Crystal size [mm]
θ range for data collection [°]
Index ranges
0.09ϫ0.05ϫ0.05
2.03–29.97
–15ՅhՅ15
–20ՅkՅ20
0ՅlՅ32
0.2ϫ0.1ϫ0.1
2.63–30.00
–16ՅhՅ17
–17ՅkՅ17
0ՅlՅ18
0.2ϫ0.1ϫ0.1
2.07–29.96
–17ՅhՅ17
–18ՅkՅ16
0ՅlՅ20
Reflections collected/unique
Refinement method
20429/20492 [Rint = 0.0180]
full-matrix least-squares on F2
20429/0/851
12217/8202 [Rint = 0.0609]
full-matrix least-squares on F2
8202/0/416
11474/11474 [Rint = 0.0000]
full-matrix least-squares on F2
11474/6/379
0.859
R1 = 0.0484, wR2 = 0.1091
R1 = 0.1826, wR2 = 0.1479
0.947 and –0.824
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [IϾ2σ(I)]
R indices (all data)
0.908
1.125
R1 = 0.0516, wR2 = 0.1174
R1 = 0.1326, wR2 = 0.1449
R1 = 0.0616, wR2 = 0.1808
R1 = 0.0862, wR2 = 0.1978
0.950 and –0.856
Largest diff. peak and hole [eÅ–3] 0.824 and –0.979
Eur. J. Inorg. Chem. 2008, 2899–2909
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
2907

M. Ferrer et al.
FULL PAPER
Table 9. Crystal and structure determination data.
Compound
6
7·4CH2Cl2·2H2O
9·3.5CH2Cl2
Empirical formula
Formula weight
Temperature [K]
C41H34Au2N2P2
1010.58
293(2)
C42H36Au2N2P2
1400.34
193(2)
C62H51Au3N3P3
1819.11
193(2)
Wavelength [Å]
Crystal system
Space group
0.71073
0.71073
0.71073
monoclinic
P21/c
triclinic
triclinic
¯
¯
P1
P1
a [Å]
b [Å]
c [Å]
α [°]
26.381(15)
6.845(4)
23.218(7)
90
8.692(5)
12.475(5)
13.937(5)
65.24(2)
14.102(6)
14.755(6)
33.292(7)
90
β [°]
117.64(2)
90
3714(3)
4
1.807
8.007
1928
75.72(3)
71.00(3)
1286.8(10)
1
1.807
6.210
678
100.201(3)
90
6818(4)
4
1.772
6.825
γ [°]
V [Å3]
Z
Dcalcd. [Mgm–3]
Absorption coefficient [mm1]
F(000)
3492
Crystal size [mm]
θ range for data collection [°]
Index ranges
0.2ϫ0.1ϫ0.1
3.11–29.99
–33ՅhՅ34
–7ՅkՅ8
–31ՅlՅ29
12464/4041 [Rint = 0.0355]
full-matrix least-squares on F2
4041/0/213
0.2ϫ0.1ϫ0.1
1.62–29.99
0.2ϫ0.1ϫ0.1
2.56–30.00
–19ՅhՅ19
0ՅkՅ19
0ՅlՅ46
14839/14839 [Rint = 0.0438]
full-matrix least-squares on F2
14839/6/749
–10ՅhՅ11
–15ՅkՅ17
0ՅlϽՅ18
6173/6173 [Rint = 0.0451]
full-matrix least-squares on F2
6173/9/298
Reflections collected/unique
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [IϾ2σ(I)]
R indices (all data)
1.135
1.120
1.110
R1 = 0.0383, wR2 = 0.1062
R1 = 0.0413, wR2 = 0.1087
R1 = 0.0425, wR2 = 0.1269
R1 = 0.0490, wR2 = 0.1387
0.903 and –0.845
R1 = 0.0620, wR2 = 0.1740
R1 = 0.0979, wR2 = 0.1976
0.989 and –0.856
Largest diff. peak and hole [eÅ–3] 0.826 and –0.701
X-ray Crystallography: A prismatic crystal of 4, 6, 7 or 9 was se-
lected and mounted on a MAR345 diffractometer with an image
plate detector. Reflection data for 3 and 5 were collected with an
Enraf–Nonius CAD4 four-cycle diffractometer. The reflections
were assumed as observed by applying the condition IϾ2σ(I). In-
tensities were collected with graphite monochromated Mo-Kα radi-
ation. Three reflections were measured every 2h as orientation and
intensity control, significant intensity decay was not observed. Lo-
rentz polarisation and absorption corrections were made. The
structures were solved by direct methods with the use of the
SHELXS computer program[66] and refined by full-matrix least-
squares method with the SHELX97 computer program[67] (very
negative intensities were not assumed). The function minimised was
Σw||Fo|2–|Fc|2|2, where w = [σ2(I) + (0.0760P)2]–1 (for 3), w = [σ2(I)
+ (0.1217P)2]–1 (for 4), w = [σ2(I) + (0.0616P)2 + 7.8257P]–1 (for
6), w = [σ2(I) + (0.0694P)2 + 1.5419P]–1 (for 7), w = [σ2(I) +
(0.1034P)2]–1 (for 9) and w = [σ2(I) + (0.0718P)2]–1 (for 5); P =
(|Fo|2 + 2|Fc|2)/3, f, fЈ and fЈЈ were taken from International Tables
of X-ray Crystallography.[68] The Final R values as well as further
details concerning the resolution and refinement of the all struc-
tures are presented in Tables 8 and 9.
Acknowledgments
Financial support for this work was provided by the Ministerio
de Educación y Ciencia (Project CTQ2006–02362/BQU), Acción
Integrada Hispano-Portuguesa (HP2006-0101) and Acção Inte-
grada Luso-Espanhola (E-68/07L). L. R. and A. G. thank Fun-
daçao para Ciência e Tecnologia for a post-doctoral grant (Portu-
gal, SFRH/BPD/26882/2006) and the Universitat de Barcelona for
a scholarship, respectively.
[1]
[2]
M. P. Cifuentes, M. G. Humphrey, J. Organomet. Chem. 2004,
689, 3968–3981.
J. Vicente, M. T. Chicote, M. D. Abrisqueta, M. C. R. de Arel-
lano, P. G. Jones, M. G. Humphrey, M. P. Cifuentes, M. Sa-
moc, B. Luther-Davies, Organometallics 2000, 19, 2968–2974.
[3]
[4]
S. K. Hurst, M. P. Cifuentes, A. M. McDonagh, M. G. Hum-
phrey, M. Samoc, B. Luther-Davies, I. Asselberghs, A. Per-
soons, J. Organomet. Chem. 2002, 642, 259–267.
M. Ferrer, M. Mounir, L. Rodriguez, O. Rossell, S. Coco, P.
Gomez-Sal, A. Martin, J. Organomet. Chem. 2005, 690, 2200–
2208.
CCDC-676516 (for 3), -676518 (for 4), -676517 (for 5), -676519 (for
6), -676515 (for 7) and -677298 (for 9) contain the supplementary
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.
[5]
[6]
P. Espinet, Gold Bull. 1999, 32, 127–134.
V. W. W. Yam, K. M. C. Wong, Top. Curr. Chem. 2005, 257, 1–
32.
A. Vogler, H. Kunkely, Coord. Chem. Rev. 2001, 219, 489–507.
V. W. W. Ya m , K . K . W. L o, Chem. Soc. Rev. 1999, 28, 323–
334.
[7]
[8]
Supporting Information Available (see footnote on the first page of
this article): Solid-state emission spectra of all compounds.
[9]
S. K. Yip, W. H. Lam, N. Y. Zhu, V. W. W. Yam, Inorg. Chim.
Acta 2006, 359, 3639–3648.
2908
www.eurjic.org
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Eur. J. Inorg. Chem. 2008, 2899–2909

Effects of the Phosphane Bridging Chain on AuI Complexes
[10] M. I. Bruce, M. Jevric, B. W. Skelton, M. E. Smith, A. H.
White, N. N. Zaitseva, J. Organomet. Chem. 2006, 691, 361–
370.
[11] M. C. Lagunas, C. M. Fierro, A. Pintado-Alba, H. de la Riva,
S. Betanzos-Lara, Gold Bull. 2007, 40, 135–141.
[12] P. Li, B. Ahrens, A. D. Bond, J. E. Davies, O. F. Koentjoro,
P. R. Raithby, S. J. Teat, Dalton Trans. 2008, 1635–1643.
[13] R. J. Puddephatt, Coord. Chem. Rev. 2001, 216, 313–332.
[14] T. J. Burchell, M. C. Jennings, R. J. Puddephatt, Inorg. Chim.
Acta 2006, 359, 2812–2818.
[15] W. J. Hunks, J. Lapierre, H. A. Jenkins, R. J. Puddephatt, J.
Chem. Soc. Dalton Trans. 2002, 2885–2889.
[16] J. Vicente, M. T. Chicote, M. M. Alvarez-Falcon, D. Bautista,
Organometallics 2004, 23, 5707–5712.
[42]
[43]
T. L. Stott, M. O. Wolf, B. O. Patrick, Inorg. Chem. 2005, 44,
620–627.
S. Onaka, M. Yaguchi, R. Yamauchi, T. Ozeki, M. Ito, T. Sun-
ahara, Y. Sugiura, M. Shiotsuka, M. Horibe, K. Okazaki, A.
Iida, H. Chiba, K. Inoue, H. Imai, K. Sako, J. Organomet.
Chem. 2005, 690, 57–68.
S. C. F. Kui, J. S. Huang, R. W. Y. Sun, N. Y. Zhu, C. M. Che,
Angew. Chem. Int. Ed. 2006, 45, 4663–4666.
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. 1993, 32, 2506–2517.
M. C. Brandys, M. C. Jennings, R. J. Puddephatt, J. Chem. Soc.
Dalton Trans. 2000, 4601–4606.
B. C. Tzeng, A. Schier, H. Schmidbaur, Inorg. Chem. 1999, 38,
3978–3984.
U. E. I. Horvath, S. Cronje, J. M. McKenzie, L. J. Barbour,
H. G. Raubenheimer, Z. Naturforsch., B: Chem. Sci. 2004, 59,
1605–1617.
L. L. Marques, G. Manzoni de Oliveira, E. Schulz Lang, R. A.
Burrow, Z. Naturforsch., B: Chem. Sci. 2005, 60, 318–321.
S. Y. Ho, E. C. C. Cheng, E. R. T. Tiekink, V. W. W. Yam, In-
org. Chem. 2006, 45, 8165–8174.
P. M. VanCalcar, M. M. Olmstead, A. L. Balch, Inorg. Chem.
1997, 36, 5231–5238.
M. K. Cooper, K. Henrick, M. Mcpartlin, J. L. Latten, Inorg.
Chim. Acta 1982, 65, L185–L186.
P. Sevillano, M. E. Garcia, A. Habtemariam, S. Parsons, P. J.
Sadler, Met.-Based Drugs 1999, 6, 211–221.
H. L. Milton, M. V. Wheatley, A. M. Z. Slawin, J. D. Woollins,
Polyhedron 2004, 23, 3211–3220.
[44]
[45]
[46]
[47]
[48]
[17] J. Vicente, M. T. Chicote, M. M. Alvarez-Falcon, P. G. Jones,
Organometallics 2005, 24, 5956–5963.
[18] N. C. Habermehl, M. C. Jennings, C. P. McArdle, F. Mohr,
R. J. Puddephatt, Organometallics 2005, 24, 5004–5014.
[19] N. C. Habermehl, F. Mohr, D. J. Eisler, M. C. Jennings, R. J.
Puddephatt, Can. J. Chem. 2006, 84, 111–123.
[49]
[50]
[51]
[52]
[53]
[54]
[55]
[56]
[57]
[58]
[59]
[20] H. S. Tang, N. Y. Zhu, V. W. W. Yam, Organometallics 2007,
26, 22–25.
[21] C. P. McArdle, M. J. Irwin, M. C. Jennings, J. J. Vittal, R. J.
Puddephatt, Chem. Eur. J. 2002, 8, 723–734.
[22] C. P. McArdle, S. Van, M. C. Jennings, R. J. Puddephatt, J.
Am. Chem. Soc. 2002, 124, 3959–3965.
[23] F. Mohr, D. J. Eisler, C. P. McArdle, K. Atieh, M. C. Jennings,
R. J. Puddephatt, J. Organomet. Chem. 2003, 670, 27–36.
[24] N. C. Habermehl, D. J. Eisler, C. W. Kirby, N. L. S. Yue, R. J.
Puddephatt, Organometallics 2006, 25, 2921–2928.
[25] K. L. Cheung, S. K. Yip, V. W. W. Yam, J. Organomet. Chem.
2004, 689, 4451–4462.
[26] H. Y. Chao, W. Lu, Y. Q. Li, M. C. W. Chan, C. M. Che, K. K.
Cheung, N. Y. Zhu, J. Am. Chem. Soc. 2002, 124, 14696–14706.
[27] M. Ferrer, L. Rodriguez, O. Rossell, F. Pina, J. C. Lima, M. F.
Bardia, X. Solans, J. Organomet. Chem. 2003, 678, 82–89.
[28] G. E. Coates, C. Parkin, J. Chem. Soc. 1962, 3220–3226.
[29] E. C. Constable, C. E. Housecroft, M. Neuburger, S. Schaffner,
E. J. Shardlow, Dalton Trans. 2007, 2631–2633.
[30] A. Pintado-Alba, H. de la Riva, M. Nieuwhuyzen, D. Bautista,
P. R. Raithby, H. A. Sparkes, S. J. Teat, J. M. Lopez-de-Luzuri-
aga, M. C. Lagunas, Dalton Trans. 2004, 3459–3467.
[31] C. M. Che, H. K. Yip, W. C. Lo, S. M. Peng, Polyhedron 1994,
13, 887–890.
[32] A. Pons, O. Rossell, M. Seco, X. Solans, M. FontBardia, J.
Organomet. Chem. 1996, 514, 177–182.
[33] V. W. W. Yam, J. Photochem. Photobiol. A 1997, 106, 75–84.
[34] A. Maspero, I. Kani, A. A. Mohamed, M. A. Omary, R. J. Sta-
ples, J. P. Fackler, Inorg. Chem. 2003, 42, 5311–5319.
[35] X. Hong, K. K. Cheung, C. X. Guo, C. M. Che, J. Chem. Soc.
Dalton Trans. 1994, 1867–1871.
[36] P. G. Jones, C. Thone, Acta Crystallogr. Sect. C 1992, 48, 1312–
1314.
[37] N. C. Payne, R. Ramachandran, R. J. Puddephatt, Can. J.
Chem. 1995, 73, 6–11.
[38] D. S. Eggleston, D. F. Chodosh, G. R. Girard, D. T. Hill, Inorg.
Chim. Acta 1985, 108, 221–226.
S. Friedrichs, P. G. Jones, Acta Crystallogr. Sect. C 2000, 56,
56–57.
V. W. W. Yam, K. K. W. Lo, K. M. C. Wong, J. Organomet.
Chem. 1999, 578, 3–30.
V. W. W. Yam, K. L. Cheung, S. K. Yip, K. K. Cheung, J. Or-
ganomet. Chem. 2003, 681, 196–209.
H. de la Riva, M. Nieuwhuyzen, C. M. Fierro, P. R. Raithby,
L. Male, M. C. Lagunas, Inorg. Chem. 2006, 45, 1418–1420.
R. S. Becker, Theory and Interpretation of Fluorescence and
Phosphorescence, Wiley-Interscience, New York, 1969, p. 234–
238.
V. W. W. Yam, S. W. K. Choi, K. K. Cheung, J. Chem. Soc.
Dalton Trans. 1996, 3411–3415.
[60]
[61]
[62]
V. Pawlowski, H. Kunkely, A. Vogler, Inorg. Chim. Acta 2004,
357, 1309–1312.
M. Bardaji, P. G. Jones, A. Laguna, M. D. Villacampa, N. Vil-
laverde, Dalton Trans. 2003, 4529–4536.
R. Uson, A. Laguna, Organomet. Synth. 1986, 3, 322.
L. Dellaciana, A. Haim, J. Heterocycl. Chem. 1984, 21, 607–
608.
W. Hewertson, H. R. Watson, J. Chem. Soc. 1962, 1490–1494.
G. M. Sheldrick, SHELXL-97: A Program for Automatic Solu-
tion of Crystal Structure, University of Göttingen, Göttingen,
Germany, 1997.
G. M. Sheldrick, SHELXL-97: A Program for Crystal Struc-
ture Refinement, University of Göttingen, Göttingen, Ger-
many, 1997.
[63]
[64]
[65]
[66]
[67]
[68]
[39] A. L. Balch, E. Y. Fung, M. M. Olmstead, J. Am. Chem. Soc.
1990, 112, 5181–5186.
[40] D. Li, X. Hong, C. M. Che, W. C. Lo, S. M. Peng, J. Chem.
Soc. Dalton Trans. 1993, 2929–2932.
[41] M. C. Brandys, R. J. Puddephatt, Chem. Commun. 2001, 1280–
1281.
International Tables of X-ray Crystallography, Kynoch, Bir-
mingham, 1974, vol. IV, pp. 99–100, 149.
Received: February 13, 2008
Published Online: May 8, 2008
Eur. J. Inorg. Chem. 2008, 2899–2909
© 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.eurjic.org
2909