Preparation, structure and decomposition of gold(I) and gold(III) acetylide complexes

Article abstract of DOI:10.1016/j.ica.2004.07.005

1-Alkynyl-dimethyl(triorganophosphine)gold(III) complexes of the type cis-Me₂(Ph₃P)Au-C≡C-R with R = H, Me, Ph (1-3) have been prepared from the cis-Me₂(Ph₃P)AuX (X = Cl, I) complexes and lithium alkynyls. The crystal structures of 1 and 2 have been determined together with those of the reference compounds cis-Me ₂(Ph₃P)AuX (X = Cl, I) and cis-Me₂(Me ₃P)AuI. The molecules have a standard square planar geometry and are not associated into oligomers. Due to the different hybridization of the carbon orbitals, the Au-C(≡CR) bonds are found significantly shorter than the Au-CH₃ bonds. Compounds 1-3 are stable colourless, crystalline solids at 20°C but decompose on heating with selective (cis) reductive elimination of ethane and formation of the gold(I) alkynyls (Ph₃P)Au-C≡C-R thus retaining the stronger gold-alkynyl bonds. Two complexes of this type have also been prepared by conventional routes from (R₃P)AuX complexes and the crystal structures of (Me₃P)Au-C≡C-Ph and [(p-Tol) ₃P]Au-C≡C-H have been determined. The former with the small Me₃P ligand is associated into two different trimers via aurophilic bonding and further aggregated into chains via weak inter-trimer contacts, while the latter is a monomer owing to the steric bulk of the (p-Tol)₃P ligand.

Full text of DOI:10.1016/j.ica.2004.07.005

Inorganica Chimica Acta 358 (2005) 1429–1441
www.elsevier.com/locate/ica
Preparation, structure and decomposition of gold(I) and gold(III)
acetylide complexes
*
Oliver Schuster, Ruei-Yang Liau, Annette Schier, Hubert Schmidbaur
Department Chemie, Technische Universita¨t Mu¨nchen, Lichtenbergstrasse 4, 85747 Garching, Germany
Received 17 June 2004; accepted 5 July 2004
Available online 13 August 2004
Dedicated to Prof. F.G.A. Stone
Abstract
1-Alkynyl-dimethyl(triorganophosphine)gold(III) complexes of the type cis-Me2(Ph3P)Au–C„C–R with R = H, Me, Ph (1–3)
have been prepared from the cis-Me2(Ph3P)AuX (X = Cl, I) complexes and lithium alkynyls. The crystal structures of 1 and 2 have
been determined together with those of the reference compounds cis-Me2(Ph3P)AuX (X = Cl, I) and cis-Me2(Me3P)AuI. The mol-
ecules have a standard square planar geometry and are not associated into oligomers. Due to the different hybridization of the
carbon orbitals, the Au–C(„CR) bonds are found significantly shorter than the Au–CH3 bonds. Compounds 1–3 are stable col-
ourless, crystalline solids at 20 ꢀC but decompose on heating with selective (cis) reductive elimination of ethane and formation of
the gold(I) alkynyls (Ph3P)Au–C„C–R thus retaining the stronger gold-alkynyl bonds. Two complexes of this type have also been
prepared by conventional routes from (R3P)AuX complexes and the crystal structures of (Me3P)Au–C„C–Ph and [(p-Tol)3P]Au–
C„C–H have been determined. The former with the small Me3P ligand is associated into two different trimers via aurophilic
bonding and further aggregated into chains via weak inter-trimer contacts, while the latter is a monomer owing to the steric bulk
of the (p-Tol)3P ligand.
ꢁ 2004 Elsevier B.V. All rights reserved.
Keywords: Gold complexes; Alkynylgold complexes; Organogold complexes; Alkynyl ligands; Acetylide ligands; Reductive elimination
1. Introduction
on aurophilic interactions, with aggregates ranging from
simple dimers to one-dimensional polymers [1]. Like
neutral cyanide or isocyanide molecules R–C„N/R–
N‚C and cyanide anions [C„N]ꢀ, the acetylide anions
[R–C„C]ꢀ are rod-like ligands which give free access to
the metal centres owing to their limited steric require-
ments. Acetylide ligands thus facilitate the close mutual
approach of complex molecules necessary for efficient
aurophilic bonding. However, while metallophilic bond-
ing between gold(I) complexes with rod-like ligands is
thus quite common, and absent only in cases of severe
steric hindrance by the auxiliary ligand L, similar phe-
nomena are virtually unknown in gold(III) coordination
chemistry [6,7].
In recent work, we have revisited the chemistry of
gold(I) acetylide complexes of the types L–Au–C„C–
R and L–Au–C„C–Au–L with L representing a tertiary
phosphine or another neutral donor ligand [1]. Some of
these compounds were prepared already in the early
periods of organogold chemistry, including work in
the laboratories of Coates and Parkin [2,3] and Mitchell
and Stone [4,5]. These compounds have now been
shown to exhibit a rich supramolecular chemistry based
*
Corresponding author. Tel.: +49 89 28913130; fax: +49 89
A survey of the literature on organogold chemistry
has shown that only very few gold(III) acetylide com-
28913125.
E-mail address: H.Schmidbaur@lrz.tum.de (H. Schmidbaur).
0020-1693/$ - see front matter ꢁ 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2004.07.005

1430
O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
plexes are actually known and none of these have been
structurally characterized. In the laboratories of Pudde-
phatt, an early example was prepared and its identity
confirmed beyond doubt by standard analytical and
spectroscopic methods: cis-Me2Au(C„CCF3)(PMePh2)
was obtained from Me3Au(PMePh2) and CF3C„CH
in a sealed tube with elimination of methane [8,9]. Its
C„C bond shows a high stretching frequency at
2148 cmꢀ1, and the methyl groups are NMR non-
equivalent indicative of the cis-orientation. The corre-
sponding phenylacetylide complex cis-Me2Au(C„
CPh)(PPh3) was obtained by Komiya et al. [10] but
no details have been published. It was observed, how-
ever, that this compound readily decomposes affording
Me2(Ph3P)AuCl, the corresponding trimethylgold com-
plex was reacted with HCl (72% yield) [58].
The reactions of the cis-Me2(R3P)AuX complexes
thus obtained with equivalent quantities of a lithium
acetylide in tetrahydrofuran at low temperature gave
good yields of the corresponding cis-dimethyl(alky-
nyl)gold(III) complexes (1–3) as colourless crystalline
products [Eq. (1)]. The compounds are stable in air
at room temperature for short periods of time. The
melting points are all below 100 ꢀC and melting is
accompanied by decomposition with evolution of gas
(v. i.). The compounds are soluble in many of the
common organic solvents, including di- and trichloro-
methane, tetrahydrofuran, dioxane, and toluene. They
have been identified by elemental analysis and IR
and NMR spectroscopy. An IR band to be assigned
to the C„C stretching frequency has only been ob-
served for compound 3 (at 2120 cmꢀ1), while for 1
and 2 the corresponding absorptions are very weak
owing to the low polarity of the triple bonds. The
acetylide „C–H vibration of complex 1 is readily iden-
predominantly
ethane
(C2H6:PhC„CMe = 96:4),
apparently leaving (Ph3P)AuC„CPh as the product
after cis reductive elimination of alkane, but this com-
plex was not isolated.
As compared to the extensive platinum(II) acetylide
chemistry [11–16], the information on the analogous
gold(III) system is very limited [8–10]. It is particularly
noteworthy that the literature is completely devoid of
di-, tri- and tetra-alkynyl-gold(III) complexes. In order
to have a firm basis for a more extensive gold(III) acety-
lide chemistry, we have therefore initiated an investiga-
tion into a few prototype molecules in greater detail,
the results of which are presented in this first account.
A report of the first successful synthesis of poly(acety-
lido)gold(III) complexes is in preparation.
tified at 3276 cmꢀ1
.
R
R
Ph3
P
X
Ph3
P
THF
-78 ˚C
Au
+
LiX
+
Au
Me
Me
Li
Me
Me
(X = Cl, I; R = H, Me, Ph)
ð1Þ
In the NMR spectra, the two methyl groups of each
compound show separate proton and carbon reso-
nances with a diagnostic variation of the coupling con-
stants, which allow assignments to the positions cis and
trans to the phosphorus atom. As for the alkynyl
groups, the terminal hydrogen atom of 1 as well as
the terminal methyl group of 2 give rise to doublet sig-
nals due to coupling with the phosphorus nucleus,
which suggests that neither the methyl groups nor the
alkynyl groups are subject to any rapid substituent ex-
change process. Of the two alkynyl carbon atoms, those
in the b-positions show singlet signals which are readily
identified, but the resonances of those in the a-positions
could not be detected. Similar observations were made
with gold(I) acetylides [1]. The phosphorus resonances
of 1–3 were found in a narrow range (at 26.31, 25.69
and 26.37 ppm), indicating the coordination of Ph3P
to R3Au(III). The shift observed relative to
Ph3PAuMe3 (28.79 ppm) can be attributed to the high-
er s-character and therefore higher electronegativity of
the alkynyl carbon (sp) compared to the methyl carbon
atom (sp3).
Metal acetylide complexes are of general interest
regarding their potential application as luminescent de-
vices for sensors and as non-linear optical materials
[17–57]. The photophysical properties arise from elec-
tronic transitions strongly modified by relativistic effects
and from the high polarizability of the multiple-bond
units. Gold(III) acetylides with a square planar geome-
try can also be employed in crystal engineering with
the metal centres as rectangular connectors and acety-
lide units as rod-like beams.
2. Preparative results
For studies into simple dialkyl(alkynyl)gold(III) com-
plexes, an efficient synthesis of dialkylgold(III) halide
complexes is required. There are several synthetic routes
to cis-Me2(L)AuX compounds [58–66], none of which is
very satisfactory owing to notorious low yields and
occasional irreproducibility. After exploring preparative
alternatives with not much success, we have employed
again the methods published by Fackler and co-workers
[67] for Me3Au(PMe3) and by Tamaki and Kochi [62]
for Me3Au(PPh3). These were converted into the cis-
Me2(L)AuI complexes using equimolar quantities of ele-
mental iodine in dichloromethane with isolated yields
between 60% and 70% [62]. For the preparation of cis-
As a general reactivity test, compound 3 dissolved in
dichloromethane was treated with a drop of aqueous
HCl. The 31P NMR spectrum taken after 1 h at 20 ꢀC
(with occasional shaking) showed that the complex
had been converted quantitatively into cis-dimethyl(tri-

O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
1431
phenylphosphine)gold(III) chloride. The chemical shift
was compared with that of an authentic sample pre-
pared following an established route (v. s.) [58]. This re-
sult indicates that the alkynyl group is the better leaving
group and is most readily displaced by a chloride anion
in a nucleophilic substitution reaction.
In an attempt to afford the trans isomer of complex 3,
a solution of the compound in toluene was heated to 75
ꢀC. The reaction was monitored by 31P{1H} NMR
spectroscopy, but only decomposition affording the
Au(I) complex was observed. The spectra show exclusive
reductive elimination of ethane to leave (triphenylphos-
phine)gold(I) phenylacetylide as the sole product as al-
ready observed by Komiya et al. [10]. This compound
was also identified by comparing its spectral parameters
with those of an authentic sample. The thermal decom-
position of crystals at 90 ꢀC gave similar results. Under
the conditions applied in the experiments, the gold(I)
compound is stable and no elemental gold was
produced.
Reference compounds for alkynylgold(I) species were
prepared from chloro[tri(p-tolyl)phosphine]gold(I) and
acetylene gas in the presence of a base, and from
chloro(trimethylphosphine)gold(I) and lithium phenyl-
acetylide. These syntheses followed established proce-
dures: (Me3P)AuC„CPh is a known compound [3],
while [(p-Tol)3P]AuC„CH was already included in a re-
cent study in this laboratory [1]. Both compounds have
been identified through their analytical and spectro-
scopic data.
Fig. 1. Molecular structure of (Ph3P)AuMe2(CCH) (1) (ORTEP, 50%
probability ellipsoids, methyl and phenyl hydrogen atoms omitted).
˚
Selected bond lengths (A) and angles (ꢀ): Au1–P1 2.3908(9), Au1–C1
2.085(4), Au1–C2 2.083(4), Au1–C11 2.068(4), C11–C12 1.153(6); P1–
Au1–C1 92.97(12), P1–Au1–C2 178.13(13), P1–Au1–C11 93.28(10),
C1–Au1–C2 87.33(17), C1–Au1–C11 172.32(15), C2–Au1–C11
86.57(16), Au1–C11–C12 170.5(3).
3. Structural results
Crystals of cis-dimethyl(ethynyl)(triphenylphos-
phine)gold(III) (1) are monoclinic, space group P21/n
with Z = 4 molecules in the unit cell. The gold atom is
in a square planar configuration with the two methyl
groups in cis positions (Fig. 1). The Au–CH3 distances
˚
[2.083(4), 2.085(4) A] are equal, suggesting that there
is no drastic difference in the trans influence of the phos-
Fig. 2. Stacking of (Ph3P)AuMe2(CCH) molecules (1) viewed along
the b-axis of the unit cell.
phine and the acetylide ligand. However, the Au–CCH
˚
distance [2.068(4) A] is significantly shorter probably
reflecting the transition from sp3 to sp hydridization of
the a-carbon atom. The angles Au1–C11–C12 and
C11–C12–H12 are both smaller than 180ꢀ owing to a
slight bending of the acetylide group away from a phe-
nyl group of the phosphine ligand. There is no evidence
for any specific intermolecular interactions, excluding in
particular aurophilic bonding (shortest Au–Au distance:
bouring stacks have their alkynyl groups aligned in an
antiparallel fashion (neighbouring molecules head-
to-tail) related by a centre of inversion, suggesting the
influence of dipole/induced dipole forces (Fig. 4). The
Au–C–C–CH3 axis is almost perfectly linear: Au1–C3–
C2 178.2(6)ꢀ, C3–C2–C1 179.4(9)ꢀ.
˚
The structures of a few reference compounds have also
5.696 A, Fig. 2).
Crystals of cis-dimethyl(1-propynyl)(triphenylphos-
been determined.
ꢀ
Crystals of cis-chloro-dimethyl(triphenylphosphine)-
gold(III) are monoclinic, space group P21 with Z = 2
molecules in the unit cell. The molecular structure is
shown in Fig. 5. With the trans influence of the tertiary
phine)gold(III) (2) are triclinic, space group P1 with
Z = 2 molecules in the unit cell. The overall structure
and many of its details are very similar to those of com-
pound 1 (Fig. 3). In the unit cell, molecules in neigh-

1432
O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
Fig. 3. Molecular structure of (Ph3P)AuMe2(CCMe) (2) (ORTEP,
50% probability ellipsoids, hydrogen atoms omitted). Selected bond
Fig. 5. Molecular structure of (Ph3P)AuMe2Cl (ORTEP, 50% prob-
˚
ability ellipsoids, hydrogen atoms omitted). Selected bond lengths (A)
˚
lengths (A) and angles (ꢀ): Au1–P1 2.3870(13), Au1–C5 2.096(6), Au1–
C4 2.086(6), Au1–C3 2.095(6), C3–C2 1.136(9), C2–C1 1.485(10); P1–
Au1–C5 92.13(18), P1–Au1–C4 175.66(17), P1–Au1–C3 94.71(16), C5–
Au1–C4 86.1(3), C5–Au1–C3 173.0(2), C4–Au1–C3 87.0(3), Au1–C3–
C2 178.2(6), C3–C2–C1 179.4(9).
and angles (ꢀ): Au1–P1 2.3886(9), Au1–C12 2.068(3), Au1–C11
2.077(3), Au1–Cl1 2.3864(9); P1–Au1–C12 89.69(10), P1–Au1–C11
176.36(17), P1–Au1–Cl1 94.27(3), C12–Au1–C11 87.17(15), C12–Au1–
Cl1 175.66(10), C11–Au1–Cl1 88.93(11).
dihedral angle Cl1–Au1–P1–C131 23.9(9)ꢀ], and one of
the methyl groups (C12) in a staggered position between
two phenyl groups (C111, C121). This preference indi-
cates that the steric bulk of a methyl group should be ta-
ken as slightly larger than that of a chloride substituent,
but with the dihedral angle deviating very significantly
from 0ꢀ the difference cannot be great. The packing of
the molecules in the unit cell shows an alignment of
Au–Cl vectors in one direction, but without a parallel
orientation of the individual functions (Fig. 6).
Crystals of cis-dimethyl(iodo)(triphenylphosphine)-
gold(III) are orthorhombic, space group P212121 with
Z = 4 molecules in the unit cell. The structure of the
molecule as presented in Fig. 7 shows the same general
features as the chloride analogue (above). The Au–C
bonds lengths are the same within the experimental lim-
its owing to the less electronegative, soft character of
iodide as compared to chloride. The conformation of
the molecule regarding the rotation of the phosphine lig-
and about the Au–P bond places the iodine atom be-
tween two phenyl rings (C11, C21) corresponding to a
staggered conformation, with a dihedral angle C1–
Au1–P1–C31 17.4(3) showing the concomitant eclipsed
orientation of the third phenyl group (C31) and one of
the methyl groups (C1). The packing of the molecule
is shown in Fig. 8.
Fig. 4. Stacking of (Ph3P)AuMe2(CCMe) molecules (2) viewed along
the a-axis of the unit cell. The alkynyl groups of adjacent stacks show
antiparallel orientation.
phosphine ligand and the chloride anion different, there
is a variation in the Au–CH3 distances [2.068(3) and
˚
2.077(3) A]. The conformation of the molecule regard-
ing the rotation of the phosphine ligand about the
Au–P bond places the chlorine atoms in a somewhat
eclipsed position with one of the phenyl rings [C131,
Crystals of cis-dimethyl(iodo)(trimethylphosphine)-
gold(III) are monoclinic, space group P21 with Z = 2
molecules in the unit cell. The molecular structure is
shown in Fig. 9. It is largely analogous to that of the tri-

O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
1433
Fig. 8. Stacking of (Ph3P)AuMe2I molecules viewed along the a-axis
of the unit cell.
Fig. 6. Stacking of (Ph3P)AuMe2Cl molecules viewed along the a-axis
of the unit cell.
Fig. 9. Molecular structure of (Me3P)AuMe2I (ORTEP, 50% proba-
˚
bility ellipsoids, hydrogen atoms omitted). Selected bond lengths (A)
and angles (ꢀ): Au1–P1 2.354(2), Au1–C2 2.066(10), Au1–C1 2.074(7),
Au1–I1 2.7014(6); P1–Au1–C2 92.6(3), P1–Au1–C1 178.9(3), P1–Au1–
I1 90.38(5), C2–Au1–C1 86.6(4), C2–Au1–I1 177.1(3), C1–Au1–I1
90.5(3).
Fig. 7. Molecular structure of (Ph3P)AuMe2I (ORTEP, 50% proba-
˚
bility ellipsoids, hydrogen atoms omitted). Selected bond lengths (A)
and angles (ꢀ): Au1–P1 2.3896(17), Au1–C1 2.116(7), Au1–C2
2.099(7), Au1–I1 2.6886(6); P1–Au1–C1 91.6(2), P1–Au1–C2
177.2(2), P1–Au1–I1 92.35(4), C1–Au1–C2 86.6(3), C1–Au1–I1
175.47(18), C2–Au1–I1 89.5(2).
Crystals of ethynyl[tri(p-tolyl)phosphine]gold(I) are
monoclinic, space group P21/c with Z = 8 molecules in
the unit cell. The asymmetric unit contains two inde-
pendent molecules with very similar structural details
(Fig. 11(a) and (b)). Both alkynyl hydrogen atoms have
been located and their positions refined with isotropic
parameters. The Au–C distances in these gold(I) com-
phenylphosphine complex. With a dihedral angle C2–
Au2–P1–C11 of only ꢀ1.0(6)ꢀ, the conformation of
the molecule is again fully staggered, suggesting an over-
ruling effect of the bulky iodine atom. In the unit cell,
molecules of neighbouring stacks have their C–Au–I
and I–Au–C axes mutually antiparallel as observed for
the alkynyl complexes (above), but at long distances
which rule out any short-range interactions (Fig. 10).
˚
plexes are found exactly equal [2.006(6) A] and very sig-
nificantly shorter than those found for the above
˚
ethynylgold(III) compound [2.068(4) A]. This distance

1434
O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
(a)
Fig. 10. Stacking of the (Me3P)AuMe2I molecules viewed along the
a-axis of the unit cell.
probably reflects the much higher s-character of the
bonding orbitals of gold(I) as compared to gold(III),
and the different trans influence of a tertiary phosphine
in the first case and of an alkyl group in the second.
The axes P–Au–C„C–H are linear with individual an-
gles differing only a few degrees from the expected
180ꢀ. In the unit cell, the molecules are not aggregated
into oligomers, probably owing to the steric bulk of
the tertiary phosphine. The complex Me2PhPAuC„CH
with a smaller ligand is associated into a dimer via a
short aurophilic contact [1].
Crystals of phenylethynyl(trimethylphosphine)gold(I)
obtained from dichloromethane are triclinic, space
(b)
ꢀ
group P1 with Z = 12 complex molecules and four sol-
vent molecules in the unit cell. The asymmetric unit con-
tains no less than six independent monomers with
similar geometries and two CH2Cl2 molecules (Fig.
12). The average of the six Au–C bond lengths (2.073
Fig. 11. Molecular structures of the two independent [(p-Tol)3-
P]Au(CCH) molecules (ORTEP, 50% probability ellipsoids, hydrogen
˚
atoms omitted). Selected bond lengths (A) and angles (ꢀ): (a) Au1–P1
2.2804(14), Au1–C1 2.006(6), C1–C2 1.172(9); P1–Au1–C1 176.91(17),
Au1–C1–C2 175.9(6). (b) Au2–P2 2.2856(14), Au2–C3 2.006(6), C3–
C4 1.171(9); P2–Au2–C3 175.81(18), Au2–C3–C4 176.3(6).
˚
A) for this alkynylgold(I) species is again significantly
shorter than the distances found for the two alkynyl-
gold(III) compounds, and similar arguments can be used
to explain this variation, but in addition there is now the
electronic influence of the phenyl group. The monomers
are organized in two different strings (Fig. 13). In each
of the two strings, trimers are discernible in which the
˚
Au2–Au3 3.3678(6) A. The Au–Au–Au angles are found
to be 148.34(2)ꢀ and 142.71(2)ꢀ, respectively. In each tri-
mer, the molecular axes of the monomeric units are not
parallel or anti-parallel, but rotated against each other
with dihedral angles P1–Au1–Au2–P2 119.2(1)ꢀ, P2–
Au2–Au3–P3 116.6(1)ꢀ, P4–Au4–Au5–P5 11.6(1)ꢀ, and
P5–Au5–Au6–P6 112.1(1)ꢀ. These onsets of helical
structures are continued when moving to the neighbour-
˚
Au–Au contacts are shorter than 3.4 A. The first trimer
is most tightly bonded with contacts Au4–Au5 of
˚
3.1140(6) and Au5–Au6 of 3.0233(6) A, while the second
one has longer distances with Au1–Au2 3.2812(6) and

O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
1435
corresponding halides cis-R2(L)AuX with alkali acety-
lides in a polar solvent at room temperature. The prod-
ucts are colourless crystalline solids which are stable at
room temperature. At elevated temperatures (typically
50–100 ꢀC), the compounds undergo clean, selective
(cis) reductive elimination of alkane R2 to leave the cor-
responding gold(I) complexes (L)AuC„CR0. This mode
of decomposition suggests that the Au–C(„CR) bonds
are more robust than the Au–R bonds, but a kinetic ef-
fect cannot be ruled out.
In two crystal structure investigations (1 and 2), the
square-planar cis-structure of the complexes, suggested
by the scheme of the syntheses, by the diamagnetism
and by the NMR data, has been confirmed. The Au–
C(„CR) bonds were found to be significantly shorter
than the Au–CH3 bonds as expected for a higher s-char-
acter of the carbon orbitals involved in Au–C bonding
in the former (sp versus sp3). With the two Au–CH3
bonds having the same distance in both cases, it appears
that the trans influence of the phosphine and the alkynyl
ligands is not that grossly different that this would be
discernible in bond length parameters.
Fig. 12. Representative monomeric unit in the crystal structure of
(Me)3PAu(CCPh) Æ 1/3CH2Cl2 (ORTEP, 50% probability ellipsoids,
hydrogen atoms omitted). Selected bond lengths (A) and angles (ꢀ):
Au5–P5 2.279(3), Au5–C51 2.034(11), C51–C52 1.172(14), C52–C53
1.457(15); P5–Au5–C51 176.9(3), Au5–C51–C52 175.4(10), C51–C52–
C53 176.6(12).
˚
In two crystal structural studies of complexes
(L)AuC„CR, the Au–C(„CR) bonds were found even
shorter, probably owing to the higher s-character of the
orbitals of two-coordinate gold(I) in Au–C bonding, as
compared to those of square-planar gold(III) (sp versus
dsp2).
In the crystal, (Me3P)AuC„CPh with its small terti-
ary phosphine ligand is associated into two different
types of trimers through aurophilic bonding. One kind
of these trimers [which has the longer Au–Au contacts
˚
of 3.2812(6) and 3.3678(6) A] is further aggregated into
helical chains establishing larger inter-trimer Au–Au
˚
distances of almost 3.5 A. The other kind of trimers
[with the shorter Au–Au contacts of 3.1140(6) and
˚
3.0233(6) A] is also lined up in chains, but the external
Fig. 13. Two independent chains of (Me)3PAu(CCPh) units
[Au1ꢁ ꢁ ꢁAu2 3.2812(6), Au2ꢁ ꢁ ꢁAu3 3.3678(6), Au3ꢁ ꢁ ꢁAu100 3.4839(6),
Au4ꢁ ꢁ ꢁAu5 3.1140(6), Au5ꢁ ꢁ ꢁAu6 3.0233(6), Au6ꢁ ꢁ ꢁAu400 4.2885(6) A;
˚
Au30ꢁ ꢁ ꢁAu1ꢁ ꢁ ꢁAu2 150.596(16), Au1ꢁ ꢁ ꢁAu2ꢁ ꢁ ꢁAu3 148.341(17),
Au2ꢁ ꢁ ꢁAu3ꢁ ꢁ ꢁAu100 136.966(17), Au60ꢁ ꢁ ꢁAu4ꢁ ꢁ ꢁAu5 137.885(16),
Au4ꢁ ꢁ ꢁAu5ꢁ ꢁ ꢁAu6 142.714(17), Au5ꢁ ꢁ ꢁAu6ꢁ ꢁ ꢁAu400 127.623(15)ꢀ; P1–
Au1ꢁ ꢁ ꢁAu2–P2 119.18(12), P2–Au2ꢁ ꢁ ꢁAu3–P3 116.60(12), P4-
Au4ꢁ ꢁ ꢁAu5–P5 111.56(12), P5–Au5ꢁ ꢁ ꢁAu6–P6 112.12(12)ꢀ ].
Au–Au contacts are so long that they qualify only as
weak van der Waals type. This supramolecular structure
shows that with small ligands L (e.g.: PMe3) and slim
acetylide groups, aggregation of a gold(I) complex via
aurophilic bonding is absolutely predictable. Like many
complexes with aurophilicity effects discernible in the
crystal, (Me3P)AuC„CPh exhibits luminescence. A cor-
relation between these two effects is generally accepted
[49–57]. Experimental and theoretical studies on lumi-
nescent Pt(II) complexes have supported the assumption
of a strong relationship between optoelectronic proper-
ties and metal–metal interactions [68,69].
ing trimers, which are close by for the loosely bound
Au1–Au2–Au3 unit with an Au1ꢁ ꢁ ꢁAu300 distance of
˚
3.4839(6) A, but further away for the tightly bonded
Au4–Au5–Au6 unit with an Au4–Au60 distance as long
˚
as 4.2885(6) A. The latter can only be considered a very
weak van der Waals contact.
By contrast, the molecules [(p-Tol)3P]AuC„CH with
a larger phosphine L and the smallest possible acetylide
group are not associated in the crystal and in the unit
cell no alignment whatsoever is discernible, and no lumi-
nescence is observed.
4. Discussion
The present study has shown that gold(III) acetylide
complexes of the type cis-R2Au(L)C„CR0 are readily
available via nucleophilic substitution reactions of the
It is very tempting to ascribe this absence of aurophi-
lic bonding in a gold(I) complex solely to the steric bulk

1436
O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
of its (p-Tol)3P ligand. However, recent work by Bott
et al. [70] has shown that [(p-Tol)3P]AuBr can exist in
two different modifications, one of which has the mole-
cules as rather tightly bonded dimers, while in the other
no aggregation is observed. The authors have pointed
out that there is a delicate balance between a series of ef-
fects which all contribute to the overall stability of a
molecular crystal. With a large number of aryl groups
in the ligands, a set of p-stacking and weak hydrogen-
bonding effects may well overrule aurophilic bonding
even though the ligand bulk is not fully prohibitive.
The gold(III) acetylide compounds 1 and 2 are not
aggregated in the crystal. Inspection of the structural
models shows that the broad-side approach necessary
for contacts between the metal atoms is severely hin-
dered by the ligands even if staggered conformations
are chosen for metal-to-metal stacking. With ‘‘slipped’’
stacking, the Auꢁ ꢁ ꢁAu contacts are lost altogether.
Therefore, with tertiary phosphines as ligands no effi-
cient aurophilic bonding is to be expected. In further
studies, isocyanide ligands should be employed instead,
which are rod-like similar to the acetylide groups.
cuo and the residue recrystallized from dichlorometh-
ane/n-pentane at ꢀ30 ꢀC. 78 mg (61% yield) of
colourless crystals; m.p. (dec.): 60–63 ꢀC. 1H NMR
3
(CD2Cl2, RT): d = 1.18 [d, JHP = 9.5 Hz, 3H, trans-P–
3
Au–CH3], 1.35 [d, JHP = 8.8 Hz, 3H, cis-P–Au–CH3],
2
1.66 [d, JHP = 10.2 Hz, 9H, P(CH3)]. 13C{1H} NMR
2
(CD2Cl2, RT): d = 11.9 [d, JCP = 123.0 Hz, trans-P–
1
Au–CH3], 13.7 [d, JCP = 30.8 Hz, P(CH3)], 20.0 [d,
2JCP = 42.3 Hz, cis-P–Au–CH3]. 31P{1H} NMR
(CD2Cl2, RT): d = ꢀ7.32 [s]. Anal. Calc. for C5H15AuIP
(430.01 g molꢀ1): C, 13.97; H, 3.52. Found: C, 13.46; H,
3.45%.
5.1.2. cis-Dimethyl(iodo)(triphenylphosphine)gold(III),
cis-(Ph3P)AuMe2I [62]
The synthesis was carried out with 151 mg (0.3 mmol)
of (Ph3P)AuMe3 and 76 mg (0.3 mmol) of I2 using the
same procedure as described above. 129 mg (70% yield)
of colourless crystals were collected after recrystalliza-
1
tion; m.p. (dec.): 109–111 ꢀC. H NMR (CD2Cl2, RT):
3
d = 1.14 [d, JHP = 8.1 Hz, 3H, trans-P–Au–CH3], 1.52
[d, JHP = 9.0 Hz, 3H, cis-P–Au–CH3], 7.35–7.71 [m,
3
15H, P(C6H5)]. 13C{1H} NMR (CD2Cl2, RT): d = 14.6
[d, JCP = 115.7 Hz, trans-P–Au–C H3], 20.7 [d,
2
2
5. Experimental
2JCP = 4.2 Hz, cis-P–Au–CH3], 129.0 [d, JCP = 10.4
4
Hz, o-P(C6H5)], 131.7 [d, JCP = 1.6 Hz, p-P(C6H5)],
1
5.1. General procedure
134.6 [d, JCP = 11.9 Hz, i-P(C6H5)], 135.1 [d,
3JCP = 10.9 Hz, m-P(C6H5)]. 31P{1H} NMR (CD2Cl2,
RT): d = 29.14 [s]. Anal. Calc. for C20H21AuIP (616.20
g molꢀ1): C, 38.98; H, 3.43. Found: C, 40.24; H, 3.37%.
All organometallic syntheses were performed in a dry
deoxygenated dinitrogen atmosphere using standard
Schlenk techniques. All solvents were distilled from an
appropriate drying agent and stored over molecular sieves
5.1.3. cis-(Chloro)dimethyl(triphenylphosphine)gold(III),
cis-(Ph3P)AuMe2Cl [58]
˚
(4 A) and under nitrogen. Solutions were handled at
ꢀ78 ꢀC unless otherwise stated and protected against
light. All standard chemicals and lithium acetylides were
purchased from Aldrich or Fluka and used without fur-
ther purification. (Ph3P)AuMe3 [62], (Me3P)AuMe3 [67],
(tht)AuCl [71], (Me3P)AuCl [72], (Ph3P)AuCl [73], and
(p-Tol)3PAuCl [73] were prepared by the literature meth-
ods. NMR spectra were obtained on JEOL-400 or JEOL-
270 spectrometers. Chemical shifts are reported in d
values relative to the residual solvent resonances con-
verted to TMS (1H). 31P{1H} NMR spectra are referenced
to external aqueous H3PO4 (85%). The single crystal X-
ray diffraction measurements were performed at ꢀ130 ꢀC
on a Nonius DIP 2020 diffractometer using graphite mon-
ochromated Mo Ka radiation. IR spectra were measured
on a Perkin–Elmer FT-IR 577 spectrometer.
A sample of Ph3PAuMe3 (200 mg, 0.4 mmol) was dis-
solved in 4 ml of toluene and treated with 0.456 ml (5.5
mmol) of conc. aqueous hydrochloric acid. When no fur-
ther evolution of gas was observed (ca. 1 h), the clear
solution was evaporated in vacuo to give a white solid,
which was recrystallized from toluene/n-pentane to af-
ford 150 mg (72% yield) of a microcrystalline white pow-
1
der; m.p. (dec.): 122–124 ꢀC. H NMR (CD2Cl2, RT):
3
d = 0.92 [d, JHP = 8.66 Hz, 3H, cis-P–Au–CH3], 1.36
[d, JHP = 9.4 Hz, 3H, trans-P–Au–CH3], 7.34–7.79 [m,
3
15H, P(C6H5)]. 13C{1H} NMR (CD2Cl2, RT): d = 10.8
[d, JCP = 4.7 Hz, cis-P–Au–CH3], 19.7 [d, JCP = 114.7
2
2
1
Hz, trans-P–Au–CH3], 128.3 [d, JCP = 45.2 Hz, i-
3
P(C6H5)], 129.0 [d, JCP = 10.4 Hz, m-P(C6H5)], 131.6
4
2
[d, JCP = 2.1 Hz, p-P(C6H5)], 134.8 [d, JCP = 10.9 Hz,
o-P(C6H5)]. 31P{1H} NMR (CD2Cl2, RT): d = 33.05
[s]. Anal. Calc. for C20H21AuClP (524.75 g molꢀ1): C,
45.77; H, 4.03. Found: C, 45.83; H, 3.88%.
5.1.1. cis-Dimethyl(iodo)(trimethylphosphine)gold(III),
cis-(Me3P)AuMe2I [62]
95 mg (0.3 mmol) of (Me3P)AuMe3, dissolved in a
minimum volume of dichloromethane, was treated with
one equivalent (76 mg, 0.3 mmol) of iodine dissolved in
the same solvent. Evolution of gas was observed. After 2
h of continuous stirring, the solvent was removed in va-
5.1.4. cis-Dimethyl(2-phenylethynyl)(triphenylphosphine)-
gold(III), cis-(Ph3P)AuMe2(CCPh) (3)
To a Schlenk flask containing 105 mg (0.2 mmol) of
cis-(Ph3P)AuMe2Cl in 25 ml of THF kept at ꢀ78 ꢀC

O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
1437
was added dropwise 0.2 ml (0.2 mmol, 1.0 M) of PhC2Li
in THF. With continued stirring, the resultant solution
was slowly allowed to warm up to room temperature.
LiCl was formed as a white precipitate. After evapora-
tion of the solvent under reduced pressure, the residue
was extracted twice with 50 ml of n-pentane. The solvent
of the combined extracts was removed in vacuo and the
residue recrystallized from dichloromethane/n-pentane
at ꢀ30 ꢀC to yield 79 mg (67% yield) of colourless crys-
tals; m.p. (dec.): 83–85 ꢀC. 1H NMR (CD2Cl2, RT):
the lithium acetylide ethylenediamine complex. After
recrystallization from dichloromethane/n-pentane, 55
mg (71% yield) of colourless crystals was collected; m.p.
1
(dec.): 92–93 ꢀC. H NMR (CD2Cl2, RT): d = 0.23 [d,
3
3JHP = 8.4 Hz, 3H, cis-P–Au–CH3], 1.31 [d, JHP = 9.2
4
Hz, 3H, trans-P–Au–CH3], 2.08 [d, JHP = 2.9 Hz, 1H,
Au–C„CH], 7.29–7.69 [m, 15H, P(C6H5)]. 13C{1H}
2
NMR (CD2Cl2, RT): d = 7.2 [d, JCP = 5.4 Hz, cis-P–
Au–CH3], 12.5 [d, JCP = 114.5 Hz, trans-P–Au–CH3],
2
3
94.5 [s, Au–C„CH], 129.0 [d, JCP = 10.8 Hz, m-
P(C6H5)], 131.6 [d, JCP = 2.3 Hz, p-P(C6H5)], 134.1 [d,
3
4
d = 0.33 [d, JHP = 8.2 Hz, 3H, cis-P–Au–CH3], 1.39
3
[d, JHP = 9.2 Hz, 3H, trans-P–Au–CH3] 6.95–7.77 [m,
2
1JCP = 19.2 Hz, i-P(C6H5)], 135.0 [d, JCP = 10.8 Hz, o-
20H, C6H5]. 13C{1H} NMR (CD2Cl2, RT): d = 7.1 [d,
P(C6H5)], Au–C„CH was not observed.
P{1H}
31
2
2JCP = 4.7 Hz, cis-P–Au–CH3], 11.7 [d, JCP = 114.7
NMR (CD2Cl2, RT) d = 26.31 [s]. IR (KBr) [cmꢀ1]: 692
(s), 751 (s), d (Ar, monosubst.); 1434 (s), 1479 (m), 1560
(m), m(C‚C, aromat.); 2913 (m), m(C–H); 3048 (m),
m(Ar–H); 3276 (m), m(C„CH); m(C„C) was not ob-
served. Anal. Calc. for C22H22AuP (514.33 g molꢀ1): C,
51.37; H, 4.31. Found: C, 51.82; H, 4.39%.
Hz, trans-P–Au–CH3], 108.5 [s, Au–C„C–C6H5],
121.5 [d, JCP = 15.6 Hz, i-C2(C6H5)], 126.2 [s, o-
3
C2(C6H5)], 128.2.6 [s, p-C2(C6H5)], 129.0 [d,
3JCP = 10.4 Hz, m-P(C6H5)], 129.5 [s, p-P(C6H5)], 131.4
1
[d, JCP = 14.0 Hz, i-P(C6H5)], 131.5 [s, m-C2(C6H5)],
2
134.9 [d, JCP = 10.9 Hz, o-P(C6H5)], Au–CC–C6H5
was not observed. 31P{1H} NMR (CD2Cl2, RT): 26.27
[s]. IR (KBr) [cmꢀ1]: 691 (s), 746 (s), d (Ar, monosubst.);
1434 (s), 1483 (s), 1594 (m), m(C‚C, aromat.); 2120 (m)
m(C„C); 2910 (m), 2956 (m), m(CH); 3053 (m), m(Ar–H).
Anal. Calc. for C28H26AuP (590.45 g molꢀ1): C, 56.96;
H, 4.44. Found: C, 57.71; H, 4.77%.
5.1.7. Reaction of cis-dimethyl(2-phenylethynyl)(triphe-
nylphosphine)gold(III) with HCl
To a NMR tube containing a sample of 3 dissolved in
CD2Cl2, one drop of concentrated aqueous HCl was
added. After 1 h with occasional shaking, a 31P{1H}
NMR spectrum was recorded.
5.1.5. cis-Dimethyl(2-methylethynyl)(triphenylphosphine)-
gold(III), cis-(Ph3P)AuMe2(CCMe) (2)
5.1.8. cis–trans Isomeration and thermal decomposition of
cis-dimethyl(2-phenylethynyl)(triphenylphosphine)gold-
(III) in toluene
A sample of 3 dissolved in toluene was warmed to 75
ꢀC and the solution stirred for 24 h at this temperature.
The reaction was monitored by 31P{1H} NMR
spectroscopy.
The compound was synthesized in the same manner
as described for 3 from 262 mg (0.5 mmol) of cis-
(Ph3P)AuMe2Cl and 1 ml (0.5 mmol, 0.5 M) of MeC2Li
in THF. Recrystallization of the raw product from
dichloromethane/n-pentane gave 198 mg (75% yield) of
colourless crystals; m.p. (dec.): 87–88 ꢀC. 1H NMR
3
(CD2Cl2, RT): d = 0.21 [d, JHP = 8.2 Hz, 3H, cis-P–
5.1.9. Thermal decomposition of solid cis-dimethyl(2-
phenylethynyl)(triphenylphosphine)gold(III)
Some crystals of 3 were heated cautiously in inert oil
to 90 ꢀC ensuring that no elemental gold was deposited.
When gas evolution subsided, a 31P{1H} NMR spec-
trum was recorded.
3
Au–CH3], 1.27 [d, JHP = 9.4 Hz, 3H, trans-P–Au–
5
CH3], 1.60 [d, JHP = 2.5 Hz, 3H, Au–C„C–CH3],
7.34–7.75 [m, 15H, P(C6H5)]. 13C{1H} NMR (CD2Cl2,
2
RT): d = 5.5 [s, Au–C„C-CH3], 6.7 [d, JCP = 5.7 Hz,
cis-P–Au–CH3], 11.4 [d, JCP = 117.8 Hz, trans-P–Au–
2
3
C H3], 102.6 [s, Au–C„C–CH3], 128.9 [d, JCP = 10.4
Hz, m-P(C6H5)], 131.4 [s, p-P(C6H5)], 131.8 [d,
5.1.10. Ethynyl [tri(p-tolyl)phosphine] gold(I), (p-Tol)3-
PAu(CCH) [1]
2
1JCP = 14.5 Hz, i-P(C6H5)], 134.9 [d, JCP = 10.4 Hz, o-
P(C6H5)], Au–C„C–CH3 was not observed. 31P{1H}
NMR (CD2Cl2, RT): d = 25.69 [s]. IR (KBr) [cmꢀ1]:
684 (s), 746 (s), d(Ar, monosubst.); 1423 (s), 1476 (s),
1576 (m), m(C‚C, aromat.); 2910 (m), 2947 (m), m(C–
H); 3046 (m), (Ar–H); m(C„C) was not observed. Anal.
Calc. for C23H24AuP (528.36 g molꢀ1): C, 52.82; H,
4.58. Found: C, 50.45; H, 4.23%.
The compound was prepared by an established proce-
dure [1]. A suspension of (p-Tol)3PAuCl (2.0 g, 3.7
mmol) in ethanol (100 ml) was saturated with acetylene
gas at ꢀ60 ꢀC for 1 h. Subsequently, a solution of freshly
prepared sodium ethanolate [0.09 g of sodium metal (3.9
mmol) dissolved in 10 ml of ethanol] was slowly added
with stirring. Acetylene gas was bubbled through the
reaction mixture for another 3 h. On warming a white
precipitate formed, which was collected and washed
with water. Recrystallization from dichloromethane/n-
pentane yielded 1.34 g (71% yield) of colourless crystals;
m.p. (dec.): 145 ꢀC. 1H NMR (CD2Cl2, RT): d = 1.62 [s,
5.1.6. cis-Dimethyl(ethynyl)(triphenylphosphine)gold(III),
cis-(Ph3P)AuMe2(CCH) (1)
In an analogous procedure, 79 mg (0.15 mmol) of cis-
(Ph3P)AuMe2Cl was treated with 14 mg (0.15 mmol) of

1438
O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
Table 1
Crystal data, data collection and structure refinement details for cis-(Ph3P)AuMe2(CCH) (1) and cis-(Ph3P)AuMe2(CCMe) (2)
cis-(Ph3P)AuMe2(CCH) (1) cis-(Ph3P)AuMe2(CCMe) (2)
22H22AuP
Empirical formula
Molecular weight
Crystal system
Space group
C
C23H24AuP
528.36
triclinic
514.33
monoclinic
P21/n
ꢀ
P1
˚
a (A)
13.9302(2)
10.0071(2)
13.9590(2)
90
9.3838(1)
9.9544(2)
12.8344(2)
70.058(1)
71.452(1)
64.919(1)
999.29(4)
1.756
˚
b (A)
˚
c (A)
a (ꢀ)
b (ꢀ)
c (ꢀ)
101.912(1)
90
3
˚
V (A )
1903.99(5)
1.794
qcalc (g cmꢀ3
Z
)
4
992
2
512
F(000)
l (Mo Ka) (cmꢀ1
T (K)
)
78.10
143
45072
74.43
143
23213
Number of measured reflections
Number of unique reflections (Rint
Refined parameters/restraints
R1 [I P 2r(I)]
)
3809 (0.046)
224/0
0.0226
3445 (0.047)
224/0
0.0298
a
wR2
0.0494
0.0773
a = 0.0451; b = 4.8292
2.539/ꢀ1.504
Weighting scheme ꢀ3
˚
fin(max/min) (e A )
a = 0.0000; b = 3.5712
1.176/ꢀ0.579
2
r
P
P
2
2
1=2
a
wR2 ¼ f ½wðF 2o ꢀ F 2cÞ ꢂ= ½wðF o2Þ ꢂg ; w ¼ 1=½r2ðF o2Þ þ ðapÞ þ bpꢂ; p ¼ ðF o2 þ 2F 2c Þ=3.
Table 2
Crystal data, data collection and structure refinement details for cis-(Ph3P)AuMe2Cl, cis-(Ph3P)AuMe2I and cis-(Me3P)AuMe2I
cis-(Ph3P)AuMe2Cl
20H21AuClP
524.75
cis-(Ph3P)AuMe2I
cis-(Me3P)AuMe2I
Empirical formula
Molecular weight
Crystal system
Space group
C
C20H21AuIP
616.20
C5H15AuIP
430.01
monoclinic
P21
orthorhombic
P212121
9.6037(2)
10.8980(2)
18.4920(5)
90
monoclinic
P21
˚
a (A)
7.9946(1)
14.0571(2)
8.9944(1)
90
7.9789(2)
8.9349(5)
8.2891(2)
90
˚
b (A)
˚
c (A)
a (ꢀ)
b (ꢀ)
c (ꢀ)
111.919(1)
90
90
90
118.7753(9)
90
3
˚
V (A )
937.37(2)
1.859
1935.39(7)
2.115
517.96(2)
2.757
qcalc (g cmꢀ3
Z
)
2
504
4
1152
2
384
F(000)
l (Mo Ka) (cmꢀ1
T (K)
)
80.72
143
22202
92.76
143
49904
172.63
143
11647
Number of measured reflections
Number of unique reflections (Rint
Refined parameters/restraints
R1 [I P 2r(I)]
)
3777 (0.054)
208/1
0.0163
3477 (0.072)
210/0
0.0254
1858 (0.078)
78/1
0.0251
a
wR2
0.0461
0.0554
0.0664
Absolute structure factor
Weighting scheme ꢀ3
0.011(5)
a = 0.0000; b = 0.0000
0.997/ꢀ0.454
2
0.020(7)
a = 0.0109; b = 9.1049
0.721/ꢀ1.100
0.025(8)
a = 0.028; b = 0.837
2.549/ꢀ0.974
˚
fin(max/min) (e A
r
)
P
P
2
2
1=2
a
wR2 ¼ f ½wðF 2o ꢀ F 2cÞ ꢂ= ½wðF o2Þ ꢂg ; w ¼ 1=½r2ðF o2Þ þ ðapÞ þ bpꢂ; p ¼ ðF o2 þ 2F 2c Þ=3.
1
1H, Au–C„CH], 2.36 [s, 9H, P–Ar–CH3], 7.25 [dd,
2JCP = 139 Hz, Au–C„CH], 125.4 [d, JCP = 58.6 Hz,
i-P(C6H4)], 129.2 [d, JCP = 12.0 Hz, m-P(C6H4)], 131.5
4
3
3JHH = 8.1 Hz, JP = 1.8 Hz, 2H, m-P(C6H4)], 7.42 [dd,
3
4
2
3JHH = 8.1 Hz, JHP = 13.3 Hz, 2H, o-P(C6H4)].
[d, JCP = 13.7 Hz, p-P(C6H4)], 135.8 [d, JCP = 2.4 Hz,
o-P(C6H4)]. 31P{1H} NMR (CD2Cl2, RT): d = 40.45
[s]. IR (Nujol) [cmꢀ1]: 3276 (vw), m(C„C–H). Raman
13C{1H} NMR (CD2Cl2, RT): d = 21.5 [s, P-Ar-CH3],
3
94.5 [d, JCP = 26.5 Hz, Au–C„C H], 127.0 [d,

O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
1439
Table 3
Crystal data, data collection and structure refinement details for [(p-Tol)3P]Au(CCH) and (Me3P)Au(CCPh) Æ CH2Cl2
[(p-Tol)3P]Au(CCH)
(Me3P)Au(CCPh) Æ CH2Cl2
Empirical formula
Molecular weight
Crystal system
Space group
C23H22AuP
52.34
C11.3H14.6AuCl0.6
402.47
triclinic
P
monoclinic
P21/c
ꢀ
P1
˚
a (A)
9.4175(2)
21.9742(4)
19.7824(5)
90
9.4286(2)
15.1847(4)
28.1175(9)
81.445(1)
85.0185(9)
80.884(3)
3922.26(18)
2.045
˚
b (A)
˚
c (A)
a (ꢀ)
b (ꢀ)
c (ꢀ)
97.321(2)
90
3
˚
V (A )
4060.52(15)
1.722
qcalc (g cmꢀ3
Z
)
8
2032
12
2256
F(000)
l (Mo Ka) (cmꢀ1
T (K)
)
73.27
143
114.73
143
105871
Number of measured reflections
Number of unique reflections (Rint
Refined parameters/restraints
R1 [I P 2r(I)]
131.597
7990 (0.064)
459/0
)
12161 (0.054)
758/0
0.0444
0.0356
0.0857
a
wR2
Weighting scheme ꢀ3
0.1024
a = 0.0386; b = 37.0184
1.740/ꢀ1.188
a = 0.0408; b = 10.3803
1.115/ꢀ1.028
2
˚
fin(max/min) (e A
r
)
P
P
2
2
1=2
a
wR2 ¼ f ½wðF 2o ꢀ F 2c Þ ꢂ= ½wðF o2Þ ꢂg ; w ¼ 1=½r2ðF o2Þ þ ðapÞ þ bpꢂ; p ¼ ðF o2 þ 2F 2c Þ=3.
(powder) [cmꢀ1]: 1981.8 (s), m(C„C). Anal. Calc. for
C23H22AuP (526.37 g molꢀ1): C, 52.48; H, 4.21; P,
5.88. Found: C, 52.28; H, 4.33; P, 5.93%.
C11H14AuP (374.17 g molꢀ1): C, 35.31; H, 3.77. Found:
C, 35.87; H, 3.62%.
6. Crystal structure determinations
5.1.11.
Me3PAu(CCPh)
2-Phenylethynyl(trimethylphosphine)gold(I),
Specimens of suitable quality and size were mounted
on the ends of quartz fibres in F06206R oil and used for
intensity data collection on a Nonius diffractometer,
employing graphite-monochromated Mo Ka radiation.
Intensity data were corrected for absorption effects (DE-
LABS from PLATON). The structures were solved by a
combination of direct methods (SHELXS-97) and differ-
ence-Fourier syntheses and refined by full-matrix least-
squares calculations on F2 (SHELXL-97) [74]. The ther-
mal motion of all non-hydrogen atoms except for C31
of one of the monomers of Me3PAu(CCPh) was treated
anisotropically. Apart from the acetylenic hydrogen
atoms of cis-Ph3PAuMe2(CCH) and [(p-Tol3)-
P]Au(CCH), which were found and refined isotropically,
all hydrogen atoms were calculated and allowed to ride
on their parent atoms with fixed isotropic contributions.
Further information on crystal data, data collection and
structure refinement are summarized in Tables 1–3.
Important interatomic distances and angles are shown
in the corresponding figure captions. Anisotropic ther-
mal parameters and tables of interatomic distances
and angles have been deposited with the Cambridge
Crystallographic Data Centre, 12 Union Road,
1.6 ml of a solution of LiCCPh in THF (1.6 mmol,
1.0 M) was added dropwise to a suspension of 500 mg
(1.6 mmol) of (Ph3P)AuCl in THF at ꢀ78 ꢀC. The mix-
ture was allowed to warm to room temperature and stir-
red for 1 h. Degassed water was added to destroy traces
of the lithium reagent. Subsequently, the solvents were
evaporated under reduced pressure. The residue was
redissolved in dichloromethane and LiCl removed by
extraction with 3 · 20 ml of water. After filtration of
the organic phase through anhydrous MgSO4, n-pen-
tane was added and 455 mg (75% yield) of colourless
1
crystals were obtained; m.p. (dec.): 157 ꢀC. H NMR
2
(CD2Cl2, RT): d = 1.54 [d, JHP = 10.3 Hz, 9H,
P(CH3)3], 7.16–7.47 [m, 5H, C6H5]. 13C{1H} NMR
1
(CD2Cl2, RT): d = 15.9 [d, JCP = 35.8 Hz, P(CH3)3],
104.3 [s, Au–C„C–C6H5], 125.9 [s, i-C2(C6H5)], 126.9
[s, o-C2(C6H5)], 128.4 [s, p-C2(C6H5)], 132.3 [s, m-
C2(C6H5)], Au–C„C–C6H5 was not observed. 31P{1H}
NMR (CD2Cl2, RT): d = 1.25 [s]. IR (KBr) [cmꢀ1]:
694 (s), 758 (s), d (Ar, monosubst.); 1417 (s), 1483 (s),
1594 (s), m(C‚C, aromat.); 2105 (m), m(C„C); 2900
(m), m(C–H); 3070 (m), (Ar–H). Anal. Calc. for

1440
O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
[26] L.K. Myers, D.M. Ho, M.E. Thompson, Polyhedron 14 (1995)
57.
Cambridge CB2 1EZ, UK. The data are available on re-
quest on quoting CCDC-244555-61.
[27] L.K. Myers, C. Langhoff, M.E. Thompson, J. Am. Chem. Soc.
114 (1992) 7560.
[28] I.R. Whittall, M.G. Humphrey, M. Samoc, J. Swiatkiewicz, B.
Luther-Davies, Organometallics 14 (1995) 5493.
[29] I.R. Whittall, M.P. Cifuentes, M.G. Humphrey, B. Luther-
Davies, M. Samoc, S. Houbrechts, A. Persoons, G.A. Heath,
D.C.R. Hockless, J. Organomet. Chem. 549 (1997) 127.
[30] A.M. McDonagh, M.G. Humphrey, M. Samoc, B. Luther-Davies,
S. Houbrechts, T. Wada, H. Sasabe, A. Persoons, J. Am. Chem.
Soc. 121 (1999) 1405.
Acknowledgements
This work was generously supported by Deutsche
Forschungsgemeinschaft, Volkswagenstiftung, Fonds
der Chemischen Industrie, and Heraeus GmbH.
[31] I.R. Whittall, M.P. Cifuentes, M.G. Humphrey, B. Luther-
Davies, M. Samoc, S. Houbrechts, A. Persoons, G.A. Heath, D.
Bogsanyi, Organometallics 16 (1997) 2631.
References
[32] C.C. Frazier, E.A. Chauchard, M.P. Cockerham, P.L. Porter,
Mater. Res. Soc., Symp. Proc. 109 (1988) 323.
[1] R.-Y. Liau, A. Schier, H. Schmidbaur, Organometallics 22 (2003)
3199.
[33] P.L. Porter, S. Guha, K. Kang, C.C. Frazier, Polymer 32 (1991)
1756.
[2] G.E. Coates, C. Parkin, J. Chem. Soc. (1962) 3220.
[3] G.E. Coates, C. Parkin, J. Chem. Soc. (1963) 421.
[4] C.M. Mitchell, F.G.A. Stone, J. Chem. Soc., Dalton Trans. (1972)
102.
[34] R.H. Naulty, M.P. Cifuentes, M.G. Humphrey, S. Houbrechts,
C. Boutton, A. Persoons, G.A. Heath, D.C.R. Hockless, B.
Luther-Davies, M. Samoc, J. Chem. Soc., Dalton Trans. (1997)
4167.
[5] C.M. Mitchell, F.G.A. Stone, J. Chem. Soc., Chem. Commun.
(1970) 1263.
[35] X. Hong, K.-K. Cheung, C.-X. Guo, C.-M. Che, J. Chem. Soc.,
Dalton Trans. (1994) 1867.
[6] H. Schmidbaur, in: A. Slawisch (Ed.), Gmelin Handbuch der
anorganischen Chemie, Springer, Berlin, 1980.
[7] H. Schmidbaur, A. Grohmann, M.E. Olmos, in: H. Schmidbaur
(Ed.), Gold: Progress in Chemistry, Biochemistry and Technol-
ogy, Wiley, Chichester, 1999.
[36] V.W.-W. Yam, S.W.-K. Choi, K.-K. Cheung, J. Chem. Soc.,
Dalton Trans. (1996) 3411.
[37] H. Xiao, Y.-X. Weng, S.-M. Peng, C.-M. Che, J. Chem. Soc.,
Dalton Trans. (1996) 3155.
[38] I.R. Whittall, M.G. Humphrey, S. Houbrechts, A. Persoons,
D.C.R. Hockless, Organometallics 15 (1996) 5738.
[39] I.R. Whittall, M.G. Humphrey, D.C.R. Hockless, B.W. Skelton,
A.H. White, Organometallics 14 (1995) 3970.
[8] A. Johnson, R.J. Puddephatt, J. Chem. Soc., Dalton Trans. (1977)
1384.
[9] A. Johnson, R.J. Puddephatt, J.L. Quirk, J. Chem. Soc., Chem.
Commun. (1972) 938.
[40] A.M. McDonagh, I.R. Whittall, M.G. Humphrey, B.W. Skelton,
A.H. White, J. Organomet. Chem. 519 (1996) 229.
[41] A.M. McDonagh, I.R. Whittall, M.G. Humphrey, D.C.R.
Hockless, B.W. Skelton, A.H. White, J. Organomet. Chem. 523
(1996) 33.
[10] S. Komiya, S. Ozaki, A. Shibue, J. Chem. Soc., Chem. Commun.
(1986) 1555.
[11] J. Benito, J.R. Berenguer, J. Fornies, B. Gil, J. Gomez, E.
Lalinde, Dalton Trans. (2003) 4331.
[12] J. Manna, K.D. John, M.D. Hopkins, Adv. Organomet. Chem.
38 (1995) 79.
[42] T.B. Marder, G. Lesley, Z. Yuan, H.B. Fyfe, P. Chow, G.
Stringer, I.R. Jobe, N.J. Taylor, I.D. Williams, S.K. Kurtz, in:
S.R. Marder, J.E. Sohn, G.D. Stucky (Eds.), Materials for
Nonlinear Optics: Chemical Perspectives, American Chemical
Society, Washington, DC, 1991, p. 605.
[13] J. Fornies, E. Lalinde, J. Chem. Soc., Dalton Trans. (1996)
2587.
[14] H. Lang, D.S.A. George, G. Rheinwald, Coord. Chem. Rev. 206–
207 (2000) 101.
[43] H.B. Fyfe, M. Mlekuz, G. Stringer, N.J. Taylor, T.B. Marder, in:
R.M. Laine (Ed.), Inorganic and Organometallic Polymers with
Special Properties, Kluwer, Dordrecht, 1992, p. 331.
[44] A.P. Davey, H. Page, W. Blau, H.J. Byrne, D.J. Cardin, Synth.
Met. 57 (1993) 3980.
[15] K. Osakada, T. Yamamoto, Coord. Chem. Rev. 198 (2000) 379.
[16] U. Belluco, R. Bertani, R.A. Michelin, M. Mozzon, J. Organomet.
Chem. 600 (2000) 37.
[17] I.R. Whittall, A.M. McDonagh, M.G. Humphrey, M. Samoc,
Adv. Organomet. Chem. 42 (1998) 291.
[45] A.P. Davey, D.J. Cardin, H.J. Byrne, W. Blau, in: J. Messier, F.
Kajzar, P. Prasad (Eds.), Organic Molecules for Nonlinear Optics
and Photonics, Kluwer, Dordrecht, 1991, p. 391.
[46] H. Page, W. Blau, A.P. Davey, X. Lou, D.J. Cardin, Synth. Met.
63 (1994) 179.
[18] Y. Liu, S. Jiang, K. Glusac, D.H. Powell, D.F. Anderson, K.S.
Schanze, J. Am. Chem. Soc. 124 (2002) 12412.
[19] N.J. Long, A.J.P. White, D.J. Williams, M. Younus, J. Organ-
omet. Chem. 649 (2002) 94.
[20] P. Siemsen, U. Gubler, C. Bosshard, P. Gunter, F. Diederich,
Chem. Eur. J. 7 (2001) 1333.
[47] I.R. Whittall, M.G. Humphrey, A. Persoons, S. Houbrechts,
Organometallics 15 (1996) 1935.
[21] M.S. Khan, M.R.A. Al-Mandhary, M.K. Al-Suti, A.K. Hisahm,
P.R. Raithby, B. Ahrens, M.F. Mahon, L. Male, E.A. Marseglia,
E. Tedesco, R.H. Friend, A. Koehler, N. Feeder, S.J. Teat, J.
Chem. Soc., Dalton Trans. (2002) 1358.
[48] I.R. Whittall, A.M. McDonagh, M.G. Humphrey, M. Samoc,
Adv. Organomet. Chem. 43 (1998) 349.
[49] M.J. Irwin, J.J. Vittal, R.J. Puddephatt, Organometallics 16
(1997) 3541.
[22] J. Vicente, M.T. Chicote, M.D. Abrisqueta, M.C. Ramirez de
Arellano, P.G. Jones, M.G. Humphrey, M.P. Cifuentes, M.
Samoc, B. Luther-Davies, Organometallics 19 (2000) 2968.
[23] V.W.-W. Yam, S.W.-K. Choi, J. Chem. Soc., Dalton Trans.
(1996) 4227.
[50] S.-J. Shieh, X. Hong, S.-M. Peng, C.-M. Che, J. Chem. Soc.,
Dalton Trans. (1994) 3067.
[51] C.M. Che, H.K. Yip, W.T. Wong, T.F. Lai, Inorg. Chim. Acta
197 (1992) 177.
[52] H. Xiao, K.-K. Cheung, C.-M. Che, J. Chem. Soc., Dalton Trans.
(1996) 3699.
[24] I.R. Whittall, M.G. Humphrey, M. Samoc, B. Luther-Davies,
Angew. Chem., Int. Ed. Engl. 36 (1997) 370.
[53] B.-C. Tzeng, W.-C. Lo, C.-M. Che, S.-M. Peng, Chem. Commun.
(Cambridge, UK) (1996) 181.
[25] M.E. Thompson, W. Chiang, L.K. Myers, C. Langhoff, Proc.
SPIE Int. Soc. Opt. Eng. 1497 (1991) 423.

O. Schuster et al. / Inorganica Chimica Acta 358 (2005) 1429–1441
1441
[54] D. Li, X. Hong, C.M. Che, W.C. Lo, S.M. Peng, J. Chem. Soc.,
Dalton Trans. (1993) 2929.
[65] M. Paul, H. Schmidbaur, Z. Naturforsch. B 49 (1994) 647.
[66] A. Shiotani, H. Schmidbaur, Chem. Ber. 104 (1971) 2838.
[55] C.M. Che, H.K. Yip, W.C. Lo, S.M. Peng, Polyhedron 13 (1994)
887.
[67] J. Stein, J.P. Fackler, Jr., C. Paparizos, H.W. Chen, J. Am.
Chem. Soc. 103 (1981) 2192.
[56] C. King, J.C. Wang, M.N.I. Khan, J.P. Fackler Jr., Inorg. Chem.
28 (1989) 2145.
[68] K.M.-C. Wong, C.-K. Hui, K.-L. Yu, V.W.-W. Yam, Coord.
Chem. Rev. 229 (2002) 123.
[57] Z. Assefa, R.J. Staples, J.P. Fackler Jr., Inorg. Chem. 33 (1994)
2790.
[69] I.V. Novozhilova, A.V. Volkov, P. Coppens, J. Am. Chem. Soc.
125 (2003) 1079.
[58] S. Komiya, J.K. Kochi, J. Am. Chem. Soc. 98 (1976) 7599.
[59] F.H. Brain, C.S. Gibson, J. Chem. Soc. (1939) 762.
[60] G.C. Stocco, R.S. Tobias, J. Am. Chem. Soc. 93 (1971) 5057.
[61] R.S. Tobias, S.W. Krauhs, G.C. Stocco, Inorg. Chem. 10 (1971)
1365.
[70] R.C. Bott, P.C. Healy, G. Smith, Aust. J. Chem. 57 (2004)
213.
[71] R. Uson, A. Laguna, J. Vicente, J. Organomet. Chem. 131 (1977)
471.
[72] K. Angermaier, E. Zeller, H. Schmidbaur, J. Organomet. Chem.
472 (1994) 371.
[62] A. Tamaki, J.K. Kochi, J. Chem. Soc., Dalton Trans. (1973) 2620.
[63] H. Uchida, N. Saito, K. Ogi (Mitsubishi Materials Corporation,
Japan), Jpn. Kokai Tokkyo Koho, JP 06107670 (1994) Japan.
[64] H.W. Chen, C. Paparizos, J.P. Fackler Jr., Inorg. Chim. Acta 96
(1985) 137.
[73] R. Roulet, L. Nguyen Quang, W.R. Mason, G.P. Fenske Jr.,
Helv. Chim. Acta 56 (1973) 2405.
[74] G.M. Sheldrick, SHELXL-97: Programs for Crystal Structure
Analysis, University of Go¨ttingen, Go¨ttingen, Germany, 1997.