Mono- and bimetallic gold(I) and silver(I) pentafluoropropionates and related compounds

Article abstract of DOI:10.1016/S0020-1693(03)00468-7

A series of eight new carboxylate complexes of the general type (L) _nMOC(O)R (L=PMe₃; n=1; M=Ag, Au; R=C₂F ₅. L=PPh₃; n=1-3; M=Ag; R=C₂F₅, t-Bu) have been prepared in high yields

Full text of DOI:10.1016/S0020-1693(03)00468-7

Inorganica Chimica Acta 357 (2004) 235–242
www.elsevier.com/locate/ica
Mono- and bimetallic gold(I) and silver(I)
pentafluoropropionates and related compounds
*
€
Patric Rombke, Annette Schier, Hubert Schmidbaur , Stefanie Cronje,
*
Helgard Raubenheimer
Anorganisch-chemisches Institut der Technischen Universit€at M€unchen, Lichtenbergstrasse 4, 85747 Garching, Germany
Department of Chemistry, University of Stellenbosch, Matieland, South Africa
Received 27 June 2003; accepted 5 July 2003
Abstract
A series of eight new carboxylate complexes of the general type (L)nMOC(O)R (L ¼ PMe3; n ¼ 1; M ¼ Ag, Au; R ¼ C2F5.
L ¼ PPh3; n ¼ 1–3; M ¼ Ag; R ¼ C2F5, t-Bu) have been prepared in high yields. Crystal and molecular structures have been de-
termined for three representative examples. The crystal structure of (Ph3P)AgOC(O)C2F5 contains dimers in which the silver atoms
are bridged by the carboxylate oxygen atoms. This bridging resembles the structural motif found in silver carboxylates without
ligand support. Usage of the smaller phosphine PMe3 leads to the formation of a polymeric chain structure in (Me3P)AgOC(O)C2F5
with bridging carboxylate anions and short Ag–Ag contacts holding the monomers together. The reaction of (4-Me2N-C6H4)Ph2
PAuCl with two equivalents of C2F5CO2Ag leads to the formation of a mixed metal product containing both gold and silver. The
crystal structure analysis of this compound revealed a tetranuclear complex containing a central dimeric silver pentafluoropropi-
onate unit which is chelated by the (triarylphosphine)gold(I) pentafluoropropionate molecules via Ag–Au metallophilic contacts and
Ag–O donor/acceptor interactions.
Ó 2003 Elsevier B.V. All rights reserved.
Keywords: Gold complexes; Silver complexes; Argentophilicity; Mixed metal metallophilicity; Carboxylate complexes
1. Introduction
nation for the finding that the ‘‘metallophilic’’ bonding
is strongest and therefore most obvious for heavy metals
in general, and for gold complexes in particular [5].
Notwithstanding, there has also been growing evidence
for weak metallophilic bonding between low-coordinate
silver atoms [6] and – as a logical consequence – for
gold–silver metallophilicity [7]. In the present report we
present new and noteworthy examples taken from the
important class of silver and gold perfluorocarboxylates.
These compounds have interesting photophysical prop-
erties [6c] and are relevant to homogeneous gold catal-
ysis [8] and to gold/silver thin film technology [9].
Previous structural studies of (phosphine)gold(I)
perfluorocarboxylates have shown that these com-
pounds are isolated monomers of the type A or Au–Au
bonded dimers of the type A2 depending on the steric
effect of the tertiary phosphine employed [8a,8b]. In
both forms the gold atoms are linearly two-coordinate
with monohapto carboxylate groups. By contrast, in the
The concept of ‘‘metallophilic bonding’’ has added a
new range of intermolecular interactions to the spectrum
of chemical bonding in supramolecular aggregates [1]. A
small number of scattered observations in the early
structural chemistry of gold(I) complexes [2] has grown
into a wealth of reports on related phenomena in the last
two decades, which finally provided a clear pattern of
the conditions under which direct interactions between
closed-shell gold(I) centers can contribute significantly
to the stability of molecular and multidimensional
structures [3]. The underlying ‘‘aurophilic’’ bonding [4]
has been analyzed in theoretical studies which have
confirmed the experimental results and gave an expla-
* Corresponding authors. Tel.: +49-89-289-3130; fax: +49-89-289-
3125.
E-mail address: h.schmidbaur@lrz.tum.de (H. Schmidbaur).
0020-1693/$ - see front matter Ó 2003 Elsevier B.V. All rights reserved.
doi:10.1016/S0020-1693(03)00468-7

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P. Ro€mbke et al. / Inorganica Chimica Acta 357 (2004) 235–242
corresponding (phosphine)silver(I) perfluorocarboxy-
lates the coordination number of the metal atoms can be
expanded with the carboxylate groups becoming O,O0-
dihapto bridges between the metal atoms (B) [6c]. Do-
nor-free silver(I) perfluorocarboxylates are known to be
cyclic dimers of type C in the solid state (Scheme 1) [10].
C2F5CO2Ag þ Me3P ! ðMe3PÞAgOCðOÞC2F5
C2F5CO2Ag þ Ph3P ! ðPh3PÞAgOCðOÞC2F5
ð4Þ
ð5Þ
ð6Þ
ð7Þ
C2F5CO2Ag þ 2 Ph3P ! ðPh3PÞ AgOCðOÞC2F5
2
C2F5CO2Ag þ 3 Ph3P ! ðPh3PÞ AgOCðOÞC2F5
3
Silver pentafluoropropionate is readily dissolved in a
mixture of ethanol and dichloromethane (1:2 by volume)
upon addition of a solution of one equivalent of trim-
ethylphosphine in toluene. Colorless crystals, m.p. 151
°C, can be grown from dichloromethane/pentane at )70
°C (85.7% yield) [Eq. (4)]. A colorless, crystalline tri-
phenylphosphine complex (m.p. 208 °C) was obtained
similarly (from dichloromethane, 91% yield) [Eq. (5)].
With two or three equivalents of Ph3P the corresponding
2:1 and 3:1 complexes could be isolated [Eqs. (6), (7)].
The latter was obtained as single crystals and its struc-
ture has been determined (below).
In order to be able to compare the properties of the
perfluorinated silver carboxylates and alkylated coun-
terparts, the three related mono-, bis- and tris(triphe-
nylphosphine)silver(I) pivalates were also prepared. The
compounds were all obtained in high yields and found
to be stable colorless solids which dissolve readily in
polar solvents. The solutions are light-sensitive and de-
2. Preparative results
Triaryl phosphine complexes of gold(I) pentafluoro-
propionate were synthesized and structurally charac-
terized in a previous study in this laboratory. Owing to
the steric bulk of the phosphines, the compounds are
monomers with a molecular structure of type A [8a].
(Trimethyl phosphine)gold(I) pentafluoropropionate has
now been prepared from the chloride complex and silver
pentafluoropropionate in dichloromethane at )70 °C in
good yield (70.8%) [Eq. (1)], but the product proved
unstable in solution where it decomposed slowly at
temperatures above )30 °C. It could therefore not be
crystallized and its structure – most probably an oligo-
mer with short aurophilic contacts as already demon-
strated [8b] for the trifluoroacetate – could not be
determined. The compound was identified by elemental
analysis, NMR spectroscopy and mass spectrometry.
ðMe PÞAuCl þ C F CO Ag
ðMe PÞAuOCðOÞC F
ð1Þ
ꢀꢀ!
3
2
5
2
3
2
5
ꢀAgCl
½ð4-Me N–C H ÞPh PꢁAuCl þC F CO Ag ½ð4-Me N–C H ÞPh PꢁAuOCðOÞC F
ꢀꢀꢀꢀꢀ!
ð2Þ
ð3aÞ
ð3bÞ
2
5
2
2
6
4
2
2
6
4
2
2
5
ꢀAgCl
2½ð4-Me N–C H ÞPh PꢁAuCl þ4C F CO Ag Au Ag ½ð4-Me N–C H ÞPh Pꢁ ½OCðOÞC F ꢁ
ꢀꢀꢀꢀꢀꢀ!
2
5
2
2
6
4
2
2
2
6
4
2
2
5
4
2
2
ꢀ2AgCl
2ðR3PÞAuOCðOÞC2F5 þ2C F CO Ag Au2Ag ðR3PÞ ½OCðOÞC2F5ꢁ
ꢀꢀꢀꢀꢀ!
2
5
2
2
2
4
compose slowly upon standing at room temperature.
The stoichiometry and general properties thus showed
no anomalies.
R3P ¼ ð4-Me2N–C6H4ÞPh2P
Pure products of type A are only obtained if the stoi-
chiometric ratio of the components (R3P)AuCl and
AgOC(O)C2F5 is strictly 1:1. Under these stringent
conditions, the 1:1 complex with (4-Me2N–C6H4)Ph2P
has been prepared previously without any difficulties
[Eq. (2)] [8a]. However, if an excess of AgOC(O)C2F5 is
employed, mixed-metal products containing both gold
and silver are formed which can only be crystallized as
the molar ratio 1:2 is reached. The compound with di-
phenyl(4-dimethylamino-phenyl)phosphine as a ligand
could be obtained as single crystals [Eq. (3a)] and was
amenable to a diffraction study (below). This product is
obtained in even higher yield from an addition of LAuX
to AgX in the molar ratio 1:1 [Eq. (3b)].
3. Structural studies
(Trimethylphosphine)silver(I) pentafluoropropionate
crystallizes in the monoclinic space group C2=c with
Z ¼ 16 formula units in the unit cell. The asymmetric
unit contains two independent molecules with similar
geometrical parameters. These monomers are aggre-
gated into chains with the two independent units (con-
taining the silver atoms Ag1 and Ag2) alternating along
the chain as shown in Fig. 1. Neighbouring silver atoms
are bridged by pentafluoropropionate groups and

P. R€ombke et al. / Inorganica Chimica Acta 357 (2004) 235–242
237
359.4(1)°, respectively. Of the two sets of three angles,
P1–Ag1–O3 and P2–Ag2–O2 are the largest at 155.6(1)
and 160.5(1)°, representing the distorted molecular axis
of the individual unit. The Ag–Ag contacts extend above
and below the P–Ag–O2 planes in an almost linear ge-
ometry with angles Ag1–Ag2–Ag10 163.57(1)° and Ag2–
Ag1–Ag20 162.39(1)°.
Double-bridging by carboxylate groups of a pair of
metal atoms entertaining argentophilic contacts was also
encountered in the crystals of (Ph3P)Ag–OC(O)C2F5
(monoclinic, space group P21=c, Z ¼ 8, two independent
formula units in the asymmetric unit). However, the
association for this complex is limited to dimers (Fig. 2)
instead of linear polymers. The bulk of the larger Ph3P
ligand requires more space than the small Me3P ligand,
and this requirement is better fulfilled at the small oli-
gomer. Ag2 has a planar T-shaped geometry, while Ag1
has a planar distorted Y-shaped coordination pattern.
ꢀ
The Ag1–Ag2 distance of 3.553(1) A is longer than in the
Me3P complex, probably owing to the steric effect of the
two Ph3P groups.
The crystal structures of (R3P)Ag–OC(O)C2F5 com-
pounds (R ¼ Me, Ph) with three-coordinate metal atoms
bridged – at approximately right angles (Fig. 1) – by
carboxylate groups, and short argentophilic contacts, is
entirely different from that of the analogous gold(I)
complexes which were found to be associated solely
via aurophilic contacts between strictly linearly two-
coordinate metal atoms [8a,8b].
Scheme 1.
maintain short argentophilic contacts [Ag1–Ag2
0
ꢀ
2.8914(5), Ag1–Ag2 2.8652(5) A].
Each silver atom is three-coordinate with a phos-
phorus atom and two oxygen atoms in a common plane,
but the P–Ag–O and O–Ag–O angles show that the
geometry is closer to T-shaped than to trigonal planar.
The sums of angles at Ag1 and Ag2 are 359.6(1)° and
The association of (phosphine)silver(I) pentafluoro-
propionates is absent in the complexes with more than
one phosphine ligand per metal atom. An example in
Fig. 1. Chain structure of AgOCOC2F5 ꢂ PMe3 (ORTEP drawing with 50% probability ellipsoids, H-atoms omitted for clarity). Selected bond lengths
ꢀ
[A] and angles [°]: Ag1–O1 2.400(3), Ag1–P1 2.347(1), Ag1–O3 2.197(3), Ag2A–O2A 2.194(3), Ag2A–P2A 2.343(1), Ag2A–O4 2.438(4), Ag1 ꢂ ꢂ ꢂ Ag2
2.8914(5), Ag1 ꢂ ꢂ ꢂ Ag2A 2.8652(5); O3–Ag1–P1 155.6(1), O3–Ag1–O1 90.6(1), P1–Ag1–O1 113.3(1), O3–Ag1 ꢂ ꢂ ꢂ Ag2A 84.1(1), P1–Ag1 ꢂ ꢂ ꢂ Ag2A
94.75(3), O1–Ag1 ꢂ ꢂ ꢂ Ag2A 102.1(1), O3–Ag1 ꢂ ꢂ ꢂ Ag2 78.3(1), P1–Ag1 ꢂ ꢂ ꢂ Ag2 100.86(3), O1–Ag1 ꢂ ꢂ ꢂ Ag2 79.2(1), Ag2A ꢂ ꢂ ꢂ Ag1 ꢂ ꢂ ꢂ Ag2 162.39(1),
O2A–Ag2A–P2A 160.5(1), O2A–Ag2A–O4 87.0(1), P2A–Ag2A–O4 111.8(1), O2A–Ag2A ꢂ ꢂ ꢂ Ag1 79.6(1), P2A–Ag2A ꢂ ꢂ ꢂ Ag1 97.79(3), O4–
Ag2A ꢂ ꢂ ꢂ Ag1 80.1(1), O2A–Ag2A ꢂ ꢂ ꢂ Ag1A 84.2(1), P2A–Ag2A ꢂ ꢂ ꢂ Ag1A 98.45(3), O4–Ag2A ꢂ ꢂ ꢂ Ag1A 96.1(1), Ag1A ꢂ ꢂ ꢂ Ag2A ꢂ ꢂ ꢂ Ag1 163.57(1).

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P. Ro€mbke et al. / Inorganica Chimica Acta 357 (2004) 235–242
case is the structure of (Ph3P)3Ag–OC(O)C2F5 which
crystallizes as the tetrahydrofuran solvate (triclinic,
ꢁ
space group P1, Z ¼ 2). The tetrahydrofuran molecule
in this phase is disordered near a center of inversion.
The asymmetric unit contains one chiral formula unit
(Fig. 3) which is related with its enantiomer by a center
of inversion. The silver atom is tetracoordinate with a
quasi-tetrahedral coordination geometry. The pentaflu-
oropropionate group is g1-bonded to the metal with an
ꢀ
Ag–O1 distance of 2.433(2) A.
The most interesting structural aspect in this report is
the arrangement of the components of the mixed-metal
tetranuclear compound L2Au2Ag2X2 or (AgX)2
(LAuX)2 [X ¼ C2F5CO2; L ¼ (4-Me2N–C6H4)Ph2P].
ꢁ
This adduct crystallizes in the triclinic space group P1
with Z ¼ 1 formula unit in the unit cell. The asymmetric
unit contains half of the tetranuclear complex, the other
half being related by a center of inversion (Fig. 4). The
aggregate has a neutral dimer [C2F5CO2Ag]2 as a core
unit with a planar eight-membered ring already familiar
from previous studies of silver carboxylates [10]. It
should be noted that this dimer has a short argentophilic
Fig. 2. Dimeric structure of AgOCOC2F5 ꢂ PPh3 (ORTEP drawing
with 50% probability ellipsoids, H-atoms omitted for clarity). Selected
ꢀ
ꢀ
transannular contact Ag–Ag [2.9939(6) A].
bond lengths [A] and angles [°]: Ag1–O1 2.73(2), Ag1–O3 2.310(2),
Ag1–P1 2.351(1), Ag2–O2 2.362(2), Ag2–O4 2.212(2), Ag2–P2
2.347(1), Ag1 ꢂ ꢂ ꢂ Ag2 3.553(1); O1–Ag1–O3 92.76(8), O1–Ag1–P1
136.87(6), O3–Ag1–P1 130.34(5), O4–Ag2–P2 150.02(6), O4–Ag2–O2
89.14(8), P2–Ag2–O2 117.83(5).
Fig. 4. Structure of tetranuclear [(AgOCOC2F5)2((4-Me2NC6H4)
Ph2PAuOCOC2F5)2] (ORTEP drawing with 50% probability ellip-
ꢀ
soids, H-atoms omitted for clarity). Selected bond lengths [A] and
angles [°]: Au1–O1 2.080(2), Au1–P1 2.2240(8), Au1 ꢂ ꢂ ꢂ Ag1 3.0253(3),
Ag1–O2 2.245(3), Ag1–O3 2.195(3), Ag1–O4 2.204(3), Ag1 ꢂ ꢂ ꢂ Ag1A
2.9439(6); O1–Au1–P1 173.56, O1–Au1 ꢂ ꢂ ꢂ Ag1 86.69(7), P1–
Au1 ꢂ ꢂ ꢂ Ag1 99.08(2), O2–Ag1–O3 110.1(1), O2–Ag1–O4 90.3(1), O3–
Ag1–O4 159.6(1), O2–Ag1 ꢂ ꢂ ꢂ Ag1A 155.72(7), O3–Ag1 ꢂ ꢂ ꢂ Ag1A
82.68(7), O4–Ag1 ꢂ ꢂ ꢂ Ag1A 78.49(8), O2–Ag1 ꢂ ꢂ ꢂ Au1 68.87(6), O3–
Ag1 ꢂ ꢂ ꢂ Au1 103.36(7), O4–Ag1 ꢂ ꢂ ꢂ Au1 83.07(8), Ag1A ꢂ ꢂ ꢂ Ag1 ꢂ ꢂ ꢂ Au1
129.76(2).
Fig. 3. Molecular structure of AgOCOC2F5 ꢂ 3 PPh3 ꢂ 0.5thf (ORTEP
drawing with 50% probability ellipsoids, H-atoms and disordered
ꢀ
solvent molecule omitted for clarity). Selected bond lengths [A] and
angles [°]: Ag1–O1 2.433(2), Ag1–P1 2.6026(8), Ag1–P2 2.5441(7),
Ag1–P3 2.5432(7); O1–Ag1–P1 91.09(7), O1–Ag1–P2 107.50(6), O1–
Ag1–P3 108.67(6), P1–Ag1–P2 112.96(2), P1–Ag1–P3 115.59(2), P2–
Ag1–P3 117.34(3).

P. R€ombke et al. / Inorganica Chimica Acta 357 (2004) 235–242
239
The two L–Au–OC(O)C2F5 molecules are attached to
this core unit via two external metallophilic contacts
5 ml. The product is precipitated by addition of n-pen-
tane (5 ml) at )70 °C, collected and recrystallized from
tetrahydrofuran/pentane to give 250 mg (70.8% yield) of
a colorless solid which decomposes at room tempera-
ture. Solutions in dichloromethane or tetrahydrofuran
ꢀ
Ag–Au [3.0253(2) A] and two silver–oxygen contacts
ꢀ
Ag1–O2 [2.456(3) A]. Each (phosphine)gold perfluoro-
propionate unit is thus chelating a silver atom employ-
ing its metal atom and one carboxylate oxygen atom for
the bite. Consequently, the resulting metal atom chain
Au–Ag–Ag–Au is not linear but has two Au–Ag–Ag
angles of 129.78(2)°.
The coordination of each silver atom by its oxygen
donor atoms is planar T-shaped not unlike the situation
in the oligomeric or dimeric homometallic (phos-
phine)silver(I) pentafluoropropionates described above.
By contrast, the gold atoms remain linearly two-coor-
dinate [P1–Au1–O1 173.56(7)°] with the Au–Ag contacts
perpendicular to the molecular axis [O1–Au1–Ag1
86.69(7)°].
An array of this type was recently also found in a 1:2
adduct of dimeric silver trifluoroacetate and [diphenyl
(phenylthiomethyl)phosphine]pentafluorophenylgold (I)
[7k]. In this case the LAuX units are attached to the
(CF3CO2Ag)2 core unit via Ag–S and Au–Ag contacts.
The Au–Ag and Ag–Ag distances are similar in both
structures. However, in the reference compound the
Au–Ag–Ag–Au chain is not extended but highly bent,
with Au–Ag–Ag angles as small as 71.69(2)° giving it a
‘‘lightning’’ shape. The details of the two structures
thus are consistent in showing the affinity (metallo-
philicity) of linearly two-coordinate silver atoms for
linearly two-coordinate gold atoms, but they also
demonstrate that this affinity has no directional ele-
ment and can occur anywhere in a belt around each
metal.
1
decompose already above )30 °C. NMR (CD2Cl2) H:
2.74 ppm, d, J 11.4 Hz; 31P{1H}: )16.2 ppm, s. MS
(FAB): m=e 436 (6.3%) [M]þ; 349 (4.3) [L2Au]þ; 289
(100) [LAuO]þ; 273 (8.5) [LAu]þ. Elemental analysis
found C 16.2, H 1.9; calcd. for C6H9AuO2PF5 (436.05)
C 16.5, H 2.1%.
4.2. (Trimethylphosphine)silver(I) pentafluoropropio-
nate (2)
A suspension of C2F5CO2Ag (300 mg, 1.11 mmol) in
a mixture of ethanol (5 ml) and dichloromethane (10 ml)
is treated with a solution of Me3P in toluene (1.11 ml,
1.11 mmol) with stirring at room temperature. After 3 h
a clear solution is obtained, which is concentrated in a
vacuum to a volume of ca. 5 ml and cooled to )70 °C.
Addition of cold pentane leads to the precipitation of
the product, which is recrystallized from dichlorome-
thane/pentane to give colorless crystals (330 mg, 85.7%
1
yield), m.p. 151 °C. NMR (CD2Cl2), H: 1.44, d, J 9.8
Hz. 31P{1H}: )34.8, s. MS (FAB): m=e 531 (15.8%)
[L2AgX]þ; 259 (100) [L2Ag]þ; 183 (41.9) [LAg]þ.
4.3. (Triphenylphosphine)silver(I) pentafluoropropionate
(3)
A suspension of C2F5CO2Ag (250 mg, 0.93 mmol) in
10 ml of dichloromethane is treated with a solution of
Ph3P (240 mg, 0.93 mmol) in the same volume of the
same solvent at room temperature. A clear solution is
obtained, the volume of which is reduced to ca. 5 ml in a
vacuum. Addition of cold pentane ()70 °C) gives a
colorless precipitate which is recrystallized from di-
chloromethane/pentane (450 mg, 91% yield), m.p.
4. Experimental
All experiments were carried out in an atmosphere of
dry nitrogen. Glassware was oven-dried and filled with
nitrogen. Solvents were dried, distilled and stored under
nitrogen. Standard equipment was used throughout.
The glass apparatus was protected against light by an
aluminium foil wrapper. The silver pentafluoropropio-
nate and all tertiary phosphines are commercially
available. (Phosphine)gold(I) chlorides were prepared
following literature procedures [11].
1
208 °C. NMR (CDCl3), H: 7.38–7.56, m, Ph; 13C{1H}:
163.2, t, J 25.5 Hz, CO2; CF2 and CF3 were not de-
tected; 128.9, d, J 37.4 Hz; 129.3, d, J 10.1 Hz; 131.5, s;
133.9, d, J 17.0 Hz (for C-ipso, -meta, -para, and -ortho,
resp.); 31P{1H}: 15.4, s. IR (KBr): 1653 cmꢀ1, m(CO).
MS (FAB): m=e 631 (31.1%) [L2Ag]þ; 385 (3.0)
[LAgO]þ; 369 (100) [LAg]þ; 262 (47.5) [L]þ. Elemental
analysis, found C 47.3, H 2.7, P 6.2; calcd. for
C21H15AgO2PF5 (533.17) C 47.3, H 2.8, P 5.8%.
4.1. (Trimethylphosphine)gold(I) pentafluoropropionate
(1)
4.4. Bis(triphenylphosphine)silver(I) pentafluoropropio-
nate (4)
A suspension of C2F5CO2Ag (220 mg, 0.81 mmol) in
dichloromethane (5 ml) is cooled to )70 °C and treated
with a solution of (Me3P)AuCl (250 mg, 0.81 mmol) in
10 ml of CH2Cl2 with stirring. After 2 h the precipitation
of AgCl is complete. The reaction mixture is filtered and
the filtrate concentrated in a vacuum to a volume of ca.
C2F5CO2Ag (200 mg, 0.74 mmol) is suspended in 10
ml of dichloromethane and a solution of Ph3P (387 mg,
1.48 mmol) in the same volume of the same solvent is
slowly added with stirring. After 2 h the solvent is

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P. Ro€mbke et al. / Inorganica Chimica Acta 357 (2004) 235–242
evaporated to leave the product, which is recrystallized
from tetrahydrofuran/pentane; colorless solid (540 mg,
92% yield), m.p. 164 °C with decomposition. NMR
(CD2Cl2), 1H: 7.33–7.51, m, Ph. 13C{1H}: 162.1, t, J
23.7 Hz, CO2; CF2 and CF3 not detected; 129.9, d, J 8.3
Hz; 130.6, s; 133.4, d, J 31.1 Hz, 133.8, d, J 15.6 Hz (for
C-meta, -para, -ipso, and -ortho). 31P{1H}: 8.7, s. MS
(FAB): m=e 631 (82%) [L2Ag]þ; 385 (4.0) [LAgO]þ; 369
(100) [LAg]þ; 262 (54.4) [L]þ. Elemental analysis, found
C 58.9, H 3.8, P 7.7; calcd. for C39H30AgO2P2F5
(795.43) C 58.8, H 3.8, P 7.7%.
with a solution of [(4-Me2N–C6H4)Ph2P]AuOC(O)C2F5
(150 mg, 0.225 mmol) in 10 ml of the same solvent. After
2 h of stirring a clear solution is obtained, which is
concentrated in a vacuum to a volume of ca. 5 ml.
Addition of 10 ml of cold pentane ()70 °C) leads to
precipitation of the product, which is recrystallized from
dichloromethane/pentane (180 mg, 84% yield); colorless,
air-stable crystals (m.p. 86 °C), which decompose slowly
1
in solution in daylight at 20 °C. NMR (CD2Cl2), H:
3.0, s, 6H, Me; 6.74 and 7.36, d, 2H each, C6H4; 7.38–
7.42, m, 10H, Ph. 31P{1H}: 25.4, s. IR (KBr): 1675 and
1645 cmꢀ1, m(C ¼ O). MS (FAB): m=e 807 (32%)
[L2Au+H]þ; 806 (2.0) [L2Au]þ; 518 (1.9) [L2Ag]þ; 502
(100) [LAu]þ; 412 (11.5) [LAg]þ; 304 (88.7) [L]þ. Ele-
mental analysis found C 33.0, H 2.3, N 1.4; calcd. for
C26H20NPAgAuO4F10 (936.2) C 33.3, H 2.1, N 1.5%.
4.5. Tris(triphenylphosphine)silver(I) pentafluoropropio-
nate (5)
The compound is prepared from C2F5CO2Ag (200
mg, 0.74 mmol) and Ph3P (580 mg, 2.22 mmol) in a total
of 30 ml of dichloromethane at 40 °C. After 2 h of
stirring the reaction mixture is concentrated to a small
volume (ca. 8 ml) and cold pentane ()70 °C) is added to
precipitate the colorless product, which is crystallized
from tetrahydrofuran/pentane; 770 mg (98.7% yield),
4.8. (Triphenylphosphine)silver(I) pivalate (2,2-dimeth-
ylpropionate) (8)
Me3CCO2Ag (150 mg, 0.72 mmol) is dissolved in 15
ml of dichloromethane containing Ph3P (190 mg, 0.72
mmol). After 3 h a clear solution is obtained. The sol-
vent is evaporated and the residue washed with diethyl
ether and crystallized from dichloromethane/pentane
(270 mg, 79.6% yield), colorless solid, m.p. 105 °C with
1
m.p. 169 °C with decomposition. NMR (CD2Cl2), H:
7.29–7.69, m, Ph; 13C{1H}: 160.9, t, J 22.4 Hz, CO2;
CF2 and CF3 not detected; 128.7, d, J 9.6; 130.2, s;
133.4, d, J 28.2 Hz; 133.8, d, J 14.7 Hz (C-meta, -para,
-ipso, and -ortho, resp.); 31P{1H}: 5.2, s.MS (FAB): m=e
631 (100) [L2Ag]þ; 385 (2.9) [LAgO]þ; 369 (89.8)
[LAg]þ; 262 (28.2 [L]þ). Elemental analysis, found C
58.5, H 3.9, F 11.7; calcd. for C57H45AgO2P3F 5 (1057.7)
C 58.9, H 3.8, F 11.9%.
1
decomposition. NMR (CD2Cl2), H: 1.20, s, 9H, Me;
7.31–7.64, m, 15H, Ph; 31P{1H}: 14.3, s. MS (FAB): m=e
841 (8.1%) [L2Ag2X]þ; 631 (53.6) [L2Ag]þ; 369 (100)
[LAg]þ; 262 (10.9) [L]þ. Elemental analysis found C
60.5, H 5.2, P 6.6; calcd. for C23H24AgO2P (471.26) C
58.6, H 5.1, P 6.6%.
4.6. [(4-Dimethylamino-phenyl)diphenylphosphine]gold
(I) pentafluoropropionate (6)
4.9. Bis(triphenylphosphine)silver(I) pivalate (9)
[(4-Me2N–C6H4)Ph2P]AuCl (250 mg, 0.46 mmol) is
dissolved in dichloromethane (10 ml) and added to a
suspension of C2F5CO2Ag (130 mg, 0.46 mmol) in 5 ml of
the same solvent with stirring at )70 °C. After 2 h the
AgCl precipitate is filtered off and the filtrate is concen-
trated in a vacuum to a volume of ca. 5 ml. The colorless
product is precipitated by the addition of cold pentane
()70 °C); 270 mg (88% yield), m.p. 132 °C with decom-
As described above for the 1:1 complex, the com-
pound is prepared using Me3CCO2Ag (150 mg, 0.72
mmol) and Ph3P (375 mg, 1.44 mmol) in the molar ratio
1:2; 480 mg (91% yield), m.p. 158 °C with decomposi-
tion. NMR (CD2Cl2), 1H: 1.22, s, 9H, Me; 7.28–7.62, m,
30H, Ph. 13C{1H}: 28.7, s, Me; 39.0, s, C(Me)3; 171.1, s,
CO2; 128.9, d, J 9.3 Hz; 130.3, d, J 1.6 Hz; 132.5, d, J
26.6 Hz; 134.0, d, J 16.6 Hz (for C-meta, -para, -ipso,
and -ortho). 31P{1H}: 9.7, s. MS (FAB): m=e 840 (2.7%)
[L2Ag2X]þ; 631 (29.2) [L2Ag]þ; 369 (100) [LAg]þ; 262
(29.8) [L]þ. Elemental analysis found C 66.7, H 5.2, P
8.5; calcd. for C41H39AgO2P (733.54) C 67.1, H 5.4, P
8.4%.
1
position. NMR (CD2Cl2), H: 3.0, s, 6H, Me; 6.74 and
7.36, d, 2H each, C6H4; 7.38–7.42, m, 10H, Ph. 31P{1H}:
24.84, s. IR (KBr): 1658 cmꢀ1, m(C ¼ O). MS (FAB): m=e
1167 (5.0%) [L2Au2X]þ; 807 (25) [L2Au+H]þ; 806 (1.6)
[L2Au]þ; 665 (7.6) [M]þ; 502 (100) [LAu]þ; 304 (48.9)
[L]þ. Elemental analysis found C 39.8, H 3.0, N 2.0; calcd.
for C23H20AuNO2PF5 (665.3) C 41.5, H 3.0, N 2.1%.
4.10. Tris(triphenylphosphine)silver(I) pivalate (10)
4.7. Bis[(4-dimethylamino-phenyl)diphenylphosphine]di-
gold(I)-disilver(I) tetrakis(pentafluoropropionate) (7)
As described above for the 1:1 and 1:2 complexes, the
compound is obtained from Me3CCO2Ag (200 mg, 0.96
mmol) and Ph3P (760 mg, 2.87 mmol) at 35 °C; 780 mg
(81.8% yield), m.p. 165 °C with decomposition. NMR
C2F5CO2Ag (65 mg, 0.225 mmol) is suspended in
dichloromethane (5 ml), cooled to )70 °C and treated
1
(CD2Cl2), H: 1.44, s, 9H, Me; 7.33–7.82, m, 45H, Ph.

P. R€ombke et al. / Inorganica Chimica Acta 357 (2004) 235–242
241
Table 1
Crystal data, data collection, and structure refinement
AgOCOC2F5 ꢂ PMe3
AgOCOC2F5 ꢂ PPh3
AgOCOC2F5 ꢂ
3PPh3 ꢂ 0.5thf
[(AgOCOC2F5)2((4-
Me2NC6H4)Ph2PAuOCOC2F5)2]
Crystal data
Formula
Mr
Crystal system
C6H9AgF5O2P
346.97
C21H15AuF5O2P
533.17
C59H49AgF5O2:5P3
1093.76
triclinic
C52H40Ag2Au2F20N2O8P2
1872.42
triclinic
monoclinic
C2=c
19.763(1)
11.258(1)
20.960(1)
90
monoclinic
P21=c
11.1020(2)
15.7720(3)
23.4850(3)
90
ꢁ
ꢁ
Space group
ꢀ
P1
P1
a (A)
13.2283(2)
13.9276(2)
14.0641(3)
85.394(1)
75.115(1)
89.420(1)
2496.0(1)
1.455
9.8412(2)
12.1484(2)
13.3469(2)
79.694(1)
88.845(1)
69.417(1)
1468.1(1)
2.118
ꢀ
b (A)
ꢀ
c (A)
a (°)
b (°)
c (°)
V (A )
qcalc (g cmꢀ3
101.099(3)
90
100.355(1)
90
3
ꢀ
4576.2(5)
2.014
16
4045.3(1)
1.751
)
Z
8
2112
2
1120
1
892
F ð000Þ
2688
19.46
l(Mo Ka) (cmꢀ1
)
73.24
5.64
58.10
Data collection
T (°C)
Measured reflections
)130
42,002
)130
142,495
)130
72,545
)130
42,408
Unique reflections
Absorption correction
4887 [Rint ¼ 0:041]
DELABS
0.282/0.729
8333 [Rint ¼ 0:033]
10,354 [Rint ¼ 0:035]
DELABS
0.478/0.831
6089 [Rint ¼ 0:034]
DELABS
0.506/0.843
none
–
T
min=Tmax
Refinement
Refined parameters
Final R values [I P 2rðIÞ]
271
541
613
397
R1
0.0425
0.0980
0.0350
0.0896
0.876/)0.833
2
0.0455
0.1187
0.0263
0.0660
wR2a
q
ꢀ3
ꢀ
fin(max/min) (e A
)
0.876/)0.580
1.101/)3.605
1.004/)1.388
P
P
2
2
1=2
a wR2 ¼ f½ wðFo2 ꢀ Fc2Þ ꢁ= ½wðFo2Þ ꢁg
;
w ¼ 1=½r2ðFo2Þ þ ðapÞ þ bpꢁ; p ¼ ðFo2 þ 2Fc2Þ=3; a ¼ 0:0349 (AgOCOC2F5 ꢂ PMe3), 0.0537 (AgO-
COC2F5 ꢂ PPh3), 0.0631 (AgOCOC2F5 ꢂ 3PPh3 ꢂ 0.5thf), 0.0384 ([(AgOCOC2F5)2((4-Me2NC6H4)Ph2PAuOCOC2F5)2]); b ¼ 13:97 (AgO-
COC2F5 ꢂ PMe3), 4.47 (AgOCOC2F5 ꢂ PPh3), 4.55 (AgOCOC2F5 ꢂ 3PPh3 ꢂ 0.5thf), 0.90 ([(AgOCOC2F5)2((4-Me2NC6H4)Ph2PAuOCOC2F5)2]).
31P{1H}: 8.1, s. MS (FAB): m=e 840 (2.2%) [L2Ag2X]þ;
631 (100) [L2Ag]þ; 369 (91.6) [LAg]þ; 262 (13.9) [L]þ.
Elemental analysis found C 70.4, H 5.3, P 8.9; calcd. for
C59H54AgO2P3 (955.8) C 71.1, H 5.5, P 9.3%.
are summarized in Table 1. Important interatomic
distances and angles are shown in the corresponding
figure captions.
4.11. X-ray crystallography
5. Supplementary material
Specimens of suitable quality and size were mounted
on the ends of quartz fibers in F06206R oil and used
for intensity data collection on a Nonius DIP2020
diffractometer, employing graphite-monochromated
Mo Ka radiation. The structures were solved by a
combination of direct methods (SHELXS-97) and dif-
ference-Fourier syntheses and refined by full matrix
least-squares calculations on F 2 (SHELXL-97). The
thermal motion was treated anisotropically for all non-
hydrogen atoms, except for the disordered solvent
molecule in the lattice of AgOCOC2F5 ꢂ 3PPh3 ꢂ 0.5thf
which was included with fixed positions and fixed iso-
tropic contributions. All hydrogen atoms were calcu-
lated and allowed to ride on their parent atoms with
fixed isotropic contributions. Further information on
crystal data, data collection and structure refinement
Crystallographic data for the structural analyses with
thermal parameters and complete tables of interatomic
distances and angles have been deposited with the
Cambridge Crystallographic Data Centre, 12 Union
Road, Cambridge, CB2 1EZ, UK (fax: +44-1223-336-
033; e-mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk). The data are available on request
on quoting CCDC-213207-213210.
Acknowledgements
The work was supported by Volkswagenstiftung,
Fonds der Chemischen Industrie, Deutsche For-
schungsgemeinschaft, Degussa AG and Heraeus
GmbH.

242
P. Ro€mbke et al. / Inorganica Chimica Acta 357 (2004) 235–242
(d) A. Sladek, H. Schmidbaur, Z. Naturforsch. 52B (1997)
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