Gold(I) dimethyl- and diphenyl-dithiophosphinate complexes

Article abstract of DOI:10.1039/a706033e

In an attempt to carry out polyauration of dithiophosphinate units, diphenyldithiophosphinic acid, Ph₂P(S)SH, was treated with the reagents {[(R′₃P)Au]₃O}⁺BF₄^- to give compounds {Ph₂P[SAu(PR′₃)]₂}⁺BF ₄^- with R′ = Ph, Me or o-tolyl (o-Tol) (1-3). The symmetrical Au ... Au bonded structure of complex 1 was confirmed by a single-crystal X-ray diffraction study. Intercationic contacts are found only between gold and sulfur atoms. The analogous reaction with PhP(S)(SSiMe₃)₂ gave an unstable product of the composition {PhP[SAu(PPh₃)]₃}⁺BF₄^- 4, for which a solution structure with mirror-symmetry is proposed on the basis of low-temperature NMR data. Attempts to polyaurate dimethyldithiophosphinic acid led to cleavage of the P-S bonds with formation of known trigold sulfonium salts. (Phosphine)gold(I) dithiophosphinates Me₂P(S)SAu(PR′₃) were obtained from Me₂P(S)SNa and chloro(phosphine)gold complexes (R′ = Me, Ph or o-Tol, 5-7 respectively). The crystal and molecular structure of compound 5 was determined. In the crystal, the compound forms two crystallographically independent, centrosymmetrical dimers with Au ... Au contacts [3.1152(5) and 3.1466(5) A] between 'crossed' monomers. With (Me₂S)AuCl as a precursor, the product of the reaction with Me₂P(S)SNa was [Me₂P(S)SAu]₂ 8. Compound 8 is a dinuclear complex with an elongated eight-membered ring structure in a chair conformation. The crystal-structure analysis reveals the expected transannular Au ... Au contacts [3.1949(9) A], but no intermolecular contacts are discernible.

Full text of DOI:10.1039/a706033e

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Gold(I) dimethyl- and diphenyl-dithiophosphinate complexes
Max Preisenberger, Andreas Bauer, Annette Schier and Hubert Schmidbaur*
Anorganisch-chemisches Institut der Technischen Universität München, Lichtenbergstrasse 4,
D-85747 Garching, Germany
In an attempt to carry out polyauration of dithiophosphinate units, diphenyldithiophosphinic acid, Ph2P(S)SH,
was treated with the reagents {[(RЈ3P)Au]3O}ϩBF4Ϫ to give compounds {Ph2P[SAu(PRЈ3)]2}ϩBF4Ϫ with RЈ = Ph,
Me or o-tolyl (o-Tol) (1–3). The symmetrical Au ؒ ؒ ؒ Au bonded structure of complex 1 was confirmed by a single-
crystal X-ray diffraction study. Intercationic contacts are found only between gold and sulfur atoms. The
Ϫ
analogous reaction with PhP(S)(SSiMe3)2 gave an unstable product of the composition {PhP[SAu(PPh3)]3}ϩBF4
4, for which a solution structure with mirror-symmetry is proposed on the basis of low-temperature NMR data.
Attempts to polyaurate dimethyldithiophosphinic acid led to cleavage of the P᎐S bonds with formation of
known trigold sulfonium salts. (Phosphine)gold() dithiophosphinates Me2P(S)SAu(PRЈ3) were obtained from
Me2P(S)SNa and chloro(phosphine)gold complexes (RЈ = Me, Ph or o-Tol, 5–7 respectively). The crystal and
molecular structure of compound 5 was determined. In the crystal, the compound forms two crystallographically
independent, centrosymmetrical dimers with Au ؒ ؒ ؒ Au contacts [3.1152(5) and 3.1466(5) Å] between ‘crossed’
monomers. With (Me2S)AuCl as a precursor, the product of the reaction with Me2P(S)SNa was [Me2P(S)SAu]2 8.
Compound 8 is a dinuclear complex with an elongated eight-membered ring structure in a chair conformation.
The crystal-structure analysis reveals the expected transannular Au ؒ ؒ ؒ Au contacts [3.1949(9) Å], but no
intermolecular contacts are discernible.
Most prominent applications of gold chemistry in modern
technology and medicine are based on gold–sulfur com-
pounds.1 Sulfide and thiolate anions, and the anions of various
inorganic and organic thioacids, appear as ligands for gold()
in gilding pastes, components of electroplating baths or of
mixtures for electroless plating, as well as in pharmaceutical
preparations.2,3 Thio-phosphates, -phosphonates and -phos-
phinates in particular were also included in several of the early
studies of the usage of gold() compounds as lubrication
additives.4–7 The determination of the molecular structure of
one of these compounds gave an early example of supramolecu-
lar chemistry based on a phenomenon which is now addressed
as the ‘auriophilicity’ effect and is currently attracting consider-
able interest.8–10
However, it appears that in the past there has not been any
systematic study of the chemistry of gold() dithiophosphin-
ates. Dithiophosphinic acid anions [R2PS2]Ϫ are potential
bidentate ligands and should form efficient clustering centers
for gold() cations. While monoaurated dithiophosphinates and
the related dithiophosphates are well documented, no attempt
to induce polyauration is reported in the literature.11–13 Present
knowledge of the structural chemistry of gold()–sulfur com-
pounds suggests that steric effects play a major role in determin-
ing the supramolecular aggregation of these polynuclear
species.14–21 We have therefore become interested in gold()
complexes with the smallest dialkylphosphinate ligands, for
which there was no information in the literature.22,23 The pres-
ent paper is mainly an account of gold() dimethylphosphinates
with or without auxiliary ligands, but a few diphenylphos-
phinate analogues have also been included. Formal replacement
of an alkyl or aryl substituent in dithiophosphinates by a
sulfide group yields trithiophosphonates. A first example of a
trinuclear complex of these homologues is also included.
prepared in situ and used immediately for reactions with other
substrates. For this purpose the reaction of diphenylphosphine
Ph2PH with elemental sulfur offers a number of advantages.24
We therefore used this method to generate the precursor for the
reactions with aurating agents.
Treatment of a solution of Ph2P(S)SH in dichloromethane at
0 ЊC with
a solution of tris[(triphenylphosphine)gold()]-
oxonium tetrafluoroborate in the molar ratio 3:2 in the pres-
ence of excess NaBF4 leads to a complex reaction mixture,
which contains tris[(triphenylphosphine)gold()]sulfonium
tetrafluoroborate and µ-diphenyldithiophosphinatobis[(tri-
phenylphosphine)gold()] tetrafluoroborate 1 [equation (1)].
NaBF4 ϩ 4 Ph2P(S)SH ϩ 2 {[(RЈ3P)Au]3O}ϩBF4Ϫ →
3 {Ph2P[SAu(PRЈ3)]2}ϩBF4Ϫ ϩ Ph2P(S)SNa ϩ 2 H2O (1)
Crystals of compound 1 can be obtained by crystallization
from dichloromethane–diethyl ether (yield 40%, m.p. 161 ЊC
with decomposition). The analogous reactions with oxonium
salts containing trimethylphosphine or tri(o-tolyl)phosphine
give the corresponding complexes with Me3P and (o-Tol)3P
(o-Tol = C6H4Me-o) as the auxiliary ligands [2: 44%, m.p.
153 ЊC; 3: 39% yield, m.p. 171 ЊC; equation (1)]. Compounds
1–3 have been characterized by their analytical and spectro-
scopic data (Experimental section).
Phenyltrithiophosphonic acid PhP(S)(SH)2
cannot be used
as a reagent owing to its low stability, but its trimethylsilyl
ester is readily available. The reaction with equimolar amounts
of the oxonium salt (with Ph3P ligands) yields compound 4
[equation (2)] as a white solid which is stable below Ϫ40 ЊC, but
PhP(S)(SSiMe3)2 ϩ {[(Ph3P)Au]3O}ϩBF4Ϫ →
{PhP[SAu(PPh3)]3}ϩBF4Ϫ ϩ (Me3Si)2O (2)
Preparative Results
Diphenyldithiophosphinates and phenyltrithiophosphonates
decomposes rapidly in solution. Only preliminary data could be
obtained for this compound. Its 31P-{1H} NMR spectrum (in
CDCl3 at Ϫ20 ЊC) has two resonances in the intensity ratio 1:3,
but at Ϫ60 ЊC the Ph3P resonance is split further into two
signals of relative intensity 1:2 (see Experimental section).
Diphenyldithiophosphinic acid Ph2P(S)SH is a compound of
low thermal stability. Rapid elimination of hydrogen sulfide is
observed at room temperature, and therefore this reagent is best
J. Chem. Soc., Dalton Trans., 1997, Pages 4753–4758
4753

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S
S
AuPR′3
AuPR′3
–
Me2P
BF4
2
+
–
–
+3 {[R′3PAu]3O} BF4
S
Me2P
SNa
+(R′3P)AuCl
–NaCl
+(Me2S)AuCl
–NaCl
Me
S
S
Me
P
Me2P
+(Me2S)AuCl
S
Au
Au
S
Au(PR′3)
+(R′3P)AuCl
S
S
P
Me
R′ = Me 5, Ph 6, o-Tol 7
8
Me
Scheme 1
Fig. 1 Molecular structure of the dinuclear cation of compound 1
with atomic numbering (ORTEP,25 hydrogen atoms omitted). Selected
bond lengths (Å) and angles (Њ): Au(1) ؒ ؒ ؒ Au(2) 3.2385(4), Au(1)᎐S(1)
2.3240(12), Au(2)᎐S(2) 2.3398(11), Au(1)᎐P(1) 2.2568(12), Au(2)᎐P(2)
2.2583(12), P(3)᎐S(1) 2.038(2), P(3)᎐S(2) 2.035(2), Au(2) ؒ ؒ ؒ S(2Ј) 3.595
(Fig. 2); P(1)᎐Au(1)᎐S(1) 168.23(4), P(2)᎐Au(2)᎐S(2) 173.31(4), Au(1)᎐
S(1)᎐P(3) 99.92(6), Au(2)᎐S(2)᎐P(3) 101.86(6), S(1)᎐P(3)᎐S(2) 115.29(7)
These data suggest a fluxional structure with a ground state
configuration as proposed below, but no final conclusion could
be reached as yet.
Ph
S
S
P
in the monoclinic space group P21/c with 4 formula units
and four molecules of CH2Cl2 in the unit cell. The lattice is
composed of independent dichloromethane molecules, dis-
ordered tetrafluoroborate anions and {Ph2P[SAu(PPh3)]2}ϩ
cations, which are related by a crystallographic center of inver-
sion. The cations have no crystallographically imposed sym-
metry, but the structure approaches rather closely the symmetry
requirement of point group C2, with the two-fold axis passing
through the phosphorus atom of the diphenyldithiophos-
phinate group [P(3), Fig. 1]. The two Au(Ph3P) units are
attached to the two different sulfur atoms with P᎐Au᎐S angles
deviating significantly from the ideal angle of 180Њ
[P(1)᎐Au(1)᎐S(1) 168.23(4), P(2)᎐Au(2)᎐S(2) 173.31(4)Њ]. The
two gold atoms are clearly drawn together to reach a distance
of Au(1) ؒ ؒ ؒ Au(2) = 3.2385(4) Å typical for auriophilic bond-
ing. The angles at the sulfur atoms are similar with individual
values of Au(1)᎐S(1)᎐P(3) 99.92(6) and Au(2)᎐S(2)᎐P(3)
101.86(6)Њ. The shortest contacts between the cations are not
associated with distant metal–metal interactions. The gold
atoms are approached by sulfur atoms of neighbouring mol-
ecules instead, but the resulting parallelogram [Au(2)᎐S(2)᎐
Au(2Ј)᎐S(2Ј), Fig. 2] has two very long edges [Au(2) ؒ ؒ ؒ S(2Ј)
3.595(2) Å] not much shorter than the sum of the van der Waals
radii of gold() and sulfur.
Compound 5 crystallizes (from dichloromethane–pentane) in
the monoclinic space group C2/c with 16 formula units in the
unit cell. The lattice contains two independent monomers,
which are associated in pairs, the components of which are
related by a crystallographical two-fold axis. The dimerization
occurs through short gold–gold contacts [Au(1) ؒ ؒ ؒ Au(1Ј)
3.1152(5) Å, Au(2) ؒ ؒ ؒ Au(2Ј) 3.1466(5) Å] (Fig. 3). The two
dimers are almost superimposable and their structural details
are marginally different (see caption to Fig. 3). From the projec-
tion of the molecules down their Au ؒ ؒ ؒ Au bonds the crossing
of the two P᎐Au᎐S axes (like the crossing of swords) in each of
the dimers is easily discernible (Fig. 4). There is ample prece-
dence for this crossed type of interaction in the aggregates of
many other gold () complexes. The packing of the dimers in the
crystal is not associated with any close intermolecular contacts
between gold atoms or between gold and sulfur atoms.
S
–
BF4
Au
Au
Au
PPh3 PPh3 PPh3
Dimethyldithiophosphinates
For the preparation of all derivatives of dimethyldithiophos-
phinic acid, Me2P(S)SH, the sodium salt Me2P(S)SNa was
used. Its reaction with {[(RЈ3P)Au]3O}ϩBF4Ϫ (molar ratio 3:2)
leads only to cleavage products. It thus appears that com-
pounds with methyl substituents undergo more facile cleavage
of P᎐S bonds than their phenyl analogues. However, the reac-
tions of Me2P(S)SNa with the chlorogold() complexes of Me3P,
Ph3P and (o-Tol)3P in tetrahydrofuran afford almost quantit-
ative yields of colorless crystalline products of the composition
Me2P(S)SAu(PRЈ3) with RЈ = Me (5, 94%, m.p. 169 ЊC), Ph
(6, 97%, m.p. 186 ЊC) and o-Tol (7, 96%, m.p. 178 ЊC, all with
decomposition) (Scheme 1). All compounds gave satisfactory
analytical and spectroscopic data (see Experimental section).
The presence of a non-co-ordinated second sulfur atom in
compound 5 seemed to offer a chance for further auration.
Instead, the reaction with (Me2S)AuCl leads to the cyclic
dinuclear complex [Me2P(S)SAu]2 8. When chloro(dimethyl
sulfide)gold() was treated with Me2P(S)SNa this gold()
dimethyldithiophosphinate 8 was also obtained (53% yield,
m.p. 183 ЊC) (Scheme 1). According to crystallographic data,
this compound is a dimer in the solid state, and there is no
reason to assume that dissociation occurs in solution. Owing to
the high symmetry of the dimer, the NMR spectra are very
simple and fully consistent with the proposed structure (see
Experimental section and below). The pattern of the 1H NMR
spectrum (in CD2Cl2) is unchanged in the temperature range
ϩ30 to Ϫ90 ЊC. It appears that the auracycle undergoes rapid
inversion on the NMR time-scale even at very low temperature.
Otherwise the two diastereotopic P-bound methyl groups
would give rise to separate doublet signals.
The Structural Chemistry of Gold(I)
Dithiophosphinates
Compound 8 crystallizes (from dichloromethane–pentane) in
Compound 1 crystallizes (from dichloromethane–diethyl ether)
the orthorhombic space group Pbca with 8 molecules in the
4754
J. Chem. Soc., Dalton Trans., 1997, Pages 4753–4758

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Fig. 4 Projection of compound 5 down its Au ؒ ؒ ؒ Au bond (only one
of the two independent molecules is shown)
Fig. 2 View of the molecular structure of compound 1 showing the
shortest contacts between the cations
Fig. 5 Molecular structure of compound 8 with atomic numbering
(ORTEP,25 hydrogen atoms omitted). Selected bond lengths (Å) and
angles (Њ): Au ؒ ؒ ؒ AuЈ 3.1949(9), Au᎐S(1) 2.303(3), Au᎐S(2) 2.290(3),
S(1)᎐P 2.030(4), S(2)᎐PЈ 2.033(4); S(1)᎐Au᎐S(2) 173.86(11), P᎐S(1)᎐Au
98.5(2), PЈ᎐S(2)᎐Au 102.8(2), S(1)᎐Au᎐AuЈ 95.78(8), S(2)᎐Au᎐AuЈ
90.22(8)
R
R
R
R
R
R
P
P
P
S
S
H2C
S
H2C
CH2
Au
CH2
R
Au
S
Au
S
Au
Au
CH2
R
Au
S
R
H2C
R
P
P
P
R
R
8
10
9
dithiophosphinate anions [Me2PS2]Ϫ are readily mono-aurated
at one of the sulfur atoms using standard (RЈ3P)AuCl reagents
to give (phosphine)gold() dithiophosphinates of the general
formula Me2P(S)SAu(PRЈ3) (RЈ = Me 5, Ph 6, o-Tol 7) (Scheme
1). If PRЈ3 is replaced by the ligand Me2S with better leaving
group properties, there is complete exchange of both Me2S and
Cl. Thus compound 8 is the sole product of the reaction of
[Me2PS2]Ϫ with (Me2S)AuCl, where the poorer dimethyl sulfide
ligand is liberated quantitatively (Scheme 1).
In complexes of the type Me2P(S)SAu(PRЈ3) the gold atom is
attached to only one of the two sulfur atoms. The structural
data obtained for the compound with RЈ = Me (5) provide no
evidence for S,S-chelation. Instead, the individual molecules
with their linear P᎐Au᎐S axis are associated into dimers, with
short Au ؒ ؒ ؒ Au contacts connecting ‘crossed’ monomers (Fig.
3). Similar Au ؒ ؒ ؒ Au contacts are present in the cyclic structure
of the dimer [Me2P(S)SAu]2 8, and again there is neither
internal sulfur chelation of the gold atoms nor are there
any discernible intermolecular gold–sulfur interactions. The
auracycle of compound 8 shows a very pronounced folding,
but the molecules still undergo rapid inversion in solution as
demonstrated in low-temperature NMR experiments. The two
diastereotopic P-bound methyl groups are NMR equivalent
even at Ϫ90 ЊC in dichloromethane solution (Fig. 5).
Fig. 3 Molecular structure of one of the two crystallographically
independent molecules of compound
5 with atomic numbering
(ORTEP,25 hydrogen atoms omitted). Selected bond lengths (Å) and
angles (Њ) (the corresponding values of the second molecule are given in
square brackets): Au(1) ؒ ؒ ؒ Au(1Ј) 3.1152(5) [3.1466(5)], Au(1)᎐S(1)
2.318(2) [2.315(2)], Au(1)᎐P(1) 2.2568(14) [2.2580(14)], S(1)᎐P(2)
2.042(2) [2.049(2)], S(2)᎐P(2) 1.955(2) [1.958(2)]; P(1)᎐Au(1)᎐S(1)
178.53(7) [179.52(6)], P(2)᎐S(1)᎐Au(1) 105.50(8) [105.34(7)]
unit cell. The lattice contains dimeric molecules with a cyclic
structure arising from the symmetrical double-bridging of the
two gold atoms by the dimethyldithiophosphinate groups (Fig.
5). The eight-membered ring is in an elongated chair conform-
ation with a short transannular gold–gold contact [Au ؒ ؒ ؒ AuЈ
3.1949(9) Å], associated with an inward bending of the
S(1)᎐Au᎐S(2) angle to 173.86(11)Њ. Through narrow angles at
the sulfur atoms [P᎐S(1)᎐Au 98.5(2)Њ, PЈ᎐S(2)᎐Au 102.8(2)Њ] the
folding of the chair is very pronounced. Contrary to the related
bis[µ-(diphenyldithiophosphinato)digold()] complex8 there are
no close intermolecular contacts in the lattice.
The gold() dithiophosphinate 8 is an isoelectronic analogue
of the corresponding gold() phosphonium–bis(methylides) 9
discovered about 20 years ago.26 The structures are closely
related and show only very minor differences. Finally, the
‘intermediate’ species with mixed CH2/S bridges (10), prepared
by Mazany and Fackler22 in 1984, are a blend of the two sym-
Conclusion
In the present work it has been demonstrated that dimethyl-
J. Chem. Soc., Dalton Trans., 1997, Pages 4753–4758
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metrical counterparts and follow the same pattern of structure
and bonding.
{Ph2P[SAu(PMe3)]2}؉BF4؊ 2. The synthesis was analogous to
that of 1 with Ph2PH (23 mg, 0.14 mmol), S8 (9 mg, 0.04 mmol),
Ϫ
Attempts to accomplish polyauration of diorganodithio-
phosphinate anions with more powerful aurating agents like the
NaBF4 (100 mg, 0.91 mmol) and {[(Me3P)Au]3O}ϩBF4 (85
mg, 0.14 mmol) to give 54 mg (44%) of 2. The compound is air
stable and soluble in dichloromethane and chloroform, but
insoluble in pentane and diethyl ether. Crystals could be
obtained from dichloromethane solution by layering with pen-
tane, m.p. 153 ЊC (decomp.) (Found: C, 23.30; H, 3.30; S, 6.56.
C19H30Au2BCl2F4P3S2 requires C, 23.30; H, 3.09; S, 6.55%).
NMR (CDCl3): 1H, δ 7.53–8.12 (m, 10 H, Ph), 1.67 [d, J(HP) 11
Hz, 18 H, CH3]; 31P-{1H}, δ 72.7 (s, 1 P, Ph2P), Ϫ3.5 (s, 2 P,
Me3PAu); 13C-{1H}, δ 132.5 (s), 128.8 [d, J(CP) 13], 130.8 [d,
J(CP) 12] (para-, meta-, ortho-C of Ph2P), ipso C atoms were
not observed with certainty, 16.0 [d, J(CP) 39 Hz, AuPMe3].
FAB mass spectrum: m/z 795 (100%, [M]ϩ).
Ϫ
oxonium reagents {[(RЈ3P)Au]3O}ϩBF4 are only successful
with the phenyl compound [Ph2PS2]Ϫ [equation (1)]. The result-
ing dinuclear compound (RЈ = Ph 1) has the two gold atoms
attached to the two different sulfur atoms, but there are close
contacts between these gold centers which clearly stabilize the
overall arrangement of the cation {Ph2P[SAu(PRЈ3)]2}ϩ (Fig.
1). The cations show weak intermolecular interactions via dis-
tant Au ؒ ؒ ؒ S contacts. The analogous reaction of trigold–
oxonium salts with dimethylphosphinate as a nucleophile leads
to P᎐S cleavage and gives trigold–sulfonium salts of the type
{[(RЈ3P)Au]3S}ϩBF4Ϫ. The electronic effects of methyl and
phenyl groups at phosphorus are thus sufficiently different to
induce a quite different course of the auration reaction.
The trimethylsilyl diester of phenyltrithiophosphonic acid
was found to undergo triauration with the oxonium reagent
[equation (2)], but the product (4) is a very unstable species
which undergoes rapid decomposition both in solution and as a
solid. On the basis of the low-temperature 31P NMR spectrum
the compound is assigned a mirror-symmetrical structure in
solution where two of the three sulfur atoms are bridging the
three gold atoms in a symmetrical array, but this proposal is as
yet only tentative.
؊
{Ph2P[SAu{P(o-Tol)3}]2}؉BF4 3. The synthesis was analo-
gous to that of 1 with Ph2PH (43 mg, 0.23 mmol), S8 (15 mg,
0.06 mmol), NaBF4 (100 mg, 0.91 mmol) and {[{(o-Tol)3P}-
Au]3O}ϩBF4Ϫ (249 mg, 0.16 mmol) to give 120 mg (39%) of 3.
The compound is air stable and soluble in dichloromethane and
chloroform, but insoluble in pentane and diethyl ether. Yellow
crystals could be obtained from dichloromethane solution by
layering with diethyl ether, m.p. 171 ЊC (decomp.) (Found: C,
46.13; H, 3.86; S, 3.98. C55H54Au2BCl2F4P3S2 requires C, 46.40;
1
H, 3.82; S, 4.50%). NMR (CDCl3): H, δ 6.84–7.91 (m, 34 H,
aryl H), 2.30 (s, 18 H, Me); 31P-{1H}, δ 67.6 (s, 1 P, Ph2P), 14.0
[s, 2 P, (o-Tol)3PAu]. FAB mass spectrum: m/z 1251 (100, [M]ϩ),
947 (30, [M Ϫ {P(o-Tol)3}]ϩ), 750 (9%, [M Ϫ AuP(o-Tol)3]ϩ).
Experimental
General
؊
{PhP[SAu(PPh3)]3}؉BF4 4. To a solution of PhP(S)(S-
All experiments were carried out under an atmosphere of dry,
purified nitrogen. Glassware was dried and filled with nitrogen,
solvents were distilled and kept under nitrogen; NMR: JEOL-
GX 270 (109.4 MHz), SiMe4 as internal standard, phosphoric
acid as external standard; mass spectrometer: Finnigan MAT
90; microanalyses: in-house analyzers (by combustion tech-
niques). Starting materials were either commercially available
or were prepared following literature procedures: {[(Ph3P)-
SiMe3)2 (58 mg, 0.17 mmol) in dichloromethane (10 ml) were
Ϫ
added {[(Ph3P)Au]3O}ϩBF4 (245 mg, 0.17 mmol) in dichloro-
methane (10 ml) and NaBF4 (100 mg, 0.91 mmol) at Ϫ30 ЊC.
After stirring for 2 h the solution was filtered. Evaporation of
the solvent from the filtrate in vacuo to leave a volume of ca. 5
ml and addition of pentane led to the precipitation of complex
4 as a white solid. The solid compound is stable at Ϫ40 ЊC, but
is unstable in solution. NMR (CDCl3): 1H (Ϫ20 ЊC) δ 7.07–7.32
(m, Ph); 31P-{1H} (Ϫ20 ЊC) δ 86.9 (s, 1 P, PhP), 37.2 (s, 3 P,
AuPPh3); (Ϫ60 ЊC) δ 86.7 (s, 1 P, PhP), 37.4 (s, 1 P, AuPPh3),
36.7 (s, 2 P, AuPPh3). FAB mass spectrum: m/z 1581 (4%, [M]ϩ).
Au]3O}ϩBF4
,
{[(Me3P)Au]3O}ϩBF4
,
{[{(o-Tol)3P}Au]3-
Ϫ 27
Ϫ 28
O}ϩBF4
,
Ph2P(S)SH,24 (Me2S)AuCl,30 (Ph3P)AuCl,31
Ϫ 29
(Me3P)AuCl,28 {(o-Tol)3P}AuCl,32 Me2P(S)SNa,33 PhP(S)-
(SSiMe3)2.34
Me2P(S)SAu(PMe3) 5. To a solution of Me2P(S)SNa (48 mg,
0.32 mmol) in thf (10 ml) was slowly added (Me3P)AuCl (99
mg, 0.32 mmol) dissolved in thf (10 ml). After stirring for 1 h
the solvent was removed in vacuo and the white precipitate was
extracted with dichloromethane (10 ml). Addition of pentane
to the filtrate led to the precipitation of 120 mg (94%) of 5 as a
white solid. The compound is air stable and stable in solution,
soluble in dichloromethane and chloroform, but insoluble in
pentane and diethyl ether. Crystals could be obtained from
dichloromethane solution by layering with pentane, m.p. 169 ЊC
(decomp.) (Found: C, 15.03; H, 3.81; S, 15.94. C5H15AuP2S2
requires C, 15.08; H, 3.80; S, 16.10%). NMR (CDCl3): 1H,
δ 2.13 [d, J(HP) 13, 6 H, P(S)Me2], 1.60 [d, J(HP) 11 Hz, 9 H,
AuPMe3]; 31P-{1H}, δ 60.8 [s, 1 P, Me2P(S)], Ϫ4.2 (s, 1 P,
Me3PAu); 13C-{1H}, δ 33.0 [d, J(CP) 54, Me2P(S)], 15.9 [d,
J(CP) 37 Hz, Me3PAu]. FAB mass spectrum: m/z 398 (66%,
[M]ϩ).
Syntheses
{Ph2P[SAu(PPh3)]2}؉BF4؊ 1. To a solution of S8 (13 mg,
0.053 mmol) in toluene (5 ml) was added Ph2PH (39 mg, 0.21
mmol) dissolved in toluene (5 ml). After stirring for 6 h at
80 ЊC the solvent was removed in vacuo. The remaining green
oil was dissolved in dichloromethane (10 ml) and added at
0 ЊC to a solution of {[(Ph3P)Au]3O}ϩBF4 (209 mg, 0.14
Ϫ
mmol) in dichloromethane (10 ml). After addition of NaBF4
(100 mg, 0.91 mmol) and stirring for 2 h the solution was
filtered. Evaporation of the solvent from the filtrate in vacuo
to leave a volume of ca. 5 ml and addition of diethyl ether
led to the precipitation of a colourless 1:1 mixture of com-
plex 1 and {[(Ph3P)Au]3S}ϩBF4Ϫ. Crystals suitable for X-ray
studies of complex 1 could be obtained from dichloro-
methane solution by layering with diethyl ether (yield 104 mg,
40%), m.p. 161 ЊC (decomp.) (Found: C, 46.12; H, 3.19; S,
4.94. C48H40Au2BF4P3S2 requires C, 45.95; H, 3.21; S,
5.11%). NMR (CDCl3): 1H, δ 7.41–7.89 (m, Ph); 31P-{1H}
(room temperature) δ 70.8 (s, 1 P, Ph2P), 37.1 (s, 2 P,
Ph3PAu); (Ϫ60 ЊC) δ 70.7 [t, J(PP) 10, 1 P, Ph2P], 36.4 [d,
J(PP) 10, 2 P, Ph3PAu]; 13C-{1H}, δ 132.8 (s), 129.0 [d, J(CP)
13], 130.8 [d, J(CP) 12] (para-, meta-, ortho-C of Ph2P), 132.5
[d, J(CP) 3], 129.5 [d, J(CP) 12], 133.9 [d, J(CP) 14 Hz]
(para-, meta-, ortho-C of Ph3PAu), ipso C atoms were not
observed with certainty. FAB mass spectrum: m/z 1168 (28,
[M ϩ 1]ϩ), 905 (22%, [M Ϫ PPh3]ϩ).
Me2P(S)SAu(PPh3) 6. The synthesis was analogous to that
of 5 with Me2P(S)SNa (35 mg, 0.24 mmol) and (Ph3P)AuCl
(117 mg, 0.24 mmol) to give 134 mg (97%) of 6. Crystals could
be obtained from dichloromethane solution by layering with
pentane, m.p. 186 ЊC (decomp.) (Found: C, 42.01; H, 3.91.
C20H21AuP2S2 requires C, 41.10; H, 3.62%). NMR (CDCl3): 1H,
δ 7.15–7.73 (m, 15 H, Ph), 2.14 [d, J(HP) 13 Hz, 6 H, Me]; 31P-
{1H}, δ 57.2 [s, 1 P, Me2P(S)], 35.8 (s, 1 P, Ph3PAu). FAB mass
spectrum: m/z 584 (37%, [M]ϩ).
4756
J. Chem. Soc., Dalton Trans., 1997, Pages 4753–4758

View Article Online
Table 1 Crystal data, data collection, and structure refinement for compounds 1, 5 and 8
1
5
8
Crystal data
Formula
Mr
Crystal system
Space group
C48H40Au2BF4P3S2ؒCH2Cl2
C5H15AuP2S2
398.20
Monoclinic
C2/c
C2H6AuPS2
322.12
Orthorhombic
Pbca
1339.50
Monoclinic
P21/c
a/Å
b/Å
c/Å
α/Њ
13.245(1)
14.576(1)
25.643(1)
90
19.464(2)
12.277(1)
20.626(2)
90
11.093(1)
10.673(1)
11.402(1)
90
β/Њ
104.39(1)
90
4795.6(8)
1.855
4
2584
98.73(1)
90
4871.7(8)
2.172
16
2976
90
90
γ/Њ
U/Å3
1349.9(2)
3.170
8 (monomers)
1152
Dc/g cmϪ3
Z
F(000)
µ(Mo-Kα)/cmϪ1
64.6
126.3
225.20
Data collection
T/ЊC
Scan mode
Ϫ74
ω
Ϫ74
ω
Ϫ74
ω
hkl Ranges
Ϫ16 to 16, Ϫ18 to 0, 0–30
0.64
9576
9364 (0.0187)
9358
ψ Scans
0.54, 0.99
0–25, 0–16, Ϫ27 to 26
0.64
6016
5843 (0.0223)
5783
ψ Scans
0–14, Ϫ13 to 0, 0–14
0.64
1464
1463
1441
ψ Scans
0.72, 0.99
Sin(θ/λ)max/ÅϪ1
Measured reflections
Unique reflections (Rint
)
Reflections used for refinement
Absorption correction
Tmin; Tmax
0.54, 0.99
Refinement
Refined parameters
H atoms (found, calculated)
Final R values [I > 2σ(I)]
R1a
580
0, 42
181
0, 30
55
0, 6
0.0292
0.0617
0.0311
0.0571
0.0459
0.1075
wR2b
(Shift/error)max
<0.001
0.82, Ϫ0.73
<0.001
0.88, Ϫ1.22
<0.001
1.86, Ϫ2.73
ρ(maximum, minimum)/e ÅϪ3
2
½
2
a R = Σ( |Fo| Ϫ |Fc| )/Σ|Fo|. b wR2 = [Σw(Fo2 Ϫ Fc2)2/Σw(Fo )2] ; w = 1/[σ2(Fo ) ϩ (aP)2 ϩ bP]; P = (Fo2 ϩ 2Fc2)/3; a = 0.0248 (1), 0.0168 (5), 0.0459 (8);
b = 10.6 (1), 24.9 (5), 23.17 (8). c The residual electron densities are located around the gold atoms.
Me2P(S)SAu{P(o-Tol)3} 7. The synthesis was analogous to
that of 5 with Me2P(S)SNa (35 mg, 0.24 mmol) and {(o-Tol)3-
P}AuCl (127 mg, 0.24 mmol) to give 147 mg (96%) of 7. Crys-
tals could be obtained from dichloromethane solution by layer-
ing with pentane, m.p. 178 ЊC (decomp.) (Found: C, 44.21; H,
4.40; S, 9.37. C23H27AuP2S2 requires C, 44.09; H, 4.34; S,
and Patterson methods (5 and 8), and refined by full-matrix
least-squares calculations against F 2.35 The thermal motion of
all non-hydrogen atoms was treated anisotropically except for
the highly disordered BF4Ϫ anion of compound 1. The disorder
was resolved into 12 split fluorine positions (8 F positions with
site occupation factor of 0.25, 4 F positions with site occu-
pation factor of 0.5) with idealized geometry. All hydrogen
atoms were calculated in idealized positions and their isotropic
thermal parameters were tied to that of the adjacent carbon
atom by a factor of 1.5. Details of crystal data, data collection
and structure refinement are summarized in Table 1. Important
interatomic distances and angles are given in the corresponding
figure captions.
1
10.23%). NMR (CDCl3): H, δ 6.93–7.76 (m, 12 H, aryl H),
2.32 (s, 9 H, C6H4Me), 2.12 [d, J(HP) 13 Hz, 6 H, P(S)Me2];
31P-{1H}, δ 57.5 [s, 1 P, Me2P(S)], 17.1 [s, 1 P, (o-Tol)3PAu]. FAB
mass spectrum: m/z 626 (50%, [M]ϩ).
[Me2P(S)SAu]2 8. The compound was prepared from
Me2P(S)SNa (50 mg, 0.34 mmol) and (Me2S)AuCl (99 mg, 0.34
mmol) in tetrahydrofuran (20 ml), as described for 5, to give 58
mg (53%) of 8. Crystals suitable for X-ray studies could be
obtained from dichloromethane solution by layering with pen-
tane, m.p. 183 ЊC (decomp.) (Found: C, 7.57; H, 2.04; S, 19.80.
C2H6AuPS2 requires C, 7.46; H, 1.88; S, 19.91%). NMR
(CD2Cl2): 1H (room temperature) δ 2.26 [d, J(HP) 10]; (Ϫ90 ЊC)
δ 2.22 [d, J(HP) 10 Hz]; 31P-{1H}, δ 64.7 (s); 13C-{1H}, δ 29.6 [d,
J(CP) 55 Hz]. FAB mass spectrum: m/z 644 (3.7%, [M]ϩ).
CCDC reference number 186/759.
Acknowledgements
This work was supported by Deutsche Forschungsgemein-
schaft, by Fonds der Chemischen Industrie, and, through the
donation of chemicals, by Degussa AG and Heraeus GmbH.
The authors are grateful to Mr. J. Riede for establishing the
X-ray data sets and Mr. D. Schoen for his experimental support.
Crystal structure determinations
Suitable single crystals of compounds 1, 5 and 8 were sealed in
glass capillaries and used for measurement of precise cell con-
stants and intensity data collection. During data collection,
three standard reflections were measured periodically as a gen-
eral check of crystal and instrument stability. No significant
changes were observed for any of the compounds. Diffraction
intensities were corrected for Lorentz, polarization and absorp-
tion effects. The structures were solved by direct methods (1)
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