Coordination modes of diphenylphosphinothioformamide in its neutral and deprotonated forms at gold(I)

Article abstract of DOI:10.1039/b211865c

The reaction of the polydentate ligand Ph₂PC(S)N(H)Me with various Au(I) substrates and in different molar ratios leads to complexes with different geometries around the gold center, such as linear mononuclear complexes, [AuCl{Ph₂PC(S)N(H)Me}] (1), [Au(C₆F ₅){Ph₂PC(S)N(H)Me}] (2) or [Au{Ph₂PC(S)N(H)Me} ₂]ClO₄ (4), linear polynuclear derivatives, [Au ₂(C₆F₅)₂{Ph₂PC(S)N(H)Me}] ₂ (3) and [Au{Ph₂PC(SAuCl)N(H)Me}₂]ClO ₄ (6), or the three-coordinate complex [Au{Ph₂PC(S)N(H)Me} ₃]ClO₄ (5). Treatment of 1 with Tl(acac) produces the deprotonated derivative [Au{Ph₂PC(S)NMe}]₂ (7), which can further react with other gold(I) starting materials leading to the synthesis of [Au₂{Ph₂PC(S)N(AuX)Me}₂] (X = Cl (8) and C ₆F₅ (9)). The crystal structures of complexes 1, 3, 5 and 7 have been determined by X-ray diffraction studies. The Royal Society of Chemistry 2003.

Full text of DOI:10.1039/b211865c

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Coordination modes of diphenylphosphinothioformamide in its
neutral and deprotonated forms at gold(I)
Olga Crespo,a Eduardo J. Fernández,b Peter G. Jones,c Antonio Laguna,*a
José M. López-de-Luzuriaga,b Miguel Monge,b M. Elena Olmosb and Javier Pérezb
a Departamento de Química Inorgánica, Instituto de Ciencia de Materiales de Aragón,
Universidad de Zaragoza-CSIC, 50009 Zaragoza, Spain. E-mail: alaguna@posta.unizar.es.
b Departamento de Química, Universidad de la Rioja, Grupo de Síntesis Química de La Rioja,
UA-CSIC, Complejo Científico Tecnológico, 26001 Logroño, Spain
c Institut für Anorganische und Analytische Chemie der Technischen Universität, Postfach 3329,
D-38023 Braunschweig, Germany
Received 29th November 2002, Accepted 22nd January 2003
First published as an Advance Article on the web 11th February 2003
The reaction of the polydentate ligand Ph2PC(S)N(H)Me with various Au() substrates and in different molar
ratios leads to complexes with different geometries around the gold center, such as linear mononuclear complexes,
[AuCl{Ph2PC(S)N(H)Me}] (1), [Au(C6F5){Ph2PC(S)N(H)Me}] (2) or [Au{Ph2PC(S)N(H)Me}2]ClO4 (4), linear
polynuclear derivatives, [Au2(C6F5)2{Ph2PC(S)N(H)Me}]2 (3) and [Au{Ph2PC(SAuCl)N(H)Me}2]ClO4 (6),
or the three-coordinate complex [Au{Ph2PC(S)N(H)Me}3]ClO4 (5). Treatment of 1 with Tl(acac) produces the
deprotonated derivative [Au{Ph2PC(S)NMe}]2 (7), which can further react with other gold() starting materials
leading to the synthesis of [Au2{Ph2PC(S)N(AuX)Me}2] (X = Cl (8) and C6F5 (9)). The crystal structures of
complexes 1, 3, 5 and 7 have been determined by X-ray diffraction studies.
In this paper we report the synthesis of new mono- and poly-
Introduction
nuclear gold() complexes with the ligand Ph2PC(S)N(H)Me
and its corresponding anion [Ph2PC(S)NMe]Ϫ as a multi/
mixed-functional donor for gold(). Tiekink et al.12,13 have
summarized the coordination capabilities of this type of lig-
ands to different organometallic or metallic substrates, but a
systematic study of the coordination capabilities of this ligand
without varying metal centers has not been reported to date. In
this paper we present two- or three-coordinated mononuclear
complexes, dinuclear compounds, and also one tetranuclear
complex formed via gold()–gold() intermolecular interactions.
A common strategy in the synthesis of polynuclear complexes is
the use of ligands bearing various donor sites. In the case of
gold, the most favorable ligands are polyfunctional molecules
with P-, S-, or N-donor centers.1 The combination of different
donor atoms in the same ligand can offer a combination of
stability and reactivity; some such ligands have recently been
revealed as instrumental in the preparation of complexes that
can be used for a number of applications including chemo-
therapy, diagnosis, electron microscopy, catalysis and surface
technology.2–6
We have recently been able to isolate molecular and cationic
species in which phosphorus and sulfur atoms {(phenylthio-
methyl)diphenylphosphine (PPh2CH2SPh)}7–9 or phosphorus
and nitrogen atoms {3,4-bis(diphenylphosphinoamino)toluene
(3,4-(NHPPh2)2MeC6H3), 1,2-bis(diphenylphosphinoamino)-
benzene (1,2-(NHPPh2)2C6H4)10 or 2-(diphenylphosphino)-
aniline (PPh2C6H4NH2)}11 act as nucleation centers giving rise
to homo- or hetero-polynuclear species, associated with the dif-
ferent coordination abilities of the donor centers. As a part of
our own ongoing investigations we wished to use a functional-
ised phosphine bearing nitrogen- and sulfur-donor substituents
in addition to the phosphorus atom. Our choice fell on the
diphenylphosphinothioformamide ligand Ph2PC(S)N(H)Me
and its deprotonated derivative [Ph2PC(S)NMe]Ϫ (See Chart 1)
since they display some interesting features. First, these poten-
tially polydentate ligands can promote selective heteroatom
(P, S and/or N) coordination to gold() centers and, thus, allow the
synthesis of different mono- and polynuclear gold() complexes
in which Au()–Au() interactions or hydrogen bonds would
play an important role. Second, the flexibility characteristics12
of these ligands allow very different structural arrangements,
even with the same donor centers bonded to the same metal.
Results and discussion
The ligand diphenylphosphinothioformamide (Ph2PC(S)-
N(H)Me) is readily prepared from diphenylphosphine and
methyl isothiocyanate in equimolecular amounts according to
the literature procedure.14 It reacts with gold() species such as
[AuCl(tht)] or [Au(C6F5)(tht)] (tht = tetrahydrothiophene) in a
1 : 1 molar ratio, leading to the mononuclear derivatives
[AuCl{Ph2PC(S)N(H)Me}] (1) or [Au(C6F5){Ph2PC(S)N(H)-
Me}] (2), respectively, as illustrated in Scheme 1, by displace-
ment of the weakly coordinated tht ligand. The elemental
analysis and physical and spectroscopic properties of these
products are in accordance with the proposed stoichiometry.
Their molar conductivities in acetone solutions (ΛM = 4 (1),
5 (2) ΩϪ1 cm2 molϪ1) rule out an ionic formulation and, fur-
thermore, their IR spectra show, among others, bands at 326 (1)
and at 1503, 951 and 791 cmϪ1 (2), which are assigned to the
15
16,17
1
Au–Cl and Au–C6F5
units, respectively. In the H NMR
spectra the aminic protons appear at 9.4 (1) and at 8.5 (2) ppm
and in their 31P{1H} NMR spectra a single resonance appears,
which is shifted more than 41 ppm downfield compared to that
of the ligand, indicative of Au–P coordination.
A curious and exclusive characteristic of complex 2 is the
progressive decoloration of the initially yellow chloroform solu-
tions of this complex used in the NMR experiments, which
begins after a few minutes and is complete in approximately one
hour. In its 31P{1H} NMR spectrum a new signal at 50.7 ppm
appears with increasing relative intensity, as the decoloration
progresses. In the 1H NMR spectrum the signal corresponding
Chart 1
D a l t o n T r a n s . , 2 0 0 3 , 1 0 7 6 – 1 0 8 2
T h i s j o u r n a l i s © T h e R o y a l S o c i e t y o f C h e m i s t r y 2 0 0 3
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Scheme 1
Table 1 Bond lengths [Å] and angles [Њ] for compound 1
to the aminic proton of the starting material decreases in
intensity until it disappears and, in addition, in its 19F NMR
spectrum the signals corresponding to the pentafluorophenyl
rings bonded to gold() also disappear. The chemical shift of
50.7 ppm in the 31P{1H} NMR spectrum is similar to that
obtained for the previously reported dimeric complex [Au{Ph2-
PC(S)NMe}]2.13 These facts seem to be in accordance with a
process of simultaneous deprotonation of the aminic protons
of two [Au(C6F5)(Ph2PC(S)N(H)Me)] units by the pentafluoro-
phenyl rings of the adjacent units; whereby these act as Lewis
bases producing pentafluorobenzene. An example of the depro-
tonating ability of the pentafluorophenyl group has previously
been described18 in the gold complex [Au(C6F5)PhP(O)H] and
is in good agreement with our results.
Notwithstanding, the crystal structure of complex 1 has been
unequivocally determined by X-ray diffraction studies. The
geometry at the gold atom (Fig. 1) is linear (P–Au–Cl
177.13(3)Њ, see Table 1). The Au–P and Au–Cl bond distances
(2.2254(7), 2.2866(8) Å respectively) are very similar to those
found in [AuCl(PPh3)]19 or in the dinuclear [Au2Cl2(µ-dppf )]
Au–P
2.2254(7)
2.2866(8)
1.809(3)
1.814(3)
P–C(1)
S–C(1)
N–C(1)
N–C(2)
1.844(3)
1.658(3)
1.318(3)
1.461(4)
Au–Cl
P–C(11)
P–C(21)
P–Au–Cl
177.13(3)
106.55(12)
102.65(12)
107.36(12)
115.75(8)
115.62(9)
C(1)–P–Au
C(1)–N–C(2)
N–C(1)–S
N–C(1)–P
S–C(1)–P
107.87(8)
123.4(3)
125.5(2)
118.5(2)
115.92(14)
C(11)–P–C(21)
C(11)–P–C(1)
C(21)–P–C(1)
C(11)–P–Au
C(21)–P–Au
(dppf = 1,1Ј-bis(diphenylphosphino)ferrocene).20,21 Molecules
adjacent by translation parallel to the y axis are connected by
rather long (2.64 Å) hydrogen bonds N–H ؒ ؒ ؒ Cl. Further
contacts C–H ؒ ؒ ؒ Cl and C–H ؒ ؒ ؒ Au, 2.94 and 3.18 Å
respectively, might be considered as weak hydrogen bonds
(Table 2).
The presence of various donor centers in these mononuclear
species allows the synthesis of polynuclear derivatives. For
instance, the reaction of the ligand Ph2PC(S)N(H)Me with two
equivalents of the mononuclear gold complex [Au(C6F5)(tht)]
or, starting from the mononuclear derivative [Au(C6F5)-
{Ph2PC(S)N(H)Me}] (2), the reaction with one more equiv-
alent of [Au(C6F5)(tht)], gives rise to the tetranuclear species
[Au2(C6F5)2{Ph2PC(S)N(H)Me}]2 (3), as an air-stable yellow
solid. All the analytical data are in accordance with the pro-
posed stoichiometry, and the presence of 19F NMR signals
corresponding to two inequivalent pentafluorophenyl groups
confirms the presence of two types of magnetically different
Au(C6F5) units in the molecule. Its 31P{1H} NMR spectrum
also shows a displacement of the signal to low field with respect
to the free ligand, indicating the coordination of this nucleus to
one of these units (see Experimental). Nevertheless, the sulfur
or nitrogen atoms could be involved in the coordination to the
other Au(C6F5) fragment. Based on its infrared spectrum, it is
difficult to distinguish these two possibilities, since both the
ν(C᎐N) stretching mode and ν(C᎐S) appear at energies very
᎐
᎐
close to those observed in the free ligand, which would indicate
an electronic delocalization between these bonds.13,22 Neverthe-
less, previous work in gold chemistry with S,N-donor ligands
Fig. 1 Molecular structure of complex 1.
D a l t o n T r a n s . , 2 0 0 3 , 1 0 7 6 – 1 0 8 2
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Table 2 Hydrogen bond lengths [Å] and angles [Њ]
Compound 1a
D–H ؒ ؒ ؒ A
d(D–H)
d(H ؒ ؒ ؒ A)
d(D ؒ ؒ ؒ A)
<(DHA)
N–H(0) ؒ ؒ ؒ Cl#1
C(23)–H(23) ؒ ؒ ؒ Cl#2
C(26)–H(26) ؒ ؒ ؒ Au#3
0.88
0.95
0.95
2.60
2.94
3.18
3.294(3)
3.665(3)
3.944(3)
136.3
133.9
139.1
Compound 3b
D–H ؒ ؒ ؒ A
d(D–H)
d(H ؒ ؒ ؒ A)
d(D ؒ ؒ ؒ A)
<(DHA)
132.0
N(1)–H(1) ؒ ؒ ؒ F(12)#1
0.86
2.42
3.062(9)
a Symmetry transformations used to generate equivalent atoms: #1 x, y Ϫ 1, z; #2 Ϫx ϩ 1, Ϫy ϩ 1, Ϫz ϩ 1; #3 Ϫx, Ϫy ϩ 1, Ϫz ϩ 1.
b Symmetry transformations used to generate equivalent atoms: #1 Ϫ x, y ϩ 1/2, Ϫz ϩ 1/2.
Table 3 Selected bond lengths [Å] and angles [Њ] for complex 3
has shown that the sulfur atom is the preferred site for coordin-
ation to the gold center.23
Au(1)–C(1)
Au(2)–C(11)
Au(3)–C(21)
Au(4)–C(31)
Au(1)–Au(2)
Au(3)–Au(4)
C(41)–N(1)
N(1)–C(42)
P(1)–C(71)
C(51)–N(2)
N(2)–C(52)
P(2)–C(91)
2.068(8)
2.029(8)
2.041(8)
2.074(7)
3.1631(5)
3.0391(5)
1.314(10)
1.477(12)
1.804(9)
1.316(10)
1.455(11)
1.802(8)
Au(1)–P(1)
Au(2)–S(1)
Au(3)–S(2)
Au(4)–P(2)
Au(2)–Au(3)
S(1)–C(41)
C(41)–P(1)
P(1)–C(61)
S(2)–C(51)
C(51)–P(2)
P(2)–C(81)
2.273(2)
2.315(2)
2.316(2)
2.270(2)
3.2712(5)
1.679(8)
1.843(9)
1.801(8)
1.693(9)
1.840(9)
1.802(9)
The crystal structure of complex 3 has been determined by
X-ray diffraction analysis and confirms the phosphorus– and
sulfur–gold coordination. Crystals of 3 were obtained by slow
diffusion of hexane into a solution of the complex in dichloro-
methane. Compound 3 (Fig. 2) crystallizes forming tetranuclear
units formed by an intermolecular Au ؒ ؒ ؒ Au interaction of
3.2712(5)
Å (Table 3) between two [Au2(C6F5)2{PPh2-
C(S)N(H)Me}] units; intermetallic distances between adjacent
tetranuclear units are approximately 6 Å. This intermolecular
Au ؒ ؒ ؒ Au interaction is longer than those found in the related
13
complex [Au(Ph2PC(S)NPh)]2
(3.146(1) Å) or in other di-
C(1)–Au(1)–P(1)
C(21)–Au(3)–S(2)
Au(1)–Au(2)–Au(3) 161.06(1)
175.9(2)
175.1(2)
C(11)–Au(2)–S(1)
C(31)–Au(4)–P(2)
Au(4)–Au(3)–Au(2) 170.13(1)
174.8(2)
176.4(2)
nuclear bridged gold() complexes that display inter- and intra-
molecular metal–metal interactions24–27 (intermolecular
Au ؒ ؒ ؒ Au distances between 2.954(1) 24 and 3.171(3) Å 26) and
similar to that observed in the polymer [ClAu{Ph2P(CH2)8-
PPh2}AuCl]∞ 28 (3.264(2) Å). Both independent dinuclear units
of complex 3 also show intramolecular Au ؒ ؒ ؒ Au contacts of
3.0391(5) and 3.1631(5) Å, respectively. These distances are also
longer than those in the related complexes [Au(Ph2PC(S)-
P(1)–Au(1)–Au(2)
C(11)–Au(2)–Au(1)
C(11)–Au(2)–Au(3)
C(21)–Au(3)–Au(4)
C(21)–Au(3)–Au(2)
C(31)–Au(4)–Au(3)
C(41)–S(1)–Au(2)
N(1)–C(41)–P(1)
C(41)–N(1)–C(42)
N(2)–C(51)–S(2)
S(2)–C(51)–P(2)
76.97(6)
92.9(2)
105.5(2)
93.2(2)
87.7(2)
97.9(2)
108.5(3)
117.3(6)
122.8(7)
120.3(7)
120.5(5)
C(1)–Au(1)–Au(2)
S(1)–Au(2)–Au(1)
S(1)–Au(2)–Au(3)
S(2)–Au(3)–Au(4)
S(2)–Au(3)–Au(2)
P(2)–Au(4)–Au(3)
N(1)–C(41)–S(1)
S(1)–C(41)–P(1)
C(51)–S(2)–Au(3)
N(2)–C(51)–P(2)
C(51)–N(2)–C(52)
99.1(2)
88.35(6)
72.93(6)
91.13(6)
87.66(6)
79.33(6)
121.0(7)
121.7(5)
108.9(3)
119.2(7)
124.2(8)
13
13
NPh)]2 (2.9241(1) and 2.919(1) Å), [Au(cHex2PC(S)NPh)]2
7
(2.869(1) Å) or [Au(Ph2PCH2SPh)]2(CF3SO3)2 (2.9020(5) Å),
that are doubly coordinated by the P,S-donor ligands. The gold
atoms in complex 3 exhibit linear geometry at the gold centres
(C–Au–P angles of 175.9(2) and 176.4(2)Њ and C–Au–S angles
of 175.1(2) and 174.8(2)Њ) with typical Au–C distances between
2.029(8) and 2.074(7) Å. The Au–P distances, of 2.273(2) and
2.270(2) Å, are slightly longer than in complex 1 (2.2254(7) Å)
and compare well with those observed in [Au(Ph2PC(S)NPh)]2
13 (2.265(5) and 2.271(5) Å), [Au(cHex2PC(S)NPh)]2 13 (2.276(1)
7
than the Au–S distance in [Au(Ph2PCH2SPh)]2(CF3SO3)2
(2.3619(11) Å) and closer to those found in [Au(Ph2PC-
13
(S)NPh)]2 (from 2.306(5) to 2.318(3) Å) or in [Au(cHex2PC-
(S)NPh)]2 13 (2.306(1) Å). Complex 3 also shows an N–H ؒ ؒ ؒ F
hydrogen bond between adjacent tetranuclear units with an
H ؒ ؒ ؒ F distance of 2.42 Å (Table 2).
7
Å) or [Au(Ph2PCH2SPh)]2(CF3SO3)2 (2.2721(11) Å), while
the Au–S distances in 3 (2.315(2) and 2.316(2) Å) are shorter
Cationic complexes can be synthesized in similar ways using
the complex [Au(tht)2]ClO4 as gold precursor. Thus, its reac-
tions with diphenylphosphinothioformamide in a 1 : 2 or 1 : 3
molar ratio give rise to the mononuclear derivatives [Au-
{Ph2PC(S)N(H)Me}2]ClO4 (4) or [Au{Ph2PC(S)N(H)Me}3]-
ClO4 (5), respectively, in high yield, by displacement of both
tetrahydrothiophene ligands. The analytical data are in accord-
ance with the proposed formulation. For both complexes, the
molar conductivity in dilute acetone solutions (see Experi-
mental), and also the presence in the infrared spectra of bands
due to the ionic perchlorate at around 1100 (br,vs) and 620 (m)
cmϪ1 29
are in accordance with an ionic formulation. Also, in
,
both cases, the presence of only one resonance in their 31P{1H}
NMR spectra and the downfield shift, more than 40 ppm com-
pared with the starting material, is indicative of the equivalence
of all the phosphorus atoms in each complex, and also of the
coordination of the ligands through the phosphorus centers.
In the case of complex 5, the three-coordination around the
gold() center is confirmed in solid state by the X-ray diffraction
analysis and, significantly, the absence of any other phosphorus
resonance in the spectrum of this complex suggests that the
Fig. 2 Molecular structure of complex 3. Aromatic H atoms are
omitted for clarity.
D a l t o n T r a n s . , 2 0 0 3 , 1 0 7 6 – 1 0 8 2
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Table 4 Selected bond lengths [Å] and angles [Њ] for compound 5a
Table 5 Selected bond lengths [Å] and angles [Њ] for compound 7a
Au–P(1)
P–C(11)
P–C(21)
P–C(1)
2.3759(13)
1.814(5)
1.818(5)
1.860(5)
S–C(1)
N–C(1)
N–C(2)
1.645(5)
1.319(7)
1.452(7)
Au–P
Au–S#1
2.2685(16)
2.3276(17)
Au–Au#1
2.9104(6)
P–Au–S#1
170.52(6)
78.64(4)
93.74(4)
117.5(2)
114.59(19)
107.2(2)
C(1)–S–Au#1
C(1)–N–C(2)
N–C(1)–S
N–C(1)–P
S–C(1)–P
104.9(2)
118.7(6)
126.6(5)
115.6(5)
117.8(3)
P–Au–Au#1
S#1–Au–Au#1
C(11)–P–Au
C(21)–P–Au
C(1)–P–Au
P#1–Au–P
119.429(9)
104.7(2)
106.1(2)
101.7(3)
107.64(17)
120.43(17)
C(1)–P–Au
C(1)–N–C(2)
N–C(1)–S
N–C(1)–P
S–C(1)–P
115.02(17)
123.7(5)
124.7(4)
113.3(4)
122.0(3)
C(11)–P–C(21)
C(11)–P–C(1)
C(21)–P–C(1)
C(11)–P–Au
C(21)–P–Au
a Symmetry transformations used to generate equivalent atoms: #1 Ϫx
ϩ 1/2, Ϫy ϩ 1/2, z.
a Symmetry transformations used to generate equivalent atoms: #1:
Ϫy ϩ 1, x Ϫ y, z.
typical of 1 : 1 electrolytes. Also, its 31P{1H} NMR spectrum
displays one single resonance, which indicates that the equiv-
alence of both phosphorus centers in the starting material is not
affected for the new metal coordination.
Attempts to synthesize polynuclear molecules starting from
the three-coordinate complex 5 and gold() precursor com-
plexes bearing weakly coordinated ligands led to the dissoci-
ation of one of the ligands and to the isolation of a mixture
of products, in which we could identify the mononuclear
complex 4.
As has been observed for complex 2, the phosphinodithio-
formamide ligand Ph2PC(S)N(H)Me is reactive towards Lewis
bases, deprotonating the amide group and leading to a new
anionic ligand [Ph2PC(S)NMe]Ϫ in which the redistribution of
the electron density allows a new reactivity towards gold()
precursors.
Thus, the reaction between complex [AuCl{Ph2PC(S)N(H)-
Me}] (1) and Tl(acac) (acac = acetylacetonate) in equimolecular
amounts leads to the formation of [Au{Ph2PC(S)NMe}] units
in solution, accompanied by precipitation of TlCl and de-
protonation by the acetylacetonate ligand. These mononuclear
units self-associate giving the diauracyclic complex [Au{Ph2-
PC(S)NMe}]2 (7) (Scheme 2). This complex was already
described by Tiekink et al.13 and synthesized by a different
route. Its analytical and spectroscopic data are in accordance
with those already reported.
three-coordination remains also in solution. The molecule (Fig.
3) crystallizes in the trigonal system. The gold center lies on a
three-fold axis 0.13 Å out of the plane formed by the three
phosphorus atoms. The Au–P distance (2.3759(13) Å) (Table 4)
is very close to those found in [Au{Ph2P(C6H4)NH2}3]ClO4
(2.3688(12), 2.3738(12) Å).11 These values lie between those
found in [Au(PPh3)3]ClO4 (2.345–2.408 Å, three independent
determinations)30–32 or in other three-coordinated complexes of
the type [Au(P–P)P]ϩ in which P–P is a diphosphine and P a
monophosphine bonded to gold. In such cases the Au–P
(monodentate phosphine) distance (opposite to the narrow-
est angle) is shorter than the other two, some examples are
[Au{(PPh2)2C2B10H10}(PPh3)]ClO4 (2.318(1)–2.417(1) Å),33
[Au{(PPh2)2C2B9H10}(PPh3)] (2.2831(13)–2.3952(12) Å) or
[Au2{µ-dppp}{(PPh2)2C2B9H10}2] (2.288(3)–2.443(3) Å).34
The crystal structure of complex 7 has been elucidated by
X-ray diffraction analysis (Fig. 4). The molecule possesses
crystallographic two-fold symmetry. The gold centers display
distorted linear geometry (P–Au–S#1 170.52(6)Њ) (Table 5),
associated with the presence of intramolecular gold ؒ ؒ ؒ gold
contacts of 2.9014(6) Å. These interactions are shorter than
those found in 3. The Au–P (2.2685(13) Å) distance is shorter
than that found in 3, whereas the Au–S#1 (2.3276(17) Å) bond
distance is slightly shorter in 3 than in 7. Both the phosphorus
and sulfur donor heteroatoms are coordinated to gold()
centers, forming an eight-membered metallacyclic ring, while
the nitrogen atoms are in an exocyclic disposition that could
be appropriate for the coordination of further metal centers,
thus, enhancing the nuclearity of the starting complex. Accord-
ingly, reaction of complex [Au{Ph2PC(S)NMe}]2 (7) with two
Fig. 3 Structure of the cation of complex 5. H atoms omitted for
clarity.
In the same way as before, the presence of poly-donor substi-
tuents permits further coordination of gold centers. Thus, the
reaction of [Au{Ph2PC(S)N(H)Me}2]ClO4 (4) and two equiv-
alents of the precursor [AuCl(tht)] leads to the synthesis of the
pale-yellow complex [Au{Ph2PC(SAuCl)N(H)Me}2]ClO4 (6)
(see Scheme 1). Its infrared spectrum, in addition to the bands
from the thioformamide ligand and the ionic perchlorate, dis-
plays a broad absorption at 327 cmϪ1. This can be assigned to
the stretching ν(Au–Cl) and ν(Au–S) vibration modes, which
appear at similar energies; this is indicative of the coordination
of the new Au–Cl units to the starting material through the
sulfur centers. Its ionic nature is also confirmed by the conduct-
ivity measurement in acetone solution (126 ΩϪ1 cm2 molϪ1),
Fig. 4 Molecular structure of complex 7.
D a l t o n T r a n s . , 2 0 0 3 , 1 0 7 6 – 1 0 8 2
1079

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Scheme 2
equivalents of [AuX(tht)] (X = Cl or C6F5) leads to the form-
ation of derivatives [Au2{Ph2PC(S)N(AuX)Me}2] (X = Cl (8)
and C6F5 (9)) by displacement of the weakly coordinated tetra-
hydrothiophene ligand and coordination of the [AuX] frag-
ments to the nitrogen atoms of complex 7 (See Scheme 2). The
analytical data for both complexes are in accordance with the
proposed formulation. The infrared spectrum for each complex
[Au(C6F5)(Ph2PC(S)N(H)Me)] (2). To a dichloromethane
solution (20 mL) of [Au(C6F5)(tht)] (0.2 g, 0.44 mmol) was
added Ph2PC(S)N(H)Me (0.115 g, 0.44 mmol) and the mixture
was stirred for one hour. After evaporation of the solvent to ca.
5 mL, addition of n-hexane (20 mL) gave complex 2 as a yellow
solid. Yield: 77%. Mass spectrum: [2M Ϫ C6F5]ϩ at m/z = 1080
(100%). Anal. Calcd. for: C20H14AuF5NPS (2): C, 38.55; H,
2.25; N, 2.25; S, 5.15. Found: C, 38.55; H, 2.40; N, 2.45; S,
4.75%. 31P{1H} NMR (CDCl3) δ: 56.0(s). 19F NMR (CDCl3)
δ: Ϫ116.33 [m, 2F, o-F], Ϫ156.66 [t, 1F, p-F, 3J(Fp–Fm) 19.9 Hz],
Ϫ162.09 [m, 2F, m-F]. 1H NMR (CDCl3) δ: 4.34 [d, CH3,
J(H–P) 7.4 Hz], 7.70–7.25 [m, aromatic protons], 8.50 [m,
show common ν(C᎐N) vibrations at 1602 (8) and 1592 cmϪ1 (9),
᎐
respectively, appearing at 1561 cmϪ1 for 7.13 Besides, complex 8
displays a vibration at 328 cmϪ1 corresponding to the ν(Au–Cl)
vibration, while complex 9 shows the ν(Au()–C6F5) pattern at
795, 955 and 1504 cmϪ1. In both cases these new vibrations arise
from the coordinated [AuX] fragments. The 31P{1H} NMR
spectra of these complexes show one singlet in each case at 48.0
(8) and 48.0 ppm (9). This chemical shifts are not very different
from that of the starting complex 7 (50.7 ppm), which would
indicate a similar coordination behavior for the phosphorus
centers.
N–H]. ΛM = 5.5 ΩϪ1 cm2 molϪ1
.
[Au2(C6F5)2(Ph2PC(S)N(H)Me)] (3). Method 1. To a solution
(20 mL) of [Au(C6F5)(tht)] (0.4 g, 0.88 mmol) in 20 mL
of dichloromethane was added Ph2PC(S)N(H)Me (0.115 g,
0.44 mmol) and after one hour of stirring the solvent was
evaporated to ca. 5 mL. Addition of n-hexane (20 mL) led to
precipitation of complex 3 as a pale-yellow solid. Yield:
72%. Method 2. To a dichloromethane solution (20 mL) of
[Au(C6F5)(tht)] (0.2 g, 0.44 mmol) was added [Au(C6F5)-
(Ph2PC(S)N(H)Me)] (2) (0.274 g, 0.44 mmol) and the mixture
was stirred for one hour. Evaporation of the solvent in a vac-
uum to ca. 5 mL and addition of n-hexane (20 mL) gave 3 as a
pale-yellow solid. Yield: 65%.
Experimental
General
Caution! Perchlorate salts may be explosive. The compounds
36
Ph2PC(S)N(H)Me,14 [Au(tht)2]ClO4,35 [AuCl(tht)]
[Au(C6F5)(tht)] 37 were prepared by literature methods.
and
Mass spectrum: [M Ϫ C6F5] at m/z = 820 (10%). Anal. Calcd.
for: C26H14Au2F10NPS (3): C, 31.65; H, 1.45; N, 1.40; S, 3.25.
Found: C, 31.5; H, 1.30; N, 1.45; S, 3.2%. 31P{1H} NMR
((CD3)2CO) δ: 60.0(s). 19F NMR ((CD3)2CO) δ: Ϫ114.53 [m, 2F,
o-F], Ϫ115.23 [m, 2F, o-F], Ϫ160.49 [t, 1F, p-F, 3J(Fp–Fm)
20.0 Hz] Ϫ161.84 [t, 1F, p-F, 3J(Fp–Fm) 20.0 Hz], Ϫ163.84
[m, 2F, m-F], Ϫ164.30 [m, 2F, m-F]. 1H NMR ((CD3)2CO)
δ: 3.55 [s, CH3], 7.96–7.71 [m, aromatic protons], 9.5 [m, N–H].
Instrumentation
Infrared spectra were recorded in the 4000–200 cmϪ1 range on a
Perkin-Elmer FT-IR Spectrum 1000 spectrophotometer, using
Nujol mulls between polyethylene sheets. C, H, N, S analysis
were carried out with a C.E. Instrument EA-1110 CHNS-O
microanalyser. Mass spectra were recorded on a HP-5989B
Mass Spectrometer API-Electrospray with interface 59987A.
1H, 19F and 31P{1H} NMR spectra were recorded on a Bruker
ARX 300 in (CD3)2CO or CDCl3 solutions. Chemical shifts are
quoted relative to SiMe4 (1H external), CFCl3 (19F external) and
H3PO4 (85%) (31P, external).
ΛM = 5 ΩϪ1 cm2 molϪ1
.
[Au(Ph2PC(S)N(H)Me)2]ClO4 (4). To a solution of [Au-
(tht)2]ClO4 (0.5 g, 1.00 mmol) was added Ph2PC(S)N(H)Me
(0.548 g, 2.1 mmol) in 20 mL of dichloromethane and the solu-
tion was stirred for one hour. Evaporation of the solvent to ca.
5 mL and further addition of diethyl ether (20 mL) led to the
precipitation of complex 4 as a yellow solid. Yield: 93%. Mass
spectrum: [M]ϩ at m/z = 715 (100%). Anal. Calcd. for:
C28H28AuClN2O4P2S2 (4): C, 41.25; H, 3.45; N, 3.45; S, 7.85.
Found: C, 41.35; H, 3.70; N, 3.90; S, 7.25%. 31P{1H} NMR
Synthesis
[AuCl(Ph2PC(S)N(H)Me)] (1). To a dichloromethane solu-
tion (20 mL) of [AuCl(tht)] (0.1 g, 0.3 mmol) was added
Ph2PC(S)N(H)Me (0.08 g, 0.3 mmol) and after one hour of
stirring the solvent was evaporated to ca. 5 mL. Addition of
n-hexane (20 mL) led to precipitation of complex 1 as a pale-
yellow solid. Yield: 83%. Mass spectrum: [M Ϫ Cl]ϩ at m/z =
456 (100%). Anal. Calcd. for: C14H14AuClNPS (1): C, 34.20;
H, 2.85; N, 2.85; S, 6.5. Found: C, 33.65; H, 2.45; N, 2.65; S,
1
(CDCl3) δ: 54.2(s). H NMR (CDCl3) δ: 4.16 [d, CH3, J(H–P)
6.2 Hz], 7.71–7.00 [m, aromatic protons], 9.25 [m, N–H].
ΛM = 117.4 ΩϪ1 cm2 molϪ1
.
6.25%. 31P{1H} NMR (CDCl3) δ: 55.5 (s). H NMR (CDCl3)
1
δ: 3.99 [m, CH3], 7.62–7.19 [m, aromatic protons], 9.44 [m,
[Au(Ph2PC(S)N(H)Me)3]ClO4 (5). To a dichloromethane
solution (20 mL) of [Au(tht)2]ClO4 (0.075 g, 0.16 mmol) was
N–H]. ΛM = 4.4 ΩϪ1 cm2 molϪ1
.
D a l t o n T r a n s . , 2 0 0 3 , 1 0 7 6 – 1 0 8 2
1080

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Table 6 Details of data collection and structure refinement for complexes 1, 3, 5 and 7
Compound
1
3
5
7
Formula
M
Crystal system
Space group
C14H14AuClNPS
491.71
Monoclinic
P21/c
C52H28Au4F20N2P2S2
1974.69
Monoclinic
P21/c
C42H42AuClN3OP3S3
1074.29
Trigonal
P(Ϫ3)
C28H26Au2N2P2S2
910.50
Orthorhombic
Pccn
a/Å
b/Å
c/Å
α/Њ
9.3007(9)
9.0894(8)
18.4826(18)
90
16.8870(2)
12.6690(2)
25.0874(3)
90
14.0697(9)
14.0697(9)
14.7342(11)
90
23.576(3)
7.0362(10)
16.6857(18)
90
β/Њ
98.385(3)
90
1545.8(3)
4
9.913
12477
4494
4494
0.0410
0.0219
0.0432
92.223(1)
90
5363.20(12)
4
11.155
56611
12730
11295
0.1010
0.0469
90
120
2526.0(3)
2
3.223
4944
2960
2960
90
90
2768.0(6)
4
10.876
4112
2440
2440
0.0284
0.0281
0.0652
γ/Њ
U/Å3
Z
µ(Mo-Kα)/mmϪ1
No. of reflections measured
No. of unique reflections
No. of reflections used
Rint
0.0230
0.0318
0.0901
Ra(F > 4σ(F))
wRb(F 2, all refl.)
0.0957
2
2
a R (F) = Σ || Fo | Ϫ | Fc ||/Σ | Fo |. b wR (F 2) = [Σ {w(Fo2 Ϫ Fc2)2}/Σ {w(Fo )2}]0.5; wϪ1 = σ2(Fo ) ϩ (aP)2 ϩ bP, where P = [Fo2 ϩ 2Fc2]/3 and a and b are
constants adjusted by the program.
added Ph2PC(S)N(H)Me (0.123 g, 0.48 mmol) and after one
hour of stirring the solvent was evaporated to ca. 5 mL. Addi-
tion of diethyl ether (20 mL) gave to the precipitation of com-
plex 5 as a yellow solid. Yield: 76%. Mass spectrum: [M]ϩ at m/z
= 974 (1%). Anal. Calcd. for: C42H42AuClN3O4P3S3 (5): C,
46.95; H, 3.95; N, 3.90; S, 8.95. Found: C, 46.50; H, 4.35; N,
ca. 5 mL. Addition of diethyl ether (20 mL) gave complex 9 as a
yellow solid. Yield: 40%. Mass spectrum: [M Ϫ AuC6F5]ϩ at m/z
= 1275 (15%). Anal. Calcd. for: C40H26Au4F10N2P2S2 (9): C,
29.30; H, 1.60; N, 1.70; S, 3.90. Found: C, 29.20; H, 2.05; N,
1.80; S, 4.20%. 31P{1H} NMR (CDCl3) δ: 48.0(s). 19F NMR
(CDCl3) δ: Ϫ115.10 [m, 4F, Ϫ159.60 [m, 2F, p-F], Ϫ163.20
1
1
3.75; S, 8.45%. 31P{1H} NMR (CDCl3) δ: 53.1(s). H NMR
[t, 4F, m-F]. H NMR (CDCl3) δ: 3.75 [m, CH3], 7.70–7.20
(CDCl3) δ: 3.83 [d, CH3, J(H–P) 6.5 Hz], 7.72–7.03 [m, aromatic
[m, aromatic protons].
protons], 9.35 [m, N–H]. ΛM = 114.2 ΩϪ1 cm2 molϪ1
.
Crystal structure determinations
[Au(Ph2PC(S)N(H)Me)2{AuCl}2]ClO4 (6). To a solution of
[Au(Ph2PC(S)N(H)Me)2]ClO4 (4) (0.08 g, 0.1 mmol) in 20 mL
of dichloromethane was added [AuCl(tht)] (0.063 g, 0.2 mmol)
and the mixture was stirred for one hour. Evaporation of the
solvent to 5 mL and addition of diethyl ether (20 mL) led to
precipitation of complex 6 as a yellow solid. Yield: 83%. Mass
spectrum: [M]ϩ at m/z = 1179 (40%). Anal. Calcd. for:
C28H28Au3Cl3N2O4P2S2 (6): C, 26.30; H, 2.20; N, 2.15; S, 5.01.
Found: C, 25.90; H, 2.55; N, 2.15; S, 5.15%. 31P{1H} NMR
The crystals were mounted in inert oil on a glass fibre and
transferred to the cold gas stream of a Bruker SMART 1000-
CCD (1), Siemens P4 (5, 7) and a Nonius Kappa CCD (3)
diffractometer. Data were collected using monochromated Mo
Kα radiation (λ 0.71073 Å). Absorption correction were based
on ψ-scans (5, 7) or multiple scans (Sadabs (1), Scalepack (3)).
The structures were refined on F 2 using the program SHELXL-
97.38 All non-hydrogen atoms were refined anisotropically.
H atoms were included using a riding model or rigid methyl
groups. Special features of refinement: restraints to light atom
U value components and to local ring symmetry were employed
to improve stability of refinement. Further crystallographic
details are given in Table 6. Compound 5: Ill-defined residual
electron density close to the threefold axis may be caused by
disordered solvent (possibly petrol ether components). The
largest such peak was arbitrarily refined as an isotropic C atom.
Values for M, density, etc., do not include any solvent.
1
(CDCl3) δ: 58.2(s). H NMR (CDCl3) δ: 5.58 [m, CH3], 8.10–
7.52 [m, aromatic protons], 10.59 [m, N–H]. ΛM = 125.6 ΩϪ1 cm2
molϪ1
.
[Au2{Ph2PC(S)NMe}2] (7). To a dichloromethane solution
(20 mL) of [AuCl(Ph2PC(S)N(H)Me)] (1) (0.100 g, 0.2 mmol)
was added [Tl(acac)] (0.062 g, 0.2 mmol) and after four hours
of stirring the TlCl precipitate was filtered off. Then the solvent
was evaporated to ca. 5 mL. Addition of n-hexane (20 mL) led
to precipitation of complex 7 as a pale-yellow solid. Yield: 56%.
CCDC reference numbers 200117–200119 & 200468.
See http://www.rsc.org/suppdata/dt/b2/b211865c/ for crystal-
lographic data in CIF or other electronic format.
[Au2{Ph2PC(S)N(AuCl)Me}2] (8). To a dichloromethane solu-
tion (20 mL) of [Au(Ph2PC(S)NMe)]2 (7) (0.075 g, 0.08 mmol)
was added [AuCl(tht)] (0.053 g, 0.16 mmol) and the solution
was allowed to stir for one hour. The solvent was evaporated to
ca. 5 mL. Addition of n-hexane (20 mL) led to precipitation of
complex 8 as a pale-yellow solid. Yield: 40%. Mass spectrum:
[M ϩ H]ϩ at m/z = 1376 (2%). Anal. Calcd. for: C28H26Au4-
Cl2N2P2S2 (8): C, 24.5; H, 1.90; N, 2.05; S, 4.80. Found: C,
24.75; H, 1.80; N, 2.05; S, 4.80%. 31P{1H} NMR (CDCl3)
Acknowledgements
We thank the D.G.I. (MYCT)/FEDER (BQU2001–2409), the
CAR (ANGI2001/28) and the Fonds der Chemischen Industrie
for financial support.
References
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δ: 48.0(s). H NMR (CDCl3) δ: 3.42 [m, CH3], 7.85–7.18 [m,
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D a l t o n T r a n s . , 2 0 0 3 , 1 0 7 6 – 1 0 8 2
1081

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