Tetrathiafulvalene-functionalized phosphine as a coordinating ligand. X-ray structures of (PPh2)4TTF and [(AuCl)4{(PPh2)4TTF}]

Article abstract of DOI:10.1039/b106310n

The phosphine (PPh₂)₄TTF (P4) (1) reacts with the gold(I) complexes [AuX(tht)] (X = Cl, C₆F₅; tht = tetrahydrothiophene) or [Au(Mes)(AsPh₃)] (Mes = 2,4,6-Me₃C₆H₂) to g

Full text of DOI:10.1039/b106310n

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Tetrathiafulvalene-functionalized phosphine as a coordinating
ligand. X-Ray structures of (PPh2)4TTF and
[(AuCl)4{(PPh2)4TTF}]
Elena Cerrada,a Carmelo Diaz,b M. Cristina Diaz,b Michael B. Hursthouse,c
Mariano Laguna*a and Mark E. Lightc
a Departamento de Química Inorgánica, Instituto de Ciencia de Materiales de Aragón,
Universidad de Zaragoza-C.S.I.C, E-50009 Zaragoza, Spain.
E-mail: mlaguna@posta.unizar.es
b Escuela Superior de Huesca, Carretera de Zaragoza, s/n, 22071 Huesca, Spain
c Department of Chemistry, University of Southampton, Highfield, Southampton,
UK SO17 1BJ
Received 16th July 2001, Accepted 14th December 2001
First published as an Advance Article on the web 11th February 2002
The phosphine (PPh2)4TTF (P4) (1) reacts with the gold() complexes [AuX(tht)] (X = Cl, C6F5;
tht = tetrahydrothiophene) or [Au(Mes)(AsPh3)] (Mes = 2,4,6-Me3C6H2) to give tetranuclear derivatives [(AuX)4P4]
(X = Cl, 2; C6F5, 3; Mes, 4). The analogous reaction starting with [Au(Trip)(AsPh3)] (Trip = 2,4,6-Pri3C6H2) provides
the dinuclear derivative [(AuTrip)2P4] (5). When the phosphine P4 reacts with [Cu(MeCN)4]PF6, AgCF3SO3 or
[Au(tht)2]CF3SO3 in a 2:1 molar ratio, complexes [M(P4)2]A (A = PF6, M = Cu, 6; A = CF3SO3, M = Ag, 7, Au, 8) are
obtained, or {[M2P4](CF3SO3)2}n (M = Ag, 9; Au, 10) when 1:1 molar ratios are used instead. Visible-ultraviolet and
electrochemical studies of the new complexes are reported. Two, reversible one-electron oxidations to the mono- and
di-cation occur in complexes 2–10 at more positive potentials than the two reversible oxidations exhibited by the free
P4 (1) ligand. The structures of 1 and 2 have been confirmed by X-ray analysis.
Introduction
During the past two decades there has been considerable
interest in the synthesis of materials with tunable conducting,
magnetic or optical properties. With reference to conduction,
one of the prerequisites for high conductivity is a partially filled
energy band. The stacking of planar (or near planar) π-donor
or -acceptor molecules improves the overlap of the π-systems,
developing the conduction band in this direction. In addition,
Fig. 1 Schematic representation of phosphine ligands based on
an increase in the dimensionality of these materials, which for
tetrathiafulvalene.
many systems has been achieved by interstack chalcogen–
chalcogen interactions, is known to stabilize the metallic
state by supressing the Peierls distorsion.1 The introduction of
characterization by X-ray analysis of one of these and of the P4
free ligand is also reported
heteroatoms such as S, Se and Te, with spatially extended pπ
orbitals, increases the π-overlap and results in wider bands.
Tetrathiafulvalene (TTF) and its derivatives2,3 represent the
most popular donor π-systems and have been extensively used
in conducting and superconducting radical cation salts, as well
as the donors obtained from the incorporation of Se and Te
atoms in the TTF skeleton.4,5
The use of chalcogen atoms in the structure of the donor
molecules has an important limitation involving a decrease
in their solubility. Considering this limitation, non-planar
molecules are expected to show higher solubility and their
three-dimensional character may favor solid-state interactions.
Working with this idea some different systems have been
studied, including non-planar tetrathiafulvalene-functionalized
systems with an increasing number of PPh2 groups6–11 (Fig. 1)
and molecules with two or more redox centers (TTF) linked
together in a non-planar arrangement.12–16
Results and discussion
(PPh2)4TTF (P4) was first prepared by Fourmigué et al.6 by
treatment of TTF with lithium diisopropylamide (LDA) and
the subsequent addition of PPh2Cl. Considering P4 as a tetra-
dentate phosphine, we have performed different reactions in
order to coordinate some different metallic centers, such as
Cu(), Ag() and Au().
The reaction of P4 (1) with gold() complexes with a labile
ligand such as tht (tetrahydrothiophene) or AsPh3 leads to the
coordination of the metallic center to four phosphorus atoms
of the P4 phosphines. Thus, starting with [AuX(tht)] (X = Cl,
C6F5) or [Au(Mes)(AsPh3)] (Mes = 2,4,6-Me3C6H2), complexes
with the general formula [(AuX)4P4] (X = Cl, 2; C6F5, 3; Mes, 4)
(process i, Scheme 1) are obtained, by simple displacement of
the labile ligand and posterior coordination of the metal to the
P atom.
In this paper we report the reactivity of the tetrathia-
fulvalene-funcionalized phosphine tetrakis(diphenylphosphine)-
tetrathiafulvalene, (PPh2)4TTF, (P4) with Cu(), Ag() and Au()
to give mono-, di- and tetra-nuclear derivatives. The solid-state
The IR spectra of complexes 2–4 do not show the character-
istic bands of the tht or AsPh3 ligands. Instead, we can identify
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J. Chem. Soc., Dalton Trans., 2002, 1104–1109
This journal is © The Royal Society of Chemistry 2002
DOI: 10.1039/b106310n

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Table 1 Selected bond lengths (Å) and angles (Њ) for 1
S(2)–C(14)
S(2)–C(15)
S(1)–C(13)
S(1)–C(14)
1.763(4)
1.764(4)
1.761(4)
1.763(4)
P(1)–C(13)
P(2)–C(15)
C(14)–C(14#)
1.832(4)
1.819(4)
1.340(8)
C(14)–S(2)–C(15)
C(13)–S(1)–C(14)
C(13)–C(15)–S(2)
C(13)–C(15)–P(2)
S(2)–C(15)–P(2)
C(15)–C(13)–S(1)
C(15)–C(13)–P(1)
S(1)–C(13)–P(1)
95.7(2)
95.4(2)
C(14#)–C(14)–S(1) 122.8(5)
S(2)–C(14)–S(1)
C(7)–P(1)–C(6)
C(7)–P(1)–C(13)
C(6)–P(1)–C(13)
C(15)–P(2)–C(22)
C(15)–P(2)–C(16)
C(22)–P(2)–C(16)
114.2(2)
102.5(2)
102.1(2)
100.6(2)
102.9(2)
101.7(2)
104.0(2)
116.8(3)
120.7(3)
122.4(3)
117.6(3)
123.1(3)
119.3(3)
C(14#)–C(14)–S(2) 123.1(5)
Symmetry transformations used to generate equivalent atoms: # Ϫx ϩ 1,
Ϫy ϩ 2, Ϫz.
Table 2 Selected bond lengths (Å) and angles (Њ) for 2
Au(1)–P(1)
Au(1)–Cl(1)
Au(1)–Au(2)
Au(2)–P(2)
Au(2)–Cl(2)
S(1)–C(3)
2.216(3)
2.278(3)
3.0081(8)
2.233(2)
2.288(3)
1.739(9)
1.773(9)
S(2)–C(1)
S(2)–C(2)
P(1)–C(3)
P(2)–C(2)
C(1)–C(1)i
C(2)–C(3)
1.752(8)
1.759(10)
1.825(9)
1.812(9)
1.310(19)
1.358(12)
Scheme 1
S(1)–C(1)
vibrations due to the P4 ligand as well as ν(Au–Cl) at 355 cmϪ1
in the case of 2, ν(Au–C6F5) at 956 and 793 cmϪ1 in 3 and
the bands corresponding to the mesityl group17 at 1655 and
843 cmϪ1 in complex 4.
P(1)–Au(1)–Cl(1)
P(1)–Au(1)–Au(2)
Cl(1)–Au(1)–Au(2) 104.35(8)
P(2)–Au(2)–Cl(2)
P(2)–Au(2)–Au(1)
Cl(2)–Au(2)–Au(1)
C(3)–S(1)–C(1)
C(1)–S(2)–C(2)
C(3)–P(1)–Au(1)
C(2)–P(2)–C(41)
174.41(10)
80.97(6)
C(2)–P(2)–Au(2)
C(1)i–C(1)–S(2)
C(1)i–C(1)–S(1)
S(2)–C(1)–S(1)
C(3)–C(2)–S(2)
C(3)–C(2)–P(2)
S(2)–C(2)–P(2)
C(2)–C(3)–S(1)
C(2)–C(3)–P(1)
S(1)–C(3)–P(1)
119.1(3)
124.4(9)
122.5(9)
113.1(5)
116.1(7)
128.9(8)
114.9(5)
117.6(7)
125.4(7)
116.9(5)
172.10(10)
90.11(6)
93.59(7)
95.8(4)
95.9(4)
114.5(3)
102.6(5)
The 1H NMR spectra show signals due to the phenyl groups
as multiplets, and in the case of 4 the signals corresponding to
the mesityl radical as singlets (protons from the ortho- and para-
methyl groups and protons in the meta position). The 31P{1H}
NMR spectra of complexes 2–4 display a singlet in all cases
downfield displaced (∆δ = 40–50 ppm) compared with the
value from the free ligand (Ϫ18.2 ppm).6 The LSIMSϩ mass
spectra exhibit in complexes 2 and 3 the molecular peaks
and additional peaks assignable to the fragmentation of the
molecule. In the case of 4 only fragmentation peaks are present.
Symmetry transformations used to generate equivalent atoms: Ϫx ϩ 1,
Ϫy ϩ 2, Ϫz.
Molecular structure of (PPh2)4TTFؒCHCl3 (1) and [(AuCl)4-
{(PPh2)4TTF}]ؒCH2Cl2 (2)
The crystalline structure of the dichloromethane solvate of
complex 2 has been studied by X-ray analysis, in addition to the
structure of the chloroform solvate of P4 (1) in order to com-
pare the geometries. Drawings of both are depicted in Fig. 2
Fig. 3 Solid state structure of 2. Displacement ellipsoids drawn at the
50% probability level. H atoms are omitted for clarity.
and 3. Selected bond distances and angles are provided in
Tables 1 and 2.
P4 (1) lies about an inversion centre and there is also a
0.5 occupancy of chloroform of solvation disordered about
another inversion centre. The TTFP4 core is nearly planar with
a dihedral angle between the planes (P1–C13–C15–P2) and
(C13–S1–C14–S2–C15) of 1.1Њ. The representative distances
C(14)–C(14#) = 1.340(8) Å, C(13)–C(15) = 1.353(6) Å and
S(1/2)–C(14) = 1.763(4) Å, are essentially unchanged relative to
Fig. 2 Solid state structure of 1. Displacement ellipsoids drawn at the
50% probability level. H atoms are omitted for clarity.
J. Chem. Soc., Dalton Trans., 2002, 1104–1109
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the bond lengths in TTF (1.35, 1.31 and 1.758 Å, respectively)18
or in the bis-phosphine TTF(Me)2(PPh2)2 [1.348(8), 1.344(6)
and 1.753(5) Å, respectively].6 The two phosphorus atoms
adopt the usual distorted tetrahedral geometry with C–P–C
angles being between 100.5 and 104.0Њ. The phosphorus–
carbon TTF distances, P(1)–C(13) = 1.832(4) Å and P(2)–C(15)
= 1.819(4) Å are similar to those reported for TTF(Me)2(PPh2)2
[1.821(6) and 1.819(5) Å, respectively].6 The molecules are
packed with no short contacts between them (the shortest dis-
tance is ca. 8.076 Å). The arrangement of this packing produces
channels as shown in Fig. 4, where the disordered chloroform
of crystallization resides (omitted from the figure for clarity).
Fig. 5 Projection of the unit cell of 2 along [010].
1
P atoms. In H NMR the signals from P4 and Trip keep a
P4:Trip ratio of 1:2, which is in accordance with the proposed
stoichiometry. In addition to these data, the mass spectrum
displays the molecular peak, although with a small intensity
[m/z(%) = 1741(5)], the corresponding fragmentation peak
([M Ϫ Trip]ϩ) and a higher m/z ratio, 1938 (6%), which can be
identified as [M ϩ Au]ϩ. The presence of the Trip radical, a
high space-demanding group, can be the explanation for the
isolation of the dinuclear compound instead of the tetranuclear
one.
The P4 phosphine can also act as a bidentate ligand in the
reaction with [Cu(MeCN)4]PF6, AgCF3SO3 or [Au(tht)2]-
CF3SO3 in a 2:1 molar ratio giving rise to [M(P4)2]A (A = PF6,
M = Cu, 6; A = CF3SO3, M = Ag, 7, Au, 8) derivatives with two
P4 units connected to the metallic center (process iv, Scheme 1).
The acetone solutions of complexes 6–8 show 1:1 electrolyte
behavior24 and the IR spectra display bands characteristic of an
ionic PF6 and triflate.25
Fig. 4 Projection of the unit cell of 1 along [001].
Compound 2 crystallizes with a dichloromethane solvent
molecule. The molecule again exhibits a crystallographic centre
of symmetry and consists of one P4 unit with four Au–Cl units
connected through the phosphorus atoms. In this case the
TTFP4 core is slightly bent with a dihedral angle between the
planes (P1–C3–C2–P2) and (C3–S1–C1–S2–C2) of 6Њ. The four
Au–Cl units are above and below the TTFP4 plane. The
coordination around the gold atoms deviates slightly from
linearity, which is typical for gold() derivatives [P(1)–Au(1)–
Cl(1) = 174.41(10)Њ and P(2)–Au(2)–Cl(2) = 172.10(10)Њ]. This is
a consequence of the presence of an intramolecular interaction
between the metallic centers Au(1) ؒ ؒ ؒ Au(2) of 3.0081(8) Å,
which is smaller than the sum of the van der Waals radii, illus-
trating the relativistic gold–gold contacts common for dinuclear
The 31P{1H} NMR spectra of complexes 6–8 reveal two
resonances: one for the coordinated phosphine groups, and one
attributable to unbound phosphine at about Ϫ16 ppm. The
former resonances are different in each derivative. Thus, the
copper compound 6 displays a broad singlet at 4.8 ppm, even at
low temperature; complex 7 displays a doublet of doublets as a
consequence of the 107Ag and 109Ag nucleus coupling; and the
gold derivative 8 shows one A2B2 spin system. The presence of
such a system in the case of the gold complex indicates that the
four phosphorus atoms are grouped in two pairs with a slight
difference between them. This fact could be explained consider-
ing that the gold center is coordinated in a different way to the
two pairs of P atoms. Unfortunately, we were not able to grow
crystals suitable for X-ray analysis. In the case of the copper
and silver derivatives we can imagine a tetrahedral geo-
metry around the metallic centers, similar to those described
in [M(o-P2)2]BF4 (M = Ag, Cu) complexes with o-P2 =
3,4-dimethyl-3Ј,4Ј-bis(diphenylphosphino)tetrathiafulvalene.11
The P4 ligand contains four binding sites in a trans position
that can be used to join metals in oligomeric arrays. Working
with this idea, we have investigated the reaction of P4 with
gold() and silver() derivatives in a 1:1 molar ratio. Ratios
of 1:2 or 1:4 have also been studied. In all the reactions only
one stoichiometry is obtained, which can be represented by the
general formula {[M2P4](CF3SO3)2}n (M = Ag, 9; Au, 10).
gold() complexes.19 The distances in the P4 core [C᎐C:
᎐
1.310(19), 1.358(12) Å and C–S: 1.773(9) and 1.752(8) Å] are
similar to those found in the free phosphine. These data suggest
that there a is non-important electronic change in the dithiole
system due to the electronic donation of the phosphorus to the
metal center. Apart from the intramolecular gold–gold inter-
action, there is an additional intermolecular contact of 3.402 Å
between Au(1) and one chlorine atom from the CH2Cl2 solvent
molecule, as is shown in Fig. 5. The packing of the molecules
results in intermolecular distances of 7.303 Å (Fig. 5) between
them. The Au–P [2.216(3), 2.233(2) Å] and Au–Cl [2.278(3),
2.288(3) Å] bond lengths are in the range of those found
in dinuclear gold() derivatives with a bis-phosphine20–23 as
bidentate ligand.
When the same reaction described above is carried out with
[Au(Trip)(AsPh3)] (process ii, Scheme 1), where Trip = 2,4,6-
Pri3C6H2 acts as a bulky radical, the results obtained, independ-
ently of the molar ratio used, give a dinuclear derivative with
two Trip radicals instead of the homologous tetranuclear com-
plexes 2–4. Thus, [(AuTrip)2P4] (5) can be isolated as an air-
stable solid. As occurred in complexes 2–4 the 31P{1H} NMR
spectra display a singlet due to the equivalence of the four
1
In the H NMR spectra only signals corresponding to the
PPh2 groups are present in accordance with the proposed
stoichiometry. The 31P{1H} NMR spectra display a doublet of
doublets centered at Ϫ1.1 ppm in 9, due to the presence of the
109Ag and 107Ag isotopomers and a singlet at 17.5 ppm in the
gold compound. In the 19F{1H} NMR spectra appear one
singlet in both cases centered at about Ϫ77.8 ppm, attributable
to the presence of an anionic triflate.26
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J. Chem. Soc., Dalton Trans., 2002, 1104–1109

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[Au(Mes)(AsPh3)]17 and [Au(Trip)(AsPh3)]28 were synthesised
Table 3 Cyclic voltammetric data for P4 and related complexes
(V vs. SCE, Pt disk electrode in 0.1 M of NBu4PF6)
as previously reported. All other reagents were used as sup-
plied. IR spectra were recorded on a Perkin Elmer 883 spectro-
photometer, over the range 4000–200 cmϪ1, using KBr pellets.
1H, 31P and 19F NMR spectra were measured on a Varian
UNITY 300 or BRUKER 300 spectrometer in CDCl3 or
(CD3)2CO solution; chemical shifts are quoted relative to SiMe4
(1H), H3PO4 (external, 31P) and CFCl3 (external, 19F). The C, H,
N and S analyses were performed with a Perkin Elmer 2400
microanalyser. Mass spectra were recorded on a VG Autospec,
by liquid secondary ion mass spectrometry (LSIMSϩ) using
nitrobenzyl alcohol as matrix and a caesium gun. UV-vis
spectra were recorded on a Unicam spectrometer in CH2Cl2
or MeCN solutions. Electrochemical measurements were
recorded on a EG&G 273 model and carried out in dry CH2Cl2
or MeCN under argon using [n-NBu4]PF6 (0.1 M) as back-
ground electrolyte, with a Pt disk electrode versus SCE (values
in V)
Donor
E 11/2/V
E(ox)/V
E 21/2/V
1; P4
0.33
0.83
0.76
0.71
0.57
0.61
0.39
0.64
0.82
0.79
0.73
1.21
1.16
1.12
1.27
0.81
0.77
1.3
2; [(AuCl)4P4]
3; [(AuC6F5)4P4]
4; [(AuMes)4P4]
5; [(AuTrip)2P4]
6; [Cu(P4)2](PF6)
7; [Ag(P4)2](CF3SO3)
8; [Au(P4)2](CF3SO3)
9; {[Ag2P4](CF3SO3)2}n
10; {[Au2P4](CF3SO3)2}n
1.07
0.59
1.11
1.08
The mass spectra (LSIMSϩ) show the molecular peak only
in the case of the silver complex, in addition to lower peaks due
to the fragmentation of the molecule and even higher peaks at
m/z(%) = 1307 (12), 1989 (15) and 2247 (10) associated with
[M ϩ CF3SO3]ϩ, [M ϩ P4]ϩ, [M ϩ P4 ϩ CF3SO3]ϩ, respectively.
In complex 10 the highest peak, m/z = 1137, corresponds to the
loss of one gold center.
Unfortunately, in the absence of single crystal X-ray data, we
cannot draw any definitive conclusions about the nature of
these complexes.
Syntheses
[(AuX)4P4] [X ؍ Cl (2); C6F5 (3); Mes (4)]. To a solution of
P4 (0.094 g, 0.1 mmol) in 10 ml of dichloromethane was added
[AuCl(tht)] (0.128 g, 0.4 mmol), [Au(C6F5)(tht)] (0.180 g,
0.4 mmol) or [Au(Mes)(AsPh3)] (0.248 g, 0.4 mmol). After 2 h
of stirring, the solutions were concentrated and the addition of
n-hexane led to the precipitation of pink (2,3) or red (4) solids,
which were filtered off, washed with hexane and dried in vacuo.
Yields: 2, 83%; 3, 78%; 4, 55%.
2: Found: C, 34.29; H, 2.35; S, 6.68. C54H40Cl4P4S4Au4
requires: C, 34.67; H, 2.15; S, 6.85%. 1H NMR (CDCl3):
δ 7.35–7.68 (m, Ph). 31P{1H} NMR (CDCl3): δ 19.1 (s). UV-vis
(CH2Cl2): λmax (nm) (ε, MϪ1 cmϪ1): 212 (7003), 252 (19588), 320
(13507), 432 (1591). CV (CH2Cl2): E 11/2 = 0.83 V, E 21/2 = 1.21 V.
LSIMSϩ: m/z (%) 1868 (50, Mϩ), 1832 (100, [M Ϫ Cl]ϩ), 1597
(10, [M Ϫ AuCl2]ϩ).
Visible-ultraviolet studies
The electronic absorbance spectra reveal, in all cases, the char-
acteristic phenyl- and TTF-based transitions, which in the case
of the free P4 phosphine appear at 212, 252, 320 and 432 nm.
The extinction coeficients (ε) of these TTF bands are consistent
with the number of chromophores in the molecule, when o-P2
is used as the TTF-functionalized phosphine.7,9 We can extend
these considerations to the case of (PPh2)4TTF. Thus, on the
basis that P4, with four PPh2 units (eight phenyl rings), shows a
transition at 252 nm and has an ε of ca. 25000, complexes 2–5,
9 and 10 show a slightly displaced transition from the value of
252 nm with similar ε values; however, complexes 6–8 display a
double of the ε coefficient. With these data we assume the
presence of only one P4 unit in complexes 2–5, 9 and 10 and
exactly double this number for complexes 6–8.
3: Found: C, 39.05; H, 1.82; S, 5.46. C78H40F20P4S4Au4
requires: C, 39.08; H, 1.68; S, 5.35%. 1H NMR (CDCl3):
δ 7.33–7.66 (m, Ph). 31P{1H} NMR (CDCl3): δ 21.3 (s). 19F
NMR: δ Ϫ117.1 (m, Fo), Ϫ161.21 (t, Fp), Ϫ165.5 (t, Fm). UV-vis
(CH2Cl2): λmax (nm) (ε, MϪ1 cmϪ1): 212 (10699), 272 (27577),
325 (14712), 485 (668). CV (CH2Cl2): E 1 = 0.76 V, E 2
=
1/2
1/2
1.16 V. LSIMSϩ: m/z (%) 2395 (30, Mϩ), 2229 (15, [M Ϫ C6F5]ϩ),
2032 (20, [M Ϫ AuC6F5]ϩ), 1668 (12, [M Ϫ 2AuC6F5]ϩ).
4: Found: C, 49.47; H, 3.7; S, 6.15. C90H84P4S4Au4 requires:
C, 49.01; H, 3.35; S, 5.81%. 1H NMR (CDCl3): δ 7.33–7.63 (m,
40H, Ph), 6.59 (s, 8H), 2.17 (s, 12H, p-Me), 1.82 (s, 24H, m-Me).
31P{1H} NMR (CDCl3): δ 30.9 (s). UV-vis (CH2Cl2): λmax (nm)
(ε, MϪ1 cmϪ1): 212 (17164), 293 (39925), 480 (1865). CV
(CH2Cl2): E 11/2 = 0.71 V, E 21/2 = 1.12 V. LSIMSϩ: m/z (%) 2085
(35, [M Ϫ Mes]ϩ), 1453 (55, [M Ϫ 2Au Ϫ 3Mes]ϩ), 1137 (20,
[P4 ϩ Au]ϩ).
Electrochemical studies
Cyclic voltammetry experiments display two, reversible one-
electron oxidations to the mono- and di-cation species in all of
the new complexes (Table 3). These oxidations occur at more
positive potentials than the two reversible oxidations exhibited
by the free P4 ligand,6 except in the case of complex 7 where the
values are similar to those found in the phosphine P4. This shift
to higher potentials can be understood as a result of strong
metal–P interactions. In the case of complexes 4 and 7 an
additional oxidation process, without any reduction curve, is
observed at E(ox) = 1.07 V (4) and 0.59 V (7), that can be
assigned to a one-electron oxidation of the corresponding
metal.
In conclusion, we have studied here the versatility of (PPh2)4-
(TTF), whose structure has been presented, in the chemistry of
group 11 metals. It can act as a bidentate or tetradentate ligand
depending on the phosphine/metallic complex used, and
regarding gold chemistry it affords two-, three- and four-
coordinated gold() complexes. The two, reversible one-electron
oxidations of (PPh2)4(TTF) are retained after the coordination,
although they appear at higher potentials that in the free
phosphine.
[(AuTrip)2P4] (5). This was prepared as above starting from
P4 (0.094 g, 0.1 mmol) and [Au(Trip)(AsPh3)] (0.140 g,
0.2 mmol). Yield: 70%. Found: C, 57.61; H, 4.82; S, 6.95.
1
C84H86P4S4Au2 requires: C, 57.92; H, 4.97; S, 7.36%. H NMR
(CDCl3): δ 7.21–7.45 (m, 40H, Ph), 6.95 (s, 4H, m-H), 3.69 (sep,
4H, o-CHMe2), 2.80 (sep, 2H, p-CHMe2), 1.2 (d, 36H, J =
12 Hz, p-CHMe2). 31P{1H} NMR (CDCl3): δ 9.6 (s). UV-vis
(CH2Cl2): λmax (nm) (ε, MϪ1 cmϪ1): 296 (35211), 347 (32042),
460 (2464). CV (CH2Cl2): E 1 = 0.57 V, Eox = 1.07 V, E 2
=
1/2
1/2
1.27 V. LSIMSϩ: m/z (%) 1741 (5, Mϩ), 1537 (10, [M Ϫ Trip]ϩ),
1136 (6, [P4 ϩ Au]ϩ), 1938 (6, [M ϩ Au]ϩ).
[M(P4)2]A [M ؍ Cu (6), A ؍ PF6; M ؍ Ag (7), A ؍ CF3SO3;
M ؍ Au (8), A ؍ CF3SO3]. To a solution of P4 (0.188 g,
0.2 mmol) in 10 ml of dichloromethane under argon was added
[Cu(MeCN)4](PF6) (0.037 g, 0.1 mmol), AgCF3SO3 (0.025 g,
0.1 mmol) or [Au(tht)2](CF3SO3) (0.052 g, 0.1 mmol). After 3 h
Experimental
General procedure
Starting materials: P4 (1),6 [AuCl(tht)],27 [Au(C6F5)(tht)],27
J. Chem. Soc., Dalton Trans., 2002, 1104–1109
1107

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Table 4 Summary of crystallographic data for derivatives P4ؒCHCl3 (1) and [(AuCl)4P4]ؒCH2Cl2 (2)
Parameter
1
2
Empirical formula
M
C55H41Cl3P4S4
1060.35
C56H42Au4Cl8P4S4
2038.48
T /K
Crystal system
Space group
150(2)
150(2)
Monoclinic
P21/n
Triclinic
¯
P1
a/Å
b/Å
c/Å
α/Њ
9.6800(9)
11.7691(10)
12.6621(12)
72.829(6)
69.653(4)
82.261(5)
1291.4(2)
1
11.362(2)
17.624(4)
15.911(3)
90
104.99(3)
90
3077.7(11)
2
2.200
β/Њ
γ/Њ
V/Å3
Z
Dc/Mg mϪ3
1.363
0.500
µ/mmϪ1
10.129
Crystal size/mm
θ Range/Њ
0.30 × 0.20 × 0.01
2.94–23.26
0.0587, 0.1614
0.571, Ϫ0.558
0.25 × 0.2 × 0.05
2.96–25.03
0.0485, 0.1349
2.110, Ϫ3.008
R1a, wR2b [I > 2σ(I )]
Max., min. residual density/e ÅϪ3
2
a R1 = Σ||Fo| Ϫ Σ|Fc||/|Fo|. b wR2 = {Σ[w(Fo2 Ϫ Fc2)]/Σ[w(Fo )2]}1/2
.
of stirring, the solutions were concentrated and the addition of
ethanol led to the precipitation of orange (6, 7) and red (8)
solids, which were filtered off, washed with ethanol and dried
in vacuo. Yields: 6, 70%; 7, 60%; 8 60%.
281 (36377), 316 (30805). CV (MeCN): E 1 = 0.79 V, E 2
=
1/2
1/2
1.08 V. LSIMSϩ: m/z (%) 1137 (10, [M Ϫ Au]ϩ).
X-Ray studies
6: Found: C, 61.75; H, 3.86; S, 11.93. C108H80P9S8F6Cu
requires: C, 62.05; H, 3.85; S, 12.26%. 1H NMR (HDA): δ 7.15–
7.49 (m, Ph). 31P{1H} NMR: δ 4.8 (s, br), Ϫ16.8 (s), Ϫ142.9
(sep). 19F NMR: δ Ϫ70.6 (d, JP–F = 702 Hz). UV-vis (CH2Cl2):
λmax (nm) (ε, MϪ1 cmϪ1): 296 (52236), 327 (42163), 470 (8524).
CV (CH2Cl2): E 1 = 0.61 V, E 2 = 0.81 V. LSIMSϩ: m/z (%)
Single crystals of P4ؒCHCl3 (1) and [(AuCl)4P4]ؒCH2Cl2 (2)
were grown by slow diffusion of hexane into chloroform or
dichloromethane solutions of their derivatives. Data collection
at low temperature was carried out on a Bruker Nonius Kappa
CCD diffractometer. Crystal parameters and experimental
details are summarised in Table 4. The structures were solved by
direct methods29 and refined on F 2 by full-matrix, least squares
using the program SHELXL-97.30 Data were corrected for
absorption using the SORTAV31 program. All hydrogen atoms
were located in geometric positions and refined using a riding
model. In the case of 1 the CHCl3 solvent molecule is dis-
ordered over two sites, each half occupied related by a centre; in
2 there is high thermal motion in the CH2Cl2 solvent molecule.
Selected bond lengths and angles are given in Tables 1 and 2.
CCDC reference numbers 166713 and 166714.
1/2
1/2
1945 (6, Mϩ).
7: Found: C, 60.78; H, 4.05; S, 13.14. C109H80O3P8S9F3Ag
requires: C, 61.2; H, 3.77; S, 13.48%. 1H NMR (HDA):
δ 7.18–7.48 (m, Ph). 31P{1H} NMR (HDA, Ϫ85 ЊC): δ Ϫ1.3 (dd,
J107
= 235, J109
= 270 Hz (s), Ϫ16.7 (s). 19F NMR:
Ag–P
δ Ϫ77.8 (s). UV-vAigs–P (CH2Cl2): λmax (nm) (ε, MϪ1 cmϪ1): 297
(45300), 321 (42779), 470 (3461). CV (CH2Cl2): E 11/2 = 0.39 V,
Eox = 0.59 V, E 2 = 0.77 V. LSIMSϩ: m/z (%) 1990 (5, Mϩ),
1/2
1050 (15, [P4 ϩ Ag]ϩ).
8: Found: C, 58.41; H, 3.49; S, 13.10. C109H80O3P8S9F3Au
requires: C, 58.75; H, 3.61; S, 12.95%. 1H NMR (HDA):
δ 7.25–7.66 (m, Ph). 31P{1H} NMR (HDA): δ (A2B2) δA = 18.1,
δB = 17.6, Ϫ16.8 (s). 19F NMR: δ Ϫ77.8 (s). UV-vis (CH2Cl2):
λmax (nm) (ε, MϪ1 cmϪ1): 268 (47491), 324 (25295), 463 (3846).
CV (CH2Cl2): E 1 = 0.64 V, E 2 = 1.3 V. LSIMSϩ: m/z (%)
See http://www.rsc.org/suppdata/dt/b1/b106310n/ for crystal-
lographic data in CIF or other electronic format.
Acknowledgements
1/2
1/2
We thank the Spanish Directorate General for Higher
Education and Scientific Research PB98–0542 for financial
support. M. B. H. thanks the Engineering and Physical Sciences
Research Council for support of the X-ray facilities.
2078 (30, Mϩ), 1137 (15, [M Ϫ P4]ϩ), 940 (30, [P4]ϩ).
{[M2P4](CF3SO3)2}n [M ؍ Ag (9); Au (10)]. To a solution of
P4 (0.094 g, 0.1 mmol) in 10 ml of dichloromethane was added
[Au(tht)2](CF3SO3) (0.104 g, 0.2 mmol) or AgCF3SO3 (0.051 g,
0.2 mmol). After 2 h of stirring, the solutions were concen-
trated and the addition of ethanol led to the precipitation of
orange solids, which were filtered off, washed with ethanol and
dried in vacuo. Yields: 9, 75%: 10, 50%.
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