Substitution Reaction Studies on [Au2Cl2(μ-dppf)] (dppf = 1,1′-Bis(diphenylphosphino)ferrocene). Synthesis of the First Gold(I) Complex with a μ3-2-Pyridinethiolate Ligand

Article abstract of DOI:10.1021/ic9704445

Substitution of the chlorine ligand in the complex [Au₂Cl₂(μ-dppf)] by other halogens or anionic ligands such as Spy^- (2-pyridinethiolate) or S₂CNR₂^- have been carried out. The complexes [Au₂(Spy)₂(μ-dppf)] and [Au₂(S₂-CNR₂)₂(μ-dppf)] possess a nitrogen or sulfur donor atom that can coordinate to a metallic fragment; thus reactions of these complexes with [Au(OTf)(PR₃)] in various molar ratios have been studied. The crystal structures of [Au₂I₂(μ-dppf)], [Au₂Cl₂(μ-dppf)], and [Au₃(μ₃-Spy)(μ-dppf)(PPh₂Me)](OTf) ₂ have been established by X-ray diffraction studies. The last represents the first example where a pyridinethiolate ligand bridges three gold atoms.

Full text of DOI:10.1021/ic9704445

5206
Inorg. Chem. 1997, 36, 5206-5211
Substitution Reaction Studies on [Au2Cl2(µ-dppf)] (dppf )
1,1′-Bis(diphenylphosphino)ferrocene). Synthesis of the First Gold(I) Complex with a
µ3-2-Pyridinethiolate Ligand
Fernando Canales,† M. Concepcio´n Gimeno,† Peter G. Jones,‡ Antonio Laguna,*,† and
Cristina Sarroca†
Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n, Universidad de
Zaragoza-CSIC, 50009 Zaragoza, Spain, and Institut fu¨r Anorganische und Analytische Chemie,
Technische Universita¨t Braunschweig, Postfach 3329, D-38023 Braunschweig, Germany
ReceiVed April 16, 1997X
Substitution of the chlorine ligand in the complex [Au2Cl2(µ-dppf)] by other halogens or anionic ligands such as
Spy- (2-pyridinethiolate) or S2CNR2- have been carried out. The complexes [Au2(Spy)2(µ-dppf)] and [Au2(S2-
CNR2)2(µ-dppf)] possess a nitrogen or sulfur donor atom that can coordinate to a metallic fragment; thus reactions
of these complexes with [Au(OTf)(PR3)] in various molar ratios have been studied. The crystal structures of
[Au2I2(µ-dppf)], [Au2Cl2(µ-dppf)], and [Au3(µ3-Spy)(µ-dppf)(PPh2Me)](OTf)2 have been established by X-ray
diffraction studies. The last represents the first example where a pyridinethiolate ligand bridges three gold atoms.
Introduction
gold(I) derivatives have been obtained, most of them with the
ligand acting as an S-donor ligand.7 Thus we have prepared
several gold-dppf derivatives with 2-pyridinethiolate or dithio-
carbamate ligands acting as µ2 and µ3 ligands. The structure
of [Au3(µ3-Spy)(µ-dppf)(PPh2Me)](OTf)2 has been established
by X-ray diffraction and represents the first example of a gold
species with a triply bridging pyridinethiolate ligand.
Ferrocene-containing complexes are currently receiving much
attention associated with their increasing role in the rapidly
growing area of materials science. Because of its high stability
and the well-established methods for its incorporation into more
complex structures, ferrocene has become a versatile building
block for the synthesis of compounds with tailormade proper-
ties.1 The diphosphine 1,1′-bis(diphenylphosphino)ferrocene
(dppf), although synthesized more than two decades ago,2 has
only recently received much attention because of its chemical
uniqueness and industrial importance. Its catalytic potential is
important because of the increasing use of homogeneous
catalysis in organic synthesis and production of materials and
fine chemicals.1,3
We previously reported on gold and silver complexes with
the 1,1′-bis(diphenylphosphine)ferrocene ligand.4 Here we have
studied substitution reactions of the compound [Au2Cl2(µ-dppf)],
both with other halogen ligands and with homo- or heterodi-
functional ligands such as 2-pyridinethiolate or diethyldithio-
carbamate. These ligands have been extensively used because
of their versatile coordination behavior. In particular, 2-py-
ridinethiolate can act as a monodentate (as S- or N-donor)5 or
bidentate ligand, in the latter mode either chelating or bridging
two, three, or even four metal centers.6 In contrast, only a few
Results and Discussion
The reaction of [Au2Cl2(µ-dppf)] 1 (dppf ) 1,1′-bis(diphen-
ylphosphino)ferrocene) with KX in acetone leads to the
substitution of the chlorine ligand to give [Au2X2(µ-dppf)] (X
) Br (2), I (3)). Complexes 2 and 3 are nonconducting in
acetone.
The 31P{1H} NMR spectra show a singlet for the equivalent
1
phosphorus atoms. In the H NMR spectra, three multiplets
with an intensity ratio 1:1:5 appear, corresponding to the R and
â cyclopentadienyl protons and the phenyl groups, respectively.
In the positive-ion mass spectra (FAB+) of complexes 2 and
3, the molecular peak is not present but the peaks arising from
the loss of one bromine or iodine atom appear at m/z ) 1026
(2, 100%, [Au2Br(dppf)]+) and 1075 (3, 100%, [Au2I(dppf)]+).
The structures of complexes 1 (as a bis(dichloromethane)
solvate) and 3 have been established by X-ray diffraction
2
methods. The structure of the /3 chloroform solvate of 1 was
† Universidad de Zaragoza-CSIC.
‡ Technische Universita¨t Braunschweig.
(5) (a) Raper, E. S. Coord. Chem. ReV. 1985, 61, 115 and references
therein. (b) McCleverty, J. A.; Gill, S.; Kowalski, R. S. Z.; Bailey, N.
A.; Adams, H.; Lumbard, K. W.; Murphy, M. A. J. Chem. Soc., Dalton
Trans. 1982, 493.
(6) (a) Castro, R.; Dura´n, M. L.; Garc´ıa-Va´zquez, J. A.; Romero, J.; Sousa,
A.; Castin˜eiras, A.; Hiller, W.; Stra¨hle, J. J. Chem. Soc., Dalton Trans.
1990, 531. (b) Zhang, N.; Wilson, S. R.; Shapley, P. A. Organome-
tallics 1988, 7, 1126. (c) Kitagawa, S.; Munakata, M.; Shimono, H.;
Marsuyana, S.; Masuda, H. J. Chem. Soc., Dalton Trans. 1990, 2105.
(d) Deeming, A. J.; Hardcastle, K. I.; Karim, M. Inorg. Chem. 1992,
31, 4792.
(7) (a) Uso´n, R.; Laguna, A.; Laguna, M.; Jime´nez, J.; Go´mez, M. P.;
Sainz, A.; Jones, P. G. J. Chem. Soc., Dalton Trans. 1990, 3457. (b)
Jia, G.; Puddephatt, R. J.; Vittal, J. J. Polyhedron 1992, 11, 2009. (c)
Cookson, P. D.; Tiekink, E. R. T. J. Chem. Soc., Dalton Trans. 1993,
259. (d) Vicente, J.; Chicote, M. T.; Gonzalez-Herrero, P.; Jones, P.
G. J. Chem. Soc., Dalton Trans. 1994, 3183. (e) Bardaj´ı, M.; Connelly,
N. G.; Gimeno, M. C.; Jones, P. G.; Laguna, A.; Laguna, M. J. Chem.
Soc., Dalton Trans. 1995, 2245.
X Abstract published in AdVance ACS Abstracts, October 1, 1997.
(1) Ferrocenes. Homogeneous Catalysis, Organic Synthesis and Materials
Science; Togni, A., Hayashi, T., Eds.; VCH: Weinheim, Germany,
1995 (and references cited therein).
(2) (a) Sollot, G. P.; Snead, J. L.; Portnoy, S.; Peterson, W. R., Jr.;
Mertway, H. E. Chem. Abstr. 1965, 63, 18147b. (b) Bishop, J. J.;
Davison, A.; Katcher, M. L.; Lichtenberg, D. W.; Merril, R. E.; Smart,
J. C. J. Organomet. Chem. 1971, 27, 241. (c) Marr, G.; Hunt, T. J.
Chem. Soc. C 1969, 1070.
(3) See, for example: (a) Cullen, W. R.; Woollins, J. D. Coord. Chem.
ReV. 1982, 39, 1. (b) Hayashi, T.; Kumuda, M. Acc. Chem. Res. 1982,
15, 395.
(4) (a) Gimeno, M. C.; Jones, P. G.; Laguna, A.; Sarroca, C. Inorg. Chem.
1993, 32, 5926. (b) Gimeno, M. C.; Jones, P. G.; Laguna, A.; Sarroca,
C. J. Chem. Soc., Dalton Trans. 1995, 1473. (c) Canales, F.; Gimeno,
M. C.; Jones, P. G.; Laguna, A. J. Am. Chem. Soc. 1996, 118, 4839.
(d) Canales, F.; Gimeno, M. C.; Jones, P. G.; Laguna, A. Organo-
metallics 1996, 15, 3412.
S0020-1669(97)00444-8 CCC: $14.00 © 1997 American Chemical Society

Substitution Reactions of [Au2Cl2(µ-dppf)]
Inorganic Chemistry, Vol. 36, No. 23, 1997 5207
Figure 1. The molecule of complex 1 in the crystal showing the atom-
numbering scheme. Radii are arbitrary. H atoms are omitted for clarity.
Figure 2. Molecular structure of complex 3 in the crystal. H atoms
are omitted for clarity.
Table 1. Selected Bond Lengths (Å) and Angles (deg) for 1
Table 2. Selected Bond Lengths (Å) and Angles (deg) for 3
Au-P
2.2262(13)
2.040(5)
2.046(5)
2.063(5)
1.809(5)
1.424(7)
1.413(8)
1.415(8)
1.399(7)
1.387(7)
1.377(7)
1.393(7)
1.376(8)
1.379(8)
1.728(8)
Au-Cl
2.2815(13)
2.044(5)
2.052(5)
1.787(5)
1.814(5)
1.437(7)
1.409(9)
1.385(7)
1.372(7)
1.382(7)
1.386(7)
1.400(8)
1.383(9)
1.776(8)
Au(1)-P(1)
Au(2)-P(2)
2.248(9)
2.240(8)
Au(1)-I(1)
Au(2)-I(2)
2.545(3)
2.561(2)
Fe-C(1)
Fe-C(5)
Fe-C(2)
Fe-C(3)
P(1)-Au(1)-I(1)
177.7(2)
P(2)-Au(2)-I(2)
176.3(2)
Fe-C(4)
P-C(1)
C(41)-P(1)-C(31) 104.2(10) C(41)-P(1)-C(11) 105.3(10)
P-C(11)
P-C(21)
C(31)-P(1)-C(11) 106.2(10) C(41)-P(1)-Au(1) 113.4(8)
C(1)-C(5)
C(2)-C(3)
C(4)-C(5)
C(11)-C(16)
C(13)-C(14)
C(15)-C(16)
C(21)-C(26)
C(23)-C(24)
C(25)-C(26)
Cl(2)-C(99)
C(1)-C(2)
C(3)-C(4)
C(11)-C(12)
C(12)-C(13)
C(14)-C(15)
C(21)-C(22)
C(22)-C(23)
C(24)-C(25)
Cl(1)-C(99)
C(31)-P(1)-Au(1) 114.4(8)
C(11)-P(1)-Au(1) 112.5(8)
C(51)-P(2)-C(21) 108.5(10) C(51)-P(2)-C(61) 103.2(11)
C(21)-P(2)-C(61) 103.7(10) C(51)-P(2)-Au(2) 113.9(8)
C(21)-P(2)-Au(2) 111.4(8)
C(61)-P(2)-Au(2) 115.3(7)
longer than those in 1, 2.248(9) and 2.240(8) Å, although similar
to those in [AuI(PR3)] (2.256(3) Å, PMe3; 2.249(2) Å, PPh3).
The higher trans influence of the iodine compared to the chlorine
ligand is presumably the factor responsible for the elongation
of the Au-P distances in complex 3. The cyclopentadienyl
rings adopt a staggered conformation.
P-Au-Cl
179.59(5)
105.7(2)
113.4(2)
111.7(2)
C(1)-P-C(11)
C(11)-P-C(21)
C(11)-P-Au
107.3(2)
103.4(2)
114.4(2)
C(1)-P-C(21)
C(1)-P-Au
C(21)-P-Au
We have carried out further substitution reactions on complex
1 with other anionic ligands such as pyridinethiolate (Spy-) and
dithiocarbamate (S2CNR2-) with the aim of studying further
coordination reactions of the nitrogen or sulfur donor atoms
present in these ligands. Thus the treatment of 1 with NaSpy
or NaS2CNEt2 in dichloromethane affords the species [Au2-
(SR)2(µ-dppf)] (SR ) Spy (4), S2CNEt2 (5)) in good yields.
Complexes 4 and 5 behave as nonconductors in acetone. In
their IR spectra the vibrations ν(CdN) corresponding to the
pyridinethiolate or dithiocarbamate ligands are observed at 1573
already known;8 there the compound crystallized with two
independent molecules, one of which displayed inversion
symmetry. The molecule of 1 in the current structure is shown
in Figure 1; selected bond lengths and angles are collected in
Table 1. The iron atom lies on a symmetry center. The dppf
ligand coordinates the metal centers in an open bridging mode.
The P-Au-Cl angle is 179.59(5)°, very close to the ideal linear
value. The Au-P and the Au-Cl bond distances are 2.2262-
(13) and 2.2815(13) Å, respectively, which are similar to those
found in the earlier determination [Au-P 2.222-2.239, Au-
Cl 2.273-2.300 Å]8 and in the complex [AuCl(PPh3)].9 The
cyclopentadienyl ring is planar and located 1.655(2) Å from
the iron atom; by symmetry, both Cp rings are parallel and
staggered. There is no Fe-Au interaction, with the shortest
such distance being 4.29(1) Å. In contrast to the other
modification,8 there is no short Au‚‚‚Au contact (none <5.78Å).
The molecule of complex 3 is shown in Figure 2, and selected
bond lenghts and angles are given in Table 2. It too crystallizes
with two molecules of dichloromethane, but 1 and 3 are not
isostructural. The coordination around the gold atoms is linear
with P-Au-I angles of 177.7(2) and 176.3(2)°. The Au-I
distances are 2.545(3) and 2.561(2) Å; these fall in the range
found for complexes of the type [AuI(PR3)]10 (2.583(1) Å,
PMe3; 2.553(1) Å, PPh3). The Au-P distances are slightly
(m) and 1550 (s) (Spy-) and 1482 (m) (S2CNEt2-) cm-1
.
The 1H NMR spectra show, apart from the multiplets arising
from the phenyl protons, the two multiplets assigned to the R
and â protons of the cyclopentadienyl rings; furthermore, 4
presents the four resonances for the protons of the equivalent
pyridine groups and 5 a quartet and a triplet for the ethyl protons
of the dithiocarbamate. In the 31P{1H} NMR, only one
resonance appears for the two equivalent phosphorus atoms.
In the positive-ion fast-atom bombardment (FAB+) mass
spectra, the molecular peaks do not appear but the fragments
arising from the loss of one ionic ligand, similar to those
observed for complexes 1-3, are the most abundant; this peak
appears for 4 at m/z ) 1096 and for 5 at m/z ) 1057.
As mentioned above, complexes 4 and 5 offer the possibility
of studying further coordination reactions of metallic frag-
ments. Thus the treatment of these complexes with 2 equiv of
[Au(OTf)(PPh2Me)] (OTf ) trifluoromethanesulfonate) or [Au-
(OClO3)(PPh2Me)] in dichloromethane affords the species
[Au4(µ-SR)2(µ-dppf)(PPh2Me)2]X2 (SR ) Spy (6), X )
OTf; SR ) S2CNEt2 (7), X ) ClO4). Their NMR spectra
present the same resonances as the starting materials and
additionally those arising from the tertiary phospine, which are
(8) Hill, D. T.; Girard, G. R.; McCabe, F. L.; Johnson, R. K.; Stupik, P.
D.; Zhang, J. H.; Reiff, W. M.; Eggleston, D. S. Inorg. Chem. 1989,
28, 3529.
(9) Baenziger, N. C.; Dittemore, K. M.; Doyle, J. R. Inorg. Chem. 1974,
13, 805.
(10) Ahrland, S.; Dreisch, K.; Nore´n, B.; Oskarsson, A. Acta Chem. Scand.,
Ser. A 1987, 41, 173.

5208 Inorganic Chemistry, Vol. 36, No. 23, 1997
Canales et al.
Scheme 1a
a Key: (i) 2 KX; (ii) 2 HSpy + Na2CO3 or NaS2CNEt2; (iii) [Ag(OTf)(PPh3)] or Ag(OTf); (iv) 2 [Au(OTf)(PPh2Me)] or 2 [Au(OClO3)(PPh2Me)];
(v) 4 [Au(OTf)(PR3)]; (vi) decomposition; (vii) [Au(OTf)(PPh2Me)].
Table 3. Selected Bond Lengths (Å) and Angles (deg) for 12
Au(1)-P(1)
Au(1)-Au(3)
Au(2)-N(91)
Au(3)-P(3)
2.246(4)
Au(1)-S(1)
Au(1)-Au(2)
Au(2)-P(2)
Au(3)-S(1)
2.341(4)
3.2105(13)
2.239(5)
2.337(6)
3.0985(12)
2.065(14)
2.252(6)
P(1)-Au(1)-S(1)
S(1)-Au(1)-Au(3)
S(1)-Au(1)-Au(2)
177.9(2)
P(1)-Au(1)-Au(3) 129.55(14)
48.47(14) P(1)-Au(1)-Au(2) 114.59(14)
67.23(14) Au(3)-Au(1)-Au(2) 115.12(3)
N(91)-Au(2)-P(2) 173.3(5)
N(91)-Au(2)-Au(1) 76.6(5)
P(2)-Au(2)-Au(1) 110.00(14) P(3)-Au(3)-S(1)
P(3)-Au(3)-Au(1) 128.27(13) S(1)-Au(3)-Au(1)
C(92)-S(1)-Au(3) 108.1(6)
Au(3)-S(1)-Au(1) 83.0(2)
176.8(2)
48.56(10)
96.5(5)
C(92)-S(1)-Au(1)
C(11)-P(1)-C(41) 103.3(7)
C(41)-P(1)-C(31) 107.5(7)
C(41)-P(1)-Au(1) 114.1(4)
C(21)-P(2)-C(51) 107.8(7)
C(51)-P(2)-C(61) 104.5(7)
C(51)-P(2)-Au(2) 109.0(5)
C(77)-P(3)-C(81) 109.0(10)
C(11)-P(1)-C(31) 106.1(6)
C(11)-P(1)-Au(1) 115.3(5)
C(31)-P(1)-Au(1) 109.9(5)
C(21)-P(2)-C(61) 105.8(7)
C(21)-P(2)-Au(2) 116.5(5)
C(61)-P(2)-Au(2) 112.5(5)
Figure 3. The cation of complex 12 in the crystal. H atoms are omitted
for clarity.
1
a doublet for the methyl protons in the H NMR spectra and a
singlet for the equivalent phosphorus atoms in the 31P{1H} NMR
spectra.
C(77)-P(3)-C(71) 102.4(10) C(81)-P(3)-C(71) 104.4(7)
The positive-ion fast-atom bombardment (FAB+) mass
spectra of 6 and 7 do not show the molecular peaks as expected
for dicationic species; however, the fragments arising from the
loss of one ClO4- or OTf-, respectively, appear at m/z ) 2111
(6, 2%) and 2137 (7, 45%).
C(77)-P(3)-Au(3) 113.8(9)
C(71)-P(3)-Au(3) 115.4(6)
C(81)-P(3)-Au(3) 111.1(5)
C(92)-N(91)-C(96) 118(2)
C(92)-N(91)-Au(2) 121.0(13) C(96)-N(91)-Au(2) 121.0(14)
formation of [Ag(Spy)]n and [Ag(S2CNEt2)]n may be due to
their insolubility in the reaction media.
Similar reactions have been carried out with silver complexes,
but in this case the result is different because we obtain the
same complexes irrespective of the silver precursor used. Thus
the treatment of 4 or 5 with [Ag(OTf)PR3] or AgOTf affords
the dinuclear gold complexes bridged by two different ligands,
[Au2(µ-SR)(µ-dppf)]OTf (SR ) Spy (8), S2CNEt2 (9)), and the
formation of [Ag(Spy)]n or [Ag(S2CNEt2)]n. The ease of
Complexes 8 and 9 behave as 1:1 electrolytes in acetone
solutions. Their IR spectra show bands arising from the
diphosphine and the triflate anion and ν(CdN) vibrations at
1513 (w) and 1590 (m) cm-1
.
The 1H NMR spectra present signals similar to those observed
for the previous compounds, but now the dppf:ligand ratio is
1:1. The 31P{1H} spectra show only a singlet for the two

Substitution Reactions of [Au2Cl2(µ-dppf)]
Table 4. NMR Data for Complexes 2-11
Inorganic Chemistry, Vol. 36, No. 23, 1997 5209
1H
31P
complex
no.
δ(dppf)
δ(SR)
δ(L)
δ(dppf)
δ(L)
[Au2Br2(µ-dppf)]
2
4.29 (m)
4.73 (m)
4.33 (m)
4.69 (m)
4.34 (m)
4.80 (m)
27.5 (s)
[Au2I2(µ-dppf)]
3
4
34.42 (s)
32.3 (s)
[Au2(Spy)2(µ-dppf)]
6.84 (d)
7.29 (t)
8.23 (d)
1.35 (t)
3.94 (q)
7.43 (d)
7.69 (“t”)
8.45 (“t”)
1.57 (t)
4.07 (q)
7.39 (d)
7.74 (t)
1.44 (t)
4.05 (q)
7-9 (m)
[Au2(S2CNEt2)2(µ-dppf)]
5
6
4.30 (m)
4.82 (m)
4.27 (m)
4.57 (m)
27.7 (s)
28.0 (s)
[Au4(µ-Spy)2(µ-dppf)(PPh2Me)2}](OTf)2
2.02 (s)
1.45 (d)
17.9 (s)
[Au4(µ-S2CNEt2)(µ-dppf)(PPh2Me)2](ClO4)2
[Au2(µ-Spy)(µ-dppf)]OTf
7
8
4.40 (m)
4.47 (m)
4.28 (m)
4.56 (m)
4.36 (m)
4.45 (m)
4.18 (m)
4.67 (m)
4.28 (m)
4.52 (m)
32.1 (s)
21.2 (s)
32.9 (s)
27.4 (br)a
32.9 (s)
[Au2(µ-S2CNEt2)(µ-dppf)]OTf
9
[Au6(µ-Spy)2(µ-dppf)(PPh2Me)4](OTf)4
[Au6(µ-S2CNEt2)2(µ-dppf)(PPh3)4](OTf)4
10
11
1.96 (s)
27.1 (s)
22.8 (s)a
34.6 (s)
36.8 (s)b
17.2 (s)
18.9 (s), 12.6 (s)a
31.0 (m)
1.63 (t)
4.07 (q)
32.8 (s), 31.1 (s)b
a Measured at -85 °C in CD2Cl2. b Measured at -80 °C in (CD3)2CO.
phosphorus atoms. The 31P{1H} spectrum of 8 has been
recorded at low temperature (at -55 °C in CDCl3 and at -85
°C in CD2Cl2) and a broadening of the signal is observed (at
-85 °C, ∆ ) 726 Hz) but the signal does not split into two
singlets as expected. Fluxional processes involving the 2-py-
ridinethiolate ligand (through intermediates in which the ligand
acts as an S-donor bridge) have already been proposed for
rhodium and gold complexes.7e,11
The positive-ion fast-atom bombardment mass spectra show
the cation molecular peaks at m/z ) 1058 (8, 100%) and 1096
(9, 100%). There also appears with high abundance the
fragment [Au(dppf)]+ at m/z ) 751.
The chemical shifts of complexes 6 and 10 can be compared,
and a high-field displacement is observed in the resonances of
complex 10 as a consequence of the further coordination of a
(phosphine)gold unit. This upfield shift was previously ob-
served by us in the complexes [S(AuPR3)n](n-2)+ (n ) 2-6).12
These data lead us to propose the structure shown in Scheme
1; this type of structure has been found for dithiolate complexes
such as [Au3(3,4-S2C6H3Me)(PPh3)3]ClO4,13 [Au3{S2(CH2)2}-
(PPh3)3]BF4,14or[(Ph3PAu)SCH2CHS(AuPPh3)CH2S(AuPPh3)2]-
BF4.15
In an attempt to structurally characterize complex 10 or 11,
we obtained single crystals by slow diffusion of hexane into a
dichloromethane solution of complex 10. However, the con-
sequent X-ray diffraction studies revealed the compound [Au3-
(µ3-Spy)(µ-dppf)(PPh2Me)](OTf)2, 12 (as a tetrachloroethane
solvate) (Figure 3), presumably having arisen by decomposition
of complex 10. We tried to synthesize complex 12 deliberately
by reaction of [Au2(µ-Spy)(µ-dppf)]OTf (8) with [Au(OTf)PPh2-
Me] in dichloromethane, but a mixture of complexes was
obtained.
We have also studied further reactions of 4 and 5 with [Au-
(OTf)PR3] (molar ratio 1:4) with the aim of incorporating more
+
AuPR3 fragments at the thiolate or dithiocarbamate ligands.
The complexes [Au6(µ-SR)2(µ-dppf)(PR3)4](OTf)4 (SR ) Spy,
PR3 ) PPh2Me (10); SR ) S2CNEt2, PR3 ) PPh3 (11)) have
been isolated as yellow solids, stable to air and moisture. Their
conductivities measured in acetone are in agreement with the
proposed formulas, 315 (10) and 356 (11) Ω-1 cm2 mol-1
.
Although there are not many data for conductivities of highly
charged compounds, the values obtained seem appropriate for
tetracationic species; we obtained similar values for the [S(Au-
PR3)6]4+ species.12
The H NMR spectra of 10 and 11 are similar to those of
complexes 6 and 7; the most significant differences are seen in
Selected bond lengths and angles are collected in Table 3.
The cation of 12 consists of two gold atoms bridged by two
different ligands, dppf and 2-pyridinethiolate; the third gold atom
is bonded to a tertiary phosphine and to the sulfur atom of the
thiolate ligand. In this manner Spy- acts as a triply bridging
ligand.
1
the integral ratio for the protons, which is consistent with the
The gold atoms have geometries slightly distorted from
linearity with angles P(1)-Au(1)-S 177.9(2), N(91)-Au(2)-
P(2) 173.3(5), and P(3)-Au(3)-S(1) 176.8(2)°; the latter
deviations from 180° may be associated with the imposed
restrictions of the 2-pyridinethiolate ligand and the weak gold-
gold interactions, Au(1)-Au(2) 3.2105(13) and Au(1)-Au(3)
3.0985(12) Å. The gold-gold distance in the ring is consider-
ably longer than was found in the complex [Au2{µ-(CH2)2PPh2}-
(µ-Spy)] (2.8623(7) Å),7e which also has two different bridging
ligands. The Au-S distances, 2.341(4) and 2.337(6) Å, are as
+
coordination of four AuPR3 fragments. The 31P{1H} NMR
spectra at room temperature show in both cases two singlets in
a 1:2 ratio which should correspond to two phosphorus
environments, namely the phosphorus of dppf and that of the
tertiary phosphines. When the experiments are carried out at
low temperature, three singlets of an approximate 1:1:1 ratio
appear for complexes 10 and 11, which indicates that there are
+
three different phosphorus enviroments because the two AuPR3
fragments bonded to the same SR- ligand are not equivalent.
(11) Ciriano, M. A.; Viguri, F.; Pe´rez-Torrente, J. J.; Lahoz, F. J.; Oro, L.
A.; Tiripicchio-Camellini, A.; Tiripicchio-Camellini, M. J. Chem. Soc.,
Dalton Trans. 1989, 25.
(12) Canales, F.; Gimeno, M. C.; Laguna, A.; Villacampa, M. D. Inorg.
Chim. Acta 1996, 244, 95.
(13) Gimeno, M. C.; Jones, P. G.; Laguna, A.; Laguna, M.; Terroba, R.
Inorg. Chem. 1994, 33, 3932.
(14) Sladek, A.; Schmidbaur, H. Chem. Ber. 1995, 128, 907.
(15) Sladek, A.; Schmidbaur, H. Inorg. Chem. 1996, 35, 3268.

5210 Inorganic Chemistry, Vol. 36, No. 23, 1997
Canales et al.
Table 5. Details of Data Collection and Structure Refinement for Complexes 1, 3, and 12
1‚CH2Cl2
3‚2CH2Cl2
12‚C2H4Cl2
empirical formula
crystal habit
crystal size/mm
crystal system
space group
a/Å
C36H32AuCl6FeP2
colorless prism
0.60 × 0.50 × 0.50
triclinic
P1h
8.671(2)
9.867(2)
12.359(3)
81.82(2)
74.45(3)
70.56(2)
959.0(4)
1
C36H32Au2Cl4FeI2P2
yellow needle
0.70 × 0.20 × 0.04
triclinic
P1h
11.955(3)
13.472(3)
14.596(2)
85.85(2)
70.16(2)
66.04(2)
2015.1(7)
2
C56H49Au3Cl2F6FeNO6P3S3
colorless prism
0.40 × 0.40 × 0.20
monoclinic
P21/n
13.831(3)
b/Å
c/Å
14.181(3)
31.059(7)
R/deg
â/deg
102.17(2)
γ/deg
V/Å3
5955(2)
4
2.067
1852.70
3536
Z
Dc/g cm-3
M
2.059
1189.04
564
2.261
1371.94
1272
F(000)
T/°C
-100
-100
-100
2θmax/deg
µ(Μo KR)/cm-1
transm
no. of reflns measd
no. of unique reflns
Rint
50
50
50
85.31
0.553-1.0
4365
3342
0.021
0.026
0.068
3340
215
154
1.022
95.20
0.035-0.839
7067
6796
0.241
0.111
0.312
6776
178
0
1.065
3.048
79.51
0.340-0.968
11278
10472
0.027
0.067
0.188
10460
281
Ra (F > 4σ(F))
Rwb (F2, all reflns)
no. of reflns used
no. of parameters
no. of restraints
Sc
46
0.865
1.585
max ∆F/e Å-3
1.503
2
2
2
2
a R(F) ) ∑||Fo| - |Fc||/∑|Fo|. b Rw(F2) ) [∑[w(Fo - Fc2)2]/∑[w(Fo )2]}0.5; w-1 ) σ2(Fo ) + (aP)2 + bP, where P ) (Fo + 2Fc2)/3 and a and
b are constants adjusted by the program. c S ) {∑[w(Fo - Fc2)2]/(n - p)]0.5, where n is the number of data and p the number of parameters.
2
Complex 3: yield 60%; ΛM 7 Ω-1 cm2 mol-1
. Anal. Calc for
expected longer than those in the latter compound since in 10
the sulfur atom is bonded to two metals. The Au-N bond
length of 2.065(14) Å is similar to that found in [Au2{µ-(CH2)2-
PPh2}(µ-Spy)] (2.060(10) Å).
The cyclopentadienyl rings adopt a conformation approxi-
mately midway between staggered and eclipsed.
C34H28Au2FeI2P2: C, 33.97; H, 2.35. Found: C, 34.24; H, 2.35.
[Au2(Spy)2(µ-dppf)], 4. To a solution of [Au2Cl2(µ-dppf)] (0.102
g, 0.1 mmol) in dichloromethane (25 mL) were added HSpy (0.022 g,
0.2 mmol) and Na2CO3 (0.4 g). The mixture was stirred for 3 h and
then filtered to remove sodium carbonate. The solution was concen-
trated to ca. 5 mL, and addition of diethyl ether (15 mL) gave complex
4 as a yellow solid: yield 86%; ΛM 0.6 Ω-1 cm2 mol-1. Anal. Calc
for C44H36Au2FeN2P2S2: C, 45.22; H, 3.10; N, 2.39; S, 5.48. Found:
C, 44.52; H, 2.83; N, 2.18; S, 4.84.
Experimental Section
Instrumentation. Infrared spectra were recorded in the range
4000-200 cm-1 on a Perkin-Elmer 883 spectrophotometer using Nujol
mulls between polyethylene sheets. Conductivities were measured in
ca. 5 × 10-4 mol dm-3 solutions with a Philips 9509 conductometer.
C and H analyses were carried out with a Perkin-Elmer 2400
microanalyzer. Mass spectra were recorded on a VG Autospec, with
the FAB technique, using nitrobenzyl alcohol as matrix. NMR spectra
were recorded on a Varian Unity 300 spectrometer and a Bruker ARX
300 spectrometer in CDCl3. Chemical shifts are cited relative to SiMe4
(1H, external) and 85% H3PO4 (31P, external) (Table 4).
Materials. The starting materials [Au2Cl2(µ-dppf)]4a and [AuCl-
(PR3)]16 were prepared by published procedures. [Au(OTf)(PR3)] or
[Au(OClO3)PR3] was obtained from [AuCl(PR3)] by reaction with
AgOTf or AgClO4, respectively.
Safety Note! Perchlorate salts of metal complexes with organic
ligands are potentially explosive. Only small amounts of materials
should be prepared, and these should be handled with great caution.
Syntheses. [Au2X2(µ-dppf)] (X ) Br (2), I (3)). To a solution of
[Au2Cl2(µ-dppf)] (0.102 g, 0.1 mmol) in acetone (20 mL) was added
KX (0.024 g, X ) Br; 0.034 g, X ) I; 0.2 mmol). The mixture was
stirred for 1 day; then the solvent was evaporated to dryness and the
product redissolved in dichloromethane (20 mL) in order to eliminate
the insoluble KX. The solution was concentrated to ca. 5 mL, and
addition of diethyl ether (15 mL) gave complex 2 or 3 as an orange
solid. Complex 2: yield 84%; ΛM 1 Ω-1 cm2 mol-1. Anal. Calc for
C34H28Au2Br2FeP2: C, 36.85; H, 2.55. Found: C, 37.15; H, 2.33.
[Au2(S2CNEt2)2(µ-dppf)], 5. To a solution of [Au2Cl2(µ-dppf)]
(0.102 g, 0.1 mmol) in a dichloromethane-water mixture (20:5 mL)
was added NaS2CNEt2‚3H2O (0.045 g, 0.2 mmol). The mixture was
stirred for 2 h, and then the organic phase was separated from the
mixture. The solution was concentrated to ca. 5 mL, and addition of
diethyl ether (15 mL) gave complex 5 as a yellow solid: yield 99%;
Λ
M 0.8 Ω-1 cm2 mol-1. Anal. Calc for C44H38Au2FeN2P2S4: C, 42.45;
H, 3.89; N, 2.26; S, 10.3. Found: C, 42.58; H, 3.40; N, 2.26; S, 9.90.
[Au4(µ-SR)2(µ-dppf)(PPh2Me)2]X2 (SR ) Spy (6), X ) OTf; SR
) S2CNEt2 (7), X ) ClO4). To a dichloromethane solution (15 mL)
of complex 4 (0.117 g, 0.1 mmol) or 5 (0.124 g, 0.1 mmol) was added
a freshly prepared solution of [Au(OTf)PPh2Me] or [Au(OClO3)PPh2-
Me] (0.2 mmol, 20 mL). The mixture was stirred for 30 min, and
then the solvent was evaporated under vacuum to ca. 5 mL; addition
of diethyl ether (15 mL) afforded complex 6 or 7 as a yellow solid.
Complex 6: yield 96%; ΛM 186 Ω-1 cm2 mol-1
. Anal. Calc for
C72H62Au4F6FeN2O6P4S4: C, 38.3; H, 2.76; N, 1.23; S, 5.66. Found:
C, 38.6; H, 2.86; N, 1.36; S, 4.80. Complex 7: yield 75%; ΛM 204
Ω-1 cm2 mol-1. Anal. Calc for C70H64Au4Cl2FeN2O8P4S4: C, 37.6;
H, 3.33; N, 1.25; S, 5.73. Found: C, 38.4; H, 2.81; N, 1.20; S, 5.29.
[Au2(µ-SR)(µ-dppf)]OTf (SR ) Spy (8), S2CNEt2 (9)). To a
dichloromethane solution (20 mL) of complex 4 (0.117 g, 0.1 mmol)
or 5 (0.124 g, 0.1 mmol) was added AgOTf (0.026 g, 0.1 mmol). The
mixture was stirred for 30 min, and then the [Ag(SR)]n formed was
filtered off. The solution was concentrated under vacuum to ca. 5 mL;
addition of diethyl ether (15 mL) afforded complex 8 or 9 as a yellow
solid. Complex 8: yield 88%; ΛM 121.5 Ω-1 cm2 mol-1. Anal. Calc
for C40H32Au2F3FeNO3P2S2: C, 39.8; H, 2.65; N, 1.16; S, 5.31.
(16) Uso´n, R.; Laguna, A. Inorg. Synth. 1982, 21, 71.

Substitution Reactions of [Au2Cl2(µ-dppf)]
Inorganic Chemistry, Vol. 36, No. 23, 1997 5211
Found: C, 39.7; H, 2.70; N, 1.27; S, 3.01. Complex 9: yield 96%;
ΛM 100.3 Ω-1 cm2 mol-1. Anal. Calc for C39H38Au2F3FeN2O3P2S4:
C, 37.6; H, 3.07; N, 1.12; S, 12.8. Found: C, 37.5; H, 2.64; N, 1.82;
S, 10.1.
[Au6(µ-SR)2(µ-dppf)(PR3)4](OTf)4 (SR ) Spy (10), PR3 ) PPh2Me;
SR ) S2CNEt2 (11), PR3 ) PPh3). To a dichloromethane solution
(15 mL) of complex 4 (0.117 g, 0.1 mmol) or 5 (0.124 g, 0.1 mmol)
was added a freshly prepared solution of [Au(OTf)PPh2Me] or [Au-
(OTf)PPh3] (0.4 mmol, 20 mL). The mixture was stirred for 30 min,
and then the solvent was evaporated in vacuum to ca. 5 mL; addition
of diethyl ether (15 mL) afforded complex 10 or 11 as a yellow solid.
Complex 10: yield 76%; ΛM 315 Ω-1 cm2 mol-1. Anal. Calc for
constants were refined from setting angles of ca. 60 reflections in the
2θ range 10-25°. Absorption corrections were applied on the basis
of Ψ scans. Structures were solved by the heavy-atom method and
refined on F2 using the program SHELXL-93.17 All non-hydrogen
atoms were refined anisotropically. Hydrogen atoms were included
using a riding model. Further details are given in Table 5. Special
problems for 12: The triflate ions are badly resolved although
recognizable; the dichloroethane is severely disordered and was refined
solely as three chlorine sites, two of which are half-occupied. For
complex 1 a system of restraints on light-atom displacement-factor
components and local ring symmetry was used.
Acknowledgment. We thank the Direccio´n General de
Investigacio´n Cient´ıfica y Te´cnica (Grant No. PB94-0079) and
the Fonds der Chemischen Industrie for financial support.
C100H88Au6F12FeN2O12P6S6: C, 35.8; H, 2.64; N, 0.83; S, 5.73.
Found: C, 36.14; H, 2.65; N, 0.86; S, 5.65. Complex 11: yield 96%;
ΛM 356 Ω-1 cm2 mol-1. Anal. Calc for C120H98Au6F12FeN2O12P6S8:
C, 39.2; H, 2.94; N, 0.76; S, 6.97. Found: C, 39.6; H, 3.20; N, 0.92;
S, 7.54.
Supporting Information Available: Three X-ray crystallographic
files, in CIF format, are available on the Internet only. Access
information is given on any current masthead page.
Crystal Structure Determinations
IC9704445
The crystals were mounted in inert oil on glass fibers and transferred
to the cold gas stream of a Siemens P4 diffractometer equipped with
an LT-2 low-temperature device. Data were collected using mono-
chromated Mo KR radiation (λ ) 0.710 73 Å). Scan type: ω. Cell
(17) Sheldrick, G. M. SHELXL-93: Program for Crystal Structure Refine-
ment. University of Go¨ttingen, Germany, 1993.