Synthesis, structure and redox behaviour of gold and silver complexes with 3-ferrocenylpyridine

Article abstract of DOI:10.1016/S0022-328X(99)00547-1

3-Ferrocenylpyridine (Fcpy) reacts with gold(I) derivatives to afford neutral, [AuR(Fcpy)] (R=Cl, C₆F₅), or cationic complexes, [Au(Fcpy)(PPh₃)]OTf. Reaction with [Au(C₆F₅)₂(OEt₂

Full text of DOI:10.1016/S0022-328X(99)00547-1

www.elsevier.nl/locate/jorganchem
Journal of Organometallic Chemistry 592 (1999) 258–264
Synthesis, structure and redox behaviour of gold and silver
complexes with 3-ferrocenylpyridine
Eva M. Barranco a, Olga Crespo a, M. Concepcio´n Gimeno a, Peter G. Jones b,
Antonio Laguna a,*, M. Dolores Villacampa a
a Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n, Uni6ersidad de Zaragoza-CSIC, E-50009 Zaragoza, Spain
b Institut fu¨r Anorganische und Analytische Chemie der Technischen Uni6ersita¨t, Postfach 3329, D-38023 Braunschweig, Germany
Received 20 August 1999; accepted 20 September 1999
Abstract
3-Ferrocenylpyridine (Fcpy) reacts with gold(I) derivatives to afford neutral, [AuR(Fcpy)] (R=Cl, C6F5), or cationic
complexes, [Au(Fcpy)(PPh3)]OTf. Reaction with [Au(C6F5)2(OEt2)2]ClO4 or [Au(C6F5)3(OEt2)] gives the gold(III) complexes
[Au(C6F5)2(Fcpy)2]ClO4 or [Au(C6F5)3(Fcpy)], respectively. The silver derivatives [Ag(Fcpy)(PPh3)]OTf and [Ag(OTf)(Fcpy)2]
have also been synthesised. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Gold; Silver; Ferrocene; Ferrocenylpyridine; Redox behaviour
Fcpy). Cyclic voltammetry studies have been performed
and show one electron reversible oxidation based on
the ferrocene moiety; the silver compounds show one
further irreversible oxidation for the silver centre.
1. Introduction
In the last few years the chemistry of ferrocene and
the design of new compounds containing the ferrocene
unit has received much attention, associated with the
utility of such compounds in many fields such as or-
ganic synthesis, homogeneous catalysis, material chem-
istry, and production of fine chemicals [1–4].
Numerous derivatives have been described in which the
ferrocene unit is bound to a fragment containing one or
more donor atoms. Studies of these ligands are impor-
tant because the complexes thus obtained may have
interesting redox properties or unusual structures.
The ferrocenylpyridines were synthesised some years
ago [5,6] but their coordination properties have not
been intensively studied. As far as we are aware, only
some rhenium complexes with the 4-Fcpy [7] and one
platinum derivative with the 3-Fcpy [6] ligand have
been described. As part of our studies of ferrocene
derivatives as ligands [8–15], we report here on the
synthesis of several gold and silver complexes with the
3-ferrocenylpyridine ligand (henceforth abbreviated as
2. Results and discussion
2.1. Synthesis
Treatment of equimolecular amounts of [AuR(tht)]
(R=Cl or C6F5, tht=tetrahydrothiophene) with 3-fer-
rocenylpyridine in dichloromethane affords the neutral
complexes [AuR(Fcpy)] [R=Cl (1), C6F5 (2)] (Scheme
1). Compounds 1 and 2 are moisture- and air-stable red
solids that behave as non-conductors in acetone solu-
tion. In the IR spectrum of 1 the bands arising from the
ferrocene and pyridine moiety can be observed, and
additionally a new band at 358 (s) cm−1 from the
vibration w(AuꢀCl); the IR spectrum of complex 2
shows strong absorptions at 1505 (s), 955 (s) and 790 (s)
cm−1 for the pentafluorophenyl unit. In the positive-
ion liquid secondary ion mass spectrum (LSIMS) of 1
the molecular peak does not appear but the fragment
arising from the loss of one chlorine is present at
m/z=460 (19%); the molecular peak of complex 2
appears at m/z=627 (5%).
* Corresponding author. Tel.: +34-976-761185; fax:+34-976-
761187.
E-mail address: alaguna@posta.unizar.es (A. Laguna)
0022-328X/99/$ - see front matter © 1999 Elsevier Science S.A. All rights reserved.
PII: S0022-328X(99)00547-1

E.M. Barranco et al. / Journal of Organometallic Chemistry 592 (1999) 258–264
259
1
show bands at 1512 (s), 1506 (s), 968 (s), 805 (m) and
786 (m) for the pentafluorophenyl groups, at 1100 (vs,
br) and 619 (s) cm−1 for the perchlorate anion (com-
plex 5) and at 1507 (s), 969 (s), 820 (m) and 792 (m)
(complex 6) cm−1 also for the pentafluorophenyl
groups. In the LSIMS+ spectra the cation molecular
peak appears for complex 5 at m/z=1057 (20%) and
the molecular peak at m/z=961 (100%) is present for
complex 6.
The H-NMR spectra show the three resonances for
the ferrocene protons in a ratio 2:2:5 for a- and b-pro-
tons of the substituted Cp ring and for the unsubsti-
tuted Cp ring, respectively. The pyridine protons
appear as singlet (H2), doublet (H4), doublet of dou-
blets (H5) and doublet (H6). The 19F-NMR spectrum of
2 presents two multiplets for the ortho and meta and a
triplet for the para fluorine.
The reaction of Fcpy with [M(OTf)(PPh3)] (M=Au,
Ag) gives the cationic complexes [M(Fcpy)(PPh3)]OTf
[M=Au (3), Ag (4)]. Acetone solutions of complexes 3
and 4 behave as 1:1 electrolytes. The solid IR spectra
present bands at 1265 (vs, br), 1223 (s), 1150 (s) and
1023 (s) cm−1, arising from the trifluoromethanesul-
fonate. In the LSIMS+ spectra the cation molecular
peaks appear at m/z=722 (100%) and 633 (62%),
1
The H-NMR spectra for complexes 5 and 6 show
one singlet for the unsubstituted Cp ring and two
multiplets for the a- and b-protons of the substituted
Cp rings; also the four resonances for the protons of
the pyridine group appear. The 19F-NMR spectra of 5
presents three resonances for the equivalent pen-
tafluorophenyl rings; complex 6 presents six signals in a
ratio 2:1 for the mutually trans pentafluorophenyl rings
and for the cis pentafluorophenyl ring, respectively.
The treatment of AgOTf with two equivalents of
ferrocenylpyridine in diethyl ether affords the complex
[Ag(OTf)(Fcpy)2] (7) in high yield. Complex 7 is an air-
and moisture-stable red solid that presents a low con-
ductivity value in acetone for a 1:1 electrolyte, perhaps
because of the weak coordination of the triflate anion.
The IR spectrum shows the band for the trifl-
uoromethanesulfonate ion coordinated to the silver cen-
tre at 1265 (vs, br), 1222 (s), 1150 (s) and 1104 (s)
cm−1. In the LSIMS+ spectrum the cation appears at
m/z=633 as the most intense peak; the fragment aris-
ing from the loss of one Fcpy ligand is also present at
m/z=370 (76%).
1
respectively. The H-NMR spectra show the three reso-
nances for the ferrocene moiety and the four resonances
for the pyridine protons. The 31P-NMR spectrum of 3
consists of a singlet whereas that of 4 (at −55°C)
consist of two doublets by coupling of the phosphorus
atom with the two silver nuclei, 107Ag and 109Ag.
Gold(III) derivatives with the ferrocenylpyridine lig-
and can be achieved by reaction of Fcpy with
[Au(C6F5)2(OEt2)2]ClO4 (molar ratio 2:1) leading to
[Au(C6F5)2(FcPy)2]ClO4 (5) or with [Au(C6F5)3(OEt2)]
(molar
ratio
1:1)
affording
the
complex
[Au(C6F5)3(Fcpy)] (6). Complexes 5 and 6 are red air-
and moisture-stable solids; 5 is a 1:1 electrolyte and 6 is
non conducting in acetone solution. Their IR spectra
Scheme 1. (i) [AuCl(tht)] or [Au(C6F5)(tht)], (ii) [Au(OTf)(PPh3)] or [Ag(OTf)(PPh3)], (iii) [Au(C6F5)2(OEt2)2]ClO4, (iv) [Au(C6F5)3(OEt2)], (v) 1/2
Ag(OTf).

260
E.M. Barranco et al. / Journal of Organometallic Chemistry 592 (1999) 258–264
Table 1
moiety in a ratio 2:2:5 and four resonances for the
pyridine unit in a 1:1:1:1 ratio.
a
,
Selected bond lengths (A) and angles (°) for 2
AuꢀC(31)
AuꢀN
AuꢀAuc1
2.00(2)
2.124(15)
3.301(2)
C(1)ꢀN
C(5)ꢀN
1.40(2)
1.27(2)
2.2. Molecular structures
The structures of the following complexes have been
established by X-ray diffraction: the gold(I) derivatives
[Au(C6F5)(Fcpy)] (2) and [Au(Fcpy)(PPh3)]OTf (3) and
the gold(III) compounds [Au(C6F5)2(Fcpy)2]ClO4 (5)
and [Au(C6F5)3(Fcpy)] (6).
Complex 2 crystallises in the monoclinic system and
complex 3 in the orthorhombic system with four
molecules of dichloromethane and two independent
molecules in the asymmetric unit; these two molecules
differ slightly in angles and bond distances. Selected
bond lengths and angles of 2 and 3 are shown in Tables
1 and 2, respectively. In the lattice of compound 2 the
molecules are associated into pairs across inversion
centres via a weak intermolecular Au···Au interaction
C(31)ꢀAuꢀN
176.3(6)
90.3(4)
93.4(4)
C(5)ꢀNꢀAu
C(1)ꢀNꢀAu
C(36)ꢀC(31)ꢀAu
122.6(13)
117.2(12)
123.8(10)
C(31)ꢀAuꢀAuc1
NꢀAuꢀAuc1
a Symmetry transformations used to generate equivalent atoms:
c1 −x, −y, −z.
Table 2
,
Selected bond lengths (A) and angles (°) for 3
Au(1)ꢀN(1)
Au(1)ꢀP(1)
Au(2)ꢀN(2)
Au(2)ꢀP(2)
P(1)ꢀC(41)
P(1)ꢀC(61)
P(1)ꢀC(51)
2.070(9)
2.228(3)
2.065(10)
2.233(3)
1.804(11)
1.825(13)
1.849(13)
P(2)ꢀC(71)
P(2)ꢀC(91)
P(2)ꢀC(81)
C(14)ꢀN(1)
N(1)ꢀC(15)
C(29)ꢀN(2)
N(2)ꢀC(30)
1.790(13)
1.795(12)
1.825(13)
1.343(15)
1.370(15)
1.35(2)
1.294(14)
,
of 3.301(2) A (Fig. 1). However, the cations of com-
N(1)ꢀAu(1)ꢀP(1)
N(2)ꢀAu(2)ꢀP(2)
C(41)ꢀP(1)ꢀAu(1) 112.6(3)
C(61)ꢀP(1)ꢀAu(1) 108.8(4)
172.3(3)
175.6(3)
C(51)ꢀP(1)ꢀAu(1)
C(71)ꢀP(2)ꢀAu(2)
C(91)ꢀP(2)ꢀAu(2)
C(81)ꢀP(2)ꢀAu(2)
115.8(4)
109.8(4)
115.9(4)
112.0(4)
pound 3 (Fig. 2) are not associated in the crystal,
presumably because steric effects of the bulky Ph3P
groups prevent the intimate approach required for
metal–metal contacts.
The gold atoms, in both derivatives, have geometries
slightly distorted from linearity with angles
C(31)ꢀAuꢀN 176.3(6)° for 2 and N(1)ꢀAu(1)ꢀP(1)
172.3(3) and N(2)ꢀAu(2)ꢀP(2) 175.6(3)° for 3. Although
,
the AuꢀN distance in 2, 2.124(15) A, is longer than the
,
AuꢀN distances in 3, 2.065(10) and 2.070(9) A, the
differences may not be highly significant. These values
are in line with those found in related two-coordinated
gold(I) compounds with an AuꢀN(pyridine) or similar
bond, such as [Au(PPh3)(dmpy)]ClO4 (dmpy=2,6-
,
dimethylpyridine) [16] (2.091(13) A) or [(AuPPh3)py-
{SCH2C(O)Ph}-2]ClO4 (two independent molecules
Fig. 1. The structure of complex 2 in the crystal showing the atom
numbering scheme. Radii are arbitrary. H atoms are omitted for
clarity.
,
with 2.082(4) and 2.092(4) A) [17].
,
The AuꢀC distance in 2 (2.00(2) A) is similar to that
observed in the complex [Au(C6F5)(Ph2C=NꢀN=
,
CPh2)] (1.992(9) A) [18], in which an NꢀAuꢀC unit is
present, or to those found in other pentafluorophenyl-
gold(I) derivatives such as [Au2(C6F5)2(m-dppm)]
,
(2.058(12) and 2.063(12) A) [19] (dppm=bis-
(diphenylphosphino)methane). AuꢀP bond lengths in 3
,
(2.228(3) and 2.233(3) A) are normal and compare well
with those found in the above-mentioned related
,
gold(I) complexes [Au(PPh3)(dmpy)]ClO4 (2.233(4) A)
[16] and [(AuPPh3)py{SCH2C(O)Ph}-2]ClO4
,
(2.2359(13), 2.2388(13) A) [17].
Fig. 2. The cation of one of the two independent formula units of
complex 3 in the crystal. Radii are arbitrary. H atoms are omitted for
clarity.
The expected square planar geometry for gold in
complexes 5 and 6 was confirmed (Figs. 3 and 4, Tables
3 and 4). Mean deviations of the planes formed by the
four donor atoms and the gold centre are 0.0034, N1,
In the 1H-NMR spectrum both ferrocenylpyridine
groups are equivalent and the typical pattern for the
ligand appears, with three resonances for the ferrocene
,
N2, C31, C41, Au (5) and 0.2899 A, N11, C21, C31,
C41, Au (6). These structures are, as far as we know,
the first with gold(III) derivatives bonded both to pen-

E.M. Barranco et al. / Journal of Organometallic Chemistry 592 (1999) 258–264
261
tafluorophenyl rings and a nitrogen donor atom. The
AuꢀC distances to mutually trans pentafluorophenyl
,
groups in compound 6 are 2.067(3), 2.068(3) A. These
distances lie in the same range as those found in other
tris(pentafluorophenyl)gold(III) derivatives such as
,
[Au(C6F5)3(S2SꢀPEt3)] (2.067(4), 2.076(4) A) [20]. The
trans influence of the pentafluorophenyl ligand is
reflected in the different AuꢀC distances found for
carbon atoms trans to the nitrogen atom of the ferro-
,
cenyl ligand: C(21)ꢀAu in 6 (2.017(3) A) or C(31)ꢀAu,
,
C(41)ꢀAu in 5 (2.011(9), 2.015(9) A, respectively).
AuꢀN distances in both complexes (2.076(7), 2.089(7)
,
,
A, 5; 2.101(3) A, 6) are longer than those found
in other gold(III) complexes in which an AuꢀN(pyri-
dine) or related bond is present, e.g. [Au{dpk-(OH)2}-
Cl2]Cl (dpk=di-2-pyridylmethanediol-N,N%) (2.039(5),
Fig. 3. Perspective view of the cation of complex 5 in the crystal. H
atoms are omitted for clarity.
,
,
2.042(5) A) [21], or in [AuCl3(C6H7ꢀNO)] (2.021(9) A)
[22], corresponding to a higher trans influence of the
pentafluorophenyl ligand than of the chlorine ligand.
The only other reported compound containing this
ligand, [Pt(Fcpy)2Cl2], displays a similar geometry [6] to
that of complex 5, with the platinum centre showing a
square-planar stereochemistry, bonded to two carbon
and two nitrogen atoms.
Compounds 3 and 5 display several short and reason-
ably linear CꢀH···O contacts that might be interpreted
,
as hydrogen bonds. For 3 the shortest (H···OB2.5 A)
,
are C104ꢀH10E···O3 [H···O 2.11 A, CꢀH···O 151°];
,
,
C102ꢀH10B···O6 [2.34 A, 152°]; C56ꢀH56···O2 [2.41 A,
,
150°] and C29ꢀH29···O1 [2.46 A, 174°] (H10E and
H10B are hydrogens of dichloromethane), and for 5
,
,
C15ꢀH15···O1 [2.20 A, 151°]; C25ꢀH25···O5 [2.42 A,
,
163°]; C65ꢀH65···O2 [2.42 A, 159°]; C11ꢀH11···O5 [2.43
,
,
A, 124°]; C23ꢀH23···O3 [2.46 A, 136°] and C13ꢀ
H13···O2 [2.49 A, 134°] (O5 is the ether oxygen).
Fig. 4. Molecular structure of complex 6 in the crystal. H atoms are
omitted for clarity.
,
Table 3
2.3. Electrochemistry
,
Selected bond lengths (A) and angles (°) for 5
The electrochemical behaviour of the gold and silver
complexes with the 3-ferrocenylpyridine ligand has been
studied by cyclic voltammetry at a platinum electrode
in CH2Cl2. The free ligand undergoes a reversible one
electron oxidation process, based on the ferrocene unit,
at a potential very close to that of free ferrocene. The
coordination of a gold(I) fragment produces a shift to
slightly higher potentials for the oxidation–reduction of
the ferrocene moiety. The silver(I) compounds, show, in
addition of the wave due to the ferrocene oxidation, a
more anodic irreversible wave that can be assigned to
the one electron oxidation of Ag+ to Ag2+. Complexes
5 and 7, which possess two ferrocenylpyridine units,
show a simultaneous oxidation of these units rather
than a two-step process, as was observed for the plat-
inum complex cis-[PtCl2(Fcpy)2] [7]. Table 5 sum-
marises the electrochemical data for these compounds.
AuꢀC(31)
AuꢀC(41)
AuꢀN(1)
AuꢀN(2)
2.011(9)
2.015(9)
2.076(7)
2.089(7)
N(1)ꢀC(15)
N(1)ꢀC(11)
N(2)ꢀC(21)
N(2)ꢀC(25)
1.335(11)
1.373(11)
1.334(11)
1.340(11)
C(31)ꢀAuꢀC(41)
C(31)ꢀAuꢀN(1)
C(41)ꢀAuꢀN(1)
87.5(3)
176.4(3)
88.9(3)
C(31)ꢀAuꢀN(2)
C(41)ꢀAuꢀN(2)
N(1)ꢀAuꢀN(2)
90.1(3)
175.3(3)
93.5(3)
Table 4
,
Selected bond lengths (A) and angles (°) for 6
AuꢀC(21)
AuꢀC(41)
AuꢀC(31)
2.017(3)
2.067(3)
2.068(3)
AuꢀN(11)
N(11)ꢀC(12)
N(11)ꢀC(16)
2.101(3)
1.336(5)
1.348(4)
C(21)ꢀAuꢀC(41) 88.67(13)
C(21)ꢀAuꢀC(31) 89.51(13)
C(41)ꢀAuꢀC(31) 178.08(14)
C(21)ꢀAuꢀN(11)
C(41)ꢀAuꢀN(11)
C(31)ꢀAuꢀN(11)
179.85(14)
91.42(12)
90.41(12)

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E.M. Barranco et al. / Journal of Organometallic Chemistry 592 (1999) 258–264
Table 5
Anal. Calc. for C15H13AuClFeN: C, 36.36; H, 2.64; N,
Electrochemical data for complexes 1–7
2.73. Found: C, 35.90; H, 2.31; N, 2.73%. \M 36 V−1
1
cm2 mol−1. H-NMR, l: 4.09 (s, 5H, C5H5), 4.48 (m,
Compound
E1 (V)
E2 (V)
2H, C5H4), 4.65 (m, 2H, C5H4), 7.39 (m, 1H, py), 7.93
(m, 1H, py), 8.31 (m, 1H, py), 8.61 (s, 1H, py). Com-
plex 2: Yield 68%. Anal. Calc. for C21H13AuF5FeN: C,
40.22; H, 2.09; N, 2.23. Found: C, 39.75; H, 1.76; N,
2.14%. \M 4 V−1 cm2 mol−1. 1H-NMR, l: 4.20 (s, 5H,
C5H5), 4.53 (m, 2H, C5H4), 4.87 (m, 2H, C5H4), 7.45
(dd, 1H, py, H5, J(HH) 5.37 and 8.06 Hz), 7.97 (d, 1H,
py, H4, J(HH) 8.06 Hz), 8.39 (d, 1H, py, H6, J(HH)
5.37 Hz), 8.62 (s, 1H, py, H2). 19F-NMR, l: −116.5
(m, 2F, o-F), −159.7 (t, 1F, p-F, J(FF) 20.0 Hz),
−163.3 (m, 2F, m-F).
L Fcpy
1 [AuCl(Fcpy)]
0.48
0.52
0.62
0.53
0.76
0.56
0.69
0.51
2 [Au(C6F5)(Fcpy)]
3 [Au(Fcpy)PPh3]TfO
4 [Ag(Fcpy)PPh3]TfO
5 [Au(C6F5)2(Fcpy)2]ClO4
6 [Au(C6F5)3(Fcpy)]
7 [Ag(OTf)(Fcpy)2]
1.03
0.99
3. Experimental
IR spectra were recorded in the range 4000–200
cm−1 on a Perkin–Elmer 883 spectrophotometer using
Nujol mulls between polyethylene sheets. Conductivi-
ties were measured in ca. 5×10−4 mol dm−3 solutions
with a Philips 9509 conductimeter. C, H, N and S
analyses were carried out with a Perkin–Elmer 2400
microanalyzer. Mass spectra were recorded on a VG
Autospec, with the LSIMS 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 rela-
tive to SiMe4 (1H, external), CFCl3 (19F, external) and
85% H3PO4 (31P, external). Cyclic voltammetric experi-
ments were performed by employing an EG&G PARC
Model 273 potentiostat. A three-electrode system was
used, which consists of a platinum disk working elec-
trode, a platinum wire auxiliary electrode, and a satu-
rated calomel reference electrode. The measurements
were carried out in CH2Cl2 solutions with 0.1 M
Bu4NPF6 as a supporting electrolyte. Under the present
experimental conditions, the ferrocenium/ferrocene
couple was located at 0.47 V versus SCE. The starting
materials Fcpy [7], [AuCl(tht)] [23], [Au(C6F5)(tht)] [23],
[Au(C6F5)2(OEt2)2]ClO4 [24] and [Au(C6F5)3(OEt2)] [25]
were prepared by published procedures. [Au(OClO3)-
(PPh3)] was prepared from [AuCl(PPh3)] [26] and
AgClO4. [Au(OTf)(PPh3)] was prepared from [AuCl-
(PPh3)] by reaction with AgOTf in dichloromethane
and [Ag(OTf)(PPh3)] by reaction of AgOTf and PPh3 in
diethyl ether.
3.1.2. [M(Fcpy)(PPh3)]OTf [M=Au (3), Ag (4)]
To a solution of Fcpy (0.026 g, 0.1 mmol) in
dichloromethane (20 cm3) was added [Au(OTf)PPh3]
(0.061 g, 0.1 mmol) or [Ag(OTf)PPh3] (0.052 g, 0.1
mmol) and the mixture was stirred for 1 h. The solution
was concentrated to ca. 5 cm3 and addition of diethyl
ether (15 cm3) gave complexes 3 or 4 as red solids.
Complex
3:
Yield
63%.
Anal.
Calc.
for
C34H28AuF3FeNO3SP: C, 43.96; H, 3.16; N, 1.46; S,
3.32. Found: C, 44.09; H, 3.31; N, 1.32; S, 3.45%. \M
1
122 V−1 cm2 mol−1. H-NMR, l: 4.20 (s, 5H, C5H5),
4.45 (m, 2H, C5H4), 4.90 (m, 2H, C5H4), 7.3–7.8 (m,
2H, py+15H, Ph), 7.99 (d, 1H, py, H6, J(HH) 6.68
Hz), 8.58 (s, 1H, py, H2). 31P{1H}-NMR, 29.3 (s, 1P,
PPh3). Complex 4: Yield 70%. Anal. Calc. for
C34H28AgF3FeNO3SP: C, 52.20; H, 3.60; N, 1.79; S,
4.09. Found: C, 52.62; H, 3.59; N, 1.66; S, 3.88%. \M
1
110 V−1 cm2 mol−1. H-NMR, l: 4.20 (s, 5H, C5H5),
4.53 (m, 2H, C5H4), 4.87 (m, 2H, C5H4), 7.27 (dd, 1H,
py, H5, J(HH) 6.96 and 4.88 Hz), 7.3–7.6 (m, 15H,
Ph), 7.66 (d, 1H, py, H4, J(HH) 6.96 Hz), 8.35 (d, 1H,
py, H6, J(HH) 4.88 Hz), 8.75 (s, 1H, py, H2). 31P{1H}-
NMR, −55°C, 14.9 (2d, 1P, PPh3, J(109AgP) 753.9,
J(107AgP) 653.9 Hz).
3.1.3. [Au(C6F5)2(Fcpy)2]ClO4 (5)
To
a
diethyl ether solution (20 cm3) of
[Au(C6F5)2(OEt2)2]ClO4 (0.071 g, 0.1 mmol) was added
Fcpy (0.052 g, 0.2 mmol). The mixture was stirred for
30 min, during which time an orange precipitate ap-
peared. The solid was filtered off to give an orange
solid of complex 5. Yield 44%. Anal. Calc. for
C42H26AuClF10Fe2N2O4: C, 43.61; H, 2.26; N, 2.42.
Found: C, 43.05; H, 2.31; N, 2.30%. \M 110 V−1 cm2
3.1. Syntheses
3.1.1. [AuR(Fcpy)] [R=Cl (1), C6F5 (2)]
To a solution of Fcpy (0.026 g, 0.1 mmol) in
dichloromethane (20 cm3) was added [AuCl(tht)] (0.032
g, 0.1 mmol) or [Au(C6F5)(tht)] (0.045 g, 0.1 mmol) and
the mixture was stirred for 2 h. The solution was
concentrated to ca. 5 cm3 and addition of diethyl ether
(15 cm3) gave complex 1 or addition of hexane (15 cm3)
gave complex 2 as red solids. Complex 1: Yield 59%.
1
mol−1. H-NMR, l: 4.08 (s, 10H, C5H5), 4.60 (m, 4H,
C5H4), 4.95 (m, 4H, C5H4), 7.52 (m, 2H, py, H5), 7.87
(d, 2H, py, H4, J(HH) 3.27 Hz), 8.35 (d, 2H, py, H6,
J(HH) 2.06 Hz), 8.65 (s, 2H, py, H2). 19F-NMR, l:
−122.4 (m, 4F, o-F), −152.2 (t, 2F, p-F, J(FF) 20.0
Hz), −158.8 (m, 4F, m-F).

E.M. Barranco et al. / Journal of Organometallic Chemistry 592 (1999) 258–264
263
3.1.4. [Au(C6F5)3(Fcpy)] (6)
To
diethyl ether solution (20 cm3) of
filtered off to give a red solid of complex 7. Yield 85%.
Anal. Calc. for C31H26AgF3Fe2N2O3S: C, 47.64; H,
3.35; N, 3.58; S, 4.10. Found: C, 47.49; H, 3.43; N,
a
[Au(C6F5)3(OEt2)] (0.077 g, 0.1 mmol) was added Fcpy
(0.026 g, 0.1 mmol). The mixture was stirred for 30 min
and then the solution was evaporated to ca. 1 cm3;
addition of hexane afforded an orange solid of complex
6. Yield 80%. Anal. Calc. for C33H13AuF15FeN: C,
41.23; H, 1.36; N, 1.45. Found: C, 40.79; H, 1.02; N,
1.26%. \M 3 V−1 cm2 mol−1. 1H-NMR, l: 4.00 (s, 5H,
C5H5), 4.54 (m, 2H, C5H4), 4.67 (m, 2H, C5H4), 7.48
(m, 1H, py, H5), 7.92 (m, 1H, py, H4), 8.32 (m, 1H, py,
H6), 8.63 (s, 1H, py, H2). 19F-NMR, l: −122.7 (m,
2F, o-F), −125.0 (m, 4F, o-F), −156.5 (t, 2F, p-F,
J(FF) 19.9 Hz), −157.4 (t, 1F, p-F, J(FF) 20.0 Hz)
−161.2 (m, 4F, m-F), −162.3 (m, 2F, m-F).
1
3.61; S, 4.10/%. \M 76 V−1 cm2 mol−1. H-NMR, l:
4.28 (s, 10H, C5H5), 4.64 (m, 4H, C5H4), 4.98 (m, 4H,
C5H4), 7.25 (m, 2H, py, H5), 7.72 (m, 2H, py, 4H), 8.41
(m, 2H, py, H6), 8.65 (s, 2H, py, H2).
3.2. Crystal structure determinations
The crystals were mounted in inert oil on glass fibres
and transferred to the cold gas stream of a Siemens P4
diffractometer equipped with an LT-2 low temperature
attachment. Data were collected using monochromated
,
Mo–Ka radiation (u=0.71073 A). Scan type ꢀ. Ab-
sorption corrections were based on C-scans. The struc-
tures were solved by the heavy-atom method, and
refined on F2 using the programs SHELXL-93 (2, 3, 5) or
SHELXL-97 (6) [27]. Most non-hydrogen atoms were
refined anisotropically. Hydrogen atoms were included
using a riding model. Further details are given in Table
3.1.5. [Ag(OTf)(Fcpy)2] (7)
To a diethyl ether solution (20 cm3) of Ag(OTf)
(0.021 g, 0.1 mmol) was added Fcpy (0.052 g, 0.2
mmol). The mixture was stirred for 30 min, during
which time a red precipitate appeared. The solid was
Table 6
Details of data collection and structure refinement for complexes 2, 3, 5 and 6
Compound
2
3 2CH2Cl2
5 1.5CH2Cl2·(CH3CH2)2O
6
Chemical formula
Crystal habit
Crystal size (mm)
Crystal system
Space group
C21H13AuF5FeN
Orange plate
0.40×0.15×0.01
Monoclinic
P21/n
10.582(4)
7.395(2)
23.233(8)
–
93.35(2)
–
1814.9(10)
4
C36H32AuCl4F3FeNO3PS
C47H37AuCl3F10Fe2N2O5
C33H13AuF15FeN
Orange lath
0.55×0.20×0.10
Triclinic
Orange lath
0.80×0.20×0.10
Orthorhombic
Pca21
33.520(4)
9.6011(14)
23.811(2)
–
Red tablet
0.60×0.40×0.15
Monoclinic
C2/c
37.726(5)
13.916(3)
19.591(3)
–
104.97(2)
–
9936(3)
8
1.758
1314.80
5160
−100
50
0.376
(
P1
,
a (A)
10.1227(12)
12.8984(12)
13.2744(16)
66.351(8)
71.746(10)
88.884(8)
1496.5(3)
2
,
b (A)
,
c (A)
h (°)
i (°)
k (°)
–
–
3
,
U (A )
Z
7663(2)
8
1.805
1041.27
4080
−100
50
Dcalc (g cm−3
M
)
2.295
627.14
1184
−100
50
2.133
961.26
916
−100
50
F(000)
T (°C)
2qmax (°)
v(Mo–Ka) (cm−1
)
0.893
0.463
0.550
Transmission
No. of reflections measured
No. of unique reflections
1–0.705
3217
3185
0.1097
0.0653
0.1582
3185
1–0.562
11 374
11 363
0.1977
0.0494
0.1146
11 363
519
1–0.677
8793
8659
0.0419
0.0515
0.1357
8649
0.986–0.632
5149
5061
0.0180
0.0197
0.0432
5061
Rint
a
R
[F\4|(F)]
wR b(F2, all reflections)
No. of reflections used
No. of parameters
152
630
472
No. of restraints
35
0.881
2.608
101
0.945
1.681
541
0.865
1.524
133
0.971
0.411
c
S
−3
,
Max. Dz (e A
)
a R(F)=SꢀꢀFoꢀ−ꢀFcꢀꢀ/SꢀFoꢀ.
b wR(F2)=[S{w(F2o−F2c)2}/S{w(Fo2)2}]0.5; w−1=|2(Fo2)+(aP)2+bP, where P=[Fo2+2Fc2]/3 and a and b are constants adjusted by the
program.
c S=[S{w(F2o−F2c)2}/(n−p)]0.5, where n is the number of data and p the number of parameters.

264
E.M. Barranco et al. / Journal of Organometallic Chemistry 592 (1999) 258–264
[3] N.J. Long, Metalocenes, Blackwell, Oxford, 1998.
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Dalton Trans. (1995) 1473.
6. Special details of refinement: a system of restraints to
light-atom displacement-factor components and local
ring symmetry was used. Compound 2: C and N atoms
were refined isotropically. Compound 3: C atoms and
the second triflate ion, which is not well-resolved, were
refined isotropically. The high merging R value is not
meaningful, because very few equivalent reflections
were present, and these were at high 2q values. The
absolute structure (polar axis direction) was determined
by the method of Flack [28]; the x parameter refined to
−0.016(7). Compound 6: The Cp-ring C61–C65 is dis-
ordered over two positions with occupation factors
0.711, 0.289. The minor component was refined isotrop-
ically with idealised geometry.
[10] M.C. Gimeno, P.G. Jones, A. Laguna, C. Sarroca, J. Chem. Soc.
Dalton Trans. (1995) 3563.
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4. Supplementary material
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Complete crystallographic data (excluding structure
factors) have been deposited with the Cambridge Crys-
tallographic Data Centre under the numbers CCDC-
133385–133388. Copies can be obtained free of charge
from CCDC, 12 Union Road, Cambridge CB2 1EZ,
UK (Fax: +44-1223-336033; e-mail: deposit@
ccdc.cam.ac.uk).
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Acknowledgements
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We thank the Direccio´n General de Investigacio´n
Cient´ıfica y Te´cnica (No. PB97-1010-C02-01) and the
Fonds der Chemischen Industrie for financial support.
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