Synthesis of gold-(I) and -(III) complexes with diferrocenylphenylphosphine (PFc2Ph). Crystal structure of [Au(PFc2Ph)2]ClO4

Article abstract of DOI:10.1016/S0022-328X(98)01224-8

Diferrocenylphenylphosphine (PFc₂Ph) reacts with gold(I) derivatives to afford neutral, [AuR(PFc₂Ph)] (R = Cl, C₆F₅) or cationic complexes, [Au(PFc₂Ph)(PR₃)]ClO₄ (PR₃

Full text of DOI:10.1016/S0022-328X(98)01224-8

Journal of Organometallic Chemistry 579 (1999) 206–210
Synthesis of gold-(I) and -(III) complexes with
diferrocenylphenylphosphine (PFc2Ph). Crystal structure of
[Au(PFc2Ph)2]ClO4
M. Concepcio´n Gimeno a, Peter G. Jones b, Antonio Laguna a,*, Cristina Sarroca a
a Departamento de Qu´ımica Inorga´nica, ICMA, 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 21 September 1998; received in revised form 5 December 1998
Abstract
Diferrocenylphenylphosphine (PFc2Ph) reacts with gold(I) derivatives to afford neutral, [AuR(PFc2Ph)] (R=Cl, C6F5) or
cationic complexes, [Au(PFc2Ph)(PR3)]ClO4 (PR3=PFc2Ph, PPh3). Reaction with [Au(C6F5)3(OEt2)] or [Au(C6F5)2Cl]2 gives the
gold(III) complexes [Au(C6F5)3(PFc2Ph)] or [Au(C6F5)2Cl(PFc2Ph)], respectively. © 1999 Elsevier Science S.A. All rights reserved.
Keywords: Gold; Ferrocene; Diferrocenylphenylphosphine
1. Introduction
Here we report on the synthesis of mononuclear
gold(I) or gold(III) complexes with diferrocenylphenyl-
phosphine as ligand.
The chemistry of ferrocene and the design of new
ligands containing the ferrocene unit, such as the diphos-
phine 1,1%-bis(diphenylphosphino)ferrocene, have been
widely studied because of the potential applications of
such products in fields such as organic synthesis, homo-
geneous catalysis, material chemistry and the production
of fine chemicals [1,2]. However, the monophosphine
diferrocenylphenylphosphine (PFc2Ph) [3] has scarcely
been studied. Only a few complexes, such as [M-
(CO)5(PFc2Ph)] (M=Mo or W), [CoMe-(DH)2(PFc2-
Ph)] (DH=dimethylglioximate), [Ni(acac)2(PFc2Ph)]
[4], [Ag(TfO)(PFc2Ph)(PR3)] (TfO=trifluoromethane-
2. Results and discussion
Treatment of equimolecular amounts of [AuR(tht)]
(R=Cl or C6F5, tht=tetrahydrothiophene) with difer-
rocenylphenylphosphine (PFc2Ph) in dichloromethane
affords the neutral complexes [AuR(PFc2Ph)] [R=Cl
(1), C6F5 (2)] (Scheme 1). Compounds 1 and 2 are
moisture- and air-stable yellow solids. They behave as
non-conductors in acetone solution. In the IR spectrum,
the C6F5 group (2) gives rise to strong absorptions at
1505, 955 and 790 cm−1; w(AuꢀCl) (1) appears at 336
cm−1. In the positive ion liquid secondary ion mass
spectra (LSIMS) of both complexes, the most intense
peak corresponds to the molecular fragment
[AuR(PFc2Ph)]+ [m/z=710 (1) and 842 (2)]. For com-
plex 1 the peak assigned to [Au(PFc2Ph)]+ [m/z=675
(17%)] is also present.
sulfonate;
PR3=PFc2Ph,
PPh2Me,
PPh3),
[Ag(PFc2Ph)2(dptpm)]TfO (dptpm=bis(diph-enylthio-
phosphoryl)methane), [Ag(S2CNEt2) (PFc2-Ph)2] [5], or
the gold derivatives [AuCl(PFc2Ph)] [6], or more re-
cently, [Au(PFc2Ph)2]PF6 [7], have been reported.
* Corresponding author. Tel.: +34-976-761-185; fax: +34-976-
761-187.
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(98)01224-8

M.C. Gimeno et al. / Journal of Organometallic Chemistry 579 (1999) 206–210
207
Scheme 1. (i) [AuR(tht)], (ii) 1/2[Au(tht)2]ClO4, (iii) [Au(OClO3)(PPh3)], (iv) [Au(C6F5)3(OEt2)], (v) 1/2 [Au(C6F5)2Cl]2.
1
The H-NMR spectra show the expected four reso-
The geometry around the gold atom is distorted from
linearity with an angle PꢀAuꢀP of 169.41(6)°. The
nances for the four diastereotopic P(C5H4) protons
[4.50, 4.48, 4.46 and 4.22 (1) and 4.46, 4.43, 4.42 and
4.18 ppm (2)] and a singlet for the C5H5 rings [4.18 (1)
and 4.22 ppm (2)]. The 31P{1H}-NMR spectra show a
singlet (23.8 ppm) and a multiplet (32.7 ppm), arising
from the coupling with the fluorine atoms, for com-
plexes 1 and 2, respectively. The 19F-NMR spectrum of
2 presents two multiplets at −116.5 and −162.6 ppm
and a triplet at −158.9 ppm [J(FꢀF)=19.3 Hz], corre-
sponding to the ortho-, meta- and para-F, respectively.
The reaction of [Au(tht)2]ClO4 with the phosphine in
˚
AuꢀP distances are 2.293(2) and 2.301(2) A, which are
significantly longer than the corresponding values of
˚
2.234(2) A in [AuCl(PFc2Ph)] [6] but are similar to
those found in other bis(phosphine) gold compounds
such as [Au(PR3)2]+ [PR3=PPh2Me, 2.316(4) A; PCy3,
˚
˚
2.321(2) A] [8,9]. This is consistent with the strong
mutual trans influence of phosphine ligands. There are
two shorter intramolecular gold–iron distances of
˚
4.055(1) and 4.073(1) A associated with the narrower
PꢀAuꢀP angle.
a
1:2 molar ratio gives the cationic complex
[Au(PFc2Ph)2]ClO4 (3). Acetone solutions of complex 3
behave as 1:1 electrolytes. The solid IR spectrum pre-
sents bands at 1093 (vs, br) and 623 cm−1 (s), arising
from ionic ClO4−. In the LSIMS+ spectrum, the most
intense
peak
corresponds
to
the
fragment
1
[Au(PFc2Ph)2]+ [m/z=1153]. The H-NMR spectrum
shows the resonances of the P(C5H4) protons at 4.72,
4.68, 4.62 and 4.43 ppm and a singlet for the C5H5 rings
at 4.23 ppm. The 31P{1H}-NMR spectrum presents a
singlet at 37.2 ppm.
The structure of complex 3 was confirmed by an
X-ray diffraction analysis. It crystallises in the space
group P1 as a CHCl3 solvate. The molecule is shown in
Fig. 1, with selected bond lengths and angles in Table 1.
The bond lengths and angles are very similar to those
found for the complex [Au(PFc2Ph)2]PF6 · CHCl3 [7],
which appears to be isostructural, although the triclinic
cell was presented differently.
Fig. 1. The cation of complex 3 in the crystal showing the atom
numbering scheme. Radii are arbitrary. H atoms are omitted for
clarity.

208
M.C. Gimeno et al. / Journal of Organometallic Chemistry 579 (1999) 206–210
Table 1
respectively, to give the gold(III) complexes
[Au(C6F5)3(PFc2Ph)] (5) or [Au(C6F5)2Cl(PFc2Ph)] (6).
Complexes 5 and 6 are white solids, moisture- and
air-stable. They are non-conductors in acetone solu-
tions. Their IR spectra show bands at 1507(s), 969(s),
820(m) and 792(m) (5) and 1513(s), 1506(s), 969(s),
807(m) and 788(m) cm−1, corresponding to the C6F5
groups; w(AuꢀCl) appears at 337(m) cm−1 (complex 6).
In the LSIMS+ mass spectra of both complexes, the
molecular peak [M]+ [m/z=1176 (42) (1) and 1044
(42%) (2)] is present. The peak assigned to
[Au(C6F5)(PFc2Ph)]+ [m/z=842 (7, 5) (11%, 6)] is also
present.
The complexes 5 and 6 were readily characterised by
1H-, 19F- and 31P{1H}-NMR. Their 31P{1H}-NMR
spectra show a singlet at 12.2 (5) and 23.2 ppm (6). The
19F-NMR spectra show the presence of two different
types of pentafluorophenyl groups (with a 2:1 intensity
ratio for complex 5), which confirms the mutually cis
position in complex 6 (see Section 3).
˚
Selected bond lengths (A) and angles (°) for complex 3
Bond lengths
AuꢀP(1)
P(1)ꢀC(11)
P(1)ꢀC(51)
P(2)ꢀC(41)
2.2929(18) AuꢀP(2)
2.3005(17)
1.775(7)
1.801(7)
1.807(7)
1.765(8)
1.813(8)
1.805(7)
P(1)ꢀC(21)
P(2)ꢀC(31)
P(2)ꢀC(61)
Bond angles
P(1)ꢀAuꢀP(2)
C(11)ꢀP(1)ꢀC(51) 105.3(3)
C(11)ꢀP(1)ꢀAu
C(51)ꢀP(1)ꢀAu
C(31)ꢀP(2)ꢀC(61) 106.5(3)
C(31)ꢀP(2)ꢀAu
C(61)ꢀP(2)ꢀAu
C(12)ꢀC(11)ꢀP(1) 125.6(6)
P(1)ꢀC(21)ꢀFe(2) 124.8(4)
C(35)ꢀC(31)ꢀP(2) 124.0(5)
C(45)ꢀC(41)ꢀP(2) 125.1(6)
P(2)ꢀC(41)ꢀFe(4) 124.1(3)
C(52)ꢀC(51)ꢀP(1) 121.5(6)
C(66)ꢀC(61)ꢀP(2) 119.7(5)
169.41(6)
C(11)ꢀP(1)ꢀC(21) 103.2(3)
C(21)ꢀP(1)ꢀC(51) 107.3(3)
119.6(2)
111.4(2)
C(21)ꢀP(1)ꢀAu
109.1(2)
C(31)ꢀP(2)ꢀC(41) 106.9(3)
C(41)ꢀP(2)ꢀC(61) 104.1(3)
107.7(2)
111.6(2)
C(41)ꢀP(2)ꢀAu
119.4(2)
C(15)ꢀC(11)ꢀP(1) 126.9(6)
P(1)ꢀC(11)ꢀFe(1) 134.1(4)
C(32)ꢀC(31)ꢀP(2) 126.6(5)
P(2)ꢀC(31)ꢀFe(3) 123.1(4)
C(42)ꢀC(41)ꢀP(2) 127.3(5)
C(56)ꢀC(51)ꢀP(1) 119.4(6)
C(62)ꢀC(61)ꢀP(2) 121.4(5)
3. Experimental
The cyclopentadienyl rings within each ferrocenyl
unit are almost eclipsed, as expressed by the torsion
angles C–center–center–C of 13, 10, 5 and 5° for Fe1,
Fe2, Fe3 and Fe4, respectively, around the Cp···Cp
axis. The CꢀPꢀAu angles for the ferrocenyl-C atoms are
significantly different from each other, as has been
previously observed in the two diferrocenylphenylphos-
phino-gold complexes reported [6,7]. These angles vary
from 109.1(2)° for C(21)ꢀP(1)ꢀAu to 119.6(2)° for
C(21)ꢀP(1)ꢀAu and from 107.7(2)° for C(31)ꢀP(2)ꢀAu
to 119.4(2)° for C(41)ꢀP(2)ꢀAu. This large angular dif-
ference has been associated [7] with the short in-
tramolecular interactions between the ferrocenyl ring
carbon atoms and the phenyl ring hydrogen atoms, e.g.
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 and H analyses
were carried out with a Perkin–Elmer 2400 microana-
lyzer. 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 relative to SiMe4
(1H, external), CFCl3 (19F, external) and 85% H3PO4
(31P, external). The starting materials PFc2Ph [3], [Au-
Cl(tht)] [10], [Au(C6F5)(tht)] [10], [Au(tht)2]ClO4 [11]
[Au(C6F5)3(OEt2)] [12] and [Au(C6F5)2Cl]2 [13], were
prepared by published procedures. [Au(OClO3)(PPh3)]
was prepared from [AuCl(PPh3)] [14] and AgClO4.
˚
˚
C(21)···H(52) 2.69 A, C(31)···H(62) 2.77 A.
The reaction of equimolar amounts
of
[Au(OClO3)(PPh3)] and the phosphine leads to the com-
plex [Au(PFc2Ph)(PPh3)]ClO4 (4). However, in solution,
complex 4 is in equilibrium with the homoleptic species
[Au(PFc2Ph)2]+ (3) and [Au(PPh3)2]+. Thus, the
31P{1H}-NMR spectrum presents resonances from the
three complexes: a singlet at 37.2 ppm, from complex 3;
a singlet at 45.4 ppm, from [Au(PPh3)2]+; and four
resonances, corresponding to an AB system
[l(PFc2Ph)=38.1, l(PPh3)=45.1 ppm, J(AB)=342.3
Hz] assigned to complex 4. In the LSIMS+ mass
spectrum, the most intense peak corresponds to the
cation molecular peak [Au(PFc2Ph)(PPh3)]+ [m/z=
937]. Additionally, other fragments correspond to
[Au(PFc2Ph)2]+ (1153, 10%) and [Au(PPh3)2]+ (721,
60%).
3.1. Syntheses
3.1.1. [AuR(PFc2Ph)] [R=Cl (1), C6F5 (2)]
To a solution of PFc2Ph (0.048 g, 0.1 mmol) in
dichloromethane (20 cm3), [AuCl(tht)] (0.032 g, 0.1
mmol) or [Au(C6F5)(tht)] (0.045 g, 0.1 mmol) were
added and the mixture was stirred for 2 h. The solution
was concentrated to ca. 5 cm3 and addition of diethyl
ether (15 cm3) gave complexes 1 or 2 as yellow solids.
Complex
1:
Yield
56%,
Anal.
Calc.
for
C26H23AuClFe2P: C, 43.95; H, 3.25. Found: C, 43.65,
H, 3.2; \M 12 V−1 cm2 mol−1. Complex 2: Yield 66%,
Anal. Calc. for C32H23AuF5Fe2P: C, 45.65; H, 2.75.
Diferrocenylphenylphosphine reacts with [Au(C6F5)3-
(OEt2)] or [Au(C6F5)2Cl]2, in molar ratio 1:1 or 2:1,
Found: C, 45.35, H, 2.8; \M 9 V−1 cm2 mol−1
.

M.C. Gimeno et al. / Journal of Organometallic Chemistry 579 (1999) 206–210
209
3
˚
3.1.2. [Au(PFc2Ph)2]ClO4 (3)
111.475(10)°, V=2454.9(6) A , Z=4, Dcalc. =1.810
−1
Mg m−3, u(Mo–Ka)=0.71073 A, v=4.41 mm
,
˚
To a solution of PFc2Ph (0.096 g, 0.2 mmol) in
dichloromethane (20 cm3), [Au(tht)2]ClO4 (0.047 g, 0.1
mmol) was added and the mixture was stirred for 2 h.
The solution was concentrated to ca. 5 cm3 and addi-
tion of diethyl ether (15 cm3) gave complex 3 as a
yellow solid. Yield 92%, Anal. Calc. for
C52H46AuClFe4O4P2: C, 49.95; H, 3.7. Found: C, 50.35,
F(000)=1324, T= −100°C.
3.2.2. Data collection and reduction
Single crystals were obtained by slow diffusion of
hexane into a chloroform solution of complex 3. A
yellow plate 0.80×0.20×0.15 mm3 was used to collect
14 113 intensities to 2qmax 50° (Siemens P4 diffractome-
ter, monochromated Mo–Ka radiation) of which 8545
were independent (Rint=0.049). Cell constants were
refined from 2q values of 65 reflections in the range
10.6–25°. An absorption correction was applied on the
basis of „-scans (transmission factors 0.90–0.98).
H, 3.7; \M 115 V−1 cm2 mol−1
.
3.1.3. [Au(PFc2Ph)(PPh3)]ClO4 (4)
To a solution of [Au(OClO3)(PPh3)] (0.104 g, 0.1
mmol) in dichloromethane (20 cm3), PFc2Ph (0.048 g,
0.1 mmol) was added and the mixture was stirred for 15
min. The solution was concentrated to ca. 5 cm3 and
addition of diethyl ether (15 cm3) gave complex 4 as a
yellow solid. Yield 72%, Anal. Calc. for
C44H38AuClFe2O4P2: C, 50.95; H, 3.7. Found: C, 50.65,
H, 3.75; \M 115 V−1 cm2 mol−1, 1H-NMR, l ppm: 7.6
(m, 20H, Ph), 4.57, 4.21 and 4.00 [m, 6H, P(C5H4)] and
4.08 [m, 12H, 2H of P(C5H4) and 10H of C5H5]. There
are also present the resonances due to complex 3 and
[Au(PPh3)2]ClO4.
3.2.3. Structure solution and refinement
The structure was solved by the heavy atom method
and refined on F2 using the program SHELXL-93 [15].
All non-hydrogen atoms were refined anisotropically.
Refinement proceeded to wR (F2) 0.102 for 8542 reflec-
tions, 599 parameters and 534 restraints (to local ring
symmetry and light atom displacement factors), with
conventional R(F) 0.0429, S(F2) 1.03, max. Dz=1.57 e
−3
˚
A
.
3.1.4. [Au(C6F5)3(PFc2Ph)] (5) and
[Au(C6F5)2Cl(PFc2Ph)] (6)
To a dichloromethane solution (20 cm3) of PFc2Ph
(0.048 g, 0.1 mmol), [Au(C6F5)3(OEt2)] (0.077 g, 0.1
mmol) or [Au(C6F5)2Cl]2 (0.042 g, 0.05 mmol) were
added. The mixture was stirred for 1 h and then the
solution was concentrated under vacuum to ca. 5 cm3;
addition of hexane (15 cm3) afforded complexes 5 or 6
as a pale orange or orange solid, respectively. Complex
5: Yield 55%, Anal. Calc. for C44H23AuF15Fe2P: C,
44.95; H, 1.95. Found: C, 44.95, H, 2.0; \M 9 V−1 cm2
4. Supplementary material
Complete crystallographic data (excluding structure
factors) have been deposited at the Cambridge Crystal-
lographic Data Centre under the number CCDC-
103032. Copies can be obtained free of charge from
CCDC, 12 Union Road, Cambridge CB2 1EZ, UK
(Fax: +44-1223-336-033; e-mail: deposit@ccdc.cam.
ac.uk).
1
mol−1. H-NMR, l ppm: 7.5 (m, 5H, Ph), 4.50, 4.52
and 4.05 [m, 8H, P(C6H4)] and 4.09 (s, 10 H, C5H5).
19F-NMR, l ppm: −119.3 (m, 4F, Fo), −121.6 (m,
2F, Fo), −157.8 [t, 1F, Fp, J(FꢀF) 19.3 Hz], −157.9 [t,
2F, Fp, J(FꢀF) 20.67 Hz], −161.3 (m, 4F, Fm) and
−161.62 (m, 2F, Fm). Complex 6: Yield 60%, Anal.
Calc. for C38H23AuClF10Fe2P: C, 43.7; H, 2.2. Found:
Acknowledgements
The authors thank the Direccio´n General de Inves-
tigacio´n Cient´ıfica y Te´cnica (No. PB97-1010-C02-01)
and the Fonds der Chemischen Industrie for financial
support.
1
C, 43.35, H, 2.1; \M 12 V−1 cm2 mol−1. H-NMR, l
ppm: 7.5 (m, 5H, Ph), 4.67, 4.62, 4.55 and 4.53 [m, 8H,
P(C6H4)] and 4.32 (s, 10 H, C5H5). 19F-NMR, l ppm:
−120.3 (m, 2F, Fo), −123.1 (m, 2F, Fo), −157.4 [t,
1F, Fp, J(FꢀF) 19.97 Hz], −158.0 [t, 1F, Fp, J(FꢀF)
19.97 Hz], −160.8 (m, 2F, Fm) and −161.5 (m, 2F,
Fm).
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˚
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