Selenolate gold complexes with aurophilic Au(I)-Au(I) and Au(I)-Au(III) interactions

Article abstract of DOI:10.1021/ic0493806

The gold(I) selenolate compound [Au₂(SePh)₂(μ- dppf)] (dppf = 1,1‰-bis(diphenylphosphino)ferrocene) has been prepared by reaction of [Au₂Cl₂(μ-dppf)] with PhSeSiMe₃ in a molar ratio 1:2. This complex reacts with gold(I) or gold(III) derivatives to give polynuclear gold(I)-gold(I) or gold(I)-gold(III) complexes of the type [Au₄(μ-SePh)₂-(PPh₃)₂(μ-dppf)] (OTf)₂, [Au₃(C₆F₅) ₃(μ-SePh)₂(μ-dppf)], or [Au₄(C ₆F₅)₆(μ-SePh)₂(μ-dppf)], with bridging selenolate ligands. The reaction of [Au₂(SePh) ₂(μ-dppf)] with 1 equiv of AgOTf leads to the formation of the insoluble Ag(SePh) and the compound [Au₂(μ-SePh)(μ-dppf)]OTf. The complexes [Au₄(C₆F₅)₆(μ-SePh) ₂(μ-dppf)] and [Au₂(μ-SePh)(μ-dppf)]OTf (two different solvates) have been characterized by X-ray diffraction studies and show the presence of weak gold(I)-gold(III) interactions in the former and intra- and intermolecular gold(I)-gold(I) interactions in the later.

Full text of DOI:10.1021/ic0493806

Inorg. Chem. 2004, 43, 7234−7238
Selenolate Gold Complexes with Aurophilic Au(I)
Interactions
−Au(I) and Au(I)−Au(III)
Silvia Canales,† Olga Crespo,† M. Concepcio´n Gimeno,*,† Peter G. Jones,‡ and Antonio Laguna†
Departamento de Qu´ımica Inorga´nica, Instituto de Ciencia de Materiales de Arago´n, UniVersidad
de Zaragoza-CSIC, E-50009 Zaragoza, Spain, and Institut fu¨r Anorganische und Analytische
Chemie der Technischen UniVersita¨t, Postfach 3329, D-38023 Braunschweig, Germany
Received May 12, 2004
The gold(I) selenolate compound [Au2(SePh)2(
prepared by reaction of [Au2Cl2( -dppf)] with PhSeSiMe3 in a molar ratio 1:2. This complex reacts with gold(I) or
gold(III) derivatives to give polynuclear gold(I) gold(I) or gold(I) gold(III) complexes of the type [Au4( -SePh)2-
(PPh3)2( -dppf)](OTf)2, [Au3(C6F5)3( -SePh)2( -dppf)], or [Au4(C6F5)6( -SePh)2( -dppf)], with bridging selenolate
ligands. The reaction of [Au2(SePh)2( -dppf)] with 1 equiv of AgOTf leads to the formation of the insoluble
Ag(SePh) and the compound [Au2( -SePh)( -dppf)]OTf. The complexes [Au4(C6F5)6( -SePh)2( -dppf)] and
[Au2( -SePh)( -dppf)]OTf (two different solvates) have been characterized by X-ray diffraction studies and show
µ-dppf)] (dppf ) 1,1′-bis(diphenylphosphino)ferrocene) has been
µ
−
−
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
the presence of weak gold(I)
actions in the later.
−gold(III) interactions in the former and intra- and intermolecular gold(I)−gold(I) inter-
Introduction
dation states are even more poorly represented, with only
one gold(II) [Au2Cl(SePh){µ-(CH2)2PPh2}2]8 and no
gold(III) derivatives having been described.
Gold complexes with thiolate ligands have been thoroughly
studied because of their importance in several applications
such as in medicine, in the glass and ceramics industry, and
in the field of nanoparticles.1,2 However, it is surprising that
the analogous gold selenolate chemistry has scarcely been
studied until now, despite the great possibilities that the
compounds can offer, and only a few complexes have been
reported. These include mononuclear gold(I) complexes of
the type [Au(SeR)(PR3)] (R ) Ph, naphthyl),3,4 dinuclear
gold(I) derivatives such as [Au2(µ-SeR)2L2] (R ) Ph,
4-ClC6F4, CH2Ph, naphthyl, 4-NH2C6H4, 4-ClC6H4; L )
PPh3, PPh2Me, PPhMe2; L2 ) dppm, dppe),3-6 or heterodi-
nuclear [WCo(CO)3Se(CH2SiMe3)AuPPh3]SbF6.7 Other oxi-
We are currently working on the chemistry of gold with
selenium ligands, and thus, we have reported on gold com-
plexes with a central selenido ligand,9-11 phosphine se-
lenides,12,13 and selenoethers,14 and recently on gold com-
plexes with the o-carboranyl selenolate ligand.15 Here we
report on the synthesis of the dinuclear selenolate compound
[Au2(SePh)2(µ-dppf)] and its reactivity with various metal
fragments such as gold(I), gold(III), or silver salts, leading,
as one example, to the synthesis of the first mixed gold(I)-
gold(III) derivatives with selenolate ligands. The crystal
(7) Eikens, W.; Jones, P. G.; Tho¨ne, C. Z. Anorg. Allg. Chem. 1997, 623,
735.
(8) Porter, L. C.; Fackler, J. P., Jr. Acta Crystallogr., Sect. C 1987, 43,
29.
(9) Canales, S.; Crespo, O.; Gimeno, M. C.; Jones, P. G.; Laguna, A.
Chem. Commun. 1999, 679.
(10) Canales, S.; Crespo, O.; Gimeno, M. C.; Jones, P. G.; Laguna, A.;
Mendizabal, F. Organometallics 2000, 19, 4985.
* To whom correspondence should be addressed. E-mail: gimeno@
unizar.es.
† Universidad de Zaragoza-CSIC.
‡ Institut fu¨r Anorganische und Analytische Chemie der Technischen
Universita¨t.
(1) Gimeno, M. C.; Laguna, A. ComprehensiVe Coordination Chemistry
II; McCleverty, J. A., Meyer, T. J., Eds.; Elsevier: New York, 2003;
Vol. 5, p 911.
(2) Gold, Progress in Chemistry, Biochemistry and Technology; Schmid-
baur, H., Ed.; Wiley: Chichester, U.K., 1999.
(3) Jones, P. G.; Tho¨ne, C. Chem. Ber. 1990, 123, 1975.
(4) Eikens, W.; Kienitz, C.; Jones, P. G.; Tho¨ne, C. J. Chem. Soc., Dalton
Trans. 1994, 83.
(5) Jones, P. G.; Tho¨ne, C. Z. Naturforsch., B: Chem. Sci. 1992, 47, 600.
(6) Jones, P. G.; Lautner, J.; Tho¨ne, C. Z. Kristallogr. 1993, 208, 354.
(11) Canales, S.; Crespo, O.; Gimeno, M. C.; Jones, P. G.; Laguna, A.;
Mendizabal, F. Organometallics 2001, 20, 4812.
(12) Canales, S.; Crespo, O.; Gimeno, M. C.; Jones, P. G.; Laguna, A. J.
Organomet. Chem. 2000, 613, 50.
(13) Canales, S.; Crespo, O.; Gimeno, M. C.; Jones, P. G.; Laguna, A.;
Silvestru, A.; Silvestru, C. Inorg. Chim. Acta 2003, 347, 16.
(14) Canales, S.; Crespo, O.; Fortea, A.; Gimeno, M. C.; Jones, P. G.;
Laguna, A. J. Chem. Soc., Dalton Trans. 2002, 2250.
(15) Canales, S.; Crespo, O.; Gimeno, M. C.; Jones, P. G.; Laguna, A.;
Romero, P. J. Chem. Soc., Dalton Trans. 2003, 4525.
7234 Inorganic Chemistry, Vol. 43, No. 22, 2004
10.1021/ic0493806 CCC: $27.50
© 2004 American Chemical Society
Published on Web 10/07/2004

Selenolate Gold Complexes
a
Scheme 1
a (i) 2PhSeSiMe3, (ii) 2[Au(OTf)(PPh3)], (iii) [Au(C6F5)3(OEt2)], (iv) 2[Au(C6F5)3(OEt2)], (v) Ag(OTf).
1
structures of two of these complexes reveal the presence of
anion. The H NMR spectrum presents the two multiplets
gold(I)-gold(I) and weak gold(I)-gold(III) interactions.
for the R and â protons of the substituted cyclopentadienyl
rings at 4.21 and 4.56 ppm and also a multiplet around 7.4
ppm for the phenyl protons. The 31P(1H) NMR spectrum
shows two singlets corresponding to the two different
phosphorus environments; the phosphorus of the dppf ligand
appears at 31.0 and the phosphorus of the PPh3 at 36.2 ppm.
The assignment has been made by comparison with other
“Se-Au-PPh3” or “Au-dppf” complexes.10
Results and Discussion
Synthesis of the Complexes. The reaction of [Au2Cl2-
(µ-dppf)] with 2 equiv of PhSeSiMe3 in tetrahydrofuran gives
the dinuclear selenolate compound [Au2(SePh)2(µ-dppf)] (1)
(see Scheme 1). Complex 1 is an air- and moisture-stable
solid that behaves as a nonconductor in acetone solution.
1
The reaction of complex 1 with 1 equiv of [Au(C6F5)3-
(OEt2)] leads to the complex [Au3(C6F5)3(µ-SePh)2(µ-dppf)]
(3). Complex 3 is an air- and moisture-stable orange solid
that behaves as a nonconductor in acetone solution. The IR
spectrum shows the typical absorptions for pentafluorophenyl
The H NMR spectrum displays two multiplets at 4.14 and
4.45 ppm for the R and â protons of the cyclopentadienyl
rings, respectively, and a broad multiplet for the phenyl
protons around 7.5 ppm. The 31P(1H) NMR spectrum shows
one singlet for the two equivalent phosphorus atoms at 33.0
ppm. The liquid secondary-ion positive mass spectrum
(LSIMS+) does not show the presence of the molecular peak,
but the fragment arising from the loss of one selenolate ligand
appears at m/z ) 1105 (60%). The loss of one anionic ligand
such as a halogen or pseudo-halogen in the LSIMS+ spectra
is a relatively common feature in neutral complexes.15-17
Complex 1 can react with gold(I) or gold(III) derivatives
leading to gold(I)-gold(I) or mixed gold(I)-gold(III) com-
plexes with a bridging selenolate ligand. Thus, the reac-
tion of 1 with 2 equiv of [Au(OTf)(PPh3)] affords the
tetranuclear derivative [Au4(µ-SePh)2(PPh3)2(µ-dppf)](OTf)2
(2). Compound 2 is an air- and moisture-stable orange
solid that behaves as a 1:2 electrolyte in acetone solution.
The IR spectrum shows the typical absorptions for the triflate
1
units bonded to gold(III). The H NMR spectrum shows
broad signals at 4.17 and 4.42 ppm for the R and the â
protons of the cyclopentadienyl rings, respectively, and also
for the phenyl protons. In the 31P(1H) spectrum, only one
resonance for the two phosphorus atoms is present. The 19
F
NMR spectrum shows the presence of two different types
of pentafluorophenyl groups, and five signals appear, which
are overlapped; two for the ortho, two for the para, in a
ratio 1:2, and only one signal for the meta fluorine. The NMR
spectra were also recorded at -85 °C but showed no differ-
ence from those at room temperature. With respect to the
coordination of the gold(III) center to the selenolate ligands,
we can thus propose either a rare pentacoordination of the
gold atom bonded to both selenium atoms, or, more probably,
(16) Crespo, O.; Canales, F.; Gimeno, M. C.; Jones, P. G.; Laguna, A.
(17) Canales, F.; Gimeno, M. C.; Jones, P. G.; Laguna, A.; Sarroca, C.
Organometallics 1999, 18, 3142.
Inorg. Chem. 1997, 36, 5206.
Inorganic Chemistry, Vol. 43, No. 22, 2004 7235

Canales et al.
Table 1. Bond Distances (Å) and Lengths (deg) for Compound 4
Au(1)-C(31)
Au(1)-C(51)
Au(1)-C(41)
Au(1)-Se(1)
Au(2)-P(1)
Au(2)-Se(1)
Se(1)-C(61)
Au(3)-C(91)
Au(3)-C(101)
Au(3)-C(111)
Au(3)-Se(2)
2.036(3)
2.066(3)
2.076(3)
2.4878(4)
2.2647(11)
2.4408(5)
1.933(4)
2.051(4)
2.054(3)
2.061(3)
2.4896(4)
Au(4)-P(2)
Au(4)-Se(2)
Se(2)-C(121)
P(1)-C(1)
P(1)-C(21)
P(1)-C(11)
P(2)-C(6)
P(2)-C(71)
P(2)-C(81)
2.2722(11)
2.4392(5)
1.941(4)
1.794(4)
1.812(4)
1.816(4)
1.792(4)
1.816(4)
1.820(4)
P(1)-Au(1)-Se(1)
P(1)-Au(1)-Au(2)
Se(1)-Au(1)-Au(2)
P(2)-Au(2)-Se(1)
P(2)-Au(2)-Au(3)
Se(1)-Au(2)-Au(3)
P(2)-Au(2)-Au(1)
Se(1)-Au(2)-Au(1)
175.36(8) Au(2)-Au(3)-Au(4)
123.88(7) P(4)-Au(4)-Se(2)
52.28(3) P(4)-Au(4)-Au(3)
170.03(7) Se(2)-Au(4)-Au(3)
101.38(7) C(51)-Se(1)-Au(1)
87.44(3) C(51′)-Se(1)-Au(1)
119.13(7) C(51)-Se(1)-Au(2)
51.78(3) C(51′)-Se(1)-Au(2)
137.01(2)
177.54(8)
125.25(7)
52.97(3)
108.3(6)
101.2(6)
94.9(6)
Figure 1. Molecular structure of compound 4 showing the atom numbering
scheme. Displacement parameter ellipsoids represent 50% probability
surfaces. Phenyl carbon atoms with the exception of the ipso carbon and
hydrogen atoms omitted for clarity.
109.9(8)
75.94(3)
Au(3)-Au(2)-Au(1) 139.18(2) Au(1)-Se(1)-Au(2)
a rapid exchange of the Au(C6F5)3 fragment between both
coordination sites. The presence of a four-coordinate fast
exchange derivative is also supported for the small differ-
ences in the 19F NMR chemical shifts of 3 compare with
those of the complex with two Au(C6F5)3 groups (4, see
below).
P(3)-Au(3)-Se(2)
P(3)-Au(3)-Au(2)
Se(2)-Au(3)-Au(2)
P(3)-Au(3)-Au(4)
Se(2)-Au(3)-Au(4)
170.32(7) C(111)-Se(2)-Au(4) 103.2(3)
96.54(7) C(111)-Se(2)-Au(3) 101.7(3)
91.59(3) Au(4)-Se(2)-Au(3)
74.62(3)
117.98(7)
52.41(3)
distances between the gold(I) and the gold(III) centers, 3.693
Å for Au(1)-Au(2) and 3.578 Å for Au(3)-Au(4), to-
gether with very narrow Au-Se-Au angles, 74.62(3)° and
75.94(3)°, point out the presence of weak gold(I)-gold(III)
interactions. Although these distances are long compared with
those corresponding to Au(I)-Au(I) interactions, we have
described several mixed valence derivatives with a central
sulfur or selenium ligand in which we have postulated the
presence of weak Au(I)-Au(III) contacts with bond distances
ranging from 3.2 to 3.6 Å with corresponding interactions
energies in the range 21-25 kJ mol-1.11,18 Theoretical studies
at the HF and MP2 level have been carried out for these
complexes11,18 and others,19,20 supporting the existence of
Au(I)-Au(III) and even Au(III)-Au(III) interactions. These
studies support the idea that the aurophilic interaction can
exist for oxidation state Au(III), although it is much weaker
than in gold(I) centers.19 In the analogous pentafluorophe-
nylthiolate derivative [Au4(C6F5)6{µ-S(C6F5)}2(µ-dppf)], the
gold(I)-gold(III) distance is 3.608(2) Å (despite the close
similarity of cell constants, the two compounds are not
isostructural; this can be seen in the widely differing ligand
conformations, with a P-Cent-Cent-P torsion angle of
100.5° in the S(C6F5) derivative, and in the different space
groups).16 It is therefore reasonable to propose a weak
interaction between the gold atoms in the mixed valence
complex. The gold(III) centers display square-planar geom-
etries; both of them lie in the plane formed by three carbons
and a selenium donor atom. The Au-C distances range from
2.036(3) to 2.076(3) Å, the shorter values correspond to the
Au-C bond trans to the selenium atoms (Au(1)-C(31)
2.036(3) Å, Au(3)-C(91) 2.051(4) Å), but the difference
at Au(3) is scarcely significant. This fact may reflect the
If the same reaction is carried out in molar ratio 1:2, the
complex [Au4(C6F5)6(µ-SePh)2(µ-dppf)] (4) is isolated. Com-
pound 4 is an air- and moisture-stable orange solid that
behaves as a nonconductor in acetone solution. The 1H NMR
spectrum shows multiplets at 4.37 and 4.71 ppm, which are
assigned at the R and â protons of the cyclopentadienyl units,
and another multiplet ranging from 6.9 to 7.5 ppm for the
phenyl protons. The 31P(1H) NMR spectrum presents only
one signal at 32.6 ppm for the equivalent phosphorus atoms.
The 19F NMR spectrum shows the expected equivalence of
the Au(C6F5)3 groups. Consequently, six resonances appear,
two in the ortho, two in the meta, and two in the para region
with a ratio 1:2, which is a consequence of the equivalence
of the pentafluorophenyl groups in trans position in the
Au(C6F5)3 groups.
The treatment of 1 with the silver salt Ag(OTf) involves
the elimination of one selenolate group as [Ag(SePh)]n and
formation of a cyclic complex with a bridging selenolate
ligand, [Au2(µ-SePh)(µ-dppf)]OTf (5). Compound 5 is an
air- and moisture-stable orange solid that behaves as a 1:1
electrolyte in acetone solution. The 1H NMR spectrum shows
two multiplets at 4.18 and 4.55 ppm that are assigned to the
R and â protons of the substituted cyclopentadienyl rings.
In the 31P(1H) NMR spectrum, one resonance appears at 31.1
ppm for the two equivalent phosphorus atoms. The LSIMS+
shows the cationic molecular peak at m/z ) 1105 (75%).
Crystal Structures. The crystal structure of complex 4
has been established by X-ray diffraction; the molecule is
shown in Figure 1. Selected bond lengths and angles are
collected in Table 1. Compound 4 consists of a dppf ligand
bridging two “Au(µ-SePh)Au(C6F5)3” units, within each of
which the selenolato ligand bridges the gold(I) and the gold-
(III) fragments. The cyclopentadienyl rings are staggered with
a torsion angle C(1)-Cent-Cent-C(8) of 23.5° (Cent )
ring centroid); the phosphorus substituents subtend a torsion
angle of -167.5° across the centroids. The gold‚‚‚gold
(18) Calhorda, M. J.; Canales, F.; Gimeno, M. C.; Jime´nez, J.; Jones, P.
G.; Laguna, A.; Veiros, L. F. Organometallics 1997, 16, 3837.
(19) Mendizabal, F.; Pyykko¨, P. Phys. Chem. Chem. Phys. 2004, 6, 900.
(20) Mendizabal, F.; Zapata-Torres, G.; Olea-Azar, C. Chem. Phys. Lett.
2003, 382, 92.
7236 Inorganic Chemistry, Vol. 43, No. 22, 2004

Selenolate Gold Complexes
and 2.9788(14) Å) and intramolecular (2.9666(14) Å)
distances are very similar, and the Au-S-Au angles are
slightly wider, 77.59(17)° and 78.75(16)°. This is consistent
with that observed in isostructural [E(AuPPh3)4](OTf)2 (E
) S, Se) where narrow Au-E-Au angles and longer
Au-Au distances are observed for the selenium derivative.9,21
The four gold centers in the resulting tetranuclear array
show distorted linear geometries. The major distortion
corresponds to the connected gold centers of different
units [P(2)-Au(2)-Se(1), 170.03(7)°; P(3)-Au(3)-Se(2),
170.32(7)°].
The Au-Se bond distances (2.4454(12)-2.4706(11) Å)
are in the range of those found in other complexes in
which the selenium atom acts as a triply bridging ligand,
as in [Au2(µ-dppf){Se{Au2(µ-dppf)}2](OTf)2 (2.4240(10)-
2.704(10) Å).10 The Au(I)-P bond lengths, 2.273(3)-
2.288(3) Å, are shorter than in [Au2(µ-dppf){Se{Au2-
(µ-dppf)}2](OTf)2 (2.259(3)-2.280(3) Å).10 A second solvate
of complex 5, 5′, with two independent formula units plus
three dichloromethane molecules in the asymmetric unit, was
also analyzed and displays a closely similar structure with
analogous Au‚‚‚Au contacts (however, despite similar cells,
the two forms are not isostructural because the motif of
chains of cations in the regions x ≈ 0.25 is mutually shifted
parallel to the z axis). Data for 5′ are summarized in Table
4 and may be found in full in the Supporting Information.
Figure 2. Structure of the two cations in 5 showing the atom numbering
scheme. Displacement parameter ellipsoids represent 50% probability
surfaces. Phenyl carbon atoms with the exception of the ipso carbon and
hydrogen atoms omitted for clarity.
Table 2. Bond Distances (Å) and Lengths (deg) for Compound 5
Au(1)-P(1)
Au(1)-Se(1)
Au(1)-Au(2)
Au(2)-P(2)
Au(2)-Se(1)
Au(2)-Au(3)
2.273(3)
Au(3)-P(3)
Au(3)-Se(2)
Au(3)-Au(4)
Au(4)-P(4)
Au(4)-Se(2)
2.288(3)
2.4454(12)
3.0193(7)
2.275(3)
2.4621(13)
2.9238(7)
2.4706(11)
2.9839(7)
2.274(3)
2.4523(12)
P(1)-Au(1)-Se(1)
P(1)-Au(1)-Au(2)
Se(1)-Au(1)-Au(2)
P(2)-Au(2)-Se(1)
P(2)-Au(2)-Au(3)
Se(1)-Au(2)-Au(3)
P(2)-Au(2)-Au(1)
Se(1)-Au(2)-Au(1)
175.35(8) Se(2)-Au(3)-Au(4)
123.88(7) Au(2)-Au(3)-Au(4)
52.28(3) P(4)-Au(4)-Se(2)
170.03(7) P(4)-Au(4)-Au(3)
101.38(7) Se(2)-Au(4)-Au(3)
87.44(3) C(51)-Se(1)-Au(1)
119.13(7) C(51′)-Se(1)-Au(1)
51.78(3) C(51)-Se(1)-Au(2)
52.41(3)
137.01(2)
177.54(8)
125.25(7)
52.97(3)
108.3(6)
101.2(6)
94.8(6)
Au(3)-Au(2)-Au(1) 139.18(2) C(51′)-Se(1)-Au(2)
109.8(8)
75.94(3)
Experimental Section
P(3)-Au(3)-Se(2)
P(3)-Au(3)-Au(2)
Se(2)-Au(3)-Au(2)
P(3)-Au(3)-Au(4)
170.32(7) Au(1)-Se(1)-Au(2)
96.54(7) C(111)-Se(2)-Au(4) 103.2(3)
91.59(3) C(111)-Se(2)-Au(3) 101.7(3)
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, H, N, and S analyses were carried out with a
Perkin-Elmer 2400 microanalyzer. Mass spectra were recorded on
a VG Autospec, with the liquid secondary-ion mass spectra
(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).
Starting Materials. The starting materials [Au2Cl2(µ-dppf)]22
and [Au(C6F5)3(OEt2)]23 were prepared according to published
procedures. [Au(OTf)(PPh3)] has been obtained by reaction of
[AuCl(PPh3)]24 with Ag(OTf) in dichloromethane and used in situ.
All other reagents were commercially available.
117.98(7) Au(4)-Se(2)-Au(3)
74.62(3)
lower trans influence of the [PhSe]- ligand. The values
compare well with those found in other complexes with a
bridging selenide ligand. Similar Au(III)-Se bond distances
to those in 4 (2.4874(4), 2.4896(4) Å) have been found in
[{Se(AuPPh3)}2{Au(C6F5)2}2]11 (2.4802(8) Å), or in [Se{Au2-
(µ-dppf)}{Au(C6F5)3}]11 (2.5038(13) Å). The gold(I) centers
display distorted linear geometries, whereby the Au(I)-Se
and Au(I)-P bond distances resemble those found in other
selenolato gold complexes.
The structure of complex 5 has been confirmed by X-ray
diffraction of its acetone solvate (Figure 2). Selected bond
lengths and angles are collected in Table 2. The asymmetric
unit consists of two independent formula units, which show
intra- and intermolecular interaction (and also two acetone
molecules); it is analogous to the complex with the thiolate
ligand.16 One discrete cation of 5 consists of two gold cen-
ters doubly bridged by a [PhSe]- ligand and a dppf
diphosphine. The torsion angles in the ferrocene units are
19.5° (C(1)-Cent-Cent-C(7)) and 18.7° (C(61)-Cent-
Cent-C(67)), with the relative phosphorus positions ex-
pressed by P1-Cent-Cent-P2, 89.0°, and P3-Cent-Cent-
P4, -87.7°. The intramolecular Au‚‚‚Au distances in the two
dinuclear units are 3.0193(7) and 2.9839(7) Å, longer than
the intermolecular Au‚‚‚Au distance of 2.9237(7) Å, de-
spite the narrow Au-Se-Au angles of 75.94(3)° and
74.62(3)°. However, in the analogous thiolate complex
[Au2(µ-SC6F5)(µ-dppf)]OTf both intermolecular (2.9610(16)
Synthesis of [Au2(SePh)2(µ-dppf)] (1). To a solution of
[Au2Cl2(µ-dppf)] (0.102 g, 0.1 mmol) in 20 mL of tetrahydrofuran
was added PhSeSiMe3 (0.046 g, 0.2 mmol), and the mixture was
stirred for 1 h. The solution was concentrated to ca. 5 mL, and
then, by addition of diethyl ether (10 mL) an orange solid of 1 was
isolated. Yield 80%. ΛM ) 0.4 Ω-1 cm2 mol-1. Elemental Analysis
(%) Found: C, 43.47; H, 2.89. Calcd for C46H38Au2FeP2Se2: C,
1
43.81; H, 3.01. NMR data. H, δ: 4.14 (m, 4H, C5H4), 4.45 (m,
4H, C5H4), 7.24-7.65 (m, 30H, Ph). 31P(1H), δ: 33.0 (s, 2P, PPh2)
ppm.
(21) Canales, F.; Gimeno, M. C.; Jones, P. G.; Laguna, A. Angew. Chem.,
Int. Ed. Engl. 1994, 33, 769.
(22) Gimeno, M. C.; Laguna, A.; Sarroca, C.; Jones, P. G. Inorg. Chem.
1993, 32, 5926.
(23) Uso´n, A.; Laguna, A.; Laguna, M.; Jime´nez, J.; Durana, M. E. Inorg.
Chim. Acta 1990, 168, 89.
(24) Uso´n, R.; Laguna, A. Inorg. Synth. 1982, 21, 71.
Inorganic Chemistry, Vol. 43, No. 22, 2004 7237

Canales et al.
Table 3. Details of Data Collection and Structure Refinement for
Complexes 4, 5, and 5′
Synthesis of [Au4(µ-SePh)2(PPh3)2(µ-dppf)](OTf)2 (2). To a
solution of [Au2(SePh)2(µ-dppf)] (0.126 g, 0.1 mmol) in 20 mL of
dichloromethane was added [Au(OTf)(PPh3)] (0.122 g, 0.2 mmol),
and the mixture was stirred for 1 h. Concentration of the sol-
vent to ca. 5 mL and addition of diethyl ether (10 mL) gave an
orange solid of 2. Yield 67%. ΛM ) 210 Ω-1 cm2 mol-1. Ele-
mental Analysis (%) Found: C, 40.76; H, 3.17; S, 2.53. Calcd for
C84H68Au4FeO6P4S2Se2: C, 40.71; H, 2.75; S, 2.58. NMR data.
1H, δ: 4.21 (m, 4H, C5H4), 4.56 (m, 4H, C5H4), 7.19-7.69 (m,
60H, Ph). 31P(1H), δ: 33.0 (s, 2P, PPh2), 36.2 (s, 2P, PPh3) ppm.
Synthesis of [Au3(C6F5)3(µ-SePh)2(µ-dppf)] (3). To a solution
of [Au2(SePh)2(µ-dppf)] (0.126 g, 0.1 mmol) in 20 mL of
dichloromethane was added [Au(C6F5)3OEt2] (0.077 g, 0.1 mmol),
and the mixture was stirred for 30 min. Concentration of the solvent
to ca. 5 mL and addition of hexane (10 mL) gave an orange solid
of 3. Yield 62%. ΛM ) 3.4 Ω-1 cm2 mol-1. Elemental Analysis
(%) Found: C, 39.45; H, 2.41. Calcd for C64H38Au3F15FeP2Se2:
C, 39.22; H, 1.95. NMR data. 1H, δ: 4.17 (m, 4H, C5H4), 4.42 (m,
4H, C5H4), 6.71-7.59 (m, 30H, Ph). 31P(1H), δ: 30.5 (s, 2P, PPh2).
19F, δ: -119.2 (m, 4F, o-F), -121.5 (m, 2F, o-F), -160.0 (t, 1F,
4
5
5′
chemical
formula
cryst habit
C
82H38Au4-
30FeP2Se2
pale yellow
hexagonal plate
C44H36Au2F3-
FeO4P2SSe
yellow trapezoidal yellow prism
plate
0.24 × 0.14 ×
0.04
C42.5H36Au2F3-
Cl3FeO3P2SSe
F
cryst size/mm3
0.21 × 0.16 ×
0.40 × 0.16 ×
0.13
0.04
cryst syst
space group
a/Å
b/Å
c/Å
R/deg
â/deg
γ/deg
U/Å3
monoclinic
P21/n
13.2844(11)
21.8735(16)
27.1159(18)
90
96.923(3)
90
7821.8(10)
4
2.256
2656.70
4960
-130
60
monoclinic
P21/c
23.974(4)
13.384(2)
27.686(4)
90
106.126(6)
90
8534(2)
8
2.042
2622.99
5008
-130
52
monoclinic
P21/c
27.294(3)
13.0289(16)
27.574(3)
90
116.23(2)
90
8795.8(18)
8
2.085
1380.81
5256
-130
50
Z
Dc/g cm-3
M
F(000)
T/°C
2θmax/deg
µ(Μo KR)/mm-1 8.747
8.228
71386
8.163
127381
3
p-F, J(FF) 18.0 Hz), -160.7 (m, 2F, p-F), -163.0 (m, 6F, m-F)
ppm.
no. reflns
measured
no. unique reflns 22884
147698
17470
0.1827
0.0490
0.1267
16458
0.1204
0.0606
0.1589
Synthesis of [Au4(C6F5)6(µ-SePh)2(µ-dppf)] (4). To a solution
of [Au2(SePh)2(µ-dppf)] (0.126 g, 0.1 mmol) in 20 mL of
dichloromethane was added [Au(C6F5)3OEt2] (0.154 g, 0.2 mmol),
and the mixture was stirred for 30 min. Concentration of the solvent
to ca. 5 mL and addition of hexane (10 mL) gave an orange solid
of 4. Yield 70%. ΛM ) 4.0 Ω-1 cm2 mol-1. Elemental Analysis
(%) Found: C, 37.45; H, 1.47. Calcd for C82H38Au4F30FeP2Se2:
C, 37.05; H, 1.44. NMR data. 1H, δ: 4.37 (m, 4H, C5H4), 4.71 (m,
4H, C5H4), 6.97-7.56 (m, 30H, Ph). 31P(1H), δ: 32.6 (s, 2P, PPh2).
19F, δ: -122.2 (m, 4F, o-F), -119.1 (m, 8F, o-F), -158.1 (t, 4F,
p-F, 3J(FF) 19.1 Hz), -157.9 (t, 2F, p-F, 3J(FF) 21.0 Hz), -161.9
(m, 4F, m-F), -161.5 (m, 8F, m-F) ppm.
Rint
0.0954
0.0269
0.0503
Ra (F > 4σ(F))
Rwb (F2, all
reflns)
no. reflns used
no. params
no. restraints
Sc
22884
1090
344
0.900
1.240
17470
1052
1069
0.939
1.791
16458
1039
883
1.064
3.552
max ∆F/e Å-3
a R(F)) ∑||Fo| - |Fc||/∑|Fo|. b Rw(F2) ) [∑{w(Fo2 - Fc2)2}/∑{w(Fo2)2}]0.5
;
2
2
2
w-1 ) σ2( Fo ) + (aP)2 + bP, where P ) [Fo + 2Fc ]/3 and a and b are
constants adjusted by the program. c S ) [∑{w(Fo - Fc )2}/(n - p)]0.5
where n is the number of data and p the number of parameters.
,
2
2
Synthesis of [Au2(µ-SePh)(µ-dppf)]OTf (5). To a solution of
[Au2(SePh)2(µ-dppf)] (0.126 g, 0.1 mmol) in 20 mL of dichlo-
romethane was added Ag(OTf) (0.026 g, 0.1 mmol), and the mixture
was stirred for 1 h. The solid [Ag(SePh)]n was filtered off and the
solution concentrated to ca. 5 mL. Addition of diethyl ether (10
mL) afforded an orange solid of 5. Yield 65%. ΛM ) 83 Ω-1 cm2
mol-1. Elemental Analysis (%) Found: C, 39.08; H, 2.73; S, 2.54.
Calcd for C41H33Au2F3FeO3P2SSe: C, 39.26; H, 2.63; S, 2.55. NMR
using a riding model. Special refinement details for 4 follow: One
phenyl ring (C51-56) at Se1 is disordered over two position with
half occupancies. One of the triflate anions is also disordered over
two positions with 0.64 and 0.36 occupancies. Acetone hydrogens
were not located. Further details of the data collection and
refinement are given in Table 3.
Acknowledgment. We thank the Direccio´n General de
Investigacio´n Cient´ıfica y Te´cnica (No. BQU2001-2409-C02-
C01) and the Fonds der Chemischen Industrie for financial
support.
1
data. H, δ: 4.18 (m, 4H, C5H4), 4.55 (m, 4H, C5H4), 7.19-7.60
(m, 25H, Ph). 31P(1H), δ: 31.1 (s, 2P, PPh2).
Crystallography. Crystals were mounted in inert oil on glass
fibers and transferred to the cold gas stream of a Bruker Smart
1000 CCD diffractometer equipped with a low-temperature attach-
ment. Data were collected using monochromated Mo KR radiation
(λ ) 0.71073 Å). Scan type was ω (5) or ω and φ (4, 5′). Absorption
corrections were performed by face indexing (4, 5) or were based
on multiple scans, program SADABS (5′). The structures were
refined on F2 using the program SHELXL-97.25 All non-hydrogen
atoms were refined anisotropically. Hydrogen atoms were included
Supporting Information Available: X-ray crystallographic
files, in CIF format, for complexes 4, 5, and 5′. This material is
available free of charge via the Internet at http://pubs.acs.org.
IC0493806
(25) Sheldrick, G. M. SHELXL-97, Program for Crystal Structure Refine-
ment; University of Go¨ttingen: Go¨ttingen, Germany, 1997.
7238 Inorganic Chemistry, Vol. 43, No. 22, 2004