Luminescent dinuclear gold complexes of bis(diphenylphosphano)acetylene

Article abstract of DOI:10.1016/j.ica.2004.05.017

We have synthesized a series of dinuclear gold(I) derivatives with the diphosphane bis(diphenylphosphano)acetylene, namely [(AuX)₂(μ- dppa)] (X=Cl, C₆F₅, SC₆F₅, S ₂CN(CH₂Ph)

Full text of DOI:10.1016/j.ica.2004.05.017

Inorganica Chimica Acta 358 (2005) 1365–1372
www.elsevier.com/locate/ica
Luminescent dinuclear gold complexes of
bis(diphenylphosphano)acetylene
a
Manuel Bardajı , M. Teresa de la Cruz , Peter G. Jones , Antonio Laguna
c
a,
*
ꢀ a,b
,
a
Julia Martınez , M. Dolores Villacampa
a
ꢀ
a
ꢀ
ꢀ
ꢀ
Departamento de Quımica Inorganica, Facultad de Ciencias, Instituto de Ciencia de Materiales de Aragon, Universidad de Zaragoza-CSIC,
E50009 Zaragoza, Spain
b
Quꢀımica Inorgꢀanica, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid, Spain
c
Institut f€ur Anorganische und Analytische Chemie, Technische Universit€at Braunschweig, Postfach 3329, D-38023 Braunschweig, Germany
Received 2 April 2004; accepted 1 May 2004
Available online 26 June 2004
Dedicated to F. Gordon, A. Stone
Abstract
We have synthesized a series of dinuclear gold(I) derivatives with the diphosphane bis(diphenylphosphano)acetylene, namely
[(AuX)2(l-dppa)] (X ¼ Cl, C6F5, SC6F5, S2CN(CH2Ph)2). X-ray structure determinations for the first three derivatives reveal a
linear geometry for the gold centres. There are no intramolecular gold–gold interactions, although for X ¼ Cl intermolecular
ꢁ
gold(I)–gold(I) interactions of 3.0694(4) A lead to an infinite twisted chain; the further presence of C–Hꢀ ꢀ ꢀCl contacts leads to a
more complex three-dimensional structure. All the derivatives are luminescent in the solid state at low temperature in the range
455–593 nm; most of them are emissive at room temperature in the range 470–598 nm. We have also prepared the dinuclear gold(III)
derivative [(Au(C6F5)3)2(l-dppa)]. Finally, we have prepared the derivative [(AuCl)2(l-dppa)3], which forms a cage with two tet-
rahedrically coordinated gold(I) centres at the apical positions bridged by three rigid diphosphane ligands, with a helical twist of
ꢁ
26.2°, and a gold–gold distance of 5.769 A. The gold(III) and the four-coordinate gold(I) derivatives are not luminescent.
Ó 2004 Elsevier B.V. All rights reserved.
Keywords: Gold; Aurophilicity; Diphosphane ligands; Luminescence
1. Introduction
Diphosphane ligands in gold(I) derivatives can act in
chelating mode, typically [Au(PR2ZPR2)2]þ (Z ¼ CH2,
(CH2)n, NHꢀ ꢀ ꢀ) or in bridging mode; the latter usually
affords dinuclear derivatives, namely [(AuX)2(l-
PR2ZPR2)] and [Au2(l-R2ZPR2)2]2þ [5]. Much less
common is the formation of polymers [{Au(l-PR2-
ZPR2)}n]nþ or even catenanes or metallocryptands [6].
The replacement of a proton by an AuPRþ3 fragment is
a well-established synthetic procedure, which has been
thoroughly used in cluster chemistry [7]. In the same way,
AuPR2ZPR2Au2þ fragments have been used, e.g., the
Au(dppa)Au2þ unit (dppa ¼ bis(diphenylphosphano)-
acetylene) [8] obtained from the chloro derivative [9].
In this paper, we report the synthesis and structural
characterization of a series of dinuclear gold(I) deriva-
tives [(AuX)2(l-dppa)n] (n ¼ 1, 3), which present line-
The vast majority of gold(I) complexes are two-co-
ordinate, linear, 14-electron species, whereas three- and
especially four-coordinate species are less common [1].
Linear gold(I) complexes can group by means of auro-
philic interactions to give supramolecular structures,
such as pairs, rings, chains or layers, which are not
present for the higher coordination numbers [2]. The
aggregation of gold(I) monomers can also be based on
hydrogen bonds [3] or a combination of aurophilic and
hydrogen bonds [4].
* Corresponding author. Tel.: +34-976-761185; fax: +34-976-761187.
E-mail address: alaguna@unizar.es (A. Laguna).
0020-1693/$ - see front matter Ó 2004 Elsevier B.V. All rights reserved.
doi:10.1016/j.ica.2004.05.017

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M. Bardajı et al. / Inorganica Chimica Acta 358 (2005) 1365–1372
1366
arly coordinated gold(I) centres for n ¼ 1. In the case of
X ¼ Cl, a different supramolecular structure is observed
because of aurophilic and hydrogen interactions. For
n ¼ 3, the one structure displays a helical cage with
tetrahedrically coordinated gold(I) centres at the apical
vertices. All the dicoordinated gold(I) complexes are
photoluminescent in the solid state, whereas the tetra-
coordinated gold(I) and gold(III) complexes are not
emissive.
for derivative 1, but not for derivative 6. The 19F NMR
spectra show the presence of one type of pentafluor-
ophenyl gold(I) or tris(pentafluorophenyl)gold(III) units
for complexes 2 or 3, respectively. A singlet is always
observed in the phosphorus spectra, the chemical dis-
placement following the sequence: C6F5 > SC6F5 > Cl >
S2CN(CH2Ph)2 > (C6F5)3 > Cl(dppa)3.
2.2. Crystal structures
The molecular structures of [(AuX)2(l-dppa)], where
X ¼ Cl (1), C6F5 (2), SC6F5 (5), were determined by
X-ray diffraction studies. Compound 5 is a chloroform
solvate. Structural parameters are set out in Table 1.
Despite the similarities in molecular structures, complex
1 displays a more complicated intermolecular organi-
zation. The three dinuclear molecules display crystallo-
graphic inversion symmetry, with the inversion centre
lying at the midpoint of the acetylenic CBC bond. The
gold(I) centres display an almost linear coordination
with P–Au–X angles around 176° (see Fig. 1). There are
no short intramolecular gold–gold contacts, the intra-
molecular gold–gold distance being 7.792 (1), 7.639 (2)
2. Results and discussion
2.1. Synthesis and characterization
As stated in the introduction, complex 1 had been
synthesized in a different way [9]. The reaction of
bis(diphenylphosphano)acetylene with the correspond-
ing gold(I) or gold(III) tht (tht ¼ tetrahydrothiophene)
derivative, in molar ratio 1:2, proceeds by displacing the
tht ligand to give complexes 1–3. Treatment of complex
1 with sodium dithiocarbamate or thiolate leads to de-
rivatives 4–5, by means of a substitution reaction. The
reaction of the diphosphane with AuCl(tht) in a 3:2
molar ratio affords complex 6, which can be also syn-
thesized by reaction of diphosphane and complex 1 (see
Scheme 1). The addition of an excess of diphosphane
and work-up, as described in the Section 4, leads to the
isolation of derivative 6. However, in situ addition of
diphosphane to [AuCl(tht)], monitored by phosphorus
NMR at low temperature, leads to complex 6, but when
more diphosphane is added the spectrum shows com-
plicated mixtures containing free phosphane arms cou-
pled to coordinated phosphane arms. The reaction
of diphosphane and [AuCl(tht)] in molar ratio 1:1 al-
lows the isolation of a product with stoichiometry
[(AuCl)2(l-dppa)2], but the phosphorus NMR spectrum
at low temperature shows a mixture of 1 and 6.
ꢁ
and 7.412 A (5) because of the trans conformation of the
diphosphane, which is preferred to minimize steric hin-
drance; besides, a cis conformation would not lead to
gold–gold interactions because of the long and rigid
bridge. The Au–P distance displays a trans influence
in the sequence Cl < SC6F5 < C6F5. The Au–Cl distance
ꢁ
in 1 of 2.2928(11) A compares well with those reported
ꢁ
in [AuCl(PPh2CH2SiMe3)] (2.292(2) A) [10] or in
ꢁ
[AuCl(PPh2CCH)] (2.2892(12) A) [11]. The Au–C bond
ꢁ
length in 2 is 2.045(8) A, similar to those found in
[Au(C6F5)(PPh2CCH)] [11] or in [(AuC6F5)2(l-dppm)]
Table 1
ꢁ
Selected bond lengths (A) and angles (°) for compound 1, 2 and 5
Compound 1
Au–P
These complexes are air- and moisture-stable white or
yellow (4) solids at room temperature. They were readily
characterized by elemental analysis, IR and NMR spec-
troscopies. IR spectra show the presence of Au–Cl bonds
2.2354(10) P–Au–Cl
2.2928(11) P–Au–Au#1
175.20(4)
107.32(3)
77.47(3)
177.8(5)
Au–Cl
Au–Au#1
C(1)–C(1)#2
3.0694(4)
1.200(8)
Cl–Au–Au#1
C(1)#2–C(1)–P
Compound 2
Au–C(31)
Au–P
X'
X
2.045(8)
2.2713(19)
C(1)–C(1)#1
1.200(16)
176.1(10)
Au
Au
Ph2PC CPPh2
Au
ii
Ph PC CPPh2
2
C(31)–Au–P
175.8(2)
C(1)#1–C(1)–P
Au
Compound 5
Au–P
Au–S
X = Cl 1, C6F5 2,
(C6F5)3
X'
X' = S2CN(CH2Ph)2 4,
SC6F5
X
2.2483(7)
2.3193(7)
1.209(5)
5
3
iii
C(1)–C(1)#1
P–Au–S
i
175.94(2)
107.62(10)
174.0(3)
C(11)–S–Au
C(1)#1–C(1)–P
iv
[Au2Cl2 (Ph2PC CPPh2)3]
Ph2PC CPPh2
Symmetry transformations used to generate equivalent atoms: #1
ꢁx þ 1; y; ꢁz þ 1=2; #2 ꢁx þ 1; ꢁy þ 2; ꢁz þ 1 (compound 1), #1
ꢁx þ 1; ꢁy þ 1; ꢁz þ 2 (compound 2), #1 ꢁx þ 1; ꢁy þ 1; ꢁz (com-
pound 5).
6
Scheme 1. (i) +2[AuX(tht)] ) 2tht; (ii) +2NaX0 ) 2NaX; (iii)
+2PPh2CCPPh2; (iv) +2/3[AuCl(tht)] ) 2/3tht.

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1367
ular gold–gold contacts in the absence of intramolecular
gold-gold contacts is less common in diphosphano-
gold(I) derivatives and has usually been observed for di-
phosphanes bridged by longer carbon chains, such as
PPh2(CH2)nPPh2 n ¼ 3 [13], 5 [6c,14], 8 [15], and for
bis(diphenylphosphano)ethene [6d,16]. A similar infinite
chain, arising from aurophilic interactions, has been
observed for [(AuSPh)2(l-PPh2CH@CHPPh2)] and
[(AuCl) (AuSPh)(l-PPh2CH@CHPPh2)] [16]. In addi-
tion, complex 1 displays several C–Hꢀ ꢀ ꢀCl contacts, one
particularly short, that could be interpreted as hydrogen
bonds (Table 2). These interactions connect the chains.
This is an example of a cooperative effect of aurophilic
interactions and hydrogen bonds to give a supramolecu-
lar structure. In compound 5, the chloroform molecule,
although disordered over an inversion centre, is hydrogen
bonded to one or the other of two sulfur atoms, with
Fig. 1. Molecular structure of complex 2.
ꢁ
[12]. The Au–S bond length in 5 is 2.3193(7) A, close to
those reported in thiolato-phosphano gold(I) complexes.
The acetylenephosphano ligand shows almost linear
angles P–C–C, from 174.0(3)° in complex 5 to 177.8(5)°
in complex 1. The central C–C distances of around
1.200 A are consistent with a triple bond.
As stated above, derivatives 2 and 5 are discrete
molecules whilst derivative 1 shows intermolecular
ꢁ
Hꢀ ꢀ ꢀS 2.87 A, C–Hꢀ ꢀ ꢀS 168°.
The crystal structure of complex 6 [(AuCl)2(l-dppa)3]
is shown in Fig. 3, with selected bond lengths and angles
in Table 3. Compound 6 is a monohydrate. The struc-
ture shows a cage capped by two chlorine atoms and two
gold atoms triply bridged by the dppa ligands. The
gold(I) centres are four-coordinate and display a dis-
torted tetrahedral environment with P–Au–P and P–
Au–Cl angles lying in the range 102.87(3)–122.99(3)°.
ꢁ
ꢁ
gold(I)–gold(I) interactions of 3.0694(4) A via a twofold
axis, leading to an infinite twisted chain with a ladder-like
form in projection (Fig. 2). The existence of intermolec-
Fig. 3. Molecular structure of complex 6. Phenyl rings and hydrogen
atoms have been omitted for clarity.
Fig. 2. View of the chain of complex 1.
Table 2
ꢁ
Hydrogen bonds for compound 1 and 6 (A) and (°)
D–Hꢀ ꢀ ꢀA
Compound 1
d(D–H)
d(Hꢀ ꢀ ꢀA)
d(Dꢀ ꢀ ꢀA)
\(DHA)
C(25)–H(25)ꢀ ꢀ ꢀCl#3
C(14)–H(14)ꢀ ꢀ ꢀCl#4
C(15)–H(15)ꢀ ꢀ ꢀCl#4
0.95
0.95
0.95
2.76
2.92
2.95
3.664(5)
3.563(5)
3.577(5)
160.1
126.5
124.5
Compound 6
C(43)–H(43)ꢀ ꢀ ꢀCl(1)#1
C(84)–H(84) Cl(2)#2
O(1)–H(1)ꢀ ꢀ ꢀCl(1)
O(1)–H(2)ꢀ ꢀ ꢀCl(2)#3
0.93
0.93
2.86
2.80
3.551(3)
3.580(3)
3.330(3)
3.239(3)
131.9
142.5
1.077(4)
0.903(4)
2.42(4)
2.38(4)
141.8(3)
158.6(4)
Symmetry transformations used to generate equivalent atoms: #3 ꢁx þ 1=2; y þ 1=2; ꢁz þ 1=2; #4 x; y; z þ 1 (compound 1), #1
x ꢁ 1=2; ꢁy þ 3=2; z ꢁ 1=2; #2 x þ 1=2; ꢁy þ 3=2; z þ 1=2; #3 x ꢁ 1=2; ꢁy þ 3=2; z þ 1=2 (compound 6).

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M. Bardajı et al. / Inorganica Chimica Acta 358 (2005) 1365–1372
1368
ꢁ
than in [{(AuCl)2(l-L)}n] (3.012(6) A) [20]. This long (and
presumably weak) bond should explain why the Au–Cl
vibration is not observed by IR spectroscopy. Addition-
ally, complex 6 displays two classical hydrogen bonds of
Table 3
ꢁ
Selected bond lengths (A) and angles (°) for compound 6
Au(1)–P(5)
Au(1)–P(1)
Au(1)–P(4)
Au(1)–Cl(1)
Au(2)–P(2)
Au(2)–P(6)
2.3424(8)
2.3721(8)
2.4068(8)
2.6399(8)
2.3412(8)
2.3659(8)
Au(2)–P(3)
2.3660(8)
2.6378(8)
1.191(4)
1.194(4)
1.200(4)
Au(2)–Cl(2)
C(27)–C(28)
C(67)–C(68)
C(107)–C(108)
ꢁ
the form Clꢀ ꢀ ꢀH–O (water) (Hꢀ ꢀ ꢀCl1 2.42 A and
ꢁ
O–Hꢀ ꢀ ꢀCl1 142°; Hꢀ ꢀ ꢀCl2 2.38 A and O–Hꢀ ꢀ ꢀCl2 159°).
2.3. Photophysical studies
P(5)–Au(1)–P(1)
P(5)–Au(1)–P(4)
P(1)–Au(1)–P(4)
P(5)–Au(1)–Cl(1)
P(1)–Au(1)–Cl(1)
P(4)–Au(1)–Cl(1)
P(2)–Au(2)–P(6)
P(2)–Au(2)–P(3)
P(6)–Au(2)–P(3)
122.99(3)
112.36(3)
103.76(3)
107.45(3)
103.36(3)
105.38(3)
117.34(3)
118.58(3)
107.30(3)
P(2)–Au(2)–Cl(2)
P(6)–Au(2)–Cl(2)
P(3)–Au(2)–Cl(2)
C(28)–C(27)–P(1)
C(27)–C(28)–P(2)
C(68)–C(67)–P(3)
C(67)–C(68)–P(4)
105.09(3)
102.87(3)
103.48(3)
172.1(3)
170.2(3)
171.1(3)
173.1(3)
The absorption spectra in dichloromethane were
measured in the range 200–600 nm and the results are
summarized in Table 4. All the spectra are dominated by
an absorption around 230 nm from the phenyl phos-
phane rings [21]. There is also an absorption around 277
nm, which is already observed in the diphosphane li-
gand, and it could be assigned to a p–pꢂ transition, al-
though this could be complicated by transitions of the
pentafluorophenyl or thiolate ligands in derivatives 2–5.
The thiolato derivatives 4–5 also display an intense ab-
sorption at 300 nm, which could be related to sulfur to
gold charge transfer transitions [22].
We have studied the photoluminescence of these
products in the solid state and the results are summa-
rized in Table 5. Emission spectra of derivatives 1, 4 and
5 at low temperature are plotted in Fig. 4. Derivatives 1,
2 and 4 emit weakly at room temperature, whereas they
and derivative 5 emit intensely at 77K; the diphosphane
does not emit under the same conditions. The cooling
produces a 701 cmꢁ1 blue shift in the emission of com-
plex 1, a 476 cmꢁ1 red shift for 2 and a 141 cmꢁ1 blue
shift in the emission of complex 4. Only complex 1 has
gold–gold interactions in the solid state and therefore, to
explain the luminescence of complexes 1 and 2, a ligand-
centred transition modified by the anionic ligands and
the gold(I) centres can be suggested, as has been already
proposed for the series [{AuXPPhMe2}n] (X ¼ Cl, Br, I;
n ¼ 2, 3) or [AuX(ER3)] (X ¼ Cl, Br; E ¼ P, As) [23];
however, a metal–metal centred transition, as suggested
for most luminescent diphosphane gold(I) complexes,
could also be possible for complex 1 [24]. The emission
observed for thiolato derivatives 4–5 is usually assigned
to a thiolato to gold charge transfer transition, which is
changed by varying the nature of the substituents of the
thiolate ligand [25].
C(108)–C(107)–P(5) 170.0(3)
C(107)–C(108)–P(6) 171.7(3)
ꢁ
The intramolecular gold–gold distance is 5.769 A and
the tetracoordination prevents any intermolecular gold–
gold interaction. The three acetylenephosphane bridges
display P–C–C angles lying in the range 170.0(3)–
173.1(3)°, slightly bent compared to those of complexes
1, 2 and 5 and C–C triple bond lengths in the range
ꢁ
1.191(4)–1.200(4) A, similar to the above structures. The
cage shows a helical twist of 26.2°, about the Auꢀ ꢀ ꢀAu
axis, calculated as the average of the torsion angles
P(1)–Au(1)–Au(2)–P(2), P(3)–Au(2)–Au(1)–P(4) and
P(5)–Au(1)–Au(2)–P(6). This structure is close to those
reported for silver(I) complexes with the same diphos-
phane, namely [Ag2(l-dppa)3(anion)2] (anion ¼ SbF6,
BF4, O3SCF3 or NO3), where silver centres have a tri-
gonal geometry but tetrahedrically distorted because of
Ag–anion contacts and a helical twist of 33°, 27°, 35.3°
and 28.6°, respectively [17]. The related copper complex
[(CuTenBu)2(l-dppa)3] also presents a helical twist of
23.6° and a similar structure to complex 6 [18]. How-
ever, the related structure [(AuI)2(l-P2pz)3] (P2pz ¼ 3,6-
bis(diphenylphosphano)pyridazine) does not show this
helical twist and crystallizes in a hexagonal space group
with only one-sixth of the molecule being crystallo-
graphically unique [6g].
The Au–P bond lengths range from 2.3412(8) to
ꢁ
2.4068(8) A, much longer than those found in the two-
coordinate complexes 1, 2 and 5, but in a similar range to
those reported in other four-coordinate complexes such
Table 4
Electronic absorption data for complexes 1–6a
ꢁ
as [AuCl(PPh3)3] (2.395(2)–2.431(2) A) [19], [{(AuCl)2(l-
L
)}n] (
L
¼ p-tert-butyl-calix[4]-(OCH2PPh2)4; 2.371(2)–
Complex
k (nm) (e/Mꢁ1 cmꢁ1
)
ꢁ ꢁ
2.384(2) A) [20], [{(AuCl)2(l-P2pz)3}n] (2.3683(6) A) [6g]
and in the similar cage structure [(AuI)2(l-P2pz)3]
(2.417(4) A) [6g]. The Au–Cl distances of 2.6378(8) and
PPh2CCPPh2
230 (31800), 244 (30100), 277 (sh, 9500)
230 (51600), 270 (sh, 8170), 277 (sh, 5840)
233 (70100), 258 (sh, 71410), 277 (sh, 7400)
229 (71800), 277 (34560)
1
2
3
4
5
6
ꢁ
ꢁ
2.6399(8) A are clearly longer than standard covalent
Au(I)–Cl bond lengths in two-coordinate derivatives, as
ꢁ
found in complex 1 (2.2928(11) A), although slightly
231 (66400), 277 (48140), 295 (sh, 37640)
233 (79550), 268 (sh, 31440), 301 (sh, 13570)
234 (117660), 267 (sh, 42250), 276 (sh, 31080)
ꢁ
shorter than reported in [AuCl(PPh3)3] (2.710(2) A) [19],
[{(AuCl)2(l-P2pz)3}n] (2.7026(10) A) [6g] and shorter
a In CH2Cl2 solution, 5 ꢃ 10ꢁ5 M.
ꢁ

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1369
4000–200 cmꢁ1, by using Nujol mulls between polyeth-
Table 5
Excitation and emission data in the solid state for luminescent com-
plexes 1–2 and 4–5
1
ylene sheets or KBr pellets. H, 19F and 31P{1H} NMR
spectra were recorded on a Bruker ARX ꢀ 300 or
298 K
77 K
Complex
GEMINI 2000 apparatus; chemical shifts are quoted
1
relative to SiMe4 (external, H), CFCl3 (external, 19F)
kexc (nm)
kemis (nm)
kexc (nm)
kemis (nm)
and 85% H3PO4 (external, 31P). C, H, N and S analyses
were performed with a Perkin–Elmer 2400 microana-
lyzer. The luminescence spectra were recorded on a
Perkin–Elmer LS-55 spectrofluorometer. UV–Vis ab-
sorption spectra in dichloromethane solution were re-
corded at 298 K on a Shimadzu UV-1603.
1
2
4
5
309
370
470
516
598
304
355
455
529
593
551
457, 467
458, 465
355, 393
800
700
600
500
4.2. Preparation of [(AuX)2(l-dppa)] X ¼ Cl (1), C6F5
(2), (C6F5)3 (3)
To a 30 mL dichloromethane solution of [AuX(tht)]
(tht ¼ tetrahydrothiophene; X ¼ Cl, 0.4 mmol 128 mg;
C6F5 0.2 mmol, 90 mg) [26,27] or [Au(C6F5)3(tht)]
(157 mg, 0.2 mmol) [26] was added bis(diphenylphos-
phane)acetylene (78 mg, 0.2 mmol for X ¼ Cl; 39 mg,
0.1 mmol). After stirring for 1 h, derivative 1 was filtered
off as a white powder. The solution was concentrated to
ca. 3 mL and further addition of hexane afforded com-
plexes 1 (second fraction), 2 and 3 as white solids. Yield
400
300
200
100
400
450
500
550
600
650
700
1
of 1: 90%. H NMR (300 MHz, CDCl3, 21 °C): d 7.47–
Wavelength (nm)
7.79 (m, Ph); 31P{1H} NMR (121 MHz, CDCl3, 21 °C):
d 5.5 (s). 31P{1H} NMR (ꢁ50 °C): d 5.1 (s). IR: 326 (m,
Fig. 4. Emission spectra of derivatives 1 (—), 4 (- -) and 5 (– –) at low
temperature in the solid state.
m(Au–Cl)) cmꢁ1
C26H20Au2Cl2P2 requires: C, 36.35; H, 2.35%. Yield of
.
Found: C, 36.1; H, 2.25%.
2: 83%. IR: 955, 785 (s, C6F5) cmꢁ1
.
1H NMR (300
1
3. Conclusions
MHz, CDCl3, 21 °C): d 7.29–7.79 (m, Ph); F NMR
(282 MHz, CDCl3, 21 °C): d-117.1 (m, 2Fo), )158.7 (t,
3JFF ¼ 20.0 Hz, 1Fp), )163.2 (m, 2Fm); 31P{1H} NMR
(121 MHz, CDCl3, 21 °C): d 18.4 (s). Found: C, 40.35;
H, 2.0%. C38H20Au2F10P2 requires: C, 40.65; H, 1.8%.
We have shown that dinuclear derivatives [(AuX)2(l-
dppa)] (X ¼ Cl, C6F5, S2CN(CH2Ph)2, SC6F5) contain-
ing a rigid PCCP unit can be found as monomers
without any obvious intra- or intermolecular interac-
tions, but also be linked to a chain and then to a three-
dimensional structure by intermolecular gold(I)–gold(I)
and hydrogen bonding interactions, as has been re-
ported for diphosphano-gold(I) derivatives with long
alkyl chain bridges. Additionally, the use of this rigid
diphosphane allows us to prepare [(AuCl)2(l-dppa)3] as
a helical twisted cage, with two tetrahedrically coordi-
nated gold(I) centres at the apical positions bridged by
three diphosphane ligands. Most of these complexes are
photoluminescent.
Yield of 3: 76%. IR: 969, 793 (s, C6F5) cmꢁ1. H NMR
1
(300 MHz, CDCl3, 21 °C): d 7.43–7.79 (m, Ph); 1F
NMR (282 MHz, CDCl3, 21 °C): d )121.4 (m, 4Fo),
3
)122.8 (m, 2Fo), )156.2 (t, JFF ¼ 20.1 Hz, 2Fp),
)157.2 (t, 3JFF ¼ 20.1 Hz, 1Fp), )161.0 (m, 4Fm), )161.7
(m, 2Fm); 31P{1H} NMR (121 MHz, CDCl3, 21 °C): d
)1.1 (s). Found: C, 41.75; H, 1.25%. C62H20Au2F30P2
requires: C, 41.6; H, 1.15%.
4.3. Preparation of [{Au(S2CN(CH2Ph)2)}2(l-dppa)]
(4)
To a dichloromethane suspension (20 mL) of 1
(86 mg, 0.1 mmol) was added NaS2CN(CH2Ph)2
(0.2 mmol, 59 mg). The mixture was stirred for about
2 h, then filtered through celite. Concentration to ca.
2 mL and addition of hexane (20 mL) afforded complex
4. Experimental
4.1. General procedures
All the reactions were carried out under an argon
atmosphere at room temperature. IR spectra were re-
€
corded on a Perkin–Elmer Spectrum One and a Brucker
Equinox 55 spectrophotometers, over the range
4 as a yellow solid. Yield: 67%. IR: 1494 (s, C@N) cmꢁ1
.
1H NMR (300 MHz, CDCl3, 21 °C): d 7.37–7.86
(m, 40H, Ph), 5.15 (s, 8H, CH2–N); 31P{1H} NMR
(121 MHz, CDCl3, 21 °C): d 3.1 (s). Found: C, 50.25; H,

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M. Bardajı et al. / Inorganica Chimica Acta 358 (2005) 1365–1372
1370
3.55; N, 2.0; S, 9.3%. C56H48Au2N2P2S4 requires: C,
50.45; H, 3.65; N, 2.1; S, 9.6%.
)164.2 (m, 2Fm); 31P{1H} NMR (121 MHz, CDCl3,
21 °C): d 11.1 (s). Found: C, 38.15; H, 1.7; S, 5.0%.
C38H20Au2F10P2S2 requires: C, 38.45; H, 1.7; S, 5.4%.
4.4. Preparation of [{Au(SC6F5)}2(l-dppa)] (5)
4.5. Preparation of [(AuCl)2(l-dppa)3] (6)
To a dichloromethane suspension (20 mL) of 1
(86 mg, 0.1 mmol) was added a methanol solution
(10 mL) of NaSC6F5 (0.2 mmol, prepared in situ with
HSC6F5 and NaOMe). The mixture was stirred for
about 2 h, then evaporated to dryness. Extraction with
dichloromethane, concentration to ca. 3 mL and addi-
tion of hexane (20 mL) afforded complex 5 as a white
solid. Yield: 67%. 1H NMR (300 MHz, CDCl3, 21 °C): d
This derivative has been obtained by two ways: (a) to
a 40 mL dichloromethane solution of [AuCl(tht)]
(100 mg, 0.31 mmol) was added bis(diphenylphos-
phane)acetylene (185 mg, 0.47 mmol). After stirring for
1 h, the solution was concentrated to ca. 5 mL and
addition of hexane afforded complex 6 as a white solid.
(b) To a 20 mL dichloromethane suspension of 1 (86 mg,
0.1 mmol) was added bis(diphenylphosphane)acetylene
(79 mg, 0.2 mmol). The solid dissolved rapidly and the
1
7.49–7.79 (m, Ph); F NMR (282 MHz, CDCl3, 21 °C):
3
d )132.7 (m, 2Fo), )162.2 (t, JFF ¼ 20.3 Hz, 1Fp),
Table 6
Details of crystal data and structure refinement for complexes 1, 2, 5 and 6
Compound
1
2
5 ꢀ CHCl3
C39H21Au2Cl3F10P2S2
6 ꢀ H2O
C78H62Au2Cl2OP6
Empirical formula
Formula weight
Temperature (K)
C26H20Au2Cl2P2
859.19
133(2)
C38H20Au2F10P2
1122.41
143(2)
1305.90
133(2)
1665.93
100(2)
ꢁ
Wavelength (A)
0.71073
monoclinic
C2=c
0.71073
triclinic
0.71073
triclinic
0.71073
monoclinic
P21=n
Crystal system
Space group
Unit cell dimensions
ꢂ
ꢂ
P1
P1
ꢁ
a (A)
16.4410(11)
15.4767(11)
11.1496(8)
90
8.123(2)
10.452(2)
8.2842(6)
12.9807(7)
22.1607(11)
24.0781(12)
ꢁ
b (A)
11.2977(8)
11.9184(8)
73.955(4)
ꢁ
c (A)
11.939(3)
67.509(6)
a (°)
b (°)
c (°)
117.694(4)
90
73.321(6)
75.263(6)
885.1(4)
69.751(4)
76.611(4)
96. 8070(10)
3
ꢁ
Volume (A )
2512.0(3)
4
2.272
994.28(12)
1
2.181
6877.5(6)
4
1.609
Z
1
2.106
Dcalc (mg mꢁ3
)
Absorption coefficient (mmꢁ1
F ð000Þ
)
12.020
1592
8.449
526
7.834
616
4.524
3280
Crystal size (mm)
Diffractometer
0.20 ꢃ 0.09 ꢃ 0.09
Bruker SMART 1000
CCD
0.25 ꢃ 0.18 ꢃ 0.03
Bruker SMART 1000
CCD
0.2 ꢃ 0.2 ꢃ 0.1
Bruker SMART 1000
CCD
0.24 ꢃ 0.24 ꢃ 0.20
Bruker SMART APEX
CCD
h Range data collection
Index ranges
1.92–30.01°
ꢁ22 ꢄ h ꢄ 23,
ꢁ21 ꢄ k ꢄ 21,
ꢁ15 ꢄ l ꢄ 15
22565
1.89–28.28°
ꢁ10 ꢄ h ꢄ 10,
ꢁ13 ꢄ k ꢄ 13,
ꢁ15 ꢄ l ꢄ 15
8772
1.86–30.03°
ꢁ11 ꢄ h ꢄ 11,
ꢁ15 ꢄ k ꢄ 15,
ꢁ16 ꢄ l ꢄ 16
19847
1.25–28.46°
ꢁ17 ꢄ h ꢄ 17
ꢁ28 ꢄ k ꢄ 29
ꢁ31 ꢄ l ꢄ 31
62275
Reflections collected
Independent reflections [Rint
]
3662 [0.0389]
99.9
4313 [0.0709]
98.2
5785 [0.0238]
99.4
16175 [0.0376]
93.1
Completeness to h (max) (%)
Absorption correction
semi-empirical from
equivalents
Maximum and minimum transmission 0.604 and 0.293
semi-empirical from
equivalents
0.962 and 0.485
semi-empirical from
equivalents
0.584 and 0.391
semi-empirical from
equivalents
1.00000 and 0.876101
Refinement method
full-matrix least-squares full-matrix least-squares full-matrix least-squares full-matrix least-squares
on F 2
16175/0/808
on F 2
3662/40/145
on F 2
4313/72/235
on F 2
5785/6/275
Data/restraints/parameters
Goodness-of-fit on F 2
1.223
0.972
1.040
0.866
Final R indices [I > 2rðIÞ]
R1 ¼ 0:0257a,
wR2 ¼ 0:0643b
R1 ¼ 0.0288a,
wR2 ¼ 0.0651b
R1 ¼ 0:0520a,
wR2 ¼ 0:1192b
R1 ¼ 0.0683a,
wR2 ¼ 0.1254b
4.418 and )4.492
R1 ¼ 0:0214a,
wR2 ¼ 0:0554b
R1 ¼ 0.0242a,
wR2 ¼ 0.0562b
1.759 and )0.821
R1 ¼ 0:0271a,
wR2 ¼ 0.0472b
R1 ¼ 0.0362a,
wR2 ¼ 0.0485b
1.403 and )0.644
R indices (all data)
3
ꢁ
Largest difference peak and hole (e A ) 1.670 and )2.023
P
P
a R1ðF Þ ¼ jF j ꢁ jFcj= jFoj.o.
h o n
n
oi
0:5
P
P
2
2
2
b wR2ðF 2Þ ¼
wðFo2 ꢁ Fc2Þ
wðFo2Þ
; wꢁ1 ¼ r2ðFo2Þ þ ðaPÞ þ bP, where P ¼ ðFo2 þ 2Fc2Þ=3 and a and b are constants adjusted by the
program.

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M. Bardajı et al. / Inorganica Chimica Acta 358 (2005) 1365–1372
1371
resulting solution was stirred for 1 h, concentrated to
1
[2] H. Schmidbaur, Gold Bull. 33 (2000) 3.
[3] B. Ahrens, S. Friedrichs, R. Herbst-Irmer, P.G. Jones, Eur. J.
Inorg. Chem. (2000) 2017, and references therein.
[4] (a) W.J. Hunks, M.C. Jennings, R.J. Puddephatt, Inorg. Chem. 41
(2002) 4590;
ca. 3 mL and precipitated with hexane. Yield: 90%. H
NMR (300 MHz, CDCl3, 21 °C): d 7.12–7.71 (m, Ph);
31P{1H} NMR (121 MHz, CDCl3, 21 °C): d )7.3 (br).
31P{1H} NMR ()50 °C): d )5.55 (s). Found: C, 56.65;
H, 3.65%. C78H60Au2Cl2P6 requires: C, 56.85; H, 3.65%.
(b) B.-C. Tzeng, A. Schier, H. Schmidbaur, Inorg. Chem. 38
(1999) 3978;
(c) C. Hollatz, A. Schier, H. Schmidbaur, J. Am. Chem. Soc. 119
(1997) 8115.
4.6. Crystal structure determinations
[5] A. Laguna, in: H. Schmidbaur (Ed.), Gold: Progress in Chemistry,
Biochemistry and Technology, Wiley, Chichester, 1999, pp. 349–
427.
Crystal data and refinement details are given in
Table 6. Single crystals of [(AuCl)2(l-dppa)],
[6] (a) Z. Qin, M.C. Jennings, R.J. Puddephatt, Chem. Eur. J. 8
(2002) 723;
[(AuC6F5)2(l-dppa)],
[(Au(SC6F5))2(l-dppa)]
and
(b) C.P. McArdle, M.J. Irwin, M.C. Jennings, J.J. Vittal, R.J.
Puddephatt, Chem. Eur. J. 8 (2002) 735;
[(AuCl)2(l-dppa)3] were obtained by slow diffusion at
)18 °C, of hexane/ethanol into a dichloromethane/
chloroform solution, of diethyl ether into a dichlorom-
ethane solution, of petroleum ether into a dichlorome-
(c) M.C. Brandys, R.J. Puddephatt, Chem. Commun. (2001) 1280;
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4839;
thane/chloroform solution, of hexane into
a
dichloromethane solution, respectively. The structures
were refined anisotropically on F2 (program SHELXL 97)
[28] using a system of restraints (to light-atom U values
and local ring symmetry). All non-hydrogen atoms were
refined anisotropically. Hydrogen atoms were included
using a riding model. Special features of refinement: the
chloroform molecule of 5 is disordered over an inversion
centre. The water molecule of 6 (O(1), H(1) and H(2))
was located from difference Fourier maps. Oxygen atom
was refined with anisotropic displacement parameters
and hydrogen atoms were refined with isotropic dis-
placement parameters 1.2 times the isotropic equivalent
of oxygen atom.
(f) J.H.K. Yip, J. Prabhavathy, Angew. Chem. Int. Ed. 40 (2001)
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[12] P.G. Jones, C. Thone, Acta Crystallogr., Sect. C 48 (1992) 1312.
€
Complete X-ray data (excluding structure factors) for
complexes 1, 2, 5 and 6 have been deposited with the
Cambridge Crystallographic Data Centre as supple-
mentary publication nos. CCDC-231716-231719. These
data can be obtained free of charge at www.ccdc.ca-
m.ac.uk/conts/retrieving.htlm [or from the Cambridge
Crystallographic Data Centre, 12 Union Road, Cam-
bridge CB2 1EZ, UK; fax: (internat.) +44-1223-336033;
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ꢀ
ꢀ
We thank the Direccion General de Investigacion
ꢀ
ꢀ
Cientıfica y Tecnica (project BQU2001-2409-C02-01)
and the Fonds der Chemischen Industrie for financial
support.
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