Effect of the organic fragment on the mesogenic properties of a series of organogold(I) isocyanide complexes. X-ray crystal structure of [Au(C≡CC5H4N)(CNC6H4O(O) CC6H4OC10H21)]

Article abstract of DOI:10.1016/j.jorganchem.2005.02.043

Rod-like organogold(I) complexes [AuR(CNC₆H₄O(O) CC₆H₄OC₁₀H₂₁-p)] were prepared and their liquid crystal behaviour was studied. Depending on the nature of R, the synthetic methodology was different. Thus, for R = substituted alkynyl ligands, the new compounds were prepared in two steps:(i) reaction of [AuCl(tht)] (tht = tetrahydrothiophene) with R′CCH(R′ = C₅H₄N, C₆H₄CN, C₆H₄CCC₅H ₄N) in the presence of NaOAc to give insoluble [Au(CCR′)] _n; (ii) reaction of the latter polymers with the isonitrile CNC ₆H₄O(O)CC₆H₄OC₁₀H ₂₁-p.For R = fluorinated aryls, the complexes were prepared by displacement of tht from the compounds [AuR(tht)] (R = C₅F ₄N, C₆F₄C₅H₄N, C ₆F₅) with isonitrile.In addition, an unexpected ionic derivative [Au(CCC₅H₄NC₁₀H₂₁) ₂][Au(CCC₅H₄N)₂] was formed in the reaction between [PPh₄][Au(CCC₅H₄N) ₂] and C₁₀H₂₁I. All these compounds have been characterized by IR and NMR spectroscopy and mass spectrometry. The X-ray crystal structure of the compound with R = CCC₅H₄N shows a linear molecule in which the gold atom is surrounded by the pyridine-containing acetylene and the isonitrile ligand, and no direct gold-gold interaction occurs. Six of the neutral compounds are liquid crystals and their optical, thermal and thermodynamic data were analyzed and compared in terms of molecular polarizability.

Full text of DOI:10.1016/j.jorganchem.2005.02.043

Journal of Organometallic Chemistry 690 (2005) 2200–2208
www.elsevier.com/locate/jorganchem
Effect of the organic fragment on the mesogenic properties
of a series of organogold(I) isocyanide complexes. X-ray crystal
structure of [Au(C„CC5H4N)(CNC6H4O(O)CC6H4OC10H21)]
a,
a
Montserrat Ferrer , Mounia Mounir , Laura Rodrıguez , Oriol Rossell ,
a
a
*
´
Silverio Coco , Pilar Gomez-Sal , Avelino Martın
b
c
c
´
´
a
´
Departament de Quımica Inorganica, Universitat de Barcelona, c/ Martı i Franques 1-11, 08028 Barcelona, Spain
´
`
`
b
´ `
Departamento de Quımica Inorganica, Facultad de Ciencias, Universidad de Valladolid, 47005 Valladolid, Spain
´
c
´ ´ ´
Departamento de Quımica Inorganica, Campus Universitario-Edificio de Farmacia, Universidad de Alcala, 28871 Alcala de Henares, Spain
Received 17 January 2005; revised 15 February 2005; accepted 16 February 2005
Abstract
Rod-like organogold(I) complexes [AuR(CNC6H4O(O)CC6H4OC10H21-p)] were prepared and their liquid crystal behaviour was
studied. Depending on the nature of R, the synthetic methodology was different. Thus, for R = substituted alkynyl ligands, the new
compounds were prepared in two steps:(i) reaction of [AuCl(tht)] (tht = tetrahydrothiophene) with R0C„CH(R0 = C5H4N,
C6H4C„N, C6H4C„CC5H4N) in the presence of NaOAc to give insoluble [Au(C„CR0)]n; (ii) reaction of the latter polymers with
the isonitrile CNC6H4O(O)CC6H4OC10H21-p.For R = fluorinated aryls, the complexes were prepared by displacement of tht from
the compounds [AuR(tht)] (R = C5F4N, C6F4C5H4N, C6F5) with isonitrile.In addition, an unexpected ionic derivative
[Au(C„CC5H4NC10H21)2][Au(C„CC5H4N)2] was formed in the reaction between [PPh4][Au(C„CC5H4N)2] and C10H21I. All
these compounds have been characterized by IR and NMR spectroscopy and mass spectrometry. The X-ray crystal structure of
the compound with R = C„CC5H4N shows a linear molecule in which the gold atom is surrounded by the pyridine-containing
acetylene and the isonitrile ligand, and no direct gold–gold interaction occurs. Six of the neutral compounds are liquid crystals
and their optical, thermal and thermodynamic data were analyzed and compared in terms of molecular polarizability.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Organogold compounds; Isocyanide; Liquid crystals; Alkynyl ligand; Fluoroaryl ligand
1. Introduction
ber of gold acetylide compounds have been shown to be
excellent precursors for species showing liquid crystal
behaviour because of the linear shape of the
MAC„CAR moiety and the lack of b-hydrogen atoms
in the MAC„C bond [4]. Looking at this second point,
it is worth noting that linear gold complexes containing
substituted acetylide groups may easily incorporate,
through well established methods [5], ligands, such as
isonitriles, that can give to the resulting species liquid
crystalline properties. Less known for this purpose are
the gold compounds containing fluorinated aryl rings
[6], which interestingly, render more thermally stable
In the course of our studies on supramolecular chem-
istry, we focused on a series of linear ditopic acetylide-
based gold(I) compounds [1] because of their potential
to construct supramolecular polygons such as triangles,
squares and more complex structures by metal-directed
self-assembly reactions [2,3]. On the other hand, a num-
*
Corresponding author. Tel.: +34 93 403 91 31; fax: +34 93 490 77
25.
E-mail address: montse.ferrer@qi.ub.es (M. Ferrer).
0022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.02.043

M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 2200–2208
2201
compounds. Although the understanding of the struc-
ture–property relationships of the gold-containing liquid
crystals is reasonably good, much work still needs to be
done. To this end, we undertook the synthesis of a series
of new isonitrile gold complexes bearing acetylene or flu-
oroaryl ligands in order to study and compare the mes-
ogenic behaviour of both groups of complexes.
2. Results and discussion
2.1. Synthesis and characterization
The isonitrile gold(I) complexes were prepared fol-
lowing different synthetic methods. [AuCl(CNC6H4-
O(O)CC6H4OC10H21)] (1) was obtained by reacting
[AuCl(tht)] with the isonitrile CNC6H4O(O)CC6H4O-
C10H21-p in a CH2Cl2 solution at room temperature.
Compounds 2b, 3b and 4b were synthesized in good
yields using the reactions outlined in Scheme 1, follow-
ing a well-known strategy [5]. Firstly, the free acetylenes
were reacted with [AuCl(tht)] (tht = tetrahydrothioph-
ene) in the presence of NaOAc as base to give the insol-
uble [Au(C„CR0)]n derivatives (2a, 3a and 4a). In the
next step, a suspension of the latter compounds in tolu-
ene was treated with the isonitrile CNC6H4O(O)C-
C6H4OC10H21-p at room temperature to yield the
soluble complexes 2b, 3b and 4b.
Compound 5 was obtained by reacting [PPh4][Au
(C„CC5H4N)2] with C10H21I in a 1:10 molar ratio in
CH2Cl2 at 40 ꢁC for four days (Eq. (1)). The product
was precipitated from the solution as grey solid in rea-
sonably good yields. The formation of 5 can be rational-
ized on the basis of a ligand redistribution process of the
intermediate [Au(C„CC5H4N)(C„CC5H4NC10H21)].
Scheme 1.
compounds in which the triple bond is coordinated to
gold.
All the other complexes have been characterized by
C, H, N analyses, IR and NMR spectroscopy and mass
spectrometry. In addition, the molecular structure of 2b
has been solved by X-ray diffraction analysis. The IR
spectra of 2b–4b show one band for the C„CAu stretch,
slightly shifted to higher energy (ca. 5 cmꢀ1) in relation
to the starting polymers. In addition, 4b displays an-
other C„C absorption at 2214 cmꢀ1 due to the alkynyl
unit unbonded to the metal. The isonitrile derivatives
present one C„N band that appears in the 2215–
2225 cmꢀ1 region at about 100 cmꢀ1 higher wavenum-
bers than for the free isonitrile. The increase in the
ð1Þ
6b–8b were synthesized by displacement of tetrahydrot-
iophene from [AuR(tht)] (R = C5F4N, C6F4C5H4N and
C6F5) by the isonitrile: (Scheme 2).
The three [Au(C„CR0)]n (2a–4a) are pale yellow
solids that are insoluble in common non-coordinating
solvents. Elemental analyses support the stoichiometry.
The IR spectra show only one C„C absorption in
the range 2116–2126 cmꢀ1, as expected for polymeric
CN stretching frequency of coordinated isocyanide is
attributed to the r donation of the antibonding carbon
lone pair to gold upon complexation [7]. FAB(+) mass
spectra of 1, 2b–4b and 6b–8b contain the molecular
peaks, corresponding in most of the cases to [M+H+]
(Section 3).
1
The H NMR spectra of compounds 1, 2b–4b, 6b–8b
show four distorted doublets in the range 8.12–6.99 ppm

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M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 2200–2208
+
R-Br
BuLi
F
F
ether or THF
N
6a, 6b
7a, 7b
R =
R =
F
F
F
F
R-Li
N
[AuCl(tht)]
F
F
F
F
[AuR(tht)]
R =
8a, 8b
F
6a, 7a, 8a
F
F
O
C
CN
O
O
C10H21
O
C
R
Au
CN
O
O
C10H21
6b, 7b, 8b
Scheme 2.
with apparent coupling constants of 8.7–8.9 Hz that cor-
respond to the aromatic hydrogens of the isonitrile
rings. In addition, the first methylene group of the alk-
oxy chain of the isonitrile group is observed as a triplet
centred at 4.05 ppm in all cases and the remaining chain
hydrogens appear in the range 1.85–0.85 ppm.
(Fmeta). Compound 8b presents three different types of
fluorine atoms whose chemical shifts are: ꢀ118.5,
ꢀ159.9 and ꢀ164.9 ppm and were assigned to Fortho
,
Fpara and Fmeta, respectively.
2.2. Crystal structure of 2b
The hydrogens of the pyridine groups give rise to pairs
of doublets (AA0XX0 spin system) at 8.48 (Ha-py) and
Crystals for X-ray analysis were grown by ether va-
pour diffusion in a CH2Cl2 solution of 2b. Unfortu-
nately, after numerous trials only bad quality crystals
could be obtained, but the interest of the structural dis-
position of the molecules encouraged us to perform the
study. The structure of 2b is shown in Fig. 1, together
with the atomic numbering scheme; the most significant
bond distances and angles are listed in Table 1.
7.31 ppm (Hb-py) (2b), 8.59 (Ha-py) and 7.53 ppm (Hb-py
)
for compound 4b and 8.71 ppm (Ha-py) and 7.40 ppm
(Hb-py) for 7b. Apparent coupling constants are 6.0, 4.4
and 5.5 Hz, respectively. Compounds 3b and 4b show a
singlet (3b) or a multiplet (4b) for the four hydrogens
of the aromatic rings linked to the triple bond.
1
The H NMR spectrum of compound 5 shows four
multiplets between 8.77 and 7.11 ppm, with the protons
of the pyridine group linked to the alkyl chain (8.77 and
7.80 ppm) downfield in comparison with the respective
pyridine protons of the anion (8.35 and 7.11 ppm). Al-
kyl chain hydrogens show a pattern similar to that ob-
served in compounds 1, 2b–4b, 6b–8b.
The 19F NMR of compounds 6b and 7b are very sim-
ilar. In both cases, there are two types of signals corre-
sponding to the two different types of fluorine atoms.
For 6b, the signals correspond to an AA0XX0 spin sys-
tem and appear at ꢀ98.5 and ꢀ124.0 ppm, and they
are assigned to Fortho and Fmeta to gold, respectively.
For 7b, the signals correspond to a more complex spin
system, because the Fmeta to gold present an additional
coupling with the aromatic hydrogens of the pyridine
ring, and appear at ꢀ118.9 (Fortho) and ꢀ147.1 ppm
The molecule has, as expected, an extended close lin-
ear structure where the C(7)AuC(8), C(7)C(6)C(3) and
C(8)N(2)C(9) angles show a slight deviation from the
ideal angle of 180ꢁ. In the crystal (Fig. 2), the molecules
are packed as a bimolecular assembly with an antiparal-
lel alignment of the two monomers. A close analysis re-
veals that no direct gold–gold interaction exists, in
contrast with some reports in the literature [8]. Thus,
the shortest intermolecular gold–gold distance is
˚
6.835 A, which is out of the range for considering a
˚
bonding interaction (ca. 2.75–3.40 A).
If the standard deviations are taken into account, the
structural parameters of 2b are in the range found for
other similar compounds [1,9], but unfortunately the
poor quality of the resolution precludes a detailed
comparison.

M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 2200–2208
2203
Fig. 1. ORTEP drawing of the molecular structure and numbering scheme of compound 2b.
Table 1
giving focal-conic texture at temperatures close to the
clearing point (Fig. 3), and a fan-shaped texture on cool-
ing from the isotropic phase (Fig. 4) [11–13]. Compound
1 shows, in addition to SmA, a second mesophase at
lower temperatures. This mesophase displays a broken
fan-shaped texture formed on cooling the fan-shaped
area of the SmA phase, and regions with a schlieren mo-
saic texture formed on cooling the homeotropic regions
of the SmA phase (Fig. 5). These observations are con-
sistent with a smectic F mesophase [11–13]. In contrast,
complex 4b melts directly to an isotropic liquid with
extensive decomposition, and the ionic derivative 5
decomposes at 219 ꢁC without melting, thus they are
not liquid crystals. For this reason, the data for both
compounds 4b and 5 are referred to the first DSC cycle.
Some of the complexes show crystal–crystal transi-
tions before the melting temperature, and most of them
undergo significant decomposition at the clearing tem-
perature possibly due to the high transition tempera-
tures. In addition, it is important to note that the
alkynyl derivatives show the lowest thermal stability of
the complexes described in this work. Most likely this
behaviour is due to the high thermal lability of Au–alky-
nyl bond. However, it is remarkable that our alkynyl
˚
Selected interatomic distances (A) and bond angles (ꢁ) of 2b
C(6)–C(7)
C(7)–Au(1)
1.26(4)
1.97(3)
1.17(3)
1.99(3)
177(3)
170(2)
175(2)
173(2)
172.8(9)
C(8)–N(2)
C(8)–Au(1)
C(7)–C(6)–C(3)
C(6)–C(7)–Au(1)
N(2)–C(8)–Au(1)
C(8)–N(2)–C(9)
C(7)–Au(1)C(8)
2.3. Mesogenic behaviour
The thermal behaviour of the complexes 1, 2b–4b, 5
and 6b–8b (seven neutral complexes and an ionic deriv-
ative) was studied; six of them are liquid crystals. Their
optical, thermal and thermodynamic data are collected
in Table 2.
The free isonitrile displays smectic A and nematic
mesophases in the range 68–84 ꢁC [10]. Complexes 1,
2b, 3b, 6b, 7b and 8b derivatives display a SmA meso-
phase, which has been identified in optical microscopy
by their typical oily streaks and homeotropic textures
Fig. 2. View of the unit cell of 2b, normal to the (100) plane.

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M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 2200–2208
Table 2
Optical, thermal and thermodynamic data of complexes
[AuR(CNC6H4O(O)CC6H4OC10H21)] and [Au(C„CC5H4NC10H21)2]-
[Au(C„CC5H4N)2]
Compound Transitiona
Temperatureb (ꢁC) DHb (KJ/mol)
1
C–SmF
132.2
152.3
270c
18.3
2.1
SmF–SmA
SmA–I (dec)
C–C0
2b
3b
113.2d
144.2d
180.0c,d
55.9d
1.9
25.2
C0–SmA
e
SmA–I (dec)
CX–CY
CY–SmA + CW
CW + SmA–CW 120.5d
2.2f
103.2d
24.4
ꢀ6.5
19.9
ꢀ14.5
ꢀ3.9f
4.0f
CW–SmA
SmA–CW
149.5d
131.7
59.0
CW–CZ
CZ–SmA + CM
58.0
SmA + CM–CW 105.5
Fig. 4. Polarized optical microscopic fan-shaped texture (100·)
observed for 6b obtained on cooling from the isotropic liquid at 95 ꢁC.
ꢀ3.3
18.6
C
W–SmA
146.9
178.0c
175.0c,d
219.0c,d
94.7
SmA–I (dec)
C–I (dec)
C–dec
e
e
4b
5
6b
C–SmA
SmA–I
C–C0
49.7
1.4
101.2
73.9
87.4
215.0c
88.8
7b
8b
a
0.7
18.7f
C0–SmA
SmA–I (dec)
C–C0
e
1.8
C0–SmA
126.9
167.5
24.6
3.0
SmA–I
C, crystal; CX, CY, CZ, CW, CM, uncharacterized crystalline phases;
Sm, smectic; I, isotropic liquid.
b
Data referred to the second DSC cycle starting from the crystal.
Temperature data as peak onset.
c
Microscopic data.
Data referred to the first DSC cycle starting from the crystal
d
obtained by cooling the SmA mesophase.
e
Decomposition precludes measurement.
Combined enthalpies. dec, decomposition.
f
Fig. 5. Polarized optical microscopic texture (100·) for 1 at 160 ꢁC.
The picture shows the broken fan-shaped texture of the SmF phase
formed on cooling from the fan-shaped focal-conic area of the SmA
phase, and a region with schlieren mosaic texture of the SmF phase
formed on cooling the homeotropic region of the SmA phase.
gold isocyanide complexes show a slightly higher ther-
mal stability than that of analogous mesomorphic gold
alkynyl isocyanide complexes reported, which decom-
pose at ca. 160 ꢁC [4b,10].
The mesogenic derivative 3b appears in several solid
polymorphic forms with different melting points, and
exhibits the so-called double melting behaviour via the
SmA mesophase (Fig. 6) [14].
The variation in the melting temperatures of gold(I)
complexes studied is quite regular, decreasing in the or-
der: 5 > 4b > 3b > 2b > 1 > 8b > 6b > 7b.
Metal-containing liquid crystals can present intermo-
lecular metal–metal interactions, and it has been sug-
gested that such interactions are very important for
the formation and stabilization of mesophases in these
systems [10,15]. However, X-ray analysis has revealed
Fig. 3. Polarized optical microscopic textures (100·) observed for 2b
obtained on heating from the solid at 155 ꢁC. The picture shows oily
streaks and homeotropic zones.

M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 2200–2208
2205
observed. Similarly, the polarizability of the
C6H4C„CC5H4N group is clearly higher than that of
C5H4N and C6H4CN groups, and as a consequence
the melting temperatures should vary in the order
4b > 3b > 2b, as experimentally found.
Comparing now the thermal properties of the chloro
compound (1) with those of perfluoroaryl derivatives
(6b, 7b, 8b) (Table 2), it can be seen that the perhalophe-
nyl groups produce lower transition temperatures,
shorter mesogenic ranges, and an enhancement of
SmA phases, according to the expected lower lateral
intermolecular interactions as a consequence of their
greater molecular width. In keeping with the variation
of the polarizabilities and the previous discussion, the
melting temperatures should decrease in the order
7b > 8b > 6b; however, the variation experimentally
found is 8b > 6b > 7b. It is known that in 4-perfluor-
ophenylpyridines the perfluorophenyl ring is signifi-
cantly twisted with respect to the plane of the pyridine
ring [17,18]. This non-planar structure must necessarily
reduce the intermolecular interactions leading to lower
melting temperatures.
Fig. 6. DSC scans of 3b. (a) First heating, (b) first cooling, (c) second
heating.
Compound 5 is very different from the rest, because its
structure contains two alkyl chains and in addition it is
an ionic species. An increase of the number of the alkyl
chains can cause an increase in the degree of disorder
associated with the chains, producing lower transition
temperatures. However, the molecular arrangement of
an ionic complex made up of anisotropic organometallic
ions is due to both electrostatic and van der Waals inter-
actions between the fragments that constitute the com-
plex [19]. These factors produce an increase in the
intermolecular interactions leading to higher transition
temperatures. Thus, it is not surprising that the ionic
compound 5 shows the highest melting temperature.
that no gold–gold interactions are present in 2b. Thus, it
is obvious that the rather strong intermolecular interac-
tions operating in 2b are not due to metal–metal interac-
tions. The same result was found for other mesogenic
alkynylgold complexes [10].
In order to understand the thermal behaviour of the
compounds studied here, they can be considered as for-
mal derivatives of 1 by replacing the Cl ligand for an
alkynyl group (compounds 2b, 3b, 4b) or a perfluoroaryl
ligand (derivatives 6b, 7b, 8b). The introduction of alky-
nyl groups leads to higher values for the molecular
polarizability as an alkynyl group is more polarizable
than Cl, increasing intermolecular interactions and lead-
ing to higher melting temperatures [16]. In addition, the
variation in the size of the molecule on going from Cl to
alkynyl groups produces an increase in the total length
of the molecule, whereas the molecular breadth (consid-
ered as a cylinder) increases slightly, since the latter is
essentially determined by the bulkier benzoatephenyliso-
cyanide ligand. Thus, the intermolecular interactions in
the alkynyl derivatives should be stronger than in the
chloro complex, leading to higher transition tempera-
tures, as observed.
Analogously, 3b and 4b can be considered as formal
derivatives of 2b by replacing the pyridine group with
a C6H4CN moiety (3b) and with a C6H4C„CC5H4N
group (4b). The introduction of a C6H4CN substituent
leads to higher values for the molecular polarizability
as C6H4CN is more polarizable than the pyridine group
[16], increasing intermolecular interactions and leading
to higher transition temperatures. Thus, the melting
temperature of 3b should be higher than that of 2b, as
3. Experimental
3.1. General
All manipulations were performed under prepurified
N2 using standard Schlenk techniques. All solvents were
distilled from appropriate drying agents. Infrared spec-
tra were recorded on an FT-IR 520 Nicolet spectropho-
tometer. 1H NMR (d(TMS) = 0.0 ppm) spectra were
obtained on a Bruker DXR 250, Varian Gemini 200,
Varian Unity 300 and Varian Mercury 400 spectrome-
ters. 19F NMR (d(CFCl3) = 0.0 ppm) spectra were ob-
tained on a Varian Unity 300 and Varian Mercury 400
spectrometers. Elemental analyses of C, H and N were
`
carried out at the Institut de Bio-Organica in Barcelona.
FAB mass spectra were recorded on a Fisons VG Quat-
tro spectrometer. Microscopy studies were carried out
using a Leitz microscope provided with a hot stage
and polarizers at a heating rate of approx. 10 ꢁC minꢀ1
.

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M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 2200–2208
For differential scanning calorimetry (DSC) a Perkin–
Elmer DSC7 instrument was used, which was calibrated
with water and indium; the scanning rate was
10 ꢁC minꢀ1, the samples were sealed in aluminium cap-
sules in the air, and the holder atmosphere was dry
nitrogen. Literature methods were used to prepare
[CNC6H4O(O)CC6H4OC10H21-p] [10], [AuCl(tht)] [20],
4-ethynylpyridyne [21], 4-ethynylbenzonitrile [22], (4-
ethynylphenyl)(4-pyridyl)acetylene [23], 4-(4-bromotet-
rafluorophenyl)pyridine [18], [Au(C6F5)(tht)] (8a) [20]
and [PPh4][Au(C„CC5H4N)2] [1].
45.13; H, 2.02; N, 3.51. Found: C, 45.05; H, 2.03; N,
3.49%.
3.2.4. Synthesis of [Au(C„CC5H4N)(CNC6H4O(O)-
CC6H4OC10H21)] (2b)
Solid
CNC6H4O(O)CC6H4OC10H21
(51 mg,
0.13 mmol) was added to a toluene (7 ml) suspension
of [Au(C„CC5H4N)]n (40 mg, 0.13 mmol). After
15 min of stirring, the resulting suspension was concen-
trated to dryness under vacuum and washed with hexane.
The solid residue was dissolved in dichloromethane
(2 ml) and the addition of diethylether caused the precip-
itation of compound 2b as a white solid. Yield: 60%. IR
(KBr, cmꢀ1), 2920 s, 2851 m, m(C–H); 2221 m, m(C„N);
3.2. Synthesis and characterization data
1
3.2.1. Synthesis of [AuCl(CNC6H4O(O)-
CC6H4OC10H21)] (1)
2130 w, m(C„C); 1729 s, m(C„O). H NMR (298 K,
CDCl3): 8.48 (d, J(H–H) = 6.0 Hz, 2H, Ha-py), 8.11 (d,
J(H–H) = 8.9 Hz, 2H, (O)C–C6H4–O), 7.61 (d, J(H–
H) = 9.0 Hz, 2H, CN–C6H4–O), 7.38 (d, J(H–H) =
8.9 Hz, 2H, (O)C–C6H4–O), 7.31 (d, J(H–H) = 6.0 Hz,
2H, Hb-py), 6.98 (d, J(H–H) = 9.0 Hz, 2H, CN–C6H4–
O), 4.05 (t, J(H–H) = 6.6 Hz, 2H, CH2–O–C6H4), 1.85–
1.22 (m, 16H, C8H16), 0.88 (t, J(H–H) = 5.8 Hz, 3H,
CH3). FAB(+) m/z: 679.3 (M + H+, calc.: 679.0). Anal.
Calc. for C31H33AuN2O3: C, 54.87; H, 4.90; N, 4.13.
Found: C, 54.85; H, 4.89; N, 4.16%.
Solid
CNC6H4O(O)CC6H4OC10H21
(120 mg,
0.32 mmol) was added to a dichloromethane (15 ml)
solution of [AuCl(tht)] (100 mg, 0.32 mmol). After
15 min of stirring a white solid was obtained. The addi-
tion of hexane favours the precipitation of compound 1.
During all the manipulations, the solution was protected
from the light in order to avoid decomposition. Yield:
90%. IR (KBr, cmꢀ1), 2919 s, 2851 s, m(C–H); 2235 s,
1
m(C„N); 1724 s, m(C„O). H NMR (298 K, CDCl3):
8.10 (d, J(H–H) = 9.0 Hz, 2H, (O)C–C6H4–O), 7.60 (d,
J(H–H) = 9.1 Hz, 2H, CN–C6H4–O), 7.38 (d,
J(H–H) = 9.1 Hz, 2H, CN–C6H4–O), 6.97 (d, J(H–
H) = 9.0 Hz, 2H, (O)C–C6H4–O), 4.05 (t, 2H, J(H–
H) = 6.6 Hz, 2H, CH2–O–C6H4), 1.84–1.27 (m, 16H,
C8H16), 0.89 (t, J(H–H) = 6.3 Hz, 3H, CH3). FAB(+)
m/z: 1187.4 (2M ꢀ Cl, calc.: 1187.4), 1030.6
(2M ꢀ Cl ꢀ OC10H21, calc.: 1030.4). Anal. Calc. for
C24H29AuClNO3: C, 47.11; H, 4.78; N, 2.29. Found:
C, 47.15; H, 4.78; N, 2.34%.
3.2.5. Syntheses of [Au(C„CC6H4CN)(CNC6H4O(O)-
CC6H4OC10H21)] (3b) and [Au(C„CC6H4C„CA
C5H4N)(CNC6H4O(O)CC6H4OC10H21)] (4b)
Details of the synthesis of 2b also applied to 3b and
4b.
3b: Yield: 65%. IR (KBr, cmꢀ1): 2920 s, 2853 m, m(C–
H), 2219 s, br, m(C„NAC6H4O(O)C) + m(N„CAC6-
H4AC„C), 2122 w, m(C„C); 1737 s, m(C„O). 1H
NMR (298 K, CDCl3): 8.11 (d, J(H–H) = 8.9 Hz, 2H,
CO–C6H4–O), 7.61 (d, J(H–H) = 8.0 Hz, 2H, CN–
C6H4–O), 7.52 (s, 4H, C„CC6H4CN), 7.38 (d, J(H–
H) = 8.0 Hz, 2H, CN–C6H4–O), 6.98 (d, J(H–H) =
8.9 Hz, 2H, (O)C–C6H4–O), 4.05 (t, 2H, J(H–H) =
6.5 Hz, 2H, CH2–O–C6H4), 1.85–1.28 (m, 16H,
C8H16), 0.89 (t, J(H–H) = 6.3 Hz, 3H, CH3). FAB(+)
m/z: 703.3 (M + H+, calc.: 703.0). Anal. Calc. for
C33H33AuN2O3: C, 56.41; H, 4.73; N, 3.99. Found: C,
56.39; H, 4.72; N, 3.97%.
4b: Yield: 30%. IR (KBr, cmꢀ1): 2921 s, 2850 m, m(C–
H), 2220 w, br, m(C„N) + m(pyC„C), 2124 w,
m(C„CAu), 1735 s, m(C„O). 1H NMR (298 K, CDCl3):
8.59 (d, J(H–H) = 4.4 Hz, 2H, Ha-py), 8.11 (d, J(H–
H) = 8.1 Hz, 2H, (O)C–C6H4–O), 7.61 (d, J(H–H) =
7.7 Hz, 2H, CN–C6H4–O), 7.57–7.53 (m, 4H,
C„CC6H4C„C), 7.48 (d, J(H–H) = 7.7 Hz, 2H, CN–
C6H4–O), 7.37 (m, 2H, Hb-py), 6.98 (d, J(H–H) =
8.1 Hz, 2H, (O)C–C6H4–O), 4.05 (t, 2H, J(H–H) =
6.3 Hz, 2H, CH2–O–C6H4), 1.85–1.28 (m, 16H,
C8H16), 0.88 (t, J(H–H) = 6.0 Hz, 3H, CH3). FAB(+)
m/z: 779.3 (M + H+, calc.: 779.0). Anal. Calc. for
3.2.2. Synthesis of [Au(C„CC5H4N)]n (2a)
Solids [AuCl(tht)] (155 mg, 0.49 mmol) and NaOAc
(199 mg, 2.45 mmol) were added to a thf/MeOH 1:1
(14 ml) solution of 4-ethynylpyridine (50 mg,
0.49 mmol) at room temperature. After 30 min of stir-
ring, a pale yellow solid was obtained, which was
washed with methanol and thf. During all the manipula-
tions, the solution was protected from the light in order
to avoid gold deposition. Yield: 71%. IR (KBr, cmꢀ1),
2126 s, m(C„C). Anal. Calc. for C7H4AuN: C, 28.11;
H, 1.35; N, 4.68. Found: C, 28.14; H, 1.32; N, 4.70%.
3.2.3. Syntheses of [Au(C„CC6H4CN)]n (3a) and
[Au(C„CC6H4C„CC5H4N)]n (4a)
Details of synthesis of 2a also applied to 3a and 4a.
3a: Yield: 65%. IR (KBr, cmꢀ1): 2228 m, m(C„N),
2116 w, m(C„C). Anal. Calc. for C9H4AuN: C, 33.46;
H, 1.25; N, 4.34. Found: C, 33.47; H, 1.28; N, 4.35%.
4a: Yield 60%. IR (KBr, cmꢀ1): 2214 m, m(pyC„C);
2122 w, m(C„CAu). Anal. Calc. for C15H8AuN: C,

M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 2200–2208
2207
C39H37AuN2O3: C, 60.16; H, 4.79; N, 3.60. Found: C,
60.12; H, 4.77; N, 3.61%.
8.12 (d, J(H–H) = 8.9 Hz, 2H, (O)C–C6H4–O), 7.65 (d,
J(H–H) = 8.8 Hz, 2H, CN–C6H4–O), 7.42 (d, J(H–
H) = 8.9 Hz, 2H, (O)C–C6H4–O), 6.99 (d, J(H–H) =
9.0 Hz, 2H, CN–C6H4–O), 4.05 (t, J(H–H) = 6.7 Hz,
2H, –CH2–O–C6H4), 1.83–1.28 (m, 16H, C8H16), 0.88
(t, J(H–H) = 6.8 Hz, 3H, CH3). 19F NMR (298 K,
CDCl3, coaxial tube of CF3COOH in D2O): ꢀ98.5
(m, 2F, Fo), ꢀ124.0 (m, 2F, Fm). FAB (+) m/z:
727.0 (M + H+, calc.: 727.5). Anal. Calc. for
C29H29AuF4N2O3: C, 47.95; H, 4.02; N, 3.86. Found:
C, 47.23; H, 4.04; N, 3.83%.
3.2.6. Synthesis of [Au(C„CC5H4NC10H21)2]-
[Au(CCC5H4N)2] (5)
C10H21I (0.3 ml, 1.40 mmol) was added dropwise to a
dichloromethane (25 ml) solution of [PPh4][Au(C„C-
C5H4N)2] (100 mg, 0.14 mmol). After the resulting mix-
ture was heated for four days at 40 ꢁC, a grey solid was
obtained in 40% yield. IR (KBr, cmꢀ1), 2922 s, 2853 m,
m(C–H); 2109 s, m(C„Cpy), 2088 m m(C„CpyC10H21).
1H NMR (298 K, dmso-d6): 8.77 (m, 2H, Ha-py(cation)),
8.35 (m, 2H, Ha-py(anion)), 7.80 (m, 2H, Hb-py(cation)),
7.11 (m, 2H, Hb-py(anion)), 4.37 (m, 2H, CH2–C9H19),
1.82–1.21 (m, 16H, C8H16), 0.82 (t, J(H–H) = 6.1 Hz,
3H, CH3). FAB(+) m/z: 683.3 (M+, calc.: 683.0), 543.2
(M+ ꢀ C10H21 + H+, calc.: 543.0), 440.2 (M+ ꢀ C„
CpyC10H21, calc.: 440.0). FAB(ꢀ) m/z: 401.4 (Mꢀ, calc.:
401.0). Anal. Calc. for C48H58Au2N4: C, 53.14; H, 5.39;
N, 5.16. Found: C, 53.20; H, 5.39; N, 5.21%.
3.2.10. Syntheses of [Au(C6F4C5H4N)(CNC6H4O(O)-
CC6H4OC10H21)] (7b) and [Au(C6F5)(CNC6H4O(O)-
CC6H4OC10H21)] (8b)
Details of the synthesis of 6b also applied to 7b and
8b.
7b: Yield: 40%. IR (KBr, cmꢀ1): 2216 s, m(C„N),
1730 s, m(C„O), 1448 m, 947 m, 824, (C6F4). 1H
NMR (298 K, CDCl3): 8.71 (d, J(H–H) = 5.5 Hz, 2H,
Ha-py) 8.12 (m, 2H, (O)C–C6H4–O), 7.63 (m, 2H, CN–
C6H4–O), 7.41 (m, 2H, (O)C–C6H4–O), 7.40 (d, J(H–
H) = 5.5, 2H, Hb-py), 6.99 (m, 2H, CN–C6H4–O), 4.05
(t, J(H–H) = 6.5 Hz, –CH2–O–C6H4), 1.83–1.27 (m,
16H, C8H16), 0.88 (t, J(H–H) = 6.6 Hz, 2H, CH3). 19F
NMR (298 K, CDCl3, coaxial tube of CF3COOH in
D2O): ꢀ118.9 (m, 2F, Fo), ꢀ147.1 (m, 2F, Fm). FAB
(+) m/z: 803.0 (M + H+, calc.: 803.6). Anal. Calc. for
C35H33AuF4N2O3: C, 52.38; H, 4.14; N, 3.49. Found:
C, 52.22; H, 4.11; N, 3.51%.
8b: Yield: 69%. IR (KBr, cmꢀ1): 2217 s, m(C„N),
1724 s, m(C„O), 1510 s, 1067 br, 956 s, 802 m,(C6F5).
1H NMR (298 K, CDCl3): 8.12 (d, J(H–H) = 8.7 Hz,
2H, (O)C–C6H4–O), 7.63 (d, J(H–H) = 8.8 Hz, 2H,
CN–C6H4–O), 7.41 (d, J(H–H) = 8.7 Hz, 2H, (O)C–
C6H4–O), 6.99 (d, J(H–H) = 8.8 Hz, 2H, CN–C6H4–
O), 4.05 (t, J(H–H) = 6.5 Hz, –CH2–O–C6H4), 1.83–
1.28 (m, 16H, C8H16), 0.89 (t, J(H–H) = 6.6 Hz, 3H,
CH3). 19F NMR (298 K, CDCl3, coaxial tube of
CF3COOH in D2O): ꢀ118.5 (m, 2F, Fo), ꢀ159.9 (t,
3JF–F = 20 Hz, 1F, Fp), ꢀ164.9 (m, 2F, Fm). FAB (+)
m/z: 744.0 (M + H+, calc.: 744.5). Anal. Calc. for
C30H29AuF5NO3: C, 48,46; H, 3,93; N, 1,88. Found:
C, 48.30; H, 4.01; N, 1.81%.
3.2.7. Synthesis of [Au(C5F4N)(tht)] (6a)
n-BuLi (1.6 M in hexane) (3 ml, 0.31 mmol) was
slowly added to a stirred diethyl ether solution (20 ml)
of 4-bromotetrafluoropyridine (0.037 ml, 0.31 mmol) at
ꢀ78 ꢁC. After 1 h, the flask was shielded from light with
aluminium foil, 100 mg (0.31 mmol) of [AuCl(tht)] were
added and the mixture was stirred under a nitrogen
atmosphere for 1 h while the temperature was main-
tained at ꢀ78 ꢁC. After the mixture was allowed to
warm to 15 ꢁC, the precipitated LiCl was filtered off.
The filtered solution was evaporated to 5 ml and
the addition of hexane caused the precipitation of com-
pound 6a. Yield: 37%. IR (KBr, cmꢀ1): 1625 m, 1446 s,
1203 m, 921 m, (C5F4N). Anal. Calc. for C9H8AuF4NS:
C, 24.84; H, 1.85; N, 3.22; S, 7.37. Found: C, 24.73; H,
1.83; N, 3.18; S, 7.41%.
3.2.8. Synthesis of [Au(C6F4C5H4N)(tht)] (7a)
Details of the synthesis of 6a also applied to 7a. Yield:
40%. IR (KBr, cmꢀ1): 1443 m, 946 m, (C6F4). Anal. Calc.
for C15H12AuF4NS: C, 35.24; H, 2.36; N, 2.74; S, 6.27.
Found: C, 35.90; H, 2.38; N, 2.66; S, 6.55%.
3.2.9. Synthesis of [Au(C5F4N)(CNC6H4O(O)-
CC6H4OC10H21)] (6b)
Solid
CNC6H4O(O)CC6H4OC10H21
(26 mg,
4. Crystal structure determination of complex 2b
4.1. Crystal data
0.07 mmol) was added to a dichloromethane (10 ml)
solution of [Au(C5F4N)(tht)] (6a) (30 mg, 0.07 mmol).
After 45 min of stirring, the mixture was filtered to sep-
arate possible colloidal gold. The filtered solution was
evaporated to 5 ml under vacuum. Addition of hexane
(5 ml) caused the precipitation of a white solid which
was filtered off to give 6b. Yield: 40%. IR (KBr,
cmꢀ1): 2221 s, m(C„N), 1730 s m(C„O), 1629 m, 1448
C31H33AuN2O3, M = 678.56, triclinic, a = 6.574(5),
˚
b = 12.422 (7), c = 18.322(5) A, a = 74.97(5), b = 85.91
3
˚
ꢀ
(5), c = 76.11(4)ꢁ, U = 1402.7(14) A , space group P1
ꢀ1
˚
(no. 2), Z = 2, k = 0.71073 A, l(Mo Ka) = 5.277 mm
.
The intensity data sets were collected at 150(2) K on a
Bruker–Nonius KappaCCD diffractometer equipped
1
s, 1206 m, 923 s, (C5F4N). H NMR (298 K, CDCl3):

2208
M. Ferrer et al. / Journal of Organometallic Chemistry 690 (2005) 2200–2208
´
(c) S. Coco, P. Espinet, S. Falagan, J.M. Martın-Alvarez, New. J.
´
with an Oxford Cryostream 700 unit on a 0.60 ·
0.30 · 0.10 mm3 prismatic colourless crystal. Multi-scan
absorption correction was performed using the SORTAV
program [24]. Although 16065 reflections were measured
in a range from 3ꢁ to 27.5ꢁ in theta, the quality was quite
poor, and two filters had to be applied to the data set to
get a reasonable resolution, a limit of 20ꢁ in theta and I
> 2r(I). The filtered set contained 3183 measured reflec-
tions, 1912 unique (Rint = 0.147) (73.5% completeness),
which were used in all calculations. The structure was
solved using the WINGX package [25], by direct methods
(SHELXS-97) and refined by full-matrix least-squares
against F2 (SHELXL-97) [26] to give the final indices
R1 = 0.118 and wR2 = 0.294, ratio data/parameters
Chem. 19 (1995) 959;
(d) M. Benouazzane, S. Coco, P. Espinet, J.M. Martın-Alvarez,
´
J. Mater. Chem. (1995) 441.
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12 (1993) 4771.
´ ´
[6] (a) R. Bayon, S. Coco, P. Espinet, C. Fernandez-Mayordomo,
´
J.M. Martın-Alvarez, Inorg. Chem. 36 (1997) 2329;
´ ´
(b) S. Coco, C. Fernandez-Mayordomo, S. Falagan, P. Espinet,
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Payne, Organometallics 12 (1993) 263;
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Assmann, K. Angermaier, H. Schmidbaur, Inorg. Chem. 34
(1995) 75;
1912/155. Final residues of 3.211 and –3.132 e Aꢀ3 were
˚
˚
located at 1.16 and 1.25 A from Au1, respectively. Only
(c) G.A. Carriedo, V. Riera, X. Solans, J. Solans, Acta Crystal-
logr. Sect. C 44 (1988) 978.
the gold atom could be refined anisotropically and the
hydrogen atoms were placed in calculated positions, re-
fined using a riding model. Crystallographic data for the
structural analysis has been deposited with the Cam-
bridge Crystallographic Data Centre, CCDC No.
252120 for compound 2b. Copies of this information
may be obtained free of charge from: The Director,
CCDC, 12 Union Road, Cambridge, CB2 1EZ UK.
Fax. (int code) +44(1223)336 033 or Email: deposit@
ccdc.cam.ac.uk or www.ccdc.cam.ac.uk.
[10] T. Kaharu, R. Ishii, T. Adachi, T. Yoshida, S. Takahashi, J.
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VEB, Leipzig, 1980.
[12] G.W. Gray, J.W. Goodby, in: Smectic Liquid Crystals. Textures
and Structures, Hill, Glasgow, London, 1984.
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[16] R.R. Lide (Ed.), Handbook of Chemistry and Physics, 73rd ed.,
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Acknowledgements
[17] E.C. Constable, B. Karinki, A. Mahmood, Polyhedron 22 (2003)
687.
Financial support for this work was provided by the
DGICYT (Projects BQU2003-01131 and MAT2002-
00562) and the CIRIT (Project 2001SRG00054). M.M.
is indebted to the University of Barcelona for a
scholarship.
[18] M. Ferrer, M. Mounir, O. Rossell (in preparation).
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[20] R. Uson, A. Laguna, Organomet. Synth. 3 (1986) 324.
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