Replacement of the chloride ligand in [Au(C,N,N)Cl][PF6] cyclometallated complexes by C, N, O and S donor anionic ligands

Article abstract of DOI:10.1039/a903925b

Replacement of the chloride ligand in the cyclometallated complexes [Au(C,N,N)Cl][PF₆] (C,N,N = N₂C₁₀H₇(CH₂C₆H ₄)-6 1, N₂C₁₀H₇(CHMeC₆H

Full text of DOI:10.1039/a903925b

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Replacement of the chloride ligand in [Au(C,N,N)Cl][PF6]
cyclometallated complexes by C, N, O and S donor anionic ligands
Maria Agostina Cinellu,a Giovanni Minghetti,*a Maria Vittoria Pinna,a Sergio Stoccoro,a
Antonio Zuccaa and Mario Manasserob
a Dipartimento di Chimica, Università di Sassari, via Vienna 2, I-07100 Sassari, Italy.
E-mail: mingh@ssmain.uniss.it
b Dipartimento di Chimica Strutturale e Stereochimica Inorganica, Università di Milano,
Centro CNR, via Venezian 21, I-20133 Milano, Italy. E-mail: m.manassero@csmtbo.mi.cnr.it
Received 17th May 1999, Accepted 24th June 1999
Replacement of the chloride ligand in the cyclometallated complexes [Au(C,N,N)Cl][PF6]
(C,N,N = N2C10H7(CH2C6H4)-6 1, N2C10H7(CHMeC6H4)-6 2, or N2C10H7(CMe2C6H4)-6 3, where N2C10H8 = 2,2Ј-
bipy) by C, N, O and S donor anionic ligands Y was accomplished through different routes depending both on the
natureofHYortheC,N,Nligand.Stablealkoxo[Au(C,N,N)(OR)][PF6](R = MeorEt)andamido[Au(C,N,N)(NHAr)]-
[PF6] (Ar = C6H4NO2-4) complexes were obtained in fairly good yields. The molecular structure of the thiolato
complex [Au{N2C10H7(CMe2C6H4)-6}(SPh)][PF6] has been determined by X-ray crystallography. The diorgano-
gold() complex [Au(C,N,N)(C2Ph)][PF6] on addition of PPh3 (1:2) undergoes reductive elimination to give
[Au(PPh3)2][PF6] and an unsymmetric diarylacetylene.
Introduction
Results and discussion
Substitution reactions play an important role in organo-
transition metal chemistry being an essential first step, and
sometimes the rate-controlling step, in stoichiometric and
catalytic reactions.1
In a previous paper8 concerning the synthesis and the crystal
structures of a series of gold() cyclometallated complexes
[Au(C,N,N)Cl]ϩ 1–4 with 6-benzyl- and 6-alkyl-2,2Ј-bipyridines
we reported that displacement of the chloride by a neutral
ligand such as PPh3 occurs only in complex 4[BF4] to give
the dicationic derivative [Au(C,N,N)(PPh3)]2ϩ. Under the same
reaction conditions, complexes 2[BF4] and 3[BF4] undergo dis-
placement of the nitrogen trans to the carbon atom to yield
[Au(C,N-N)(PPh3)Cl]ϩ (C,N-N = C,N-ligated 6-benzyl-2,2Ј-
bipyridine). In the latter cases spectroscopic evidence suggested
that isomerization also occurs to give the more thermo-
dynamically stable complex, i.e. that with the C and P ligands in
mutually cis position.
Organogold chemistry has been recently reviewed2 in light
of the applications of some new derivatives in various fields
including homogeneous catalysis.3 Both gold-() and -()
organic derivatives are reported in the review and in more
recent papers: among them, gold() cyclometallated com-
plexes,4 a recent topic of interest, are described and their poten-
tial applications in organic synthesis,5 photochemistry4c,i,6 or
chemotherapy4e, f,7 pointed out as well. Replacement of halide
ions by suitable ligands is the general procedure to obtain most
of these cycloaurated complexes.
In a previous paper8 we have described the synthesis and the
crystal structures of a series of gold() cyclometallated com-
plexes [Au(C,N,N)Cl][X] (X = BF4 or PF6) with three 6-benzyl-
2,2Ј-bipyridines and one 6-alkyl-2,2Ј-bipyridine. Few other
gold() cyclometallated complexes with C,N,N tridentate
ligands, all bearing a chloride as fourth ligand, are reported6
and in no case substitution reaction derivatives.
In the present paper we describe the synthesis, characteriz-
ation and reactivity of a number of new gold() cyclo-
metallated derivatives [Au(C,N,N)(Y)][PF6] (C,N,N = 6-benzyl-
2,2Ј-bipyridine; Y = C-, N-, O- or S-donor anionic ligand)
obtained by replacement of a chloride ligand. Among these,
stable methoxo and ethoxo complexes [Au(C,N,N)(OR)][PF6]
are obtained in fairly good yields by means of different
approaches; these compounds are versatile intermediates in the
synthesis of other derivatives such as, for example the amido
complexes [Au(C,N,N)(NHAr)][PF6]. Gold alkoxides are an
attractive topic of interest in the light of the recent discovery of
the catalytic activity displayed by some gold-() and -() fluoro-
alkoxides.3a To the best of our knowledge simple alkoxo com-
plexes (R = Me or Et) are unprecedented in gold() chemistry,
whereas a few examples of amido species9 have been reported.
Further investigations will be devoted to ascertain the potential
of the new derivatives.
The forced displacement of the chloride from compound
2[BF4] by means of AgBF4 was also reported; the outcome of
the reaction, carried out in refluxing acetone, was an acetonyl
derivative [Au(C,N,N){CH2C(O)Me}][BF4], similar to those
described by Vicente et al.5c for C,N cycloaurated complexes
and reported to be efficient starting materials for the synthesis
of ketones via C–C coupling.
Successively we have observed that in the reaction of com-
pounds 2[BF4] and 3[BF4] with AgBF4 in acetone at room tem-
perature, besides acetonyl derivatives, dinuclear oxo-bridged
complexes [Au2(C,N,N)2(µ-O)][BF4]2 are formed.10 The latter
compounds are the first examples of gold() oxo-bridged
J. Chem. Soc., Dalton Trans., 1999, 2823–2831
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cyclometallated derivatives. The reactivity of these species is
currently under investigation.
equivalent likely owing to hindered rotation of the acac ligand
about the Au–C bond, as suggested by inspection of molecular
Surprisingly when complexes 1[PF6]–3[PF6] are treated with
AgPF6 in acetone solution the acetonyl derivatives [Au(C,N,N)-
{CH2C(O)Me}][PF6] 5–7 are solely obtained in high yields (ca.
80%). When silver or thallium salts of co-ordinating anions are
employed replacement of the chloride by the anionic ligands
occurs: [Au(C,N,N)(O2CMe)]ϩ 8 and 9 and [Au(C,N,N)(acac)]ϩ
10–12 [C,N,N = N2C10H7(CH2C6H4)-6 10, N2C10H7(CHMeC6-
H4)-6 8 and 11, N2C10H7(CMe2C6H4)-6 9 and 12; Hacac =
CH2{C(O)Me}2] are obtained in good yields from the reaction
at room temperature of complexes 1–3 with AgO2CMe in
acetone solution and with Tl(acac) in CH2Cl2, respectively
(Scheme 1).
models.
1
The H NMR spectrum of complex 10 in various solvents
features a more complicated situation; in CDCl3 singlets at
δ 16.36 and 16.30 (integral ratio 0.4:1) (which disappear by
addition of D2O) and two singlets at δ 5.31 and 5.29 (ca. 1:2)
(which do not exchange with D2O) are found for the two
tautomers, respectively. Besides these, several other minor
signals are present.
The C(3) bonding of the acetylacetonate anion in the keto
form to several metals including gold()12 is well established.
At variance such bonding in the enol form has been proposed
in some cases including gold().12a In our complexes, the
{Au(C,N,N)} fragment with formal charge ϩ2 can account
for the stabilization of the enol form: it is known that
electron-withdrawing substituents favour the enol tautomer of
β-diketones.13
In contrast to C,N cyclometallated gold() acetylacetonate
complexes, 10–12 do not activate acetone to give the corre-
sponding acetonyl derivatives.12b–e Treatment of 11 with acetone
for one day at room temperature results in a ca. ten per cent
increase of the enol tautomer (1H NMR criterion).
As it will be shown, the acetato derivatives 8 and 9 are useful
intermediates, therefore we tried to synthesize them by meta-
thesis reaction with sodium acetate. The reaction was carried
out in various solvents giving different results for the chloro
complexes 2 and 3. From the reaction of 2 in acetone a new
species [Au(C,N,N*)Cl]ϩ 2* was isolated which contains the
cyclometallated anion N2C10H7{C(OH)MeC6H4}-6, C,N,N*,
resulting from the activation of the benzylic C–H bond; no
displacement of the chloride was observed. Complex 3 reacts
only in part to give 9 and the acetonyl derivative. Unchanged 2
or 3 is recovered almost quantitatively when the reaction is
carried out in refluxing acetonitrile–water.
Scheme 1 (i) ϩAgPF6, Me2CO, ϪAgCl; (ii) ϩAgO2CMe, Me2CO,
ϪAgCl; (iii) ϩTl(acac), CH2Cl2, ϪTlCl, C,N,N = N2C10H7(CH2C6H4)-6
1, 5, 10; N2C10H7(CHMeC6H4)-6 2, 6, 8, 11; or N2C10H7(CMe2C6H4)-6
3, 7, 9, 12.
Activation of the solvent was also observed when complex 2
was treated with an equimolar amount of KOH in acetone or
in methanol. In acetone, a mixture of unchanged 2, acetonyl
derivative 6 and a unidentified product is obtained (1H NMR
criterion). Unchanged 2, dinuclear oxo [Au2(C,N,N)2(µ-O)]2ϩ
and methoxo [Au(C,N,N)(OMe)]ϩ 13 complexes were formed in
methanol; under these conditions no activation of the benzylic
C–H was observed. Unfortunately pure products cannot be
separated from these mixtures either by chromatography or
crystallization.
The reaction of complex 1 with AgO2CMe failed to give the
acetato derivative. The IR and H NMR spectra of a whitish
1
product, isolated in small amounts, are complex; the undoubted
fact is that activation of a benzylic C–H bond has occurred.
Complexes 8–12 gave satisfactory analyses and their molecular
ions Mϩ have been detected by FAB mass spectrometry (see
Experimental section).
Complexes 8 and 9 show strong bands at 1666 (νasym(CO2))
and 1270 cmϪ1 (νsym(CO2)) and 1669 and 1264 cmϪ1, respect-
ively, typical of monodentate O-bonded acetato ligands.11 The
IR spectra of the acetylacetonate derivatives 10–12 show one
medium absorption at 1675 cmϪ1, sometimes flanked by a
shoulder at ca. 1700 cmϪ1, i.e. in a region characteristic of the
Alkoxo complexes [Au(C,N,N)(OR)]ϩ (R = Me 15 or Et 16)
have been synthesized by metathesis reaction on 3 using sodium
alkoxide in the corresponding alcohol (Scheme 2). Under the
same conditions, 2 gave the methoxide [Au(C,N,N*)(OMe)]ϩ
13*; whereas with EtONa a mixture of unchanged 2, 2* and
C᎐O stretching modes of a C-bonded acac ligand.11 Neverthe-
᎐
less, the profile appears more complex than expected for such a
co-ordination mode, and other bands overlapped by those of
the bipyridine ligand in the region 1600–1575 cmϪ1 cannot be
1
excluded. The H NMR spectra in various solvents show the
presence of two isomers in molar ratios that depend on the
solvent. Complex 11 is a ca. 3:1 mixture of isomers: the major
species is characterized by the presence in the 1H NMR (CDCl3;
room temperature) of a sharp singlet at δ 16.30 (16.46 for 12)
which disappears upon addition of D2O (Table 1). We feel con-
fident to assign this resonance to a hydrogen-bonded OH of a
C-bonded acac ligand in the enol form. The second isomer
shows a resonance at δ 5.31 (5.30 for 12), which exchanges with
D2O, assigned to the α-methine proton of a C-bonded acac
ligand in the keto form. For complex 11 the molar ratio of the
two tautomers is slightly temperature dependent in the range
Ϫ80 to ϩ54 ЊC: on going from Ϫ80 to ϩ20 ЊC in CD2Cl2
solution a ca. seven per cent increase of the keto tautomer is
observed, whereas a comparable decrease is observed on going
from ϩ20 to ϩ54 ЊC in CDCl3 solution. In complex 11 the
methyl protons of the acac ligand in both tautomers are not
Scheme 2
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Table 1 Proton NMR dataa
Other
aromatics
Compound
Solvent
H6Ј
CH
CH2
Me
Others (Y)
1
2
(CD3)2CO
CD2Cl2
(CD3)2CO
CD2Cl2
(CD3)2CO
CDCl3
(CD3)2CO
CDCl3
9.42 (dd)
9.38 (dd)
9.45 (dd)
9.35 (dd)
9.40 (dd)
9.24 (dd)
9.41 (d)
9.25 (d)
8.78 (dd)
8.77 (dd)
8.69 (dd)
8.84 (dd)
d
8.83 (dd)
d
8.86 (dd)
9.10 (dd)
9.18 (dd)
9.19 (dd)
8.99–7.15
8.82–7.15
9.00–7.17
8.68–7.13
9.00–7.14
8.66–7.16
8.95–7.25
8.72–7.18
8.66–7.21
8.68–7.19
8.65–7.00c
4.93 (s)
4.79 (q, 7.2)
5.18 (q, 7.1)
1.85 (d, 7.2)
1.87 (d, 7.1)
2.14 (s)
3
2.19 (s)
5
6
4.53 (s)
3.50 (s) CH2; 2.33 (s) Me
3.62 (s) CH2; 2.29 (s) Me
3.50 (s) CH2; 2.31 (s) Me
2.35 (s) Me
4.99 (q, 7.3)
4.82 (q, 7.2)
1.89 (d, 7.3)
2.10 (s)
1.85 (d, 7.2)
2.14 (s)
7
8
CD2Cl2
CD2Cl2
CDCl3
9
2.35 (s) Me
10b
[1.5]
[1]
[2.6]
[1]
[1.3]
[1]
4.63 (s)
4.57 (s)
16.36 (s), 16.30 (s) OH; 2.25 (s) Me
5.31 (s), 5.29 (s) CH; 2.48 (s) Me
16.30 (s) OH; 2.30 (s), 2.22 (s) Me
5.31 (s) CH; 2.49 (s), 2.46 (s) Me
16.46 (s) OH; 2.25 (s) Me
5.30 (s) CH; 2.47 (s) Me
11b
12b
CDCl3
CDCl3
8.74–7.03c
8.76–7.08c
4.65c (q, 7.3)
1.81 (d, 7.3)
1.92 (d, 7.3)
2.11 (s)
2.15 (s)
2.04 (s)
1.80 (d, 7.1)
1.81 (d, 7.3)
13*
13
14
CD2Cl2
CD2Cl2
CD2Cl2
8.64–7.25
8.64–7.34
8.63–7.34
3.86 (s) MeO; 3.43 (s, br) OH
3.91 (s) MeO
4.79 (q, 7.1)
4.78 (q, 7.3)
4.05 (m, 2J = 10.5; 3J = 6.8) CH2;
1.50 (t, 6.8) Me
3.94 (s) MeO
15
16
17
18
19
CD2Cl2
CD2Cl2
CDCl3
CD2Cl2
(CD3)2CO
9.14 (dd)
9.15 (dd)
9.31 (d)
9.38 (dd)
9.17 (d)
8.63–7.31
8.62–7.27
8.74–7.08e
8.67–7.09e
8.99–7.09
2.11 (s)
2.10 (s)
1.74 (d, 7.1)
2.07 (s)
1.90 (d, 7.1)
4.06 (q, 6.8) CH2, 1.51 (t, 6.8) Me
4.61 (q, 7.1)
5.12 (q, 7.1)
7.95 (d, 9.0, 2H) Hmeta; 7.12 (d, 9.0, 2H)
Hortho; 6.90 (s) NH
20
(CD3)2CO
9.13 (dd)
9.00–7.05
2.21 (s)
7.94 (d, 9.3, 2H) Hmeta; 7.07 (d, 9.3, 2H)
Hortho; 6.92 (s) NH
21
22
CD2Cl2
CD2Cl2
9.54 (d)
9.46 (dd)
8.69–7.21f
8.67–7.15f
4.77 (q, 7.2)
1.84 (d, 7.2)
2.11 (s)
a Spectra recorded at room temperature; chemical shifts in ppm from internal SiMe4, coupling constants (in parentheses) in Hz. b Enol and keto
isomers, integral ratios are in square brackets; the first line refers to the enol unless otherwise stated. c Enol ϩ keto. d Overlapped. e C,N,N ϩ PhS.
f C,N,N ϩ PhC2.
trace amounts of the ethoxide [Au(C,N,N)(OEt)]ϩ 14 are
formed.
strong ν(C–O) absorptions at 1016 and 1024 cmϪ1 respectively;
the MeO protons resonate at δ 3.91 (complex 13) and 3.94 (15)
in CD2Cl2. For complex 14 the ethoxide protons appear as an
AAЈB3 pattern: the diastereotopic methylene protons give rise
Once again, treatment of complex 2 with strong bases
resulted in activation of the co-ordinated ligand. Since in the
presence of benzylic C–H bonds this approach for the
substitution of the chloride ligand is not straightforward a
different route for the preparation of alkoxides was developed,
at least for 2. In a typical reaction, the acetato derivative
[Au(C,N,N)(O2CMe)]ϩ 8 was dissolved in methanol and the
resulting solution stirred at room temperature until a white pre-
cipitate of the methoxide 13 was separated in fairly good yield.
The analogous reaction of 8 in ethanol to give the ethoxide 14
required a slightly modified procedure (see Experimental sec-
tion). σ-Ligand metathesis reaction is a very useful synthetic
method to prepare late transition metal alkoxides by addition
of alcohols to other metal alkoxides, amides or hydroxides;14
less common is the metathesis of an acetato complex. Com-
plexes 13–16 are the first isolated methoxo- and ethoxo-gold
complexes: actually, gold alkoxides are rare and unstable unless
bulky alkoxides, fluoro-substituted alkoxides or aryl oxides
are employed.15 Recently a series of gold-() and -() fluoro-
alkoxides displaying catalytic activity has been reported.3a
Complexes 13–16 are air stable white solids with relatively
high melting points; they gave satisfactory analyses and their
molecular ions Mϩ have been detected by FAB mass spec-
trometry. The IR spectra of 13 and 15 are characterized by
2
to two doublets of quartets at δ 4.05 (CD2Cl2) with J = 10.5
and 3J = 6.8 Hz; the methyl protons appear as a triplet at δ 1.50
with J = 6.8 Hz. At variance with 14, the methylene protons in
complex 16 are equivalent giving rise to a quartet at δ 4.06
(CD2Cl2) with 3J = 6.8 Hz; the methyl protons appear as a
triplet at δ 1.51.
The acetato complexes do not react with the more bulky and
less acidic t-BuOH under various reaction conditions. As
expected, the reaction with the more acidic PhSH proceeds
smoothly to yield the thiolato complexes [Au(C,N,N)(SPh)]ϩ
(C,N,N = N2C10H7(CHMeC6H4)-6 17, or N2C10H7(CMe2C6H4)-
6 18) (Scheme 3). They are air stable bright yellow solids soluble
in the common organic solvents. The crystal structure of
18[PF6] has been determined by single crystal X-ray diffraction
(see below). Complexes 17 and 18 are likewise easily obtained
from the reaction of the methoxides 13 and 15 with PhSH. The
methoxo complexes [Au(C,N,N)(OMe)]ϩ are intermediates
more versatile than the acetato derivatives being able to abstract
a proton from weak acids such as PhC2H or NH2C6H4NO2-4 to
give the σ-ligand metathesis products. The monomeric amido
complexes [Au(C,N,N)(NHAr)]ϩ (C,N,N = N2C10H7(CHMeC6-
H4)-6 19 or N2C10H7(CMe2C6H4)-6 20) are formed in high
J. Chem. Soc., Dalton Trans., 1999, 2823–2831
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Scheme 3 (i) ϩROH, ϪMeCO2H; (ii) ϩPhSH, ϪMeCO2H; (iii) ϩPhSH, ϪMeOH; (iv) ϩH2NC6H4NO2-4, ϪMeOH; (v) ϩPhC2H, ϪMeOH.
C,N,N = N2C10H7(CHMeC6H4)-6 13, 14, 17, 19, 21 or N2C10H7(CMe2C6H4)-6 15, 16, 18, 20, 22; R = Me 13, 15 or Et 14, 16.
yields by treatment of 13 and 15, respectively, with the amine in
dichloromethane solution. The reaction is most likely revers-
ible;14 it is driven to completion by the addition of an excess of
reagent as well as by the low solubility of the product in the
reaction solvent. The amido complexes 19 and 20 are orange-
yellow air stable compounds both in the solid state and in
solution at room temperature. The IR spectra are characterized
by a sharp strong ν(N–H) absorption at 3350 cmϪ1 and by very
strong absorptions at ca. 1580 and ca. 1280 cmϪ1 due to the
asymmetric and symmetric stretching vibrations of the NO2
1
group. The H NMR spectra in (CD3)2CO of 19 and 20 reveal
a medium broad singlet at δ 6.90 and 6.92, respectively, for
Scheme 4
the N–H proton which disappears upon addition of D2O. The
Au:PPh3 = 1:2), at room temperature, undergoes reductive
aromatic region shows, for both complexes, well separated
resonances for the fifteen protons. For 19 broadening of the H6Ј
and H3Љ resonances is observed at room temperature likely due
to coupling to the 14N quadrupole nucleus of the NHC6H4NO2-
4 ligand.
elimination to give [Au(PPh3)2][PF6] and the C–C coupling
product N2C10H7{CMe2C6H4(C2Ph)-2Љ}-6 23 in quantitative
yields (Scheme 4). Various C–C coupling products have been
obtained by thermolysis of alkyl-,16 alkylaryl-,16e,17 alkyl(alkoxy-
carbonyl)-18 and vinyl-gold()16e,19 complexes. Symmetrical and
unsymmetrical biaryls as well as benzyl alkyl and benzyl aryl
ketones have been synthesized under mild conditions via C–C
coupling by addition of PPh3 to cis-diaryl-5a,d and arylketonyl-
gold()5c complexes, respectively. As far as we know, 23 is the
first unsymmetrical diarylacetylene obtained via C–C coupling
from an organogold compound.
The methoxo complex [Au{N2C10H7(CMe2C6H4)-6}(OMe)]ϩ
15 undergoes facile exchange reaction with PhC2H to give the
alkynyl derivative [Au{N2C10H7(CMe2C6H4)-6}(C2Ph)]ϩ 22;
only small amounts of the analogous complex [Au{N2C10H7-
(CHMeC6H4)-6}(C2Ph)]ϩ 21 are obtained from 13. In the latter
case the outcome of the reaction is the oxo complex [Au2-
{N2C10H7(CHMeC6H4)-6}2(µ-O)]2ϩ. Similar results were found
even when the ethoxide 14 was employed in place of 13. In the
Structural data for [Au{N2C10H7(CMe2C6H4)-6}(SPh)][PF6]
18[PF6]
IR spectra of the alkynyl derivatives no absorption due to the
᎐
C᎐C stretching mode was observed, nevertheless a medium
᎐
intensity band at ca. 700 cmϪ1 indicates the presence of a mono-
The structure in the solid state of complex 18[PF6] has been
solved by X-ray diffraction. It consists of the packing of
1
substituted phenyl ring. In the H NMR spectra in CD2Cl2 of
21 and 22 the resonance of the H6Ј proton is strongly deshielded
due to anisotropy effects originated by the alkynyl ligand; the
aromatic protons are in the correct integral ratios.
[Au{N2C10H7(CMe2C6H4)-6}(SPh)]ϩ cations and PF6 anions
Ϫ
with normal van der Waals contacts. An ORTEP20 view of the
cation with the atom labelling scheme is shown in Fig. 1.
Selected bond distances and angles are reported in Table 2. The
gold atom displays a tetrahedrally distorted square-planar co-
The diorganogold derivative [Au{N2C10H7(CMe2C6H4)-
6}(C2Ph)][PF6] 22, on addition of PPh3 (molar ratio
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Table 2 Selected bond distances (Å) and angles (Њ) with estimated
standard deviations in parentheses for cation 18
Conclusion
Replacement of the chloride ligand in a series of C,N,N cyclo-
aurated complexes, although not straightforward in all cases,
may be carried out by means of different strategies depending
both on the nature of the C,N,N cyclometallated ligand or of
the incoming ligand YϪ.
Unprecedented gold() alkoxo complexes have been
obtained either from the chlorides by metathesis with sodium
alkoxides or by reaction of alcohols on acetato complexes. The
acetato and the alkoxo complexes can cleave the E–H (E = C, N
or S) bonds of moderately to weakly acidic compounds to give
thiolato, alkynyl and amido complexes under mild conditions.
Although exchange reactions of late transition metal complexes
have been extensively studied due to their involvement in
various stoichiometric and catalytic processes, up to now,
investigations on analogous gold() complexes have almost
been neglected. Further investigations will be devoted to ascer-
tain the potential of the new species reported.
Au–S
Au–N(2)
S–C(20)
2.292(1)
2.063(2)
1.792(5)
Au–N(1)
Au–C(15)
2.121(3)
2.014(4)
S–Au–N(1)
99.0(1)
93.0(1)
162.6(1)
100.9(1)
N(1)–Au–N(2)
N(2)–Au–C(15)
S–Au–N(2)
78.6(1)
91.2(1)
171.8(1)
S–Au–C(15)
N(1)–Au–C(15)
Au–S–C(20)
Experimental
General procedures
All starting materials were used as received from commercial
sources; the solvents were purified and dried according to
standard methods. Complexes 1[PF6]–3[PF6] were prepared as
Ϫ
reported previously;8 5–22 have been obtained as PF6 salts.
Elemental analyses were performed with a Perkin-Elmer
Elemental Analyzer 240B by Mr. A. Canu (Dipartimento di
Chimica, Università di Sassari). Conductivities were measured
with a Philips PW 9505 conductimeter. Infrared spectra were
recorded with a Perkin-Elmer 983 spectrophotometer using
Nujol mulls, 1H and 13C-{1H} NMR spectra with a Varian
VXR 300 spectrometer operating at 299.9 and 75.4 MHz,
respectively; the 2-D experiments were performed by means of
COSY-90. Chemical shifts are given in ppm relative to internal
tetramethylsilane. Mass spectra were obtained with a VG 7070
instrument operating under FAB conditions, with 3-nitrobenzyl
alcohol as supporting matrix unless otherwise stated.
Fig. 1 An ORTEP view of the cation in complex 18[PF6]. Thermal
ellipsoids are drawn at the 30% probability level.
ordination, with maximum deviations from the best plane of
ϩ0.208(3) Å for N(2) and Ϫ0.200(3) Å for N(1). The dihedral
angle between the Au–N(1)–N(2) and Au–S–C(15) planes is
16.0(2)Њ. The Au–S distance, 2.292(1) Å, is statistically coin-
cident with that found in [Au(C,N,C)(Spy-2)], 2.296(2) Å
(HC,N,CH = 2,6-diphenylpyridine).4c Bond parameters involv-
ing the present C,N,N terdentate ligand can be compared with
those found in cation [Au{N2C10H7(CMe2C6H4)-6}Cl]ϩ 3,8
which differs from the present one only in the replacement of
the thiolate with a chloride ligand. The Au–N(1) and Au–C(15)
bond lengths observed here, 2.121(3) and 2.014(4) Å, respect-
ively, compare well with those found in 3, 2.121(5) and 2.009(6)
Å, respectively. The present Au–N(2) distance, 2.063(2) Å, is
longer than that found in 3, 2.009(4) Å, probably due to the
higher trans influence of the thiolate ligand with respect to that
of the chloride. The bites of the terdentate ligand are also very
similar (N(1)–Au–N(2) 78.6(1)Њ here and 79.5(2)Њ in 3, N(2)–
Au–C(15) 91.2(1)Њ here and 91.3(2)Њ in 3). The six-membered
metallacycle is in a boat conformation, with atoms N(2), C(10),
C(14) and C(15) nearly coplanar [maximum deviations from
their best plane being ϩ0.012(3) Å for C(14) and Ϫ0.013(3) Å
for C(10)], whereas atoms Au and C(11) lie 0.635(1) and
0.646(4) Å above their best plane, respectively. One of the
hydrogen atoms (not refined) bonded to C(12) lies 2.54 Å from
the gold atom, a distance comparable to that found in 3, 2.62 Å,
and in [Au{NC5H4(CMe2C6H4)-2}Cl2], 2.56 Å.5b These short
metal–hydrogen interactions have been described by Crabtree
and co-workers21 as weak hydrogen bonds. The dihedral angle
between the best planes of the two pyridine rings is 14.0(1)Њ,
that between the best planes of rings N(2)–C(10) and C(14)–
C(19) is 54.7(1)Њ, and that between the metal co-ordination and
C(20)–C(25) best planes is 85.7(1)Њ.
Substitution reaction products
[Au{N2C10H7(CH2C6H4)-6}{CH2C(O)Me}][PF6] 5. To
a
stirred solution of complex 1[PF6] (0.093 g, 0.149 mmol) in
acetone (20 cm3) was added solid AgPF6 (0.040 g, 0.159 mmol);
the resulting suspension was stirred for 3 d at room temperature
and then filtered through Celite. Removal of solvent under
reduced pressure was followed by extraction with chloroform
(20 cm3) and filtration through Celite. Addition of diethyl
ether to the concentrated solution afforded a pale green solid
product. Recrystallization from dichloromethane–diethyl ether
yielded the analytical sample (0.068 g, 70%), mp 133–134 ЊC
{Found: C, 36.87; H, 2.65; N, 4.48%; Mϩ m/z 499. C20H18-
AuF6N2OP requires C, 37.28; H, 2.82; N, 4.35%; M 499 [Au-
(C,N,N){CH2C(O)Me}ϩ]};ΛM (5 × 10Ϫ4 moldmϪ3, Me2CO)130
Ω
Ϫ1 cm2 molϪ1; νmax/cmϪ1 1681 (C᎐O), 1604, 1227, 843 and 778.
᎐
[Au{N2C10H7(CHMeC6H4)-6}{CH2C(O)Me}][PF6] 6. The
procedure was similar to that for complex 5. Yield 80%, mp
122–124 ЊC {Found: C, 37.90; H, 2.93; N, 4.25%; Mϩ m/z 513.
C21H20AuF6N2OP requires C, 38.31; H, 3.06; N, 4.26%; M 513
[Au(C,N,N){CH2C(O)Me}ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3
,
Me2CO) 120 ΩϪ1 cm2 molϪ1; νmax/cmϪ1 1678 (C᎐O), 1603, 1224,
᎐
841 and 780.
[Au{N2C10H7(CMe2C6H4)-6}{CH2C(O)Me}][PF6] 7. The
procedure was similar to that for 5. Yield 85%, mp 141–142 ЊC
{Found: C, 39.29; H, 3.30; N, 4.15%; Mϩ m/z 527. C22H22-
AuF6N2OP requires C, 39.30; H, 3.30; N, 4.17%; M 527
[Au(C,N,N){CH2C(O)Me}ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3
,
J. Chem. Soc., Dalton Trans., 1999, 2823–2831
2827

View Article Online
Me2CO) 120 ΩϪ1 cm2 molϪ1; νmax/cmϪ1 1679 (C᎐O), 1599, 1226,
843 and 778.
[Au{N2C10H7(CHMeC6H4)-6}(OMe)][PF6] 13. A solution of
᎐
complex 8 (0.219 g, 0.332 mmol) in methanol (25 cm3) was
stirred for 24 h at room temperature. The white precipitate
which was formed during this period was filtered off and
washed with diethyl ether to give a first crop (0.091 g). The
mother-liquor was concentrated to small volume and diethyl
ether added to give a precipitate of a mixture of unchanged 8
and 13 (1H NMR criterion). The mixture was dissolved in
methanol and stirred for 48 h and then worked up to give a
second crop of 13 (0.061 g). Yield 72%, mp 193–195 ЊC {Found:
C, 35.85; H, 3.08; N, 4.26%; Mϩ m/z 487. C19H18AuF6-
N2OP requires C, 36.09; H, 2.87; N, 4.43%; M 487 [Au-
(C,N,N)(OMe)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, CH2Cl2) 30 ΩϪ1 cm2
molϪ1; νmax/cmϪ1 2798, 1601, 1578, 1568, 1028, 1016 (C–O), 845
and 787.
[Au{N2C10H7(CHMeC6H4)-6}(O2CMe)][PF6] 8. To a stirred
solution of complex 2[PF6] (0.339 g, 0.532 mmol) in acetone
(25 cm3) was added solid AgO2CMe (0.098 g, 0.587 mmol); the
resulting suspension was stirred for 3 h at room temperature
and then filtered through Celite. Removal of solvent under
reduced pressure was followed by extraction with dichloro-
methane (20 cm3) and filtration through Celite. Addition of
diethyl ether to the concentrated solution afforded a pale yellow
solid product. Recrystallization from dichloromethane–diethyl
ether yielded the analytical sample (0.281 g, 80%), mp 173–
174 ЊC {Found: C, 36.18; H, 2.80; N, 4.21%; Mϩ m/z 515.
C20H18AuF6N2O2P requires C, 36.38; H, 2.75; N, 4.24%; M 515
[Au(C,N,N)(O2CMe)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, Me2CO) 138
ΩϪ1 cm2 molϪ1; νmax/cmϪ1 1666 (CO2), 1602, 1564, 1270 (CO2),
840 and 779.
[Au{N2C10H7(CHMeC6H4)-6}(OEt)][PF6] 14. A solution of
complex 8 (0.100 g, 0.151 mmol) in dichloromethane (5 cm3)
was added dropwise to 25 cm3 of ethanol; the resulting solution
was stirred for 48 h at room temperature and then concentrated
to small volume. Addition of diethyl ether gave a white pre-
cipitate of the equilibrium mixture (1H NMR criterion). The
mixture was subjected to the procedure described above until
complete conversion of 8 had occurred. Yield 0.063 g (65%),
mp 182 ЊC (decomp.) {Found: C, 36.83; H, 2.95; N, 4.42%; Mϩ
m/z 501. C20H20AuF6N2OP requires C, 37.17; H, 3.12; N, 4.33%;
M 501 [Au(C,N,N)(OEt)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, CH2Cl2)
36 ΩϪ1 cm2 molϪ1; νmax/cmϪ1 1603, 1580, 1045, 1028 (C–O), 838
and 785.
[Au{N2C10H7(CMe2C6H4)-6}(O2CMe)][PF6] 9. The pro-
cedure was similar to that for complex 8. Yield 82%, mp
201–202 ЊC {Found: C, 37.20; H, 3.11; N, 4.08%; Mϩ m/z 529.
C21H20AuF6N2O2P requires C, 37.40; H, 2.99; N, 4.15%; M 529
[Au(C,N,N)(O2CMe)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, Me2CO) 148
Ω
Ϫ1 cm2 molϪ1; νmax/cmϪ1 1669 (C᎐O), 1601, 1562, 1264 (C–O),
᎐
835 and 783.
[Au{N2C10H7(CH2C6H4)-6}(acac)][PF6] 10. To a stirred sus-
pension of complex 1[PF6] (0.176 g, 0.282 mmol) in dichloro-
methane (20 cm3) was added a solution of Tl(acac) (0.092 g,
0.303 mmol) in the same solvent; the resulting suspension was
stirred for 4 h at room temperature and then filtered through
Celite. The filtered solution was concentrated to small volume;
addition of diethyl ether gave a pale yellow solid product which
was recrystallized from dichloromethane–diethyl ether. Yield
119 mg (61%), mp 178 ЊC (decomp.) {Found: C, 38.10; H, 2.31;
N, 3.84%; Mϩ m/z 541. C22H20AuF6N2O2P requires C, 38.50; H,
2.94; N, 4.08%; M 541 [Au(C,N,N)(acac)ϩ]}; ΛM (5 × 10Ϫ4 mol
dmϪ3, Me2CO) 140 ΩϪ1 cm2 molϪ1; νmax/cmϪ1 3641 (O–H), 1674
[Au{N2C10H7(CMe2C6H4)-6}(OMe)][PF6] 15. To a stirred
suspension of complex 3[PF6] (0.207 g, 0.318 mmol) in meth-
anol (30 cm3) was added a solution of MeONa (0.052 g, 0.954
mmol) in the same solvent; the resulting pale yellow solution
was stirred for 1 h at room temperature. Removal of sol-
vent under reduced pressure was followed by extraction with
dichloromethane (20 cm3) and filtration through Celite. Addi-
tion of diethyl ether to the concentrated solution afforded a
pink product: yield 0.145 g (70%), mp 205–206 ЊC {Found: C,
36.87; H, 3.23; N, 4.19%; Mϩ m/z 501. C20H20AuF6N2OP
requires C, 37.17; H, 3.12; N, 4.33%; M 501 [Au(C,N,N)-
(C᎐O), 1600, 1577, 840 and 777.
᎐
(OMe)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, Me2CO) 140 ΩϪ1 cm2 molϪ1
;
[Au{N2C10H7(CHMeC6H4)-6}(acac)][PF6] 11. The procedure
was similar to that for complex 10. Yield 90%, mp 194–196 ЊC
{Found: C, 39.08; H, 3.15; N, 3.94%; Mϩ m/z 555. C23H22-
AuF6N2O2P requires C, 39.44; H, 3.17; N, 4.00%; M 555
[Au(C,N,N)(acac)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, Me2CO) 145 ΩϪ1
νmax/cmϪ1 2798, 1599, 1576, 1024 (C–O), 843 and 782;
δC(CD2Cl2) 165.8, 156.0, 153.2, 139.9 and 138.2 (aromatic C),
147.2, 145.2, 144.3, 131.8, 129.3, 128.9, 128.8, 125.8, 125.7,
125.5 and 124.1 (aromatic CH), 62.9 (MeO), 50.7 (CMe2) and
32.6 (Me2C).
cm2 molϪ1; νmax/cmϪ1 3646 (O–H), 1709 and 1676 (C᎐O), 1601,
᎐
1578, 841 and 776.
[Au{N2C10H7(CMe2C6H4)-6}(OEt)][PF6] 16. To a stirred sus-
pension of complex 3[PF6] (0.118 g, 0.181 mmol) in ethanol (20
cm3) was added a solution of EtONa (0.038 g, 0.558 mmol) in
the same solvent; the resulting pale yellow solution was stirred
for 90 min at room temperature. Removal of solvent under
reduced pressure was followed by extraction with dichloro-
methane (20 cm3) and filtration through Celite. Addition of
diethyl ether to the concentrated solution afforded a pale yellow
product: yield 0.088 g (72%), mp 183 ЊC (decomp.) {Found: C,
37.91; H, 3.15; N, 4.18%; Mϩ m/z 515. C21H22AuF6N2OP
requires C, 38.20; H, 3.36; N, 4.24%; M 515 [Au(C,N,N)-
[Au{N2C10H7(CMe2C6H4)-6}(acac)][PF6] 12. The procedure
was similar to that for complex 10. Yield 85%, mp 181 ЊC
(decomp.) {Found: C, 39.90; H, 3.19; N, 3.63%; Mϩ m/z 569.
C24H24AuF6N2O2P requires C, 40.35; H, 3.39; N, 3.92%; M 569
[Au(C,N,N)(acac)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, Me2CO) 140 ΩϪ1
cm2 molϪ1; νmax/cmϪ1 3646 (O–H); 1695, 1676 (C᎐O); 1598,
᎐
1578, 840 and 778.
[Au{N2C10H7(C(OH)MeC6H4)-6}(OMe)][PF6] 13*. To
a
stirred suspension of complex 2[PF6] (0.096 g, 0.15 mmol) in
methanol (20 cm3) was added a solution of MeONa (0.016 g,
0.3 mmol) in the same solvent; the resulting greenish solution
was stirred for 1 h at room temperature. Removal of sol-
vent under reduced pressure was followed by extraction with
dichloromethane (15 cm3) and filtration through Celite. Addi-
tion of diethyl ether to the concentrated solution afforded a
white product: yield 0.050 g (51%), mp 221–222 ЊC {Found: C,
35.25; H, 3.08; N, 4.20%; Mϩ m/z 503. C19H18AuF6N2O2P
requires C, 35.20; H, 2.80; N, 4.32%; M 503 [Au(C,N,N*)-
(OEt)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, Me2CO) 144 ΩϪ1 cm2 molϪ1
;
νmax/cmϪ1 1601, 1578, 1046, 1027 (C–O), 836 and 784;
δC(CD2Cl2) 165.6, 156.0, 153.3, 139.9 and 138.3 (aromatic C),
147.1, 145.2, 144.3, 131.9, 129.3, 128.9, 128.8, 125.8, 125.7,
125.5 and 124.1 (aromatic CH), 69.3 (CH2O), 50.7 (CMe2), 32.5
(Me2C) and 21.5 (MeCH2O).
[Au{N2C10H7(CHMeC6H4)-6}(SPh)][PF6] 17. Method (a).
To a stirred solution of complex 8 (0.102 g, 0.154 mmol) in
dichloromethane (20 cm3) was added PhSH (0.051 g, 0.462
mmol); the solution changed immediately from pale yellow to
orange. After stirring for 1 h at room temperature it was con-
(OMe)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, Me2CO) 135 ΩϪ1 cm2 molϪ1
;
νmax/cmϪ1 3629 (O–H), 1600, 1576, 1558, 1025 (C-O), 845 and
781.
2828
J. Chem. Soc., Dalton Trans., 1999, 2823–2831

View Article Online
centrated to small volume; addition of diethyl ether afforded an
orange crystalline product: yield 0.98 g (89%).
ether gave a pale yellow solid product. Recrystallization from
dichloromethane–diethyl ether gave the analytical sample: yield
0.105 g (82%), mp 194–196 ЊC {Found: C, 44.95; H, 3.25; N,
3.81%; Mϩ m/z 571. C27H22AuF6N2P requires C, 45.27; H, 3.10;
N, 3.91%; M 571 [Au(C,N,N)(C2Ph)ϩ]}; ΛM (5 × 10Ϫ4 mol
dmϪ3, CH2Cl2) 33 ΩϪ1 cm2 molϪ1; νmax/cmϪ1 1599, 1563, 842,
812, 783 and 697 (Ph).
Method (b). The procedure was similar to that in (a) except
complex 13 (0.095 g, 0.15 mmol) was used in place of 8. Yield
85%, mp 130–132 ЊC {Found: C, 39.95; H, 2.81; N, 3.55%; Mϩ
m/z 565. C24H20AuF6N2PS requires C, 40.58; H, 2.84; N, 3.94%;
M 565 [Au(C,N,N)(SPh)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, CH2Cl2)
32 ΩϪ1 cm2 molϪ1, νmax/cmϪ1 1599, 1574, 842, 778, 746 and 692
(Ph).
Reaction of [Au{N2C10H7(CMe2C6H4)-6}(C2Ph)][PF6] 22 with
PPh3. To a stirred solution of complex 22 (0.080 g, 0.112 mmol)
in dichloromethane (20 cm3) was added a solution of PPh3
(0.059 g, 0.224 mmol) in the same solvent. The reaction was
carried out under an argon atmosphere. The resulting solution
was stirred for 24 h and then concentrated to small volume;
addition of diethyl ether afforded a white precipitate which was
identified as [Au(PPh3)2][PF6] (0.078 g, 80%). The mother-
liquor was evaporated to dryness and extracted with n-pentane.
Removal of the solvent under reduced pressure gave a white
solid which was purified by chromatography on a column
(47 × 2 cm) of silica gel (Merck, 70–230 mesh ASTM) using
n-hexane–dichloromethane (1:5) as eluent. Removal of the
solvent yielded the C–C coupling product N2C10H7{CMe2-
C6H4(C2Ph)-2Љ}-6 23 as a white solid: yield 80%, mp 169–
170 ЊC (Found: C, 86.45; H, 6.01; N, 7.26%; M Ϫ H m/z 373
(EI). C27H22N2 requires C, 86.60; H, 5.92; N, 7.48% M 374);
νmax/cmϪ1 1595, 1578, 1562, 1490, 1440, 1422, 1401, 1258, 1160,
1151, 1126, 1071, 1044, 1006, 989, 923, 828, 783, 754, 692, 662,
622 and 610 (Nujol); δH(CDCl3) 8.63 (ddd, 1 H, H6Ј), 8.50 (dt,
1 H, H3Ј), 8.15 (dd, 1 H, H3), 7.77 (td, 1 H, H4Ј), 7.67 (dd, 1 H, H3Љ
or H6Љ), 7.59 (t, 1 H, H4), 7.51 (dd, 1 H, H6Љ or H3Љ), 7.41 (td,
1 H, H4Љ or H5Љ), 7.27 (2td, 2 H, H5Љ or H4Љ and H5Ј), 7.03 (tt,
[Au{N2C10H7(CMe2C6H4)-6}(SPh)][PF6] 18. The procedures
were similar to those for complex 17. Yield 80–85%, mp 176–
178 ЊC {Found: C, 40.94; H, 2.97; N, 3.85%; Mϩ m/z 579.
C25H22AuF6N2PS: C, 41.45; H, 3.06; N, 3.87%; M 579 [Au-
(C,N,N)(SPh)ϩ]}; ΛM (5 × 10Ϫ4 mol dmϪ3, CH2Cl2) 34 ΩϪ1 cm2
molϪ1; νmax/cmϪ1 1606, 1572, 836, 782, 749 and 689 (Ph). Crys-
tals of 18[PF6] were obtained by slow diffusion of diethyl ether
into a dichloromethane solution.
[Au{N2C10H7(CHMeC6H4)-6}(NHC6H4NO2-4)][PF6] 19. To
a stirred solution of complex 13 (0.122 g, 0.193 mmol) in
dichloromethane (20 cm3) was added solid H2NC6H4NO2-4
(0.081 g, 0.586 mmol); the resulting yellow solution was stirred
for 16 h. During this period an orange-yellow precipitate was
formed, which was filtered off and washed with dichloro-
methane to give the analytical sample: yield 0.114 g (80%),
mp 178–180 ЊC {Found: C, 36.25; H, 2.38; N, 6.65%; Mϩ m/z
593. C24H20AuF6N4O2PؒCH2Cl2 (the presence of CH2Cl2 was
confirmed by NMR spectroscopy) requires C, 36.47; H, 2.69;
N, 6.81%; M 593 [Au(C,N,N)(NHC6H4NO2-4)ϩ]}; ΛM (5 ×
10Ϫ4 mol dmϪ3, (CH3)2CO) 138 ΩϪ1 cm2 molϪ1; νmax/cmϪ1 3350
(N–H), 1601, 1581 (NO2), 1277 (NO2), 1109, 862 and 834.
6ٞ
1 H, H4ٞ), 6.99 (dd, 2 H, H2ٞ, ), 6.93 (dd, 1 H, H5), 6.88 (tt,
5ٞ
2 H, H3, ) and 1.92 (s, 6 H, 2Me) (COSY); δC(CDCl3) 168.1,
[Au{N2C10H7(CMe2C6H4)-6}(NHC6H4NO2-4)][PF6] 20. The
procedure was similar to that for complex 19 except for the
reaction time which was 2 d. Yield 75–80%, mp 178–179 ЊC
(decomp.) {Found: C, 37.53; H, 2.58; N, 6.89%; Mϩ m/z 607.
C25H22AuF6N4O2P.CH2Cl2 (the presence of CH2Cl2 was con-
firmed by NMR spectroscopy) requires C, 37.29; H, 2.89; N,
6.69%; M 607 [Au(C,N,N)(NHC6H4NO2-4)ϩ]}; ΛM (5 × 10Ϫ4
mol dmϪ3, (CH3)2CO) 130 ΩϪ1 cm2 molϪ1; νmax/cmϪ1 3352
(N–H), 1602, 1585 (NO2), 1285 (NO2), 1110, 857 and 846;
δC{(CD3)2CO)} 165.5, 160.8, 160.0, 157.9, 141.6 and 136.2
(aromatic C, C,N,N and NHC6H4NO2), 148.8, 145.9, 144.8,
134.4, 129.6, 129.2, 128.9, 127.1, 126.2, 126.1 and 124.4
(aromatic CH, C,N,N), 126.8 and 117.2 (CH, NHC6H4NO2),
51.1 (CMe2) and 32.6 (Me2C).
156.8, 154.1, 150.4, 123.0 and 122.9 (aromatic C), 148.8, 136.8,
136.6, 134.4, 131.0, 128.2, 127.7, 127.6, 126.3, 126.2, 123.2,
᎐
121.6, 121.2 and 117.5 (aromatic CH), 95.3 and 89.3 (C᎐C),
᎐
47.0 (CMe2) and 29.3 (Me2C); m/z (%) 373 (50, M Ϫ H), 359
(100, M Ϫ Me), 282 (7, M Ϫ Me Ϫ Ph), 179 (10, Ph2C2 ϩ H),
155 (8, bipy Ϫ H), 149 (50) and 78 (11) (EI).
[Au{N2C10H7(CHMeC6H4)-6}(C2Ph)][PF6] 21. To a stirred
suspension of complex 13 (0.0843 g, 0.133 mmol) [or 14 (0.052
g, 0.08 mmol)] in benzene (20 cm3) was added dichloromethane
until a solution was obtained, and then PhC2H (0.045 cm3,
d = 0.930 g cmϪ3, 0.399 mmol). The resulting solution was
stirred for 30 h at room temperature and then concentrated to
small volume; addition of diethyl ether gave a white precipitate
of [Au2{N2C10H7(CHMeC6H4)-6}2(µ-O)][PF6]2 (0.050 g). The
mother-liquor was evaporated to dryness and then extracted
with n-hexane; the whitish residue insoluble in n-hexane was
collected by filtration under vacuum to give the analytical
sample: yield 0.010 g (10%), mp 213 ЊC (decomp.) (Found: C,
44.65; H, 2.98; N, 3.78. C26H20AuF6N2P requires C, 44.46; H,
2.87; N, 3.99%); IR (Nujol) νmax/cmϪ1 1600, 1563, 844, 778 and
689 (Ph).
Reactions of [Au(C,N,N)Cl][PF6] with MeCO2Na. (a) To a
stirred solution of complex 2 (0.096 g, 0.15 mmol) in acetone
(20 cm3) was added a solution of MeCO2Na (0.037 g, 0.45
mmol) in the same solvent; the resulting solution was stirred for
2 h at room temperature. Removal of solvent under reduced
pressure was followed by extraction with dichloromethane
(20 cm3) and filtration through Celite. Addition of diethyl ether
to the concentrated solution afforded a creamy product which
analysed for [Au{N2C10H7(C(OH)MeC6H4)-6}Cl][PF6] 2*:
yield 0.098 g (70%), mp 172–173 ЊC {Found: C, 33.24; H, 2.56;
N, 4.16%; Mϩ m/z 507. C18H15AuClF6N2O requires C, 33.12; H,
2.32; N, 4.29%; M 507 [Au(C,N,N*)Clϩ]}; ΛM (5 × 10Ϫ4 mol
dmϪ3, (CH3)2CO) 136 ΩϪ1 cm2 molϪ1 νmax/cmϪ1 3633, 3564
(O–H), 1600, 1559, 1019, 843, 778 and 369 (Au–Cl). δH(CD2Cl2)
9.37 (dd, 1H, H6Ј), 8.63–7.17 (m, 10 H, aromatics), 3.88 [s
(broad), 1 H, OH] and 2.18 (s, 3 H, Me); δC(CD2Cl2) 163.4,
155.8, 153.6, 137.2, 133.5 (aromatic C), 148.6, 146.3, 135.5,
130.1, 129.4, 129.3, 126.9, 126.5, 125.8, 125.2 (aromatic CH),
82.7 [C(OH)Me] and 36.4 (Me).
[Au{N2C10H7(CMe2C6H4)-6}(C2Ph)][PF6] 22. To a stirred
suspension of complex 15 (0.115 g, 0.178 mmol) in benzene (20
cm3) was added dichloromethane until a solution was obtained,
and then PhC2H (0.06 cm3, d = 0.930 g cmϪ3, 0.534 mmol). The
resulting solution was stirred for 20 h at room temperature
and then concentrated to small volume; addition of diethyl
(b) Complex 3 (0.098 g, 0.15 mmol) was treated with
J. Chem. Soc., Dalton Trans., 1999, 2823–2831
2829

View Article Online
(SADABS22b) to the 22847 collected reflections. The calcu-
Table 3 Crystallographic data for complex 18 [PF6]
lations were performed on an AST Power Premium 486/33
computer using the Personal Structure Determination Pack-
age23 and the physical constants tabulated therein. Scattering
factors and anomalous dispersion corrections were taken from
ref. 24. The structure was refined by full-matrix least squares
using all reflections and minimizing the function Σw(Fo2 Ϫ
kFc2)2 (refinement on F2). Anisotropic thermal factors were
refined for all the non-hydrogen atoms. The hydrogen atoms
were placed in their ideal positions (C–H 0.97 Å, B 1.15 times
those of the carbon atoms to which they are attached) and not
refined. In the final Fourier-difference map the maximum
residual was 0.70(13) e ÅϪ3 at 1.36 Å from F(2).
Formula
M
Colour
Crystal system
Space group
a/Å
C25H22AuF6N2PS
724.46
Yellow
Trigonal (hexagonal indexing)
¯
R3 (no. 148)
41.018(4)
8.215(1)
11970(2)
18
298
57.1
c/Å
U/Å3
Z
T/K
µ(Mo-Kα)/cmϪ1
Measured reflections
(total; independent)
Rint
22847; 5912
CCDC reference number 186/1538.
0.029
0.038, 0.057
0.037
Final R2 and R2w indices (F2)
Conventional R1
Acknowledgements
Financial support from Ministero dell’Università e della
Ricerca Scientifica e Tecnologica (MURST) (40%) is gratefully
acknowledged.
MeCO2Na (0.037 g, 0.45 mmol) by a procedure similar to (a)
for 20 h. The isolated product was a 6:1:1 mixture of 3, 7 and 9
(1H NMR criterion).
(c) To a stirred suspension of complex 2 (0.105 g, 0.165
mmol) in acetonitrile–water (25 cm3) was added solid MeCO2-
Na (0.041 g, 0.495 mmol). The resulting mixture was refluxed
for 12 h during which a solution was obtained. After the solu-
tion was cooled to room temperature a white solid separated;
it was filtered off, dried under vacuum and identified as
unchanged 2 (0.040 g). The mother-liquor was evaporated to
dryness and extracted with dichloromethane. The solution was
filtered through 1PS Whatman (silicone treated filter paper)
to remove traces of water and concentrated to small volume;
addition of diethyl ether afforded a pale yellow product (0.045
g). It was identified as a 2.5:1 mixture of 2 and [Au2(C,N,N)2-
(µ-O)][PF6]2 (1H NMR criterion).
(d) Complex 3 (0.104 g, 0.160 mmol) was treated with
MeCO2Na (0.039 g, 0.48 mmol) by a procedure similar to (c).
Unchanged 3 (0.054 g) was recovered after the reaction mixture
was cooled to room temperature. A 1:1:2 mixture of 3,
[Au2(C,N,N)2(µ-O)][PF6]2 and an unidentified compound was
isolated after working up the mother-liquor.
References
1 J. P. Collman, L. S. Hegedus, J. R. Norton and R. G. Finke,
Principles and Applications of Organotransition Metal Chemistry,
University Science Books, Mill Valley, CA, 2nd edn., 1987, pp
235–278.
2 R. V. Parish, Gold Bull., 1997, 30, 3; 55; 1998, 31, 14.
3 (a) S. Komiya, T. Sone, Y. Usui, M. Hirano and A. Fukuoka, Gold
Bull., 1996, 29, 131; (b) Q. Xu, Y. Imamura, M. Fujiwara and
Y. Souma, J. Org. Chem., 1997, 62, 1594; (c) T. J. Mathieson, A. G.
Langdon, N. B. Milestone and B. K. Nicholson, Chem. Commun.,
1998, 371; (d) J. H. Teles, S. Brode and M. Chabanas, Angew. Chem.,
Int. Ed., 1998, 37, 1415; (e) M. Bartz, J. Küther, R. Seshadri and
W. Tremel, Angew. Chem., Int. Ed., 1998, 37, 2466.
4 Recent papers: (a) J. Vicente, M. T. Chicote, M. I. Lozano and
S. Huertas, Organometallics, 1999, 18, 753; (b) M. B. Dinger and
W. Henderson, J. Organomet. Chem., 1999, 577, 219; (c) K.-H.
Wong, K. K. Cheung, M. C.-W. Chan and C.-M. Che, Organo-
metallics, 1998, 17, 3505; (d) M. B. Dinger and W. Henderson,
J. Organomet. Chem., 1998, 560, 233; (e) M. B. Dinger,
W. Henderson, B. K. Nicholson and W. T. Robinson, J. Organomet.
Chem., 1998, 560, 169; (f) M. B. Dinger and W. Henderson,
J. Organomet. Chem., 1998, 557, 231; (g) M. B. Dinger and
W. Henderson, J. Organomet. Chem., 1998, 547, 243; (h) K. Ortner
and U. Abram, Inorg. Chem. Commun., 1998, 1, 251; (i) M. A.
Mansour, R. J. Lachicotte, H. J. Gysling and R. Eisenberg, Inorg.
Chem., 1998, 37, 4625; (j) Y. Fuchita, H. Ieda, A. Kayama,
J. Kinoshita-Nagaoka, H. Kawano, S. Kameda and M. Mikuriya,
J. Chem. Soc., Dalton Trans., 1998, 4095; (k) U. Abram, J. Mack,
K. Ortner and M. Müller, J. Chem. Soc., Dalton Trans., 1998, 1011;
(l) Y. Fuchita, H. Ieda, Y. Tsunemune, J. Kinoshita-Nagaoka
and H. Kawano, J. Chem. Soc., Dalton Trans., 1998, 791; (m)
M. Nonoyama, K. Nakajima and K. Nonoyama, Polyhedron, 1997,
16, 4039.
5 (a) J. Vicente, M.-D. Bermúdez, F.-J. Carrión and P. G. Jones, Chem.
Ber., 1996, 129, 1395; (b) M. A. Cinellu, A. Zucca, S. Stoccoro,
G. Minghetti, M. Manassero and M. Sansoni, J. Chem. Soc., Dalton
Trans., 1996, 2865; (c) J. Vicente, M. D. Bermúdez and F. J. Carrión,
Inorg. Chim. Acta, 1994, 220, 1 and refs. therein; (d) J. Vicente,
M.-D. Bermúdez and J. Escribano, Organometallics, 1991, 10, 3380
and refs. therein.
6 H.-Q. Liu, T.-C. Cheung, S.-M. Peng and C.-M. Che, J. Chem. Soc.,
Chem. Commun., 1995, 1787; C.-W. Chan, W.-T. Wong and C.M.
Che, Inorg. Chem., 1994, 33, 1266.
7 R. V. Parish, B. P. Howe, J. P. Wright, J. Mack, R. G. Pritchard,
R. G. Buckley, A. M. Elsome and S. P. Fricker, Inorg. Chem., 1996,
35, 1659; R. V. Parish, J. Mack, L. Hargreaves, J. P. Wright, R. G.
Buckley, A. M. Elsome, S. P. Fricker and B. R. C. Theobald,
J. Chem. Soc., Dalton Trans., 1996, 69.
8 M. A. Cinellu, A. Zucca, S. Stoccoro, G. Minghetti, M. Manassero
and M. Sansoni, J. Chem. Soc., Dalton Trans., 1996, 4217.
9 J. Strähle, in Gold. Progress in Chemistry, Biochemistry and
Technology, ed. H. Schmidbaur, Wiley, Chichester, 1999, ch.11,
pp. 339–342.
10 M. A. Cinellu, G. Minghetti, M. V. Pinna, S. Stoccoro, A. Zucca and
M. Manassero, Chem. Commun., 1998, 2397.
11 K. Nakamoto, Infrared and Raman Spectra of Inorganic and
Coordination Compounds, John Wiley, New York, 5th edn., 1997.
Reactions of complex 2 with KOH. (a) To a stirred solution of
complex 2 (0.100 g, 0.157 mmol) in acetone (20 cm3) was added
an aqueous solution of KOH (0.009 g, 0.160 mmol); the result-
ing solution was stirred for 4 h at room temperature. Removal
of solvent under reduced pressure was followed by extraction
with dichloromethane (20 cm3), filtration through 1PS What-
man and then through Celite. Addition of diethyl ether to the
concentrated solution afforded a beige product (0.040 g) which
was identified as a 3:3.5:4 mixture of 2, [Au2(C,N,N)2(µ-O)]-
[PF6]2 and 6 (1H NMR criterion).
(b) To a stirred suspension of complex 2 (0.100 g, 0.157
mmol) in methanol (20 cm3) was added an aqueous solution of
KOH (0.009 g, 0.160 mmol); the resulting blue solution was
stirred for 4 h at room temperature then treated as above. Addi-
tion of diethyl ether to the concentrated pale yellow solution
afforded a whitish product (0.054 g) which was identified as a
3:8:1 mixture of 2, [Au2(C,N,N)2(µ-O)][PF6]2 and 13 (1H NMR
criterion).
X-Ray crystallography
Crystal data and other experimental details are summarized
in Table 3. The diffraction experiment was carried out on a
Siemens SMART CCD area-detector diffractometer. Cell
parameters and orientation matrix for complex 18[PF6] were
obtained from the least-squares refinement of 101 reflections
measured in three different sets of 15 frames each, in the
range 3 < θ < 23Њ. At the end of data collection no crystal decay
was observed. The collected frames were processed with the
software SAINT,22a and an absorption correction was applied
2830
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12 (a) S. Komiya and J. K Kochi, Inorg. Chem., 1977, 99, 3695; (b)
J. Vicente, M. D. Bermúdez, M.-T. Chicote and M.-J. Sánchez-
Santano, J. Chem. Soc., Chem. Commun., 1989, 141; (c) J. Vicente,
M. D. Bermúdez, M.-T. Chicote and M.-J. Sánchez-Santano,
J. Chem. Soc., Dalton Trans., 1990, 1945; (d) J. Vicente, M. D.
Bermúdez, J. Escribano, M. P. Carrillo and P. G. Jones, J. Chem.
Soc., Dalton Trans., 1990, 3083; (e) J. Vicente, M. D. Bermúdez,
M. P. Carrillo and P. G. Jones, J. Chem. Soc., Dalton Trans., 1992,
1975.
1977, 99, 8440; (e) S. Komiya, S. Ozaki and A. Shibue, J. Chem.
Soc., Chem. Commun., 1986, 1555; ( f) S. Komiya, S. Ochiai and
Y. Ishizaki, Inorg. Chem., 1992, 31, 3168; (g) S. Komiya, S. Ozaki,
I. Endo, K. Inoue, N. Kasuga and Y. Ishizaki, J. Organomet. Chem.,
1992, 433, 337.
17 J. K. Jawad, R. J. Puddephatt and M. A. Stalteri, Inorg. Chem., 1982,
21, 332; S. Komiya and A. Shibue, Organometallics, 1985, 4, 684.
18 S. Komiya, M. Ishikawa and S. Ozaki, Organometallics, 1988, 7,
2238; S. Komiya, T. Sone, S. Ozaki, M. Ishikawa and N. Kasuga,
J. Organomet. Chem., 1992, 428, 303.
19 J. A. J. Jarvis, A. Johnson and R. J. Puddephatt, J. Chem. Soc.,
Chem. Commun., 1973, 373.
13 Q. T. H. Le, S. Umetani, M. Suzuki and M. Matsui, J. Chem. Soc.,
Dalton Trans., 1997, 643; D. C. Nonhebel, Tetrahedron, 1968, 24,
1896.
14 H. E. Bryndza and W. Tam, Chem. Rev., 1988, 88, 1163.
15 J. Vicente, M. D. Bermúdez, F. J. Carrión and P. G. Jones,
J. Organomet. Chem., 1996, 508, 53; S. Komiya, M. Iwata, T. Sone
and A. Fukuoka, J. Chem. Soc., Chem. Commun., 1992, 1109;
T. Sone, M. Iwata, N. Kasuga and S. Komiya, Chem. Lett., 1991,
1949; B. R. Sutherland, K. Folting, W. E. Streib, D. M. Ho,
J. C. Huffman and K. G. Caulton, J. Am. Chem. Soc., 1987, 109,
3489; H. Schmidbaur, J. Adlkofer and A. Shiotani, Chem. Ber.,
1972, 105, 3389.
16 (a) A. Tamaki, S. A. Magennis and J. K. Kochi, J. Am. Chem. Soc.,
1974, 96, 6140; (b) S. Komiya, T. A. Albright, R. Hoffman and
J. K. Kochi, J. Am. Chem. Soc., 1976, 98, 7255; (c) S. Komiya and
J. K. Kochi, J. Am. Chem. Soc., 1976, 98, 7599; (d) S. Komiya,
T. A. Albright, R. Hoffman and J. K. Kochi, J. Am. Chem. Soc.,
20 C. K. Johnson, ORTEP, Report ORNL-5138, Oak Ridge National
Laboratory, Oak Ridge, TN, 1976.
21 W. Yao, O. Eisenstein and R. H. Crabtree, Inorg. Chim. Acta, 1997,
254, 105.
22 (a) SAINT, Reference manual, Siemens Energy and Automation,
Madison, WI, 1994–1996; (b) G. M. Sheldrick, SADABS, Empirical
Absorption Correction Program, University of Göttingen, 1997.
23 B. A. Frenz, Comput. Phys. 1988, 2, 42; Crystallographic Computing
5; Oxford University Press; Oxford, 1991, ch. 11, p. 126.
24 International Tables for X-Ray Crystallography, Kynoch Press,
Birmingham, 1974; vol. 4.
Paper 9/03925B
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2831