New arenediethynylgold(I) complexes. Crystal structures of [Ph3PAuC≡C(phenylendiyl-1,3)C≡CAuPPh3] and [Ph3PAuC≡C(mesitylendiyl-1,3)C≡CAuPPh3]

Article abstract of DOI:10.1016/S0020-1693(02)01443-3

By reacting the dialkynes HC≡C(Ar)C≡CH [Ar=1,3-C₆H₄ (mphen), 1,3-(C₆HMe₃-2,4,6) (mes), 1,4-(C₆Me₄-2,3,5,6) (dur)] with [AuClL] [L=dimethylsulfide (dms), tetrahydrothiophene (tht)] in the presence of an excess of Et₃N the polymeric complexes [AuC≡C(Ar)C≡CAu]_n [Ar=mphen (1), mes (2) dur (3)] were prepared. Upon reaction of these complexes with two equivalents of phosphine or isocyanide ligands (L), complexes [LAuC≡C(Ar)C≡CAuL] [Ar=mes, L=^tBuNC (4), XyNC (5); Ar=dur, L=PPh₃ (6), ^tBuNC (7)] were prepared in good yields. The complex [^tBuNCAuC≡C(mphen)C≡CAuCN^tBu] (8) was prepared by reaction of the corresponding diethynylarene with 2 equiv. of [AuCl(CN^tBu)] in the presence of NEt₃. By reacting the appropriate diethynylarene with 2 equiv. of [Au(acac)PPh₃], complexes [Ph₃PAuC≡C(Ar)C≡CAuPPh₃] [Ar=mphen (9), mes (10)] were prepared. The carbene complex [(^tBuNH)(Et₂N)CAuC≡C(mes)C≡CAuC(NH ^tBu)(NEt₂)] (11) was obtained by reacting the corresponding isocyanide complex 4 with diethylamine. The crystal structures of complexes 9 and 10 have been determined by X-ray diffraction studies. In both cases one of the gold atoms is in an essentially linear environment [CAuP: 176.95(14) (9), 177.19(8)° (10)] while the other CAuP bond angle is appreciably bent [170.07(11) (9), 171.22(8)° (10)].

Full text of DOI:10.1016/S0020-1693(02)01443-3

Inorganica Chimica Acta 347 (2003) 67ꢁ74
/
www.elsevier.com/locate/ica
New arenediethynylgold(I) complexes.
Crystal structures of [Ph3PAuCꢀC(phenylendiyl-1,3)Cꢀ
and [Ph3PAuCꢀC(mesitylendiyl-1,3)CꢀCAuPPh3]
/
/
CAuPPh3]
/
/
Jose´ Vicente a,*, Mar´ıa Teresa Chicote a, Miguel M. Alvarez-Falco´n a,
Mar´ıa-Dolores Abrisqueta a, Francisco J. Herna´ndez a, Peter G. Jones b
a Grupo de Qu´ımica Organometa´lica, Departamento de Qu´ımica Inorga´nica, Facultad de Qu´ımica, Universidad de Murcia, Apartado 4021,
Murcia 30071, Spain
b Institut fur Anorganische und Analytische Chemie der Technischen Universitat, Postfach 3329, 38023 Braunschweig, Germany
¨
¨
Received 30 March 2002; accepted 27 May 2002
Dedicated to Professor Rafael Uso´n in recognition of his leading role in organometallic chemistry
Abstract
By reacting the dialkynes HCꢀ
[AuClL] [Lꢀdimethylsulfide (dms), tetrahydrothiophene (tht)] in the presence of an excess of Et3N the polymeric complexes [AuCꢀ
C(Ar)CꢀCAu]n [Arꢀmphen (1), mes (2) dur (3)] were prepared. Upon reaction of these complexes with two equivalents of
phosphine or isocyanide ligands (L), complexes [LAuCꢀC(Ar)CꢀCAuL] [Arꢀ BuNC (4), XyNC (5); Arꢀdur, LꢀPPh3
mes, Lꢀt
(6), tBuNC (7)] were prepared in good yields. The complex [tBuNCAuCꢀ CAuCNtBu] (8) was prepared by reaction of
C(mphen)Cꢀ
the corresponding diethynylarene with 2 equiv. of [AuCl(CNtBu)] in the presence of NEt3. By reacting the appropriate
diethynylarene with 2 equiv. of [Au(acac)PPh3], complexes [Ph3PAuCꢀC(Ar)CꢀCAuPPh3] [Arꢀmphen (9), mes (10)] were
prepared. The carbene complex [(tBuNH)(Et2N)CAuCꢀ CAuC(NHtBu)(NEt2)] (11) was obtained by reacting the
C(mes)Cꢀ
/
C(Ar)Cꢀ
/
CH [Arꢀ
/
1,3-C6H4 (mphen), 1,3-(C6HMe3-2,4,6) (mes), 1,4-(C6Me4-2,3,5,6) (dur)] with
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
/
corresponding isocyanide complex 4 with diethylamine. The crystal structures of complexes 9 and 10 have been determined by
X-ray diffraction studies. In both cases one of the gold atoms is in an essentially linear environment [CAuP: 176.95(14) (9),
177.19(8)8 (10)] while the other CAuP bond angle is appreciably bent [170.07(11) (9), 171.22(8)8 (10)].
# 2002 Elsevier Science B.V. All rights reserved.
Keywords: Gold complexes; Diethynylarenes; X-ray crystal structures
1. Introduction
ing, nonlinear optical or liquid crystalline properties [1].
Diethynylarenegold(I) complexes of the types [AuCꢀ
C(Ar)CꢀCAu]n [2ꢁ4], [LAuCꢀC(Ar)CꢀCAuL], (Lꢀ
phosphine [3,5], isocyanide) [2,3], [AuCꢀC(Ar)Cꢀ
CAu(LL)]n, (LLꢀdiphosphines [1,3,4], diisocyanide
[2,3]), [ClAuPR2CH2PR2AuCꢀC(Ar)CꢀCAuPR2CH2-
PR2AuCl] [1] and [{AuCꢀC(Ar)CꢀCAu}2{CH2-
/
Polymeric species in which metal centers are bridged
/
/
/
/
/
/
/
by ꢁ
/
Cꢀ
/
C(Ar)Cꢀ
/
Cꢁ spacers (R being various groups
/
/
including aromatic rings) are attracting great attention
because some are known to display electrical conduct-
/
/
/
/
(PR2)2}2] [5] have been prepared, Ar groups including
C6H4-1,4, (C6H2Me2-2,5)-1,4 and C6H3Me-5-1,3. Most
such complexes have been obtained from the reaction of
[AuCl(SMe2)] with the appropriate dialkyne (2:1) in the
* Corresponding author. Fax: ꢂ
E-mail addresses: jvs@um.es
jones@xray36.anchem.nat.tu-bs.de (P.G. Jones).
/
34-968-364-143.
(J.
Vicente),
0020-1693/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved.
doi:10.1016/S0020-1693(02)01443-3

68
J. Vicente et al. / Inorganica Chimica Acta 347 (2003) 67ꢁ74
/
presence of base [1,2] or by the reactions of these
polymers with the appropriate ligands [6] although in
some cases special methods have been used [5]. In such
complexes, apart from some peculiar large ring struc-
tures [5], interesting photophysical properties [6,7] have
been found that are attributed in part [8ꢁ11] to the
/
existence of the short intermolecular Auꢀ ꢀ ꢀAu contacts
present in most of the structurally characterized lumi-
nescent gold(I) complexes [3,7,8,12]. Only three crystal
structures of arenediethynylgold(I) complexes have been
reported so far, namely those of [LAuCꢀ
CAuL] (Arꢀ1,4-(C6H2Me2-2,5), LꢀPMe3 [7], Arꢀ
3,5-C6H3Me, LꢀP(OMe)3, PMePh2) [3]. All three dis-
/
C(Ar)Cꢀ
/
/
/
/
/
play infinite chains of linear or angular digold molecules
associated by short Auꢀ ꢀ ꢀAu contacts. Additionally, in
the structure of the complex with LꢀPMePh2, parallel
/
ribbons form by interaction of two such chains.
Puddephatt has recently reviewed this chemistry [13].
Some diethynylgold(I) complexes have been reported
while this paper was being prepared [4,14].
We report here (i) the synthesis of diethynyldurene
and diethynylmesitylene, (ii) new arenediethynylgold(I)
complexes of the types [AuCꢀ
/
C(Ar)Cꢀ
/
CAu]n and
[LAuCꢀC(Ar)CꢀCAuL] derived from these diethynyl-
/
/
arenes and from the previously described diethynyl-1,3-
benzene and (iii) the crystal structures of two diethynyl-
arenegold(I) derivatives. None of these three diethynyl
groups are represented in the alkynylgold complexes
previously described.
2. Experimental
Chart 1.
2.1. Instrumentation, materials and reagents
2.2. X-ray structure determinations
The IR spectra, elemental analyses and melting point
determinations were carried out as described earlier [15].
Technical grade solvents were purified by standard
procedures. Unless otherwise stated, the reactions were
carried out at room temperature (r.t.) without special
precautions against moisture. The syntheses of the
Numerical data are presented in Table 1. Crystals
were mounted on glass fibres and transferred to the cold
gas stream of the diffractometer (Bruker Smart 1000
CCD). Data were recorded with Mo Ka radiation (lꢀ
/
˚
0.71073 A) in v- and f-scan mode. Absorption correc-
tions were applied on the basis of multiple scans
dialkynes HCꢀ
2,4,6); durꢀ1,4-(C6Me4-2,3,5,6) (see Chart 1), derived
from mesitylene and durene are described below, while
1,3-C6H4 [16] was previously
/
C(Ar)Cꢀ
/
CH [Arꢀ
/
mesꢀ/1,3-(C6HMe3-
/
(
SADABS). Structures were solved by the heavy-atom
method and refined anisotropically on F2 (SHELXL-97
[57]). Hydrogen atoms were included using a riding
model or with rigid methyl groups. To increase stability
of refinement, a system of restraints to local ring
geometry and light atom U values was employed in
each case. Special features of refinement: In compound
9, the residual electron density near the gold atoms is
high, probably because of an imperfect absorption
that for Arꢀ
/
mphenꢀ
/
described. The 1H and 31P{1H} NMR spectra were
recorded in CDCl3 with Varian Unity 300 or Bruker
AC-200 spectrometers. Chemical shifts, given in ppm,
are referred to TMS [1H, 13C{1H}] or H3PO4 [31P{1H}].
Molar conductivities were measured in acetone solution
(ca. 5ꢃ
/
10ꢄ4 mol lꢄ1) and are in the range 0ꢁ3 Vꢄ1
/
cm2 molꢄ1
.

J. Vicente et al. / Inorganica Chimica Acta 347 (2003) 67ꢁ
/74
69
Table 1
Crystallographic data
(15 ml) to give colorless needles. Yield 1.48 g, 62%. IR
(cmꢄ1): n(Cꢀ
1
C), 2146. H NMR (200 MHz): d 0.26 (s,
/
18H, SiMe3), 2.38 [s, 6H, Me (mes)], 2.55 [s, 3H, Me
(mes)], 6.88 [s, 1H, H (mes)].
9
10
Formula
fw
C46H34Au2P2
1042.60
¯
P1
C49H40Au2P2
1084.68
¯
P1
2.3.3. Synthesis of HCꢀ
/
C(mes)Cꢀ
/
CH
Space group
˚
A solution containing Me3SiCꢀ
/
C(mes)Cꢀ
/
CSiMe3
a (A)
˚
10.0219(10)
12.8300(12)
16.2393(16)
80.922(3)
75.008(3)
71.777(3)
1909.1(3)
2
9.9763(6)
12.9029(8)
17.0115(11)
81.654(3)
74.554(3)
71.257(3)
1994.5
2
(520 mg, 1.7 mmol) and KOH (100 mg, 1.8 mmol) in
MeOH (50 ml) was stirred at 50 8C for 6 h. The solution
was diluted with water (150 ml) and extracted with a
b (A)
˚
c (A)
a (8)
b (8)
g (8)
mixture of n-pentane and diethyl ether (1.7:1, 3ꢃ80
/
ml). The combined extracts were dried over anhydrous
MgSO4 for 0.5 h and filtered. The solution was
concentrated to dryness to give a bright yellow oil.
3
˚
V (A )
Z
rcalc (g cmꢄ3
)
1.814
7.791
1.806
7.461
133(2)
m (mmꢄ1
T (K)
)
Yield 230 mg, 81%. IR (cmꢄ1): n(ꢀ
/
Cꢁ
/
H), 3308; n(Cꢀ
/
C), 2102. 1H NMR (200 MHz): d 2.34 [s, 6H, Me (mes)],
2.53 [s, 3H, Me (mes)], 3.40 (s, 2H, CH), 6.85 [s, 1H, H
(mes)]. 13C{1H} NMR (50.3 MHz): d 19.6 (Me), 21.1
143(2)
0.0966
Rw (F2) a
R (F) b
0.0527
0.0221
1.6
0.0359
4.0
ꢄ3
˚
Dr (e A
)
(Me), 80.9 (C ꢀ
/
CH), 84.9 (Cꢀ
/
CH), 119.7, 128.0, 141.1,
a
wR2 (F2)ꢀ
/
[a{w(Fo2ꢄ
(aP)2ꢂ
bP, where Pꢀ
constants adjusted by the program.
/
Fc2)2}/a{w(Fo2)2}]0.5 for all reflections;
143.6 ppm.
w
ꢄ1ꢀ
/
s2(Fo2)ꢂ
/
/
/
[Fo2ꢂ2Fc2]/3 and a and b are
/
b
2.3.4. Synthesis of Me3SiCꢀ
To a suspension containing durI2 [17] (1.85 g, 4.80
mmol), [PdCl2(PPh3)2] (101 mg, 0.14 mmol) and CuI (62
/
C(dur)Cꢀ
/
CSiMe3
R1 (F)ꢀ
/
ajjFojꢄ
/
jFcjj/ajFoj for reflections with F ꢀ
/2s(F).
correction for an irregular plate. In compound 10, the
ring C41ꢁ46 is disordered over two positions, which
were refined isotropically with idealized geometry.
mg, 0.32 mmol) in NHEt2 (30 ml) was added Me3SiCꢀ
/
/
CH (1.5 ml, 10.56 mmol) under a nitrogen atmosphere
and the reaction mixture was stirred for 21 h. The
suspension was concentrated to dryness and the residue
2.3. Syntheses
extracted with n-pentane (4ꢃ50 ml). The combined
/
extracts were dried over anhydrous Na2SO4 for 1 h and
filtered. The solution was concentrated to ca. 150 ml and
chromatographed on neutral alumina using n-pentane
as eluent. The first effluent was collected and concen-
trated (10 ml) to give colorless needles. Yield 665 mg,
51%. 1H NMR (200 MHz): d 0.32 (s, 18H, SiMe3), 2.43
[s, 12H, Me (dur)].
2.3.1. Synthesis of mesI2
Mesitylene (2.8 ml, 20 mmol) was added to a
suspension containing I2 (5.1 g, 20 mmol) and
IPh(CF3CO2)2 [17] (9.5 g, 22 mmol) in CCl4 (30 ml).
The reaction mixture was stirred for 1.25 h and filtered
through Celite. The solution was concentrated under
vacuum almost to dryness and cold ethanol (ca. ꢄ
/
15 8C, 15 ml) was added. The resulting suspension
was filtered, and the white solid was washed with cold
EtOH and suction dried in the air. Yield 5.4 g, 73%.
M.p. 62 8C. H NMR (200 MHz): d 2.40 (s, 6H, Me);
2.91 (s, 3H, Me), 6.97 (s, 1H).
2.3.5. Synthesis of HCꢀ
To a solution of KOH (56 mg, 0.39 mmol) in H2O (12
ml) was added Me3SiCꢀC(dur)CꢀCSiMe3 (1.13 g, 3.47
mmol) and MeOH (60 ml). The reaction mixture was
heated at 80 8C for 10 h and left at r.t. overnight. It was
then treated with a saturated solution of NaCl in H2O
/
C(dur)Cꢀ
/
CH
/
/
1
2.3.2. Synthesis of Me3SiCꢀ
/
C(mes)Cꢀ
/
CSiMe3
To a solution containing mesI2 (2.83 g, 7.6 mmol),
(50 ml) and extracted with n-pentane (3ꢃ100 ml). The
/
extracts were dried over anhydrous Na2SO4 for 1 h and
filtered. The solution was concentrated to dryness to
give the crude title compound, which was purified by
sublimation onto a cold finger. Yield 550 mg, 87%.
[PdCl2(PPh3)2] (97 mg, 0.14 mmol) and CuI (56 mg, 0.3
mmol) in NHEt2 (50 ml) was added Me3SiCꢀ
29 mmol) under a nitrogen atmosphere and the reaction
mixture was stirred for 43 h. The reaction mixture was
concentrated under vacuum to dryness and the residue
/CH (4 ml,
M.p.: 102 8C. IR (cmꢄ1): n(ꢀ
/
Cꢁ
/
H), 3320, n(Cꢀ
/
C),
1
2162. H NMR (200 MHz): d 2.43 [s, 12H, Me (dur)],
3.56 (s, 2H, CH) ppm.
was extracted with diethyl ether (4ꢃ
/50 ml). The
combined extracts were dried over anhydrous Na2SO4
for 1 h and then filtered. The solution was concentrated
to ca. 130 ml and chromatographed through a neutral
Al2O3 column. The first yellow effluent was collected,
concentrated to dryness and recrystallized from EtOH
2.3.6. Synthesis of [AuCꢀ
/
C(Ar)Cꢀ
/
CAu] [Arꢀmphen
/
(1), mes (2), dur (3)]
The addition of triethylamine (1, 0.263 ml, 1.90 mmol;
2, 0.4 ml, 2.87 mmol; 3, 15 ml, 107 mmol) to a solution

70
J. Vicente et al. / Inorganica Chimica Acta 347 (2003) 67ꢁ74
/
containing the appropriate diethynylarene HCꢀ
/
2.3.8. [tBuNCAuCꢀ
/
C(mphen)Cꢀ
/
CAuCNtBu] (8)
C(Ar)Cꢀ
/
CH (Arꢀmphen, 120 mg, 0.95 mmol; mes,
/
NEt3 (5 ml) was added to a solution containing
[AuCl(CNtBu)] (300 mg, 0.95 mmol) and 1,3-diethynyl-
benzene (60.5 mg, 0.48 mmol) in dichloromethane (15
ml). The suspension was stirred for 24 h and concen-
trated under vacuum to dryness. The solid residue was
dissolved in dichloromethane (2 ml) and diethyl ether
(20 ml) was added to precipitate a solid that was filtered,
227 mg, 1.35 mmol; dur, 105 mg, 0.58 mmol) and two
equivalents of [AuCl(SMe2)] (1) or [AuCl(tht)] (2, 3,
thtꢀtetrahydrothiophene) in degassed dichloro-
/
methane (15 ml) caused immediate precipitation of a
yellow (1, 2) or orange (3) solid. The suspension was
stirred for 10 min, filtered, washed with dichloro-
methane (3ꢃ
dried to give complexes 1ꢁ
Analyses (see Section 3). IR (cmꢄ1): n(Cꢀ
m.p. 162 8C (dec.). Analyses (see Section 3). IR (cmꢄ1):
n(CꢀC), 2104. 3: m.p. 154 8C (dec.). Analyses (see
Section 3). IR (cmꢄ1): n(Cꢀ
C), 2015.
/
10 ml) and diethyl ether (5 ml) and air-
3. 1: m.p. 150 8C (dec.).
C), 2108. 2:
washed with water (2ꢃ5 ml), dissolved in dichloro-
/
/
methane (20 ml) and filtered through MgSO4. The
solution was concentrated under vacuum (1 ml) and
diethyl ether (20 ml) was added to precipitate 8 as a pale
yellow solid. Yield 57%. M.p. 209 8C (dec.). Anal. Calc.
for C20H22Au2N2: C, 35.10; H, 3.24; N, 4.09. Found: C,
/
/
/
34.94; H, 3.03; N, 4.03%. IR (cmꢄ1): n(Cꢀ
/
N), 2226;
C), 2109. H NMR (200 MHz): d 1.57 (s, 18H,
1
2.3.7. Synthesis of [LAuCꢀ
mes, Lꢀt
BuNC (4), XyNC (Xyꢀ
Arꢀdur, Lꢀ
/
C(Ar)Cꢀ
C4H3Me2-2,6) (5);
PPh3 (6), BuNC (7)]
/
CAuL] [Arꢀ
/
n(Cꢀ
/
3
/
/
tBu), 7.10 [t, 1H, H5 (mphen), JHH
ꢀ8 Hz], 7.29 [dd,
/
t
3
H6 (mphen), JHH
4
8 Hz, JHH
/
/
2H, H4ꢂ
/
ꢀ
ꢀ
/
ꢀ
/
1.5 Hz],
4
To a suspension containing ca. 0.2 mmol of 2 (for 4,
5) or 3 (for 6, 7) in degassed dichloromethane (20 ml) 4
equiv. of the appropriate ligand were added. After 1 h of
stirring the reaction mixture was filtered through Celite.
The solution was concentrated (2 ml) and diethyl ether
(20 ml) was added to precipitate a yellow (4, 5) or pale
yellow (6) or white (7) solid that was filtered under
vacuum and air-dried. 4: yield 75%. M.p. 170 8C (dec.).
Anal. Calc. for C23H28Au2N2: C, 38.03; H, 3.89; N, 3.86.
7.54 [t, 1H, H2 (mphen), JHH
/
1.5 Hz] ppm. 13C{1H}
NMR (75.4 MHz): d 29.77 (s, Me), 58.52 (s, CMe3),
102.93 (s, CCAu), 121.83 (s, CAu), 124.43 [s, C1
(mphen)], 127.55 [s, C5 (mphen)], 131.13 [s, C4ꢂ
/
C6
(mphen)]; 136.21 [s, C2 (mphen)] ppm.
2.3.9. Synthesis of [Ph3PAuCꢀ
/
C(Ar)Cꢀ
/
CAuPPh3]
[Arꢀmphen (9) mes (10)]
/
To a solution of the appropriate diethynylarene (9:
35.4 mg, 0.21 mmol; 10: 153 mg, 0.91 mmol) in degassed
dichloromethane (30 ml) was added [Au(acac)PPh3] (9:
234.5 mg, 0.42 mmol; 10: 1117 mg, 2 mmol) and the
reaction mixture was stirred for 1.5 h (9) or 7 h (10)
under a nitrogen atmosphere. The resulting solution was
filtered through Celite, concentrated under vacuum (9: 2
ml; 10: 5 ml) and diethyl ether (9: 40 ml; 10: 70 ml) was
added to precipitate a white (9: 172 mg, 0.17 mmol) or
bright yellow (10: 593 mg, 0.456 mmol) solid, which was
filtered and dried in a nitrogen atmosphere. 9: yield 79%.
M.p. 151 8C. Anal. Calc. for C46H34Au2P2: C, 52.97; H
Found: C, 38.20; H, 3.70; N, 4.09%. IR (cmꢄ1): n(Cꢀ
/
1
t
N), 2220. H NMR (200 MHz): d 1.55 (s, 18H, Bu),
2.44 (s, 6H, Me), 2.72 (s, 3H, Me), 6.83 [s, 1H, Ar (Mes)]
ppm. 13C{1H} NMR (50.3 MHz): d 20.4 (Me), 21.4
(Me), 29.6(Cꢁ
/
Me3), 58.2(C ꢁ
/
Me3), 100.5(C ꢁ
/
CAu),
121.6(C ꢁAu), 127.0, 129.4, 138.6, 142.7, 147.0 (CN)
/
ppm. 5: yield 74%. M.p. 200 8C (dec.). Anal. Calc. for
C31H28Au2N2: C, 45.27; H, 3.43; N, 3.41. Found: C,
45.60; H, 3.39; N, 3.37%. IR (cmꢄ1): n(Cꢀ
/
N), 2204(s).
1H NMR (200 MHz): d 2.44 (s, 12H, Me), 2.48 (s, 6H,
Me), 2.78 (s, 3H, Me), 6.87 [s, 1H, (mes)], 7.14ꢁ7.36 (m,
/
6H, Xy) ppm. 13C{1H} NMR (50.3 MHz): d 18.7 (Me),
21.6 (Me), 121.8, 128.4, 130.7, 136.2, 139.1 ppm. 6: yield
75%. M.p. 115 8C (dec.). Anal. Calc. for C50H42Au2P2:
3.29. Found: C, 52.74; H, 3.13%. IR (cmꢄ1): n(Cꢀ
/
C),
1
2099. H NMR (200 MHz): d 7.13 [t, 1H, H5 (mphen),
3
3JHH
Hz, 4JHH
H2 (mphen), JHH
MHz):
(mphen)], 127.58 [s, C5 (mphen)], 129.09 (d, m-C,
ꢀ
/
8 Hz], 7.37 [dd, 2H, H4ꢂ
/
H6 (mphen), JHH
ꢀ8
/
1
C, 54.66; H, 3.85. Found: C, 54.24; H, 4.05. H NMR
ꢀ
/
2 Hz], 7.41ꢁ
/
7.59 (m, 30H, PPh3), 7.65 [t, 1H,
2 Hz] ppm. 13C{1H} NMR (50.3
4
(200 MHz): d 2.53 (s, 12H, Me). 7.42ꢁ
/
7.60 (m, 30H,
PPh3) ppm. 13C{1H} NMR (50.3 MHz): d19.08 (Me),
ꢀ
/
d
104.10 (s, C ꢀ
/
CAu), 124.61[s, C1ꢂ
/
C3
3
129.06 (d, m-C, PPh3, JCP
ꢀ11 Hz), 130.02 (d, i-C,
/
4
55 Hz), 131.4 (d, p-C, PPh3, JCP
3
PPh3, JCP
134.4 (d, o-C, PPh3, JCP
ꢀ
/
ꢀ/3 Hz),
PPh3, JCP
ꢀ
/
11.4 Hz), 130.35 (d, i-C, PPh3, JCP 58
C6 (mphen)], 131.47 (d, p-C, PPh3,
ꢀ
/
2
ꢀ
/
12 Hz), 135.4 (CMe), ppm.
Hz), 131.12 [s, C4ꢂ
/
31P{1H} NMR (121 MHz) d 42.94 (s, PPh3) ppm. 7:
Yield 80%. M.p. 172 8C. Anal. Calc. for C24H30Au2N2:
C, 38.93; H, 4.08; N, 3.78. Found: C, 39.54; H, 4.26; N,
4JCP
2JCP
ꢀ
/
2.3 Hz); 131.95 (s, CAu); 134.31 (d, o-C, PPh3,
13.9 Hz); 135.81 (s, C2) ppm. 31P{1H} NMR
ꢀ
/
(121 MHz): d 42.51 (s, PPh3) ppm. Crystals of 9 suitable
for an X ray diffraction study were grown by the liquid
diffusion method using dichloromethane and diethyl
ether. 10: yield 60%. M.p. 220 8C (dec.). Anal. Calc. for
C49H40Au2P2: C, 54.26; H, 3.72. Found: C, 53.42; H,
3.79%. IR (cmꢄ1): n(Cꢀ
/
N), 2222; n(Cꢀ
/
C), 2018. 1H
t
NMR (200 MHz): d 1.55 (s, 18H, Bu), 2.45 (s, 12H,
C6Me4) ppm. 13C{1H} NMR (50.3 MHz): d 18.79 (Me),
29.75 (Cꢁ
123.48 (C ꢁ
147.81 (C ꢁN) ppm.
/
Me3), 58.39 (C ꢁ
/
Me3), 101.99 (C ꢁ
/
CAu),
Me),
1
/
Au), 130.83 (C ꢁ
/
CꢀC), 135.41 (C ꢁ
/
/
3.74. H NMR (200 MHz): d 2.50 (s, 6H, Me), 2.84 (s,
/
3H, Me), 6.86 (s, 1H, mes), 7.43ꢁ7.61 (m, 30H, PPh3)
/

J. Vicente et al. / Inorganica Chimica Acta 347 (2003) 67ꢁ
/74
71
ppm. 13C{1H} NMR (50.3 MHz): d 21.0 (Me), 21.8
(Me), 101.5 (C ꢀCAu), 122.0, 127.2, 129.1(d, mꢁC,
11 Hz), 130.0 (d, i-C, PPh3, JCP 55
1 Hz), 134.3 (d, o-C,
14 Hz), 138.6, 142.8 ppm. 31P{1H} NMR
/
/
3
PPh3, JCP
ꢀ
/
ꢀ
/
4
Hz), 131.4 (d, p-C, PPh3, JCP
ꢀ
/
2
PPh3, JCP
ꢀ
/
(121 MHz): d 43.0 (s, PPh3) ppm. Crystals of 10 suitable
for an X ray diffraction study were grown as for 9.
2.3.10. [(tBuNH)(Et2N)CAuCꢀ
(NHtBu)(NEt2)] (11)
/
C(mes)Cꢀ/CAuC-
Diethylamine (2.5 ml, 24 mmol) was added to a
solution of complex 4 (276 mg, 0.38 mmol) in degassed
dichloromethane (10 ml), the resulting solution was
stirred for 2.5 h, concentrated under vacuum to dryness
and the residue stirred with n-pentane (20 ml) to give 11
as a white solid. Yield: 72%. M.p. 90 8C. Anal. Calc. for
C31H50Au2N4: C, 42.67; H, 5.77; N, 6.42. Found: C,
42.23; H, 6.06; N, 6.62%. IR (cmꢄ1): n(NH), 3332; n(Cꢀ
/
C), 2102. 1H NMR (200 MHz): d 1.13 [t, 6H, Me
(NEt2)], 1.29 [t, 6H, Me (NEt2)], 1.65 (s, 18H, tBu), 2.46
[s, 6H, Me (mes)], 2.78 [s, 3H, Me (mes)], 3.24 (q, 4H,
CH2), 4.05 (q, 4H, CH2), 5.83 (s, 2H, NH), 6.79 (s, 1H,
mes) ppm. 13C{1H} NMR (50.3 MHz): d 12.3, 14.4,
21.4, 22.2, 32.1, 40.3, 54.4, 54.6, 103.7, 123.3, 127.2,
133.9, 138.0, 142.5, 206.8 ppm.
Scheme 1.
sulfur in the elemental analysis of 1 allowed us to
estimate the approximate NEt3/1 ratio to be about 0.3/1.
The reactions of these polymers to give the well-
characterized monomers 4ꢁ
nature. This method has been used previously for the
synthesis of complexes homologous to 1ꢁ3 with Arꢀ
4,4?-C6H4C6H4, 4-(C6H2Me2,2,5) [2].
For the synthesis of neutral dinuclear complexes of
the type [LAuCꢀC(Ar)CꢀCAuL] we have used up to
four different synthetic methods (see bꢁe in Scheme 1).
/7 support their proposed
/
/
3. Results and discussion
/
/
/
3.1. Synthesis
Upon reaction of the polymeric complexes 1 and 2 with
two equivalents of phosphine or isocyanide ligands (L),
The reactions in dichloromethane between various
complexes
Lꢀt
[LAuCꢀ
/
C(Ar)Cꢀ
/
CAuL]
[Arꢀ
/
mes,
diethynylarenes HCꢀ
[AuClL] [Lꢀdimethylsulfide (dms), tetrahydrothio-
phene (tht)] in the presence of an excess of triethylamine
(method a) produce the insoluble complexes [AuCꢀ
C(Ar)CꢀCAu]n, [Arꢀ1,3-C6H4 (mphen) (1), 1,3-
(C6HMe3-2,4,6) (mes) (2), 1,4-(C6Me4-2,3,5,6) (dur)
(3)] (see Chart 1 and Scheme 1). The by-product
(NHEt3)Cl can be readily separated by exploiting its
solubility in dichloromethane. To account for both the
insolubility and the small sulfur and nitrogen content
shown by the elemental analyses of these complexes [1:
/
C(Ar)Cꢀ
/
CH and complexes
/
BuNC (4), XyNC (5); Arꢀ
/
dur, Lꢀ
/PPh3 (6),
/
tBuNC (7)] form in good yields (method b) although
this method had been found inconvenient for the
synthesis of other alkynylgold(I) phosphine derivatives
/
/
/
[18]. Complexes 4ꢁ
the labile ligands (NEt3 and dms or tht) and the p(Cꢀ
C)0Au interactions in 2 or 3 by the strong donor L
ligands. We have prepared the homologous complex
[tBuNCAuCꢀ CAuCNtBu] (8) through a
C(mphen)Cꢀ
/7 result from the replacement of both
/
/
/
/
different method involving the reaction of two equiva-
lents of [AuCl(CNtBu)] with the corresponding diethy-
nylarene in the presence of NEt3 (method c). Complexes
of the same type, namely [Ph3PAuCꢀ
CAuPPh3] [Arꢀmphen (9), mes (10)], can be obtained
by reacting the appropriate diethynylarene with two
equivalents of [Au(acac)PPh3] (method d). We have
previously shown that acetylacetonatogold(I) complexes
deprotonate organic substrates containing weakly acidic
hydrogen atoms to give a variety of gold(I) complexes
Anal. Calc. for C10H4Au2×
/
0.3NEt3: C, 25.84; H, 1.56;
N, 0.76. Found: C, 27.42; H, 1.42; N, 0.60%. 2: Anal.
Calc. for C13H10Au2: C, 27.88; H, 1.80. Found: C, 30.97;
H, 2.78; N, 0.88; S, 0.71%. 3: Anal. Calc. for C14H12Au2:
C, 29.29; H, 2.11. Found: C, 27.02; H, 2.28; N, 0.20; S,
0.96%] we assume that the bidentate dialkynyl ligand,
resulting from the deprotonation of the corresponding
dialkyne by the base NEt3, replaces both the chloro and
the labile sulfur donor ligand to give an open chain
polymeric species in which some gold atoms complete
their coordination spheres by side-on coordination to
/
C(Ar)Cꢀ
/
/
[19ꢁ
/
37] including alkynyl derivatives [38ꢁ40]. The
/
extension of this method to the preparation of com-
plexes 9 and 10 provides further examples of the
synthetic utility of the ‘acac method’ [41].
one Cꢀ
/
C bond while others coordinate triethylamine or
the corresponding sulfur donor ligand. The absence of

72
J. Vicente et al. / Inorganica Chimica Acta 347 (2003) 67ꢁ74
/
The carbene complex [(tBuNH)(Et2N)CAuCꢀ
C(mes)Cꢀ
CAuC(NHtBu)(NEt2)] (11) was obtained by
reacting the corresponding isocyanide complex (4) with
diethylamine (method e). It is well documented that
alcohols and primary and secondary amines add to
isocyanidegold(I) complexes to give the corresponding
/
five-position and the inequivalent methyl groups in the
2- and 4ꢂ6-positions, respectively. In complexes 6 and 7
one singlet is observed for all equivalent Me groups in
the alkynyl ligand. The spectra show also the resonances
due to the neutral ligands. Thus, the presence of PPh3 in
/
/
6, 9 and 10 is evidenced by a multiplet (7.4ꢁ7.6 ppm) in
/
1
carbene derivatives [40,42ꢁ
/46].
their H NMR spectra and a singlet resonance in their
31P{1H} NMR spectra at around 40 ppm, as found for
other alkynylphosphinegold(I) complexes [39,46]. The
isocyanide ligand present in 4, 7 and 8 (tBuNC) or 5
(XyNC) is responsible for a methyl resonance around
1.6 ppm (tBu) or 2.44 (Xy). In addition, 5 shows a
3.2. Structure of complexes
3.2.1. Crystal structures of 9 and 10
Figs. 1 and 2 show the crystal structures of complexes
9 and 10, respectively. The crystal data are collected in
Table 1. Complexes 9 and 10 are isostructural. In both
cases one of the gold atoms is in an essentially linear
environment [CAuP: 176.95(14)8 (9), 177.19(8)8 (10)]
while the other CAuP bond angle is appreciably bent
multiplet (7.14ꢁ
/
7.36 ppm) for the aromatic isocyanide
protons. The partial double bond character of the Cꢁ
/N
bonds in carbene complexes gives rise to the possible
existence of isomers Z and E [55]. The 1H NMR
spectrum of the carbene complex 11 show one single
resonance for the NH and tBu protons but two sets from
the ethyl protons. This could be attributed to the
formation of only one of the isomers and to the rapid
interchange of positions between the proton and the
tert-butyl group, the latter suggesting a weak p con-
[170.07(11)8 (9), 171.22(8)8 (10)]. The Auꢁ
CꢀC bond distances are in the ranges 1.998(5)ꢁ
2.2703(7)ꢁ
and are similar to those found in other alkynylgold(I)
complexes [1,10,40,46ꢁ
54] No short Auꢀ ꢀ ꢀAu contacts
were observed.
/
C, AuP and
2.046(4),
1.215(4) A, respectively,
/
/
˚
/
2.2821 and 1.204(4)ꢁ
/
/
tribution to the Nꢁ
C(H)tBu bond. The same NMR
/
pattern has been found in other carbene complexes by us
[46] and others [55].
3.2.2. NMR spectroscopy
The insolubility of the polymeric complexes 1ꢁ
The assignment of the 13C{1H} resonances was made
by comparison with those in the free dialkynes [56]. The
carbon nuclei of the alkynyl moieties appear in the
/3 in
most common organic solvents prevented the measure-
ment of their NMR spectra. We attribute to the limited
solubility of 5 the fact that some of the expected
resonances are absent in its 13C NMR spectrum even
after one night of data acquisition. The spectra of
complexes containing the same dialkynyl fragment dis-
play the same pattern for the diethynylarene protons
(see Section 2). Thus, complexes 8 and 9 display triplet
resonances for the protons in two- and five-positions
(see Chart 1) and a doublet of doublets for those in four-
ranges 121ꢁ
/
132 (C ꢁ
/
Au) and 98ꢁ
/
128 (C ꢀ
/
Cꢁ
/
Au) ppm,
downfield shifted with respect to those in the corre-
sponding alkynes, as observed for other alkynylgold
complexes [46]. The 13C NMR spectrum of the carbene
complex 11 displays, as the corresponding 1H NMR
spectrum, two sets of resonances for the ethyl carbon
nuclei.
1
and six-positions. In the H NMR spectra of complexes
4, 5, 10 and 11, the three singlet resonances observed
with intensities 1:3:6 correspond to the proton in the
3.2.3. IR spectroscopy
With the exception of 4ꢁ
show a weak n(CꢀC) band (see Section 2) slightly
/7 and 10, these complexes
/
˚
Fig. 1. Thermal ellipsoid plot (50% probability level) of 9. Selected bond lengths (A) and angles (8): Au(1)ꢁ
Au(2)ꢁC(10) 1.998(5), Au(2)ꢁP(2) 2.2725(12), C(7)ꢁC(8) 1.210(6), C(9)ꢁC(10) 1.209(7), C(8)ꢁAu(1)ꢁ
176.95(14), C(8)ꢁC(7)ꢁC(1) 175.7(4), C(7)ꢁC(8)ꢁAu(1) 170.2(4), C(10)ꢁC(9)ꢁC(3) 176.7(5), C(9)ꢁC(10)ꢁAu(2) 176.1(4).
/
C(8) 2.001(4), Au(1)ꢁ
/
P(1) 2.2750(11),
/
/
/
/
/
/
P(1) 170.07(11), C(10)ꢁ
/
Au(2)ꢁP(2)
/
/
/
/
/
/
/
/
/

J. Vicente et al. / Inorganica Chimica Acta 347 (2003) 67ꢁ
/74
73
˚
Fig. 2. Thermal ellipsoid plot (50% probability level) of 10. Selected bond lengths (A) and angles (8): Au(1)ꢁ
Au(2)ꢁC(11) 2.003(3), Au(2)ꢁP(2) 2.2703(7), C(7)ꢁC(8) 1.215(4), C(10)ꢁC(11) 1.204(4), C(8)ꢁAu(1)ꢁP(1) 171.22(8), C(11)ꢁ
C(8)ꢁC(7)ꢁC(1) 175.0(3), C(7)ꢁC(8)ꢁAu(1) 171.2(2), C(11)ꢁC(10)ꢁC(3) 178.6(3), C(10)ꢁC(11)ꢁAu(2) 177.5(3).
/
C(8) 2.006(3), Au(1)ꢁ
/
P(1) 2.2821(7),
/
/
/
/
/
/
/
Au(2)ꢁP(2) 177.19(8),
/
/
/
/
/
/
/
/
/
[4] C.P. McArdle, M.J. Irving, M.C. Jennings, J.J. Vittal, R.J.
Puddephatt, Chem. Eur. J. 8 (2002) 723.
shifted to lower energy with respect to the correspond-
ing band in the free alkynes HCꢀ
/
C(Ar)Cꢀ
/
CH [Arꢀ
/
[5] M.J. Irwin, L.M. Rendina, J.J. Vittal, R.J. Puddephatt, Chem.
Commun. (1996) 1281.
mphen, 2120; mes, 2102; dur, 2100 cmꢄ1]. Bands due to
the neutral ligands are also observed in the spectra of
complexes with PPh3 (at around 1100, 750, 700, 540 and
[6] I.R. Whittall, M.G. Humphrey, S. Houbrechts, J. Maes, A.
Persoons, S. Schmid, D.C.R. Hockless, J. Organomet. Chem. 544
(1997) 277.
500 cmꢄ1), isocyanide [n(Cꢀ
cmꢄ1] or carbene [n(NꢁH) at around 3300 cmꢄ1].
/
N) in the range 2204ꢁ2226
/
[7] M.J. Irwin, J.J. Vittal, R.J. Puddephatt, Organometallics 16
(1997) 3541.
/
[8] H. Xiao, K.K. Cheung, C.M. Che, J. Chem. Soc., Dalton Trans.
(1996) 3699.
[9] B.C. Tzeng, W.C. Lo, C.M. Che, S.M. Peng, Chem. Commun.
(1996) 181.
4. Supplementary material
[10] D. Li, X. Hong, C.M. Che, W.C. Lo, S.M. Peng, J. Chem. Soc.,
Dalton Trans. (1993) 2929.
Crystallographic data (excluding structure factors) for
the structural analysis have been deposited with the
Cambridge Crystallographic Data Centre, CCDC Nos.
178874 and 178875 for compounds 9 and 10, respec-
tively. Copies of this information may be obtained free
of charge from The Director, CCDC, 12 Union Road,
[11] C.M. Che, H.K. Yip, W.C. Lo, S.M. Peng, Polyhedron 13 (1994)
887.
[12] C.M. Che, H.Y. Chao, V.M. Miskowski, Y.Q. Li, K.K. Cheung,
J. Am. Chem. Soc. 123 (2001) 4985.
[13] R.J. Puddephatt, Coord. Chem. Rev. 216 (2001) 313.
[14] W.-Y. Wong, K.-H. Choi, G.-L. Lu, J.-S. Shi, P.-Y. Lai, S.-M.
Chan, Z. Lin, Organometallics 20 (2001) 5446.
[15] J. Vicente, J.A. Abad, J. Gil-Rubio, P.G. Jones, Organometallics
14 (1995) 2677.
Cambridge, CB2 1EZ, UK (fax: ꢂ44-1223-336-033; e-
/
mail: deposit@ccdc.cam.ac.uk or www: http://
www.ccdc.cam.ac.uk).
[16] X.X. Neenan, G.M. Whitesides, J. Org. Chem. 53 (1988) 2489.
[17] P. Kazmierczak, L. Skulski, Synthesis (1998) 1721.
[18] R.J. Cross, M.F. Davidson, J. Chem. Soc., Dalton Trans. (1986)
411.
Acknowledgements
[19] J. Vicente, M.T. Chicote, J.A. Cayuelas, J. Fernandez-Baeza, P.G.
Jones, G.M. Sheldrick, P. Espinet, J. Chem. Soc., Dalton Trans.
(1985) 1163.
We thank DGES (PB97-1047) and the Fonds der
Chemischen Industrie for financial support. M.M.A.-F.
thanks Fundacio´n Se´neca (Comunidad Auto´noma de la
Regio´n de Murcia, Spain) for a grant.
[20] J. Vicente, M.T. Chicote, I. Saura-Llamas, J. Turpin, J. Fernan-
dez-Baeza, J. Organomet. Chem. 333 (1987) 129.
[21] J. Vicente, M.T. Chicote, I. Saura-Llamas, P.G. Jones, K. Meyer-
Base, C.F. Erdbrugger, Organometallics 7 (1988) 997.
¨
¨
[22] J. Vicente, M.T. Chicote, M.C. Lagunas, P.G. Jones, J. Chem.
Soc., Dalton Trans. (1991) 2579.
References
[23] J. Vicente, M.T. Chicote, M.C. Lagunas, P.G. Jones, J. Chem.
Soc., Chem. Commun. (1991) 1730.
[24] J. Vicente, M.T. Chicote, P.G. Jones, Inorg. Chem. 32 (1993)
4960.
[1] G.C. Jia, R.J. Puddephatt, J.D. Scott, J.J. Vittal, Organometallics
12 (1993) 3565.
[25] J. Vicente, M.T. Chicote, M.C. Lagunas, Inorg. Chem. 32 (1993)
3748.
[2] M.J. Irwin, G.C. Jia, N.C. Payne, R.J. Puddephatt, Organome-
tallics 15 (1996) 51.
[26] J. Vicente, M.T. Chicote, P. Gonza´lez-Herrero, P.G. Jones, J.
Chem. Soc., Dalton Trans. (1994) 3183.
[3] M.-A. MacDonald, R.J. Puddephatt, Organometallics 19 (2000)
4970.

74
J. Vicente et al. / Inorganica Chimica Acta 347 (2003) 67ꢁ74
/
[27] J. Vicente, M.T. Chicote, P. Gonza´lez-Herrero, P.G. Jones, B.
Ahrens, Angew. Chem., Int. Ed. Engl. 33 (1994) 1852.
[28] J. Vicente, M.T. Chicote, R. Guerrero, P.G. Jones, J. Chem. Soc.,
Dalton Trans. (1995) 1251.
[41] J. Vicente, M.T. Chicote, Coord. Chem. Rev. 193ꢁ
/
195 (1999)
1143.
[42] J.E. Parks, A.L. Balch, J. Organomet. Chem. 71 (1974) 453.
[43] F. Bonatti, G. Minghetti, J. Organomet. Chem. 59 (1973) 403.
[44] G. Minghetti, L. Baratto, F. Bonatti, J. Organomet. Chem. 102
(1975) 397.
[29] J. Vicente, M.T. Chicote, R. Guerrero, P.G. Jones, J. Am. Chem.
Soc. 118 (1996) 699.
[30] J. Vicente, M.T. Chicote, C. Rubio, Chem. Ber. 129 (1996) 327.
[31] J. Vicente, M.T. Chicote, M.D. Abrisqueta, P. Gonza´lez-Herrero,
R. Guerrero, Gold Bull. 31 (1998) 83.
[45] J.A. McCleverty, M.M.M. Da Mota, J. Chem. Soc., Dalton
Trans. (1973) 2571.
[46] J. Vicente, M.T. Chicote, M.D. Abrisqueta, P.G. Jones, Organo-
metallics 16 (1997) 5628.
[32] J. Vicente, M.T. Chicote, M.D. Abrisqueta, P. Gonza´lez-Herrero,
R. Guerrero, Gold Bull. 31 (1998) 126.
[47] N.C. Payne, R. Ramachandran, R.J. Puddephatt, Can. J. Chem.
73 (1995) 6.
[33] J. Vicente, M.T. Chicote, M.C. Lagunas, Helv. Chim. Acta 82
(1999) 1202.
[48] I.R. Whittall, M.G. Humphrey, S. Houbrechts, A. Persoons,
D.C.R. Hockless, Organometallics 15 (1996) 5738.
[49] T.E. Muller, S.W.-K. Choi, D.M.P. Mingos, D. Murphy,
D.J.D.J. Williams, J. Organomet. Chem. 484 (1994) 209.
[50] S.J. Shieh, X. Hong, S.M. Peng, C.M. Che, J. Chem. Soc., Dalton
Trans. (1994) 3067.
[34] J. Vicente, M.T. Chicote, I. Saura-Llamas, M.C. Lagunas, M.C.
Ram´ırez de Arellano, P. Gonza´lez-Herrero, M.D. Abrisqueta, R.
Guerrero, in: P. Braunstein, L.A. Oro, P.R. Raithby (Eds.), Metal
Clusters in Chemistry, vol. 1, Wiley-VCH, Weinheim, 1999, pp.
493ꢁ508.
/
[35] J. Vicente, M.T. Chicote, P. Gonza´lez-Herrero, P.G. Jones, M.G.
Humphrey, M.P. Cifuentes, M. Samoc, B. Luther-Davies, Inorg.
Chem. 38 (1999) 5018.
[51] G.A. Carriedo, V. Riera, X. Solans, J. Solans, Acta Crystallogr.,
C. 44 (1988) 978.
[52] M.I. Bruce, E. Horn, J.G. Matisons, M.R. Snow, Aust. J. Chem.
37 (1984) 1163.
[36] J. Vicente, M.T. Chicote, Coord. Chem. Rev. 193ꢁ
/
195 (1999)
1143.
[53] M.I. Bruce, D.N. Duffy, Aust. J. Chem. 39 (1986) 1697.
[54] M.I. Bruce, K.R. Grundy, M.J. Liddell, M.R. Snow, E.R.T.
Tieknik, J. Organomet. Chem. 344 (1988) C49.
[55] G. Banditelli, F. Bonati, S. Calogero, G. Valle, J. Organomet.
Chem. 275 (1984) 153.
[37] J. Vicente, M.T. Chicote, R. Guerrero, I.M. Saura-Llamas, P.G.
Jones, M.C. Ram´ırez de Arellano, Chem. Eur. J. 7 (2001) 638.
[38] J. Vicente, M.T. Chicote, I. Saura-Llamas, M.C. Lagunas, J.
Chem. Soc., Chem. Commun. (1992) 915.
[39] J. Vicente, M.T. Chicote, M.D. Abrisqueta, J. Chem. Soc., Dalton
Trans. (1995) 497.
[56] E.C. Pretsch, T. Clerc, J. Seibl, W. Simon, Tablas para la
elucidacio´n estructural de compuestos orga´nicos por me´todos
espectrosco´picos, Editorial, Alhambra, Madrid, 1985, H225.
[40] J. Vicente, M.T. Chicote, M.D. Abrisqueta, P.G. Jones, M.G.
Humphrey, M.P. Cifuentes, M. Samoc, B. Luther-Davies, Orga-
nometallics 19 (2000) 2968.
[57] G.M. Sheldrick, SHELXL-97, University of Gottingen, Gottingen,
¨ ¨
Germany, 1997.