Allenylidene and derived alkynyl complexes of iron(II) with the {FeBr(Et2PCH2CH2PEt2) 2}+ centre

Article abstract of DOI:10.1016/S0022-328X(03)00766-6

The allenylidene complexes trans-[FeBr{=C=C=C(R)Ph}(depe)₂] [BPh₄] (depe=Et₂PCH₂CH₂ PEt₂; R=Me 1, Ph 2) were obtained by treatment of a methanolic solution of trans-[FeBr₂(depe)₂] with the appropriate alkynol HC≡C-C(R)Ph(OH), in the presence of Na[BPh₄]. The methylallenylidene ligand in 1 undergoes reversible deprotonation (by NaOMe) to yield the enynyl (or ene-yne) complex of iron(II), trans-[FeBr{-C≡C-C(= CH₂)Ph}(depe)₂] 3. The diphenylallenylidene ligand in 2 undergoes regioselective hydride γ-addition on reaction with K[B{CH(Me)Et}₃H] to afford the alkynyl complex trans-[FeBr {-C≡C-C(H)Ph₂}(depe)₂] 4.

Full text of DOI:10.1016/S0022-328X(03)00766-6

Journal of Organometallic Chemistry 684 (2003) 315Á321
/
www.elsevier.com/locate/jorganchem
Allenylidene and derived alkynyl complexes of iron(II) with the
{FeBr(Et2PCH2CH2PEt2)2}ꢀ centre
Ana I.F. Venaˆncio a, Lu´ısa M.D.R.S. Martins a,b, Armando J.L. Pombeiro a,*
a Centro de Qu´ımica Estrutural, Complexo I, Instituto Superior Te´cnico, Av. Rovisco Pais, 1049-001 Lisbon, Portugal
b Seccao de Qu´ımica Inorgaˆnica, DEQ, ISEL, R. Conselheiro Em´ıdio Navarro, 1949-014 Lisbon, Portugal
¸˜
Received 17 April 2003; received in revised form 11 June 2003; accepted 11 June 2003
Dedicated to Professor E.O. Fischer on the occasion of his 85th birthday
Abstract
The allenylidene complexes trans-[FeBr{Ä
obtained by treatment of a methanolic solution of trans-[FeBr2(depe)2] with the appropriate alkynol HCÅ
presence of Na[BPh4]. The methylallenylidene ligand in 1 undergoes reversible deprotonation (by NaOMe) to yield the enynyl (or
eneÁyne) complex of iron(II), trans-[FeBr{ÃCÅCÃC(ÄCH2)Ph}(depe)2] 3. The diphenylallenylidene ligand in 2 undergoes
CÅCÃ
/
CÄ
/
CÄ
/
C(R)Ph}(depe)2][BPh4] (depeꢁ
/
Et2PCH2CH2PEt2; Rꢁ
/
Me 1, Ph 2) were
/
CÃ
/
C(R)Ph(OH), in the
/
/
/
/
/
regioselective hydride g-addition on reaction with K[B{CH(Me)Et}3H] to afford the alkynyl complex trans-[FeBr{Ã
/
/
/
C(H)Ph2}(depe)2] 4.
# 2003 Elsevier B.V. All rights reserved.
Keywords: Iron; Alkynols; Allenylidenes; Alkynyls; Enynyls; Propargyl alcohols
1. Introduction
[21,24,36Á38], namely towards the formation of multiple
/
metal-carbon bonded species, we have initiated the
investigation of the coordination chemistry of alkynols
at an iron(II) phosphinic centre. Hence, the cyclic
The chemistry of allenylidene complexes, [M]Ä
/
CÄ
/
CÄ
/
CR2, is currently attracting great attention [1Á4], being
/
developed mainly after the Selegue [5] general synthetic
method based on the dehydration of propargylic alco-
allenylidene complex trans-[FeBr(Ä
pe)2][BPh4] (depeꢁ
Et2PCH2CH2PEt2) and the h2-al-
kyne complexes trans-[FeBr{h2-HCÅ
C(CH2)nOH}-
(depe)2][BPh4] (nꢁ1 or 2) were obtained on reaction
of trans-[FeBr2(depe)2], in the presence of Na[BPh4],
with the corresponding cyclic alkynol HCÅCC6H10OH
or linear primary alkynols HCÅC(CH2)nOH, respec-
tively (Scheme 1) [21]. The cyclic alkynol underwent
dehydration to afford the ligated allenylidene, but the
primary alkynols were stable towards dehydration
allowing the isolation of h2-alkyne complexes which
commonly are postulated as intermediates in the for-
mation of the allenylidene products.
/
CÄ
/
CÄ
/
C6H10)(de-
/
hols (alkynols), HCÅ
/
CÃ/CR2OH, by transition metal
/
centres. The interest of allenylidene complexes does not
arise only from the associated rich coordination chem-
istry, but also from their recognized significance in
material science [6,7], in synthesis (e.g. towards metal-
containing copolymers [3,8]) and in catalysis (e.g.
/
/
/
rutheniumÁ
sors for olefin metathesis [9Á
various reactions of propargylic alcohols [16Á
However, allenylidene complexes of iron are still
scarce [21Á28] and in pursuit of our interest on the
activation, by transition metal centres, of alkynes [29Á
35] and alkynols or derived alkenylcarbyne complexes
/
allenylidene complexes as catalyst precur-
15] or as catalysts for
20]).
/
/
/
/
In the work we now report we have extended the
investigation to (i) tertiary alkynols HCÅ
and to (ii) the study of the effect of the nature of the
organic R group (alkyl vs. aryl). Hence, both HCÅCÃ
C(R)Ph(OH) (RꢁMe; Ph) are shown to undergo
dehydration to yield the corresponding linear allenyli-
/
CÁ/C(R)PhOH
/
/
* Corresponding author. Tel.: ꢀ
4455.
E-mail address: pombeiro@ist.utl.pt (A.J.L. Pombeiro).
/
351-1-841-9237; fax: ꢀ351-21-846-
/
/
0022-328X/03/$ - see front matter # 2003 Elsevier B.V. All rights reserved.
doi:10.1016/S0022-328X(03)00766-6

316
A.I.F. Venaˆncio et al. / Journal of Organometallic Chemistry 684 (2003) 315Á
/321
Scheme 1.
dene complexes trans-[FeBr{Ä
which exhibit different further reactivities. In fact, the
methylallenylidene ligand, ÄCÄCÄC(Me)Ph, exhibits
acidic character to give the ligated ÃCÅCÃC(ÄCH2)Ph
which, to our knowledge, provides the first example of
an enynyl (or eneÁyne) complex of iron to be reported.
In contrast, the diarylallenylidene presents a g-electro-
/
CÄ
/
CÄ
/
C(R)Ph}(depe)2]ꢀ
The trans geometry of these complexes is assigned on
the basis of the singlet observed in their 31PÁ{1H}-NMR
/
/
/
/
spectra. In the 13CÁ
/
{1H}-NMR spectra the carbon
atoms from the cumulenic chain are observed at d
/
/
/
/
2
306.5 (1) and 305.5 (2) (qnt, JCP
ꢁ
/
36 Hz, assigned to
Ca), 235.1 (1) and 244.9 (2) (qnt, JCP 4 and 5 Hz, Cg
with the lowest JCP value, in comparison with those for
Ca and Cb) and 148.5 (1) and 149.4 (2) ppm (qnt, 3JCP
6 Hz, Cb). The allenylidene complexes [W(ÄCÄCÄ
CPh2)(CO)5] [39] (d 302.5 (Ca)ꢀd 155.5 (Cg)ꢀ
145.0 (Cb)) and [Mn(h5-C5H5)(Ä
CÄCÄCPh2)(CO)2]
d 139.8 (Cb)) also
4
/
ꢁ
/
philic behaviour to form the alkynyl group Ã
/
CÅ
/
CÃ
/
ꢁ
/
C(H)Ph2 upon reaction with an hydridic reagent.
/
/
/
/
/d
/
/
/
[40] (d 304.5 (Ca)ꢀ
/
d 223.3 (Cg)ꢀ
/
2. Results and discussion
display the same order of 13C chemical shifts within the
cumulenic carbon chain, although for most of the
allenylidene complexes the order Caꢀ
/
CbꢀCg has
/
2.1. Synthesis and characterization
been proposed [3] without given evidence.
All the other resonances of the allenylidene and depe
Treatment of
[FeBr2(depe)2], at 40 8C, in the presence of Na[BPh4],
with 2-phenyl-3-butyn-2-ol, HCÅCC(Me)Ph(OH) or
1,1-diphenyl-2-propyn-1-ol, HCÅCCPh2(OH), leads
to the formation of the allenylidene complexes
trans-[FeBr{ÄCÄCÄC(R)Ph}(depe)2][BPh4] (depeꢁ
Et2PCH2CH2PEt2; RꢁMe 1, Ph 2), respectively
(Scheme 2, reactions 1 and 2), isolated as dark violet
(1) or dark blue (2) solids, in ca. 80Á50% yields. The
a
MeOH solution of trans-
ligands have also been assigned (see Section 4) in the 1H-
,
13CÁ{1H}- and 13C-NMR spectra, including those of
/
/
ipso-, ortho-, meta- and para- atoms of the phenyl rings.
Further, the FABꢀMS spectra of the complexes
exhibit the molecular ion, [M]ꢀ, and the corresponding
fragments derived from the stepwise elimination of the
/
/
/
/
/
/
bromide, [Mꢂ
/
Br]ꢀ, allenylidene, [Mꢂ
/
CÄ
/
CÄ
/
CR2]ꢀ, or
depe, [Mꢂ
/
depe]ꢀ, ligands.
/
complexes, as well as all the others discussed below,
have been characterised by IR and multinuclear NMR
spectroscopies, FABꢀMS spectrometry and elemental
analysis.
2.2. Reactivity
The methylallenylidene complex 1 undergoes depro-
tonation by NaOMe which acts as a Bronsted base
¨
In the IR spectra, the characteristic asymmetric
stretching vibration n(CÄ
/
CÄ
/
C) of the allenylidene
towards the methyl group of the allenylidene ligand
ligand is observed as a strong intensity band at 1893
(1) or 1876 (2) cmꢂ1, in accord with the electronic
nature of the R groups. These values are comparable
with those known for related allenylidene iron species,
yielding (Scheme 2, reaction 3) trans-[FeBr{Ã
CH2)Ph}(depe)2] (3) that appears to be the first enynyl
(or eneÁyne) complex of iron to be reported. This
/
CÅ
/
CÃ
/
C(Ä
/
/
compound is also obtained upon reaction of 1 with the
hydridic reagent K-selectride, K[B{CH(Me)Et}3H]. In
such as [Fe(CO)2(Ä
cmꢂ1) [26] and [Fe(h5-C5H5)(Ä
(dppeꢁ
Ph2PCH2CH2PPh2) (1926 cmꢂ1) [27], and fall
in the range (1988Á
1870 cmꢂ1 [3]) commonly observed
for the allenylidene metal complexes.
/
CÄ
/
CÄ
/CPh2){P(OMe)3}2] (1868
/
CÄCÄ
/
/
CPh2)(dppe)]ꢀ
its IR spectrum, n(CÅ
2020 (strong) and 1552 (medium) cmꢂ1, respectively,
whereas in the 1H-NMR spectrum the Ä
CH2 resonances
occur as two doublets (2JHH ca. 2 Hz) at d ca. 5.4 and
/
C) and n(CÄ/C) appear as bands at
/
/
/

A.I.F. Venaˆncio et al. / Journal of Organometallic Chemistry 684 (2003) 315Á
/321
317
Scheme 2.
1
5.1. These features are comparable with those quoted
for the related complexes [Ru(h5-C5Me5){Ã
CÅCÃC(Ä
CH2)Ph}(dippe)] (a, dippeꢁiPr2PCH2CH2PiPr2) (d
5.3 and 5.0, each signal observed as a doublet with
2JHH ca. 2 Hz) [41] and [OsH(h5-C5H5){Ã
CÅCÃC(Ä
CH2)Ph}(PiPr3)2][PF6] (b, d 5.4 and 5.0 as singlets) [43].
In the 13CÁ{1H}-NMR spectrum, the resonances of
the ÃCÅCÃCÄCH2 moiety in 3 appear as a quintet
(2JCP
28 Hz, Ca) at d 135.7, a quintet (JCP 2 Hz, Cb
or Cg) at d 135.9, a multiplet (Cg or Cb) at d 122.9 and a
quintet (5JCP
2 Hz, ÄCH2) at d 111.0 which, in the
13C-NMR spectrum, splits into the expected triplet
(JCH CH2) and the
2JCP (Ca) values are comparable with those displayed by
complexes a (109.6 ppm, 21 Hz [41]) and b (117.3 ppm,
24 Hz [42]) which also present the other d values for the
enynyl group similar to those of 3 (with the exception of
the much higher field Ca resonance quoted [42] for the
Os(IV) complex b).
counterion, as proved by the IR, H- and 31PÁ
/
{1H}-
/
/
/
/
NMR spectra (they are identical for both compounds,
except the data that concern the counterions). Regen-
eration of the allenylidene complex [Ru(h5-C5H5)
/
ꢀ
ꢁ
/
/
/
/
/
{Ä
/
CÄ
/
CÄ
/
C(/
CÄCHCHÄCHN
Me)(CH3)}(PPh3)2][PF6]
by protonation of the respective enynyl [Ru(h5-C5H5)
ꢀ
ꢁ
/
/
{Ã
/
CÅ
/
CÃ
/
C(/
CÄCHCHÄCHN
Me)(Ä
/
CH2)}(PPh3)2] with
/
/
/
/
water has been reported by others [43]. The latter
complex and the related enynyl Ru(II) complex a
mentioned above were obtained by the same general
method we have used in the preparation of 3 (deproto-
nation of the methyl group of a methylallenylidene
complex), although by using LiBu [43] or KOBut [41],
respectively, as the base. The enynyl complex [OsH(h5-
ꢁ
/
ꢁ
/
ꢁ
/
/
ꢁ
/
158 Hz) of quintets. The d (Ä
/
C5H5){Ã
from the spontaneous conversion, in CHCl3, of the
hydrideÁ
hydroxyalkynyl compound [OsH(h5-C5H5){Ã
CÅCÃ
C(CH3)Ph(OH)}(Pi Pr3)2][PF6] which resulted
from treatment of [OsCl(h5-C5H5)(PiPr3)2] with HCÅ
/
CÅ
/
CÃ
/
C(Ä
/
CH2)Ph}(PiPr3)2][PF6] was derived
/
/
/
/
/
The trans geometry of complex 1 is assigned on the
basis of the singlet resonance at d 67.4 ppm rel. H3PO4,
CC(CH3)Ph(OH), in the presence of Tl[PF6] [42].
The diphenylallenylidene ligand in complex 2 under-
goes regioselective hydride addition to the Cg atom upon
treatment with K-selectride, leading to the formation of
observed in the 31PÁ{1H}-NMR spectrum, whereas by
/
FABꢀMS spectrometry its molecular ion was detected,
[M]ꢀ (m/zꢁ
675), as well as a fragmentation pattern
initiated by the stepwise elimination of the bromide
[Mꢂ 596), the alkynyl [Mꢂ(ÃCÅCÃC(Ä
Br]ꢀ (m/zꢁ
CH2)Ph)]ꢀ (m/zꢁ depe]ꢀ (m/
547) or the depe [Mꢂ
zꢁ469) ligands.
/
the neutral alkynyl complex trans-[FeBr{Ã
/
CÅ
/
CÃ
/
C(H)Ph2}(depe)2] (4) (Scheme 2, reaction 4). This
reaction contrasts with that occurring with the methy-
lallenylidene complex 1 which on treatment with the
hydridic reagent undergoes deprotonation to give 3.
/
/
/
/
/
/
/
/
/
/
The deprotonation of the methylallenylidene ligand in
complexes 1 to give the enynyl product 3 is reversible
since the latter undergoes protonation at the methyli-
dene carbon, by reaction with HBF4, in CH2Cl2, to
regenerate the methylallenylidene species, forming the
compound identical to 1 but with [BF4]ꢂ as the
Hence, the Bronsted acidity of 1 overcomes its con-
¨
ceivable electrophilic behaviour.
Complex 4 exhibits in the IR spectrum a medium
C) vibration at 2057 cmꢂ1, whereas the
intensity n(CÅ
/
presence of the proton at the acetylenic chain CÅ
/
CÃ
/

318
A.I.F. Venaˆncio et al. / Journal of Organometallic Chemistry 684 (2003) 315Á321
/
C(H)Ph2 is accounted for by the singlet resonance
observed at d 4.91 in the 1H-NMR spectrum. This
chemical shift is similar to those observed for the related
4. Experimental
4.1. General procedures
Ru(II) complexes trans-[RuCl{Ã
4.3 or 4.8 for LꢁPh2PCH2PPh2 [44] or dppe [45]). In
the 13CÁ{1H}-NMR spectrum of 4, the Ca, Cb and Cg
resonances of the alkynyl ligand appear at much higher
/
CÅ
/
CÃ
/
C(H)Ph2}L2] (d
/
All the manipulations and reactions were carried out
in the absence of air using standard inert-gas flow and
high-vacuum techniques. Solvents were purified and
dried by standard methods and freshly distilled under
dinitrogen. The complex trans-[FeBr2(depe)2] was pre-
pared by a published method [47,48] and the alkynols
were used as purchased from Aldrich. The IR spectra
/
2
fields, d 113.5 (qnt, JCP
ꢁ28 Hz), 118.2 (m) and 47.7
/
(m), respectively, compared with the allenylidene pre-
cursor 2. In the 13C-NMR spectrum, the Cg signal splits
into the expected doublet (JCH
These d values are comparable with those reported
for trans-[RuCl{ÃCÅCÃC(H)Ph2}L2]: d 103.1 (qnt,
2JCP
16 Hz, Ca), 109.0 (s, Cb) and 48.1 (s, Cg), for
Lꢁ 16 Hz, Ca),
Ph2PCH2PPh2 [44]; d 105.4 (qnt, 2JCP
111.4 (s, Cb) and 49.2 (s, Cg), for Lꢁdppe [45]. These
ꢁ
/
127 Hz).
(4000Á
400 cmꢂ1) were recorded on a Bio-Rad FTS
3000MX instrument in KBr pellets, and the NMR
/
/
/
/
spectra (run in CD2Cl2 unless stated otherwise) on a
Varian UNITY 300 spectrometer at room temperature
ꢁ
/
/
ꢁ
/
1
(r.t.). H, 13C, 13CÁ
/
{1H} and 31PÁ{1H} chemical shifts
(d) are reported in ppm relative to TMS and H3PO4,
/
/
Ru(II) complexes where also obtained from g-addition
of hydride to the respective allenylidene compounds
respectively. In the 13C-NMR data, assignments and
coupling constants common to the 13CÁ
/
{1H}-NMR
singlet;
quintet;
doublet of doublets;
doublet of multiplets;
triplet of quintets; tmꢁtriplet of multiplets;
qqntꢁquartet of quintets; mꢁmultiplet; bꢁbroad.
upon reaction with NaBH4. The alkynyl complex [Re{Ã
/
spectra are not repeated. Abbreviations: sꢁ
dꢁdoublet; tꢁtriplet; qꢁquartet; qntꢁ
dqꢁdoublet of quartet; ddꢁ
dtꢁdoublet of triplets; dmꢁ
tqntꢁ
/
CÅCÃC(H)Ph2}(CO)2(triphos)] (triphosꢁMeC(CH2-
/
/
/
/
/
/
/
PPh2)3) [46] was synthesised similarly by using LiHBEt3
as the hydride source. Our alkynyl complex 4 appears to
correspond to the first example of this type of reaction
at an iron(II) centre.
/
/
/
/
/
/
/
/
/
The FABꢀMS spectrum of complex 4 shows the
C, H and N elemental analyses were carried out by the
Microanalytical Service of the Instituto Superior Te´c-
nico. Positive-ion FAB mass spectra were obtained on a
Trio 2000 instrument by bombarding 3-nitrobenzyl
molecular ion, [M]ꢀ (m/zꢁ
/
738), which by loss of H,
C(H)Ph2 or depe leads to the corresponding
fragments with m/zꢁ737, 659, 547 and 532.
Br, Ã
/
CÅ
/
CÃ
/
/
alcohol matrices of the samples with 8 keV (ca. 1.28ꢃ
/
10ꢂ15 J) Xe atoms. Nominal molecular masses were
calculated using the isotopes 56Fe and 79Br. However,
further complexity due to addition (from matrix) or loss
of hydrogen was usually not taken into account. Mass
calibration for data system acquisition was achieved
using CsI.
3. Final comments
This work shows that a phosphinic iron(II) centre can
stabilize allenylidene ligands conveniently prepared
from tertiary alkynols to give stable [Fe]ꢀ Ä
/
CÄ
/
CÄ
/
CR2
4.2. Syntheses
complexes that are readily obtained from reactions of
the alkynols with trans-[FeBr2(depe)2] which presents
one labile bromide ligand. The p-electron releasing
ability of the binding trans-{FeBr(depe)2}ꢀ site has a
stabilizing role of the p-electron acceptor allenylidene
ligand whose reactivity is strongly dependent on the
nature (alkyl or aryl) of the organic R group. Although
4.2.1. Allenylidene complexes trans-[FeBr{Ä
/
CÄ
/
CÄ/C
(R)Ph}(depe)2][BPh4] (RꢁMe 1, Ph 2)
/
To a stirred solution of trans-[FeBr2(depe)2] (0.20 g,
0.318 mmol) in MeOH (50 cm3), under dinitrogen and at
r.t., was added an excess (molar ratio 2:1) of a
methanolic solution of the appropriate alkynol (0.636
mmol in 10 ml). The solution was stirred at 40 8C during
the diarylallenylidene [Fe]ꢀ Ä
/
CÄ
/
CÄ
/
CPh2 behaves as a
g-electrophile and undergoes regioselective addition of
ca. 3Á
pale green to violet or dark blue, in the reactions with
CCPh2(OH), respectively.
/4 h and along this time its colour changed, from
an anionic nucleophile (Hꢂ) to yield an alkynyl
derivative, [Fe]Ã
/
CÅ
/
CÃ
/
C(H)Ph2, the methylallenylidene
species [Fe]ꢀ Ä
acid. The latter reaction appears to be particularly
HCÅ
/
CC(Me)Ph(OH) or HCÅ
/
/
CÄ
/
CÄ
/
C(CH )Ph behaves as a Bronsted
¨
3
Addition of a MeOH solution (10 cm3) of Na[BPh4]
(0.120 g, 0.350 mmol) led to the precipitation of the
allenylidene complexes 1 or 2, respectively. These
compounds were separated by filtration, recrystallized
promising in providing an easy entry to enynyl species,
[Fe]Ã
/
CÅ
/
CÃ
/
C(Ä/CH2)Ph, with an extra (ene) functional
site (apart from the ynyl one) available for further
from CH2Cl2Á
/
Et2O and dried in vacuo. Yield: 79%
reactivity which deserves to be explored.
(0.25 g) 1, 81% (0.272 g) 2.

A.I.F. Venaˆncio et al. / Journal of Organometallic Chemistry 684 (2003) 315Á
/321
319
1
4
(1): Anal. Calc. for C54H76BBrFeP4: C, 64.7; H, 7.8.
Found: C, 64.5; H, 8.0%. IR (KBr, cmꢂ1): n(CÄ
CÄC)
7.8 Hz, 2H, Ho
7.5 Hz, 1H, Hp
CMe(C6H5)), 7.34 (m, 10H, Hm from CÄCÄ
CMe(C6H5) and Ho from BPh4ꢂ), 7.04 (t, Jꢁ
7.2 Hz,
8H, Hm from B(C6H5)4ꢂ), 6.89 (t, JHH
6.9 Hz, 4H, Hp
from BPh4ꢂ), 2.46 (dq, JHP
15.6, JHH
(CH2CH3)2), 1.50 (dq, JHP
ꢁ
/
15.2, JHH
ꢁ
/
7.6 Hz, 4H,
/
/
/
1
(CH3CH2)2PCH2CH2P(CH2CH3)2, 1.17 (m, 12H,
/
1
2
1893 (s). H-NMR: d 7.93 (d, JHH
from CÄCÄCMe(C6H5)), 7.76 (t, JHH
from CÄCÄ
ꢁ
ꢁ
/
1
(CH3CH2)2PCH2CH2P(CH2CH3)2), 1.02 (m, 12H,
(CH3CH2)2PCH2CH2P(CH2CH3)2). 31PÁ
/
2
/
/
/
/
{1H}-NMR:
/
/
/
/
d 54.1 ppm (s). 13CÁ
36 Hz, Ca), 244.9 (qnt, JCP
/
{1H}-NMR: d 305.5 (qnt, JCP
ꢁ
/
2
/
4
ꢁ5 Hz, Cg), 164.3 (q,
/
ꢁ
/
1JCB
Cb), 146.3 (qnt, JCP
(s, Cm from BPh4ꢂ), 130.5 (s, Cp from CÄ
129.7 (s, Co from CÄCÄCPh2), 128.0 (s, Cm from CÄ
CPh2), 125.8 (q, JCB
2 Hz, Co from BPh4ꢂ), 122.0 (s,
Cp from BPh4ꢂ), 22.5 (qnt, JCP 21(CH3-
6 Hz,
CH2)2PCH2CH2P(CH2CH3)2), 20.2 (qnt, JCP 11 Hz,
(CH3CH2)2PCH2CH2P(CH2CH3)2), 19.9 (qnt, JCP
Hz,
12(CH3CH2)2PCH2CH2P(CH2CH3)2), 9.9 (s,
ꢁ
/
49 Hz, Ci from BPh4ꢂ), 149.4 (qnt, JCP
4 Hz, Ci from CÄCÄCPh2), 136.2
CÄCPh2),
CÄ
ꢁ6 Hz,
/
3
1
ꢁ
/
ꢁ
/
7.8 Hz, 4H,
/
4
ꢁ
/
/
/
1
/
(CH3CH2)2PCH2CH2P(CH2CH3)2), 2.15 (m, 4H,
(CH3CH2)2PCH2CH2P(CH2CH3)2), 1.91 (m, 4H,
(CH3CH2)2PCH2CH2P(CH2CH3)2), 1.76 (dq, JHP
2
/
/
1
/
/
/
/
/
2
2
ꢁ
/
ꢁ
/
14(CH3CH2)2PCH2CH2P-
ꢁ
/
/
15.2, JHH
ꢁ/7.6 Hz, 4H,
/
1.59 (m, 11H,
12(CH3CH2)2PCH2-
/
ꢁ
/
(CH2CH3)2), 1.72Á
/
ꢁ
/
6
CH2P(CH2CH3)2 and CÄ
/
CÄ
/
C(CH3)Ph), 1.20 (m, 12H,
12(CH3CH2)2PCH2CH2P(CH2CH3)2), 1.12 (m, 12H,
1
/
/
1
2
2
/
/
(CH3CH2)2PCH2CH2P(CH2CH3)2). 31PÁ
d 55.3 ppm (s). 13CÁ
36 Hz, Ca), 235.1 (qnt, JCP
1JCB 49 Hz, Ci from BPh4ꢂ), 148.5 (qnt, JCP
Cb), 143.3 (qnt, JCP 3 Hz, Ci from (CÄCÄCMePh),
136.2 (s, Cm from BPh4ꢂ), 131.6 (s, Cp from CÄ
CÄ
CMePh), 130.1 (s, Co from CÄCÄCMePh), 126.8 (s,
Cm from CÄCÄCMePh), 125.8 (q, JCB
from BPh4ꢂ), 121.9 (s, Cp from BPh4ꢂ), 33.1 (qnt, JCP
3 Hz, CÄCÄC(CH3)Ph), 22.4 (qnt, JCP 6 Hz,
(CH3CH2)2PCH2CH2P(CH2CH3)2), 20.3 (qnt, JCP
11 Hz, (CH3CH2)2PCH2CH2P(CH2CH3)2), 19.9 (qnt,
JCP (CH3CH2)2PCH2CH2P(CH2CH3)2), 9.8 (s,
5 Hz, 12
12(CH3CH2)2PCH2CH2P(CH2CH3)2), 9.4 (s, 21(CH3-
CH2)2PCH2CH2P(CH2CH3)2). 13C-NMR:
306.5
/
{1H}-NMR:
(CH3CH2)2PCH2CH2P(CH2CH3)2), 9.3 (s,
CH2)2PCH2CH2P(CH2CH3)2). 13C-NMR:
/
12(CH3-
305.5
(qnt), 244.9 (qnt), 164.3 (q), 149.4 (m), 146.3 (m),
2
d
/
{1H}-NMR: d 306.5 (qnt, JCP
ꢁ
/
4
ꢁ4 Hz, Cg), 164.3 (q,
/
1
2
1
3
136.2 (dt, JCH
2
160, JCH
ꢁ
/
153, JCH
ꢁ
/
7 Hz), 130.5 (dt, JCH
2
163, JCH
ꢁ
/
ꢁ
/
ꢁ6 Hz,
/
1
7 Hz), 129.7 (dd, JCH
ꢁ
/
ꢁ
/
ꢁ7 Hz),
/
ꢁ
/
/
/
1
128.0 (dt, JCH
2
162, JCH
1
6 Hz), 125.8 (dm, JCH
ꢁ
/
ꢁ
/
ꢁ
/
/
/
1
2
154 Hz), 122.0 (dt, JCH
ꢁ
/
156, JCH
ꢁ
/
8 Hz), 22.5 (tm,
130 Hz), 20.2 (m), 19.9 (tm, JCH 130 Hz), 9.9
129 Hz). FABꢀMS
Br]ꢀ, 547 [Mꢂ
(ÄCÄCÄ
depe]ꢀ, 341 [Mꢂ
depeꢂ(ÄCÄCÄ
/
/
1JCH
ꢁ
/
ꢁ
/
1
2
/
/
ꢁ3 Hz, Co
/
1
1
(q, JCH
ꢁ
/
128 Hz), 9.3 (q, JCH
ꢁ
/
ꢁ
/
(m/z): 737 [M]ꢀ, 658 [Mꢂ
CPh2)]ꢀ, 531 [Mꢂ
CPh2)]ꢀ.
/
/
/
/
/
1
2
/
/
ꢁ
/
/
/
/
/
/
/
/
ꢁ
/
ꢁ
/
/
4.2.2. Alkynyl complex trans-[FeBr{Ã
Ph}(depe)2] (3)
To a solution containing the allenylidene compound
trans-[FeBr{ÄCÄCÄC(Me)Ph}(depe)2][BPh4] (0.20 g,
/
Cꢁ
/
CÃ
/
C(Ä
/CH2)
/
/
d
(qnt), 235.1 (qnt), 164.3 (q), 148.5 (m), 143.3 (m),
1
136.2 (dt, JCH
/
/
/
2
153, JCH
1
7 Hz), 131.6 (dt, JCH
ꢁ
/
ꢁ
/
ꢁ
/
0.201 mmol) in CH2Cl2 (40 ml) was added NaOMe in
a fivefold molar amount (0.054 g, 0.999 mmol). The
solution was stirred, at r.t. and under dinitrogen, for 1 h
30 min and its colour changed from violet to dark
orange. The solvent was removed in vacuo yielding an
orange oily residue. Extraction with Et2O followed by
2
162, JCH
1
7 Hz), 130.1 (dd, JCH
2
161, JCH
ꢁ
/
ꢁ
/
ꢁ7 Hz),
/
1
2
1
126.8 (dt, JCH
152 Hz), 121.9 (dt, 1JCH
1JCH 130 Hz), 22.4 (tm, 1JCH
ꢁ
/
158, JCH
157, 2JCH
128 Hz), 20.3 (m), 19.9
130 Hz), 9.8 (q, JCH 128 Hz), 9.4 (tm,
128 Hz). FABꢀMS (m/z): 675 [M]ꢀ, 596 [Mꢂ
Br]ꢀ, 547 [Mꢂ C(Me)Ph)]ꢀ, 469 [Mꢂdepe]ꢀ,
(ÄCÄCÄ
341 [Mꢂdepeꢂ(ÄCÄCÄ
C(Me)Ph)]ꢀ.
(2): Anal. Calc. for C59H78BBrFeP4: C, 65.6; H, 7.7.
Found: C, 66.0; H, 8.1%. IR (KBr, cmꢂ1): n(CÄ
CÄC)
7.2 Hz, 2H, Hp
7.8 Hz, 4H, Ho from
7.8 Hz, 4H, Hm from CÄCÄ
CPh2), 7.33 (m, 8H, Ho from BPh4ꢂ), 7.03 (t, JHH
7.2
Hz, 8H, Hm from BPh4ꢂ), 6.88 (t, JHH
7.1 Hz, 4H, Hp
from BPh4ꢂ), 2.43 (dq, JHP
14.4, JHH
ꢁ
/
6 Hz), 125.8 (dm, JCH
ꢁ
/
ꢁ
/
ꢁ
/
8 Hz), 33.1 (qqnt,
ꢁ
/
ꢁ
/
1
1
(tm, JCH
ꢁ
/
ꢁ
/
1JCH
ꢁ
/
/
filtration, concentration and cooling at ca. ꢂ20 8C
/
/
/
/
/
/
resulted in the precipitation of 3 as a dark orange solid.
This precipitate was isolated by filtration and dried in
vacuo. Yield: 55% (0.075 g).
/
/
/
/
/
/
/
(3): Anal. Calc. for C30H55BrFeP4: C, 54.0; H, 8.3.
1
Found: C, 54.0; H, 8.0%. IR (KBr, cmꢂ1): n(CÅ
/
C) 2020
C) 1552 (m). H-NMR (C6D6): d 7.69 (d, Jꢁ
7.2 Hz, 2H, Ho from ÃCÅCÃC(ÄCH2)(C6H5)), 7.17 (t,
Jꢁ 7.4 Hz, 1H, Hp from ÃCÅCÃC(ÄCH2)(C6H5)), 7.10
(m, 2H, Hm from ÃCÅCÃC(ÄCH2)(C6H5)), 5.35 (d,
2Jꢁ
2.1 Hz, 1H, ÃCÅCÃC(ÄCH2)Ph), 5.07 (d, Jꢁ
Hz, 1H, ÃCÅCÃC(ÄCH2)Ph), 2.53 (dq, JHP 14.8 and
Jꢁ7.4 Hz, 4H,
14(CH3CH2)2PCH2CH2P(CH2CH3)2),
2.41 (dq, JHP 15.0 and Jꢁ7.5 Hz, 4H,
14(CH3-
CH2)2PCH2CH2P(CH2CH3)2), 1.80Á1.58 (m, 16H,
1876 (s). H-NMR: d 7.72 (t, JHH
from CÄCÄCPh2), 7.62 (d, JHH
CÄCÄCPh2), 7.37 (t, JHH
ꢁ
/
1
/
/
ꢁ
/
(s), n(CÄ
/
/
/
/
ꢁ
/
/
/
/
/
/
/
ꢁ
/
/
/
/
/
/
ꢁ
/
/
/
/
/
1
2
ꢁ
/
ꢁ/7.2 Hz, 4H,
/
4
/
/
/
/
/
/
1.8
1
2
/
/
/
/
ꢁ
/
(CH3CH2)2PCH2CH2P(CH2CH3)2), 2.09 (m, 4H,
(CH3CH2)2PCH2CH2P(CH2CH3)2), 1.86 (m, 4H,
(CH3CH2)2PCH2CH2P(CH2CH3)2), 1.68 (dq, JHP
/
/
/
1
/
2
ꢁ
/
/
/
ꢁ
/
1
/
2
15.2, JHH
ꢁ/7.6 Hz, 8H,
/
12(CH3CH2)2PCH2CH2P-
/

320
A.I.F. Venaˆncio et al. / Journal of Organometallic Chemistry 684 (2003) 315Á321
/
(CH3CH2)2PCH2CH2P(CH2CH3)2 and (CH3CH2)2-
PCH2CH2P(CH2CH3)2), 1.08 (m, 24H, (CH3-
(CH2CH3)2). 31PÁ
/
{1H}-NMR (C6D6): d 70.3 ppm (s).
146.5 (s,b, Ci from CÃ
CÅ
CÅCÃ
CÅCÃ
C(H)(C6H5)2),
28 Hz, Ca), 47.7 (m,
12 Hz, (CH3CH2)2PCH2CH2P-
20.0 (m, (CH3CH2)2PCH2CH2P-
(CH2CH3)2), 10.2 (s,
12(CH3CH2)2PCH2CH2P(CH2-
CH3)2), 9.7 (s,
12(CH3CH2)2PCH2CH2P(CH2CH3)2).
13CÁ{1H}-NMR:
/
d
Ã
/
/
/
CH2)2PCH2CH2P(CH2CH3)2). 31PÁ
/
{1H}-NMR (C6-
{1H}-NMR (C6D6): d 143.1
CH2)(C6H5)), 135.9 (qnt, JCP
C(H)(C6H5)2), 128.2 (s, Co or Cm from
C(H)(C6H5)2), 128.2 (s, Cm or Co from
C(H)(C6H5)2), 125.7 (s, Cp from Ã
118.2 (m, Cb), 113.5 (qnt, JCP
Cg), 20.9 (qnt, JCP
(CH2CH3)2), 20.4Á
Ã
/
/
/
D6): d 67.4 ppm (s). 13CÁ
(m, Ci from ÃCÅCÃC(Ä
2 Hz, Cb or Cg), 135.7 (qnt, JCP
Cp from ÃCÅCÃC(ÄCH2)(C6H5)), 128.6 (s, Co from Ã
CÅCÃC(ÄCH2)(C6H5)), 127.6 (s, Cm from ÃCÅCÃC(Ä
CH2)(C6H5)), 123.0 (m, Cg or Cb), 111.0 (qnt, JCP
Hz, CÅCÃC(ÄCH2)Ph), 21.7 (qnt, JCP 11 Hz,
(CH3CH2)2PCH2CH2P(CH2CH3)2), 21.4 (qnt, JCPꢁ5
/
Ã
/
/
/
/
/
/
/
ꢁ
/
/
CÅ
/
CÃ
/
2
2
ꢁ
/
28 Hz, Ca), 129.0 (s,
ꢁ
/
/
/
/
/
/
ꢁ
/
/
/
/
/
/
/
/
/
5
ꢁ2
/
/
Ã
/
/
/
/
ꢁ
/
/
/
13C-NMR: d 146.5 (m), 128.2 (d,b, JCH
1
128.2 (d,b, JCH
ꢁ159 Hz),
/
1
Hz,
/
12(CH3CH2)2PCH2CH2P(CH2CH3)2), 21.2 (qnt,
4 Hz,
12(CH3CH2)2PCH2CH2P(CH2CH3)2), 10.9
2 Hz,
12(CH3CH2)2PCH2CH2P(CH2CH3)2),
10.4 (qnt, JCP Hz,
12(CH3CH2)2PCH2CH2P-
1
159 Hz), 125.7 (dt, JCH
ꢁ
/
ꢁ160,
/
1
6 Hz), 118.2 (m), 113.5 (qnt), 47.7 (dm, JCH
2JCH
127 Hz), 20.9 (tm, JCH
ꢁ
/
ꢁ
/
JCP
ꢁ
/
/
1
ꢁ
/
132 Hz), 20.4Á
/
20.0 (m), 10.2
126 Hz). FABꢀMS
H]ꢀ, 659 [MꢂBr]ꢀ, 547
C(H)Ph2)]ꢀ, 532 [Mꢂdepe]ꢀ, 341 [Mꢂ
CÃ
C(H)Ph2)]ꢀ.
(qnt, JCP
ꢁ
/
/
1
1
(q, JCH
(m/z): 738 [M]ꢀ, 737 [Mꢂ
[Mꢂ(ÃCÅCÃ
depeꢂ(ÃCÅ
ꢁ
/
126 Hz), 9.7 (q, JCH
ꢁ
/
ꢁ
/
2
/
/
/
(CH2CH3)2). 13C-NMR (C6D6): d 143.1 (m), 135.9
/
/
/
/
/
/
1
(m), 135.7 (qnt), 129.0 (dm, JCH
ꢁ158 Hz), 128.6 (dd,
/
/
/
/
/
1JCH
ꢁ
/
158, 2JCH
ꢁ
/
7 Hz), 127.6 (dt, 1JCH
ꢁ
/
164, 2JCH
CÅCÃ
127 Hz),
127 Hz).
Br]ꢀ, 547 [Mꢂ
(Ã
depe]ꢀ, 341 [Mꢂ
ꢁ
/
1
8 Hz), 123.0 (m), 111.0 (tqnt, JCH
ꢁ
/
158 Hz, Ã
/
/
/
4.2.4. Reaction of trans-[FeBr{Ã
(depe)2] (3) with HBF4
To a solution of the enynyl complex trans-[FeBr{Ã
CÃC(ÄCH2)Ph}(depe)2] (3) (0.060 g, 0.089 mmol) in
/
CÅ
/
CÃ
/
C(Ä
/
CH2)Ph}
1
C(Ä
10.9 (qm, JCH
FABꢀMS (m/z): 675 [M]ꢀ, 596 [Mꢂ
CÅCÃC(Ä
CH2)Ph)]ꢀ, 469 [Mꢂ
depeꢂ(ÃCÅCÃC(Ä
CH2)Ph)]ꢀ.
/
CH2)Ph), 21.7, 21.4 and 21.2 (tm, JCH
ꢁ
/
1
1
ꢁ
/
127 Hz), 10.4 (qm, JCH
ꢁ
/
/
CÅ
/
/
/
/
/
/
/
/
/
/
/
CH2Cl2 (20 ml) was added a slight excess (1.2:1) of
HBF4 (0.107 mmol, ca. 15 ml of a 54% solution in Et2O).
The colour of the solution changed immediately from
dark orange to violet. It was concentrated and addition
of Et2O (ca. 10 cm3) led to the precipitation of the
allenylidene complex 1, although with [BF4]ꢂ as the
counterion, as a violet solid which was isolated by
filtration and dried in vacuo. IR, 1H and 31PÁ{1H}-
NMR (spectra identical to those of 1, except the features
concerning the different counterions) confirmed the
formulation.
/
/
/
/
/
4.2.3. Alkynyl complex trans-[FeBr{Ã
(H)Ph2}(depe)2] (4)
To a stirred CH2Cl2 (30 ml) solution of the allenyli-
dene complex trans-[FeBr(ÄCÄCÄCPh2)(depe)2][BPh4]
/
Cꢁ
/
CÃ/C
/
/
/
/
(0.20 g, 0.189 mmol) was added a slight excess of
K[B{CH(Me)Et}3H] (208 ml of a 1 M THF solution)
and the system was left with stirring at r.t. and under
dinitrogen for ca. 30 min. The colour changed from dark
blue to dark orange. The solvent was removed in vacuo
yielding an oily residue. Extraction with Et2O followed
Acknowledgements
by filtration, concentration and cooling at ca. ꢂ18 8C
/
led to the precipitation of 4 as an orange solid which was
separated by filtration and dried in vacuo. Yield: 60%
(0.080 g).
The work has been partially supported by the
Fundacao para a Cieˆncia e a Tecnologia (FCT) and
¸˜
by the PRAXIS XXI and POCTI FEDER funded
Programmes. We also thank Dr. M. Caˆndida Vaz
(Instituto Superior Te´cnico) for the elemental analysis
services and Mr. Indale´cio Marques (Centro de Qu´ımica
Estrutural) for running the FABMS spectra.
(4): Anal. Calc. for C35H59BrFeP4: C, 55.0; H, 7.9.
Found: C, 55.0; H, 8.5%. IR (KBr, cmꢂ1): n(CÅ
/
C) 2057
(m). 1H-NMR (C6D6): d 7.23Á
Hp from ÃCÅCÃC(H)(C6H5)2), 4.91 (s,b, 1H, Ã
C(H)Ph2), 2.36 (dq, JHP 15.2, JHH 7.6 Hz, 4H,
(CH3CH2)2PCH2CH2P(CH2CH3)2), 2.26 (dq, JHP
15.2, JHH 7.6 Hz, 4H,
14(CH3CH2)2PCH2CH2P-
(CH2CH3)2), 1.90 (m, 8H, (CH3CH2)2PCH2CH2P-
/
7.09 (m, 10H, Ho,Hm and
/
/
/
/
CÅ
/
CÃ
/
1
/
ꢁ
/
ꢁ
/
4
ꢁ
/
ꢁ
/
/
References
1
[1] V. Cadierno, J. D´ıez, M.P. Gamasa, J. Gimeno, E. Lastra, Coord.
(CH2CH3)2), 1.79 (dq, JHP
(CH3CH2)2PCH2CH2P(CH2CH3)2), 1.64 (dq, JHP
14.8, JHH 7.4 Hz, 4H,
14(CH3CH2)2PCH2CH2P-
12(CH3CH2)2PCH2CH2P-
12(CH3CH2)2PCH2CH2P-
ꢁ/15.2, JHH
ꢁ
/
7.6 Hz, 4H,
/
4
Chem. Rev. 193Á
/
195 (1999) 147.
ꢁ
/
[2] D. Touchard, P.H. Dixneuf, Coord. Chem. Rev. 178Á
/180 (1998)
ꢁ
/
/
409.
[3] M.I. Bruce, Chem. Rev. 98 (1998) 2797.
(CH2CH3)2), 1.20 (m, 12H,
(CH2CH3)2), 1.13 (m, 12H,
/
[4] H. Werner, J. Chem. Soc. Chem. Commun. (1997) 903.
[5] J.P. Selegue, Organometallics 1 (1982) 217.
/

A.I.F. Venaˆncio et al. / Journal of Organometallic Chemistry 684 (2003) 315Á
/321
321
[6] G. Roth, H. Fischer, T. Meyer-Friedrichsen, J. Heck, S.
Houbrechts, A. Persoons, Organometallics 17 (1998) 1511.
[7] M. Tamm, T. Jentzsh, W. Werncke, Organometallics 16 (1997)
1418.
[29] A.J.L. Pombeiro, J. Organomet. Chem. 632 (2001) 215.
[30] M. Kuznetsov, A.J.L. Pombeiro, A.I. Dement’ev, J. Chem. Soc.
Dalton Trans. (2000) 4413.
[31] M.F.N.N. Carvalho, A.J.L. Pombeiro, G. Wagner, B. Pedersen,
R. Herrmann, Z. Naturforsch. B54 (1999) 725.
[8] V. Cadierno, M.P. Gamasa, J. Gimeno, Eur. J. Inorg. Chem.
(2001) 571.
[32] M.F.N.N. Carvalho, S.S.P.R. Almeida, A.J.L. Pombeiro, R.A.
Henderson, Organometallics 16 (1997) 5441.
[9] S.N. Osipov, O.I. Artyushin, A.F. Kolomiets, C. Bruneau, M.
Picquet, P.H. Dixneuf, Eur. J. Org. Chem. (2001) 3891.
[10] D. Se´meril, J. Le Noˆtre, C. Bruneau, P.H. Dixneuf, A.F.
Kolomiets, S.N. Osipov, New J. Chem. 25 (2000) 16.
[11] K.J. Harlow, A.F. Hill, J.D.E.T. Wilton-Ely, J. Chem. Soc.
Dalton Trans. (1999) 285.
[33] S.S.P.R. Almeida, A.J.L. Pombeiro, Organometallics 16 (1997)
4469.
[34] A.J.L. Pombeiro, Chemistry and electrochemistry of alkyne- and
isocyanide-derived carbyne complexes of rhenium, molybdenum
and tungsten, in: F.R. Kreissl (Ed.), Transition Metal Carbyne
Complexes, NATO ASI Series, Kluwer Academic Publishers,
Dordrecht, The Netherlands, 1993, p. 105.
[12] L. Jafarpour, J. Huang, E.D. Stevens, S.P. Nolan, Organome-
tallics 18 (1999) 3760.
[13] A. Furstner, A.F. Hill, M. Liebl, J.D.E.T. Wilton-Ely, Chem.
¨
[35] A.J.L. Pombeiro, S.S.P.R. Almeida, M.F.C. Guedes da Silva, J.
Chem. Soc. Dalton Trans. (1989) 2381.
Commun. (1999) 615.
[14] M. Picquet, C. Bruneau, P.H. Dixneuf, Chem. Commun. (1998)
2249.
[15] A. Furstner, M. Picquet, C. Bruneau, P.H. Dixneuf, Chem.
¨
[36] L. Zhang, M.F.C. Guedes da Silva, M.L. Kuznetsov, M.P.
Gamasa, J. Gimeno, J.J.R. Frau´sto, A.J.L. Pombeiro, Organo-
metallics 20 (2001) 2782.
Commun. (1998) 1315.
[16] Y. Nishibayashi, Y. Inada, M. Hidai, S. Uemura, J. Am. Chem.
Soc. 124 (2002) 7900.
[37] L. Zhang, M.P. Gamasa, J. Gimeno, M.F.C. Guedes da Silva,
A.J.L. Pombeiro, C. Graiff, M. Lanfranchi, A. Tiripicchio, Eur. J.
Inorg. Chem. (2000) 1707.
[17] Y. Nishibayashi, I. Wakiji, Y. Ishii, S. Uemura, M. Hidai, J. Am.
Chem. Soc. 123 (2001) 3393.
[38] L. Zhang, M.P. Gamasa, J. Gimeno, R.J. Carbajo, F. Lo´pez-
Ortiz, M.F.C. Guedes da Silva, A.J.L. Pombeiro, Eur. J. Inorg.
Chem. (2000) 341.
[18] Y. Nishibayashi, I. Wakiji, M. Hidai, J. Am. Chem. Soc. 122
(2000) 11019.
[39] H. Berke, P. Harter, G. Huttner, L. Zsolnai, Chem. Ber. 115
¨
(1982) 695.
[19] J.L. Pail, S. De´rien, C. Bruneau, B. Demerseman, L. Toupet, P.H.
Dixneuf, Angew. Chem. Int. Ed. 40 (2001) 2912.
[20] B.M. Trost, M.T. Rudd, J. Am. Chem. Soc. 123 (2001) 8862.
[21] A.I.F. Venaˆncio, L.M.D.R.S. Martins, J.J.R. Frau´sto da Silva,
A.J.L. Pombeiro, Inorg. Chem. Commun. 6 (2003) 94.
[22] G. Albertin, P. Agnoletto, S. Antoniutti, Polyhedron 21 (2002)
1755.
[40] H. Berke, Chem. Ber. 113 (1980) 1370.
[41] I. de los Rios, M.J. Tenorio, M.C. Puerta, P. Valerga, J.
Organomet. Chem. 549 (1997) 221.
[42] M. Baya, P. Crochet, M.A. Esteruelas, E. Gutie´rrez-Puebla, A.M.
Lo´pez, J. Modrego, E. Onate, N. Vela, Organometallics 19 (2000)
˜
2585.
[43] M.I. Bruce, P. Hinterding, P.J. Low, B.W. Skelton, A.H. White,
Chem. Commun. (1996) 1009.
[23] E. Gatto, G. Gervasio, D. Marabello, E. Sappa, J. Chem. Soc.
Dalton Trans. (2001) 1485.
[24] A.I.F. Venaˆncio, L.M.D.R.S. Martins, J.J.R. Frau´sto da Silva,
A.J.L. Pombeiro, Port. Electroch. Acta 19 (2001) 361.
[25] V. Guilaume, P. Thominot, F. Coat, A. Mari, C. Lapinte, J.
Organomet. Chem. 565 (1998) 75.
[44] D. Touchard, N. Pirio, P.H. Dixneuf, Organometallics 14 (1995)
4920.
[45] S. Rigaut, O. Maury, D. Touchard, P.H. Dixneuf, Chem.
Commun. (2001) 373.
[26] C. Gauss, D. Veghini, O. Omara, H. Berke, J. Organomet. Chem.
541 (1997) 19.
[46] N. Mantovani, L. Marvelli, R. Rossi, C. Bianchini, I. de los Rios,
A. Romerosa, M. Peruzzini, J. Chem. Soc. Dalton Trans. (2001)
2353.
[27] S. Nakanishi, K. Goda, S. Uchiyama, Y. Otsuji, Bull. Chem. Soc.
Jpn. 65 (1992) 2560.
[28] H. Berke, V. Grossmann, G. Huttner, L. Zsolnai, Chem. Ber. 117
¨
[47] D.J. Evans, R.A. Henderson, A. Hills, D.L. Hughes, K.E. Oglive,
J. Chem. Soc. Dalton Trans. (1992) 1259.
[48] A. Wold, J.K. Ruff, Inorg. Synth. 14 (1973) 102.
(1984) 3432.