Novel dimetal bridging carbene complexes derived from a terminal carbonyl dimetal compound. Syntheses, structures and reactivities of 7H-indene-coordinated diiron bridging carbene complexes

Article abstract of DOI:10.1039/b607283f

Pentacarbonyl-7H-indenediiron, [Fe₂(CO)₅(η ³,η⁵-C₉H₈)] (1), reacts with aryllithium, ArLi (Ar = C₆H₅, p-C₆H ₅C₆H₄), followed by alkylation with Et ₃OBF₄ to give novel 7H-indene-coordinated diiron bridging alkoxycarbene complexes [Fe₂(-C(OC₂H ₅)Ar)(CO)₄(η⁴,η⁴-C ₉H₈)] (2, Ar = C₆H₅; 3, Ar = p-C₆H₅C₆H₄). Complexes 2 and 3 react with HBF₄·Et₂O at low temperature to yield cationic bridging carbyne complexes [Fe₂(-CAr)(CO) ₄(η⁴,η⁴-C₉H ₈)]BF₄ (4, Ar = C₆H₅; 5, Ar = p-C₆H₅C₆H₄). Cationic 4 and 5 react with NaBH₄ in THF at low temperature to afford diiron bridging arylcarbene complexes [Fe₂(-C(H)Ar)(CO)₄(η ⁴,η⁴-C₉H₈)] (6, Ar = C ₆H₅; 7, Ar = p-C₆H₅C ₆H₄). The similar reactions of 4 and 5 with NaSC ₆H₄CH₃-p produce the bridging arylthiocarbene complexes [Fe₂(-C(Ar)SC₆H₄CH ₃-p)(CO)₄(η⁴,η⁴-C ₉H₈)] (8, Ar = C₆H₅; 9, Ar = p-C₆H₅C₆H₄). Cationic 4 and 5 can also react with anionic carbonylmetal compounds Na[M(CO)₅(CN)] (M = Cr, Mo, W) to give the diiron bridging aryl(pentacarbonylcyanometal)carbene complexes [Fe₂(-C(Ar)NCM(CO)₅)(CO)₄(η ⁴,η⁴-C₉H₈)] (10, Ar = C ₆H₅, M = Cr; 11, Ar = p-C₆H₅C ₆H₄, M = Cr; 12, Ar = C₆H₅, M = Mo; 13, Ar = p-C₆H₅C₆H₄, M = Mo; 14, Ar = C₆H₅, M = W; 15, Ar = p-C₆H₅C ₆H₄, M = W). Interestingly, in CH₂Cl ₂ solution at room temperature complexes 10-15 were transformed into the isomerized 7H-indene-coordinated monoiron complexes [Fe(CO) ₂(η⁵-C₉H₈)C(Ar)NCM(CO) ₅] (16, Ar = C₆H₅, M = Cr; 17, Ar = p-C ₆H₅C₆H₄, M = Cr; 18, Ar = C ₆H₅, M = Mo; 19, Ar = p-C₆H₅C ₆H₄, M = Mo; 20, Ar = C₆H₅, M = W; 21, Ar = p-C₆H₅C₆H₄, M = W), while complex 3 was converted into a novel ring addition product [Fe ₂(C(OC₂H₅)C₆H₄C ₆H₅-p-(η²,η⁵-C ₉H₈))(CO)₅] (22) under the same conditions. The structures of complexes 2, 6, 8, 14, 18 and 22 have been established by X-ray diffraction studies. The Royal Society of Chemistry 2006.

Full text of DOI:10.1039/b607283f

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PAPER
www.rsc.org/dalton | Dalton Transactions
Novel dimetal bridging carbene complexes derived from a terminal carbonyl
dimetal compound. Syntheses, structures and reactivities of
7H-indene-coordinated diiron bridging carbene complexes
Lei Zhang,a Jie Sun,a Huping Zhu,a Qiang Xu,*b Nobuko Tsumori*c and Jiabi Chen*a
Received 23rd May 2006, Accepted 27th June 2006
First published as an Advance Article on the web 12th July 2006
DOI: 10.1039/b607283f
3
5
Pentacarbonyl-7H-indenediiron, [Fe2(CO)5(g ,g -C9H8)] (1), reacts with aryllithium, ArLi (Ar = C6H5,
p-C6H5C6H4), followed by alkylation with Et3OBF4 to give novel 7H-indene-coordinated diiron
4
4
bridging alkoxycarbene complexes [Fe2{l-C(OC2H5)Ar}(CO)4(g ,g -C9H8)] (2, Ar = C6H5; 3, Ar =
p-C6H5C6H4). Complexes 2 and 3 react with HBF4·Et2O at low temperature to yield cationic bridging
4
4
carbyne complexes [Fe2(l-CAr)(CO)4(g ,g -C9H8)]BF4 (4, Ar = C6H5; 5, Ar = p-C6H5C6H4). Cationic 4
and 5 react with NaBH4 in THF at low temperature to afford diiron bridging arylcarbene complexes
4
4
[Fe2{l-C(H)Ar}(CO)4(g ,g -C9H8)] (6, Ar = C6H5; 7, Ar = p-C6H5C6H4). The similar reactions of 4 and
5 with NaSC6H4CH3-p produce the bridging arylthiocarbene complexes [Fe2{l-C(Ar)SC6H4CH3-p}-
4
4
(CO)4(g ,g -C9H8)] (8, Ar = C6H5; 9, Ar = p-C6H5C6H4). Cationic 4 and 5 can also react with anionic
carbonylmetal compounds Na[M(CO)5(CN)] (M = Cr, Mo, W) to give the diiron bridging
4
4
aryl(pentacarbonylcyanometal)carbene complexes [Fe2{l-C(Ar)NCM(CO)5}(CO)4(g ,g -C9H8)] (10,
Ar = C6H5, M = Cr; 11, Ar = p-C6H5C6H4, M = Cr; 12, Ar = C6H5, M = Mo; 13, Ar =
p-C6H5C6H4, M = Mo; 14, Ar = C6H5, M = W; 15, Ar = p-C6H5C6H4, M = W). Interestingly, in
CH2Cl2 solution at room temperature complexes 10–15 were transformed into the isomerized
5
7H-indene-coordinated monoiron complexes [Fe(CO)2(g -C9H8)C(Ar)NCM(CO)5] (16, Ar =
C6H5, M = Cr; 17, Ar = p-C6H5C6H4, M = Cr; 18, Ar = C6H5, M = Mo; 19, Ar = p-C6H5C6H4, M =
Mo; 20, Ar = C6H5, M = W; 21, Ar = p-C6H5C6H4, M = W), while complex 3 was converted into a
2
5
novel ring addition product [Fe2{C(OC2H5)C6H4C6H5-p-(g ,g -C9H8)}(CO)5] (22) under the same
conditions. The structures of complexes 2, 6, 8, 14, 18 and 22 have been established by X-ray diffraction
studies.
reagents followed by alkylation with Et3BF4 to give diiron
Introduction
8
bridging alkoxycarbene complexes [Fe2{l-C(OEt)Ar}(CO)4(g -
5
C8H8)],7 [Fe2(l-CO){l-C(OEt)Ar}(CO)2(g -C5H5)2],8 and [Fe2(l-
The chemistry of di- and polynuclear metal bridging carbene
and bridging carbyne complexes has been receiving considerable
current attention, largely because of the interesting chemical
properties exhibited by such complexes. A number of di- and
polymetal complexes containing bridging carbene and carbyne
ligands have been synthesized by Stone et al.1,2 and a series
of diiron bridging carbene and carbyne complexes have also
been reported.3–6 In continuation of our interest in developing
the methodologies of the synthesis of olefin-coordinated metal
carbene and carbyne complexes, we have found a facile method for
preparation of the dimetal bridging carbene and bridging carbyne
complexes that is to conduct the reactions of olefin-ligated
dimetal carbonyl compounds bearing a bridging CO ligand,
5
CO){l-C(OC2H5)Ar}(CO)2{(g -C5H4)2Si(CH3)2}],9 respectively.
However, only one example of olefin-coordinated dimetal
bridging carbyne complex which was synthesized from a terminal
carbonyl-ligated dimetal compound (bearing no bridging CO
ligand) is known10 and no example of dimetal bridging carbene
complex synthesized in this way has been reported up to now.
Recently, we have shown a new and convenient method for the
preparation of di- and polymetal bridging carbene and/or
bridging carbyne complexes: the reactions of diiron cationic
5
bridging carbyne complexes [Fe2(l-CO)(l-CAr)(CO)2(g -
5
C5H5)2]BBr4,11 [Fe2(l-CO)(l-CAr)(CO)2{(g -C5H4)2Si(CH3)2}]-
8
13
BBr4,12 and [Fe2(l-CAr)(CO)4(g -C8H8)]BF4
obtained by
8
5
such as [Fe2(l-CO)(CO)4(g -C8H8)], [Fe2(l-CO)2(CO)2(g -C5H5)2]
and [Fe2(l-CO)2(CO)2{SiMe2(g -C5H5)2}], with aryllithium
treating above corresponding diiron bridging alkoxycarbene
complexes with Lewis acid BBr3 or HBF4, with nucleophiles
involving carbonylmetal anions. This offers an useful method for
the preparation and structural modification of dimetal bridging
carbene complexes.
On the other hand, it was found that the olefin ligands in dimetal
carbonyl compounds exhibit a great influence on their reactivity
towards aryllithium reagents and resulting products,7–10,14 and that
the different olefin ligands in the dimetal cationic bridging carbyne
5
aState Key Laboratory of Organometallic Chemistry, Shanghai Institute of
Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai,
200032, China
bNational Institute of Advanced Industrial Science and Technology (AIST),
1-8-31 Midorigaoka, Ikeda, Osaka, 563-8577, Japan
cToyama National College of Technology, 13 Hongo-machi, Toyama-shi,
939-8630, Japan
4348 | Dalton Trans., 2006, 4348–4358
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complexes also exhibit a great influence on their reactivities
towards nucleophiles and the resulting products.11,12,15
red solid residue obtained was added Et3OBF421 (ca. 5 g). This solid
mixture was dissolved in 50 mL of N2-saturated water at 0 ◦C with
vigorous stirring and the mixture covered with petroleum ether
To develop the new synthetic method for the preparation
of di- and polymetallic bridging carbene and bridging carbyne
complexes and to further explore the reactivity of the diiron
cationic bridging carbyne complexes containing different cy-
cloolefin ligands towards nucleophiles, we investigated the reaction
◦
(bp 30–60 C). Immediately afterwards, Et3OBF4 (ca. 15 g) was
added portionwise to the aqueous solution, with strong stirring,
until it became acidic. The aqueous solution was extracted with
petroleum ether. After removal of the solvent under vacuum, the
dark brown residue was chromatographed on an alumina (neutral)
column (1.6 × 15–20 cm) at −25 ◦C with petroleum ether–CH2Cl2
(15 : 1) as the eluent. The red band was eluted and collected.
After removal of the solvent, the residue was recrystallized from
petroleum ether at −80 ◦C to give 1.12 g (86%, based on 1) of red
crystals of 2; mp 84–86 ◦C (decomp.); IR (CH2Cl2) m(CO) 2019 (m),
1972 (vs), 1951 (w), 1911 (s) cm−1; MS: m/z 446 (M+ − CO), 418
(M+ − 2CO), 390 (M+ − 3CO), 362 (M+ − 4CO), 86 (C6H14+).
Anal. Calc. for C22H18O5Fe2·0.5C6H14 (hexane): C, 58.06; H, 4.87.
Found: C, 57.59; H, 4.70%.
3
5
of pentacarbonyl-7H-indenediiron, [Fe2(CO)5(g ,g -C9H8)] (1),
a dimetal compound bearing only terminal CO ligands, with
aryllithium reagents, which gave a new type of 7H-indene-
coordinated diiron bridging alkoxycarbene complexes [Fe2{l-
4
4
C(OC2H5)Ar}(CO)4(g ,g -C9H8)] (Ar = C6H5, p-C6H5C6H4) and
carried out the study of the reactivities of their cationic bridging
carbyne complexes towards nucleophiles involving carbonylmetal
anions. These reactions produce a series of novel dimetal bridg-
ing carbene complexes. In this paper, we report these unusual
reactions and the structural characterizations of the resulting
products.
Reaction of 1 with p-C6H5C6H4Li to give
[Fe2{l-C(OC2H5)C6H4C6H5-p}(CO)4(g4,g4-C9H8)] (3)
Experimental
A solution of 0.280 g (1.20 mmol) of p-C6H5C6H4Br in 20 mL
of ether was mixed with 1.30 mmol of n-C4H9Li. After 1–2 h
stirring at room temperature, the resulting ether solution of p-
C6H5C6H4Li20 was reacted, as described for the reaction of 1 with
C6H5Li, with 0.370 g (1.00 mmol) of 1 at −60 to −30 ◦C for 3 h.
Further treatment of the resulting mixture as described for the
preparation of 2 yielded 0.432 g (79%, based on 1) red crystalline
3: mp 74–76 ◦C (decomp.); IR (CH2Cl2) m(CO) 2019 (m), 1973 (vs),
1951 (w), 1911 (s) cm−1; MS m/z 382 (M+ − 4CO − Fe), 337 (M+ −
All procedures were performed under a dry, oxygen-free N2
atmosphere by using standard Schlenk techniques. All solvents
employed were reagent grade and dried by refluxing over ap-
˚
propriate drying agents and stored over 4 A molecular sieves
under N2 atmosphere. THF and Et2O were distilled from sodium
benzophenone ketyl, while petroleum ether (bp 30–60 ◦C) and
CH2Cl2 were distilled from CaH2. The neutral alumina (Al2O3,
100–200 mesh) used for chromatography was deoxygenated at
room temperature under high vacuum for 16 h, deactivated with
5% w/w N2-saturated water and stored under N2 atmosphere.
Compounds HBF4·Et2O, p-C6H5C6H4Br and NaBH4 were pur-
+
4CO − Fe − OC2H5), 116 (C9H8 ). Anal. Calc. for C28H22O5Fe2:
C, 61.13; H, 4.23. Found: C, 61.62; H, 4.54%.
3
5
chased from Aldrich Chemical Co. Compounds [Fe2(CO)5(g ,g -
C9H8)] (1),16 NaSC6H4CH3-p,17 Na[M(CO)5(CN)] (M = Cr, Mo,
Reaction of 2 with HBF4·Et2O to give [Fe2(l-CC6H5)(CO)4(g4,g4-
C9H8)]BF4 (4)
W),18 aryllithium reagents,19,20 and Et3OBF4 were prepared by
21
literature methods.
The IR spectra were measured on a Nicolet AV-360 spectropho-
tometer using NaCl cells with 0.1 mm spacers. The H NMR
and 13C NMR spectra were recorded at ambient temperature in
acetone-d6 solution with TMS as the internal reference using a
To a stirred, red solution of 2 (0.120 g, 0.25 mmol) in 30 mL
of ether at −60 ◦C was added 0.045 mL (0.30 mmol) of
HBF4·Et2O. Immediately, a brick red precipitate was formed. The
mixture was stirred at −60 to −30 ◦C for 1 h. The resulting mixture
was filtered and the solids were washed with ether (2 × 20 mL)
1
1
◦
◦
Varian Mercury 300 spectrometer running at 300 MHz. The H
at −60 C and then dried under high vacuum at −30 C to give
0.120 g (90%, based on 2) of 4 as a brick red solid: IR (CH2Cl2)
and 13C NMR data for compounds 2, 3, 8 and 9 can not be
obtained or assigned due to their easy transformation (for 3)
or other unknown reason. The 13C NMR data for compounds
10–15 were not obtained since they were easily transformed into
monoiron complexes 16–21. Electron ionization mass spectra
(EIMS) were run on a Hewlett Packard 5989A spectrometer.
Melting points obtained on samples in sealed nitrogen-filled
capillaries are uncorrected.
1
m(CO) 2074 (s), 2047 (vs), 2025 (m), 2005 (m) cm−1; H NMR
(CD3COCD3) d 7.79–7.66 (m, 5H, C6H5), 7.17 (d, 1H, C9H8, J =
2.7), 6.67 (s, 2H, C9H8,), 5.86 (s, 1H, C9H8), 5.64 (s, 1H, C9H8),
4.23 (s, 1H, C9H8), 1.89 (d, 1H, C9H8, J = 9.6), 1.02 (dd, 1H, C9H8,
J = 7.5, 9.3).
Preparation of [Fe2(l-CC6H5C6H4-p)(CO)4(g4,g4-C9H8)]BF4 (5)
This complex was prepared in a manner similar to that for 4 using
3 (0.100 g, 0.18 mmol) and HBF4·Et2O (0.040 mL, 0.27 mmol).
A brick red solid product of 5 was obtained in a yield of 0.100 g
(95%, based on 3): IR (CH2Cl2) m(CO) 2073 (s), 2046 (vs), 2024
(m), 2003 (m) cm−1; 1H NMR (CD3COCD3) d 8.01–7.49 (m, 9H,
C6H5C6H4), 7.17 (d, 1H, C9H8, J = 2.4), 6.68 (dd, 2H, C9H8, J =
1.2, 5.2), 5.88 (d, 1H, C9H8, J = 0.9), 5.66 (dd, 1H, C9H8, J = 0.9,
2.1), 4.23 (s, 1H, C9H8), 1.92 (d, 1H, C9H8, J = 9.9), 1.11 (d, 1H,
C9H8, J = 6.9).
Reaction of [Fe2(CO)5(g3,g5-C9H8)] (1) with C6H5Li to give
[Fe2{l-C(OC2H5)C6H5}(CO)4(g4,g4-C9H8)] (2)
To a solution of 1.0 g (2.71 mmol) of 1 dissolved in 50 mL of
ether at −60 ◦C was added 3.23 mmol of the freshly prepared
C6H5Li19 ether solution with stirring. The reaction mixture was
stirred at −60 to −30 ◦C for 3 h, during which time the clear red
solution gradually turned turbid solution. The resulting solution
then evaporated under high vacuum at −30 ◦C to dryness. To the
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Reaction of 4 with NaBH4 to give
band was collected. After vacuum removal of the solvent, the
residue was recrystallized from petroleum ether–CH2Cl2 solution
at −80 ◦C to afford 0.108 g (71%, based on 2) of brown–red
crystalline 8: mp 72–74 ◦C (decomp.); IR (CH2Cl2) m(CO) 2017
(m), 1982 (vs), 1960 (m), 1939 (s) cm−1; MS m/z 317 (M+ − 4CO −
[Fe2{l-C(H)C6H5}(CO)4(g4,g4-C9H8)] (6)
To a suspension of 4, freshly prepared (in situ) 4 by reaction of
2 (0.200 g, 0.42 mmol) with HBF4·Et2O (0.045 mL, 0.30 mmol),
in 50 mL of THF at −80 ◦C was added 0.020 g (0.53 mmol)
of NaBH4. The solution turned from a brick turbid solution to
a deep red gradually. After stirring at −80 to −40 ◦C for 2–
3 h, the resulting solution was evaporated in vacuo at −40 ◦C
to dryness and residue was chromatographed on an Al2O3 column
CH3C6H4S), 261 (M+ − 4CO − Fe − CH3C6H4S), 172 [M+
−
4CO − Fe − C(C6H5)SC6H4CH3], 115 (C9H8 − 1)+. Anal. Calc.
for C27H20O4SFe2: C, 58.73; H, 3.65. Found: C, 58.51; H, 3.80%.
Reaction of 5 with NaSC6H4CH3-p to give
◦
at −25 C with petroleum ether–CH2Cl2 (5 : 2) as the eluent. A
[Fe2{l-C(C6H4C6H5-p)SC6H4CH3-p}(CO)4(g4,g4-C9H8)] (9)
brown–red band was eluted and collected. After vacuum removal
of the solvent, the residue◦was recrystallized from petroleum ether–
CH2Cl2 solution at −80 C to give 0.132 g (73%, based on 2) of
brown–red crystals of 6: mp 152–154 ◦C (decomp.); IR (CH2Cl2)
Freshly prepared (in situ) 5 by the reaction of 3 (0.100 g, 0.18 mmol)
with HBF4·Et2O (0.040 mL, 0.27 mmol) was treated, in a manner
similar to that described for the preparation of 4, with 0.040 g
(0.27 mmol) of NaSC6H4CH3-p at −80 to −40 ◦C for 3 h. The
resulting solution was worked up as described for the preparation
of 8 to yield 0.100 g (87%, based on 3) of 9 as brown–red crystals:
mp 124–126 ◦C; IR (CH2Cl2) m(CO) 2018 (s), 1981 (vs), 1961 (m),
m(CO) 2017 (s), 1976 (vs), 1957 (m), 1912 (m) cm−1; H NMR
1
(CD3COCD3) d 7.66–7.06 (m, 5H, C6H5), 7.08 (s, 1H, l-CH), 5.97
(t, 1H, C9H8, J = 2.4), 5.31 (dd, 1H, C9H8, J = 0.6, 6.0), 4.93 (s,
1H, C9H8), 3.87 (m, 1H, C9H8), 3.68 (d, 1H, C9H8, J = 2.7), 3.23
(d, 1H, C9H8, J = 9.0), 3.05 (t, 1H, C9H8, J = 1.8), 2.63 (dd, 1H,
C9H8, J = 6.9, 10.5); 13C NMR (CD3COCD3) d 222.6, 218.3, 216.8
(CO), 159.2 (l-C), 143.7, 128.5, 127.9, 125.8 (C6H5), 97.7, 94.8,
90.7, 84.9, 78.9, 68.9, 64.4 (C9H8), 48.8; MS m/z 402 (M+ − CO),
374 (M+ − 2CO), 318 (M+ − 4CO), 317 (M+ − 4CO − H), 240
(M+ − 4CO − H − C6H5). Anal. Calc. for C20H14O4Fe2: C, 55.86;
H, 3.28. Found: C, 55.39; H, 3.62%.
1922 (m) cm−1; MS m/z 475 (M+ − C6H5C6H4), 391 (M+
−
3CO − C6H5C6H4), 363 (M+ − 4CO − C6H5C6H4), 240 (M+ −
4CO − C6H5C6H4 − CH3C6H4S), 115 (C9H8 − 1)+. Anal. Calc.
for C33H24O4SFe2: C, 63.08; H, 3.85. Found: C, 63.25; H, 3.86%.
Reaction of 4 with Na[Cr(CO)5(CN)] to give
[Fe2{l-C(C6H5)NCCr(CO)5}(CO)4(g4,g4-C9H8)] (10)
To a suspension of 4, freshly prepared (in situ) from 2 (0.400 g,
0.84 mmol) and HBF4·Et2O (0.200 mL, 1.50 mmol), in 50 mL
of THF at −80 ◦C was added 0.200 g (0.83 mmol) of
[NaCr(CO)5(CN)]. The reaction mixture was stirred at −80 to
Reaction of 5 with NaBH4 to give
[Fe2{l-C(H)C6H4C6H5-p}(CO)4(g4,g4-C9H8)] (7)
Using the same procedures as in the reaction of 4 with NaBH4,
freshly prepared (in situ) 5 from the reaction of 3 (0.100 g,
0.18 mmol) with HBF4·Et2O (0.040 mL, 0.27 mmol), was treated
with 0.010 g (0.27 mmol) of NaBH4 at −80 to −40 ◦C for
3 h. Further treatment of the resulting solution as done for the
preparation of 6 yielded 0.074 g (85%, based on 3) of brown–
red crystals of 7: mp 164–165 ◦C (decomp.); IR (CH2Cl2)
◦
−40 C for 2 h, during which time the turbid solution gradually
turned deep red solution. The resulting solution was evaporated
in vacuo at −40 ◦C to dryness and the residue was chromato-
graphed on Al2O3 at −25 ◦C with petroleum ether–CH2Cl2 (5 :
1) as the eluent. The brown band was eluted and collected. After
vacuum removal of the solvent, the residue was recrystallized from
petroleum ether–CH2Cl2 solution at −80 ◦C to give 0.365 g (67%,
based on 2) of brown–red crystals of 10: mp 102–103 ◦C (decomp.);
IR (CH2Cl2) m(CO) 2053 (m), 2029 (m), 1994 (s), 1974 (m), 1947
m(CO) 2016 (s), 1976 (vs), 1957 (s), 1911 (m) cm−1; H NMR
1
(CD3COCD3) d 7.72–7.32 (m, 9H, p-C6H5C6H4), 7.09 (s, 1H, l-
CH), 6.00 (s, 1H, C9H8), 5.33 (s, 1H, C9H8), 4.94 (s, 1H, C9H8), 3.89
(s, 1H, C9H8), 3.71 (s, 1H, C9H8), 3.25 (d, 1H, C9H8, J = 9.0), 3.08
(s, 1H, C9H8), 2.64 (d, 1H, C9H8, J = 8.4); 13C NMR (CD3COCD3)
d 222.4, 216.5, 215.5, 215.1 (CO), 158.8 (l-C), 142.1, 137.8, 129.4,
128.4, 127.5, 126.9, 126.6 (C6H5), 97.5, 94.7, 90.5, 84.7, 78.7, 68.7,
64.3, 48.6 (C9H8); MS m/z 450 (M+ − 2CO), 394 (M+ − 4CO),
338 (M+ − 4CO − Fe), 185 (M+ − 4CO − Fe − C6H5C6H4), 116
1
(vs, br) cm−1; m(CN) 2115 (w) cm−1; H NMR (CD3COCD3) d
7.89–7.24 (m, 5H, C6H5), 6.37 (t, 1H, C9H8, J = 2.4), 5.70 (t, 1H,
C9H8, J = 2.7), 4.98 (dd, 1H, C9H8, J = 0.6, 2.1), 4.03–3.99 (m,
2H, C9H8), 3.38 (d, 1H, C9H8, J = 9.6), 2.93 (t, 1H, C9H8, J = 1.8),
2.86 (m, 1H, C9H8); MS m/z 540 (M+ − CO − C6H5), 373 [M+ −
2CO − Cr(CO)5CN], 345 [M+ − 3CO − Cr(CO)5CN]. Anal. Calc.
for C26H13O9NCrFe2: C, 48.26; H, 2.03; N, 2.16. Found: C, 48.32,
H, 2.28; N, 2.18%.
+
(C9H8 ). Anal. Calc. for C26H18O4Fe2: C, 61.70; H, 3.58. Found:
C, 61.04; H, 3.67%.
The following complexes were prepared by similar reactions.
Reaction of 4 with NaSC6H4CH3-p to give
[Fe2{l-C(C6H5)SC6H4CH3-p}(CO)4(g4,g4-C9H8)] (8)
[Fe2{l-C(C6H4C6H5-p)NCCr(CO)5}(CO)4(g4,g4-C9H8)] (11)
To a suspension of 4, freshly prepared (in situ) by the reaction of
2 (0.130 g, 0.27 mmol) with HBF4·Et2O (0.050 mL, 0.37 mmol),
Brown–red crystals (70% yield); mp 76–78 ◦C (decomp.); IR
(CH2Cl2) m(CO) 2053 (m), 2028 (m), 1994 (s), 1974 (m), 1948
(vs) cm−1; m(CN) 2116 (w) cm−1; 1H NMR (CD3COCD3) d 7.98–
7.37 (m, 9H, p-C6H5C6H4), 6.38 (t, 1H, C9H8, J = 3.0), 5.73 (t,
1H, C9H8, J = 6.3), 4.99 (dd, 1H, C9H8, J = 0.6, 1.8), 4.06–4.03
(m, 2H, C9H8), 3.40 (d, 1H, C9H8, J = 9.0), 2.96 (t, 1H, C9H8,
J = 1.2), 2.89 (t, 1H, C9H8, J = 2.1); MS m/z 393 [M+ − 4CO −
Cr(CO)5CN], 228 [M+ − 4CO − C(C6H5C6H4)NCCr(CO)5], 172
◦
in 50 mL of THF at −80 C was added 0.040 g (0.25 mmol) of
NaSC6H4CH3-p. The mixture turned from brick turbid solution
to deep red solution gradually. After stirring at −80 to −40 ◦C
for 3 h. The solvent was removed in vacuo at −40 ◦C and the
residue was chromatographed on an Al2O3 column at −25 ◦C
with petroleum ether–CH2Cl2 (5 : 1) as the eluent. A brown–red
4350 | Dalton Trans., 2006, 4348–4358
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[M+ − 4CO − Fe − C(C6H5C6H4)NCCr(CO)5]. Anal. Calc. for
C32H17O9NCrFe2: C, 53.15; H, 2.37; N, 1.94. Found: C, 53.09; H,
2.68; N, 1.88%.
for C32H17O9NCWFe2·0.5C6H14 (hexane): C, 46.81; H, 2.69; N,
1.56. Found: C, 46.64; H, 2.52; N, 1.95%.
Transformation of 10 into
[Fe(CO)2(g5-C9H8)C(C6H5)NCCr(CO)5] (16)
[Fe2{l-C(C6H5)NCMo(CO)5}(CO)4(g4,g4-C9H8)] (12)
A solution of 10 (0.250 g, 0.39 mmol) in 20 mL of CH2Cl2was
stirred at room temperature for 12 h, during this time the red
solution gradually turned yellow turbid solution. The solvent was
removed in vacuo and the residue was chromatographed on Al2O3
with petroleum ether–CH2Cl2 (10 : 1) as the eluent. The yellow
band was collected. After removal of the solvent, the residue was
recrystallized from petroleum ether–CH2Cl2 at −80 ◦C to give
0.066 g (32%) of yellow crystalline 16: mp 114–116 ◦C (decomp.);
IR (CH2Cl2) m(CO) 2060 (m), 2018 (s), 1970 (w), 1946 (vs, br) cm−1;
Brown–red crystals (71% yield); mp 44–46 ◦C (decomp.); IR
(CH2Cl2) m(CO) 2056 (m), 2029 (m), 1994 (s), 1975 (m), 1950 (vs,
1
br) cm−1; m(CN) 2114 (w) cm−1; H NMR (CD3COCD3) d 7.91–
7.25 (m, 5H, C6H5), 6.38 (t, 1H, C9H8, J = 2.7), 5.73 (t, 1H, C9H8,
J = 5.7), 4.98 (s, 1H, C9H8), 4.04–4.00 (m, 2H, C9H8), 3.40 (d, 1H,
C9H8, J = 9.6), 2.94 (t, 1H, C9H8, J = 1.2), 2.88 (m, 1H, C9H8);
MS m/z 373 [M+ − 2CO − Mo(CO)5CN], 317 [M+ − 4CO −
Mo(CO)5CN], 240 [M+ − 4CO − C(C6H5)NC − Mo(CO)5 −
+
C6H5], 116 (C9H8 ). Anal. Calc. for C26H13O9NMoFe2: C, 45.19;
1
m(CN) 2138 (w) cm−1; H NMR (CD3COCD3) d 7.51–7.09 (m,
H, 1.90; N, 2.03. Found: C, 45.05; H, 2.01; N, 2.06%.
5H, C6H5), 6.80 (dd, 1H, C9H8, J = 2.7, 10.8), 5.69 (d, 1H,
C9H8, J = 1.5), 5.52 (s, 2H, C9H8), 4.60 (dd, 1H, C9H8, J =
1.2, 3.9), 3.36 (m, 1H, C9H8), 2.90 (m, 1H, C9H8,), 1.96 (d, 1H,
C9H8, J = 6.9), 1.18–1.11 (m, 4H, CH3(CH2)4CH3), 0.86 (t, 3H,
CH3(CH2)4CH3); 13C NMR (CD3COCD3) d 218.6, 216.3, 214.1
(CO), 149.4, 137.1, 129.6, 123.7, 121.6 (C6H5), 91.5, 88.2, 85.6,
78.1, 76.9, 63.5, 57.0, 38.3 (C9H8); MS m/z 367 [M+ − 2CO −
Fe(CO)2], 317 [M+ − Cr(CO)5CN], 289 [M+ − CO − Cr(CO)5CN],
261 [M+ − 2CO − Cr(CO)5CN], 86 (C6H14+). Anal. Calc. for
C24H13O7NCrFe·0.5C6H14 (hexane): C, 56.08; H, 3.48; N, 2.42.
Found: C, 56.61; H, 3.11; N, 2.27%.
[Fe2{l-C(C6H4C6H5-p)NCMo(CO)5}(CO)4(g4,g4-C9H8)] (13)
Brown–red crystals (78% yield); mp 82–84 ◦C (decomp.); IR
(CH2Cl2) m(CO) 2056 (m), 2029 (m), 1994 (s), 1975 (m), 1951 (vs,
1
br) cm−1; m(CN) 2114 (w) cm−1; H NMR (CD3COCD3) d 7.98–
7.37 (m, 9H, C6H5C6H4-p), 6.40 (t, 1H, C9H8, J = 3.3), 5.75 (t,
1H, C9H8, J = 6.9), 5.00 (d, 1H, C9H8, J = 0.9), 4.07–4.01 (m, 2H,
C9H8), 3.40 (d, 1H, C9H8, J = 9.3), 2.97 (t, 1H, C9H8, J = 1.5), 2.92
(m, 1H, C9H8), 1.16–1.10 (m, 4H, CH3(CH2)4CH3), 0.85 (t, 3H,
CH3(CH2)4CH3); MS m/z 412 [M+ − 3CO − Mo(CO)5CN], 384
[M+ − 4CO − Mo(CO)5CN], 231 [M+ − 4CO − Mo(CO)5CN −
C6H5C6H4], 219 [M+ − 4CO − C(C6H5C6H4)NCMo(CO)5], 86
(C6H14+). Anal. Calc. for C32H17O9NMoFe2·0.5C6H14 (hexane):
C, 51.53; H, 2.99; N, 1.83. Found: C, 51.75; H, 2.78; N,
1.86%.
The following complexes were obtained by similar transforma-
tion.
[Fe(CO)2(g5-C9H8)C(C6H4C6H5-p)NCCr(CO)5] (17)
Yellow crystals (36% yield); mp 70–72 ◦C (decomp.); IR (CH2Cl2)
m(CO) 2060 (m), 2018 (s), 1971 (w), 1946 (vs, br) cm−1; m(CN)
1
2138 (w) cm−1; H NMR (CD3COCD3) d 7.40–6.98 (m, 9H, p-
[Fe2{l-C(C6H5)NCW(CO)5}(CO)4(g4,g4-C9H8)] (14)
C6H5C6H4), 6.80 (d, 2H, C9H8, J = 2.7), 5.69 (dd, 1H, C9H8, J =
0.9, 1.5), 5.52 (t, 1H, C9H8, J = 0.6), 4.60 (dd, 1H, C9H8, J = 1.2,
3.0), 3.36 (m, 1H, C9H8), 2.86 (d, 1H, C9H8, J = 1.5), 1.96 (d, 1H,
C9H8, J = 6.9), 1.20–1.12 (m, 4H, CH3(CH2)4CH3), 0.87 (t, 3H,
CH3(CH2)4CH3); 13C NMR (CD3COCD3) d 218.8, 216.2, 215.8,
214.3, 148.9, 137.0, 130.9, 123.0, 128.9, 128.1, 126.8, 123.6, 122.1,
121.6, 91.7, 88.3, 85.8, 84.6, 78.10, 75.4, 63.6, 57.1, 39.2; MS m/z
365 [M+ − CO − Cr(CO)5CN], 337 [M+ − 2CO − Cr(CO)5CN],
281 [M+ − Cr(CO)5CN − Fe(CO)2], 86 (C6H14+). Anal. Calc. for
C30H17O7NCrFe·0.5C6H14 (hexane): C, 60.58; H, 3.70; N, 2.14.
Found: C, 60.95; H, 3.44; N, 1.81%.
Brown–red crystals (63% yield); mp 100–102 ◦C (decomp.); IR
(CH2Cl2) m(CO) 2054 (m), 2029 (m), 1994 (s), 1975 (m), 1944 (vs,
1
br) cm−1; m(CN) 2116 (w) cm−1; H NMR (CD3COCD3) d 7.90–
7.25 (m, 5H, C6H5), 6.38 (t, 1H, C9H8, J = 3.0), 5.73 (t, 1H, C9H8,
J = 6.3), 4.99 (d, 1H, C9H8, J = 1.8), 4.05–4.00 (m, 2H, C9H8),
3.40 (d, 1H, C9H8, J = 6.3), 2.96 (t, 1H, C9H8, J = 1.8), 2.91 (m,
1H, C9H8); MS m/z 562 (M+ − 5CO − C6H5), 354 [M+ − CO −
W(CO)5CN], 326 [M+ − 2CO − W(CO)5CN], 298 [M+ − 3CO −
W(CO)5CN], 270 [M+ − 4CO − W(CO)5CN], 116 (C9H8 ). Anal.
+
Calc. for C26H13O9NWFe2: C, 40.09; H, 1.68; N, 1.80. Found: C,
39.82; H, 1.68; N, 1.85%.
[Fe(CO)2(g5-C9H8)C(C6H5)NCMo(CO)5] (18)
[Fe2{l-C(C6H4C6H5-p)NCW(CO)5}(CO)4(g4,g4-C9H8)] (15)
Yellow crystals (41% yield); mp 114–116 ◦C (decomp.); IR
Brown–red crystals (67% yield); mp 80–82 ◦C (decomp.); IR
(CH2Cl2) m(CO) 2054 (m), 2017 (m), 1994 (m), 1977 (w), 1933
(vs, br) cm−1; m(CN) 2117 (w) cm−1; 1H NMR (CD3COCD3)
d 7.97–7.35 (m, 5H, C6H5), 6.40 (t, 1H, C9H8, J = 2.7), 5.75
(t, 1H, C9H8, J = 5.4), 5.00 (s, 1H, C9H8), 4.07–4.02 (m, 2H,
C9H8), 3.41 (d, 1H, C9H8, J = 9.0), 2.98 (t, 1H, C9H8, J =
1.8), 2.91 (t, 1H, C9H8, J = 2.4), 1.12 (m, 4H, CH3(CH2)4CH3),
0.84 (t, 3H, CH3(CH2)4CH3); MS m/z 350 [M+ − W(CO)5CN −
C6H5C6H4], 294 [M+ − 2CO − W(CO)5CN − C6H5C6H4], 238
[M+ − 4CO − W(CO)5CN − C6H5C6H4], 86 (C6H14+). Anal. Calc.
(CH2Cl2) m(CO) 2064 (m), 2019 (s), 1980 (vs), 1948 (vs) cm−1;
1
m(CN) 2136 (w) cm−1; H NMR (CD3COCD3) d 7.40–7.10 (m,
5H, C6H5), 6.81 (d, 2H, C9H8, J = 2.4), 5.69 (s, 1H, C9H8), 5.61
(m, 2H, CH2Cl2), 5.53 (s, 1H, C9H8), 4.60 (t, 1H, C9H8, J = 2.7),
3.37 (dd, 1H, C9H8, J = 1.5, 2.1), 2.93 (d, 1H, C9H8, J = 1.8),
1.96 (d, 1H, C9H8, J = 6.6); 13C NMR (CD3COCD3) d 215.7,
215.4, 204.3 (CO), 146.6, 131.1, 128.5, 126.5, 123.4, 121.3 (C6H5),
94.4, 91.4, 87.9, 86.3, 85.5, 74.9, 66.2, 56.5, 42.3 (C9H8); MS m/z
317 [M+ − Mo(CO)5CN], 289 [M+ − CO − Mo(CO)5CN], 261
[M+ − 2CO − Mo(CO)5CN], 205 [M+ − Fe(CO)2 − Mo(CO)5CN],
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+
84 (CH2Cl2 ). Anal. Calc. for C24H13O7NMoFe·CH2Cl2: C,
on Al2O3 with petroleum ether–CH2Cl2 (10 : 1) as the eluent.
The orange band was eluted and collected. After removal of the
solvent, the residue was recrystallized from petroleum/CH2Cl2
at −80 ◦C to give 0.045 g (53%) of red crystals of 22: mp 92–
94 ◦C (decomp.); IR (CH2Cl2) m(CO) 2031 (s), 1987 (vs), 1964
(m), 1938 (w) cm−1; 1H NMR (CD3COCD3) d 7.73–7.30 (m,
9H, p-C6H5C6H4), 5.63 (m, 2H, C9H8 + CH2Cl2), 5.14–5.06 (m,
2H, C9H8), 4.84 (d, 1H, C9H8, J = 3.6), 4.29 (s, 1H, C9H8),
3.64 (t, 1H, C9H8, J = 6.0), 3.18 (m, 1H, C9H8), 2.48 (d, 2H,
OCH2CH3, J = 3.6, 11.1), 1.62 (d, 1H, C9H8, J = 7.8), 1.01 (t,
3H, OCH2CH3, J = 7.2); 13C NMR (CD3COCD3) d 220.7, 216.8,
206.4 (CO), 153.9, 141.2, 136.9, 129.4, 127.5, 127.0 (C6H5C6H4-
p), 91.9, 86.3, 82.3, 78.7, 73.2, 68.2, 61.7, 46.3, 35.1 (C9H8),
45.22; H, 2.28; N, 2.11. Found: C, 45.13; H, 2.05; N,
2.14%.
[Fe(CO)2(g5-C9H8)C(C6H4C6H5-p)NCMo(CO)5] (19)
Yellow crystals (30% yield); mp 52–54 ◦C (decomp.); IR (CH2Cl2)
m(CO) 2064 (m), 2019 (s), 1971 (w), 1948 (vs, br) cm−1; m(CN)
2136 (w) cm−1; H NMR (CD3COCD3) d 7.69–7.36 (m, 9H, p-
1
C6H5C6H4), 6.84 (d, 2H, C9H8, J = 2.4), 5.73 (s, 1H, C9H8), 5.55
(s, 1H, C9H8), 4.61 (t, 1H, C9H8, J = 2.4), 3.41 (s, 1H, C9H8), 2.89
(d, 1H, C9H8, J = 1.5), 1.98 (d, 1H, C9H8, J = 6.6); 13C NMR
(CD3COCD3) d 215.7, 214.0, 204.2 (CO), 147.5, 140.2, 138.8,
136.6, 129.1, 127.5, 126.8, 123.9, 121.7, 121.4 (p-C6H5C6H4), 94.4,
91.5, 88.0, 85.6, 83.0, 77.9, 75.0, 56.6, 47.4 (C9H8); MS m/z 365
[M+ − CO − Mo(CO)5CN], 337 [M+ − 2CO − Mo(CO)5CN],
184 [M+ − 2CO − Mo(CO)5CN − C6H5C6H4]. Anal. Calc. for
C30H17O7NMoFe: C, 54.99; H, 2.62; N, 2.14. Found: C, 55.66; H,
2.98; N, 2.26%.
20.7, 14.7 (OCH2CH3); MS m/z 353 [M+ − 2CO − C2H5
−
Fe(CO)3], 337 [M+ − 2CO − Fe (CO)3 − OC2H5], 184 [M+
−
+
2CO − Fe(CO)3 − OC2H5 − C6H5C6H4], 84 (CH2Cl2 ). Anal. Calc.
for C29H22O6Fe2·CH2Cl2: C, 54.34; H, 3.65. Found: C, 54.38; H,
3.82%.
[Fe(CO)2(g5-C9H8)C(C6H5)NCW(CO)5] (20)
X-Ray crystal structure determinations of complexes 2, 6, 8, 14, 18
and 22
Yellow crystals (37% yield); mp 138–140 ◦C (decomp.); IR
(CH2Cl2) m(CO) 2062 (m), 2019 (s), 1971 (w), 1942 (vs, br) cm−1;
The single crystals of complexes 2, 6, 8, 14, 18 and 22 suitable for
X-ray diffraction studies were obtained by recrystallization from
petroleum ether–CH2Cl2 at −80 ◦C. Single crystals were mounted
on a glass fibre and sealed with epoxy glue. The X-ray diffraction
intensity data for the six complexes were collected with a Bruker
Smart diffractometer at 20 ◦C using Mo-Ka radiation with an
x–2h scan mode.
The structures of 2, 6, 8, 14, 18 and 22 were solved by the
direct methods and expanded using Fourier techniques. For the six
complexes, the non-hydrogen atoms were refined anisotropically
and the hydrogen atoms were included but not refined. The
absorption corrections were applied using SADABS. The final
cycle of full-matrix least-squares refinement was based on the
observed reflections and the variable parameters and converged
with unweighted and weighted agreement to give the agreement
factors listing in Table 1.
The details of the crystallographic data and the procedures used
for data collection and reduction information for 2, 6, 8, 14, 18
and 22 are given in Table 1. The molecular structures of 2, 6, 8,
14, 18 and 22 are given in Fig. 1–6, respectively.
CCDC reference numbers 608256–608261.
For crystallographic data in CIF or other electronic format see
DOI: 10.1039/b607283f
1
m(CN) 2138 (w) cm−1; H NMR (CD3COCD3) d 7.39–6.99 (m,
5H, C6H5), 6.80 (d, 2H, C9H8, J = 2.4), 5.68 (s, 1H, C9H8),
5.52 (s, 1H, 6.56, C9H8), 4.59 (d, 2H, C9H8, J = 0.6), 3.25
(d, 1H, C9H8, J = 1.5), 2.88 (m, 1H, C9H8), 1.95 (d, 1H,
C9H8, J = 6.9); 13C NMR (CD3COCD3) d 216.3, 214.4, 195.3
(CO), 148.9, 143.9, 137.2, 130.2, 129.2, 128.4, 126.6, 124.0, 121.8
(C6H5), 94.2, 88.6, 86.3, 84.9, 78.4, 75.6, 63.9, 57.1, 39.5 (C9H8);
MS m/z 585 (M+ − 3CO), 501 [M+ − 2CO − Fe(CO)2], 263
[M+ − 2CO − W(CO)5CN]. Anal. Calc. for C24H13O7NWFe:
C, 43.21; H, 1.96; N, 2.10. Found: C, 42.99; H, 2.11; N,
2.03%.
[Fe(CO)2(g5-C9H8)C(C6H4C6H5-p)NCW(CO)5] (21)
Yellow crystals (29% yield); mp 44–46 ◦C (decomp.); IR (CH2Cl2)
m(CO) 2062 (m), 2019 (s), 1972 (w), 1942 (vs, br) cm−1; m(CN)
1
2138 (w) cm−1; H NMR (CD3COCD3) d 7.66–7.31 (m, 9H, p-
C6H5C6H4), 6.84 (d, 2H, C9H8, J = 2.4), 5.73 (d, 1H, C9H8, J =
1.2), 5.57 (d, 1H, C9H8, J = 0.6), 4.62 (t, 1H, C9H8, J = 3.0), 3.42
(m, 1H, C9H8), 2.90 (dd, 1H, C9H8, J = 5.1, 9.0), 1.98 (d, 1H,
C9H8, J = 6.9), 1.20–1.12 (m, 4H, CH3(CH2)4CH3), 0.86 (t, 3H,
CH3(CH2)4CH3); 13C NMR (CD3COCD3) d 213.6, 213.0, 194.7
(CO), 148.1, 146.7, 142.2, 133.9, 129.0, 126.8, 126.7 (p-C6H5C6H4),
95.3, 93.9, 90.5, 85.6, 78.5, 74.6, 69.0, 50.9, 45.7 (C9H8); MS
m/z 337 [M+ − 2CO − W(CO)5CN], 281 [M+ − W(CO)5CN −
Fe(CO)2], 86 (C6H14+). Anal. Calc. for C30H17O7NWFe·0.5C6H14
(hexane): C, 50.41; H, 3.07; N, 1.78. Found: C, 50.22; H, 2.69; N,
1.77%.
Results and discussion
3
5
Pentacarbonyl-7H-indenediiron, [Fe2(CO)5(g ,g -C9H8)] (1), re-
acts with about 20% molar excess of the aryllithium reagents,
ArLi (Ar = C6H5, p-C6H5C6H4), in ether at low temperature (−60
to −30 ◦C) for 3 h followed by alkylation with Et3OBF4. After
removal of the solvent under high vacuum at low temperature,
the residue was worked up as described in the Experimen-
tal Section to afford the 7H-indene-coordinated diiron bridg-
Transformation of 3 into [Fe2{C(OC2H5)C6H4C6H5-
p(g2,g5-C9H8)}(CO)5] (22)
A CH2Cl2 solution (20 mL) of 3 (0.080 g, 0.15 mmol) in a closed
Schlenk flask was stirred at room temperature for 12 h, during
which time the deep red solution turned orange. The solvent
was removed in vacuo and the residue was chromato-graphed
4
4
ing alkoxycarbene complexes [Fe2{l-C(OC2H5)Ar}(CO)4(g ,g -
C9H8)] (2, Ar = C6H5; 3, Ar = p-C6H5C6H4) (eqn (1)) in 79–86%
yields.
4352 | Dalton Trans., 2006, 4348–4358
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Table 1 Crystal data and experimental details for complexes 2, 6, 8, 14, 18 and 22
2·0.5CH2Cl2
6
8
14
18
22·CH2Cl2
Formula
Mr
C22.5H19O5ClFe2
516.53
C2/c (15)
20.8199(16)
16.9844(13)
14.2447(11)
C20H14O4Fe2
430.01
P21/n (14)
9.2338(14)
16.086(3)
11.8502(18)
C27H20O4SFe2
552.19
P1 (2)
C26H13O9NFe2W C24H13O7NFeMo C30H24O6Cl2Fe2
778.92
579.14
Pca21 (29)
30.716(3)
7.2926(6)
21.0737(18)
90
90
90
4720.4(7)
8
663.09
P1 (2)
¯
¯
Space group (no.)
P21/n (14)
8.2775(6)
16.1260(11)
20.0995(14)
˚
a/A
9.1797(10)
9.5684(10)
14.1755(15)
86.611(2)
80.660(2)
75.326(2)
1188.3(2)
2
1.543
564
13.41
1069
4.401–39.176
2.92–54.00
5052
2489
308
8.1399(7)
10.3465(9)
17.0935(15)
86.069(2)
80.494(2)
89.464(2)
1416.5(2)
2
˚
b/A
˚
c/A
a/◦
b/◦
c /◦
116.1330(10)
97.343(3)
92.648(2)
3
˚
V/A
4522.2(6)
8
1.517
2104
14.31
1745.8(5)
4
1.636
872
16.84
2680.1(3)
4
Z
Dc/g cm−3
1.930
1496
1.630
2304
1.555
676
F(000)
l(Mo-Ka)/cm−1
No. orientation refl.
Orientation range 2h/◦
Data coll. range, 2h/◦
No. unique data, total
with I > 2.00r(I)
No. params. refined
54.03
2808
11.90
4114
12.55
1675
2659
899
5.173–48.278
3.24–54.00
4922
3470
269
5.278–34.567
4.30–54.00
3793
1934
235
4.780–47.548
3.24–54.00
5820
4.688–43.946
2.66–54.00
9080
4.488–44.513
3.84–54.00
6017
4012
5328
3451
352
638
374
Correct. factors, max. min. 0.75523–1.00000
0.86201–1.00000 0.75892–1.00000 0.75440–1.00000 0.80535–1.00000 0.84868–1.00000
Ra
Rw
Sc
0.0556
0.1424
1.007
0.001
1.048
0.0565
0.0782
0.809
0.0503
0.0905
0.772
0.0608
0.1250
0.987
0.0471
0.0746
0842
0.0509
0.1069
0.771
b
Max. shift/esd. final cycle
Largest peak/e A
Minimum peak/e A
0.000
0.000
0.001
0.092
0.059
−3
˚
0.571
0.482
1.743
0.617
0.713
−3
˚
−0.508
−0.345
−0.361
−1.643
−0.284
−0.444
ꢀ
ꢀ
ꢀ
ꢀ
ꢀ
a R = ||Fo| − |Fc||/ |Fo|. b Rw = [ w(|Fo| − |Fc|)2/ w|Fo|2]1/2; w = 1/r2(|Fo|). c Quality-of-fit, S = [ w(|Fo| − |Fc|)2/(Nobs − Nparameters)]1/2
.
(1)
Complexes 2 and 3 are soluble both in polar organic and
nonpolar solvents. They are very sensitive to air and temperature
in solution but relatively stable as the solid. The IR spectra of
complexes 2 and 3 showed four CO absorption bands at ca.
2019, 1973, 1951 and 1911 cm−1 in the m(CO) region, evidence an
1
Fe2(CO)4 moiety in both complexes. The H and 13C NMR data
for 2 and 3 were not obtained or assigned due to easy conversion
or the broadened signals for the 7H-indene ligand bridged by
the diiron center. The further characterization for their structures
was obtained by X-ray analysis of 2, which firmly confirmed the
proposed structure for products 2 and 3 shown in eqn (1) and
indicated that one terminal CO ligand of compound 1 has been
converted into a bridging carbene ligand upon the reaction of
1 with nucleophilic aryllithium and subsequent alkylation with
Et3OBF4.
Fig. 1 Molecular structure of 2, showing the atom-numbering scheme
with 45% thermal ellipsoids.
crystallographic data on 2. First, the Fe–Fe bond length is
16b
˚
˚
quite shorter, 2.6663(8) A, as compared with that (2.782(1) A
of starting compound 1. A short Fe–Fe bond, arising from
the bridge of l-carbene ligand, is characteristic for this
A drawing of the molecular structure of 2 appears as Fig. 1.
There are three important observations to be made from the
8
type of molecule; [Fe2{l-C(OEt)C6H4CF3-p}(CO)4(g -C8H8)] and
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5
[Fe2(l-CO){l-C(OEt)C6H5}(CO)2(g -C5H5)2] have Fe–Fe bond
8
lengths of 2.686(1)7 and 2.512(1) A, respectively. Second, the
˚
six-membered ring of the 7H-indene ligand is distorted away
from planarity due to the methylene carbon atom (C(14)). The
other five atoms in the ring, C(6) and C(10) through C(13), are
roughly coplanar. Third, the coordination mode of 7H-indene
ligand in 2 is essentially the same as that for compound 1,
even though the presence of some bonding interaction should
be taken into account between Fe(1) and C(10), whose distance at
(2)
˚
2.476(4) A is considerably longer than the other Fe–C distances
˚
associated with 7H-indene ligand (Fe(1)–C(13) 2.202(4) A, Fe(1)–
˚
˚
C(12) 2.062(4) A, Fe(1)–C(11) 2.116(4) A), this may be explained
by the existence of the contribution of the rare structure B toward
the predominant structure A shown below.Both structures consist
The cationic carbyne complexes 4 and 5 would be the 7H-
indene-coordinated dimetal complexes with a bridging carbyne
ligand as inferred from its reactivity (below) and previously
reported analogous complexes,13a,23 as well as their 1H NMR and
IR spectra. Complexes 4 and 5 are only sparingly soluble in polar
organic solvents such as THF and CH2Cl2 and very sensitive to air,
moisture and temperature and can be stored at low temperatures
(below −60 ◦C) only for a short period of time. The carbyne
structure is just a plausible proposal for both complexes, which
are prepared in situ and not fully characterized.
The freshly prepared (in situ) diiron cationic carbyne complexes
4 and 5 react with NaBH4 in THF at −80 to −40 ◦C for 3 h. After
work-up as described in the Experimental section, arylcarbene
4
4
complexes [Fe2{l-C(H)Ar}(CO)4(g ,g -C9H8)] (6, Ar = C6H5;
7, Ar = p-C6H5C6H4) were obtained in 73–85% isolated yields
(eqn (3)).
of 18e–18e diiron centers. Thus, in 2 the 7H-indene ligand is better
4
4
to describe as an g ,g -bonding coordinated to Fe(1) and Fe(2)
(structure A), which is an interesting ring variation similar to the
4
4
COT g ,g systems.7
The reaction pathway to complexes 2 and 3 shown in eqn (1) is
similar to that of the reactions of the cycloheptatriene-coordinated
hexacarbonyldiiron compound [C7H8Fe2(CO)6] with aryllithium
reagents.10 The Ar− anion firstly attacks on a CO ligand of
Fe(CO)3 moiety of 1 to form an acylmetalate intermediate (a).
This is a favorable attack since the electron density on a CO
ligand in Fe(CO)3 moiety is lower than that in Fe(CO)2 moiety.
The intermediate (a) can be converted into the intermediate
(b),22 which was subsequently alkylated with Et3OBF4 to afford
bridging alkoxycarbene complex 2 or 3 (eqn (1)). It is strange
that the other aryllithium reagents, such as o-, m-, p-CH3C6H4Li,
p-CH3OC6H4Li and p-CF3C6H4Li in which the aryl groups
contain either an electron-pushing or an electron-withdrawing
group, do not react with compound 1 to give the analogous
bridging alkoxycarbene complexes. This could be arising from
the lability of intermediates (a) or (b) formed from 1 and
these aryllithiums due to electron effect of the aryl substituents,
which occurred decomposition upon alkylation with Et3OBF4
in aqueous solution. To our knowledge, products 2 and 3 are
the first examples of the dimetal bridging carbene complexes
derived from a dimetal compound bearing only terminal CO
ligands.
(3)
The proposed structures for 6 and 7 were first supported by
microanalytic and spectroscopic data. Their 1H NMR spectra have
a resonance at ca. 7.08–7.09 ppm for a l-CHAr group. However,
this resonance has undergone obviously upfield shift, as compared
to that of analogous COT-coordinated bridging arylcarbene
complex [Fe2{l-C(H)C6H4CF3-p}(CO)4(g -C8H8)] (d 9.17).13a This
8
probably is arising from that the H atom is influenced by the ring
current of the 7H-indene moiety. The further characterization
for their structures was obtained by an X-ray diffraction study
of 6.
The structure of 6 (Fig. 2) is similar to that of 2, except that
OC2H5 group on the l-carbene carbon in 2 is replaced by a H
atom in 6. Many structural features of 6 are nearly the same as
those in 2.
The cationic carbyne complexes 4 and 5 react similarly with
NaSC6H4CH3-p to afford diiron bridging arylthiocarbene com-
The bridging alkoxycarbene complexes 2 and 3 in ether was
treated (eqn (2)) with an excess of HBF4·Et2O at low temperature
(−60 to −30 ◦C) for 1 h to give 7H-indene-coordinated diiron
4
4
cationic bridging carbyne complexes [Fe2(l-CAr)(CO)4(g ,g –
C9H8)]BF4 (4, Ar = C6H5; 5, Ar = p-C6H5C6H4) as brick red
solids in 90–95% yields.
4
4
plexes [Fe2{l-C(Ar)SC6H4CH3-p}(CO)4(g ,g -C9H8)] (8, Ar =
C6H5; 9, Ar = p-C6H5C6H4) (eqn (4)) in 71–87% yields,
4354 | Dalton Trans., 2006, 4348–4358
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Fig. 3 Molecular structure of 8, showing the atom-numbering scheme
with 40% thermal ellipsoids.
iron bridging aryl(pentacarbonylcyanometal)–carbene complexes
4
4
Fig. 2 Molecular structure of 6, showing the atom-numbering scheme
with 45% thermal ellipsoids.
[Fe2{l-C(Ar)NCM(CO)5}(CO)4(g ,g -C9H8)] (10–15) (eqn (5)) in
63–78% isolated yield.
of which the structure of 8 has been established by X-ray
analysis.
(5)
(4)
Complexes 10–15 are sensitive to air and temperature in both
solution and the solid state. The spectroscopic data of complexes
10–15 are consistent with their structures shown in eqn (5). The IR
spectra of 10–15 in the m(CO) region showed five absorption bands
of the CO groups at 2056–1944 cm−1. The characteristic m(CN)
stretching vibration occurs at ca. 2114–2116 cm−1, similar to those
The IR spectra of products 8 and 9 exhibit four absorp-
tion bands (at ca. 2017–218, 1981–1982, 1960–1961 and 1922–
1939 cm−1) in the m(CO) region with a pattern similar to that
of bridging alkoxycarbene complexes 2 and 3. The site of nucle-
ophilic attack of NaSC6H4CH3-p resembles the reactions11,12a,15
of cationic bridging carbyne complexes [Fe2(l-CO)(l-CAr)-
8
of analogous complex [Fe2{l-C(Ar)NCM(CO)5}(CO)4(g -C8H8)]
5
5
(CO)2(g -C5H5)2]BBr4 and [Fe2(l-CO)(l-CAr)(CO)2{(g -C5H4)2-
Si(CH3)2}]BBr4 with NaSR, which resulted in nucleophilic addi-
tion to the l-carbyne carbon to give corresponding diiron bridging
arylthiocarbene complexes.
(at ca. 2117–2125 cm−1).13a The 1H NMR data for compounds 10–
15 showed the proton signals attributed to the 7H-indene ligand
at 6.40–2.86 ppm which are downfield of those in 6 and 7 (at 5.97–
2.63 ppm) because of the stronger electron-accepting ability of
(CO)5MCN as compared with H group. The proposed structures
for 10–15 are eventually confirmed by an X-ray diffraction study
of 14.
The molecular structure of complex 8 (Fig. 3) is fundamentally
the same as that of 2, except that the substituent on the l-carbene
carbon is a p-CH3C6H4S group in 8 but an OC2H5 group in the
˚
latter. The distance of the Fe–Fe bond in 8 is 2.6754(8) A, very
Complex 14 has a structure (Fig. 4) in which a W(CO)5CN
group is bound to the l-carbene carbon through the N atom.
The structural features of the principal portion of [Fe2(l-
CC6H5)(CO)4(g ,g -C9H8)] of 14 are very similar to those of the
same unit in 2 and 8. The interesting structure of 14 is the l-
C(C6H5)W(CO)5CN ligand, in which the two C–N bond lengths
close to that in 2 and 6. The l-carbene carbon approximately
symmetrically bridges the Fe–Fe bond with a C(5)–Fe(1) of
1.984(4) A and a C(5)–Fe(2) of 2.103(4) A distances. The C(5)–S
4
4
˚
˚
˚
bond length of 1.801(4) A in 8 indicates that it is essentially single
bond by comparison with standard C(sp )–S (1.76 A)24 single bond
2
˚
3
24
˚
˚
and C(sp )–S (1.81 A) single bond distances.
are very different. C(15)–N(1) has a bond length of 1.160(10) A,
Complexes 4 and 5 can also react with anionic carbonylmetal
compound containing a CN negative substituent, Na[M(CO)5-
(CN)] (M = Cr, Mo, W), to afford 7H-indene-coordinated di-
which indicates high triple-bond character and is essentially the
same as the corresponding distance in analogous complex [Fe2{l-
8
13a
˚
C(C6H4CF3-p)NCW(CO)5}(CO)4(g -C8H8)] (1.174(13) A). The
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The conversions of products 10–15 into complexes 16–21 were
initially revealed by their 1H NMR spectra. The acetone-d6
solution of 10 or 11–15 whose NMR spectrum had been measured
was kept at room temperature for about 1–2 h, during which time
1
the solution changed from deep red to yellow. Their H NMR
spectra now showed only the proton signals attributable to the
7H-indene ring and aryl group of 16 or 17–21. Further evidence
for this conversion came from the isolation of crystals of 16–21
from the CH2Cl2 solution shown in eqn (6).
Complexes 16–21 were the corresponding decomposition prod-
ucts of 10–15. The Fe(CO)2 moiety coordinated to the six-
membered ring of the 7H-indene ligand in 10–15 was lost and
the original l-carbene ligand became a C(Ar)NCM(CO)5 group
bonded to Fe(2) and a carbon atom (C(13)) of the six-membered
ring through l-carbene carbon (C(5)) in 16–21.
The molecular structure of 18 (Fig. 5) shows that the config-
uration and bond distances of the 7H-indene ligand have been
changed by comparison with analogous parent 14, caused by the
loss of the Fe(CO)2 moiety and the transfer of the carbene ligand
C(Ar)NCMo(CO)5 from the lost Fe(1) atom to the C(13) atom
of the indene ring. In the six-membered ring moiety, only C(10),
˚
C(11), C(12) and C(13) are in a plane ( 0.0023 A); C(14) is out of
Fig. 4 Molecular structure of 14, showing the atom-numbering scheme
with 45% thermal ellipsoids.
˚
the C(10)C(11)C(12)C(13) plane by 1.0912 A.
˚
other is C(5)–N(1) with the bond length of 1.404(10) A, which is
=
between the normal C–N and C N distances and slightly shorter
than the corresponding C–N distance in [Fe2{l-C(C6H4CF3-
8
13a
˚
p)-NCW(CO)5}(CO)4(g -C8H8)] (1.412(13) A).
The shorter
˚
W–C(15) distance of 2.139(9) A in 14 signifies its high double
bond character. The C(5), N(1), C(15) and W atoms are coplanar
with a C(5)–N(1)–C(15) angle of 175.4(8)◦ and a N(1)–C(15)–W
angle of 176.4(7)◦, indicating that C(5)–N(1)–C(15)–W fragment
is almost linear.
The reaction pathway to complexes 10–15 could proceed via
−
= =
attack of the (CO)5M C N (M = Cr, Mo, W) anion, a repre-
sentation of the same electronic structure of the −M(CO)5(CN)
anion, on the l-carbyne carbon of cationic 4 or 5 to produce the
product.
Interestingly, when the solution of products 10–15 in CH2Cl2
was stirred at room temperature for 12 h, the deep red so-
lution gradually turned yellow. After workup as described in
the Experimental section, the isomerized 7H-indene-coordinated
Fig. 5 Molecular structure of 18, showing the atom-numbering scheme
with 45% thermal ellipsoids.
5
monoiron complexes with a C(Ar)NCM(CO)5 group, [Fe(CO)2(g -
C9H8)C(Ar)NCM(CO)5] (16–21), were obtained in lower (29–
41%) yields (eqn (6)), of which the structure of 18 has been
established by X-ray crystallography.
In contrast to the nearly equal distances in C(10) to C(13) of
˚
the C6 ring in 14, in 18 the C(10)–C(11) (1.445(12) A) and C(12)–
˚
C(13) (1.492(12) A) bonds are much longer than C(11)–C(12)
˚
(1.287(12) A), indicating that the latter is a double-bond. The
structure of the Mo(CO)5CN moiety in 18 are the same as those
in 14. An only difference for the Mo(CO)5CN moiety in 14 and
18 is the larger C(5)–N(1)–C(15) (179.7(8)◦) and N(1)–C(15)–Mo
(178.0(7)◦) bond angles in 18, indicating an highly linear for the
C(5)–N(1)–C(15)–W fragment.
(6)
Likewise interestingly, a CH2Cl2 solution of bridging alkoxy-
carbene complex 3 in a closed flask was stirred at room
temperature for 12 h to give a novel ring addition product
2
5
[Fe2{C(OC2H5)C6H4C6H5-p-(g ,g -C9H8)}(CO)5] (22) in 53% yield
4356 | Dalton Trans., 2006, 4348–4358
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Fig. 6 Molecular structure of 22, showing the atom-numbering scheme with 45% thermal ellipsoids.
(eqn (7)), whose structure has been established by its X-ray
analysis.
were synthesized from pentacarbonyl-7H-indenediiron, a diiron
compound bearing only terminal CO ligands and a series of novel
7H-indene-coordinated bridging carbene complexes have been
obtained by reactions of their cationic bridging carbyne complexes
with the nucleophiles involving carbonylmetal anions. This opens
up a new route to synthesize dimetal bridging carbene complexes
and provides an useful and convenient method for the preparation
and structural modification of such bridging carbene complexes.
The unusual transformation of complexes 3 and 10–15 have also
been investigated. Further studies on the scope of the reaction and
application in organic and organometallic synthesis are now being
carried out in our laboratory.
(7)
The transformation of complex 3 into complex 22 was initially
revealed by its IR spectrum. The CH2Cl2 solution of 3 whose
IR spectrum had been recorded was kept at room temperature for
about 5–10 min, its IR spectrum now showed only four absorption
bands at 2031, 1987, 1964 and 1938 cm−1 attributable to 22.
Further evidence for this transformation came from its isolation
of crystalline 22 from the CH2Cl2 solution shown in eqn (7).
The crystallographic investigation of 22 reveals an unusual
structure (Fig. 6), which is quite different from that of 3, arising
from that the l-C–Fe(2) bond in 3 was cleaved and the l-carbene
carbon (C(5)) is linked to a ring carbon (C(13)) of the 7H-indene
Acknowledgements
We thank the National Natural Science Foundation of China, the
Science Foundation of the Chinese Academy of Sciences and the
JSPS of Japan for financial support of this research.
References
1 (a) F. G. A. Stone, in Advances in Metal Carbene Chemistry, ed. U. Schu-
bert, Kluwer Academic Publishers, Dordrecht, The Netherlands, 1989,
p. 11; (b) G. A. Carriedo, J. A. K. Howard and F. G. A. Stone, J. Chem.
Soc., Dalton Trans., 1984, 1555; (c) M. E. Garcia, J. C. Jeffery, P.
Sherwood and F. G. A. Stone, J. Chem. Soc., Dalton Trans., 1987,
1209; (d) D. Hodgson, J. A. K. Howard, F. G. A. Stone and M. J. Went,
J. Chem. Soc., Dalton Trans., 1985, 331; (e) M. U. Pilotti, F. G. A. Stone
and L. Topaloglu, J. Chem. Soc., Dalton Trans., 1991, 1621.
2 (a) J. B. Keister, M. W. Payne and M. J. Muscatella, Organometallics,
1983, 2, 219; (b) J. B. Keister, J. Chem. Soc., Chem. Commun., 1979,
214; (c) J. B. Keister, Polyhedron, 1988, 7, 847.
3 (a) L. Busetto and V. Zanotti, J. Organomet. Chem., 2005, 690,
5430; (b) L. Busetto, F. Marchetti, S. Zacchini and V. Zanotti,
Organometallics, 2005, 24, 2297; (c) V. G. Albano, L. Busetto, F.
Marchetti, M. Monari, S. Zacchini and V. Zanotti, Organometallics,
2004, 23, 3348.
4 (a) M. Akita, R. Hua, S. A. R. Knox, Y. Moro-oka, S. Nakanishi and
M. I. Yates, J. Organomet. Chem., 1998, 569, 71; (b) S. A. R. Knox,
J. Organomet. Chem., 1990, 250, 255; (c) R. E. Colborn, D. L. Davies,
A. F. Dyke, S. A. R. Knox, K. A. Mead, A. G. Orpen, J. E. Guerchais
and J. Roue, J. Chem. Soc., Dalton Trans., 1989, 1799.
5 (a) J. R. Matachek, R. J. Angelici, K. A. Schugart, K. J. Haller and
R. F. Fenske, Organometallics, 1984, 3, 1038; (b) M. H. Quick and
R. J. Angelici, Inorg. Chem., 1981, 20, 1123; (c) N. C. Schroeder, R.
Funchness, R. A. Jacobson and R. J. Angelici, Organometallics, 1989,
8, 521.
2
ligand leading to formation of an g -bonding to coordinate to
the Fe(CO)3 moiety in 22. Thus, the six-membered ring of the
7H-indene ligand carries a C(OC2H5)C6H5C6H4-p group on C(13)
and its configuration and bond lengths have been changed, similar
to that in 18, caused by the migration of the l-carbene ligand
C(OC2H5)C6H5C6H4-p from Fe(2) to C(13) of the C6 ring. In 22,
the ring carbons C(11) and C(12) are coordinated to Fe(1) in
2
an g -bonding and C(5) is r bound to Fe(2) and a CO group
generated from the decomposition of 3 or an intermediate is also
˚
coordinated to the Fe(1) atom. The Fe–Fe distance (2.752(7) A) is
˚
slightly longer than that (2.6663(8) A) of 2, a phenyl analogue of
3. The Fe(1)–C bond lengths of C(11) and C(12) are 2.217(4) and
˚
2.199(4) A, respectively. The structure of the six-membered ring
moiety of the 7H-indene ligand in 22 are similar to that in 18. An
apparent difference between 22 and 18 is the longer C(11)–C(12)
˚
bond distance (1.357(6) A) in 22 owing to the coordination of
Fe(1).
In summary, we have discovered the first examples of the dimetal
bridging carbene complexes derived from a dimetal compound
bearing only terminal CO ligands. A new type of the 7H-indene-
coordinated diiron bridging alkoxycarbene complexes 2 and 3
6 (a) D. Navarre, A. Parlier, H. Rudler and J. C. Daran, J. Organo-
met. Chem., 1987, 322, 103; (b) C. Alvarez-Toledano, A. Parlier,
This journal is
The Royal Society of Chemistry 2006
Dalton Trans., 2006, 4348–4358 | 4357
©

View Article Online
F. Rose-Munch, H. Rudler, J. C. Daran, C. Knobler and Y. Jeannin,
J. Organomet. Chem., 1987, 323, 371.
7 J.-B. Chen, D.-S. Li, Y. Yu, Z.-S. Jin, Q.-L. Zhou and G.-C. Wei,
Organometallics, 1993, 12, 3885.
8 J.-B. Chen, D.-S. Li, Y. Yu and C. G. Chen, Organometallics, 1994, 13,
3581.
9 R.-T. Wang, J. Sun and J.-B. Chen, J. Organomet. Chem., 2001, 617–618,
292.
16 (a) S. G. Davies, K. S. Holland, K. H. Sutton and J. P. McNally,
Isr. J. Chem., 1991, 31, 25; (b) F. A. Cotton and B. E. Hanson, Inorg.
Chem., 1977, 16, 1861.
17 E. E. Reid, Organic Chemistry of Bivalent Sulfur, Chemical Publishing
Co. Inc., New York, NY, 1958, vol. 1, p. 127.
18 R. B. King, Inorg. Chem., 1967, 6, 25.
19 G. Wittig, Angew. Chem., 1940, 53, 243.
20 H. Gilman, W. Langham and F. W. Moore, J. Am. Chem. Soc., 1940,
62, 2327.
21 H. Meerwein, G. Hinze, P. Hofmann, E. Kroniny and E. Pfeil, J. Prakt.
Chem., 1937, 147, 257.
10 Y. Yu, J.-B. Chen, J. Chen and P.-J. Zheng, Organometallics, 1993, 12,
4731.
11 Y.-J. Liu, R.-T. Wang, J. Sun and J.-B. Chen, Organometallics, 2000, 19,
3784.
22 According to the properties of di- or polymetal bridging carbene
complexes, the intermediates (a) and (b) could be converted to each
other, i.e. the monometal carbene ligand and dimetal bridging carbene
ligand can be converted to each other, accompanied by the conversion
between the terminal CO group and bridging CO group. For detailed
review on fluxional metal carbonyls, see: F. A. Cotton, Inorg. Chem.,
2002, 41, 643.
12 (a) R.-T. Wang, Q. Xu, J. Sun, Li-C. Song and J.-B. Chen,
Organometallics, 2001, 20, 4092; (b) R.-T. Wang, J. Sun, J.-B. Chen,
Q. Xu and Y. Souma, J. Organomet. Chem., 2002, 658, 214.
13 (a) S. Zhang, Q. Xu, J. Sun and J.-B. Chen, Organometallics, 2003, 22,
1816; (b) S. Zhang, Q. Xu, J. Sun and J.-B. Chen, Chem.–Eur. J., 2003,
9, 5111.
14 (a) P.-H. Wang, R.-H. Li, J. Sun and J.-B. Chen, Chem. Commun., 1998,
631; (b) Nu. Xiao, S. Zhang, Z.-L. Qiu, R.-H. Li, P.-H. Wang, Q. Xu,
J. Sun and J.-B. Chen, Organometallics, 2002, 21, 3709.
15 Y.-J. Liu, R.-T. Wang, J. Sun and J.-B. Chen, Organometallics, 2000, 19,
3498.
23 N. Xiao, Q. Xu, J. Sun and J.-B. Chen, Dalton Trans., 2005,
3250.
24 (a) B. Rozsondai, G. Schultz and I. Hargittai, J. Mol. Struct., 1981, 70,
309; (b) S. Samdal, H. M. Seip and T. Torgrimsen, J. Mol. Struct., 1979,
57, 105.
4358 | Dalton Trans., 2006, 4348–4358
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