Cyclopentadienyliron complexes of nitrosobenzene: Preparation, structure and reactivity with olefins

Article abstract of DOI:10.1016/j.jorganchem.2005.06.045

The preparation, characterization and reactivity of (η⁵- cyclopentadienyl)iron complexes of nitrosobenzene are investigated as potential intermediates in the [CpFe(CO)₂]₂ (1)-catalyzed allylic amination of olefins by nitro

Full text of DOI:10.1016/j.jorganchem.2005.06.045

Journal of Organometallic Chemistry 690 (2005) 4727–4733
www.elsevier.com/locate/jorganchem
Cyclopentadienyliron complexes of nitrosobenzene:
Preparation, structure and reactivity with olefins
*
Jeremy C. Stephens, Masood A. Khan, Kenneth M. Nicholas
Department of Chemistry and Biochemistry, University of Oklahoma, 620 Parrington Oval, Norman, OK 73019, United States
Received 8 June 2005; received in revised form 29 June 2005; accepted 29 June 2005
Available online 30 August 2005
Abstract
The preparation, characterization and reactivity of (g5-cyclopentadienyl)iron complexes of nitrosobenzene are investigated as
potential intermediates in the [CpFe(CO)2]2 (1)-catalyzed allylic amination of olefins by nitroarenes. The oxidation of 1 by [Cp2Fe]+
in the presence of PhNO produces a novel dinuclear complex {[CpFe-l-(g2-(N,O)-PhNO)]2-l-NHPh}BF4 (2) along with [CpFe-
(CO)3]BF4 and [CpFe(CO)2(NH2Ph)]BF4; 2 has been characterized spectroscopically and by X-ray diffraction. Reaction of
CpFe(CO)2I with PhNO and AgSbF6 produces the mononuclear complex [CpFe(CO)2(g2-PhNO)]SbF6 (3) which has also been
characterized spectroscopically, crystallographically and by PM3 MO calculations. The reaction of 3 with a-methyl styrene affords
[CpFe(CO)2(PhNH2)SbF6] and a trace of N-phenyl-2-phenylallyl amine 4, while the reaction of 3 with 2,3-dimethyl-1,3-butadiene
affords the aniline complex and a hetero-Diels-Alder adduct 5, indicative of PhNO dissociation. Together these results preclude the
involvement of nitrosoarene complex 3 as an important intermediate in the allylic amination catalyzed by [CpFe(CO)2]2.
ꢀ 2005 Elsevier B.V. All rights reserved.
Keywords: Nitrosoarene–iron complex; Allylic amination
1. Introduction
(CO)2]2-catalyzed allylic amination was also developed
which allows the reactions to be conducted in common
laboratory glassware [4]. Cenini and Ragaini have de-
scribed a Ru3(CO)12-diimine catalytic system for allylic
amination using nitroarenes as the aminating agent [5].
Mechanistic insight into these nitroarene reductive
processes is very limited, especially with respect to the
reactive nitrogen species involved. A few studies have
demonstrated the involvement of various metallacycles
incorporating RNO2 and CO in the deoxygenation pro-
cess [6–8]. Nitrenoid species, free or coordinated, have
often been presumed to be intermediates in these reac-
tions [1], but direct evidence for their involvement or
the intervention of other reactive intermediates in the
reactions is scarce. Trapping experiments, product isola-
tion and kinetics studies of the Fp-catalyzed allylic ami-
nation in our laboratory [2,9,10] have ruled out the
intervention of free nitrosoarenes or nitrenes as reaction
Transition metal-promoted reductions of nitroorgan-
ics by carbon monoxide have been widely investigated as
a means for the production of a variety of valuable orga-
nonitrogen compounds, including amines, isocyanates,
carbamates, ureas and heterocycles [1]. We recently dis-
covered that dinuclear complexes [CpꢁM(CO)2]2 (M =
Fe,Ru; Cpꢁ = C5H5,C5Me5) catalyze the allylic amina-
tion of olefins [2] and the indolization of alkynes [3] by
nitroarenes/CO) (Scheme 1). These novel transforma-
tions feature high regioselectivity with respect to the
hydrocarbon component with the ArN-unit being intro-
duced at the less substituted carbon of the substrate. A
photo-assisted, low pressure variant of the [Cp*Fe-
*
Corresponding author. Fax: +1 405 325 6111.
E-mail address: knicholas@ou.edu (K.M. Nicholas).
0022-328X/$ - see front matter ꢀ 2005 Elsevier B.V. All rights reserved.
doi:10.1016/j.jorganchem.2005.06.045

4728
J.C. Stephens et al. / Journal of Organometallic Chemistry 690 (2005) 4727–4733
R
ArHN
R
(1)
(2)
Ar NO
2
CO (10-50 atm)
( + CO )
2
[CpM(CO) ] (cat)
2 2
R
( M = Fe, Ru )
R
120-160 °C
N
H
Scheme 1.
intermediates and have provided evidence for the
involvement of mononuclear complex intermediate(s)
in which both the olefin and an organonitrogen species
are associated.
2. Results and discussion
The capability of producing [CpFe(CO)2L]+ com-
plexes by oxidation of [CpFe(CO)2]2 (1) in the presence
of appropriate ligands L [15] led us first to carry out the
reaction of dimer 1 with ferrocenium salts and nitroso-
benzene (CH2Cl2, r.t., 14–15 h, Scheme 2). Selective pre-
cipitation and trituration of the product mixture allowed
the isolation of two metal complexes and detection of a
third. A major product proved to be [CpFe(CO)3]BF4
based on its spectral data [16]. A dark brown second
compound isolated, 2, was devoid of metal carbonyls
judging from its IR spectrum, possessed one or more Ar-
To further probe the nature of the reactive complexes
involved in these reactions we are seeking to prepare and
establish the reactivity of CpM-complexes of organoni-
trogen species which could be prospective intermediates.
Since low valent metal complexes can serve as one-
electron reductants of nitroarenes (oxidizing the organo-
metallic) [11], we considered that cationic CpM-complexes
of organonitrogen species could be possible intermediates.
Accordingly, the complex [CpFe(CO)2(g1-(O)-Ph-
NO2)]PF6 was prepared and structurally characterized,
but found to be unreactive towards olefins [12].
Metal carbonyl-assisited deoxygenation of a nitroa-
rene would initially produce a nitrosoarene species.
Although metal complexes of C-nitroso compounds
are well known and exhibit a diversity of coordination
modes, their reactivity has not been significantly devel-
oped [13]. We thus sought to obtain corresponding
cyclopentadienylmetal nitrosoarene (ArNO) complexes
and to investigate their relevant reactivity vis a vis the
allylic amination reaction. We describe here the prepara-
tion and structural elucidation of the first structurally
characterized CpFe-complexes of nitrosoarenes [14]
and investigate the reactivity of one of these towards a
representative olefin and 1,3-diene, reactions which bear
on the possible role of such complexes in the Fp-cata-
lyzed allylic amination reactions.
1
NOx and Cp moieties based on its H NMR spectrum,
and appeared to be dinuclear based on its ESI-mass
spectrum. The detailed structure of 2 was revealed by
X-ray diffraction and found to be {[CpFe-l-(g2-(N,O)-
PhNO)]2-l-NHPh}BF4; the cationic portion of 2 is
shown in Fig. 1. The cationic unit has two CpFe moie-
ties bridged by two g2-N,O-bonded nitrosobenzene
units and one bridging phenyl amido unit. Formulation
of the –NHPh fragment is based in part on electron
counting considerations (18 electron count on each iron
without a M–M bond); it is also supported by IR and 1H
NMR absorptions assigned to the N–H unit and the
apparent H-bonding interaction to the BFÀ4 ions in the
crystal structure (see Supporting Information). The
bridging PhNO coordination mode in 2 has been ob-
served in some other dinuclear complexes [13]. Although
the two PhNO units are environmentally inequivalent
[Cp2Fe]BF4
[CpFe(CO)2]2
+
[CpFe(CO)3]BF4
+
PhNO
CH2Cl2
Ph
Ph
+
N
O
O
[CpFe(CO)2(PhNH2)]BF4
+
Fe
N
Fe
N
H
Ph
2
Scheme 2.

J.C. Stephens et al. / Journal of Organometallic Chemistry 690 (2005) 4727–4733
4729
AgPF
-
6
PF
6
+
CpFe(CO) I
PhNO
2
CH Cl
2
2
+
Fe
O
OC
N
CO
Ph
3
Scheme 3.
Fig. 1. X-ray ORTEP diagram for the cation of 2. Thermal ellipsoids
are shown at the 50% level.
because of their relationship with the bridging PhNH
unit (one syn, one anti), the N–O bond lengths are the
˚
same (1.318/1.319 0.002 A, partial listing in Fig. 1).
These distances are somewhat longer than those of free
˚
ArNO monomers (ca. 1.25 A) [13], suggesting a degree
of Fe-to-NO p* backbonding. The corresponding Fe–
N and Fe–O distances at the two iron atoms are also
very similar, showing that the PhNH unit is symmetri-
cally bridged between the two irons, the result of a 3-
center-4-electron interaction. A minor iron-containing
product detected in the ferrocenium-induced reaction
of Fp2 with PhNO was tentatively identified as [CpFe-
(CO)2(PhNH2)]BF4 based on a comparison of its spec-
tral characteristics with an authentic sample [17]
prepared from the reaction of [CpFe(CO)2(THF)]BF4
with aniline.
The transformations involved in the reaction of Eq.
(1) are clearly complex, especially the formation of iron
complexes of reduced organinitrogen species, i.e., 2 and
[CpFe(CO)2(PhNH2)]BF4, under oxidative conditions.
The apparent redox imbalance could be accounted for
by the formation of N-oxidized organics (e.g. NO,
ArNO2, etc.), but we have not identified the potentially
volatile organic products of the reaction. The source of
hydrogen to produce these complexes is similarly un-
known but could be derived from the solvent CH2Cl2
or adventitious moisture.
Seeking a monoiron-nitrosobenzene complex for reac-
tivity studies, we investigated Ag+-induced halide
abstraction from CpFe(CO)2I in the presence of poten-
tially ligating PhNO. Treatment of the iodide complex
with excess PhNO and one equivalent of AgSbF6
(CH2Cl2, r.t.) resulted in rapid disappearance of the iodo
complex as indicated by a series of color changes and IR
monitoring. Addition of ether afforded a maroon com-
pound 3 (83%), identified as [CpFe(CO)2(PhNO)]SbF6
by spectroscopic analysis and X-ray diffraction (Scheme
3). The molecular structure of 3, shown in Fig. 2, features
Fig. 2. X-ray ORTEP diagram for cation of 3. Thermal ellipsoids are
shown at the 50% level.
a typical [CpFe(CO)2L]+ piano-stool geometry with the
nitrosobenzene ligand coordinated in an g1-fashion
through N. This coordination mode is common to many
M–RNO complexes, including the only other structurally
characterized CpFe-derivative, CpFe(CO)(PPh3)(t-
BuNO) [14]. As with the latter, the nitroso ligand of 3
is nearly planar and approximately aligned with one of
the Fe–CO units (C2–Fe–N–O dihedral, 9ꢂ). This could
be the result of a stabilizing back-bonding interaction
from a filled iron d orbital to p* of the N–O unit. The
importance of such an interaction, however, is not appar-
ent from various probes of the Fe–N(O)Ar unit. The Fe–
N and N–O bond lengths are comparable in both com-
˚
˚
plexes (1.88 and 1.92 A; 1.23 and 1.22 A) and are typical
of Fe–N single and N–O double bonds, suggesting a weak
back-bonding interaction at most. A PM3 MO computa-
tional analysis [18] of 3 resulted in the energy-minimized
geometry shown in Fig. 3, similar to the experimental X-
ray structure with a slightly skewed ArNO plane relative
to Fe–CO (C2–Fe–N–O dihedral, 17ꢂ). The calculated
frontier bonding MOs of 3 (HOMO shown in Fig. 4(a))
are largely localized on the Cp–Fe fragment, giving little
evidence of an Fe-to-NO p* bonding interaction. The ori-
gin of the observed conformational preference for 3 in the
solid state structure thus remains uncertain and could

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J.C. Stephens et al. / Journal of Organometallic Chemistry 690 (2005) 4727–4733
1,3-butadiene as above, an efficient trapping agent for
PhNO via Diels-Alder reaction [20]. In this case the ad-
duct 5 was isolated as the major organic product,
strongly suggesting the intervention of free PhNO. Since
this result stands in contrast to the formation of allyl
amines from diene/alkene mixtures in the Fp2-catalyzed
reaction, complex 3 is excluded as an important interme-
diate in the catalytic allylic amination reactions.
3. Conclusions
Fig. 3. PM3-calculated structure of 3.
Two nitrosoarene complexes {[CpFe-l-(g2-(N,O)-Ph-
NO)]2-l-NHPh}BF4 (2) and [CpFe(CO)2(g1-PhNO)]Z
(3) have been prepared and structurally characterized.
Although MO calculations on 3 suggest potential elec-
trophilic reactivity of the coordinated nitrosoarene,
reactions of 3 with a-methyl styrene and dimethylbut-
adiene preclude the involvement of this compound as
an important intermediate in the allylic amination of
olefins by nitroarenes catalyzed by [CpFe(CO)2]2. Fur-
ther probes of the pathways of catalytic allylic amina-
tion and of the reactivity of coordinated C-nitroso
compounds are in progress.
result from crystal packing forces. The electronic charac-
ter of 3 is also of interest with respect to its reactivity,
especially towards nucleophilic agents such as olefins
(vide infra). The calculated LUMO (electron acceptor
orbital) of 3 is seen to be substantially localized at the
N(O)Ph unit (Fig. 4(b)) and the net positive charge is cal-
culated to be greatest at the coordinated nitrogen (+1.0).
Complex 3 could thus be anticipated to act as an N-cen-
tered electrophile [19].
To assess the viability of 3 as a possible intermediate
in allylic amination a sample of 3 was heated with excess
a-methyl styrene under typical catalytic conditions
(120 ꢂC, 41 atm. CO, Cl(CH2)2Cl). Only a trace of the
allyl amine 4 was detected (2%), along with [CpFe-
(CO)3]SbF6 and [CpFe(CO)2(PhNH2)]SbF6, which were
identified spectroscopically (Scheme 4). To determine if
the formation of the allyl amine was the result of PhNO
dissociation from 3 (and subsequent ene-reaction/reduc-
tion with AMS), 3 was also heated with 2,3-dimethyl-
4. Experimental
4.1. General
The following were prepared by literature methods:
(g5-C5H5)Fe(CO)2I [21], [(g5-C5H5)Fe(CO)2(PhNH2)]-
BF4[17].
Fig. 4. PM3-calculated HOMO (left) and LUMO (right) of complex 3.
Ph
(CO)
[CpFe(CO) ]PF
NHPh
3
6 +
Ph
(trace)
-
PF
6
+
Fe
O
OC
Ph
+
N
N
O
CO
Ph
[CpFe(CO) ]PF
3 6
(CO)
Scheme 4.

J.C. Stephens et al. / Journal of Organometallic Chemistry 690 (2005) 4727–4733
4731
4.2. Synthesis of {[CpFe-l-(g2-(N,O)-PhNO)]2-l-
NHPh}BF4 (2)
Table 1
˚
Selected bond lengths (A) and bond angles (ꢂ) for the cation of 2
Fe(1)–N(2)
Fe(1)–O(1)
Fe(1)–N(1)
Fe(2)–N(3)
Fe(2)–O(2)
Fe(2)–N(1)
N(2)–C(7)
N(3)–C(13)
O(1)–N(3)
O(2)–N(2)
1.8027(19)
[(g5-C5H5)Fe(CO)2]2 (4.8 g, 0.014 mol) and [(g5-
C5H5)2Fe]BF4 (7.5 g, 0.027 mol) were added to a
side-arm reaction flask and dissolved in 400 ml of dichlo-
romethane. Nitrosobenzene (4.4 g, 0.041 mol) was added
to the solution, whereupon its color changed from dark
blue to dark red-brown. The reaction mixture was stirred
for 14–15 h; then the volume was reduced by 80% at
reduced pressure. Addition of 150 ml of anhydrous ether
produced a dark red-brown precipitate. The precipitate
was collected and washed with 300 ml of anhydrous ether.
From the initial filtrate and ether washings dark brown
crystals of {[(g5-C5H5) Fe(PhNO)]2(l2-NHPh)}BF4 (2)
were isolated (1.2 g, 14%). IR (KBr, cmÀ1) 3259, 3102,
3063; 1H NMR (CD2Cl2, d) 7.8–7.2 (m, 10H), 7–6.6 (m,
5H), 5.4 (s, 5H), 5.3 (s, 5H); MS (ESI) 548 {[(g5-C5H5)-
Fe (PhNO)]2(l2-NHPh)}+, 441 {[(g5-C5H5)Fe]2(PhNO)-
(l2-NHPh)}+, and 349 {[(g5-C5H5)Fe]2(PhNO)}+.
Trituration of the aforementioned red-brown precipitate
with dichloromethane left insoluble [(g5-C5H5)Fe (CO)3]-
BF4, which was isolated by filtration (4.3 g, 55%); MS
(ESI) 204 [(g5C5H5)Fe(CO)3]+; IR (KBr, cmÀ1) 3126,
2125, 2067. The volume of the filtrate was reduced under
vacuum and addition of anhydrous ether produced a
red-brown precipitate (2.7 g) which was largely (>80%)
dinuclear 2 containing <20% of a second inseparable
compound, assigned to [CpFe(CO)2 (PhNH2)]BF4 based
on its IR and NMR spectra (see Tables 1 and 2).
1.9085(16)
1.986(2)
1.828(2)
1.9362(16)
1.9836(18)
1.446(3)
1.441(3)
1.319(2)
1.318(2)
N(2)–Fe(1)–O(1)
N(2)–Fe(1)–N(1)
O(1)–Fe(1)–N(1)
N(3)–Fe(2)–O(2)
N(3)–Fe(2)–N(1)
O(2)–Fe(2)–N(1)
Fe(2)–N(1)–Fe(1)
O(2)–N(2)–C(7)
O(2)–N(2)–Fe(1)
O(1)–N(3)–C(13)
O(1)–N(3)–Fe(2)
93.66(8)
87.05(8)
85.43(8)
93.09(8)
88.47(8)
83.93(7)
102.64(8)
109.53(17)
121.46(14)
107.87(19)
119.83(14)
Table 2
˚
Selected bond lengths (A) and bond angles (ꢂ) for cation of 3
Fe(1)–C(1)
Fe(1)–N(1)
N(1)–C(8)
O(2)–C(2)
Fe(1)–C(2)
O(3)–N(1)
O(1)–C(1)
O(2)–C(2)
1.808(3)
1.916(2)
1.450(3)
1.129(3)
1.810(3)
1.226(3)
1.133(3)
1.129(3)
C(1)–Fe(1)–C(2)
C(2)–Fe(1)–N(1)
O(3)–N(1)–C(8)
C(2)–Fe(1)–N(1)–O(3)
C(1)–Fe(1)–N(1)
O(3)–N(1)–Fe(1)
C(8)–N(1)–Fe(1)
91.02(13)
91.93(11)
114.4(2)
4.3. Synthesis of [(g5-C5H5)Fe(CO)2(g1-PhNO)]SbF6
(3)
À8.8(2)
96.03(10)
121.58(17)
123.66(17)
Solid AgSbF6 (2.5 g, 0.0073 mol) was added to a
solution
containing
(g5-C5H5)Fe(CO)2I
(2.2 g,
0.0072 mol) and PhNO (3.9 g, 0.036 mol) in 300 ml of
dichloromethane. Upon addition the reaction color in-
stantly changed from blue to orange and subsequently
to dark red-brown over the course of stirring for 4–
5 h. The mixture was filtered using a double-sided fritted
funnel and the volume reduced by 90%. The solution
was layered with 3 mL of anhydrous ether and placed
in a freezer at À10 ꢂC over night, affording dark maroon
crystals of 3 (3.1 g, 83%). IR (KBr, cmÀ1) 3124, 2086,
2044, 1131; 1H NMR (CD2Cl2, d) 7.99 (t, J = 8 Hz,
1H), 7.84 (d, J = 8 Hz, 2H) 7.70 (t, J = 8 Hz, 2H),
5.41 (s, 5H). MS (ESI) 162 [Fe(PhNO)]+, 228 [(g5-
C5H5)Fe(PhNO)]+, 284 [(g5-C5H5)Fe(CO)2(PhNO)]+.
approximately covered the full sphere of the reciprocal
space, were measured as a series of x oscillation frames
each 0.3ꢂ for 21 s/frame. The detector was operated in
512 · 512 mode and was positioned 6.12 cm from the
crystal. Coverage of unique data for 2 was 95.3% com-
plete to 56.6ꢂ (2h) and 99.3% complete to 55ꢂ (2h) for
3. Cell parameters for 2 were determined from a non-lin-
ear least squares fit of 8923 reflections in the range of
3.2ꢂ < h < 26.4ꢂ; a total of 27,306 reflections were mea-
sured. Cell parameters for 3 were determined from a
non-linear least squares fit of 8140 reflections in the
range of 2.3ꢂ < h < 28.3ꢂ; a total of 74,589 reflections
were measured. Crystal data and structure refinement
information for 2 and 3 are provided in Table 3.
5. X-ray structure determinations
Both structures were solved by the direct method using
the SHELXTL system [2], and refined by full-matrix least
squares on F2 using all reflections. All the non-hydrogen
atoms were refined anisotropically. All hydrogen atoms
The data for 2 were collected at 120(2) K and for 3 at
110(2) K on a Bruker Apex diffractometer [1] using Mo
˚
Ka (k = 0.71073 A) radiation. Intensity data, which

4732
J.C. Stephens et al. / Journal of Organometallic Chemistry 690 (2005) 4727–4733
Table 3
Crystal data and structure refinement for 2 and 3
Empirical formula
Formula weight
Temperature (K)
C92H98B3F12Fe6N9O8
2053.32
120(2)
C13H10F6FeNO3Sb
519.82
110(2)
˚
Wavelength (A)
0.71073
0.71073
Crystal system
Space group
Monoclinic
P2(1)/c
Monoclinic
C2/c
Unit cell dimensions
˚
a (A)
31.829(2)
16.2455(12)
19.0896(14)
7.8838(6)
˚
b (A)
˚
c (A)
43.150(3)
a (ꢂ)
b (ꢂ)
c (ꢂ)
90
90
103.6880(10)
90
8960.0(12)
92.6170(10)
90
6487.2(8)
3
˚
Volume (A )
Z
4
16
2.129
2.637
4000
0.18 · 0.14 · 0.08
2.14–27.50
Density (calculated) (Mg/m3)
1.522
1.033
4224
0.18 · 0.08 · 0.02
1.74–28.34
Absorption coefficient (mmÀ1
F(000)
Crystal size (mm3)
h Range for data collection (ꢂ)
Index ranges
Reflections collected
)
À42 6 h 6 42, À21 6 k 6 21, À23 6 l 6 22
À23 6 h 6 24, À10 6 k 6 10, À56 6 l 6 55
74,589
27,306
Independent reflections [R(int)]
Completeness to h = 26.50ꢂ
Absorption correction
Max. and min. transmission
Refinement method
Data/restraints/parameters
Goodness-of-fit on F2
Final R indices [I > 2r(I)]
R indices (all data)
21317 [0.0671]
99.5%
Semi-empirical from equivalents
0.9796 and 0.8359
Full-matrix least-squares on F2
21317/0/1175
7417 [0.0212]
99.3%
None
0.8167 and 0.6482
Full-matrix least-squares on F2
7417/0/451
1.008
1.122
R1 = 0.0482, wR2 = 0.0841
R1 = 0.0973, wR2 = 0.0967
0.849 and À0.852
R1 = 0.0265, wR2 = 0.0610
R1 = 0.0287, wR2 = 0.0619
1.023 and À0.770
À3
˚
Largest difference in peak and hole (e A
)
were included with idealized parameters. The asymmetric
unit of 2 contains three (C28H26N3O2Fe2) cations, three
BFÀ4 ions, and two (C4H10O) solvent molecules as shown
in Fig. S6. The F(9) and F(10) atoms are disordered as
evident from the large thermal parameters of these atoms.
The C28H26N3O2Fe2 cations form H-bonds with the F
atoms of BFÀ4 ions as listed in Table S6. The Final
R1 = 0.048 is based on 13,462 ‘‘observed reflections’’
[I > 2r(I)], and wR2 = 0.097 is based on all reflections
(21,317 unique reflections). The asymmetric unit of 3
2. Bruker (1997) SHELXTL: Version 6.12, Bruker AXS,
and Madison, Wisconsin.
Crystallographic data for the structural analyses of 2
and 3 have been deposited with the Cambridge Crystal-
lographic Data Centre and assigned numbers CCD
274509 (for 2) and 274510 (for 3).
5.1. Reaction of a-methyl styrene with
[(C5H5)Fe(CO)2(PhNO)]SbF6 (3)
contains two C13H10FeNO3 cations and two SbFÀ ions,
6
which pack along the crystallographic a-axis as shown
in the packing diagram (SI). The Final R1 = 0.027 is based
on 7001 ‘‘observed reflections’’ [I > 2r(I)], and wR2 =
0.062 is based on all reflections (7417 reflections).
The following X-ray data tables for 2 and 3 are pro-
vided in the Supporting Information:
Atomic coordinates and equivalent isotropic dis-
placement parameters; complete listing of bond lengths
and angles; anisotropic displacement parameters; hydro-
gen coordinates and isotropic displacement parameters;
torsion angles; hydrogen bonds.
a-Methyl styrene (0.50 ml, 3.9 mmol) was added to a
solution of [(g5-C5H5)Fe(CO)2-(PhNO)]SbF6 (0.41 g,
0.79 mmol) in 40 ml of 1,2-dichloroethane in the glass
liner of a stainless steel pressure vessel. The glass liner
was placed in a 125-ml stainless steel reactor (Parr) and
pressurized with CO (41 atm.). The reaction mixture
was stirred for 24 h at 110 ꢂC, cooled, and depressurized
(hood!). The volatiles were removed under vacuum, the
residue was triturated with Et2O, and the Et2O solution
was concentrated under vacuum. Preparative TLC of
the residue (3:2 dichloromethane/hexane) afforded a trace
of N-phenyl-2-phenyl-allylamine (0.004 g, 2%); 1H NMR
(CDCl3, d) 7.40 (d, J = 7 Hz, 2H) 7.33–7.086 (m, 5H),
6.68 (t, J = 7 Hz, 1H), 6.57 (d, J = 8 Hz, 2H), 5.41 (s,
1H), 5.27 (s, 1H), 4.10 (s, 2H), 3.87 (s, 1H); and several
1. Bruker (2002) SMART (version 5.625), GEMINI (version
1.0) and SAINT-plus (version 6.29), Bruker AXS Inc.,
Madison, Wisconsin.

J.C. Stephens et al. / Journal of Organometallic Chemistry 690 (2005) 4727–4733
4733
other unidentified minor organic products (GC–MS). The
References
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1
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Acknowledgements
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We thank the National Science Foundation for finan-
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Appendix A. Supplementary data
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Supplementary data associated with this article can be
found, in the online version, at doi:10.1016/j.jorganchem.
2005.06.045.