Synthesis and characterization of iron(II) complexes of 10- and 11-membered triphosphamacrocycles

Article abstract of DOI:10.1021/om060798g

The complex [(η⁵-Me₃SiC₅H ₄)Fe(10aneP₃-H₂H₃)]⁺, where Me₃SiC₅H₄ is trimethylsilylcyclopentadienyl and 10-aneP₃-H₂,C ₂H₃ is 1-vinyl-1,4,8-triphosphacyclodecane, has been prepared by the base-catalyzed template cyclization of 1,3-bis(phosphino)propane (1,3-bpp) and trivinylphosphine (tvp) at the metal center. A related radical-initiated iron-template reaction between 1,2-bis(phosphino)ethane (1,2-bpe) and triallylphosphine (tap) gave [(η⁵-C ₅Me₅)Fe(Me-10aneP₃-H₂,C ₃H₅)]⁺, where C₅Me₅ is 1,2,3,4,5-pentamethylcyclopentadienyl and Me-10aneP₃-H ₂.C₅H₅ is the unsymmetric 10-anePs derivative 1-allyl3-methyl-l,4,7-triphosphacyclodecane. This macrocycle is the result of two intramolecular hydrophosphination reactions, one that generates a five-membered (chelate) ring with an exo-methyl group and one a six-membered chelate. The [(η⁵-Cp^R)Fe]⁺ fragment also controls the cyclization of 1,2-bis(diallylphosphino)-ethane with phenylphosphine to give a ternary complex containing the symmetrical 11-membered macrocycle 1-phenyl-4,8-diallyl-l,4,8-triphosphacycloundecane, in addition to the unsymmetrical 10-aneP₃ derivative.

Full text of DOI:10.1021/om060798g

Organometallics 2007, 26, 377-386
377
Synthesis and Characterization of Iron(II) Complexes of 10- and
11-Membered Triphosphamacrocycles
Andrew R. Battle, Peter G. Edwards,* Robert Haigh, David E. Hibbs, Dongmei Li,
Sam M. Liddiard,† and Paul D. Newman
School of Chemistry, Cardiff UniVersity, Park Place, Cardiff, CF10 3AT, U.K.
ReceiVed September 1, 2006
The complex [(η5-Me3SiC5H4)Fe(10aneP3-H2,C2H3)]+, where Me3SiC5H4 is trimethylsilylcyclopenta-
dienyl and 10-aneP3-H2,C2H3 is 1-vinyl-1,4,8-triphosphacyclodecane, has been prepared by the base-
catalyzed template cyclization of 1,3-bis(phosphino)propane (1,3-bpp) and trivinylphosphine (tvp) at the
metal center. A related radical-initiated iron-template reaction between 1,2-bis(phosphino)ethane (1,2-
bpe) and triallylphosphine (tap) gave [(η5-C5Me5)Fe(Me-10aneP3-H2,C3H5)]+, where C5Me5 is 1,2,3,4,5-
pentamethylcyclopentadienyl and Me-10aneP3-H2,C3H5 is the unsymmetric 10-aneP3 derivative 1-allyl-
3-methyl-1,4,7-triphosphacyclodecane. This macrocycle is the result of two intramolecular hydrophosphination
reactions, one that generates a five-membered (chelate) ring with an exo-methyl group and one a six-
membered chelate. The [(η5-CpR)Fe]+ fragment also controls the cyclization of 1,2-bis(diallylphosphino)-
ethane with phenylphosphine to give a ternary complex containing the symmetrical 11-membered
macrocycle 1-phenyl-4,8-diallyl-1,4,8-triphosphacycloundecane, in addition to the unsymmetrical 10-
aneP3 derivative.
one major drawback; as the metal-macrocycle unit is very
robust, it is not easy to remove the product macrocycle from
its template.
Introduction
Unlike their nitrogen analogues, homoleptic macrocyclic
phosphines represent a rare class of ligand. Some of the apparent
lack of interest relates to the difficulty, perceived or otherwise,
of their preparation and, for most derivatives, their inherent
instability to air. Small-ring macrocyclic phosphines are likely
to be prized ligands, as it is anticipated that they will produce
highly robust metal complexes capable of outperforming similar
complexes of acyclic derivatives already employed so success-
fully in coordination chemistry and homogeneous catalysis. As
the majority of metal-promoted catalysis requires mutually cis
coordination sites in order to facilitate the desired transforma-
tions, triphosphamacrocycles are preferred to tetraphosphorus
species, as the latter, unless they are sufficiently flexible, tend
to coordinate in a square plane.
There are three main methods for the template synthesis of
triphosphamacrocycles, namely, the 1+1+1, 2+1, and 3+0
approaches. In the 1+1+1 closure, all three chelate rings of
the macrocycle are formed successively at the metal center from
three appropriately functionalized monodentate phosphines. The
2+1 approach requires the formation of only two chelate rings,
as one is already present in a prebound bidentate diphosphine,
while the 3+0 approach utilizes a coordinated terdentate P3
ligand and requires just one ring closure to give the macrocycle.
Surprisingly, although this latter approach would appear to be
the simplest, no literature examples exist for this kind of
chemistry. One restriction may be the lack of suitable linear
triphosphorus ligands as necessary precursors.
The first triphosphorus macrocycles were prepared by Kyba
using high-dilution techniques to give 12- to 14-membered
cyclo-P3 ligands as isomeric mixtures.1 Kyba noted that the
tertiary phosphines in his ligands inverted at high temperature,
enabling the preparation of a number of metal complexes with
facially capping 11-aneP3 ligands.1 Although this remains a
significant landmark in the development of homoleptic phos-
phorus macrocycle chemistry, template methods have largely
superseded the high-dilution techniques as the method of choice
for the preparation of P-containing macrocycles. Template
methods offer the advantage of controlling the stereochemistry
of the resultant ligand as the desired syn, syn all-cis form. This
is crucial in smaller and/or more rigid systems containing bulky
groups where the barrier to inversion at the phosphorus centers
may be prohibitively high. However, the template method has
The first example of the use of a template method for the
preparation of a P3 macrocycle was that of Norman and co-
workers.2 The synthesis of 12-aneP3H3 was achieved by the
radical-induced 1+1+1 coupling of three allylphosphine ligands
in cis-[Mo(CO)3(H2PC3H5)3].2 This elegant chemistry estab-
lished the template method for the preparation of triphosphorus
macrocycles. However, Norman was unable to exploit the ligand
system, as methods for the removal of the macrocycle from the
template eluded him. Our group was able to achieve the
liberation of tritertiary derivatives of the type 12-aneP3-R3,
enabling a study of the rich coordination chemistry of these
intriguing ligands.3 Aside from this incipient example, there are
only two further examples of the successful synthesis of P3
macrocycles by the 1+1+1 method: the first uses a modifica-
tion of the Norman procedure employing [(η5-C5H5)Fe]+ as the
template,4 while the second generates a unique 45-aneP3 ligand
* Author for correspondence. E-mail: Edwardspg@cardiff.ac.uk.
† Deceased
(1) (a) Kyba, E. P.; John, A. M.; Brown, S. B.; Hudson, C. W.; McPhaul,
M. J.; Harding, A.; Larsen, K.; Niedzwiecki, S.; Davis, R. E. J. Am. Chem.
Soc. 1980, 102, 139. (b) Kyba, E. P.; Davis, R. E.; Liu, S.-T.; Hassett, K.
A.; Brown, S. B. Inorg. Chem. 1985, 24, 4629. (c) Kyba, E. P.; Brown, S.
B. Inorg. Chem. 1980, 19, 2159.
(2) Diel, B. N.; Brandt, P. F.; Haltiwanger, R. C.; Norman, A. D. J. Am.
Chem. Soc. 1982, 104, 4700.
(3) (a) Edwards, P. G.; Fleming, J. S.; Liyanage, S. S. Inorg. Chem.
1996, 35, 4563. (b) Edwards, P. G.; Fleming, J. S.; Liyanage, S. S. J. Chem.
Soc., Dalton Trans. 1996, 1801.
10.1021/om060798g CCC: $37.00 © 2007 American Chemical Society
Publication on Web 12/10/2006

378 Organometallics, Vol. 26, No. 2, 2007
Scheme 1. Synthesis of Symmetrical 10-aneP3 Iron Macrocycle Complexesa
Battle et al.
a Reagents and conditions: (i) 1,3-diphosphinopropane, CH3CN/PhMe; (ii) trivinylphosphine, 1,2-dichlorobenzene/1,2-dichloroethane; (iii) NEt3,
1,2-dichlorobenzene/1,2-dichloroethane, 70 °C; (iv) H2, Pd/C (10%), EtOH; (v) KOBut, THF, -78 °C, EtBr.
via a Grubbs’ type methathesis coupling of the terminal
unsaturated groups at the ends of lengthy alkenyl substituents
on coordinated phosphines.5
lengths) to support the synthesis of 1,4,7-triphosphacyclononanes
by such methods.3b Structural studies indicate that the distance
between adjacent phosphorus atoms, measured by the non-
bonded P‚‚‚P distance, is typically around 3.4 Å for the Mo-
(CO)3 template and 3.3 Å for the Cr(CO)3 analogues. For a
nine-membered ring to form in the preparation of 1,4,7-
triphosphacyclononanes, modeling suggests that the nonbonded
P‚‚‚P distance in a tricarbonylchromium complex should be
around 3.0 Å. It is not clear what limit this template might have
in terms of macrocyclic ring size, although we have been unable
to prepare any macrocycle smaller than 12-membered with either
Mo(CO)3 or Cr(CO)3 as the supporting unit. The alternative
template, [(η5-RCp)Fe]+, where RCp is a variously substituted
cyclopentadienyl group, has features that facilitate the formation
of smaller macrocycles. The success of this template relates to
the shorter Fe-P bond lengths, the ability to vary the nature of
the substituents on the periphery of the Cp unit, and the facility
to incorporate a bidentate and monodentate phosphine sequen-
tially without compromising the facial geometry at the metal
center. Variation in substituents (R) of the RCp spectator ligand
introduces the opportunity to manipulate the steric influence of
the spectator ligand and hence the nonbonded distance between
precursor coordinated phosphines, a feature absent in the Cr/
Mo(CO)3 templates. This template methodology has already
provided an alternative synthesis of 12-aneP3-H3, and we have
presented some preliminary results of the preparation of
asymmetric 10-aneP3 and 9-aneP3 derivatives using such
methods.6 This has been extended to include symmetric 10-
aneP3 types and 11-aneP3 macrocycles, full details of which
are presented here.
The 2+1 approach has been used by us for the synthesis of
a number of triphosphamacrocycles including the elusive
9-aneP3-R3 ligand.6 These versatile 2+1 methods employ [(η5-
CpR)Fe]+ units as templates and are not restricted to hydro-
phosphination type rections but also include Michael-type
additions and SN2 substitutions at fluoroarylphosphines.6 This
paper establishes this type of approach as a versatile one through
the iron-based template synthesis of symmetric and asymmetric
10-aneP3 and symmetric 11-aneP3 derivatives, completing the
series from 9- to 12-membered triphosphamacrocycles available
using these techniques.
Results and Discussion
Molybdenum(0) and chromium(0) tricarbonyl fragments are
effective templates for intramolecular cyclophosphinations of
allylphosphine, allowing access to a number of 12-aneP3
macrocycles. However, they have not provided smaller ring
triphosphamacrocycles by related templated hydrophosphina-
tions of vinylphosphines. We have speculated that the distance
between the reactive centers of the phosphorus-containing
precursors in the M(CO)3 templates is too great (as a conse-
quence of the respective metal radii and the long M-P bond
(4) Price, A. J.; Edwards, P. G. J. Chem. Soc., Chem. Commun. 2000,
899.
(5) Bauer, E. B.; Ruwwe, J.; Martin-Alvarez, J. M.; Peters, T. B.; Bohling,
J. C.; Harnpel, F. A.; Szafert, S.; Lis, T.; Gladysz, J. A. J. Chem. Soc.
Chem. Commun. 2000, 2261.
(6) (a) Edwards, P. G.; Whatton, M. L. Dalton Trans. 2006, 442. (b)
Edwards, P. G.; Haigh, R.; Li, D.; Newman, P. D. J. Am. Chem. Soc. 2006,
128, 3818. (c) Edwards, P. G.; Newman, P. D.; Hibbs, D. E. Angew. Chem.,
Int. Ed. 2000, 39, 2722. (d) Edwards, P. G.; Newman, P. D.; Malik, K. M.
A. Angew. Chem., Int. Ed. 2000, 39, 2922.
Symmetric 10aneP3 Macrocycle Complexes. The synthesis
of the symmetric 1-vinyl-1,4,8-triphosphacyclodecane was
achieved by the reaction of 1,3-bis(phosphino)propane with
trivinylphosphine on the iron(II) template (Scheme 1). The

Iron(II) Complexes of Triphosphamacrocycles
Organometallics, Vol. 26, No. 2, 2007 379
chemistry is related to that used for the preparation of the
analogous 9-aneP3 derivative whereby two new chelate rings
are formed in a stepwise fashion by the Michael-type nucleo-
philic addition of a coordinated primary phosphide to a
neighboring vinylic carbon. In contrast to the analogous 1,2-
bis(phosphino)ethane (1,2-bpe) system, the 1,3-bis(phosphino)-
propane (1,3-bpp) precursor complex, [(η5-Me3SiC5H4)Fe(1,3-
bpp)(CH3CN)]+, 1 (Me3SiC5H4 is trimethylsilylcyclopentadienyl),
cannot be made by irradiating [{η5-Me3SiC5H4}Fe(CO)2(CH3-
CN)]+ in the presence of 1 molar equiv of phosphine, as this
leads to intractable product mixtures. Rather, the [{η5-(Me3Si)-
C5H4}Fe(CH3CN)3]+ complex must be generated before addition
of the phosphine; [(η5-Me3SiC5H4)Fe(1,3-bpp)(CH3CN)]+, 1,
is then obtained cleanly and in high yield after the addition of
1 molar equiv of 1,3-bpp. The remaining acetonitrile ligand in
1 is replaced by trivinylphosphine upon heating in hydrochlo-
rocarbons, and the subsequent base-catalyzed macrocyclization
chemistry proceeds as for the analogous 9-aneP3-vin complex.6b
Yields here are generally poorer than those for the synthesis of
the related [(η5-RCp)Fe(9-aneP3-H2,C2H3)]+ complexes, and
there is a strong preference for the mono- and bis(trimethylsilyl)-
cyclopentadienyl, η5-Me3SiC5H4 or η5-(Me3Si)2C5H3, units in
the template. Unsubstituted C5H5 and permethylated C5Me5 were
not suitable for the formation of 10-aneP3-H2,C2H3. In this case,
the lower yields compared to the related [(η5-RCp)Fe(9-aneP3-
H2,C2H3)]+ complexes are, in part, a consequence of the
increased formation of insoluble precipitates during the reaction.
The nature of these solids is undetermined, but they are
presumably the products of unwanted intermolecular coupling.
The macrocyclic product [{η5-Me3SiC5H4}Fe(10-aneP3-
H2,C2H3)]PF6, 4, is a yellow solid that may be crystallized from
ethanol. Crystals suitable for single-crystal X-ray analysis were
not obtained, as the complex tended to form clusters of very
fine, friable needles. The 31P{1H} NMR spectrum consists of a
low-field triplet at δ 126.9 ppm (2JP-P 33 Hz) and an upfield
doublet with the same coupling constant at δ 56.0 ppm. The
former is assigned to the unique tertiary phosphorus and the
latter to the two equivalent secondary phosphines; this was
confirmed on inspection of the proton-coupled 31P NMR
Figure 1. Two views of the crystal structure of the cation of 6,
[(η5-Me3SiC5H4)Fe(10-aneP3-Et3)]+: (a) approximately parallel to
the SiMe3Cp plane; (b) approximately perpendicular to the Cp plane
with the atom-labeling scheme. Ellipsoids are drawn at the 50%
probability level. Selected bond lengths (Å): Fe1-Cp(centroid) 1.730-
(6), Fe1-P2 2.1784(10). Fe1-P1 2.1788(10), Fe1-P3 2.1921(10),
P1-C16 1.826(4), P1-C15 1.827(4), P1-C9 1.847(4), P2-C18
1.822(4), P2-C10 1.833(4), P2-C11 1.840(4), P3-C20 1.836(4),
P3-C13 1.840(4), P3-C12 1.847(4), Si1-C6 1.857(5), Si1-C8
1.860(4), Si1-C7 1.865(4), Si1-C1 1.866(4), Selected bond angles
(deg): P1-Fe1-Cp(centroid) 129.0, P2-Fe1-Cp(centroid) 125.0, P3-
Fe1-Cp(centroid) 126.8, P2-Fe1-P1 86.50(4), P2-Fe1-P3 85.85-
(4), P1-Fe1-P3 90.12(4), C16-P1-C15 101.27(19), C16-P1-
C9 101.73(19), C15-P1-C9 102.9(2), C16-P1-Fe1 119.36(13),
C15-P1-Fe1 117.88(14), C9-P1-Fe1 111.35(13), C18-P2-C10
103.4(2), C18-P2-C11 103.9(2), C10-P2-C11 104.44(19),
C18-P2-Fe1 122.29(15), C10-P2-Fe1 111.21(14), C11-P2-
Fe1 110.00(15), C20-P3-C13 102.9(2), C20-P3-C12 103.40-
(19), C13-P3-C12 103.64(19), C20-P3-Fe1 116.55(13), C13-
P3-Fe1 118.82(13), C12-P3-Fe1 109.79(14). Torsion angle
(deg): C3-C2-C1-Si1 15.7.
1
spectrum, which showed a doublet with JP-H ) 364 Hz for
2
the secondary phosphines. The JP-P value is sensitive to the
ring size of the macrocycle, as will be discussed below.
The vinyl function in [{η5-Me3SiC5H4}Fe(10-aneP3-H2,C2H3)]+,
4, was reduced cleanly with 10% palladium on carbon in ethanol
to give [{η5-Me3SiC5H4}Fe(10-aneP3-H2,Et)]+, 5, in quantitative
yield. The 31P{1H} NMR spectrum of 5 is very similar to that
of the vinyl precursor 4, but the tertiary phosphine in 5 resonates
at δ 137.3 ppm, approximately 10 ppm downfield of the
precursor; this is typical for dialkylvinylphosphines compared
to analogous dialkylethylphosphines. The triethyl system [(η5-
Me3SiC5H4)Fe(10-aneP3-Et3)]+, 6, is obtained after the ethyla-
tion of the secondary phosphines in 5 with bromoethane in the
presence of 2 molar equiv of potassium tert-butoxide. As for
the synthesis of the related [(η5-RCp)Fe(9-aneP3-Et3)]+, where
R ) Me3SiC5H4 or (Me3Si)2C5H3, the trimethylsilyl groups are
lost if excess KOtBu is employed.
The [(η5-Me3SiC5H4)Fe(10-aneP3-Et3)]PF6, 6, thus obtained
can be crystallized from methanol on cooling. A single-crystal
X-ray structure of the complex is shown in Figure 1. The
structure shows the Me3SiC5H4 and 10-aneP3 ligands to be
facially capping the pseudo-octahedral metal center as expected.
The Fe-P bond lengths are 2.1788(10) and 2.1921(10) Å for
the two phosphorus donors incorporated in one six- and one
five-membered chelate {hereafter defined as P(6,5)}and 2.1784-
(10) Å for the unique phosphorus that is a component of two
five-membered chelates {defined as P(5,5) in subsequent
discussion}. These Fe-P bond lengths are comparable to those
observed in [(η5-Me3SiC5H4)Fe(9aneP3Et3)]+, where values of
2.153(4), 2.178(4), and 2.196(5) Å are observed.6b The P-Fe-P
angles are 90.12(4)° for the six-membered ring and 86.50(4)°
and 85.85(4)° for the two five-membered chelates. These values
are comparable to those observed in the related 9-aneP3-R3
complexes.6b,d The six-membered ring adopts the expected chair
conformation, while the two five-membered rings have an
envelope conformation. The SiMe3 moiety is positioned directly
over the six-membered ring, which presumably minimizes steric
interactions with the nearest hydrogen-hydrogen contacts at

380 Organometallics, Vol. 26, No. 2, 2007
Scheme 2. Synthesis of Unsymmetrical 10-aneP3 Iron Macrocycle Complexesa
Battle et al.
a a, R ) phenyl; b, R ) benzyl; c, R ) allyl; d, R ) 2-propyl. Reagents and conditions: (i) 1,2-diphosphinoethane, hν, CH3CN; (ii)
diallyl(phenyl)phosphine, 1,2-dichloroethane; (iii) AIBN, toluene; (iv) aq NaOH, CHCl3.
2.28 Å. This interaction causes the bond to the silicon atom to
be distorted 15.7° from the C5 plane of the cyclopentadienyl
ring. In the analogous 9-aneP3 complex, the distortion is slightly
greater at 16.3°.6b Of the five Fe-C bond lengths, that to the
carbon bearing the silyl group is the longest, at 2.153(3) Å (the
distance to the ring centroid is 1.730(6) Å).
membered macrocyclic complex 10a instead of the anticipated
species with a symmetric 11-membered ring. This is the result
of an internal hydrophosphination of one of the allylic functions
generating an exo-methyl group as opposed to inclusion of all
carbons in the macrocyclic ring.6d The cyclization does occur
on heating alone, but this is impractically slow, hence the
addition of AIBN as a radical initiator. The radical-promoted
cyclization occurs over a 12-24 h period at 80 °C and is
conveniently monitored by 31P{1H} NMR spectroscopy. After
heating 8a with AIBN for 1 h, aside from the resonances for
8a, three discreet doublets of doublets correlating to one
secondary, one tertiary, and one primary phosphine are observed
in the 31P{1H} NMR spectrum at δ 109 (28, 26 Hz), 75 (34, 28
Hz), and 22 (34, 26 Hz) ppm, respectively. The chemical shift
of the secondary phosphine is entirely consistent with its
incorporation in two five-membered chelate rings. Thus, some-
what surprisingly, it is the five-membered ring that is formed
first by an initial internal hydrophosphination of one of the allyl
functions (a 5-exo-trig ring closure) to give the intermediate
9a shown in Scheme 2. The subsequent formation of the six-
membered chelate (a 6-endo-trig ring closure) completes the
macrocycle. After 12-24 h at 80 °C, the only species detected
by 31P{1H} NMR spectroscopy is 10a.
The aforementioned chemistry is also appropriate for the bis-
(trimethylsilyl)cyclopentadienyliron(II) template, but as noted
previously with the 9-aneP3 derivatives, care has to be exercised
during the final ethylation, as the presence of excess base leads
to C-Si bond cleavage to give product mixtures that are not
easily separated. C5Me5 proved a less useful ligand for the
template chemistry to produce 10-aneP3-R3 derivatives, with
greatly reduced yields in macrocyclic products being obtained
when this derivative was employed. Likewise, the nonsubstituted
Cp templates did not give easily isolable materials when used
for the synthesis of the symmetric 10-aneP3 macrocycles.
Asymmetric 10-aneP3 Systems. The synthesis of the asym-
metric 10-aneP3 macrocyclic complexes with the preferred
1,2,3,4,5-pentamethylcyclopentadienyl template is summarized
in Scheme 2. The coordinated acetonitrile in [(η5-C5Me5)Fe(1,2-
dpe)(CH3CN)]+, 7, is readily substituted with either triallylphos-
phine or tertiary diallylphosphines upon heating in 1,2-
dichloroethane to give complexes of the type [(η5-C5Me5)Fe(1,2-
dpe)(PRR′2)]BF4, 8, as yellow or orange solids in quantitative
yield. The complexes are characterized by their 31P{1H} NMR
spectra, which consist of the expected A2X pattern at δ 41.2t
and 10.8d (8a), 45.4t and 12.0d (8b), 46.1t and 13.2d (8c), and
51.9t and 13.0d (8d). The doublets are due to the primary
phosphines, as confirmed from the proton-coupled 31P spectra,
which show a typically large 1JP-H coupling constant of around
350 Hz. Heating the ternary [(η5-C5Me5)Fe(1,2-dpe)(PRR’2)]-
BF4 complexes in toluene at 80 °C in the presence of AIBN
gave mixtures from which macrocyclic complexes of type 10
can be obtained as yellow, air- and moisture-stable solids in
variable yield. The radical-induced cyclization of [(η5-C5Me5)-
Fe(1,2-bpe){PPh(C3H5)2}]BF4 is known to produce the 10-
The cyclization chemistry using the 1,2,3,4,5-pentamethyl-
cyclopentadienyl template and 1,2-bpe extended to benzyldial-
lylphosphine (7b f 10b), triallylphosphine (7c f 10c), and
2-propyldiallylphosphine (7d f 10d), although yields were
appreciably lower with these tertiary phosphines. Indeed, the
presence of significant quantities of intractable byproducts
precluded isolation of 10c and 10d as pure compounds, and
they were characterized solely by 31P{1H} NMR spectroscopy
and mass spectrometry. Reasons for the relative failure of the
cyclization with diallyl(2-propyl)phosphine are unclear, while
the reactions with triallylphosphine were frustrated by unwanted
intermolecular coupling reactions. The reaction with tert-
butyldiallylphosphine failed to produce the desired [(η5-C5Me5)-

Iron(II) Complexes of Triphosphamacrocycles
Organometallics, Vol. 26, No. 2, 2007 381
Fe(1,2-dpe){P(t-C4H9)(C3H5)2}]BF4 precursor, and hence no
macrocyclic product could be obtained.
Altering the nature of the Cp fragment had a deleterious effect
on the yields of the asymmetric 10-aneP3 derivatives. Substitut-
ing C5Me5 for the mono- or bis-1,3-(trimethylsilyl)cyclopenta-
dienyl group led to the production of complex mixtures from
which we have been unable to isolate pure compounds. Some
of the unwanted byproducts were identified by mass spectrom-
etry as dimeric species resulting from intermolecular hydro-
phosphination. When unsubstituted C5H5 was employed with
PPh(C3H5)2, two major sets of resonances were observed in the
31P{1H} NMR spectrum of the reaction mixtures on completion
of the cyclization. The first set at δ 126.3t (36 Hz), 80.8dd (61,
36 Hz), and 74.7t (61, 36 Hz) ppm may be assigned to the
unsymmetrical [(η5-C5H5)Fe(Me-10-aneP3-H2,Ph)]+ complex,
and the second set, which appear in an approximately 1:2
intensity ratio at δ 77.7d (62 Hz) and 34.1t (62 Hz), are assigned
to the symmetrical [(η5-C5H5)Fe(11-aneP3-H2,Ph)]+ complex.
This was the only case where the 11-membered macrocycle
could be detected in solution by 31P NMR spectroscopy.
Unfortunately, it was not possible to separate these two isomers
by crystallization and/or chromatography, and other character-
ization data for the complexes are lacking. These observations
do, however, suggest that the peripheral bulk on the cyclopen-
tadienyl fragment has an influence on the outcome of the
reaction and the ring size of the resultant macrocycle. When
bulky, substituted Cp ligands are used, asymmetric 10-aneP3
macrocycles predominate, but formation of the symmetric 11-
aneP3 competes favorably when unmodified C5H5 is employed.
The 31P{1H} NMR spectra of the complexes 10a-d are
typically of an ABX type with a low-field triplet at δ 110-115
ppm assignable to the secondary phosphine that is a component
of two five-membered chelates and two doublets of doublets in
the δ 60-70 ppm range for the remaining phosphorus donors.
In the case of 10c, only a single doublet was observed to higher
field (δ 65.5) as a consequence of accidental equivalence of
the two respective phosphorus nuclei at the operating frequency
of the spectrometer (36.23 MHz). Further confirmation of the
structural assignments comes from the 13C{1H} DEPT NMR
spectra, where one methine carbon resonance is observed as a
doublet of doublets in addition to a doublet of doublets for the
unique methyl carbon (see Experimental Section). The 1H NMR
spectra of the complexes consist of overlapping, heavily coupled
multiplets in the aliphatic region; this is not surprising, as every
hydrogen in the macrocycle is unique. The CH3 group exo to
the ring is the exception, being observed as a doublet of doublets
Figure 2. Two views of the crystal structure of the cation of 10a,
1S,3R,4R,8R,Fe-[(η5-C5Me5)Fe(Me-10-aneP3-H2,Ph)]+: (a) ap-
proximately parallel to the Cp* plane; (b) approximately perpen-
dicular to the Cp plane with the atom labeling scheme. Ellipsoids
are drawn at the 50% probability level. Selected bond lengths (Å):
Fe1-Cp(centroid) 1.728(6), Fe1-P2 2.150(2), Fe1-P3 2.169(2), Fe1-
P1 2.195(2), P1-C11 1.833(6), P1-C22 1.841(6), P1-C17 1.853-
(6), P2-C19 1.821(7), P2-C20 1.853(8), P3-C21 1.812(8), P3-
C23 1.864(7), C22-C23 1.505(10), C23-C24 1.514(10). Selected
bond angles (deg): P1-Fe1-Cp(centroid) 131.2, P2-Fe1-Cp(centroid)
122.9, P3-Fe1-Cp(centroid) 127.0, P2-Fe1-P3 85.94(8), P2-Fe1-
P1 90.06(7), P3-Fe1-P1 85.97(7), C11-P1-C22 101.8(3), C11-
P1-C17 102.2(3), C22-P1-C17 102.1(3), C11-P1-Fe1 121.4(2),
C22-P1-Fe1 110.6(2), C17-P1-Fe1 116.2(2), C19-P2-C20
104.8(4), C19-P2-Fe1 122.0(3), C20-P2-Fe1 111.6(2), C21-
P3-C23 107.9(4), C21 P3 Fe1 110.1(3), C23-P3 Fe1-112.0(2),
C22-C23-P3 108.5(5), C24-C23-P3 114.2(6).
1
in the H spectrum at around δ 1.5 ppm (J ) 12 and 7 Hz).
The presence of three multiplets for the alkenic protons of the
allyl group at δH 5.64, 5.44, and 5.29 ppm in 10c and a
diastereomeric ABX pattern for the benzyl CH2 groups R to
phosphorus at δP 3.16 (dd, J ) 14, 5 Hz) and 2.87 (dd, J ) 14
and 5 Hz) ppm for 10b are other distinguishing features in the
1H NMR spectra of these complexes.
tion state from which it would arise. The structure of the 1S,
3R, 4R, 8R, Fe(R)-[(η5-C5Me5)Fe(Me-10-aneP3-H2,Ph)]+ enan-
tiomer (S,R,R,R,R-10a) is shown in Figure 2. The gross structure
resembles closely that of our previously reported P,P-dichloro
derivative, [(η5-C5Me5)Fe(Me-10aneP3-Cl2,Ph)]+, 11a,6c al-
though the Fe-P bond to the tertiary phosphine is a little longer
(2.195(2) Å) than the other two (2.150(2), 2.169(2) Å). The
P1-Fe-P3 and P2-Fe-P3 angles of the two different five-
membered chelate rings are almost identical, at 86.00(7)° and
85.97(8)°, respectively, and are both significantly smaller than
that of the six-membered chelate (P1-Fe-P2, 90.07°). These
values compare to bond lengths of 2.210(2) (Fe-PPh), 2.147-
(2) (Fe-PCl), and 2.153(2) Å (Fe-PCl) and angles of 84.51-
(8)°, 86.77(7)°, and 89.00(6)° for the two five-membered and
one six-membered chelate in 11a.6c Steric strain is less in
S,R,R,R,R-10a compared to the dichlorinated analogue, as
indicated by a reduced Fe-P-Cipso bond angle of 121.7(2)°
Hydrophosphination at the internal carbon of one of the allyl
groups in the synthesis of the [(η5-RCp)Fe(Me-10-aneP3-
H2,R′)]+ complexes creates five chiral centers, namely, the
methyl-bearing ring carbon, the three phosphorus donors, and
the iron center itself. There is no enantiocontrol during the
reaction and the complexes are isolated as racemic mixtures,
although the reaction is highly stereospecific in the formation
of the exo-methyl derivative. There is no evidence of the epimer
in the 1H NMR spectrum; this selectivity may be due to
unfavorable steric interactions with the cyclopentadienyl group
that destabilize the alternative endo-conformation or the transi-

382 Organometallics, Vol. 26, No. 2, 2007
Scheme 3. Synthesis of 11-aneP3 Iron Macrocycle Complexesa
Battle et al.
a Reagents and conditions: (i) 1,2-bis(diallylphosphino)ethane, CH3CN; (ii) PhPH2, CH2Cl2; (iii) RT, 14 days.
[cf. 122.4(7)° in 11a] and smaller deviations from coplanarity
for the methyl substituents and the ring carbons of the C5Me5
unit; the methyls are bent away from the metal by an average
of 7.1° compared to 10.8° in [(η5-C5Me5)Fe(Me-10-aneP3-Cl2,-
Ph)]+, 11a.6c
[(η5-C5H5)Fe]+ by visible light photolyses of a solution of [(η5-
C5H5)Fe(η6-C6H6)]+ containing 1 molar equiv of 1,2-tape. The
iron(II) precursors highlighted in Schemes 1 and 2 were not
appropriate for this synthesis, as the UV conditions needed for
labilization of the metal-carbonyls could compromise the P-allyl
functions. The complex [(η5-C5H5)Fe(1,2-tape)(MeCN)]+, 12,
was formed in good yield, and the final MeCN ligand was
replaced by phenylphosphine on stirring a solution of 12 and
PhPH2 at room temperature for several days to give 13. This
latter complex was not isolated because all attempts to purify
the compound were frustrated by its ready tendency to undergo
ring-closure reactions resulting in contamination by macrocyclic
products and their acyclic intermediates (which are readily
identified by their 31P NMR spectra). Solutions of 13 were thus
left for 14 days at room temperature to allow complete
cyclization to give a mixture of the desired 11-membered
triphosphamacrocycle complex [(η5-C5H5)Fe{11-aneP3-Ph,-
(C3H5)2}]+, 14, and the asymmetric 10-aneP3 derivative, [(η5-
C5H5)Fe{Me-10-aneP3-Ph,(C3H5)2}]+, 15. Efforts to acquire the
desired complex by UV-initiated coupling were unsuccessful,
with complex reaction mixtures resulting even after short-term
exposure to UV light. However, the reaction mixtures typically
consisted of 1:1 mixtures of the two isomers (14, 15) at all stages
of the cyclization, as determined by 31P{1H} NMR spectroscopy
(i.e., their rates of formation are similar). Although the 11-aneP3
complex could be isolated from this reaction, because of the
competitive formation of the unsymmetric [(η5-C5H5)Fe{Me-
10-aneP3-Ph,(C3H5)2}]+ complex, 15, the isolated yield was very
poor (5%). Unlike the 11-membered derivative, the 10-
membered complex could not be isolated in a pure state.
The chiral cyclopentadienyl derivative, neomenthylcyclopen-
tadienyliron(II), [(η5-neomenthCp)Fe(II)], was employed in an
effort to invoke some diastereoselectivity in the synthesis of
the unsymmetrical 10-aneP3 complexes. However, the yields
of macrocycle were poor with this template, and there was no
detectable diastereoselectivity by 31P and 1H NMR spectroscopic
analysis of the isolated products. The 31P{1H} NMR spectrum
of [(η5-neomenthCp)Fe(Me-10-aneP3-H2,Ph)]+, 10e, consisted
of two sets of AMX doublets of doublets, one for each
diastereoisomer. The intensities of all the peaks were equivalent,
suggesting no diastereoselectivity during the synthesis. This was
confirmed on inspection of the 1H NMR spectrum, which
revealed eight separate peaks of equal intensity for the four
unique cyclopentadienyl protons of each diastereomer.
As noted previously, if solutions of the disecondary macro-
cyclic complexes in chlorinated solvents are exposed to the
atmosphere, the secondary phosphines are chlorinated to give
complexes of the type [(η5-RCp)Fe(Me-10-aneP3-Cl2,R′)]+. This
is relatively slow in the absence of base, but is rapid when the
solutions are left in contact with aqueous sodium hydroxide.
The coordinated chlorinated phosphines resonate at δP > 200
ppm in the 31P{1H} NMR spectra (see Experimental Section).
We have previously commented on similar chlorinations
achieved with molybdenum(0) complexes of triphosphacy-
clododecanes.7
11-aneP3 Derivatives. The failure to isolate symmetric 11-
membered triphosphamacrocycle complexes from the reaction
of 1,2-dpe with triallyphosphine or tertiary diallylphosphines
was surprising, and different procedures for their synthesis were
required. The next obvious approach was to place the allylic
functions on the bidentate phosphine and to use a primary
monodentate phosphine as highlighted in Scheme 3. 1,2-Bis-
(diallylphosphino)ethane, 1,2-tape, was acquired from 1,2-bis-
(dichlorophosphino)ethane by reaction with 4 molar equiv of
allylmagnesium bromide. The diphosphine was coordinated to
The complex [(η5-C5H5)Fe{11-aneP3-Ph,(C3H5)2}]+, 14, was
crystallized from tetrahydrofuran as its hexafluorophosphate salt
and its structure determined by single-crystal X-ray analysis
(Figure 3). The average Fe-P bond lengths (2.197 Å) are greater
in this complex than in the crystallographically characterized
9-aneP3 and 10-aneP3 complexes, and more significantly, the
P-Fe-P bond angles for the two six-membered chelate rings
are expanded to 95.0° (average) compared to 90° for the
symmetric and unsymmetric 10-aneP3 complexes. This may
simply be a consequence of the larger ring size; however, this
is not the case for the 12-aneP3 complex [(η5-C5Me5)Fe(12-
aneP3-Et3)]+, where the average P‚‚‚P distance is 3.137(4) Å
(7) Jones, D. J.; Edwards, P. G.; Tooze, R. P.; Albers, T. J. Chem. Soc.,
Dalton Trans. 1999, 1945.

Iron(II) Complexes of Triphosphamacrocycles
Organometallics, Vol. 26, No. 2, 2007 383
for the asymmetric 10-aneP3 and 12-aneP3 complexes and (Me3-
Si)C5H4 for the symmetric 10-aneP3 complex. Observations from
the formation of the asymmetric 10-aneP3 and the 9-aneP3
macrocycles show that the nature of the Cp group has a direct
influence on the kinetics and efficiency of macrocycle formation,
with greater peripheral bulk generating higher yields of products
in shorter times. We have recently shown that increasing the
steric bulk of the Cp spectator ligand has a significant influence
on compressing P-Fe-P angles in related triphosphine and 12-
aneP3-R3 complexes with a consequent decrease in P‚‚‚P
distances.8 Although the electronic differences between the
dissimilar Cp donors may play a part, it is steric influences that
appear to control the cyclizations. Thus, the Cp ligands are not
simply spectator ligands in these systems but have a direct
influence on the cyclization and the nature of the resultant
products. This is presumably due to the bulkier (Me3Si)C5H4,
(Me3Si)2C5H3, and C5Me5 donors forcing the reactive centers
(phosphide lone pair and/or radical and alkenyl carbon) closer
together, enhancing the rate of macrocyclization. This steric
effect is observed in the crystal structures of the various
complexes by the Fe-P-Cexo angles, where Cexo is the R-carbon
of the nonring substituent(s) at P (ethyl, phenyl, allyl). The
values for these angles range from >125° in [(η5-C5Me5)Fe-
(9-aneP3-Et3)]+ 6d to an average of 122.1° in [(η5-Me3SiC5H4)-
Fe(9-aneP3-Et3)]+ 6b and are 122.9°, 122.5°, and 121.4° for the
unique Fe-P-Cexo angles in [{η5-(Me3Si)2C5H3}Fe(9-aneP3-
H2,C2H3)]+,6b [(η5-C5Me5)Fe(Me-10aneP3-Cl2,Ph)]+,6c and [(η5-
C5Me5)Fe(Me-10aneP3-H2,Et)]+, respectively, and average 119.4°
in [(η5-Me3SiC5H4)Fe(10-aneP3-Et3)]+. These values are all
appreciably greater than the Fe-P-Cexo angles in the [(η5-
C5H5)Fe{11-aneP3-Ph,(C3H5)2}]+, 14, complex, where values
of 115.7°, 115.29°, and 119.23° are observed. The comparable
angles in the [(η5-C5Me5)Fe(12-aneP3-Et3)]+ complex are only
slightly larger at 117.2° (average).8 Although this data must be
treated with caution because of the differences within the
complexes (notably differences in the number of five- and six-
membered chelates for each macrocycle), the observation of
increased cyclization rates and improved yields coupled with
the structural features do support the notion that the nature of
the Cp ligand does influence the cyclization, and, in this case,
they are not strictly simple spectator ligands.
Figure 3. Two views of the crystal structure of the cation of 14,
[(η5-C5H5)Fe{11-aneP3-Ph,(C3H5)2}]+: (a) approximately parallel
to the Cp plane; (b) approximately perpendicular to the Cp plane
with the atom-labeling scheme. Ellipsoids are drawn at the 50%
probability level. Selected bond lengths (Å): Fe1-C5 2.092(3),
Fe1-C3 2.094(4), Fe1-C4 2.100(3), Fe1-C1 2.109(3), Fe1-C2
2.110(3), Fe1-Cp(centroid) 1.722(4), Fe1-P1 2.1943(9), Fe1-P3
2.1954(10), Fe1-P2 2.2026(9), P1-C13 1.835(4), P1-C14 1.849-
(3), P1-C6 1.857(4), P2-C8 1.834(3), P2-C9 1.844(3), P2-C20
1.844(4), P3-C11 1.833(4), P3-C10 1.840(3), P3-C23 1.848(3),
C20-C21 1.498(5), C21-C22 1.309(5), C23-C24 1.499(5), C24-
C25 1.309(5). Selected bond angles (deg): P1-Fe1-Cp(centroid)
121.8, P2-Fe1-Cp(centroid) 126.8, P3-Fe1-Cp(centroid) 123.1, P1-
Fe1-P3 93.98(4), P1-Fe1-P2 95.93(4), P3-Fe1-P2 85.68(3),
C13-P1-Fe1 114.31(12), C14-P1-Fe1 115.71(11), C6-P1-Fe1
121.25(13), C8-P2-Fe1 119.15(12), C9-P2-Fe1 109.28(12),
C20-P2-Fe1 119.44(12), C11-P3-Fe1 118.79(12), C10-P3-
Fe1 111.50(12), C23-P3-Fe1 115.69(12), C13-P1-C14 101.59-
(17), C13-P1-C6 102.63(19), C14-P1-C6 98.38(16) C8-P2-
C9 102.10(16), C8-P2-C20 102.93(17), C9-P2-C20 101.25(16),
C11-P3-C10 104.01(17), C11-P3-C23 102.46(17), C10-P3-
C23 102.50(16), C22-C21-C20 125.0(4), C25-C24-C23 124.2-
(4).
The 31P NMR spectrum of 14 consists of a doublet at δ 81.0
ppm (2JP-P, 63 Hz) assigned to the allyl-bearing tertiary
phosphines and a triplet at δ 37.9 ppm (2JP-P, 63 Hz) for the
unique tertiary phenylphosphine of the macrocycle. These shifts
are determined by the nature of the phosphorus donors and tend
toward lower fields when the phosphorus is part of one or more
five-membered chelate rings.9 Trends within the 31P NMR
spectra can be identified that are characteristic of a given ring
size. The chemical shift of a given P donor becomes increasingly
positive along the series 12-aneP3 < 11-aneP3 < 10-aneP3 <
9-aneP3, consistent with the change from three six-membered
chelates through mixed six- and five-membered chelates to three
five-membered chelate rings.9 In addition, it appears that the
and the P-Fe-P angles average 90°.8 This distortion may also
be described by the nonbonded P‚‚‚P distances; in 14, those
between the phosphorus atom of the six-membered chelates are
substantially larger (3.266 and 3.210 Å) than the corresponding
distances in 6 (3.094 Å) and 10a (3.073 Å). In all cases, the
P‚‚‚P distances between the phosphorus atoms in the five-
membered chelates are similar (2.976, 2.985 Å in 6; 2.944, 2.975
Å in 10a; and 2.911 Å in 14). A distinction between all these
complexes is in the nature of the Cp unit, being unsubstituted
in the case of the current 11-aneP3 (14) as opposed to C5Me5
2
value of JP-P is also influenced by the ring size, being 63 Hz
for the symmetric [(η5-C5H5)Fe{11-aneP3-Ph,(C3H5)2}]+, 33 Hz
for [(η5-Me3SiC5H4)Fe(10-aneP3-H2,C2H3)]+, and 21 Hz for
[(η5-Me3SiC5H4)Fe(9-aneP3-H2,C2H3)]+ (the value for the 9-aneP3
derivatives is sensitive to the nature of the Cp group, but there
is little difference between unsubstituted Cp and the silylated
derivatives, and the trend is a genuine one).6b This again relates
to the individual chelate ring size or, more specifically, the
(8) Edwards, P. G.; Malik, K. M. A.; Ooi, L.-L.; Price, A. J. J. Chem.
Soc., Dalton Trans. 2006, 433.
(9) Pregosin, P. S.; Kunz, R. W. 31P and 13C NMR of Transition Metal
Complexes; Springer-Verlag: Berlin, 1979.

384 Organometallics, Vol. 26, No. 2, 2007
Battle et al.
2
1,3-bis(phosphino)propane in toluene (2.7 mL, 2.3 mmol) added
thereto. After stirring overnight, the solvent was removed in vacuo
and the orange residue washed with diethyl ether and recrystallized
from acetonitrile. Yield: 0.92 g (82%). 31P{1H} NMR {145.8 MHz,
(CD3)2CO, 20 °C }: δ -30.4 (s) ppm. 1H NMR {400 MHz, (CD3)2-
CO, 20 °C}: δ 5.06 (d br, 1JH,P ) 330 Hz, 4H, PH2), 4.83 (br, 2H,
Cp-H), 4.29 (br, 2H, Cp-H), 2.43 (s, 3H, CH3CN), 1.12 (t br, 4H,
CH2PH2), 0.32 (s, 9H, SiCH3) ppm. 13C{1H) NMR (100 MHz,
CDCl3, 20 °C): δ 134.9 (s, C), 92.6 (s, C), 81.7 (s, C), 75.5 (s, C),
22.9 (s, CH3) 13.9 (t, JC,P ) 18.5 Hz, CH2), 4.5 (d, JC,P ) 31.5
Hz, CH2), 0.03 (s, CH3) ppm. The compound failed to give
acceptable mass spectroscopic and analytical data and was used in
subsequent reactions as isolated.
(η5-Trimethylsilylcyclopentadienyl)(1-vinyl-1,4,8-triphosphacy-
clodecane)iron(II) Hexafluorophosphate, 4. A solution of 1 (1.0
g, 2.05 mmol) in a 1:1 mixture of chlorobenzene and 1,2-
dichloroethane (100 mL) was added to 2.3 mL (1 molar equiv) of
a 10% w/v solution of trivinylphosphine in toluene followed by
triethylamine (2 mL). The solution was heated to 70 °C and held
at this temperature for 48 h. The yellow solution was filtered, the
solvent removed in vacuo, and the residue extracted with ethanol
(2 × 50 mL). Removal of the ethanol gave the desired compound
as a bright yellow solid. Yield: 550 mg (51%). 31P{1H} NMR
{36.23 MHz, (CD3)2CO, 20 °C}: δ 126.9 (t, 2JP,P ) 33 Hz), 56.0
relevant P-Fe-P bond angle, with the largest values of JP-P
being associated with the larger intermetal bond angles and vice
versa. These observations are in accord with those for related
noncyclic species.
Liberation Studies. To date, none of the tertiary or secondary
triphosphine macrocycles have been successfully liberated from
the metal and the d6 octahedral Fe(II) template appears
kinetically remarkably inert and resistant to disruption by
conventional agents such as CN-. The nine-membered triph-
osphacyclononane has been liberated as its trioxide by exhaus-
tive oxidation,6b but the ligands described here remain unknown
in the free uncoordinated state. The iron center does undergo
reversible one-electron oxidation in most cases, although
attempts to scavenge the iron from the oxidized Fe(III)
complexes with various agents (CN-, EDTA, OH-) have not
been successful. These studies continue.
2
1
Conclusions
The cationic cyclopentadienyliron(II) template is very ver-
satile and allows incorporation of a range of different bidentate
and monodentate phosphines that are suitable precursors for
triphosphine macrocycle syntheses by intramolecular hydro-
phosphinations. The ability to selectively introduce di-primary
phosphines with a mono-tertiary phosphine, or alternatively a
di-tertiary phosphine with a mono-primary phosphine, allows
the formation of triphosphine macrocycles that bear either
secondary or tertiary phosphines and the subsequent opportunity
to functionalize these donors with a range of substituents. This
template also allows the manipulation of the steric bulk of the
spectator cyclopentadienyl group (and consequential influences)
by variation of its substituents. Increasing steric bulk has a
significant influence upon both the rates of ring closure reactions
and yields of products. In circumstances where the ring closure
reaction has a choice of P-C bonds it may form (e.g., in the
intramolecular hydrophosphination of P-allyl substituents),
increasing the steric bulk of the Cp ligand increases the
selectivity for the formation of the smaller ring alternative. In
the cyclopentadienyliron template system, control of both of
these variables (choice of precursor phosphines, choice of Cp
derivatives) is facile and appropriate combinations lead to a wide
range of triphosphine macrocycles from 9- to 12-membered
rings and with a range of secondary and tertiary alkyl or aryl
phosphine donors.
2
1
(d, JP,P ) 33 Hz) ppm. H NMR {400 MHz, (CD3)2CO, 20 °C}:
3
3
δ 6.81 (m, 1H, CH:CH2), 6.15 (dd, JH,P ) 34.7 Hz, JH,H ) 12.7
3
3
Hz, 1H, CH:CH2), 5.98 (t, JH,P, JH,H ) 18.5 Hz, 1H, CH:CH2),
5.98 (d br, 364 Hz, 2H, PH), 4.76 (br, 2H, Cp-H), 4.61 (br, 2H,
Cp-H), 2.6-2.4 (m, 8H, CH2), 2.2-2.0 (m, 4H, CH2), 1.48 (t, 2H,
CH2), 0.11 (s, 9H, SiCH3) ppm. 13C{1H) NMR {100 MHz, (CD3)2-
CO, 20 °C}: δ 135.8 (d, 1JC,P ) 36.0 Hz, CH:CH2), 127.9 (s, CH:
2
2
CH2), 97.6 (d, JC,P ) 5.0 Hz, CH), 86.8 (d, JC,P ) 5.0 Hz, CH),
82.5 (s, CH), 31.2 (d, 1JC,P ) 27.7 Hz, CH2), 21.0 (t, 1,2JC,P ) 15.0
Hz, CH2), 19.4 (m, CH2), 16.8 (s, CH2), 0.05 (s, CH3Si) ppm. MS
(APCI), m/z: 413 (100) [{η5-(Me3Si)Cp}FeL]+. Anal. Calcd for
C17H32P4F6SiFe (%): C, 36.57; H, 5.79. Found: C, 36.6; H, 5.8.
IR (KBr): 2325 m (νPH).
(η5-Trimethylsilylcyclopentadienyl)(1-ethyl-1,4,8-triphosphacy-
clodecane)iron(II) Hexafluorophosphate, 5. To a solution of 4
(0.556 g, 1.0 mmol) in ethanol (150 mL) was added 50 mg of
palladium on carbon (10%) catalyst, and the mixture was stirred
vigorously at room temperature. A stream of hydrogen gas was
bubbled at a low rate through the solution. The progress of the
reaction was monitored using 31P{1H} NMR spectroscopy. After
completion of the reaction (determined by complete loss of the 31
P
resonance at δP 126.9 ppm and concomitant appearance of a peak
at δP 137.1 ppm), the solution was filtered to remove the catalyst,
and the solvent was removed under reduced pressure. Yield of 3:
0.55 g, 1.0 mmol. 31P{1H} NMR {36.23 MHz, (CD3)2CO, 20 °C}:
δ 137.3 (t, 2JP,P ) 32 Hz), 56.4, (d, 2JP,P ) 32 Hz), 1H NMR {400
MHz, (CD3)2CO, 20 °C}: δ 5.94 (d, br, 1JH,P ) 352 Hz), 4.82 (d,
3JH,P ) 1.9 Hz, 2H, CpH), 4.65 (d, 3JH,P ) 1.9 Hz, 2H, CpH), 2.49-
2.23 (m, CH2, 8H), 1.91, (m, CH2CH3), 1.76-1.63 (m, CH2, 4H),
1.33 (m, CH3), 0.30 (s, CH3, 9H). 13C{1H) NMR {100 MHz, (CD3)2-
Experimental Section
The syntheses of the complexes were performed under nitrogen
using standard Schlenk line techniques. All solvents were freshly
distilled from sodium (toluene), sodium/benzophenone (THF), or
calcium hydride (acetonitrile and 1,2-dichloroethane) under nitrogen
before use. The 31P NMR spectra were recorded on Jeol FX90Q,
Jeol Eclipse 300, and Bruker AMX360 spectrometers operating at
36.23, 121.7, and 145.8 MHz, respectively, and referenced to 85%
1
CO, 20 °C}: δ 88.1 (s, CH), 78.6 (s, CH), 24.2 (d, JC,P ) 24.2
Hz, CH2), 21.1 (t, 1,2JC,P ) 14.1 Hz, CH2), 19.6 (m, CH2), 16.9 (s,
1
H3PO4 (δ ) 0 ppm). H (400.13 MHz) and 13C{1H) (100 MHz)
1
CH2), 8.7 (d, JC,P ) 8.0 Hz, CH2), 7.0 (s, CH3), 0.02 (s, CH3Si)
NMR spectra were obtained using a Bruker DPX400 spectrometer
and referenced to tetramethylsilane (δ ) 0 ppm). Infrared spectra
were recorded as KBr disks on a Nicolet 510 FT-IR spectropho-
tometer. Mass spectra were obtained on a VG Fisons Platform II
spectrometer. [(η5-Me3SiCp)Fe(CO)2(MeCN)]PF6 and related pre-
cursor complexes were prepared as detailed previously.6c
(Acetonitrile)(η5-trimethylsilylcyclopentadienyl){1,3-bis(phos-
phino)propane}iron(II) Hexafluorophosphate, 1. A solution of
[(η5-Me3SiCp)Fe(CO)2(MeCN)]PF6 (1.0 g, 2.3 mmol) in acetonitrile
(100 mL) was irradiated for 24 h using a 125 W Hanovia UV lamp.
The dark brown solution was filtered and a 10% w/v solution of
ppm. MS (APCI), m/z: 415 (20) [{η5-(Me3Si)Cp}FeL]+. Anal.
Calcd for C17H34P4F6SiFe (%): C, 36.44; H, 6.13. Found: C, 36.1;
H, 6.0. IR (KBr): 2319 m (νPH).
(η5-Trimethylsilylcyclopentadienyl)(1,4,8-triethyl-1,4,8-triph-
osphacyclodecane)iron(II) Hexafluorophosphate, 6. A solution
of 5 (0.5 g, 8.9 × 10-4 mol) in 20 mL of THF was cooled to -78
°C and stirred. To this yellow solution was added potassium tert-
butoxide (0.2 g, 1.78 mmol) and stirred at this temperature for 10
min until the solution had deepened to a red color. The solution
was then allowed to warm to room temperature while stirring, after

Iron(II) Complexes of Triphosphamacrocycles
Organometallics, Vol. 26, No. 2, 2007 385
which time it was cooled again to -78 °C, and bromoethane (0.2
mL, 2.68 mmol) was added. The mixture was allowed to warm to
room temperature and stirred overnight. The yellow-brown solution
was filtered and washed with THF, and the solvent was removed
in vacuo. The brown solid was redissolved in dichloromethane and
column chromatographed on neutral alumina, the yellow fraction
being collected and the solvent removed in vacuo. Crystals suitable
for X-ray crystallography were grown from cooling a solution of
the complex in methanol. Yield: 66 mg (12%). 31P{1H} NMR
{36.23 MHz, (CD3)2CO, 20 °C}: δ 134.7 (t, 2JP,P ) 36 Hz), 84.7
a dark yellow solid. 31P{1H} NMR (CDCl3, 36.23 MHz): δ 46.1
(t, 53 Hz)), 13.2 (d, 53 Hz) ppm. The dry solid was dissolved in
toluene (200 mL) containing AIBN (50 mg), and the mixture was
heated at 80 °C for 72 h. The volatile materials were removed in
vacuo, and the dark residue was dissolved in a small quantity of
dichloromethane and applied to a basic alumina column (1 × 10
cm). After washing the column with dichloromethane (100 mL), a
mixture of the desired compound and some minor unknowns was
eluted as a yellow band with 0.2% methanol in CH2Cl2 as eluant.
The resultant yellow solid was rechromatographed as above to give
the pure complex, which was converted to the hexfluorophosphate
salt by dissolution in methanol (2 mL) and addition of solid
ammonium hexafluorophosphate (300 mg). After adding 0.2 mL
of water, the solution was left at 4 °C overnight to give yellow
10b as a microcystalline solid, which was filtered, washed sparingly
with cold aqueous methanol, and dried in vacuo. Yield: 200 mg
(33%). 31P{1H} NMR (145.8 MHz, CDCl3, 20 °C): δ 114.8 (t,
2
1
(d, JP,P ) 36 Hz) ppm. H NMR (300 MHz, CDCl3, 20 °C): δ
4.39 (br, 2H, CpH), 4.24 (br, 2H, CpH), 2.6-2.0 (m, 8H), 2.0-
1.5 (m, 7H), 1.4-0.9 (m, 12H), 0.24 (s, 9H) ppm. 13C{1H) NMR
(75.6 MHz, CDCl3, 20 °C): δ 91.0 (s, CH), 74.9 (s, CH), 30.4
(dd, 1JC,P ) 30 Hz, 2JC,P ) 3.7 Hz, CH2), 27.5 (t, 1,2JC,P ) 13.9 Hz,
1,2
1
CH2), 26.7 (t,
J
) 13.9 Hz, CH2), 25.1 (d, JC,P ) 27.8 Hz,
C,P
CH2), 22.6 (q,1,2JC,P ) 13.9 Hz, CH2), 18.8 (s, CH2), 9.4 (d, JC,P
) 8.3 Hz, CH3), 8.39 (s, CH3), 0.94 (s, CH3) ppm. MS (APCI),
m/z: 471 (100) [{η5-(Me3Si)Cp}FeL]+. Anal. Calcd for C21H42P4F6-
SiFe (%): C, 40.91; H, 6.88. Found: C, 40.9; H, 6.8. IR (KBr):
2316 m (νPH).
2
2
2
2JP,P ) 30 Hz), 68.1 (dd, JP,P ) 54, 26 Hz), 66.8 (dd, JP,P ) 54,
1
3
30 Hz) ppm. H NMR (CDCl3, 400 MHz): δ 7.32 (t, JH,H ) 7.1
Hz, 2H, Ph), 7.27 (d, 3JH,H ) 7.1 Hz, 1H, Ph), 6.92 (d, 3JH,H ) 7.1
Hz, 2H, Ph), 5.17 (d br, 1JH,P ) 340 Hz, 1H, PH), 5.15 (d br, 1JH,P
) 350 Hz, 1H, PH), 3.16 (dd, 2JH,H ) 14.2 Hz, 2JH,P ) 5.4 Hz, 1H,
(η5-Pentamethylcyclopentadienyl)(diallylphenylphosphine)-
(1,2-diphosphino-ethane)iron(II) Tetrafluoroborate, 8a. To a
solution of 76b (1.0 g, 2.42 mmol) in 1,2-dichloroethane (50 mL)
was added diallylphenylphosphine (0.5 mL, 2.55 mmol), and the
mixture was heated at 80 °C for 2 h. After cooling, the solvent
was evaporated in vacuo to give a dark yellow oil, which was used
without further purification in the synthesis of 10a. Yield: 1.35 g
(99%). 31P{1H} NMR (36.23 MHz, CH2Cl2): δ 45.4 (t, 2JP,P ) 51
2
2
PhCH2), 2.87 (dd, JH,H ) 14.2 Hz, JH,P ) 5.4 Hz, 1H, PhCH2),
3
2.7-0.2 (m, 13H), 1.73 (s, 15H, CpCH3), 1.36 (dd, JH,P ) 12.2
Hz, JH,H ) 5.0 Hz, 3H, CH3) ppm. 13C{1H) NMR (100 MHz,
3
2
CDCl3, 20 °C): δ 134.3 (d, JC,P ) 7.0 Hz, C), 130.6 (s, CH),
129.7 (s, CH), 127.8 (s, CH), 127.8 (s, CH), 89.4 (s, C), 37.0 (dd,
1JC,P ) 8.9 Hz, JC,P ) 6.3 Hz, CH2), 34.5 (dd, JC,P ) 27.9 Hz,
2
1
2JC,P ) 16.2 Hz, CH), 30.0 (dd, JC,P ) 28.3 Hz, JC,P ) 14.3 Hz,
1
2
1
2
2
CH2), 22.7 (dd, JC,P ) 25.7 Hz, JC,P ) 7.0 Hz, CH2), 22.3 (dd,
Hz), 11.9 (d, JP,P ) 51 Hz) ppm.
1JC,P ) 22.9 Hz, JC,P ) 6.4 Hz, CH2), 20.0 (dd, JC,P ) 30.1 Hz,
2
1
rac-(η5-Pentamethylcyclopentadienyl)(1-phenyl-3-methyl-1,4,7-
triphospha-cyclodecane)iron(II) Hexafluorophosphate, 10a. A
solution of 8a (1.35 g, 2.41 mmol) in toluene (200 mL) containing
azoisobutyronitrile (∼0.2 g) was heated at 90 °C for 8 h. After
cooling, volatile materials were removed in vacuo, and the dark
residue was dissolved in a small quantity of dichloromethane and
applied to a basic alumina column (5 × 3.5 cm). The desired
compound was eluted as a yellow band with 0.5% methanol in
CH2Cl2 as eluant. The solution was dried over MgSO4 and filtered,
and the volatiles were removed to give an orange solid. This was
dissolved in methanol (5 mL) and solid ammonium hexafluoro-
phosphate (300 mg) added thereto. After leaving at 4 °C overnight
yellow acicular crystals of 10a had precipitated. These were filtered
off, washed sparingly with cold methanol, and dried in vacuo.
Yield: 500 mg (33%). 31P{1H} NMR {36.23 MHz, CDCl3, 20
°C}: δ 111.7 (t, 2JP,P ) 25 Hz), 65.7 (dd, 2JP,P ) 54, 25 Hz), 61.7
(dd, 2JP,P ) 54, 25 Hz) ppm. 1H NMR {400 MHz, CDCl3, 20 °C}:
2JC,P ) 17.0 Hz, CH2), 19.6 (dd, JC,P ) 26.9 Hz, JC,P ) 7.2 Hz,
1
2
3
2
CH2), 18.7 (s, CH2), 18.1 (dd, JC,P ) 16.9 Hz, JC,P ) 6.9 Hz,
CH3), 10.4 (s, CH3) ppm. MS (APCI), m/z: 475 (100) [(η5-C5-
Me5)FeL]+. Anal. Calcd for C24H38P4F6Fe (%): C, 46.46; H, 6.19.
Found: C, 46.0; H, 6.3. IR (KBr): 2316 m (νPH).
rac-(η5-Pentamethylcyclopentadienyl)(4,7-dichloro-1-phenyl-
3-methyl-1,4,7-triphosphacyclodecane)iron(II) Hexafluorophos-
phate, 11a. A solution of 10a (50 mg, 8.1 × 10-5 mol) in
dichloromethane (5 mL) was stirred with a 10% aqueous solution
of sodium hydroxide for 1 h. The organic phase was isolated,
washed with water (3 × 2 mL), and dried over MgSO4. After
filtering, the solvent was removed to yield an orange solid. Yield:
95%. 31P{1H} NMR (145.8 MHz, CDCl3, 20 °C): δ 222.6 (dd,
2
2JP,P ) 8.2, 6.0 Hz), 202.5 (dd, JP,P ) 13.8, 8.2 Hz), 59.8 (dd,
2JP,P ) 13.8, 6.0 Hz) ppm. 1H NMR (400 MHz, CDCl3, 20 °C): δ
7.41 (t, 3JH,H ) 7.1 Hz, 2H, Ph), 7.21 (d, 3JH,H ) 7.1 Hz, 2H, Ph),
7.10 (d, 3JH,H ) 7.1 Hz, 1H, Ph), 3.3-1.2 (m, 13H), 1.54 (dd obs,
3JH,P ) 14.0 Hz, 3JH,H ) 6.8 Hz, 3H, CH3), 1.46 (s, 15H, CpCH3)
ppm. MS (APCI), m/z: 509 (75) [(η5-C5Me5)FeL - Cl]+. Anal.
Calcd for C24H36P4Cl2F6Fe (%): C, 41.82; H, 5.28. Found: C, 42.0;
H, 5.3.
3
δ 7.38 (m, 3H, Ph), 7.22 (t, JH,H ) 6.1 Hz, 2H, Ph), 5.32 (d br,
1
1JH,P ) 342 Hz, 1H, PH), 5.15 (d br, JH,P ) 339 Hz, 1H, PH),
2.8-1.6 (m, 10H), 1.46 (dd, 3JH,P ) 12.2 Hz, 3JH,H ) 7.2 Hz, 3H,
CH3), 1.39 (s, 15H, CpCH3), 1.3-0.8 (m, 3H) ppm. 13C{1H) NMR
(100 MHz, CDCl3, 20 °C): δ 138.0 (d, 1JC,P ) 27.3 Hz, C), 130.6
2
3
rac-(η5-Pentamethylcyclopentadienyl)(4,7-dichloro-1-benzyl-
3-methyl-1,4,7-triphosphacyclodecane)iron(II) Hexafluorophos-
phate, 11b. A solution of 10b (50 mg, 8.1 × 10-5 mol) in
dichloromethane (5 mL) was stirred with a 10% aqueous solution
of sodium hydroxide for 1 h. The organic phase was isolated,
washed with water (3 × 2 mL), and dried over MgSO4. After
(d, JC,P ) 7.8 Hz, CH), 130.3 (s, CH), 129.2 (d, JC,P ) 8.0 Hz,
CH), 89.0 (s, C), 38.4 (dd, 1JC,P ) 20.3 Hz, 2JC,P ) 15.4 Hz, CH2),
36.4 (dd, 1JC,P ) 26.9 Hz, 2JC,P ) 14.4 Hz, CH), 25.0 (dd, 1JC,P
28.0 Hz, JC,P ) 6.9 Hz, CH2), 22.5 (dd, JC,P ) 26.8 Hz, JC,P
17.1 Hz, CH2), 19.6 (t,
14.0 Hz, CH2), 18.4 (dd, JC,P ) 15.9 Hz, JC,P ) 7.1 Hz, CH3),
18.1 (s, CH2), 10.1 (s, CH3). MS (APCI), m/z: 475 (100) [(η5-C5-
Me5)FeL]+. Anal. Calcd for C24H38P4F6Fe (%): C, 46.46; H, 6.19.
Found: C, 46.0; H, 6.3. IR (KBr): 2316 m (νPH).
)
)
)
2
1
2
1,2
1,2
J
) 13.7 Hz, CH2), 19.4 (t,
J
C,P
C,P
3
2
filtering, the solvent was removed to yield an orange solid. Yield:
2
92%. 31P{1H} NMR (145.8, CDCl3, 20 °C): δ 220.3 (dd, JP,P
)
)
2
2
15.8, 8.1 Hz), 203.5 (dd, JP,P ) 19.0, 8.1 Hz), 57.0 (dd, JP,P
rac-(η5-Pentamethylcyclopentadienyl)(1-benzyl-3-methyl-1,4,7-
triphospha-cyclodecane)iron(II) Hexafluorophosphate, 10c. To
a solution of 7 (600 mg, 1.47 mmol) in 1,2-dichloroethane (10 mL)
was added benzyldiallylphosphine (0.35 mL, 1.71 mmol), and the
solution was heated at 70 °C for 3 h. After cooling, the mixture
was filtered and the solvents were removed in vacuo to give 8b as
19.0, 15.8 Hz) ppm. 1H NMR (CDCl3, 400 MHz): δ 7.30 (t, 3JH,H
) 7.1 Hz, 2H, Ph), 7.25 (d, 3JH,H ) 7.1 Hz, 1H, Ph), 6.94 (d, 3JH,H
) 7.1 Hz, 2H, Ph), 3.29 (dd, 2JH,H ) 14.4 Hz, 2JH,P ) 6.2 Hz, 1H,
2
2
PhCH2), 2.93 (dd, JH,H ) 14.4 Hz, JH,P ) 6.2 Hz, 1H, PhCH2),
3
2.7-0.2 (m, 13H), 1.82 (s, 15H, CpCH3), 1.47 (dd, JH,P ) 14.0
Hz, JH,H ) 7.1 Hz, 3H, CH3). MS (APCI), m/z: 524 (80) [(η5-
3

386 Organometallics, Vol. 26, No. 2, 2007
Battle et al.
Table 1. X-ray Data Collection and Refinement Parameters.
6
10a
14
empirical formula
fw
C21H42P4F6SiFe
616.37
C24H38F6P4Fe
620.27
C25H36P4F6Fe
630.27
temp, K
cryst syst
space group
a/Å
b/Å
c/Å
293
monoclinic
P2(1)/n
10.9946(5)
16.3024(7)
16.0530(7)
102.311(2)
293
hexagonal
R3h
42.467(6)
42.467(6)
9.690(2)
150
orthorhombic
P2(1)2(1)2(1)
9.0310(2)
15.2330(3)
19.7330(4)
â/deg
γ/deg
120
15134(4)
18
1.225
U/Å3
2811.1(2)
4
1.456
2714.65(10)
4
1.542
1304
Z
Dc/Mg m-3
F(000)
1288
5796
cryst size/mm
θ range/deg
index ranges
0.15 × 0.15 × 0.10
3.13 to 25.45
-13 e h e 13,
-19 e k e 19,
-18 e l e 19
17 383
0.25 × 0.20 × 0.16
2.17 to 27.50
-54 e h e 52,
-54 e k e 48,
-12 e l e 12
28 355
0.05 × 0.10 × 0.15
3.65 to 27.48
-11 e h e 11,
-19 e k e 19,
-25 e l e 25
27 972
no. of reflns collected
no. of indep reflns
Rint
5143
0.1584
7692
0.0939
6202
0.0826
no. of data/restraints/params
absorp corr, µ
5143/0/304
0.856
1.061
0.0591, 0.1183
0.0814, 0.1290
0.754 and -0.522
7692/71/363
0.683
1.080
0.0771, 0.2155
0.1045, 0.2286
1.404 and -0.757
6202/0/326
0.847
1.065
0.0403, 0.0875
0.0602, 0.0955
0.427 and -0.338
goodness of fit on F2
final R1, wR2 [I > 2σ(I)]
(all data)
largest diff peak and hole/e Å-3
C5Me5)FeL - Cl]+. Anal. Calcd for C25H38P4Cl2F6Fe (%): C,
42.69; H, 5.46. Found: C, 42.2; H, 5.3.
C), 37.4 (m, CH2), 27.3 (m, CH2), 25.9 (m, CH2), 24.4 (m, CH2),
18.8 (m, CH2) ppm. MS (APCI), m/z: 485 (100) [(η5-Cp)FeL]+.
X-ray Crystallography. Crystallographic measurements were
performed on a Bruker Nonius kappa CCD area detector using
monochromated Mo KR radiation (λ ) 0.71073 Å). The structures
(Acetonitrile)(η5-cyclopentadienyl){1,2-bis(diallylphosphino)-
ethane}iron(II) Hexafluorophosphate, 12. To a solution of [(η5-
C5H5)Fe(η6-C6H6)]PF6 (1 g, 2.92 mmol) in acetonitrile (100 mL)
was added 1,2-bis(diallylphosphino)ethane (0.74 g, 2.92 mmol),
and the solution was irradiated for 12 h using a 100 W visible lamp.
The solvent was removed in vacuo to give the desired compound
as a red solid. Yield: 1.99 g (82%). 31P{1H} NMR (145.8 MHz,
CD3CN, 20 °C): δ 89.3 (s) ppm. 1H NMR (400 MHz, CD3CN, 20
°C): δ 5.90 (m, 4H, CH:CH2), 5.20 (m, 8H, CH:CH2), 4.39 (s br,
CpH), 2.30 (s, CH3CN), 2.80 (m, 4H, CH2), 1.70 (m, 8H, CH2)
ppm. 13C{1H) NMR (100 MHz, CD3CN, 20 °C): δ 130.2 (m, CH:
CH2), 118.4 (d, CH:CH2), 32.7 (m, CH2), 30.4 (m, CH2), 22.4 (m,
CH2) ppm. MS (APCI), m/z: 375 (50) [(η5-Cp)FeL - MeCN]+.
IR (KBr): 2278 cm-1 (νCN).
2
were solved by direct methods (SHELXS-96)10 and refined on Fo
by full-matrix least-squares (SHELXL-97)11 using all the unique
data. Empirical absorption corrections were carried out by the
XABS12 and DIFABS13 methods. The non-hydrogen atoms were
refined anisotropically. Figures were produced using ORTEP-3 for
Windows version 1.0814 and PovRay for Windows version 3.5.15
The crystal data and refinement details are summarized in Table
1.
Acknowledgment. We thank the EPSRC for funding (GR/
N06076/01, A.R.B.) and studentship support (R.H., S.M.L.).
(η5-Cyclopentadienyl)(1-phenyl-5,8-diallyl-1,5,8-triphosphacy-
cloundecane)-iron(II) Hexafluorophosphate, 14. To a solution
of 12 (0.60 g, 1.07 mmol) in dichloromethane (50 mL) was added
phenylphosphine (0.12 g, 1.07 mmol), and the red solution was
stirred at room temperature for 2 weeks. The yellow solution was
evaporated to dryness in vacuo to give a yellow solid, which was
recrystallized from THF. Yield: 35 mg (5%). 31P{1H} NMR (121.7
Supporting Information Available: Crystallographic data
(CIF) are available free of charge via the Internet at http://
pubs.acs.org.
OM060798G
(10) Sheldrick, G. M. Acta Crystallogr. 1990, A46, 467.
(11) Sheldrick, G. M. SHELX-97, program for crystal structure refine-
ment; University of Gottingen: Germany, 1997.
(12) Parkin, S.; Moezzi, B.; Hope, H. J. Appl. Crystallogr. 1995, 28,
53.
(13) Walker, N.; Stuart, D. Acta Crystallogr., Sect. A 1983, 39, 158.
(14) Farrugia, L. J. J. Appl. Crystallogr. 1997, 30, 565.
(15) Persistence of Vision Raytracer; Pty Ltd; Williamstown, Victoria,
Australia, HTTP://www.povray.org.
2
2
MHz, CD3CN, 20 °C): δ 81.0 (d, JP,P ) 63 Hz), 37.9 (t, JP,P
)
63 Hz) ppm. 1H NMR (400 MHz, CDCl3, 20 °C): δ 7.58 (m, 3H,
Ph), 7.46 (m, 2H, Ph), 5.90 (m, 2H, CH:CH2), 5.21 (m, 4H, CH:
CH2), 4.20 (s br, 5H, Cp-H), 2.8 (m, 8H, CH2), 2.7 (m, 4H, CH2),
2.2 (m, 4H, CH2), 1.8 (m, 4H, CH2) ppm. 13C{1H} NMR (100 MHz,
CD3CN, 20 °C): δ 143.4 (d, C), 130.5 (s, CH), 129.5 (s, CH),
128.6 (s, CH), 128.0 (m, CH:CH2), 118.0 (m, CH:CH2), 81.0 (s,