Transition metal stannyl complexes. 11.1 Chelated ((phosphinoalkyl)stannyl)iron complexes by intramolecular oxidative addition of tin-phenyl or tin-methyl groups

Article abstract of DOI:10.1021/om960424v

Reaction Of Fe₂(CO)₉ with Ph₂P(CH₂)_nSnR₂R' (n = 2, R' = Ph, SnR₂ = SnPh₂, SnPhMe, R' = Me, SnR₂ = SnMe₂; n = 1, 3, SnR₂R' = SnPh₃) results in the formation of (CO)_5-xFe[PPh₂(CH₂)_nSnR ₂R']_x (x = 1, 2). Upon UV irradiation, the chelated (phosphinoalkyl)-stannyl complexes (CO)₃(R')FePPh₂(CH₂)_nSnR₂ are obtained by intramolecular oxidative addition of the Sn-R' group. The complexes mer-(CO)₃(H)(R'₃Si)FePPh₂(CH2) ₃SnPh₃ (SiR'₃ = SiMePh₂, Si(OMe)₃) are formed at -50°C from (CO)₄Fe(H)SiR'₃ and Ph₂P(CH₂)₂SnPh₃. While the SiMePh₂ derivative is converted to the chelated complex (CO)₃(Ph)FePPh₂-(CH₂)₂SnPh ₂ by HSiMePh₂ elimination upon heating, the Si(OMe)₃ derivative does not give the intramolecular oxidative addition. Photochemical reaction of (CO)₃(Ph)FePPh₂-(CH₂)₂SnPh ₂ with Ph₂P(CH₂)₂SnPh₃ gives the substitution product (CO)₂(Ph)Fe[PPh₂-(CH₂)₂SnPh ₂]PPh₂(CH₂)₂SnPh₃. While a second oxidative addition to the iron center by the dangling SnPh₃ group is not possible, the Sn-Ph group readily adds to a (Ph₃P)₂Pt fragment to give (CO)₂(Ph)Fe[PPh₂(CH₂)₂SnPh ₂]PPh₂(CH₂)₂SnPh ₂Pt(Ph)(PPh₃)₂. The related complex il - (CO)₃(H)[(MeO)₃Si]FePPh₂(CH₂) ₂SnPh₂Pt(Ph)(PPh₃)₂ is similarly obtained from (CO)₃(H)[(MeO)₃-Si]FePPh₂(CH₂) ₂SnPh₃.

Full text of DOI:10.1021/om960424v

Organometallics 1996, 15, 4707-4713
4707
Tr a n sition Meta l Sta n n yl Com p lexes. 11.1 Ch ela ted
((P h osp h in oa lk yl)sta n n yl)ir on Com p lexes by
In tr a m olecu la r Oxid a tive Ad d ition of Tin -P h en yl or
Tin -Meth yl Gr ou p s
Ulrich Schubert*,2a,b and Stefanie Grubert2b
Institut fu¨r Anorganische Chemie, Technische Universita¨t Wien, Getreidemarkt 9,
A-1060 Wien, Austria, and Institut fu¨r Anorganische Chemie, Universita¨t Wu¨rzburg,
Am Hubland, D-97074 Wu¨rzburg, Germany
Received May 30, 1996X
Reaction of Fe2(CO)9 with Ph2P(CH2)nSnR2R′ (n ) 2, R′ ) Ph, SnR2 ) SnPh2, SnPhMe, R′
) Me, SnR2 ) SnMe2; n ) 1, 3, SnR2R′ ) SnPh3) results in the formation of
(CO)5-xFe[PPh2(CH2)nSnR2R′]x (x ) 1, 2). Upon UV irradiation, the chelated (phosphinoalkyl)-
stannyl complexes (CO)3(R′)FePPh2(CH2)nSnR2 are obtained by intramolecular oxidative
addition of the Sn-R′ group. The complexes mer-(CO)3(H)(R′3Si)FePPh2(CH2)3SnPh3 (SiR′3
) SiMePh2, Si(OMe)3) are formed at -50 °C from (CO)4Fe(H)SiR′3 and Ph2P(CH2)2SnPh3.
While the SiMePh2 derivative is converted to the chelated complex (CO)3(Ph)FePPh2-
(CH2)2SnPh2 by HSiMePh2 elimination upon heating, the Si(OMe)3 derivative does not give
the intramolecular oxidative addition. Photochemical reaction of (CO)3(Ph)FePPh2-
(CH2)2SnPh2 with Ph2P(CH2)2SnPh3 gives the substitution product (CO)2(Ph)Fe[PPh2-
(CH2)2SnPh2]PPh2(CH2)2SnPh3. While a second oxidative addition to the iron center by the
dangling SnPh3 group is not possible, the Sn-Ph group readily adds to a (Ph3P)2Pt fragment
to give (CO)2(Ph)Fe[PPh2(CH2)2SnPh2]PPh2(CH2)2SnPh2Pt(Ph)(PPh3)2. The related complex
(CO)3(H)[(MeO)3Si]FePPh2(CH2)2SnPh2Pt(Ph)(PPh3)2 is similarly obtained from (CO)3(H)[(MeO)3-
Si]FePPh2(CH2)2SnPh3.
The electronic and steric factors governing the oxida-
tive addition of E-H groups (E ) Si, Ge, Sn) to
transition metal centers were intensively investigated
and are well understood. Contrary to this, the oxidative
addition of R3E-E′R′3 (E′ ) main group 4 element)3 has
only recently gained increased attention. While E-H
groups are readily added to a large number of metal
complex fragments, the electronic and steric require-
ments are more stringent for the addition of R3E-E′R′3.
Unactivated Sn-C bonds, such as Sn-Ph or Sn-Me,
are readily added to [(Ph3P)2Pt], for example, to give
the complexes cis-(Ph3P)2Pt(R′)SnR34 but are not added
to less reactive metal complex fragments, such as [(CO)4-
Fe]. The formation of [(CO)4Fe(µ-SnR2)]2 from iron
carbonyls and tetraorganostannanes SnRxR′4-x was only
observed for special groups R′ and special combinations
of R and R′.5
Si-H bonds of R2P(CH2)nSiR′2H.6 Facilitated oxidative
addition of Si-Si bonds was recently also observed for
Ph2P(CH2)2-substituted disilanes (Ph2P(CH2)2SiMe2-
7
8
SiR3 and [Ph2P(CH2)2SiMe2]2 ). The corresponding
distannanes, [Ph2P(CH2)nSnMe2]2, were earlier used for
the preparation of chelated (phosphinoalkyl)stannyl
complexes of Pt(II).9 Chelate-assisted oxidative addi-
tions of Sn-C bonds to Pd and Pt centers were earlier
reported by us.10 In the present paper we describe the
oxidative addition of Sn-Me or Sn-Ph bonds of Ph2P-
(CH2)nSnR3 to the less reactive [Fe(CO)4] fragments. A
preliminary report was published earlier.11
Resu lts a n d Discu ssion
Previous experiments of Grobe and Mo¨ller had shown
that thermal reaction (160 °C) of Fe(CO)5 or Fe2(CO)9
with Me2PCH2CH2SnMe3 results in the formation of
both the monophosphane complex (CO)4FePMe2CH2-
Apart from electronic and steric factors, oxidative
addition reactions are promoted by “chelate assistance”,
as has initially been shown by Stobart et al. for the
(6) For example: Holmes-Smith, R. D.; Stobart, S. R.; Cameron, T.
S.; J ochem, K. J . Chem. Soc., Chem. Commun. 1981, 937. Auburn,
M. J .; Stobart, S. R. Inorg. Chem. 1985, 24, 318. Grundy, S. L.;
Holmes-Smith, R. D.; Stobart, S. R.; Williams, M. A. Inorg. Chem. 1991,
30, 3333.
X Abstract published in Advance ACS Abstracts, October 1, 1996.
(1) Part 10: Seebald, S.; Kickelbick, G.; Mo¨ller, F.; Schubert, U.
Chem. Ber. 1996, 129, 1131.
(2) (a) Technische Universita¨t Wien. (b) Universita¨t Wu¨rzburg.
(3) Schubert, U. Angew. Chem. 1994, 106, 435; Angew. Chem., Int.
Ed. Engl. 1994, 33, 419.
(4) Butler, G.; Eaborn, C.; Pidcock, A. J . Organomet. Chem. 1979,
181, 47. Eaborn, C.; Pidcock, A.; Steele, B. R. J . Chem. Soc., Dalton
Trans. 1976, 767.
(7) Gilges, H.; Schubert, U. J . Organomet. Chem., submitted for
publication.
(8) Murakami, M.; Yoshida, T.; Ito, Y. Organometallics 1994, 13,
2900. Murakami, M.; Yoshida, T.; Ito, Y. Chem. Lett. 1996, 13.
(9) Weichmann, H. J . Organomet. Chem. 1982, 238, C49.
(10) Mu¨ller, C.; Schubert, U. Chem. Ber. 1991, 124, 2181.
(11) Schubert, U.; Grubert, S.; Schulz, U.; Mock, S. Organometallics
1992, 11, 3165.
(5) King, R. B.; Stone, F. G. A. J . Am. Chem. Soc. 1960, 82, 3833.
Ibekwe, S. D.; Newlands, M. J . J . Chem. Soc. A 1967, 1783.
S0276-7333(96)00424-4 CCC: $12.00 © 1996 American Chemical Society

4708 Organometallics, Vol. 15, No. 22, 1996
Schubert and Grubert
CH2SnMe3 and the bis(phosphane) complex (CO)3Fe-
(PMe2CH2CH2SnMe3)2.12 When we reacted a toluene
solution of Fe2(CO)9 with the derivatives Ph2PCH2CH2-
SnR2R′ (SnR2R′ ) SnPh3, SnPh2Me, SnMe3) in a 2:1
ratio, we got not only the corresponding phosphane
complexes 1a -c and 2a -c but in each case also minor
amounts of a third metal complex, which turned out to
be the oxidative addition products 3a -c (eq 1). When
a 1:1 ratio of the reactants was employed, a considerable
amount of Ph2PCH2CH2SnR2R′ remained unreacted and
had to be separated from the reaction mixture by
reaction with Mel and precipitation of the phosphonium
salt.
with Ph2PCH2CH2SnR2R′ after removal of the bis-
(phosphane) complexes (2b,c) by column chromatogra-
phy.
The complexes 3 are the intramolecular oxidative
addition products of a Sn-Ph or Sn-Me group to the
iron center of coordinatively unsaturated [(CO)3FePPh2-
CH2CH2SnR2R′]. The latter compound is obviously
photochemically formed from either 2 (abstraction of a
phosphane ligand) or 1 (abstraction of a CO ligand). The
formation of 3b shows, as expected,4 that oxidative
addition of a Sn-Ph bond is more favorable (for elec-
tronic reasons) than that of a Sn-Me bond. We cannot
rule out that there is also oxidative addition of the Sn-
Me bond to a minor extent, because we observed an
additional minor signal at 75.2 ppm in the 31P NMR
spectrum of the reaction mixture of Fe2(CO)9 with Ph2-
PCH2CH2SnMePh2, which could be due to the Fe-Me
isomer. The preparation of 3c shows that the iron
center, in principle, is reactive enough for the chelate-
assisted oxidative addition of a Sn-Me group.
The thermal stability of 3 depends to a very high
degree on the substituents at tin. While 3a ,b are
remarkably stable against reductive elimination, even
at elevated temperatures, 3c is very labile and com-
pletely decomposes already at -25 °C within 24 h. The
main decomposition product is Ph2PCH2CH2SnMe3,
formed by initial reductive elimination of the Sn-Me
bond. Since oxidative addition and reductive elimina-
tion are reverse processes, the facile elimination of the
Sn-Me group in 3c is consistent with the less pro-
nounced tendency to oxidatively add to the metal,
compared with Sn-Ph groups.
The bis(phosphane) complexes 2a -c were isolated by
column chromatography, while the mono(phosphane)
complexes 1a -c and the oxidative addition products
3a -c were eluted in one zone. We separated the SnPh3
derivative 1a , which was obtained as a yellow powder
being stable in air for a short time. The complexes 2
are slightly less soluble in hydrocarbons than 1. The
IR and NMR spectra of 1 are typical for trigonal-
bipyramidal (CO)4FeL complexes with an axial ligand
L. The 31P{1H} NMR spectra of 2 show a signal at 80.5
ppm (2a ) or 80.6 ppm (2c) for the chemically equivalent
phosphorus nuclei. Due to the different tin isotopes,
We also probed the effect of the ring size on the
oxidative addition by thermally reacting Ph2PCH2SnPh3
and Ph2PCH2CH2CH2SnPh3 with Fe2(CO)9. Reaction
of Ph2PCH2CH2CH2SnPh3 proceeded as that of Ph2-
PCH2CH2SnPh3; i.e., the phosphane complexes 1e and
2e and the oxidative addition product 3e were formed.
Thermal reaction of Ph2PCH2SnPh3 with Fe2(CO)9 only
yielded the mono(phosphane) complex 1d . Toluene
solutions of the isolated complexes 1d and 1e were
irradiated by UV light. The oxidative addition product
3e was formed from 1e within 3 h in high yields. There
was no significant difference to the reaction of 1a , and
particularly no indication for the oxidative addition of
the Sn-CH2 bond (which would have resulted in a five-
membered Fe-P-C-C-C metallacycle and a SnPh3
ligand). Contrary to that, the reaction of 1d was less
straightforward. There was no further change in the
IR spectrum of the reaction mixture after 7 h of
irradiation, although some starting compound was left.
This indicates an equilibrium between the oxidative
addition and reductive elimination products. The 31P
NMR spectrum showed that the oxidative addition
product 3d was formed, but there was also a great
number of byproducts. This is not unexpected, because
the formation of a four-membered metallacycle is less
favorable than of five- or six-membered ones. The same
trend has been observed for the tendency to form chelate
complexes of nickel with Ph2P(CH2)nPPh2 (n ) 1 , n )
2 ≈ n ) 3).13
2
ABX-type spectra were observed, with a J PFeP coupling
constant of 31 Hz for 2a . A similar value (32 Hz) was
previously observed for trans-(CO)3Fe(PPh3)(PMePh2).
Therefore, the complexes 2 also have the trans-geom-
etry, although the appearance of one weak and two
strong ν(CO) bands of equal intensity [2a , 1940 (w),
1882 (s), 1876 (s) cm-1; 2c, 1939 (w), 1884 (s), 1872 (s)
cm-1] indicates that the trigonal-bipyramidal geometry
is severely distorted.
For the deliberate synthesis of 3a , a toluene solution
of the mono(phosphane) complex 1a was irradiated with
UV light. There was quantitative conversion of 1a after
2 h. The synthesis of 3a was then simplified by
irradiating the mixture of complexes obtained by the
thermal reaction of Fe2(CO)9 with Ph2PCH2CH2SnPh3
(2:1 ratio) after removal of unreacted Fe2(CO)9. Within
a few hours the IR bands of 2a disappeared. Irradiation
was continued until 1a was also consumed. This
procedure gives 3a in a higher overall yield (71%) and
does not require the separation of 1a from the byprod-
ucts. The chelate complexes 3b,c were similarly pre-
pared by irradiating the reaction mixtures of Fe2(CO)9
The complexes 3 were isolated as yellow solids, soluble
in common organic solvents. The ν(CO) bands in the
infrared spectra show the mer arrangement of the three
(12) Grobe, J .; Mo¨ller, U. J . Organomet. Chem. 1972, 36, 335.
(13) Tolman, C. A. Chem. Rev. 1977, 77, 313.

Transition Metal Stannyl Complexes
Organometallics, Vol. 15, No. 22, 1996 4709
CO ligands. This requires the phenyl or methyl group
cis to Sn (trans to P), as expected for oxidative addition
products. Bonding of one phenyl (methyl) group to the
iron atom in 3 results in a high-field shift of the
Oxidative addition of the Sn-Ph bond of 4a to the
iron center requires reductive elimination of the silane.
The ready formation of 3a shows that readdition of the
silane to the vacant coordination site is less favorable
than addition of the Sn-C bonds. The oxidative addi-
tion of Si-H bonds usually is much more favored than
that of Sn-C bonds. In the present case the situation
is obviously reversed by the chelate assistance of the
Sn-C addition.
It is known that reductive elimination of silanes is
rendered more difficult if the silicon atom is substituted
by electronegative groups. When (CO)4Fe(H)Si(OMe)3
and Ph2PCH2CH2SnPh3 were reacted under the same
conditions as the SiMePh2 derivative, the ready forma-
tion of the phosphane-substituted complex 4b was
observed, but there was no indication for the subsequent
formation of 3a (eq 2). Compared with the SiMePh2
derivative 4a , the situation is reversed; i.e., oxidative
addition of HSi(OMe)3 is preferred to that of Sn-Ph
(despite chelate assistance), or there is a high barrier
for the reductive elimination of HSi(OMe)3 which pre-
vents vacation of the coordination site. Complex 4b is
stable and was fully characterized. The spectra are
similar to those of 4a and typical for a complex of the
type mer-(CO)3(R′3P)Fe(H)SiR3, with the hydrogen atom
cis to both the SiR3 and the PR3 ligand.15
To probe the possibility of a double oxidative addition
(as has been observed for Pt and Pd complexes10), a
toluene solution of 2a was also irradiated by UV light.
The IR and 31P NMR spectra showed no signals of 2a
after 2 h but instead those of 3a , a new complex 5, and
uncoordinated Ph2PCH2CH2SnPh3. The portion of 5
was considerably increased when Fe2(CO)9 was first
thermally reacted with a 4-fold excess of Ph2PCH2CH2-
SnPh3 and then irradiated with UV light (as previously
discussed for the preparation of 3a except for the
different Fe2(CO)9:ligand ratio). After 7 h of irradiation,
the IR bands of 1a and 2a were no longer observed, and
the main product was 3a , besides a small amount of 5.
Irradiation for an additional 12 h resulted in the nearly
complete conversion of 3a into 5. This observation is
an additional indication that formation of 5 from 2a does
proceed via elimination of one phosphane ligand (as
discussed before), formation of 3a , and readdition of the
phosphane ligand (eq 3). The proposed formation of 5
from 3a was confirmed by another experiment, in which
isolated 3a was irradiated with an equimolar amount
of Ph2PCH2CH2SnPh3. Only 5 was formed. As in the
case of 3a , the “direct” synthesis of 5 (without isolation
of 2a or 3a ) is more convenient and results in a better
yield.
1
corresponding H NMR signals of about 0.5 (1.0) ppm
relative to 1 or 2. The 119Sn signal is shifted from 4.0
ppm in Ph2PCH2CH2SnPh3 to 137.5 ppm in 3a due to
the metal coordination. Formation of the five-mem-
bered chelate ring results in a strong decrease of the
3J SnCCP coupling constant, from 253/248/230 Hz in 1a -c
to about 70-75 Hz in 3a -c. The structure of 3a was
confirmed by an X-ray structure analysis which was
earlier reported.11 The structure of 3a is static (separate
signals for the equatorial and axial CO groups) up to
85 °C. The Sn-P coupling in the complexes 3a ,d ,e
shows the same trends (mixing of coupling “through the
metal” and “through the backbone”) as has been dis-
cussed for the P-P coupling in complexes with chelated
diphosphinoalkane ligands.14
The chelate complex 3a was also obtained in high
yields, when Ph2PCH2CH2SnPh3 was thermally reacted
with a toluene solution of the hydrido silyl complex cis-
(CO)4Fe(H)SiMePh2 (eq 2). Mixing of both compounds
at room temperature resulted in immediate CO evolu-
tion. Three signals were observed at 78.7 (strong
signal), 72.3, and 58.7 ppm in the 31P NMR spectrum
of the solution. They are attributed to 3a , 1a , and the
phosphane-substituted hydrido silyl complex 4a . The
latter value compares well with that of (CO)3(Ph3P)Fe-
(H)SiMePh2 (60.9 ppm).15 When the solution was
heated to 70 °C, only the bands of 3a were left in the
IR spectrum.
For the better characterization of 4a the reaction was
also performed at -50 °C. At this temperature the
subsequent reaction of 4a to 3 was slowed down.
Although this results in a higher 4a /3a ratio, the
complex 4a could not be isolated analytically pure due
to its high reactivity. Phosphane-substituted hydrido
silyl complexes of the type mer-(CO)3(R′3P)Fe(H)SiR3
Complex 5 was obtained as a yellow solid, soluble in
common organic solvents, except saturated hydrocar-
bons. There is only one ν(CO) band in the IR spectrum
of 5, which is consistent with a complex of the type
trans-(CO)2FeL4. There are two AB spin systems with
about equal intensity in the 31P NMR spectrum, each
of them accompanied by tin satellites. The AB system
with δ(P1) ) 74.8 ppm and δ(P2) ) 62.7 ppm is assigned
have been prepared by photochemical reaction of (CO)4-
15-17
(R′3P)Fe with HSiR3
or by thermal reaction of cis-
(CO)4Fe(H)SiR3 with PR′3.18,19 The latter reaction may
be complicated by deprotonation reactions (with basic
phosphanes) or silane elimination.
2
to 5a , because the J PFeP coupling constant of 57 Hz is
typical to trans phosphane ligands (for example, 79 Hz
(14) Grim, S. O.; Barth, R. C.; Mitchell, J . D.; DelGaudio, J . Inorg.
Chem. 1977, 16, 1776.
(15) Knorr, M.; Schubert, U. Transition Met. Chem. 1986, 11, 268.
(16) Liu, D. K.; Brinkley, C. G.; Wrighton, M. S. Organometallics
1984, 3, 1449. Brinkley, C.; Dewan, J . C.; Wrighton, M. S. Inorg. Chim.
Acta 1986, 121, 119.
(18) J etz, W.; Graham, W. A. G. Inorg. Chem. 1971, 10, 4. Bella-
chioma, G.; Cardaci, G. Inorg. Chem. 1982, 21, 3232. Bellachioma,
G.; Cardaci, G.; Colomer, E.; Corriu, R. J . P.; Vioux, A. Inorg. Chem.
1989, 28, 519.
(17) Knorr, M.; Schubert, U. J . Organomet. Chem. 1989, 365, 151.
(19) Knorr, M.; Mu¨ller, J .; Schubert, U. Chem. Ber. 1987, 120, 873.

4710 Organometallics, Vol. 15, No. 22, 1996
Schubert and Grubert
were found for (CO)2[P(OPh)3]2Fe(H)SnPh320). The
second AB system [δ(P3) ) 68.7 and δ(P4) ) 57.5 ppm]
shows a distinctly lower J PFeF coupling of 13 Hz, which
is assigned to the cis arrangement of the phosphane
ligands in 5b. The same value was found in (CO)2-
(dppe)Fe[Si(OEt)3]SnMe3.20 This assignment is con-
firmed by the analysis of the 2J SnFeP and 3J SnCCP coupling
constants.
The original cis arrangement of Sn and the phenyl
group is retained in 5b. Formation of 5a from 3a
requires a rearrangement, which is possible in the five-
coordinate intermediate formed by CO abstraction from
3a . There is no thermal isomerization up to 85 °C once
5a ,b are formed.
While the iron center in 5 was unreactive toward a
second intramolecular oxidative addition, a Sn-Ph
group of the dangling SnPh3 group is readily added to
the more reactive (Ph3P)2Pt fragment. When a toluene
solution of 5 was reacted with (Ph3P)2Pt(C2H4) at room
temperature, the AB systems of 5 in the 1H NMR
spectrum slowly decreased in intensity, while two new
AB systems grew in. They were assigned to the two
isomers of 6. After 4 days, the signals of 5 had
disappeared. Analysis of the reaction mixture was
complicated by the formation of the platinum complex
7 (eq 4), which was previously prepared by reaction of
(Ph3P)2Pt(C2H4) with Ph2PCH2CH2SnPh3.10
When Pd(PPh3)4 was reacted with 5 at room temper-
ature, the phosphane transfer reaction prevailed, and
only the known complex Pd(PPh2CH2CH2SnPh2)2 was
obtained, which was previously prepared by reaction of
Pd(PPh3)4 with Ph2PCH2CH2SnPh3.10
Attempts to separate the products from the reaction
of 5 with (Ph3P)2Pt(C2H4) by column chromatography
or by crystallization failed. However, the identity and
constitution of 6 was unequivocally established by 31P
NMR and 31P/31P COSY 45 measurements. In the 31P
NMR spectrum, there are four groups of signals for 6a
and 6b each. The chemical shifts and the coupling of
the phosphorus atoms coordinated to the iron center are
very similar to those of 5. However, there is an
additional splitting of the signals of the nuclei P2 and
P4 by coupling with the platinum-bonded phosphorus
atoms P5 and P7, respectively. The COSY experiment
proved that the additional splitting is indeed due to the
unusual J PCCSnPtP coupling. There is a chemical shift
5
difference of 0.2 and 1.1 ppm between the corresponding
phosphorus atoms at platinum in 6a ,b. This shows that
the different geometry at the iron center is transmitted
to the platinum center. The 31P chemical shifts and the
2
1
coupling constants J PPtP,
2SnPtP, and J PtP of P5-P8
allow an unequivocal assignment of the geometry at the
platinum center. The magnitude of 2J PPtP is typical for
a cis-(Ph3P)2Pt arrangement. The nuclei P5 and P7 are
split to a doublet of doublets by coupling with P2 and
2
P4. The J SnPtP coupling constants of P5 and P7 (1753
Hz) are more than 10 times larger than those of P6 and
P8 (133/171 Hz). Therefore, P5 and P7 are trans to Sn.
Similar coupling constants were found for cis-(Ph3P)2-
Pt(Ph)SnPh3 and cis-(Ph3P)(Ph)PtPPh2CH2CH2SnPh2.10,21
The observed couplings are schematically summarized
in Scheme 1 for 6a .
Analogous to the oxidative addition of the dangling
SnPh3 group in 5 to a platinum center, a binuclear
complex (8) was also obtained by the reaction of 4b with
(Ph3P)2Pt(C2H4) (eq 5). The known complex 7 was again
formed as a byproduct. There was no formation of a
Fe-Pt bond by elimination of benzene or PhSi(OMe)3
from 8. Interestingly, the oxidative addition of the Sn-
Ph bond to the platinum center is preferred to that of
the Fe-H bond. By comparison, reaction of (CO)3[Si-
(OMe)3]Fe(H)PPh2CH2PPh2 with (Ph3P)2Pt(C2H4) re-
sulted in the formation of (CO)3[Si(OMe)3]Fe(µ-dppm)-
Pt(H)PPh3.23
The coordination geometry at the iron center was
changed from meridional in 4b to facial in 8. This
phenomenon was previously observed when binuclear
complexes with the (CO)3(R′3P)FeSiR3 fragment were
prepared via the anionic complexes [(CO)3(R′3P)-
FeSiR3]-.19 The complex 8 was only spectroscopically
(21) Carr, S.; Colton, R.; Dakternieks, D. J . Organomet. Chem. 1983,
249, 327.
(22) Schubert, U.; Gilges, H. Organometallics 1996, 15, 2373.
(23) Braunstein, P.; Knorr, M.; Tiripicchio, A.; Tiripicchio Camellini,
M. Angew. Chem. 1989, 101, 1414; Angew. Chem., Int. Ed. Engl. 1989,
28, 1361.
(20) Knorr, M.; Piana, H.; Gilbert, S.; Schubert, U. J . Organomet.
Chem. 1990, 388, 327.

Transition Metal Stannyl Complexes
Organometallics, Vol. 15, No. 22, 1996 4711
Analyzer 990; 1H NMR spectra, Bruker AMX 400 (400.1 MHz);
13C NMR spectra, Bruker AC 200 (50.3 MHz) or Bruker AMX
400 (100.6 MHz); 31P NMR and 119Sn NMR spectra, J eol FX
90Q (36.3 MHz/33.4 MHz) or Bruker AMX 400 (161.9 MHz/
149.2 MHz). If not otherwise stated, only the coupling
constants to 119Sn are given.
Sch em e 1
P r ep a r a tion of (CO)4F eP P h 2CH2CH2Sn P h 3 (1a ) a n d
(CO)3F e(P P h 2CH2CH2Sn P h 3)2 (2a ). A 1.26 g (2.24 mmol)
amount of Ph2PCH2CH2SnPh3 and 1.63 g (4.47 mmol) of Fe2-
(CO)9 were suspended in 20 mL of toluene. Most of the Fe2-
(CO)9 dissolved within 15 min on heating to 60 °C, while the
color of the solution turned to dark brown and gas evolution
occurred. The solution was stirred at 60 °C for additional 30
min to complete the reaction. After separation of the excess
Fe2(CO)9 and removal of all volatile compounds (including Fe-
(CO)5) in vacuo, a brown oil was obtained, which contained
the complexes 1a , 2a , and (a little) 3a , according to the IR
and 31P NMR spectra. The mixture was chromatographed on
silica (column 50 × 1 cm; solvent, 1:1 petroleum ether/toluene).
The first, light yellow zone contained 1a and 3a , the second,
yellow zone only 1a , and the third, orange zone 2a . After
removal of the solvents from the second and the third fraction,
the complexes 1a and 2a are obtained as yellow (1a ) or beige
(2a ) powders on recrystallization at -25 °C from 5 mL of
petroleum ether (1a ) or 10 mL of toluene/petroleum ether (1:
4) (2a ).
characterized because of its thermal instability. How-
ever, the spectroscopic data are fully consistent with the
proposed constitution and the geometry at the two metal
centers.
1a . Yield: 0.85 g (26%). Mp: 74 °C. IR (toluene, cm-1):
ν(CO) ) 2043 (s), 1971 (m) 1938 (vs). 1H NMR (d6-acetone):
δ 7.61-7.35 (m, 25 H, Ph), 2.92 (m, 2 H, PCH2), 1.72 (m, 2 H,
Con clu sion s
Iron carbonyl fragments are inert toward the oxida-
tive addition of nonactivated Sn-C bonds. However,
chelate assistance promotes the addition of such bonds,
and the chelated complexes 3 are readily formed from
1 by intramolecular oxidative addition of the Sn-Ph or
Sn-Me groups of the Ph2P(CH2)nSnR2R′ ligands. Sn-
Ph bonds are more readily added than Sn-Me bonds,
and the formation of five- or six-membered metallacycles
is more favorable than that of four-membered rings, as
expected. The vacant coordination site at the iron atom
necessary for the oxidative addition can be created by
photochemical CO abstraction from the tetracarbonyl
complexes 1. Surprisingly, oxidative addition of the
Sn-Ph bond is also initiated by thermal elimination of
HSiMePh2 from 4a . The oxidative addition of Si-H
bonds is much more favored than that of nonactivated
Sn-C bonds, if the steric and electronic situation at the
tin or silicon atom is comparable. The formation of 3a
from 4a shows that chelate assistance promotes the
(intramolecular) oxidative addition of the Sn-C bond
to a point where it can compete with the readdition of
HSiMePh2. The observation that intramolecular oxida-
tive addition is possible starting from the SiMePh2
derivative 4a but not from the Si(OMe)3 derivative 4b,
in which reductive elimination of the silane is less facile,
gives another qualitative estimate on the magnitude of
the chelate effect. In an earlier work we have shown
for the oxidative addition of Si-H bonds (to tungsten
carbonyl complexes) that stabilization of the oxidative
addition product by chelatation is slightly larger than
by the electronic effects caused by either substituting a
CO ligand for PR3 or by replacing SiR3 (R ) alkyl, aryl)
for SiCl3 in nonchelated complexes.22
SnCH2). 31P{1H} NMR (36.2 MHz, C6D6): δ 72.2 (s, 3J SnCCP
)
253 Hz). Anal. Calc for C36H29FeO4PSn: C, 59.14; H, 4.00.
Found: C, 59.21; H, 4.10.
2a . Yield: 1.17 g (21%). Mp: 114 °C. IR (toluene, cm-1):
ν(CO) ) 1940 (w), 1882 (s) 1876 (s). 1H NMR (C6D6): δ 7.75-
6.90 (m, 25 H, Ph), 3.15 (m, 4 H, PCH2), 2.10 (m, 4 H, SnCH2).
2
31P{1H} NMR (36.2 MHz, C6D6): δ 80.5 (s, A2 portion), J PFeP
) 31 Hz from the ABX portion. Anal. Calc for C67H58FeO3P2-
Sn2: C, 63.55; H, 4.62. Found: C, 63.31; H, 4.80.
P r ep a r a t ion of (CO)3(P h )F eP P h 2CH 2CH 2Sn P h 2 (3a ).
(a ) F r om 1a . A 0.64 g (0.88 mmol) amount of 1a was dissolved
in 20 mL of toluene and irradiated for 2 h at -20 °C, during
which gas was evolved and the yellow color of the solution
intensified. After filtration and removal of the solvent, 3a was
crystallized at -25 °C from 5 mL of toluene/petroleum ether
(1:2) and then washed three times with 2 mL of petroleum
ether each. Yield: 0.43 g (79% from 1a ).
(b) Dir ect Syn th esis fr om F e2(CO)9. A 727 mg (2.00
mmol) amount of Fe2(CO)9 and 563 mg (1.00 mmol) of Ph2-
PCH2CH2SnPh3 were reacted as described above. After re-
moval of excess Fe2(CO)9 by filtration, the brown solution was
diluted with toluene to 100 mL and then irradiated for 20 h
at -10 °C. The IR bands of 2a disappeared within a few hours
during the photolysis. The reaction was finished when the
mono(phosphane) complex 1a was no longer observed in the
IR spectrum. Isolation of 3a was the same as for method a.
Yield: 0.49 g (71% from Ph2PCH2CH2SnPh3) of yellow powder.
Mp: 178 °C. IR (toluene, cm-1): ν(CO) ) 2028 (w), 1983 (m,
sh), 1964 (vs). 1H NMR (d6-acetone): δ 7.59-7.04 (m, 20 H,
PPh and SnPh), 6.81-6.79 (m, 5 H, FePh), 2.75 (m, 2 H, PCH2),
1.59 (m, 2 H, SnCH2). 31P{1H} NMR (161.9 MHz, C6D6): δ
78.7 (s, J SnP ) 75 Hz). 13C{1H} NMR (100.6 MHz, C6D6): δ
2
2
213.1 (d, COax, J PFeC ) 14.5 Hz), 212.7 (d, COeq, J PFeC ) 11.8
1
Hz), 146.3-123.9 (C6H5), 33.0 (d, PCH2, J PC ) 32.4 Hz), 10.1
(d, SnCH2, J PCC ) 19.4 Hz). 119Sn NMR (33.4 MHz, C6D6): δ
2
137.5 (d, J SnP ) 75 Hz). Anal. Calc for C35H29FeO3PSn: C,
59.79; H, 4.16. Found: C, 59.52; H, 4.45.
Exp er im en ta l Section
All operations were performed in an atmosphere of dry and
oxygen-free nitrogen, using dried and argon-saturated sol-
vents. For UV irradiation, a water-cooled mercury high-
pressure lamp TQ 150 (180 W, Heraeus) and Pyrex glassware
were used. Instrumentation: Melting points, DuPont Thermal
(c) F r om (CO)4F e(H)SiMeP h 2. To a solution of 549 mg
(1.50 mmol) of (CO)4Fe(H)(SiMePh2) in 20 mL of toluene was
added 845 mg (1.50 mmol) of Ph2PCH2CH2SnPh3. The solution
was stirred for 18 h at room temperature and then at 70 °C
for 4 h. The reaction was monitored by IR and 31P NMR

4712 Organometallics, Vol. 15, No. 22, 1996
Schubert and Grubert
2
spectroscopy. There was a violent formation of gas, and the
solution turned brown. After the gas evolution ceased, the IR
spectrum only showed the CO bands of 3a . The solution was
filtered, the solvent removed in vacuo, and 3a crystallized from
toluene/petroleum ether (1:1) at -25 °C. The crystals were
washed several times with 10 mL of petroleum ether each,
until the solution was colorless. Additional fractions of 3a
were obtained from the combined washing solutions. Yield:
875 mg (83%).
H, PCH2), 0.70 (m, 2 H, SnCH2), 0.52 (s, 3H, SnCH3, J SnCH
)
37 Hz), -0.45 (d, 3 H, FeCH3, J PFeCH ) 9 Hz). 31P{1H} NMR
(161.9 MHz, C6D6): δ 83.2 (J SnP ) 76 Hz). A byproduct with
δ 88.2 (J SnP ) 222 Hz) was additionally observed.
P r epar ation of (CO)3(H)(P h 2MeSi)FeP P h 2CH2CH2Sn P h 3
(4a ). A solution of (CO)4Fe(H)(SiMePh2) in d8-toluene was
transferred to a NMR tube. When a 1.5-fold excess of Ph2-
PCH2CH2SnPh3 was added at -50 °C, violent gas evolution
occurred. The sample was held at -50 to -30 °C, until the
reaction was finished. 1H NMR (d8-toluene, -40 °C): δ 7.9-
6.8 (m, 35 H, Ph), 2.71 (m, 2 H, PCH2), 1.55 (m, 2 H, SnCH2),
3
P r ep a r a tion of (CO)3(P h )F eP P h 2CH2CH2Sn MeP h (3b).
A solution of 0.78 g (1.49 mmol) of Ph2PCH2CH2SnMePh2 in
10 mL of toluene was added to a suspension of 1.09 g (3.00
mmol) of Fe2(CO)9 in 20 mL of toluene. The reaction mixture
was warmed to 40 °C until most of the Fe2(CO)9 had dissolved
by reaction, during which the color of the solution turned
brown and gas was evolved. After cooling, excess Fe2(CO)9 was
filtrated off. The IR and 31P NMR spectra showed the presence
of the compounds 1-3b. After removal of all volatiles in vacuo,
the obtained brown, viscous oil was submitted to column
chromatography at -5 °C (column 40 × 0.5 cm, silica gel). Four
fractions were obtained. The first three were eluted with
petroleum ether/toluene (1:1), and the fourth was eluted with
toluene. Only the bis(phosphane) complex 2b (IR (toluene
cm-1): ν(CO) ) 1939 (m), 1885 (s), 1875 (s, sh)) was separated
(4th zone) by this procedure.
2
1.24 (s, 3 H, SiCH3), -9.04 (d, 1 H, FeH, J PFeH ) 27.7 Hz).
31P{1H} NMR (161.9 MHz, d8-toluene, -40 °C): δ 59.1 (3J SnCCP
) 252 Hz).
P r ep a r a t ion of (CO)3(H )[(MeO)3Si]F eP P h 2CH 2CH 2-
Sn P h 3 (4b). The solution of 845 mg (1.50 mmol) of Ph2PCH2-
CH2SnPh3 in 35 mL of toluene was added to a freshly prepared
solution of 1.50 mmol of (CO)4Fe(H)Si(OMe)3 in 35 mL of
petroleum ether. The solution was stirred for 6 h at -30 °C
until gas formation was finished. The yellow solution was
quickly filtered, and the solvents were removed in vacuo. The
yellow raw product was washed several times at 0 °C with 20
mL of petroleum ether each, until the solution stayed colorless.
Yield: 0.60 g (48%). Mp: 44 °C (dec), light-yellow powder. IR
(toluene, cm-1): ν(CO) ) 2043 (w), 1985 (s, sh) 1974 (vs). 1H
NMR (C6D6): δ 7.9-6.9 (m, 25 H, Ph), 3.75 (s, 9 H, OCH3),
2.80 (m, 2 H, PCH2), 1.61 (m, 2 H, SnCH2), -9.19 (d, 1 H, FeH,
2J PFeH ) 26.0 Hz). 31P{1H} NMR (161.9 MHz, C6D6): δ 57.5
(3J SnCCP ) 239 Hz). 13C{1H} NMR (50.3 MHz, C6D6): δ 210.8
(d, CO, 2J PFeC ) 12.1 Hz), 137.7-127.5 (C6H5), 50.6 (s, OCH3),
Zones 1-3 were combined, dissolved in 100 mL of toluene,
and irradiated with UV light at -20 °C for 5 h. After
separation of the insoluble parts and the removal of the solvent
in vacuo, a brown oil was obtained, which was dissolved in
0.5 mL of toluene. Upon addition of 10 mL of pentane the
ochre complex 3b was precipitated, which was washed three
times with 5 mL of pentane each. Yield: 392 mg (41%). Mp:
44 °C (dec). IR (toluene, cm-1): ν(CO) ) 2023 (s), 1978 (s, sh)
1956 (vs). 1H NMR (C6D6): δ 7.83-6.93 (m, 20 H, Ph), 2.25
(m, 2 H, PCH2), 1.26 (m, 2 H, SnCH2), 0.73 (s, 3 H, SnCH3,
2J SnCH ) 46 Hz). 31P{1H} NMR (161.9 MHz, C6D6): δ 79.3 (J SnP
2
30.5 (d, PCH2, J PC ) 20.0 Hz), 3.5 (d, SnCH2, J PCC ) 3.6 Hz).
Anal. Calc for C38H39FeO6PSiSn: C, 55.30; H, 4.76. Found:
C, 54.92; H, 4.72.
P r ep a r a tion of (CO)2(P h )F e(P P h 2CH2CH2Sn P h 2)P P h 2-
CH2CH2Sn P h 3 (5). (a ) F r om 2. A solution of 0.99 g (0.78
mmol) of 2 in 20 mL of toluene was irradiated for 7 h at -20
°C. The progress of the reaction was monitored by IR and 31P
NMR spectroscopy. After irradiation for 2 h, the starting
compound had completely disappeared in the IR spectrum.
New CO bands were observed at 2030 (w), 1980 (w), 1964 (m),
and 1906 cm-1, and in the 31P NMR spectrum the signals of 5
and resonances at 78.7, 30.3, and -9.49 ppm were observed.
After an additional 5 h of irradiation, the IR spectrum of the
yellow solution showed only one CO band at 1905 cm-1. In
the 31P NMR spectrum, the four doublets of 5a ,b and ad-
ditional weak signals at 30.3-9.49 ppm were observed. After
removal of the solvent and crystallization from 1:1 petroleum
ether/toluene at -25 °C, complex 5 was obtained as a yellow
powder. Yield: 0.45 g (46% from 2).
) 69 Hz). 13C{1H} NMR (100.6 MHz, C6D6): δ 213.9 (d, COax
,
2
2J PFeC ) 14 Hz), 213.1 (d, COeq, J PFeC ) 9.8 Hz), 145.8-125.6
1
2
(Ph), 33.2 (d, PCH2, J PC ) 32.3 Hz), 9.8 (d, SnCH2, J PCC
)
19.7 Hz), -6.1 (s, SnCH3, J SnC ) 329 Hz). 119Sn NMR (33.4
MHz, C6D6): δ 169.0 (d, J SnP ) 70 Hz). Anal. Calc for
1
C
30H27FeO3PSn: C, 56.16; H, 4.25. Found: C, 55.09; H, 4.03.
P r ep a r a tion of (CO)3F e(P P h 2CH2CH2Sn Me3)2 (2c) a n d
(CO)3(Me)F eP P h 2CH2CH2Sn Me2 (3c). The suspension of
2.00 g (5.52 mmol) of Fe2(CO)9 and 1.04 g (2.76 mmol) of Ph2-
PCH2CH2SnMe3 in 30 mL of toluene was stirred for 2 h at
room temperature, during which a violent formation of gas was
observed. After filtration of the excess Fe2(CO)9 and removal
of all volatile components in vacuo, an orange colored oil was
obtained. The IR and 31P NMR spectra showed the presence
of the compounds 1-3c, the compound 3c only in traces. The
mixture was submitted to column chromatography (column 25
× 1 cm, petroleum ether, silica gel). The first yellow zone
contained a mixture of 1c and 3c. The second, orange colored
fraction contained 2c. The compound 2c was obtained as a
yellow powder after removal of the solvent from the second
zone and crystallization from 5 mL of petroleum ether at -25
°C. Yield: 0.44 g (18%). Mp: 138 °C. IR (toluene, cm-1): ν-
(CO) ) 2043 (w), 1884 (s), 1872 (s, sh). 1H NMR (C6D6): δ
7.42-6.97 (m, 20 H, Ph), 2.88 (m, 4 H, PCH2), 1.29 (m, 4 H,
SnCH2), -0.02 (s, 18H, SnCH3, 2J SnCH ) 53 Hz). 31P{1H} NMR
(161.9 MHz, C6D6): δ 80.6 (s with ABX subspectra). Anal. Calc
for C37H46FeO3P2Sn2: C, 49.71; H, 5.19. Found: C, 50.03; H,
5.06.
(b) Dir ect Syn th esis fr om F e2(CO)9. A 364 mg (1.00
mmol) amount of Fe2(CO)9 and 2.25 g (4.00 mmol) of Ph2PCH2-
CH2SnPh3 were reacted in 20 mL of toluene at 60 °C as
described above. After filtration and dilution to 100 mL, the
solution was irradiated for 19 h at -10 °C. After 7 h the CO
bands of 1a and 2a had disappeared, and the band of 5 at 1906
cm-1 was already observed besides that of 3a . The reaction
was finished, when the CO bands of 3a no longer decreased
in intensity. After the separation of a small amount of an
unsoluble compound, the solvent was removed in vacuo from
the brown solution. The product precipitated when the
obtained brown oil was stirred for 1 h with 20 mL of toluene/
petroleum ether (1:1). The yellow solid was washed three
times with 10 mL of petroleum ether each. From the combined
solutions additional fractions of the product were obtained by
crystallization of the concentrated solutions at -25 °C.
Yield: 0.97 g (78%). Mp: 115 °C (dec). IR (toluene, cm-1):
ν(CO) ) 1906 (s). 1H NMR (C6D6, numbering of the P atoms
shown in eq 2): δ 7.73-6.72 (m, 50 H, Ph), 2.70 (m, 2 H,
P1CH2), 2.58 (m, 2 H, P3CH2), 2.37 (m, 4 H, P4/2CH2), 1.40 (m,
2 H, SnCH2), 1.34 (m, 2 H, SnCH2), 1.17 (m, 4 H, SnCH2). 31P-
{1H} NMR (161.9 MHz, C6D6): Isomer 5a , δ 74.8 (P1, d,
The first zone of the chromatography was dissolved in 70
mL of toluene and irradiated at -20 °C for 45 min. After
filtration and removal of the solvent a yellow oil was obtained.
The product was recrystallized from 2 mL of petroleum ether
at -78 °C. The yellow crystals of 3c already contained some
brown decomposition products. IR (toluene, cm-1): ν(CO) )
2013 (w), 1964 (s, sh), 1944 (s). 1H NMR (C6D6): δ 1.67 (m, 2

Transition Metal Stannyl Complexes
Organometallics, Vol. 15, No. 22, 1996 4713
2
2J PFeP
) 57 Hz, J
) 52 Hz), 62.7 (P2, d, J SncisFeP
)
)
4-times washed with 20 mL of petroleum ether each. Yield:
117/119
SnP
trans
114 Hz; 3J SnCCP ) 200 Hz); isomer 5b, δ 68.7 (P3, d, J PFeP
2
3.8 g (62%). Mp: 85 °C, colorless solid. 1H NMR (CDCl3): δ
cis
13 Hz, J SnP ) 57 Hz), 57.5 (P4, d, J SnP ) 169 Hz). Anal. Calc
for C66H58FeO2P2Sn2: C, 64.01; H, 4.72. Found: C, 65.88; H,
5.02.
2
2
7.25 (m, 25 H, Ph), 2.01 (d, 2 H, CH2, J PCH ) 2 Hz, J SnCH
)
61 Hz). 13C NMR (CDCl3): δ 134.6 (m, Ph), 8.7 (d, CH2, J PC
1
) 34 Hz). 31P{1H} NMR (161.9 MHz, d6-acetone): δ -19.9
(2J SnCP ) 109 Hz). 119Sn NMR (33.4 MHz, d6-acetone):
δ
(c) By P h otoch em ica l Rea ction of 3a w ith P h 2P CH2-
CH2Sn P h 3. A 608 mg (0.87 mmol) amount of 3a was dissolved
in 50 mL of toluene and cooled to -10 °C. A solution of 487
mg (0.87 mmol) of Ph2PCH2CH2SnPh3 in 20 mL of toluene was
then added. The solution was irradiated at -10 °C, during
which it turned intensively yellow, and a gas was formed. The
reaction was monitored by IR spectroscopy. After 11 h the
CO bands of 3a had nearly disappeared. Spectroscopic analy-
sis (1H NMR, 31P{1H} NMR) of the product after filtration and
removal of the solvent showed that 5a ,b were formed in a 1:1
ratio.
-109.2 (d). Anal. Calc for C31H27PSn: C, 67.79; H, 4.95; Sn,
21.6. Found: C, 67.81; H, 4.96; Sn, 20.8.
P r ep a r a tion of (CO)4F eP P h 2(CH2)nSn P h 3 (1d , n ) 1; 1e,
n ) 3). The preparation was performed analogous to that of
1a , starting from 2.00 mmol of Ph2P(CH2)nSnPh3. In the
reaction of Ph2PCH2SnPh3, only the mono(phosphane) complex
1d was formed, while in the reaction of Ph2P(CH2)3SnPh3 the
bis(phosphane) complex 2e (IR ν(CO) ) 1885 cm-1 31P NMR
;
δ 73.0) and the oxidative addition product 3e were obtained
as minor byproducts. These compounds were separated by
column chromatography as described for 1a . The compounds
1d ,e were obtained as yellow solids by recrystallization from
toluene/petroleum ether (5:1) at -25 °C.
P r ep a r a tion of (CO)2(P h )F e(P P h 2CH2CH2Sn P h 2)P P h 2-
CH2CH2Sn P h 2P t(P h )(P P h 3)2 (6). A solution of 169 mg (0.20
mmol) of (Ph3P)2Pt(C2H4) was added in several portions at
room temperature during 30 min to a solution of 204 mg (0.17
mmol) of 5 in 5 mL of toluene. While the color changed from
yellow to red, an immediate formation of gas was observed.
The solution was stirred in the dark for 4 days. After 4 h, 2
days, and 4 days the solution was analyzed by 31P NMR
spectroscopy. Two microspatulas of (Ph3P)2Pt(C2H4) were
added after 4 h and 2 d, because unreacted 5 was observed
but no (Ph3P)2Pt(C2H4). Complex 5 was completely consumed
after 4 days. To remove excess (Ph3P)2Pt(C2H4) (by thermal
decomposition), the solution was heated to 40 °C for 2 h.
Attempts to separate the product complexes by crystallization
from toluene/petroleum ether or toluene/methylene chloride
mixtures or by column chromatography failed.
1d . Yield: 889 mg (62%). Mp: 69 °C (dec). IR (toluene,
cm-1): ν(CO) ) 2043 (w), 1972 (m) 1938 (vs). 1H NMR
2
(C6D6): δ 7.70-7.05 (m, 25 H, Ph), 2.63 (d, 2 H, CH2, J PCH
)
11 Hz, J SnCH ) 64 Hz). 31P{1H} NMR (161.9 MHz, C6D6): δ
64.6 (2J SnCP ) 70 Hz). 119Sn NMR (33.4 MHz, C6D6): δ -112.6
(d). Anal. Calc for C35H27FeO4PSn: C, 58.62; H, 3.80.
Found: C, 58.44; H, 3.71.
2
1e. Yield: 628 mg (43%). Mp: 76 °C (dec). IR (toluene,
cm-1): ν(CO) ) 2040 (s), 1974 (m) 1937 (vs). 1H NMR (C6D6):
δ 7.51-7.12 (m, 25 H, Ph), 2.40 (m, 2 H, PCH2), 2.00 (m, 2 H,
CH2CH2CH2), 1.26 (m, 2 H, SnCH2). 31P{1H} NMR (161.9
MHz, C6D6): δ 64.0 (4J SnCCCP ) 14 Hz). 119Sn NMR (33.4 MHz,
C6D6): δ -104.0 (d). Anal. Calc for C37H31FeO4PSn: C, 59.65;
H, 4.19. Found: C, 59.12; H, 3.98.
6. IR (toluene, cm-1): ν(CO) ) 1904 (s). 31P{1H} NMR
(161.9 MHz, d8-toluene, numbering of the phosphorus atoms
2
shown in eq 4): Isomer 6a , δ 74.6 (P1, d, J PFeP
) 55 Hz,
P r ep a r a tion of (CO)3(P h )F eP P h 2(CH2)nSn P h 2 (3d , n )
1; 3e, n ) 3). The preparation was performed analogous to
that of 3a starting from 500 mg (0.69 mmol) of 1d and 318
mg (0.43 mmol) of 1e (irradiation in toluene for 7 h and 3 h at
-20 °C).
When the irradiation of 1d was monitored by 31P NMR
spectroscopy, the dominating signal was that of 3d . However,
several byproducts were formed, with 31P NMR signals be-
tween 73 and 10 ppm. The complete separation of the side
products was possible neither by crystallization nor by column
chromatography. The column chromatography (column 30 ×
0.5 cm, 1:1 toluene/petroleum ether) at 0 °C resulted in five
fractions. The second, yellow fraction only contained 1d and
3d . Crystallization at -25 °C from toluene/petroleum ether
(5:1) only resulted in an enrichment of 3d but not in a complete
separation from 1d .
trans
2
5
J SnP ) 54 Hz), 61.8 (P2, dd, J PFeP
) 55 Hz, J PCCSnPtP ) 10
5
trans
Hz, J SnP ) 171 Hz), 26.8 (P5, dd, 2J PPtP ) 14 Hz, 2J SntransPtP
)
cis
1753 Hz, 1J PtP ) 2245 Hz), 23.1 (P6, d, 2J SncisPtP ) 171 Hz, 1J PtP
) 2060 Hz); isomer 6b, δ 69.6 (P3, d, J PFeP ) 13 Hz, J SnP
)
2
cis
57 Hz), 58.2 (P4, dd, J PCCSnPtP ) 7 Hz, J SnP ) 231 Hz), 26.6
5
7
(P7, dd, J PPtP ) 14 Hz, J SntransPtP ) 1753 Hz, J PtP ) 2233
2
2
1
cis
Hz), 22.0 (P8, d, J SncisPtP ) 171 Hz, J PtP ) 2046 Hz). 119Sn
2
1
2
1
NMR (149.2 MHz, C6D6): Isomer 6a , δ 112.9 (dd, J SnFeP
)
53 Hz, 2J SnFeP ) 107 Hz); isomer 6b, δ 131.4 (dd, J SnFeP ) 60
2
2
3
2
4
Hz, J SnFeP ) 168 Hz).
P r ep a r a tion of (CO)3(H)[(MeO)3Si]F e(P P h 2CH2CH2-
Sn P h 2)P t(P h )(P P h 3)2 (8). The solution of 316 mg (0.38
mmol) of (Ph3P)2Pt(C2H4) in 10 mL of toluene was added to
the solution of 310 mg (0.38 mmol) of 4b in 10 mL of toluene
at 0 °C. The solution was stirred for 1 h, during which a weak
formation of gas was observed. The evolved CO was occasion-
ally removed in vacuo. After filtration and removal of the
solvent in vacuo, the yellow solid was washed three times with
5-10 mL of pentane each. The spectroscopic data showed that
7 was additionally formed. Complex 8 was only spectroscopi-
cally characterized. IR (toluene, cm-1): ν(CO) ) 2035 (w),
1970 (s) 1915 (s). 1H NMR (C6D6): δ 7.6-6.5 (m, 40 H, Ph),
3.80 (s, 9 H, SiOCH3), 2.39 (m, 2 H, PCH2), 1.20 (m, 2 H,
SnCH2), -9.45 (d, 1 H, FeH, 2J PFeH ) 25.2 Hz). 31P{1H} NMR
(161.9 MHz, C6D6, numbering of the P atoms shown in eq 5:
Compound 3e was obtained by crystallization from 15 mL
of toluene/petroleum ether (10:1) at -25 °C as a beige solid.
3d . IR (toluene, cm-1): ν(CO) ) 2025 (w), 1985 (m, sh), 1965
(vs). 1H NMR (C6D6): δ 7.74-6.73 (m, 25 H, Ph), 2.68 (d, 2
H, PCH2, 2J PCH ) 12 Hz, 2J SnCH ) 45 Hz). 31P{1H} NMR (161.9
MHz, C6D6): δ 7.1 (J SnP ) 9 Hz).
3e. Yield: 207 mg (67%). Mp: 66 °C (dec). IR (toluene,
cm-1): ν(CO) ) 2023 (m), 1979 (s, sh), 1955 (vs). 1H NMR
(C6D6): δ 7.58-6.81 (m, 25 H, Ph), 1.76 (m, 4 H, PCH2CH2),
1.19 (m, 2 H, SnCH2). 31P{1H} NMR (161.9 MHz, C6D6): δ
42.9 (s, J SnP ) 134 Hz). 119Sn NMR (33.4 MHz, C6D6): δ 12.9
(d, J SnP ) 137 Hz). Anal. Calc for C36H31FeO3PSn: C, 60.29;
H, 4.36. Found: C, 58.68; H, 4.23.
δ 56.0 (P1, d, J SnCCP ) 68 Hz, J PCCSnPtP ) 12 Hz), 26.5 (P2, t,
3
5
2
2
2
1
J PPtP /5J PCCSnPtP ) 13 Hz, J PPtSn
) 1793 Hz, J PtP ) 2311
1
cis
trans
2
Hz), 21.5 (P3, d, J PPtP ) 14 Hz, J SncisPtP ) 171 Hz, J PtP
)
2
1
cis
2050 Hz).
P r ep a r a tion of P h 2P CH2Sn P h 3. A solution of 2.29 (11.1
mmol) of LiCH2PPh2 in 40 mL of THF was added dropwise to
a solution of 4.50 g (11.7 mmol) of Ph3SnCl in 40 mL of THF
at -50 °C. The mixture was then warmed to room tempera-
ture and stirred for 24 h. The yellow oil obtained by removal
of the solvent in vacuo was dissolved in 50 mL of toluene and
filtered. After removal of the solvent in vacuo, the solid was
Ack n ow led gm en t. This work was supported by the
Deutsche Forschungsgemeinschaft (Bonn) and the Fonds
zur Fo¨rderung der wissenschaftlichen Forschung
(Vienna).
OM960424V