Synthesis and molecular structures of perfluoro-n-alkyl complexes of platinum(II) and platinum(IV) containing tetramethylethylenediamine (TMEDA) or 1,2-bis(diphenylphosphino)ethane (DPPE) ligands

Article abstract of DOI:10.1021/om010424h

Reaction of (TMEDA)Pt(CH₃)₂ with n-perfluoropropyl iodide in hexanes results in an apparent cis addition of the perfluoroalkyl iodide to give the six-coordinate Pt(IV) complex (TMEDA)Pt(n-C₃F₇)(CH₃)

Full text of DOI:10.1021/om010424h

3800
Organometallics 2001, 20, 3800-3810
Syn th esis a n d Molecu la r Str u ctu r es of P er flu or o-n -a lk yl
Com p lexes of P la tin u m (II) a n d P la tin u m (IV) Con ta in in g
Tetr a m eth yleth ylen ed ia m in e (TMEDA) or
1,2-Bis(d ip h en ylp h osp h in o)eth a n e (DP P E) Liga n d s
Russell P. Hughes,*,† J oel T. Sweetser,† Mark D. Tawa,† Alex Williamson,†
Christopher D. Incarvito,‡ Brian Rhatigan,‡ Arnold L. Rheingold,‡ and
Gene Rossi‡
Departments of Chemistry, 6128 Burke Laboratory, Dartmouth College,
Hanover, New Hampshire 03755, and University of Delaware, Newark, Delaware 19716
Received May 21, 2001
Reaction of (TMEDA)Pt(CH3)2 with n-perfluoropropyl iodide in hexanes results in an
apparent cis addition of the perfluoroalkyl iodide to give the six-coordinate Pt(IV) complex
(TMEDA)Pt(n-C3F7)(CH3)2I (6a ). Complex 6a slowly and reversibly reductively eliminates
CH3I in solution to afford an equilibrium with the Pt(II) complex (TMEDA)Pt(n-C3F7)(CH3)
(9a ). Addition of triethylamine drives the equilibrium toward 9a . Identical reactions of
perfluoroethyl iodide are observed to afford 6b and 9b. Reaction of 6a with AgBF4 generates
the cationic Pt(IV) complex [(TMEDA)Pt(n-C3F7)(CH3)2(OH2)]BF4 (11), which reacts with
NaCl to form (TMEDA)Pt(n-C3F7)(CH3)2Cl (12); both reactions retain the cis stereochemistry
of the starting material 6a . Reaction of 9a with CF3SO3H in moist solvents generates the
cationic Pt(II) complex [(TMEDA)Pt(n-C3F7)(OH2)]O3SCF3 (17), which reacts with iodide to
afford the neutral iodide complex (TMEDA)Pt(n-C3F7)I (14). Reaction of complex 9a with I2
in hexanes results in trans addition of I2 to generate (TMEDA)Pt(C3F7)(CH3)I2 (13), which
is converted to (TMEDA)Pt(n-C3F7)I (7) by treatment with AgBF4 followed by NaI. Complex
14 reacts with NaBH4 to produce (TMEDA)Pt(n-C3F7)H (18). The TMEDA ligand can be
displaced from 9a by DPPE to give (DPPE)Pt(n-C3F7)(CH3) (19), which reacts with CF3-
SO3H to give the triflate complex (DPPE)Pt(n-C3F7)O3SCF3 (20), in equilibrium with a water
complex, [(DPPE)Pt(n-C3F7)(OH2)]O3SCF3 (21). Reaction of 20 with iodide, or 19 with I2,
gives (DPPE)Pt(n-C3F7)I (22), which can be converted to the hydrido complex (DPPE)Pt(n-
C3F7)H (23) with NaBH4. The X-ray crystal structures of complexes 6a , 9a , 9b, 10, 13, 18,
19, 20, and 23 have been determined, and structural comparisons in terms of ligand cis and
trans influences are discussed.
In tr od u ction
such complexes have also been reported using oxidative
addition methodology, usually involving perfluoroalkyl
iodides,7-12 but we have shown previously that this
route can be problematical for both early and late metals
due to fluoroalkylation at ligand sites, rather than at
the metal center.13-16
There have been many studies of oxidative additions
of alkyl halides to square planar Pt(II) precursors.17-21
In most cases, reactions of primary alkyl iodides and
The oxidative addition reaction of an alkyl halide to
a metal center is among the most useful methods of
forming a new metal-carbon bond.1 As a result of a
recent renaissance of interest in the chemistry of
fluoroalkyl ligands, involving F-migrations to and from
metal centers2,3 and activation of carbon-fluorine bonds
by hydrolysis,4 hydrogenolysis,5 or hydride reagents,6
we have been interested in reevaluating and expanding
some of the previously reported methodology for the
synthesis of late metal-fluoroalkyl complexes. Many
(7) McCleverty, J . A.; Wilkinson, G. J . Chem. Soc. 1964, 4200-4203.
(8) Rosevear, D. T.; Stone, F. G. A. J . Chem. Soc. A 1968, 164-167.
(9) Mukhedkar, A. J .; Green, M.; Stone, F. G. A. J . Chem. Soc. (A)
1969, 3023-3026.
† Dartmouth College.
‡ University of Delaware.
(10) Stone, F. G. A. Endeavour 1966, 25, 33-38.
(1) Collman, J . P.; Hegedus, L. S.; Norton, J . R.; Finke, R. G.
Principles and Applications of Organotransition Metal Chemistry;
University Science Books: Mill Valley, CA, 1987.
(2) Huang, D.; Koren, P. R.; Folting, K.; Davidson, E. R.; Caulton,
K. G. J . Am. Chem. Soc. 2000, 122, 8916-8931.
(3) Huang, D.; Caulton, K. G. J . Am. Chem. Soc. 1997, 119, 3185-
3186.
(4) Hughes, R. P.; Lindner, D. C.; Rheingold, A. L.; Liable-Sands,
L. M. J . Am. Chem. Soc. 1997, 119, 11544-11545.
(5) Hughes, R. P.; Smith, J . M. J . Am. Chem. Soc. 1999, 121, 6084-
6085.
(11) Clark, H. C.; Manzer, L. E. J . Organomet. Chem. 1973, 59, 411-
428.
(12) Appleton, T. G.; Hall, J . R.; Kennard, C. H. L.; Mathieson, M.
T.; Neale, D. W.; Smith, G.; Mak, T. C. W. J . Organomet. Chem. 1993,
453, 299-306.
(13) Hughes, R. P.; Maddock, S. M.; Guzei, I. A.; Liable-Sands, L.
M.; Rheingold, A. L. J . Am. Chem. Soc. 2001, 123, 3279-3288.
(14) Hughes, R. P.; Husebo, T. L.; Holliday, B. J .; Rheingold, A. L.;
Liable-Sands, L. M. J . Organomet. Chem. 1997, 548, 109-112.
(15) Hughes, R. P.; Maddock, S. M.; Rheingold, A. L.; Liable-Sands,
L. M. J . Am. Chem. Soc. 1997, 119, 5988-5989.
(6) Draft, B. M.; Lachicotte, R. J .; J ones, W. D. J . Am. Chem. Soc.
2000, 122, 8559-8560.
(16) Hughes, R. P.; Husebo, T. L.; Rheingold, A. L.; Liable-Sands,
L. M.; Yap, G. P. A. Organometallics 1997, 16, 5-7.
10.1021/om010424h CCC: $20.00 © 2001 American Chemical Society
Publication on Web 07/26/2001

Perfluoro-n-alkyl Complexes of Pt(II) and Pt(IV)
Organometallics, Vol. 20, No. 17, 2001 3801
bromides with dimethyl platinum(II) complexes occur
by a polar SN2 mechanism to give a Pt(IV) complex with
kinetically controlled trans stereochemistry,18 although
cis products have been shown to result from subsequent
isomerization.22 On occasion, cationic five-coordinate
intermediates have been detected spectroscopically.23
Not surprisingly, the five-coordinate intermediate in the
oxidative addition reaction has also been shown to serve
as the key intermediate for reductive elimination of
methyl iodide or ethane from Pt(IV).24-26
While most studies of oxidative addition/reductive
elimination to Pt(II) have involved complexes bearing
monodentate or bidentate phosphorus ligands, com-
pounds with chelating nitrogen ligands have also been
examined.18 cis-Dialkyl and -diarylplatinum(II) com-
plexes with nitrogen-donor ligands usually react with
alkyl halides to give the trans oxidative addition
product,27-30 while the corresponding cis isomer can be
formed either by competitive cis oxidative addition
pathways or by trans oxidative addition with subse-
quent isomerization of the platinum(IV) product to a
thermodynamically more stable cis isomer.18 Dimeth-
ylplatinum(II) complexes containing pyridine,27 2,2′-
bipyridine,31 1,10-phenanthroline,31,32 and tetrameth-
ylethylenediamine (TMEDA) ligands33,34 have been
studied. For example, reaction of (TMEDA)Pt(CH 3)2
(1) with benzyl bromide affords the trans addition
product 2.33
complexes, though none could be isolated in pure form.11
These products are all presumed to result from facile
reductive elimination from a platinum(IV) intermediate.
Recently, we described the reactions of perfluoroalkyl
iodides with (TMEDA)Pd(CH3)2 to give square planar
fluoroalkyl complexes 3 and 4.35 These reactions were
also assumed to proceed via oxidative addition to give
an unobserved Pd(IV) intermediate, followed by reduc-
tive elimination to give the Pd(II) product. Products 3
and 4 exhibited interesting structural parameters and
variable-temperature NMR behavior, and we were
interested in preparing their Pt(II) analogues for com-
parison and to see if we could observe Pt(IV) intermedi-
ates en route to their formation. Accordingly, we have
studied the corresponding reactions of the platinum
analogue 1 with various fluoroalkyl iodides.
Fluoroalkyl complexes of platinum have also been
approached in a similar fashion. For example, (COD)-
Pt(CH3)2 reacts with CF3I to give (COD)Pt(CF3)2 with
[Pt(CH3)3I]4 as a byproduct;11 subsequently the mixed
alkyl compound (COD)Pt(CH3)(CF3) was also identified
as a product,12 and (NBD)Pt(CH3)2 was shown to afford
(NBD)Pt(CH3)(CF3) and (NBD)Pt(CF3)2.12 Reactions
with perfluoroethyl, perfluoropropyl, and perfluoroiso-
propyl iodides apparently formed stable platinum(II)
(17) Ellis, P. R.; Pearson, J . M.; Haynes, A.; Adams, H.; Bailey, N.
A.; Maitlis, P. M. Organometallics 1994, 13, 3215-3226.
(18) Rendina, L. M.; Puddephatt, R. J . Chem. Rev. 1997, 97, 1735-
1754.
(19) J awad, J . K.; Puddephatt, R. J . J . Chem. Soc., Dalton Trans.
1977, 1466-1469.
(20) J awad, J . K.; Puddephatt, R. J . J . Organomet. Chem. 1976, 117,
297-302.
(21) Scott, J . D.; Puddephatt, R. J . Organometallics 1986, 5, 1538-
1544.
(22) Felice, V. D.; Giovannitti, B.; Renzi, A. D.; Tesauro, D.; Penunzi,
A. J . Organomet. Chem. 2000, 593-594, 445-453.
(23) Crespo, M.; Puddephatt, R. J . Organometallics 1987, 6, 2548-
2550.
Resu lts a n d Discu ssion
(24) Brown, M. P.; Puddephatt, R. J .; Upton, C. E. E. J . Chem. Soc.,
Dalton Trans. 1974, 2457-2465.
P er flu or oa lk yl P t(IV) a n d P t(II) Com p lexes w ith
TMEDA Liga n d s. When a suspension of 1 in hexanes
is treated with n-C3F7I, the starting material rapidly
dissolves to form a yellow solution, from which a white
solid slowly precipitates in excellent yield. The 1H NMR
spectrum of the product is consistent with a Pt(IV)
adduct, (TMEDA)Pt(C3F7)(CH3)2I, exhibiting four dis-
tinct NMe resonances and two separate PtMe signals.
The 19F NMR spectrum shows each pair of fluorines in
the CF2 groups to be diastereotopic; the two R-CF2
fluorine resonances are well separated (by 16.5 ppm),
show a large geminal coupling constant, 2J FF ) 257 Hz,
(25) Goldberg, K. I.; Yan, J .; Breitung, E. M. J . Am. Chem. Soc. 1995,
117, 6889-6896.
(26) Goldberg, K. I.; Yan, J . Y.; Winter, E. L. J . Am. Chem. Soc.
1994, 116, 1573-1574.
(27) Appleton, T. G.; Hall, J . R.; Williams, M. A. J . Organomet.
Chem. 1986, 303, 139-149.
(28) Aye Khin, T.; Canty, A. J .; Crespo, M.; Puddephatt, R. J .; Scott,
J . D.; Watson, A. A. Organometallics 1989, 8, 1518-1522.
(29) Byers, P. K.; Canty, A. J .; Crespo, M.; Puddephatt, R. J .; Scott,
J . D. Organometallics 1988, 7, 1363-1367.
(30) Arsenault, G. J .; Crespo, M.; Puddephatt, R. J . Organometallics
1987, 6, 2255-2256.
(31) Monaghan, P. K.; Puddephatt, R. J . Organometallics 1984, 3,
444-449.
(32) Monaghan, P. K.; Puddephatt, R. J . Organometallics 1985, 4,
1406-1412.
(33) Graaf, W. d.; Boersma, J .; Koten, G. v. Organometallics 1990,
9, 1479-1484.
(35) Hughes, R. P.; Overby, J . S.; Williamson, A.; Lam, K.-C.;
Concolino, T. E.; Rheingold, A. L. Organometallics 2000, 19, 5190-
5201.
(34) Prokopchuck, E. M.; J enkins, H. A.; Puddephatt, R. J . Orga-
nometallics 1999, 18, 2861-2866.

3802 Organometallics, Vol. 20, No. 17, 2001
Hughes et al.
F igu r e 1. ORTEP diagram of the non-hydrogen atoms of
6a , showing atom-labeling scheme. Thermal ellipsoids are
shown at the 30% level.
and also couple to Pt with different coupling constants
2
(2J F1Pt ) 300 Hz, J F2Pt ) 251 Hz). These data indicate
that the product possesses no symmetry and are incon-
sistent with a trans adduct of structure 5, (Scheme 1)
in contrast to the reactions of the bis(dimethylphos-
phino)ethane analogue of 1 with fluoroalkyl iodides,
which do give analogous trans adducts.36 Of the two
possible cis adducts, structure 6a is confirmed by a
single-crystal X-ray diffraction study (see below) and is
assumed to be the solution structure. An ORTEP of the
structure of 6a is shown in Figure 1. Details of the
crystallographic determinations of all compounds in this
paper are presented in Table 1, and discussion of
structural details is deferred until later. An analogous
reaction occurs with C2F5I to afford the perfluoroethyl
complex 6b.
The oxidative addition reactions of fluoroalkyl iodides
to transition metals are unlikely to proceed via a polar
SN2 attack by the metal at carbon, due to the unfavor-
able polarity of the Cδ--Iδ+ bond.37,38 In previous
systems involving reactions of primary perfluoroalkyl
iodides we have postulated that these reactions proceed
via electron transfer to the fluoroalkyl iodide, followed
by rapid loss of iodide from the resultant radical anion,
and very fast trapping of the fluoroalkyl radical at the
metal.13,16 An analogous pathway in this case, shown
in Scheme 1 using perfluoro-n-propyl iodide, would
proceed via intermediate 7, which is indistinguishable
from that obtained by nucleophilic displacement at
carbon. Subsequent trapping of 7 by iodide would give
5, which is not observed, or 7 could undergo a rear-
rangement to 8 followed by trapping by iodide to afford
the observed product 6. Alternatively, the observed cis
stereochemistry may be the result of an initial, perhaps
concerted, cis oxidative addition or might be obtained
by initial trans oxidative addition to give 5, followed by
cis reductive elimination of CH3I to form 9a , which then
undergoes trans oxidative addition of CH3I to form
complex 6a . However, the latter sequence appears to
violate the principle of microscopic reversibility in
requiring a different stereochemistry for reductive
elimination and oxidative addition of CH3I. In addition,
(36) Hughes, R. P.; Sweetser, J . T.; Williamson, A.; Incarvito, C. D.;
Lam, K.-C.; Rheingold, A. L. Manuscript in preparation.
(37) Wakselman, C.; Lantz, A. In Organofluorine Chem; Banks, R.
E., Smart, B. E., Tatlow, J . C., Eds.; Plenum: New York, NY, 1994;
pp 177-194.
(38) Wakselman, C. J . Fluorine Chem. 1992, 59, 367-378.

Perfluoro-n-alkyl Complexes of Pt(II) and Pt(IV)
Organometallics, Vol. 20, No. 17, 2001 3803
Sch em e 1
9a , which can be prepared independently (see below),
is virtually insoluble in hexane, and treatment of a
suspension of 9a with CH3I results in no reaction,
although the reaction to form 6a proceeds smoothly in
CDCl3 solution. Consequently, the intermediacy of 9a
in the formation of 6a in hexanes seems unlikely.
Fortunately, the low solubility of complex 6a in hexanes
precludes it from undergoing further reactions (see
below) and allows it to be isolated in excellent yields.
On dissolution of complex 6a in acetone, CH2Cl2,
CHCl3, or toluene at room temperature, slow reversible
reductive elimination of CH3I occurs and an equilibrium
mixture of 6a and 9a is obtained after 24 h. The
equilibrium constant, measured at 21 °C, is 0.015 in
acetone-d6 or CDCl3 and 0.008 in toluene-d8. This
reaction presumably involves dissociation of iodide from
6a , followed by nucleophilic attack of iodide on the axial
methyl group of intermediate 8, i.e., the microscopic
reverse of the expected pathway for oxidative addition
of CH3I to 9a . Addition of excess Et3N to the equilibrium
mixture affords, after several hours, complete conver-
sion to [Et3NMe]I and 9a , which was isolated and
characterized by spectroscopic and crystallographic
methods (see below). The role of Et3N may be to shift
the equilibrium by reacting with eliminated CH3I to
produce [Et3NMe]I, or it may directly attack a methyl
ligand in cationic intermediate 8. We have no evidence
to distinguish between these possibilities in this system,
but observations outlined later suggest the latter path-
way. While no reaction between 9a and excess CH3I is
observed in hexanes, addition of excess CH3I to a
solution of 9a in CDCl3 affords complete conversion to
6a within 4 h, thereby confirming the stereochemistry
of oxidative addition of CH3I to 9a and, by microscopic
reversibility, the stereochemistry of reductive elimina-
tion from 6a .
F igu r e 2. ORTEP diagram of the non-hydrogen atoms of
9a , showing atom-labeling scheme. Thermal ellipsoids are
shown at the 30% level.
acterized crystallographically. An ORTEP of the struc-
ture of 9a is provided in Figure 2, and that of 9b in
Figure 3; details of the structures are discussed later.
In contrast to the clean reaction in hexanes, treatment
of 1 with n-C3F7I in THF solution affords a mixture of
several products. Compounds 9a and 10 were identified
as components of this mixture, but could only be isolated
in small quantities using this method; the best route to
9a is via 6a as described above. Complex 10 contains
no fluorinated ligand, and we have made no attempts
to identify its rather murky origins, but an ORTEP of
its structure is provided in Figure 4; details of the
structure are discussed later.
Attempts to prepare an analogue of the putative
cationic Pt(IV) intermediate 8 by treatment of 6a with
AgBF4 in toluene afforded a yellow solid 11 after workup
that appears to contain a water molecule in the sixth
coordination site; inclusion of a molecule of water
generates C and H percentages that agree well with the
experimental data, while omission of the water molecule
A similar equilibrium occurs with 6b, which can be
cleanly transformed to the Pt(II) compound 9b using
NEt3 in refluxing acetone. Complex 9b was also char-

3804 Organometallics, Vol. 20, No. 17, 2001
Hughes et al.
Sch em e 2
data for the presence of a coordinated water ligand. The
overall stereochemistry at Pt is retained in 11, as
evidenced by diastereotopic R- and â-CF2 groups and
inequivalent Pt-Me groups in the NMR spectra. In
addition, 11 reacts with NaCl to produce a correspond-
ing chloro analogue 12 that is isostructural with 6, as
indicated by 1H and 19F NMR spectroscopy. The fact
that the transformation of 6a f 11 f 12 can be
accomplished with retention of stereochemistry indi-
cates that the cation 8 is probably configurationally
stable.
Based on this accumulation of circumstantial evi-
dence, it seems that either the initial oxidative addition
of perfluoro-n-propyl iodide to give 6a occurs via an
overall concerted cis addition or the initially formed
cation 7 rearranges to 8 quickly compared to the rate
at which iodide reacts at platinum. However, analogous
cations containing basal methyl and axial perdeuterio-
methyl groups scramble via an analogous rearrange-
ment on a time scale reported to be slow compared to
the rate of trapping of the cation by iodide,40 so the
notion of a concerted addition in our case may not be
far fetched.
F igu r e 3. ORTEP diagram of the non-hydrogen atoms of
9b, showing atom-labeling scheme. Thermal ellipsoids are
shown at the 30% level.
Reaction of complex 9a with 1 equiv of I2 affords the
Pt(IV) product (TMEDA)Pt(n-C3F7)(CH3)I2, 13, as a deep
red crystalline solid (Scheme 2). Proton NMR spectros-
copy shows only two environments for the NMe groups,
indicating that the two iodide ligands are either both
trans or both cis; the trans configuration is confirmed
by X-ray crystallography, and an ORTEP is shown in
Figure 5.
In contrast to 6a , with a labile iodide trans to a CH3
ligand, the iodide in complex 13 is far less labile, and
reductive elimination of CH3I in CDCl3 solution is very
slow, forming an approximately 1:1 mixture with 14
F igu r e 4. ORTEP diagram of the non-hydrogen atoms of
10, showing atom-labeling scheme. Thermal ellipsoids are
shown at the 30% level.
(39) Hughes, R. P.; Lindner, D. C.; Smith, J . M.; Zhang, D.; Incarvito,
C. D.; Lam, K.-C.; Liable-Sands, L. M.; Sommer, R. D.; Rheingold, A.
L. J . Chem. Soc., Dalton Trans. 2001, in press.
(40) J enkins, H. A.; Yap, G. P. A.; Puddephatt, R. J . Organometallics
1997, 16, 1946-1955.
puts the values outside acceptable limits, but, unlike
many other fluoroalkyl(aqua) complexes we have pre-
pared,4,5,39 we cannot provide unambiguous IR or NMR

Perfluoro-n-alkyl Complexes of Pt(II) and Pt(IV)
Organometallics, Vol. 20, No. 17, 2001 3805
Sch em e 3
F igu r e 5. ORTEP diagram of the non-hydrogen atoms of
13, showing atom-labeling scheme. Thermal ellipsoids are
shown at the 30% level.
after 3 weeks. Addition of excess NaI in EtOH only
slightly accelerates the conversion of 13 to 14, which is
complete after 4 weeks. However, reaction of 13 with
AgBF4 followed by addition of NaI cleanly produces the
Pt(II) complex 14 as a yellow solid. We assume that this
reaction proceeds by initial removal of one of the iodide
ligands by Ag+ to form cation 15, which, on addition of
iodide nucleophile, rapidly eliminates CH3I via attack
at CH3 to form 14. We must also assume that cation 15
can rearrange to isomer 16 with an axial methyl in order
for such a nucleophilic attack to produce square planar
14. This cation rearrangement is analogous to that
proposed for the conversion of 7 to 8 during formation
of 6a (vide supra). The observation that elimination of
CH3I from 16 does not occur without added nucleophile
(I-) suggests that it is direct nucleophilic attack on the
CH3 group of 16 that is responsible for reductive
elimination.25,41 Analogous nucleophilic attack by water
on the CH3 ligand of a cationic Pt(IV) intermediate has
been identified as a key step in the reductive elimination
of methanol.42
F igu r e 6. ORTEP diagram of the non-hydrogen atoms of
18, showing atom-labeling scheme. Thermal ellipsoids are
shown at the 30% level.
hours, with a second compound, presumably [(TMEDA)-
Pt(C3F7){(CD3)2CO}]OTf. Addition of excess H2O re-
forms 17. This cationic complex reacts with iodide to
afford the iodo(fluoropropyl) complex 14. Complex 14
reacts with NaBH4 in EtOH solution to produce the
hydride complex 18, which has a metal hydride reso-
nance at δ -20.96 ppm and a Pt-H stretch in the IR
spectrum at 2197 cm-1. This compound has also been
characterized crystallographically, and an ORTEP is
shown in Figure 6.
P er flu or oa lk yl P t(II) Com p lexes w ith Dip h os-
p h in e Liga n d s. The TMEDA ligand in these Pt(II)
complexes can be displaced by chelating diphosphine
ligands, as shown in Scheme 3. Complex 9a reacts with
1,2-bis(diphenylphosphino)ethane (DPPE) in refluxing
toluene to afford the corresponding diphosphine ana-
logue 19; the structure of 19 was confirmed crystallo-
graphically, and an ORTEP is shown in Figure 7.
Treatment of 19 with HOTf affords a white solid triflate
complex 20, presumably with liberation of methane; no
elimination of fluoroalkane was observed. The structure
of 20 was also confirmed crystallographically, and an
ORTEP is presented in Figure 8. In moist CD2Cl2
Reaction of complex 9a with CF3SO3H (HOTf) in moist
CH2Cl2 produces the cationic Pt(II) complex 17, which
forms an equilibrium in acetone-d6 solution, after a few
(41) Crumpton, D. M.; Goldberg, K. I. J . Am. Chem. Soc. 2000, 122,
962-963.
(42) Luinstra, G. A.; Labinger, J . A.; Bercaw, J . E. J . Am. Chem.
Soc. 1993, 115, 3004-3005.

3806 Organometallics, Vol. 20, No. 17, 2001
Hughes et al.
F igu r e 9. ORTEP diagram of the non-hydrogen atoms of
one of the two independent molecules of 23, showing atom-
labeling scheme. Only the ipso-carbons of each phenyl ring
are shown for clarity. Thermal ellipsoids are shown at the
30% level.
F igu r e 7. ORTEP diagram of the non-hydrogen atoms of
19, showing atom-labeling scheme. Only the ipso-carbons
of each phenyl ring are shown for clarity. Thermal el-
lipsoids are shown at the 30% level.
reaction of the triflate complex 20 with sodium iodide.
Clearly, elimination of CH3I from a Pt(IV) intermediate
is more facile with DPPE as a ligand than with TMEDA.
This may be a steric effect, as we observe that analogous
eliminations from 1,2-(dimethylphosphino)ethane Pt(IV)
complexes are actually more difficult than from TMEDA
analogues.43 Treatment of 22 with NaBH4 in ethanol
affords the hydride complex 23 in high yield. A similar
complex, (DPPE)Pt(CF3)H, has been prepared in a
similar manner.44-47 The proton and fluorine NMR
spectra of 23 show complex coupling patterns. The
hydride couples with the platinum (J ) 1209 Hz), the
trans-phosphorus (J ) 189 Hz), the cis-phosphorus
(J ) 15 Hz), the R-CF2 (J ) 7.5 Hz), and the â-CF2 (J )
6.5 Hz). The R-CF2 couples with the platinum (J ) 379
Hz), the trans-phosphorus (J ) 32.6 Hz), the cis-
phosphorus (J ) 31.7 Hz), the CF3 (J ) 10 Hz), and the
3
hydride (J ) 7.5 Hz). In fluoroalkyl groups J FF is often
close to zero48 and is not observed in our compounds.
Interestingly, the â-CF2 couples with the platinum
(J ) 150 Hz), the hydride (J ) 6.5 Hz), and only to the
cis-phosphorus (J ) 7.3 Hz). This particular phosphorus,
which is also trans to the hydride ligand, can be
unambiguously assigned by using non-proton-decoupled
31P NMR; it has the large coupling to the hydride, as
expected. The structure of 23 was confirmed by X-ray
crystallography. The compound crystallizes with two
independent molecules in the asymmetric unit; an
ORTEP of one molecule is shown in Figure 9.
F igu r e 8. ORTEP diagram of the non-hydrogen atoms of
20, showing atom-labeling scheme. Only the ipso-carbons
of each phenyl ring are shown for clarity. Thermal el-
lipsoids are shown at the 30% level.
solution at room temperature the 19F NMR spectrum
of this complex shows two sets of broad resonances for
the triflate and fluoroalkyl ligands in an approximately
1:1 ratio. We attribute this behavior to the presence of
an equilibrium between 20 and a water complex 21,
analogous to the TMEDA analogue 17. Cooling the
sample or addition of water to the NMR sample at room
temperature shifts the equilibrium toward 21. However,
unlike the TMEDA analogue 17, it is the coordinated
triflate complex 20 that crystallizes, even from moist
solvents, perhaps illustrating the difference in affinity
for water between the harder (TMEDA)Pt center com-
pared to the softer (DPPE)Pt analogue.
It is noteworthy that none of the water complexes 11,
17, or 21 show any evidence of hydrolysis reactions of
(43) Hughes, R. P.; Sweetser, J . T.; Tawa, M. D.; Williamson, A.
Unpublished observations.
(44) Michelin, R. A.; Ros, R.; Guadalupi, G.; Bombieri, G.; Benetollo,
F.; Chapuis, G. Inorg. Chem. 1989, 28, 840-846.
(45) Michelin, R. A.; Belluco, U.; Ros, R. Inorg. Chim. Acta 1977,
24, L33-L34.
(46) Michelin, R. A.; Facchin, G.; Ros, R. J . Organomet. Chem. 1985,
279, C25-C28.
In contrast to the reaction of the TMEDA analogue
9a with I2, to afford the Pt(IV) complex 13, reaction of
the DPPE complex 19 with I2 affords only the Pt(II)
complex 22, which can also be prepared cleanly by
(47) Del Pra, A.; Zanotti, G.; Bardi, R.; Belluco, U.; Michelin, R. A.
Cryst. Struct. Commun. 1979, 8, 729-736.
(48) Emsley, J . W.; Phillips, L.; Wray, V. Fluorine Coupling Con-
stants; Pergamon: Oxford, 1977.

Perfluoro-n-alkyl Complexes of Pt(II) and Pt(IV)
Organometallics, Vol. 20, No. 17, 2001 3807
Ta ble 2. Selected Bon d Len gth s (Å) a n d An gles (d eg) for th e Coor d in a tion Sp h er es of P d (II)- a n d
P t(II)-F lu or oa lk yl Com p lexes
3a 35
3b35
9a
9b
18
19
20
23
Pt-X(1)
Pt-C(2)
Pt-E(1)
Pt-E(2)
X(1)-Pt-C(2) 86.8(4), 87.2(4)
E(1)-Pt-E(2) 82.1(3), 82.6(3)
X(1)-Pt-E(2) 92.6(4), 91.7(4)
C(2)-Pt-E(1) 98.6(3), 98.6(4)
2.106(10), 2.078(10 2.052(5) 2.148(18)a 2.060(5)a
b
2.108(7)a
2.067(7)
2.142(4)c
2.087(6)
b
1.996(9), 1.970(11)
2.222(8), 2.228(8)
2.162(9), 2.139(9)
1.990(5) 2.01(2)
2.235(4) 2.14(2)d
1.995(4)
2.205(4)d
1.996(10)
2.049(13), 2.074(14)
2.155(10)d 2.2984(19)e 2.2062(14)e 2.331(3),e 2.313(3)e
2.167(4) 2.172(19)d 2.161(3)d
2.123(8)d
b
2.2832(19)e 2.3094(14)e 2.264(3),e 2.259(3)e
87.7(2)
82.39(18) 81.7(8)d
92.0(2) 92.3(8)
97.97(19) 97.7(9)
88.3(9)
89.02(18)a
89.0(3)a
84.91(7)e
92.3(2)
93.8(2)
86.0(2)a
85.34(5)e
94.85(11)
93.8(2)
b
82.72(14)d 82.4(3)d
85.47(12),e 85.57(11)e
91.09(17)
b
b
97.21(15) 100.2(4)
99.3(4), 98.6(4)
a
b
d
X ) CH3. X ) H. c X ) O. E ) N. e E ) P.
the R-CF2 groups, as has been observed in analogous
fluoroalkyl(aqua) cations of Rh(III).4 Furthermore, treat-
ment of the water complexes 11, 17, or 21 or the triflate
complex 20 with H2 results in no reaction, affording no
evidence of any hydrogenolysis of the R-CF2 bonds, as
has been observed in analogous compounds of Ir(III).5
It seems clear that fluorines on a carbon R to Pt(II) or
Pt(IV) are much less labile than those R to Rh(III) or
Ir(III).
observed as a sharp singlet with platinum satellites and
the R-CF2 has also begun to sharpen to a singlet.
Similar behavior is observed for 9a , in which the
R-CF2 resonance at room temperature is broad in CD2-
Cl2 solution. At -70 °C both the R- and â-CF2 reso-
nances separate into four sharp doublet resonances,
with a large coupling between the two individual â-CF2
fluorines (2J FF ) 284 Hz) and between the two indi-
vidual R-CF2 fluorines (2J FF ) 272 Hz). While the
platinum satellites for the â-CF2 fluorines are broad and
appear as narrow shoulders, those for the R-CF2 fluo-
rines are only slightly broadened and are dramatically
different for each fluorine atom (2J F1Pt ) 535 Hz,
2J F2Pt ) 285 Hz). The F-Pt coupling constant for the
R-CF2 group at room temperature is the approximate
mean of these two values (2J FPt ) 429 Hz). The separa-
tion between the two R-CF2 resonances at -70 °C is 5.5
Dyn a m ic Beh a vior of th e TMEDA Rin gs. We have
shown previously that the 19F NMR spectra of palladium
complexes 3 and 4 are temperature dependent, due to
a slowing of the ring pucker inversion of the TMEDA
ring at low temperatures, a process with ∆Gq ) 11-13
kcal mol-1 35
In a puckered ring ground state there is a
.
stereocenter at the metal, and the R-CF2 and â-CF2
groups contain diastereotopic fluorines. At low temper-
atures each pair of diastereotopic fluorines appears as
a well-separated, and strongly coupled, AX spin system,
each of which coalesces as the temperature is raised.
In iodo complex 4 the chemical shift difference between
the R-CF2 fluorines is so large (∼35 ppm at 470 MHz)
that their coalescence temperature is close to ambient,
and at room temperature the R-CF2 resonance is invis-
ible.
1
ppm. The H NMR spectra of 9a at room temperature
and at -70 °C both show only two environments for the
NMe groups, indicating that the chemical shift differ-
ence is small and decoalescence has not yet occurred.
However, the -70 °C spectrum shows four separate
environments for the hydrogens of the CH2CH2 back-
bone and very broad Pt-satellites.
The room-temperature 19F NMR spectrum of the
hydrido analogue 18 in CD2Cl2 is sharp. However, on
cooling to -20 °C, the resonances corresponding to the
R- and â-CF2 fluorines begin to broaden, and at -75 °C
the R-CF2 fluorines appear as two doublets (2J FF ) 276
Hz) with different platinum couplings (2J F1Pt ) 384 Hz,
2J F2Pt ) 328 Hz), though not as dramatically different
as those in 9a . In contrast to 14 and 9a , the diastereo-
topic R-CF2 resonances are only separated by 1.4 ppm.
The Pt(IV) complex 13 has the same symmetry as 14,
and its 19F NMR spectrum at room temperature shows
equivalent fluorines within each CF2 group. On cooling
to -20 °C, the resonances corresponding to the R- and
â-CF2 groups start to become broad and at -70 °C
separate into four broad humps. The TMEDA ring
puckering process in this platinum(IV) complex appears
to be more facile than that in the Pt(II) analogues.
Str u ctu r a l Com p a r ison s. Details of the crystal
structure determinations of all compounds determined
here are presented in Table 1. Selected bond lengths
and angles for the square planar Pt(II) compounds are
presented in Table 2, along with comparison data for
3a and 3b. Analogous values for octahedral Pt(IV)
compounds appear in Table 3. To allow for easy com-
parison, in each series a common numbering system is
used, with atom X(1) [X ) CH3, H, O] always trans to
E(1) (E ) N, P), and atom C(2) (the R-carbon of the
fluorinated ligand) always trans to E(2). In the Pt(IV)
Like its palladium analogue 4,35 the room-tempera-
ture 19F NMR spectrum of 14 in toluene-d8 shows only
a CF3 triplet and a broad â-CF2 singlet. As pointed out
3
earlier, in fluoroalkyl groups J FF is often close to zero48
and is unobserved in our compounds. Consequently, the
4
CF3 triplet arises from a J coupling to the R-CF2 rather
than to the â-CF2 fluorines, but the R-CF2 resonance
itself is not observed. On progressive cooling, the â-CF2
resonance separates into two doublets corresponding to
two diastereotopic fluorines, and two broad humps begin
to appear, corresponding to two diastereotopic R-CF2
fluorines. At -60 °C these become two sharp doublets,
well separated by 29.8 ppm (at 470 MHz), but with
platinum satellites still too broad to observe, probably
due to chemical shift anisotropy effects that have been
well documented in other compounds.49-55 When the
sample of 14 is heated to 90 °C, the â-CF2 fluorines are
(49) Skvortsov, A. N. Russ. J . Gen. Chem. 2000, 70, 1023-1027.
(50) Ghosh, P.; Desrosiers, P. J .; Parkin, G. J . Am. Chem. Soc. 1998,
120, 10416-10422.
(51) Gay, I. D.; Young, G. B. Organometallics 1996, 15, 2264-2269.
(52) Lindner, E.; Fawzi, R.; Mayer, H. A.; Eichele, K.; Hiller, W.
Organometallics 1992, 11, 1033-1043.
(53) Ismail, I. M.; Kerrison, S. J . S.; Sadler, P. J . Polyhedron 1982,
1, 57-59.
(54) Doddrell, D. M.; Barron, P. F.; Clegg, D. E.; Bowie, C. J . Chem.
Soc., Chem. Commun. 1982, 575-576.
(55) Lallemand, J . Y.; Soulie, J .; Chottard, J . C. J . Chem. Soc., Chem.
Commun. 1980, 436-438.

3808 Organometallics, Vol. 20, No. 17, 2001
Hughes et al.
Ta ble 3. Selected Bon d Len gth s (Å) a n d An gles
(d eg) for th e Coor d in a tion Sp h er e of
P t(IV)-F lu or oa lk yl Com p lexes
determining trans influences. However it is also inter-
esting that, in a comparison of 19 and 23, the Pt-P(1)
distance trans to H in 23 is significantly longer than
that trans to CH3 in 19, exactly the opposite of the
observation in the TMEDA analogues discussed above.
The Pt-P(2) bond cis to H in 23 is shorter than that cis
to CH3 in 19, once again illustrating that cis steric
influences may be more important than any trans
influences in determining bond distances. The Pt-P(1)
distance in triflate complex 20 illustrates that triflate
has a weaker trans influence than CH3 or H, but the
lengthening of the Pt-P(2) distance in 20 compared to
those in 19 and 23 is most likely a reflection of the larger
steric demand of triflate.
The series of octahedral Pt(IV) complexes 6a , 10, and
13 (Table 3) provide analogous comparisons within the
series and also with their square planar Pt(II) analogues
(Table 2). In each of 6a and 13 the Pt distances to
fluoroalkyl and CH3 are no longer significantly different,
but the bonds to the N still reflect the lower trans
influence of fluoroalkyl compared to CH3 in each com-
pound. All bonds in the “equatorial” plane of 13 are
longer than those in 6a , probably reflecting the steric
effects of two “axial” iodides in the former compound
compared to a single iodide and a methyl in the latter.
The Pt-CH3 distance in 10 is identical to that in 13
and longer than that in 6a , probably for the same
reason. Once again it is difficult to separate steric effects
from any electronic effects on bond distances.
6a
10
13
Pt-C(1)
2.064(9)
2.050(6)
2.077(6)
2.275(7)
2.226(5)
2.8037(5)
2.092(14)
2.098(10)
2.083(9)
Pt-C(2)
Pt-C(1A)
Pt-N(1)
2.282(11)
2.312(7)
2.262(7)
2.6936(6)
2.6916(6)
96.6(3)
82.3(2)
88.5(3)
92.6(3)
Pt-N(2)
Pt-I(1)
2.6731(10)
Pt-I(2)
C(1)-Pt-C(2)
N(1)-Pt-N(2)
C(1)-Pt-N(2)
C(2)-Pt-N(1)
C(1A)-Pt(1)-N(1)
C(2)-Pt(1)-I(1)
C(1)-Pt(1)-I(1)
N(2)-Pt(1)-I(1)
N(1)-Pt(1)-I(1)
95.4(3)
82.5(2)
89.5(3)
92.7(2)
92.2(3)
89.81(17)
85.9(2)
93.77(13)
93.15(15)
91.4(10)
82.8(5)
92.9(6)
88.5(2)
84.6(2)
92.37(17)
93.97(12)
85.9(4)
93.2(3)
96.4(3)
complexes the “equatorial plane” is used to mean the
plane corresponding to N(1) and N(2) and the two atoms
trans to them. Two sets of data are presented for 23,
corresponding to the two independent molecules in the
asymmetric unit.
We have presented elsewhere a discussion of the
structural trans influences56 of perfluoroalkyl and meth-
yl ligands in (TMEDA)Pd complexes 3.35 The structure
of 9a is of sufficiently poor quality to preclude meaning-
ful comparisons, but its perfluoroethyl analogue 9b
illustrates the expected shorter bond to the fluoroalky-
lated carbon than to the CH3 ligand, and the lower trans
influence of fluoroalkyl compared to methyl. Comparison
with the structure of Pd analogue 3b illustrates that
the compounds are virtually identical in terms of bond
lengths to the metal center. Comparison of 9b with the
hydrido complex 18 is also interesting; the Pt-fluoro-
alkyl distance remains unchanged, but both Pt-N
distances are significantly shorter in 18 than in 9b. The
shortening of the Pt-N(2) distance trans to RF may
reflect the reduced steric demand of the cis ligand H
relative to CH3, while the corresponding shortening of
the Pt-N(1) distance may reflect a weaker trans influ-
ence of H relative to CH3 in these systems. These
differences also illustrate the difficulty of isolating cis
steric influences from trans electronic influences in
comparing bond distances and emphasize the dangers
of overinterpretation of bond length data.
Some useful comparisons can be made with the series
of DPPE analogues. Comparison of 9b with 19 shows
that both Pt-C bonds are significantly longer in the
diphosphine complex, perhaps reflecting the greater
trans influence of P compared to N, but perhaps also
reflecting a difference in cis steric influences of the two
chelating ligands. The Pt-fluoroalkyl distance is still
shorter than the Pt-CH3 distance, and the fluoroalkyl
trans influence is still weaker than the corresponding
influence of CH3. Therefore, the order of trans influences
of fluoroalkyl versus CH3 holds for diamine ligands,
which cannot be π-acceptors, and diphosphine ligands,
which can. This supports the proposal57 that π-acceptor
properties of ligands are relatively unimportant in
Exp er im en ta l Section
Gen er a l Con sid er a tion s. Unless otherwise noted, all
reactions were performed in oven-dried glassware, using
standard Schlenk techniques, under an atmosphere of nitro-
gen, which had been deoxygenated over BASF catalyst and
dried using Aquasorb, or using drybox techniques. THF,
diethyl ether, hexanes, and CH2Cl2 were dried and degassed
over alumina columns under N2.58 1H NMR (300 MHz) and
19F (282 MHz) were recorded on a Varian UNITY plus 300
system in the solvent indicated. Variable-temperature1H (500
MHz) and 19F (470 MHz) NMR spectra were recorded on a
Varian UNITY plus 500 system in the solvent indicated.
1HNMR chemical shifts were referenced to TMS using the
protio impurity in the solvent peak, and 19F chemical shifts
were referenced to CFCl3. Microanalyses were performed by
Schwarzkopf Microanalytical Laboratory (Woodside, NY).
Perfluoroalkyl iodides were purchased from Aldrich, treated
with Na2S2O3 to remove residual I2, and vacuum distilled
before use. (TMEDA)Pt(CH3)2 was prepared according to a
literature procedure.59
(TMEDA)P t(n -C3F 7)(CH3)2I (6a ). To a stirring suspension
of (TMEDA)Pt(CH3)2 (0.564 g, 1.65 mmol) in hexanes (20 mL)
was added n-C3F7I (0.40 mL, 2.77 mmol). The solid rapidly
dissolved to form a yellow solution, followed by slow precipita-
tion of a white solid. The mixture was stirred for 16 h and
then filtered. The solid residue was washed with hexanes and
air-dried. Yield: 0.854 g, 81%. Anal. Calcd for C11H22F7IN2Pt:
C, 20.73; H, 3.48; N, 4.39. Found: C, 20.80; H, 3.47; N, 4.34.
1H NMR (CDCl3, 300 MHz, 23 °C): δ 1.42 (m, 3H, 2J HPt ) 64.2
4
2
Hz, PtMe), 1.74 (t, J HF ) 2.0 Hz, 3H, J HPt ) 69.3 Hz, PtMe),
3
3
2.42 (s, 3H, J HPt ) 18.6 Hz, NMe), 2.61 (s, 3H, J HPt ) 12.9
Hz, NMe), 2.61-3.90 (m, 4H, CH2), 3.30 (s, 3H, J HPt ) 15.0
3
(56) Appleton, T. G.; Clark, H. C.; Manzer, L. E. Coord. Chem. Rev.
1973, 10, 335-422.
(57) Landis, C. R.; Firman, T. K.; Root, D. M.; Cleveland, T. J . Am.
Chem. Soc. 1998, 120, 1842-1854.
(58) Pangborn, A. B.; Giardello, M. A.; Grubbs, R. H.; Rosen, R. K.;
Timmers, F. J . Organometallics 1996, 15, 1518-1520.
(59) Yang, D. S.; Bancroft, G. M.; Dignard-Bailey, L.; Puddephatt,
R. J .; Tse, J . S. Inorg. Chem. 1990, 29, 2487-2495.

Perfluoro-n-alkyl Complexes of Pt(II) and Pt(IV)
Organometallics, Vol. 20, No. 17, 2001 3809
Hz, NMe), 3.35 (s, 3H, 3J HPt ) 9.3 Hz, NMe). 19F NMR (CDCl3,
282.2 MHz, 23 °C): δ -119.9 (d,2J FF ) 284 Hz, â-CF), -117.2
tate of (Et3NMe)I was removed by filtration and the resultant
filtrate reduced in vacuo to afford a yellow solid. Yield: 0.082
g, 99%. Anal. Calcd for C10H19F7N2Pt: C, 24.25; H, 3.84; N,
2
2
2
(d, J FF ) 284 Hz, â-CF), -81.1 (dm, J FF ) 257 Hz, J FPt
)
4
4
1
300 Hz, R-CF), -79.6 (t, J FF ) 13 Hz, J FPt ) 20 Hz, CF3),
5.65. Found: C, 24.22; H, 3.84; N, 5.65. H NMR (CDCl3, 300
2
2
4
2
-64.6 (dm, J FF ) 257 Hz, J FPt ) 251 Hz, R-CF). Crystals for
the structure determination were obtained from CH2Cl2-
hexane at -20 °C as yellow blocks.
MHz, 23 °C): δ 0.50 (tt, J HF ) )
5J HF ) 1.5 Hz, 3H, J HPt
86.1 Hz, PtMe), 2.64 (s, 6H, 3J HPt ) 26.1 Hz, NMe), 2.54-2.73
(m, 4H, CH2), 2.77 (s, 6H, 3J HPt ) 18 Hz, NMe). 1H NMR (CD2-
Cl2, 500 MHz, -70 °C): δ 0.25 (s, 3H, PtMe), 2.24 (br d,
J HH ) 11 Hz, 1H, CH2), 2.41 (br d, J HH ) 11 Hz, 1H, CH2),
2.56 (s, 6H, NMe), 2.66 (s, 6H, NMe), 2.83 (br t, J HH ) 13 Hz,
1H, CH2), 2.92 (br t, J HH ) 13 Hz, 1H, CH2). 19F NMR (CDCl3,
(TMEDA)P t(C2F 5)(CH3)2I (6b). To a suspension of (TM-
EDA)Pt(CH3)2 (0.100 g, 0.293 mmol) in hexanes (20 mL) was
added CF3CF2I (0.2 g, 0.82 mmol). The mixture was stirred
overnight at room temperature in the absence of light. The
resulting white suspension was filtered, and the residue was
washed with hexanes (3 × 5 mL). The white solid was
dissolved in CH2Cl2 (5 mL) and filtered through Celite. The
colorless filtrate was collected, and the product was precipi-
tated upon addition of hexanes (20 mL). The white solid was
dried in vacuo to give the product, 0.143 g, 83%. Anal. Calcd
for C10H22F5IN2Pt: C 20.45, H 3.78. Found: C 20.60, H 3.64.
3
300 MHz, 23 °C): δ -118.2 (s, J FPt ) 118 Hz, â-CF2), -90.3
2
4
4
(br s, J FPt ) 429 Hz, R-CF2), -79.7 (t, J FF ) 11 Hz, J FPt
)
36 Hz, CF3). 19F NMR (CD2Cl2, 470.4 MHz, -70 °C): δ -117.9
2
2
(d, J FF ) 284 Hz, â-CF), -114.8 (d, J FF ) 284 Hz, â-CF),
2
2
-92.1 (d, J FF ) 272 Hz, J FPt ) 285 Hz, R-CF), -86.6 (d,
2J FF ) 272 Hz, J FPt ) 535 Hz, R-CF), -77.8 (t, J FF ) 10.5
2
4
Hz, CF3).
2
1H NMR (C6D6, 300 MHz, 23 °C): δ 1.09 (d, J HPt ) 64 Hz,
(TMEDA)P t(C2F 5)(CH3) (9b). To a solution of (TMEDA)-
Pt(C2F5)(CH3)2I (0.101 g, 0.172 mmol) in acetone (20 mL) was
added Et3N (2.0 mL, 14 mmol). The colorless solution was
stirred overnight under reflux. The solution was cooled to room
temperature, and the volatiles were removed in vacuo to yield
a white solid. The solid was extracted into Et2O and filtered
through Celite. The filtrate was collected, and the volatiles
were removed in vacuo to yield the product as a white solid
(0.070 g, 91%). Anal. Calcd for C9H19F5N2Pt: C 24.27, H 4.30.
4J HF ) 2 Hz, 3H, PtCH3), 1.34-1.55 (m, 2H, CH2), 1.39 (s,
2
3J HPt ) 18 Hz, 3H, NCH3), 1.82 (s, J HPt ) 70 Hz, 3H, PtCH3),
3
1.87 (s, J HPt ) 13 Hz, 3H, NCH3), 1.97-2.18 (m, 2H, CH2),
3
3
2.74 (s, J HPt ) 15 Hz, 3H, NCH3), 3.01 (s, J HPt ) 10 Hz, 3H,
NCH3). 19F NMR (C6D6, 282.2 MHz, 23 °C): δ -83.7 (d,
2J FPt ) 331 Hz, J FF ) 252 Hz, CF), -77.3 (s, CF3), -70.2 (d,
2
2J FF ) 252 Hz, J FPt ) 245 Hz, CF).
2
[(TMEDA)P t(n -C3F 7)(CH3)2(OH2)]BF 4 (11). On addition
of toluene (15 mL) to a mixture of (TMEDA)Pt(n-C3F7)(CH3)2I
(0.101 g, 0.158 mmol) and AgBF4 (0.045 g, 0.23 mmol) a pale
yellow suspension was formed. The mixture was stirred for
16 h and then filtered through Celite, which was washed
further with CH2Cl2. The solvent was removed in vacuo from
the resultant filtrate to give a white solid, which was washed
with CHCl3. Yield: 0.088 g, 90%. Anal. Calcd for C11H24BF11N2-
OPt: C, 21.48; H, 3.93; N, 4.55. Found: C, 21.63; H, 4.36;
N, 4.42. 1H NMR (CD2Cl2, 300 MHz, 23 °C): δ 1.34 (s, 3H,
1
Found: C 24.17, H 4.20. H NMR (C6D6, 300 MHz, 23 °C): δ
0.97 (tq, 2J HPt ) 88 Hz, 4J HF ) 1 Hz, 5J HF ) 1 Hz, 3H, PtCH3),
1.34-1.44 (m, 4H, CH2CH2), 1.80 (s, 3J HPt ) 25 Hz, 6H, NCH3),
2.27 (s, 3J HPt ) 18 Hz, 6H, NCH3). 19F NMR (C6D6, 282.2 MHz,
2
3
23 °C): δ -93.6 (s, J FPt ) 426 Hz, CF2), -81.0 (s, J FPt ) 65
Hz, CF3).
(TMEDA)P t(n -C3F 7)(CH3)I2 (13). Addition of hexanes (15
mL) to a mixture of (TMEDA)Pt(n-C3F7)(CH3) (0.200 g, 0.404
mmol) and I2 (0.103 g, 0.406 mmol) followed by stirring for 3
h gave an orange-brown precipitate in a purple solution. The
solid was collected on a glass frit and washed repeatedly with
hexanes. Yield: 0.249 g, 82%. Anal. Calcd for C10H19F7I2N2Pt:
C, 16.03; H, 2.56; N, 3.74. Found: C, 16.13; H, 2.46; N, 3.65.
2
2J HPt ) 76 Hz, PtMe), 1.34 (s, 3H, J HPt ) 66 Hz, PtMe), 2.49
3
3
(s, 3H, J HPt ) 22.5 Hz, NMe), 2.58 (s, 3H, J HPt ) 14.4 Hz,
NMe), 2.66-3.22 (m, 10H, NMe and CH2). 19F NMR (CD2Cl2,
2
282.2 MHz, 23 °C): δ -149.9 (s, BF4), -121.3 (dd, J FF ) 289
Hz, 3J FF ) 14 Hz, â-CF), -119.9 (d, 2J FF ) 289 Hz, â-CF), -91.8
2
1H NMR (CDCl3, 300 MHz, 23 °C): δ 2.87 (t, J HF ) 2.1 Hz,
2
3
4
2
2
(ddq, J FF ) 272 Hz, J FF ) 14 Hz, J FF ) 13 Hz, J FPt ) 389
3H, J HPt ) 71.7 Hz, PtMe), 2.87-3.05 (m, 4H, CH2), 3.29 (s,
2
2
6H, 3J HPt ) 18.0 Hz, NMe), 3.31 (s, 6H, 3J HPt ) 12.6 Hz, NMe).
19F NMR (CDCl3, 282.2 MHz, 23 °C): δ -116.0 (s, â-CF2),
Hz, R-CF), -89.3 (dm, J FF ) 272 Hz, J FPt ) 220 Hz, R-CF),
4
4
-80.1 (t, J FF ) 13 Hz, J FPt ) 16 Hz, CF3).
4
4
4
-79.4 (t, J FF ) 13 Hz, J FPt ) 15 Hz, CF3), -48.8 (q, J FF
)
(TMEDA)P t(n -C3F 7)(CH3)2Cl (12). Addition of CH2Cl2 (15
mL) to a mixture of (TMEDA)Pt(n-C3F7)(CH3)2I (0.200 g, 0.319
mmol) and AgBF4 (0.080 g, 0.411 mmol) gave a yellow
precipitate of AgI. The mixture was stirred for 1 h, and then
a solution of NaCl (0.3 g, excess) in EtOH/H2O was added.
After stirring for 30 min the volatiles were removed in vacuo
and the solid residue was extracted into CH2Cl2 and then
filtered through Celite. Removal of solvent in vacuo gave a
white solid. Yield: 0.165 g, 96%. Anal. Calcd for C11H22ClF7N2-
Pt: C, 24.20; H, 4.06; N, 5.13. Found: C, 23.98; H, 4.13; N,
2
13 Hz, J FPt ) 251 Hz, R-CF2). Crystals for the structure
determination were obtained from CH2Cl2/heptane as dark red
blocks.
(TMEDA)P t(n -C3F 7)I (14). Addition of moist CH2Cl2 (15
mL) to a mixture of (TMEDA)Pt(C3F7)(CH3)I2 (0.194 g, 0.259
mmol) and AgBF4 (0.111 g, 0.570 mmol) gave a pale yellow
precipitate in a colorless solution. The mixture was stirred for
30 min, and then a solution of NaI (0.20 g, excess) in H2O (5
mL) was added and the resultant slurry stirred for 90 min.
The organic layer was separated, dried over anhydrous Na2-
SO4, and filtered through Celite to give pale yellow solution.
Removal of solvent in vacuo afforded a yellow solid. Yield:
0.146 g, 93%. Anal. Calcd for C9H16F7IN2Pt: C, 17.80; H, 2.66;
5.07. 1H NMR (CDCl3, 300 MHz, 23 °C): δ 1.12 (d, 3H, 4J HF
)
2.7 Hz, 2J HPt ) 69 Hz, PtMe), 1.36 (s, 3H, 2J HPt ) 69 Hz, PtMe),
3
3
2.43 (s, 3H, J HPt ) 19.5 Hz, NMe), 2.54 (s, 3H, J HPt ) 12.6
3
Hz, NMe), 2.84 (s, 3H, J HPt ) 13.5 Hz, NMe), 2.99 (s, 3H,
3J HPt ) 8.4 Hz, NMe), 2.38-3.14 (m, 4H, CH2). 19F NMR
1
N, 4.61. Found: C, 17.95; H, 2.63; N, 4.59. H NMR (CDCl3,
2
(CDCl3, 282.2 MHz, 23 °C): δ -121.1 (dd, J FF ) 289 Hz,
300 MHz, 23 °C): δ 2.62-2.76 (m, 4H, CH2), 2.92 (brs, 6H,
3J FF ) 13 Hz, â-CF), -119.0 (ddd, J FF ) 289 Hz, J FF ) 12
2
3
3
3J HPt ) 17.4 Hz, NMe), 2.98 (br s, 6H, J HPt ) 45.0 Hz, NMe).
3
2
3
1H NMR (toluene-d8, 500 MHz, -70 °C): δ 0.53 (br d, J HH
)
Hz, J FF ) 8 Hz, â-CF), -86.6 (ddq, J FF ) 270 Hz, J FF ) 12
4
2
Hz, J FF ) 13.5 Hz, J FPt ) 388 Hz, R-CF), -83.2 (dddq,
12 Hz, CH2), 0.72 (br d, J HH ) 12 Hz, 1H, CH2), 1.66 (br t,
J HH ) 12 Hz, 1H, CH2), 1.93 (br t, J HH ) 12 Hz, 1H, CH2),
1.98 (br s, 3H, NMe), 2.19 (br s, 3H, NMe), 2.28 (br s, 3H,
NMe), 2.81 (br s, 3H, NMe). 19F NMR (CDCl3, 282.2 MHz, 23
2J FF ) 270 Hz, J FF ) 13 Hz, J FF ) 8 Hz, J FF ) 15 Hz,
3
3
4
2J FPt ) 246 Hz, R-CF), -79.7 (dd, J FF ) 13.5 Hz, J FF ) 15
4
4
4
Hz, J FPt ) 19 Hz, CF3).
3
(TMEDA)P t(n -C3F 7)(CH3) (9a ). To a solution of (TMEDA)-
Pt(n-C3F7)(CH3)2I (0.105 g, 0.165 mmol) in moist acetone (15
mL) was added Et3N (2 mL, excess) and the pale yellow
solution stirred for 16 h. The solvent was removed in vacuo
and the resultant solid treated with Et2O. The white precipi-
°C): δ -113.0 (br s, â-CF2), -79.8 (t, J FPt ) 11 Hz, CF3). 19F
2
NMR (toluene-d8, 470.4 MHz, -60 °C): δ -114.6 (d, J FF
)
2
283 Hz, â-CF), -110.9 (d, J FF ) 283 Hz, â-CF), -94.2 (d,
2J FF ) 262 Hz, R-CF), -78.9 (m, CF3), -64.4 (d, J FF ) 262
2
Hz, R-CF).

3810 Organometallics, Vol. 20, No. 17, 2001
Hughes et al.
3
2
[(TMEDA)P t(n -C3F 7)(OH2)]O3SCF 3 (17). Addition of CF3-
SO3H (0.020 mL, 0.226 mmol) to a solution of (TMEDA)Pt(n-
C3F7)(CH3) (0.100 g, 0.202 mmol) in CH2Cl2 (15 mL) gave a
pale yellow solution, which was stirred for 2 h. Removal of
volatiles in vacuo gave a white solid, which was washed with
CHCl3. Yield: 0.050 g, 38%. Anal. Calcd for C10H18F1oN2O4-
PtS: C, 18.55; H, 2.80; N, 4.30. Found: C, 18.73; H, 2.72; N,
4.31. 1H NMR (acetone-d6, 300 MHz, 23 °C): δ 2.83 (s, 6H,
NMe), 3.04 (s, 6H, NMe), 3.02-3.15 (m, 4H, CH2). 19F NMR
121.4 MHz, -40 °C): δ 34.5 (td, J PF ) 13.0 Hz, J PP ) 5.3
1
3
1
Hz, J PPt ) 4409 Hz), 46.8 (br t, J PF ) 29 Hz, J PPt ) 1969
Hz).
(DP P E)P t(n -C3F 7)I (22). Meth od A. To a solution of
(DPPE)Pt(n-C3F7)OTf (0.123 g, 0.132 mmol) in moist CH2Cl2
was added a solution of NaI (0.19 g, excess) in H2O (5 mL).
The resultant colorless emulsion was stirred for 16 h. Separa-
tion of the organic layer followed by drying over MgSO4 and
filtration through Celite gave a colorless solution. Removal of
solvent in vacuo gave a white solid, which was washed with
EtOH and hexanes. Yield: 0.114 g, 97%. Anal. Calcd for
3
(acetone-d6, 282.2 MHz, 23 °C): δ -119.8 (s, J FPt ) 48 Hz,
2
3
â-CF2), -99.8 (s, J FPt ) 260 Hz, R-CF2), -80.6 (t, J FF ) 11
Hz, CF3), -79.3 (s, SO3CF3).
C
29H24F7IP2Pt: C, 39.16; H, 2.70. Found: C, 38.92; H, 2.74.
1H NMR (CDCl3, 300 MHz, 23 °C): δ 2.03-2.15 (m, 4H, CH2),
7.45-7.57 (m, 12H, Ph), 7.72-7.79 (m, 8H, Ph). 19F NMR
(CDCl3, 282.2 MHz, 23 °C): δ -114.8 (s, 3J FPt ) 56 Hz, â-CF2),
-80.2 (t, 4J FF ) 9.5 Hz, CF3), -79.4 (m, 2J FPt ) 366 Hz, R-CF2).
(TMEDA)P t(n -C3F 7)H (18). Addition of EtOH (10 mL) to
a mixture of (TMEDA)Pt(n-C3F7)I (0.092 g, 0.152 mmol) and
NaBH4 (0.2 g, excess) and stirring for 1 h gave a colorless
suspension. Removal of volatiles followed by extraction into
toluene and filtration through Celite gave a colorless solution,
which was reduced in vacuo to a white solid. Yield: 0.070 g,
96%. Anal. Calcd for C9H17F7N2Pt: C, 22.46; H, 3.56; N, 5.82.
31P{1H} NMR (CDCl3, 121.4 MHz, 23 °C): δ 40.3 (t, J PF ) 29
3
1
3
2
Hz, J PPt ) 1785 Hz), 42.5 (td, J PF ) 28 Hz, J PP ) 4.5 Hz,
1J PPt ) 3806 Hz).
Meth od B. A suspension of ((DPPE)Pt(n-C3F7)(CH3) (0.100
g, 0.129 mmol) and I2 (0.033 g, 0.130 mmol) in hexanes (15
mL) was stirred for 16 h. The resultant white precipitate was
collected by filtration and then recrystallized from CH2Cl2/
EtOH. Yield: 0.088 g, 77%.
1
Found: C, 22.24; H, 3.43; N, 5.76. H NMR (C6D6, 300 MHz,
1
23 °C): δ -20.96 (br s, 1H, J HPt ) 1734 Hz, PtH), 1.36-1.48
3
(m, 4H, CH2), 2.12 (s, 6H, J HPt ) 32.1 Hz, NMe), 2.29 (s, 6H,
3J HPt ) 18.3 Hz, NMe). 19F NMR (C6D6, 282.2 MHz, 23 °C): δ
4
3
-119.9 (d, J FH ) 4 Hz, J FPt ) 233 Hz, â-CF2), -88.2 (q,
(DP P E)P t(n -C3F 7)H (23). To a solution of (DPPE)Pt(n-
C3F7)I (0.114 g, 0.128 mmol) in CH2Cl2 (15 mL) was added a
solution of NaBH4 (0.15 g, excess) in EtOH (5 mL) and the
resultant suspension stirred for 30 min. The solid residue was
extracted into Et2O and filtered through Celite. Removal of
solvent in vacuo gave a white solid, which was washed with
EtOH and hexanes. Yield: 0.092 g, 94%. Anal. Calcd for
4J FF ) 10.5 Hz, J FPt ) 402 Hz, R-CF2), -78.3 (t, J FF ) 10.5
2
4
Hz, J FPt ) 60 Hz, CF3). 19F NMR (CD2Cl2, 470.4 MHz, -75
4
°C): δ -118.7 (d, 2J FF ) 279 Hz, 3J FPt ) 235 Hz, â-CF), -117.8
2
3
2
(d, J FF ) 279 Hz, J FPt ) 238 Hz, â-CF), -88.5 (br d, J FF
)
2
2
276 Hz, J FPt ) 328 Hz, R-CF), -87.1 (br d, J FF ) 276 Hz,
2J FPt ) 384 Hz, R-CF), -77.2 (t, J FF ) 10 Hz, CF3). Crystals
4
for the structure determination were grown from Et2O/hep-
tane as colorless prisms.
C
29H25F7P2Pt: C, 45.62; H, 3.27. Found: C, 45.35; H, 3.26. 1H
NMR (CDCl3, 300 MHz, 23 °C): δ -2.81 (ddtt, 2J HP ) 189 Hz,
2J HP ) 15 Hz, J HF ) 8.0 Hz, J HF ) 7.0 Hz, 1H, J PtH ) 1209
Hz, PtH), 2.20-2.40 (m, 4H, CH2), 7.38-7.45 (m, 12H, Ph),
7.60-7.70 (m, 4H, Ph), 7.75-85 (m, 4H, Ph). 19F NMR (CDCl3,
3
4
1
(DP P E)P t(n -C3F 7)(CH3) (19). A solution of (TMEDA)Pt-
(n-C3F7)Me (1.00 g, 2.02 mmol) and DPPE (0.808 g, 2.03 mmol)
in toluene (10 mL) was heated under reflux for 3 h. The
resultant colorless solution was reduced in vacuo to a white
solid, which was collected on a glass frit and washed with
EtOH and then hexanes. Yield: 1.47 g, 93%. Anal. Calcd for
4
4
282.2 MHz, 23 °C): δ -121.1 (dd, J FP ) 7 Hz, J FH ) 7 Hz,
3J FPt ) 152 Hz, â-CF2), -83.3 (ddqd, J FP ) 33 Hz, J FP ) 32
3
3
4
3
2
Hz, J FF ) 10 Hz, J FH ) 8 Hz, J FPt ) 379 Hz, R-CF2), -79.2
(t, J FF ) 10 Hz, J FPt ) 40 Hz, CF3). 31P{1H} NMR (CDCl3,
4
4
C
30H27F7P2Pt: C, 46.34; H, 3.50. Found: C, 46.20; H, 3.45. 1H
3
1
121.4 MHz, 23 °C): δ 49.0 (t, J PF ) 33 Hz, J PtP ) 2043 Hz),
50.7 (tt, 3J PF ) 32 Hz, 4J PF ) 7 Hz, 1J PtP ) 1812 Hz). The latter
resonance has the large coupling to the hydride resonance and
is consequently that of the phosphorus trans to H.
3
NMR (CDCl3, 300 MHz, 23 °C): δ 0.63 (t, J HP ) 7.2 Hz, 3H,
2J HPt ) 84 Hz, PtMe), 2.11-2.24 (m, 4H, CH2), 7.37-7.51 (m,
12H, Ph), 7.62-7.69 (m, 8H, Ph). 19F NMR (CDCl3, 282.2 MHz,
3
2
23 °C): δ -119.5 (s, J FPt ) 84 Hz, â-CF2), -88.1 (m, J FPt
)
Cr ysta llogr a p h ic Str u ctu r a l Deter m in a tion s. Crystal,
data collection, and refinement parameters are collected in
Table 1. The systematic absences in the diffraction data are
uniquely consistent for the reported space groups. Compound
23 crystallized with two independent molecules in the asym-
metric unit. The structures were solved using direct methods,
completed by subsequent difference Fourier syntheses, and
refined by full-matrix least-squares procedures. DIFABS
absorption corrections were applied to all structures. All non-
hydrogen atoms were refined with anisotropic displacement
coefficients, and hydrogen atoms were treated as idealized
contributions.
4
4
366 Hz, R-CF2), -80.1 (t, J FF ) 10 Hz, J FPt ) 27 Hz, CF3).
31P{1H} NMR (CDCl3, 121.4 MHz, 23 °C): δ 45.6 (t, J PF
)
3
28.8 Hz, 1J PPt ) 2101 Hz), 49.1 (t, 3J PF ) 33.4 Hz, 1J PPt ) 1779
Hz).
(DP P E)P t(n -C3F 7)OTf (20). Addition of CF3SO3H (0.046 g,
0.307 mmol) to a solution of (DPPE)Pt(n-C3F7)(CH3) (0.200 g,
0.257 mmol) in CH2Cl2 (15 mL) and stirring for 16 h gave a
pale yellow solution, which was reduced in vacuo to a yellow
oil. Dissolution in CH2Cl2 and filtration through Celite, fol-
lowed by addition of toluene and removal of the CH2Cl2 in
vacuo, gave a white precipitate, which was collected on a glass
frit and washed with toluene. Yield: 0.225 g, 94%. Crystals
suitable for X-ray diffraction analysis were grown by slow
evaporation of a CH2Cl2 solution. (dppe)Pt(C3F7)OTf (20): Anal.
Calcd for C30H24F10P2O3PtS: C, 39.53; H, 2.65. Found: C,
39.60; H, 2.61. 1H NMR (CD2Cl2, 300 MHz, 23 °C): δ 2.04-
2.55 (m, 4H, CH2), 7.50-7.68 (m, 12H, Ph), 7.74-7.85 (m, 8H,
Ph). 19F NMR (CD2Cl2, 282.2 MHz, -20 °C): δ -118.4 (s,
â-CF2), -91.8 (s, 2J FPt ) 325 Hz, R-CF2), -78.9 (s, CF3), -76.5
(br, s, SO3CF3). 31P{1H} NMR (CD2Cl2, 121.4 MHz, -30 °C):
All software and sources of the scattering factors are
contained in the SHELXTL (5.10) program library.
Ack n ow led gm en t. R.P.H. is grateful to the Na-
tional Science Foundation and to the Petroleum Re-
search Fund, administered by the American Chemical
Society for generous financial support.
Su p p or tin g In for m a tion Ava ila ble: Atomic fractional
coordinates, bond distances and angles, and anisotropic ther-
mal parameters for complexes 6a , 9a , 9b, 10, 13, 18, 19, 20,
and 23 are available free of charge via the Internet at
http://pubs.acs.org.
1
3
1
δ 36.1 (m, J PPt ) 4651 Hz), 46.0 (br t, J PF ) 29 Hz, J PPt
)
1963 Hz). [(dppe)Pt(C3F7)(OH2)]OTf (21): 1H NMR (CD2Cl2, 300
MHz, -20 °C): δ 2.12-2.21 (m, 2H, CH2), 2.35-2.45 (m, 2H,
CH2), 7.51-7.77 (m, 20H, Ph). 19F NMR (CD2Cl2, 282.2 MHz,
-20 °C): δ -118.9 (s, â-CF2), -96.1 (s, 2J FPt ) 310 Hz, R-CF2),
-78.6 (br, s, CF3), -77.6 (s, O3SCF3). 31P{1H} NMR (CD2Cl2,
OM010424H