A study of the reaction of perfluoroalkyl Grignard reagents with phosphoryl chloride and phenylphosphonic dichloride

Article abstract of DOI:10.1039/c2dt31371e

Perfluoroalkyl Grignard reagents react with phosphoryl halides at -78 °C to room temperature to selectively produce bis(perfluoroalkyl)phosphonyl halides, which after aqueous work up, give bis(perfluoroalkyl)phosphinic acids in high overall yields. Reaction of perfluoroalkyl Grignards with phenylphosphonic dichloride gives high yields of bis(perfluoroalkyl)phenyl phosphine oxides which are readily hydrolysed to perfluoroalkyl(phenyl) phosphinic acids.

Full text of DOI:10.1039/c2dt31371e

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PAPER
A study of the reaction of perfluoroalkyl Grignard reagents with phosphoryl
chloride and phenylphosphonic dichloride
Adil I. Hoseina and Andrew J. M. Caffyn*a,b
Received 26th June 2012, Accepted 14th September 2012
DOI: 10.1039/c2dt31371e
Perfluoroalkyl Grignard reagents react with phosphoryl halides at −78 °C to room temperature to
selectively produce bis(perfluoroalkyl)phosphonyl halides, which after aqueous work up, give
bis(perfluoroalkyl)phosphinic acids in high overall yields. Reaction of perfluoroalkyl Grignards with
phenylphosphonic dichloride gives high yields of bis(perfluoroalkyl)phenyl phosphine oxides which are
readily hydrolysed to perfluoroalkyl(phenyl)phosphinic acids.
Introduction
The reaction of phosphoryl chloride, OvPCl3, with convention-
al alkyl and aryl Grignards has been well studied.1–4 The reac-
tion is generally employed to produce tertiary phosphine oxides.
By using slow, and reversed order of addition (i.e. OvPCl3
present in excess), disubstituted phosphinic5 acids can be syn-
thesised in moderate yield after hydrolytic work up (Scheme 1).6
We report here a study of the reaction of perfluoroalkyl Grignard
reagents with phosphoryl chlorides. We have found that bis
(perfluoroalkyl)phosphinic halides are produced selectively,
which can be hydrolysed in situ to give high yields of the corres-
Scheme 1 General reaction of Grignard reagents with phosphoryl
ponding bis(perfluoroalkyl)phosphinic acids. In an extension of
chloride.
the procedure, use of phenylphosphonic dichloride leads to the
production of bis(perfluoroalkyl)phenyl phosphine oxides and
perfluoroalkyl(phenyl)phosphinic acids. The relatively non-
at δ −79.9 and a doublet at δ −121.3 ppm. We assigned these
hazardous nature and the inexpensive reagents makes the pro-
peaks to the presence of (C2F5)2P(O)Cl [lit: 31P NMR δ 21.4
cedure an attractive alternative to previously reported syntheses
2
3
(pentet, JP–F = 97.06 Hz): 19F NMR δ −79.34 (td, JP–F
=
of bis(perfluoroalkyl)phosphinic acids7–16 and perfluoroalkyl-
3
3.05 Hz, JF–F = 0.54 Hz, CF3); −121.0 (m, CF2)].11 The reaction
proceeds equally as well with the bromo-Grignard C2F5MgBr or
indeed when OvPBr3 is used in place of OvPCl3. 31P and 19F
NMR monitoring of the reaction of C2F5MgBr and OvPCl3
indicates formation of two species. (C2F5)2P(O)Cl is observed as
before. The second species exhibited a pentet in the 31P NMR
spectrum centred at δ 15.0 ppm (2JP–F = 93 Hz). In the 19F
NMR spectrum a broad singlet at δ −79.2 and a doublet at δ
−120.3 ppm were observed. We have tentatively assigned this
species as (C2F5)2P(O)Br on the basis that this was the only
species observed spectroscopically when C2F5MgBr was reacted
with OvPBr3. Chlorine-bromine exchange is a known process
at phosphoryl and phosphonyl centres.20–23 Quenching of
(C2F5)2P(O)X (X = Cl, Br) with water cleanly generated
(C2F5)2P(O)OH11 which, after treatment with an equivalent of
aniline, was conveniently isolated as the corresponding anilinium
salt, [PhNH3][(C2F5)2PO2]. The free acid could be quantitatively
regenerated by passing an aqueous solution through a column of
Amberlite (IR120) cation exchange resin column in the H+ form.
Extension of this synthetic methodology to extended chain
(aryl)phosphinic acids.17–19
Results
The phosphinic acids (Rf)2P(O)OH (Rf = C2F5, n-C4F9, n-
C6F13, n-C8F17) were prepared in 60–80% yield by reaction of
RfMgX (X = Cl, Br) with phosphoryl chloride at −78 °C in
ether for 3 hours followed by quenching with water (Scheme 2).
31P and 19F NMR spectra of the acids agree with the literature
values.11,13
31P NMR monitoring of the reaction of C2F5MgCl with
OvPCl3 indicates the presence of a pentet at δ 21.8 ppm (2JP–F
= 96 Hz), while the 19F NMR spectrum showed a broad singlet
aDepartment of Chemistry, The University of the West Indies,
St. Augustine, Trinidad and Tobago
bSchool of Biology, Chemistry & Health Science, Manchester
Metropolitan University, John Dalton Building, Chester St., Manchester,
UK, M1 5GD. E-mail: a.caffyn@mmu.ac.uk; Tel: +44 (0)161 2471443
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Scheme 2 Reaction of perfluoroalkyl Grignard reagents with phosphoryl chloride.
Scheme 4 Hydrolysis of bis(perfluoroalkyl)phenyl phosphine oxides.
Scheme 3 Reaction of perfluoroalkyl Grignard reagents with phenyl
phosphonic dichloride.
hydrolyse more slowly than the short chain analogues. The per-
fluoroalkyl(phenyl)phosphinic acids were crystallised as their
toluidinium salts, after treatment with an equivalent of p-tolu-
idine. By contrast with these results, Röschenthaler and co-
workers report selective monosubstitution in the case of the
reaction of ortho-bromodifluoromethyl arylphosphonic dichlor-
ides with C2F5Li.19 It should be noted, however, that disubstitu-
tion cannot be ruled out, since under the 10% HCl work up
employed, hydrolysis of any initially formed bis(perfluoroethyl)-
aryl phosphine oxide to the isolated product, perfluoroethyl(aryl)-
phosphinic acid, is likely. The procedure described herein
constitutes a convenient “one pot” route to mixed perfluoroalkyl
(phenyl) phosphinic acids. This method of synthesis is a
convenient alternative to Yagupol’skii’s original synthesis which
involves hydrolysis of dihaloarylbis(heptafluoropropyl)-
phosphoranes.17
We also tested the reactivity of the perfluoroalkyl Grignard
reagents towards other phosphorus(V) reagents. After low temp-
erature addition of n-C4F9MgBr to OvP(OPh)3 or SvPCl3,
however, only unreacted triphenylphosphate or thiophosphoryl
chloride respectively were observed in the 31P NMR spectrum
after warming to room temperature. By comparison triarylphos-
phates react with alkyl and aryl Grignards in a similar manner to
phosphoryl chloride.32 Thiophosphoryl chloride reacts with aryl
Grignards to form triarylphosphine oxides.33 With low molecular
weight primary alkyl Grignards, tetraalkylbiphosphine disulfides
are generally formed instead.34–36 The various factors influen-
cing tertiary phosphine sulphide vs. biphosphine disulphide for-
mation have been previously discussed.4,37 The fact that these
reactions were reported at or above room temperature may
explain why no reaction was observed in the case of the tempera-
ture sensitive perfluoroalkyl Grignards.
perfluoroalkyl iodides led to the isolation of anilinium salts of
the corresponding phosphinic acids, [PhNH3][(Rf)2PO2] (Rf =
n-C4F9, n-C6F13, n-C8F17) in 60–80% overall yields.
No evidence of perfluoroalkylphosphonic dichloride mono-
substituted products was observed [e.g. RfP(O)X2 (X = Cl, Br)].
This is in contrast to the predominant monosubstitution observed
upon reaction of phosphorus(III) halides with perfluoroalkyl
Grignard reagents.15 Unlike with the conventional Grignard
chemistry, trisubstitution of OvPCl3, to produce tertiary phos-
phine oxides, was not observed.1–4 It should be noted, however,
that this trisubstitution with conventional Grignard reagents has
generally been observed at, or above, room temperature. Presum-
ably substitution of a third perfluoroalkyl group is slow at low
temperature and thus perfluoroalkyl Grignard decomposition sets
in rapidly upon warming above −20 °C.24–27 It should be noted
that the procedure cannot be extended to the use of CF3MgBr,
due to the known instability of this reagent above −78 °C.28–30
We also studied the reaction of perfluoroalkyl Grignard
reagents with phenylphosphonic dichloride, to examine whether
perfluoroalkyl(phenyl)phosphonic halides or bis(perfluoroalkyl)-
phenyl phosphine oxides would be produced. We observed
exclusive disubstitution. No evidence of perfluoroalkyl(phenyl)-
phosphonic halide monosubstitution product was detected by 31
P
and 19F NMR. Thus, as shown in Scheme 3, phosphine oxides
could be isolated in 60–80% yields by reaction of a slight excess
of RfMgBr with OvPPhCl2. In the 19F NMR spectrum of
OvPPh(C2F5)2, an AB system is observed for the different
fluorine atoms of the CF2 groups, as has been observed and dis-
cussed for OvPH(C2F5)2.31 OvPPh(C2F5)2 and OvPPh(n-
C4F9)2 are liquids which decomposed during attempted distilla-
tion and were therefore purified by flash chromatography.
OvPPh(n-C6F13)2 and OvPPh(n-C8F17)2, however, can be
crystallised as white crystalline solids. Yagupol’skii and co-
workers17 have synthesised bis(heptafluoropropyl)phenyl phos-
phine oxide. It was reported that this phosphine oxide is easily
hydrolysed to give heptafluoropropyl(phenyl) phosphinic acid.
We substantiated that the other phosphine oxides could be hydro-
lysed in similar fashion (Scheme 4). Although, we note that the
longer chain perfluoroalkyl derivatives, n-C6F13 and n-C8F17,
Conclusions
While examining the reaction of phosphoryl chloride and phe-
nylphosphonic dichloride with perfluoroalkyl Grignard reagents,
we have developed a convenient “one pot” laboratory scale
synthesis of bis(perfluoroalkyl)- and perfluoroalkyl(phenyl)-
Dalton Trans.
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phosphinic acids, and bis(perfluoroalkyl)phenyl phosphine
oxides, in moderate to high yield.
−122.3 (d, CF2P, 4F), −126.1 (br s, CF2, 4F). 1H NMR (d6-
DMSO): δ 9.78 (br s, NH3, 3H), 7.49 (m, 2H), 7.40 (m, 1H),
7.33 (m, 2H). Anal. Calcd for C14F18H8NO2P: C, 28.25; H,
1.35; N, 2.35. Found: C, 28.73; H, 1.31; N, 2.30.
Experimental
Synthesis of [PhNH3][(n-C6F13)2PO2]. n-C6F13I, (3.0 g,
6.7 mmol), EtMgBr, (6.7 mmol in 50 mL of ether), OvPCl3
(0.49 g, 3.2 mmol), and aniline (0.80 g, 8.6 mmol in 30 mL
pentane) were used in an analogous procedure to that described
above to produce [PhNH3][(n-C6F13)2PO2], (1.95 g, 81%; mp
176.1–177.0 °C), as a white solid. 31P NMR (d6-DMSO): δ 0.4
General
Perfluoroalkyliodides, n-CnF2n+1I (n = 2,4,6,8) were purchased
from Apollo Scientific Ltd. OvPCl3, OvPBr3 and OvPPhCl2
were purchased from Aldrich and used as received. Etheral solu-
tions of EtMgBr and EtMgCl were prepared and standardised
before use. All organic solvents used were distilled and
degassed. Ether was dried and distilled from sodium/benzophe-
none and stored over 4 Å molecular sieves. Reactions were
carried out in 100 mL Schlenk tubes and under an inert atmos-
phere of dry argon using standard Schlenk line techniques. 31P,
19F, 13C and 1H NMR spectra were recorded by an Bruker
AVANCE 400 MHz FT NMR spectrometer with 85% H3PO4,
CCl3F and (CH3)4Si as external references respectively. Elemen-
tal analyses were performed by Medac Ltd. The yields given on
all isolated products are based on the perfluoroalkyliodide
reagent unless otherwise stated.
2
(pentet, JPF = 64.5 Hz). 19F NMR (d6-DMSO): δ −80.8 (s,
CF3, 6F), −120.5 (br s, CF2, 4F), −122 (d, CF2P, 4F), −122.1
(br s, CF2, 4F), −123.2 (br s, CF2, 4F), −126.4 (br s, CF2, 4F).
1H NMR (d6-DMSO): δ 9.73 (br s, NH3, 3H), 7.48 (m, 2H),
7.38 (m, 1H), 7.31 (m, 2H). Anal. Calcd for C18F26H8NO2P: C,
27.19; H, 1.01; N, 1.76. Found: C, 27.47; H, 0.92; N, 1.87.
Synthesis of [PhNH3][(n-C8F17)2PO2]. n-C8F17I, (4.00 g,
7.3 mmol in 5 mL of ether), EtMgBr, (8 mmol in 45 mL of
ether), OvPCl3 (0.53 g, 3.5 mmol) and aniline (0.5 g, 5.4 mmol
in 30 mL pentane) were used in an analogous procedure to that
described above to produce [PhNH3][(n-C8F17)2PO2] (2.10 g,
60%; mp 143.4–144.1 °C) as a white solid. 31P NMR (d6-
Synthesis of [PhNH3][(C2F5)2PO2]. C2F5MgBr was produced
in a Schlenk tube by stirring C2F5I (9.8 g, 40 mmol in 43 mL of
ether) and EtMgBr, (50 mmol in 17 mL of ether), together under
argon at −78 °C for 1 hour as described in the literature.38,39
OvPCl3, (2.9 g, 19 mmol), was added dropwise and the reac-
tion mixture was allowed to stir at −78 °C for 3 hours and then
slowly warmed to room temperature. Water, (10 mL), was slowly
added at 0 °C. The ether layer was separated and washed with
water (3 × 25 mL). The combined water washings were back-
washed with ether (3 × 10 mL). All the ether layers were com-
bined and evaporated to give crude (C2F5)2P(O)OH as a yellow-
brown oil. Aniline (4.0 g, 43 mmol in 50 mL CH2Cl2) was
added dropwise with stirring giving an immediate yellow pre-
cipitate. The stirring was continued until the oil was consumed.
The mass was filtered, washed with CH2Cl2 followed by
pentane, recrystallised from acetone–chloroform (3 : 17, v/v) and
2
DMSO): δ 0.6 (pentet, JPF = 65 Hz). 19F NMR (d6-DMSO): δ
−81.0 (s, CF3, 6F), −120.6 (br s, CF2, 4F), −122.1 (br s, CF2,
4F), −122.4 (br s, CF2, 8F), −122.5 (d, CF2P, 4F), −123.4 (br s,
1
CF2, 4F), −126.5 (br s, CF2, 4F). H NMR (d6-DMSO): δ 9.74
(br s, NH3, 3H); 7.47 (m, 2H); 7.36 (m, 1H); 7.30 (m, 2H).
Anal. Calcd for C22F34H8NO2P: C, 26.55; H, 0.81; N, 1.41.
Found: C, 26.70; H, 0.64; N, 1.51.
Conversion of [PhNH3][(C2F5)2PO2] to free acid. Analytically
pure [PhNH3][(C2F5)2PO2] (0.400 g, 1.012 mmol) was dissolved
in deionised water and passed through an Amberlite IR120A
cation exchange column (H+ form), eluting with water. The com-
bined fractions of eluent where made up to 5.0 mL in a volu-
metric flask and the concentration determined as 0.20 M (∼95%
yield) by 31P NMR spectroscopy (1 scan) using OP(OPh)3 as
external standard. The 31P and 19F NMR spectra agreed with the
literature values for (C2F5)2P(O)OH11 and are essentially indis-
dried in vacuo to yield white crystalline [PhNH3][(C2F5)2PO2]
(4.4 g, 60%). 31P NMR (d6-DMSO): δ −1.3 (pentet, JPF
=
2
1
tinguishable from that of [PhNH3][(C2F5)2PO2]. The H and 13C
65.4 Hz). 19F NMR (d6-DMSO): δ −80.5 (s, CF3, 6F), −125.6
(d, CF2, 4F). 1H NMR (d6-DMSO): δ 9.75 (br s, NH3, 3H), 7.49
(m, 2H), 7.41 (m, 1H), 7.34 (m, 2H). Anal. Calcd for
C10F10H8NO2P: C, 30.40; H, 2.04; N, 3.54. Found: C, 30.88; H,
2.04; N, 3.37.
NMR spectra showed no aromatic peaks. 13C NMR (d6-DMSO):
1
2
2
119.9 (qtd, JCF = 286 Hz, JCF = 32 Hz, JCP = 16 Hz, CF3),
112.6 (tdq, 1JCF = 280 Hz, 1JCP = 125 Hz, 2JCF = 36 Hz, CF2).
Isolation of (n-C8F17)2PO2H·H2O. n-C8F17I, (3.80 g,
7.0 mmol in 5 mL of ether), EtMgBr, (8 mmol in 40 mL of
ether) were stirred at −78 °C for 1 hour under argon. OvPCl3
(0.51 g, 3.3 mmol) was added dropwise and the mixture stirred
at −78 °C for 3 hours and then slowly warmed to room tempera-
ture. The mixture was then first quenched with water (10 mL),
washed with more water (3 × 10 mL) and then dried over 4 Å
molecular sieves for 24 hours. Slow evaporation of the ether led
to precipitation of (n-C8F17)2PO2H.H2O as a white solid (2.03 g,
63%; mp 303 °C dec). 31P NMR spectrum (d6-DMSO): δ 4.50
Synthesis of [PhNH3][(n-C4F9)2PO2]. n-C4F9I, (4.1 g,
12 mmol), EtMgBr, (12 mmol in 60 mL of ether) and OvPCl3
(0.87 g, 5 mmol), were used in an analogous procedure to that
described above to produce crude (n-C4F9)2P(O)OH. An aniline
solution (0.8 g, 8.6 mmol in 30 mL pentane) was added drop-
wise. The resulting mixture was left to stir overnight after which
a yellow precipitate was obtained. The precipitate was filtered
and washed several times with 3 mL aliquots of CH2Cl2, until a
white powder was obtained. This was then recrystallized from
acetone/chloroform and dried in vacuo at room temperature to
yield [PhNH3][(n-C4F9)2PO2] as a white solid. (1.90 g, 64%).
2
(pentet, JP–CF2 = 68 Hz), [lit:13 δ 4.39 (pentet, 2JP–F = 67 Hz)].
19F NMR spectrum (d6-DMSO): δ −81.2 (s, CF3, 3F), δ −120.5
(br s, CF2, 2F), −122.3 (m, 3 × CF2, 6F & CF2P, 2F), −123.3
(br s, CF2, 2F), −126.9 (br s, CF2, 2F), [lit:13 δ −80.8 (CF3),
2
31P NMR (d6-DMSO): δ −0.2 (pentet, JPF = 65.6 Hz). 19F
NMR (d6-DMSO): δ −81.0 (s, CF3, 6F), −121.5 (br s, CF2, 4F),
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2
−119.7 (CF2), −121.5 (d, JP–F = 67 Hz, CF2P), −121.7 (3 ×
(m, 2H); 7.85 (m, 1H), 7.71 (m, 2H). Anal. Calcd for
C22F34H5OP: C, 27.46; H, 0.52. Found: C, 27.54; H, 0.49.
CF2), −122.7 (CF2), −126.1 (CF2)]. Anal. Calcd for
C16H3F34O3P: C, 20.89; H, 0.33. Found: C, 20.60; H, 0.17.
Synthesis of [p-MeC6H4NH3][(C2F5)PhPO2]. OvPPh(C2F5)2
(3.00 g, 8.3 mmol), was stirred with a solution of p-toluidine
(1.10 g, 10.3 mmol in 20 mL acetone–water, 19 : 1, v/v) for
10 min. Removal of volatiles gave a yellow solid which was
recrystallized from acetone–chloroform (3 : 17, v/v) to yield [p-
MeC6H4NH3][(C2F5)PhPO2], (3.60 g, 92%), as a white crystal-
line solid. 31P NMR (d6-DMSO): δ 14.6 (tt, 2JPF = 68.4 Hz, 3JPH
= 12 Hz). 19F NMR (d6-DMSO): δ −80.5 (s, CF3, 3F), −122.0
(d, CF2, 2F). 1H NMR (d6-DMSO): δ 9.50 (br s, NH3, 3H), 7.67
(m, 2H), 7.45 (m, 3H), 6.85 (m, 4H), 2.13 (s, CH3, 3H).
Synthesis of OvPPh(C2F5)2. C2F5MgBr was generated
in situ, by reacting C2F5I, (5.50 g, 22 mmol in 52 mL of ether),
with EtMgBr, (22 mmol in 8 mL of ether), for 1 hour at −78 °C
in a 100 mL Schlenk tube. OvPPhCl2 (2.1 g, 10.7 mmol), was
added and the reaction was stirred for 3 hours and then slowly
warmed to room temperature. The top layer of the product
mixture was separated and the ether was removed by vacuum to
leave behind a brown residue. The residue was then subjected to
flash column chromatography using neutral silica gel and eluting
with a mixture of toluene and dichloromethane (2 : 1, v/v). The
solvents of the collected eluent were then pumped off at 80 °C,
0.3 mbar for 24 hours leaving behind a light yellow viscous oil,
OvPPh(C2F5)2 (4.40 g, 60%). 31P NMR (C6D6): δ 20.7 (br tt,
Synthesis of [p-MeC6H4NH3][(n-C4F9)PhPO2]. OvPPh-
(n-C4F9)2 (3.00 g, 5.4 mmol), water (20 mL) and p-toluidine
(0.75 g, 7 mmol in 20 mL acetone–water, 19 : 1, v/v), were used
in an analogous procedure to that described above to give white,
crystalline [p-MeC6H4NH3][(n-C4F9)PhPO2] (3.00 g, 96%). 31P
2
2JPFa ≈ JPFb = 70 Hz). 19F NMR (C6D6): δ −80.0 (s, CF3, 6F),
2
1
−120.6 (dd, JFaFb = 340Hz, CFa, 2F) −123.2 (dd, CFb, 2F). H
NMR (C6D6): δ 7.75 (m, 2H), 7.03 (m, 1H), 6.94 (m, 2H).
NMR (d6-DMSO): δ 12.6 (tt, 2JPF = 68.4 Hz, 3JPH = 12 Hz). 19
F
NMR (d6-DMSO): δ −80.5 (br s, CF3, 3F), −120.2 (br s, CF2,
1
2F), −122.0 (br d, CF2P, 2F), −124.5 (br s, CF2, 2F). H NMR
Synthesis of OvPPh(n-C4F9)2. n-C4F9I (4.80 g, 13.9 mmol),
EtMgBr (15 mmol in 50 mL ether) and OvPPhCl2 (1.30 g,
6.7 mmol) were used in an analogous procedure to that described
above to give OvPPh(n-C4F9)2 as a slightly impure light yellow
viscous oil (5.50 g, 71%). 31P NMR (C6D6): δ 21.7 (br pentet,
2JPF = 73 Hz). 19F NMR (C6D6): δ −83.5 (s, CF3, 6F), −120.0
(m, CF2P, 4F), −121.1 (br s, CF2, 4F), −128.0 (br s, CF2, 4F).
1H NMR (C6D6): δ 7.72 (m, 2H), 7.18 (m, 1H), 7.07 (m, 2H).
(d6-DMSO): δ 9.50 (br s, NH3, 3H), 7.70 (m, 2H), 7.40 (m, 3H),
6.89 (m, 4H), 2.10 (s, 3H, CH3). Anal. Calcd for
C17F9H15NO2P: C, 43.70; H, 3.24; N, 3.00. Found: C, 43.18; H,
3.27; N, 3.04.
Synthesis of [p-MeC6H4NH3][(n-C6F13)PhPO2]. OvPPh-
(n-C6F13)2 (2.00 g, 2.62 mmol) was stirred with a solution of
p-toluidine (0.40 g, 3.73 mmol in 30 mL acetone–water, 19 : 1,
v/v) at room temperature until the solid was consumed
(∼2 hours). Acetone was removed by using a rotary evaporator
to leave an initial yellow-brown solid which was washed with
chloroform then recrystallized from acetone–chloroform (1 : 3,
v/v) and dried in vacuo at room temperature to yield [p-
MeC6H4NH3][(n-C6F13)PhPO2] as a white fluffy solid, (1.40 g,
Synthesis of OvPPh(n-C6F13)2. n-C6F13I, (10.32 g,
23.13 mmol), EtMgBr, (24 mmol in 60 mL of ether) and
OvPPhCl2 (2.05 g, 10.51 mmol) were used in an analogous
procedure to that described above, except that only dichloro-
methane was used as the elution solvent in the flash column
chromatography stage. The collected eluant was then pumped off
at 80 °C, 0.3 mbar for 24 hours leaving behind a white powder
which was recrystallized from toluene to give OvPPh(n-C6F13)2
as a white crystalline solid (6.20 g, 77%; mp 77.5–77.9 °C). 31P
2
3
95%). 31P NMR (d6-DMSO): δ 10.1 (tt, JPF = 63.3 Hz, JPH
=
11 Hz). 19F NMR (d6-DMSO): δ −80.9 (br s, CF3, 3F), −120.2
(br s, CF2, 2F), −122.2, (d, CF2P), −122.4, (br s, CF2), −123.2
(br s, CF2 2F), −126.4, (s, CF2, 2F). H NMR (d6-DMSO): δ
9.95 (br s, 3H, NH3 ), 7.73 (m, 2H), 7.47 (m, 1H), 7.40 (m,
1
2
NMR (CDCl3): δ 23.2 (pentet, JPF = 74.5 Hz). 19F NMR
+
(CDCl3): δ −82.7 (t, CF3, 6F), −118.3 (m, CF2P, 4F), −119.7
(br s, CF2, 4F), −123.0 (br s, CF2, 4F), −124.2 (br s, CF2, 4F),
2H), 7.22 (m, 4H), 2.29 (s, 3H). Anal. Calcd for
C19F13H15NO2P: C, 40.23; H, 2.67; N, 2.47. Found: C, 39.66;
H, 2.59; N, 2.27.
1
−127.8 (br s, CF2, 4F). H NMR (CDCl3): δ 8.03 (m, 2H), 7.84
(m, 1H), 7.68 (m, 2H). Anal. Calcd for C18F26H5OP: C, 28.37;
H, 0.66. Found: C, 28.34; H, 0.69.
Synthesis of [p-MeC6H4NH3][(n-C8F17)PhPO2]. OvPPh(n-
C8F17)2 (2.0 g, 2.39 mmol) was stirred with a solution of p-tolui-
dine (0.40 g, 3.73 mmol in 30 mL acetone–water, 19 : 1, v/v) at
room temperature until the solid was consumed (∼2 hours).
Acetone was removed using a rotary evaporator to leave an
initial yellow-brown solid which was washed with chloroform
then recrystallized from acetone–chloroform (1 : 3, v/v) and
dried in vacuo at room temperature to yield [p-MeC6H4NH3][(n-
Synthesis of OvPPh(n-C8F17)2. n-C8F17I, (5.10 g, 9.3 mmol
in 5 mL of ether), EtMgBr, (12 mmol in 50 mL of ether) and
OvPPhCl2 (0.87 g, 4.4 mmol) were used in an analogous pro-
cedure to that described above, except that only dichloromethane
was used as the elution solvent in the flash column chromato-
graphy stage. The collected eluent was then pumped off at
80 °C, 0.3 mbar for 24 hours leaving a white powder which was
recrystallized from toluene to give OvPPh(n-C8F17)2 as a white
crystalline solid (3 g, 70%; mp 92.7–93.4 °C). 31P NMR
C8F17)PhPO2] as a white fluffy solid, (1.20 g, 92% yield; mp
2
189.8–190.9 °C). 31P NMR (d6-DMSO): δ 11.9 (tt, JPF
=
71.1 Hz, JPH = 10 Hz). 19F NMR (d6-DMSO): δ −82.0 (s,
CF3), −120.5 (br s, CF2, 2F), −122.5 (br s, CF2, 2F), −122.8 (br
s, CF2, 4F), −123.2 (d, CF2P, 2F), −123.6 (br s, CF2, 2F),
−127.1 (br s, CF2, 2F). 1H NMR (d6-DMSO): δ 9.70 (br s, NH3,
3H), 7.71 (m, 2H), 7.40 (m, 1H), 7.35 (m, 2H), 7.23 (m, 2H),
3
2
(CDCl3): δ 23.2 (pentet, JPF = 74.9 Hz). 19F NMR (CDCl3): δ
−81.2 (s, CF3, 6F), −117.2 (m, CF2P, 4F), −118.7 (br s, CF2,
4F), −121.9 (br s, CF2, 4F), −122.3 (br s, CF2, 8F), −123.2 (br
1
s, CF2, 4F), −126.6 (br s, CF2, 4F). H NMR (CDCl3): δ 8.04
Dalton Trans.
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Dalton Trans.