Synthesis and characterisation of trisarylphosphine selenides: Further insight into the effect of fluoroalkylation on the electronic properties of trisarylphosphines

Article abstract of DOI:10.1016/j.poly.2006.11.025

Variations in the magnitude of the ¹J_SeP coupling constants for a range of phosphorus(V) selenides allow the efficiency of different spacer groups at insulating the phosphorus centre in triarylphosphines from highly electron-withdrawing perfluoroalkyl groups to be established.

Full text of DOI:10.1016/j.poly.2006.11.025

Polyhedron 26 (2007) 1505–1513
www.elsevier.com/locate/poly
Synthesis and characterisation of trisarylphosphine selenides:
Further insight into the effect of fluoroalkylation on the
electronic properties of trisarylphosphines
*
Dave J. Adams, James A. Bennett, Daniel Duncan, Eric G. Hope , Jonathan Hopewell,
Alison M. Stuart, Andrew J. West
Department of Chemistry, University of Leicester, Leicester, LE1 7RH, UK
Received 11 August 2006; accepted 17 November 2006
Available online 23 November 2006
Abstract
1
Variations in the magnitude of the JSeP coupling constants for a range of phosphorus(V) selenides allow the efficiency of different
spacer groups at insulating the phosphorus centre in triarylphosphines from highly electron-withdrawing perfluoroalkyl groups to be
established.
ꢀ 2006 Elsevier Ltd. All rights reserved.
Keywords: Phosphine; Fluorous; NMR; Selenide
1. Introduction
of ponytails present [6]. Secondly, the high electron-with-
drawing ability of the perfluorocarbon groups has led many
to attempt to minimise this effect on the phosphorus centre
of the triarylphosphine by the introduction of so-called
‘spacer groups’, including the aromatic ring itself, [7] as well
as additional alkyl groups such as CH2CH2 [8] and the
incorporation of a heteroatom such as oxygen [9] or silicon
[10]. In this regard, theoretical calculations, on trialkylphos-
phines, suggest that five methylene spacer units are neces-
sary to completely eliminate the electronic influence of the
perfluoroalkyl units [11]. The effect of the perfluoroalkyl
groups on the electronic properties of the donor phosphine
has been probed experimentally, but work is limited to vari-
ations in mCO in a few analogues of Vaska’s complex [12] and
1JPtP coupling constants for some cis-[PtCl2L2] complexes
[13,14]. Systematic comparisons have not been possible for
a variety of reasons, including variations in approach/
procedure by different groups, the absence of specific com-
plexes or questions over the significance of steric/electronic
factors, particularly for bulky ligands. An alternative,
valuable, method for probing the effect of substitution on
Since the introduction of the fluorous biphase approach
to catalyst/product separation in homogeneous catalysis
´
´
by Horvath and Rabai, [1] phosphines, as modifying ligands
for metal catalysts, have received substantially more interest
than any other ligand class, with applications including
hydrogenation, [2] hydrosilylation [3] and palladium-cataly-
sed cross-coupling reactions [4]. Throughout, preferential
solubility of the ligand in the perfluorocarbon (or fluorous)
solvent is achieved by derivatising the catalyst with so-called
perfluorocarbon ‘ponytails’, such that the catalyst in the flu-
orous solvent can be recycled by a simple phase separation
following the reaction. To-date, work has focussed on two
key ligand properties: Firstly, since preferential solubility
in the perfluorocarbon solvents is critical, the solubilising
power of different groups has been evaluated, [5] and there
have been a number of attempts at maximising the number
*
Corresponding author. Tel.: + 44 116 252 2108; fax: + 44 116 252
3789.
1
the aryl rings of triarylphosphines is the j JSePj coupling
E-mail address: egh1@le.ac.uk (E.G. Hope).
0277-5387/$ - see front matter ꢀ 2006 Elsevier Ltd. All rights reserved.
doi:10.1016/j.poly.2006.11.025

1506
D.J. Adams et al. / Polyhedron 26 (2007) 1505–1513
constant [15] of the corresponding phosphorus(V) selenide,
[16,17] prepared by the oxidation of the phosphine with
elemental selenium, where phosphorus(V) selenides incor-
porating electron-withdrawing groups exhibit larger cou-
pling constants that those for phosphorus(V) selenides
incorporating electron-donating groups. Here, we report
data for a comprehensive series of phosphorus(V) selenides,
which offer a clearer insight into the effect of perfluoroalkyl
groups on the electronic properties of phosphines used in
fluorous catalysis.
2.1.1. 4-(Trifluoromethylphenyl)diphenylphosphine (1a)
M.p. = 53–54 ꢁC (Lit. 51–53 ꢁC) [26]. m/z (FAB) 330
1
3
(M+). H NMR (CDCl3) 7.50 (2H, d, JHH 10.0, ArH),
3
7.30 (2H, d, JHH 10.0, ArH), 7.28 (10H, m, ArH).
19F{1H} NMR (CDCl3) ꢀ63.20 (s). 31P{1H} NMR
(CDCl3) ꢀ5.4 (s).
2.1.2. 4-(Heptadecafluoro-n-octylphenyl)diphenylphosphine
(1c)
M.p. = 89–91 ꢁC. Anal. Calc. for C26H14F17P: C, 45.88;
H, 2.06. Found: C, 45.89; H, 1.95%. m/z (FAB) 680 (M+).
1H NMR (CDCl3) 7.45 (2H, d, 3JHH 8.0, ArH), 7.31 (12H,
m, ArH). 19F{1H} NMR (CDCl3) ꢀ80.76 (3F, t, 4JFF 10.0,
2. Experimental
4
CF3), ꢀ110.78 (2F, t, JFF 14.4, a-CF2), ꢀ121.21 (2F, m,
Proton, 19F and 31P NMR spectroscopies were carried
out on a Bruker ARX250 spectrometer at 250.13, 235.34
and 101.26 MHz or a Bruker DPX300 spectrometer at
300.14, 282.41 and 121.50 MHz, respectively, and were
referenced to external SiMe4 (1H), external CFCl3 (19F)
and to external H3PO4 (31P) using the high frequency
positive convention. Abbreviations for NMR spectral
multiplicities are as follows: s = singlet, d = doublet,
t = triplet, q = quartet, m = multiplet. Elemental analyses
were performed by the Elemental Analysis Service at the
University of North London. Mass spectra were recorded
on a Kratos Concept 1H mass spectrometer.
CF2), ꢀ121.84 (6F, m, 3 · CF2), ꢀ122.68 (2F, m, CF2),
ꢀ126.12 (2F, m, CF2). 31P{1H} NMR (CDCl3) ꢀ5.4 (s).
2.1.3. 4-(1H,1H,2H,2H-tridecafluoro-n-
octyldimethylsilylphenyl)diphenylphosphine (1f)
M.p. = 186 ꢁC dec. Anal. Calc. for C28H24F13PSi: C,
50.37; H, 3.60. Found: C, 50.51; H, 3.58%. m/z (FAB)
1
3
667 (MH+). H NMR (CDCl3) 7.31 (2H, dd, JPH 10.9,
3JHH 8.0, ArH-2,6), 7.20 (12H, m, ArH), 1.87 (2H, m,
CH2), 0.85 (2H, m, CH2Si), 0.18 (6H, s, CH3). 19F{1H}
4
NMR (CDCl3) ꢀ81.30 (3F, t, JFF 10.1, CF3), ꢀ116.45
4
(2F, t, JFF 14.0, a-CF2), ꢀ122.48 (2F, m, CF2), ꢀ123.40
P(4-C6H4R)3 (R = H, F, Cl, Me, OMe and NMe2) and
BINAP were commercial samples and used as received,
whilst cis-[PtCl2(MeCN)2] was prepared by the literature
route [18].
(2F, m, CF2), ꢀ123.66 (2F, m, CF2), ꢀ126.67 (2F, m,
CF2). 31P{1H} NMR (CDCl3) ꢀ5.7 (s).
2.1.4. Tris-(4-heptadecafluoro-n-octylphenyl)phosphine
(3c)
2.1. General procedure for the preparation of phosphines
M.p. = 92 ꢁC (Lit. 92–95 ꢁC) [27]. m/z (FAB) 1516
3
(M+). 1H NMR (CDCl3) 7.53 (6H, d, JHH 7.9, ArH-
3
3
n-BuLi (2.0 mmol, 1.6 M solution in hexane) was added
dropwise over 1 h to a solution of the required bromoben-
zene (2.0 mmol) in diethyl ether at ꢀ78 ꢁC. This solution
was then stirred at ꢀ78 ꢁC for 3 h. The requisite chloro-
phosphine (2.0 mmol for diphenylchlorophosphines,
1.0 mmol for dichlorophenylphosphines or 0.66 mmol for
PCl3) was then added dropwise in a solution of diethyl
ether over 1 h and the solution allowed to warm to room
temperature overnight. The solution was then washed well
with water, the organic layer separated, dried and the sol-
vent removed in vacuo. The resulting phosphine was puri-
fied by column chromatography using petroleum ether as
the eluent. Uniquely, 1f was prepared by a modification
of the literature route for 3f, [6b] by the reaction of the
chlorosilane with the lithiate formed from the reaction of
Ph2P(C6H4-4-Br) with BuLi at low temperature in diethyle-
ther. Many of the phosphines prepared in this work have
been described previously (1b, [7]; 2b, [7]; 3a, [15]; 3b, [7];
3d, [8b]; 3e, [11]; 3f, [6b]; 3g, [9a]; 3h, [9b]; 3j, [19]; 3k,
[20]; 3l, [21]; 4b, [14]; 5b, [14]; 6b, [22]; 7a, [23]; 7b, [24];
7c, [24]; 8a, [24]; 8b, [24]; 9a, [22,23]; 10a, [24]; 10b, [24];
11b, [25]; 11d, [25]), and here we just report data for new
ligands and additional data for established species where
appropriate.
3,5), 7.35 (6H, t, JHH 7.7, JPH 7.7, ArH-2,6). 19F{1H}
4
NMR (CDCl3) ꢀ80.76 (9F, t, JFF 8.9, CF3), ꢀ110.99
4
(6F, t, JFF 14.0, a-CF2), ꢀ121.17 (6F, m, CF2), ꢀ121.72
(18F, m, 3 · CF2), ꢀ122.67 (6F, m, CF2), ꢀ126.08 (6F,
m, CF2). 31P{1H} NMR (CDCl3) ꢀ6.2 (s).
2.1.5. 3-(Heptadecafluoro-n-octylphenyl)diphenylphosphine
(4c)
Oil. Anal. Calc. for C26H14F17P: C, 45.88; H, 2.06.
Found: C, 45.72; H, 2.00%. m/z (FAB) 680 (M+). 1H
NMR (CDCl3) 7.46 (2H, m, ArH), 7.37 (2H, m, ArH),
7.22 (10H, m, ArH). 19F{1H} NMR (CDCl3) ꢀ80.78 (3F,
4
4
t, JFF 10.0, CF3), ꢀ110.89 (2F, t, JFF 14.2, a-CF2),
ꢀ121.31 (2F, m, CF2), ꢀ122.04 (6F, m, 3 · CF2),
ꢀ122.78 (2F, m, CF2), ꢀ126.20 (2F, m, CF2). 31P{1H}
NMR (CDCl3) ꢀ5.1 (s).
2.1.6. Tris-(3-heptadecafluoro-n-octylphenyl)phosphine
(5c)
M.p. = 77–78 ꢁC (Lit. 84–86 ꢁC) [27]. m/z (FAB) 1516
1
(M+). H NMR (CDCl3) 7.59–7.46 (9H, m, ArH), 7.35
3
(3H, d, JHH 6.3, ArH). 19F{1H} NMR (CDCl3) ꢀ80.92
4
4
(9F, t, JFF 9.4, CF3), ꢀ111.47 (6F, t, JFF 14.0, a-CF2),
ꢀ121.45 (6F, m, CF2), ꢀ122.10 (18F, m, 3 · CF2),

Table 1
NMR spectral data for phosphorus(V) selenidesa
Phosphine
M.p.
(ꢁC)
Elemental
analysisb
m/zc
1H
19F{1H}
31P{1H}
3
3
1
1a
88–91
39–40
88–89
C, 55.63
409 (M+)
7.76 (2H, dd, JPH 12.4, JHH 8.4, ArH-2,6), 7.61 (6H, m,
ꢀ63.09 (3F, s, CF3)
35.1 (s, JSeP 741),
1
(55.88); H,
3.36 (3.43)
C, 43.64
(43.77); H,
1.97 (2.13)
C, 41.38
ArH), 7.40 (6H, m, ArH)
35.5 (s, JSeP 774)d
3
3
4
4
1
1b
1c
661 (MH+) 7.79 (2H, dd, JPH 12.9, JHH 8.5, ArH-2,6), 7.65 (6H, m,
ꢀ81.32 (3F, t, JFF 9.9, CF3), ꢀ111.55 (2F, t, JFF
13.7, a-CF2), ꢀ121.93 (4F, m, 2 · CF2), ꢀ123.25 (2F,
m, CF2), ꢀ126.62 (2F, m, CF2)
34.9 (s, JSeP 743),
ArH), 7.42 (6H, m, ArH)
34.7 (s,1JSeP 774)d
3
3
4
4
1
759 (M+)
7.78 (2H, dd, JPH 12.8, JHH 8.3, H-2,6), 7.67 (6H, m,
ꢀ80.75 (3F, t, JFF 10.0, CF3), ꢀ111.05 (2F, t, JFF
14.2, a-CF2), ꢀ121.15 (2F, m, CF2), ꢀ121.47 (2F, m,
CF2), ꢀ121.82 (4F, m, 2 · CF2), ꢀ122.66 (2F, m, CF2),
ꢀ126.10 (2F, m, CF2)
35.1 (s, JSeP 742),
1
(41.11); H,
1.92 (1.84)
ArH), 7.46 (6H, m, ArH)
35.5 (s, JSeP 775)d
4
4
1
1f
99–101
Oil
C, 45.10
747 (MH+) 7.64–7.54 (6H, m, ArH), 7.45–7.31 (8H, m, ArH), 1.88 (2H, ꢀ81.27 (3F, t, JFF 9.0, CF3), ꢀ116.71 (2F, t, JFF
35.0 (s, JSeP 730),
1
(45.16); H,
3.13 (3.23)
C, 37.08
(36.89); H,
1.25 (1.33)
C, 33.48
(33.38); H 0.71 (MH+)
(0.93)
C, 31.67
(31.62); H,
0.78 (0.75)
m, CH2CF2), 0.87 (2H, m, CH2Si), 0.20 (6H, s, CH3)
12.0, a-CF2), ꢀ122.49 (2F, m, CF2), ꢀ123.66 (2F, m,
CF2), ꢀ124.04 (2F, m, CF2), ꢀ126.68 (2F, m, CF2)
36.8 (s, JSeP 766)d
3
3
4
4
1
2b
3b
3c
979 (MH+) 7.78 (4H, dd, JPH 12.9, JHH 8.5, ArH-2,6), 7.64 (5H, m,
ꢀ81.38 (6F, t, JFF 9.6, CF3), ꢀ111.72 (4F, t, JFF
34.5 (s, JSeP 756),
1
ArH), 7.44 (4H, m, ArH)
13.58, a-CF2), ꢀ121.95 (8F, m, 2 · CF2), ꢀ123.28 (4F, 34.7 (s, JSeP 782)d
m, CF2), ꢀ126.64 (4F, m, CF2)
3
3
4
4
1
76–77
1297
7.79 (6H, dd, JPH 13.0, JHH 8.3, ArH-2,6), 7.64 (6H, dd, ꢀ81.40 (9F, t, JFF 9.8, CF3), ꢀ111.74 (6F, t, JFF
34.0 (s, JSeP 769),
3JHH 8.3, JPH 2.9, ArH-3,5)
13.6, a-CF2), ꢀ121.99 (12F, m, 2 · CF2), ꢀ123.29 (6F, 33.9 (s, JSeP 792)d
4
1
m, CF2), ꢀ126.67 (6F, m, CF2)
3
3
4
4
1
126–
127
1596
(MH+)
7.80 (6H, dd, JPH 13.2, JHH 8.5, ArH-2,6), 7.62 (6H, dd, ꢀ81.19 (9F, t, JFF 9.8, CF3), ꢀ111.56 (6F, t, JFF
35.8 (s, JSeP 793)d
3JHH 8.5, JPH 2.1, ArH-3,5)
13.3, a-CF2), ꢀ121.57 (6F, m, CF2), ꢀ121.92 (6F, m,
CF2), ꢀ122.24 (12F, m, 2 · CF2), ꢀ123.07 (6F, m,
CF2), ꢀ126.50 (6F, m, CF2)
4
3
3
4
4
1
3d
3e
3g
3h
3l
71–72
C, 36.60
1380
(MH+)
7.59 (6H, dd, JPH 13.3, JHH 8.2, ArH-2,6), 7.22 (6H, dd, ꢀ80.82 (9F, t, JFF 9.8, CF3), ꢀ114.51 (6F, t, JFF
33.8 (s, JSeP 733),
1
(36.57); H,
1.89 (1.74)
C, 38.14
(38.03); H,
2.03 (2.11)
C, 32.84
3JHH 8.2, 4JPH 2.5, ArH-3,5), 2.88 (6H, m, CH2), 2.32 (6H, 14.5, a-CF2), ꢀ121.86 (6F, m, CF2), ꢀ123.42 (6F, m,
34.2 (s, JSeP 767)d
m, CH2)
CF2), ꢀ123.47 (6F, m, CF2), ꢀ126.12 (6F, m, CF2)
4 4
3
3
1
118–
120
1423
(MH+)
7.58 (6H, dd, JPH 13.3, JHH 8.2, ArH-2,6), 7.19 (6H, m,
ArH-3,5), 2.67 (6H, m, CH2), 1.97 (12H, m, 2 · CH2)
ꢀ80.77 (9F, t, JFF 10.0, CF3), ꢀ114.10 (6F, t, JFF
14.8, a-CF2), ꢀ121.89 (6F, m, CF2), ꢀ122.85 (6F, m,
33.8 (s, JSeP 725),
1
34.2 (s, JSeP 764)d
CF2), ꢀ123.35 (6F, m, CF2), ꢀ126.08 (6F, m, CF2)
3
3
4
1
112–
114
1537
(MH+)
7.59 (6H, dd, JPH 12.9, JHH 9.1, ArH-2,6), 6.92 (6H, dd, ꢀ81.36 (9F, t, JFF 10.1, CF3), ꢀ119.84 (6F, m, a-
3JHH 9.1 4JPH 2.1 ArH-3,5), 4.42 (6H, t, 3JHF 12.60, OCH2) CF2), ꢀ122.53 (12F, m, 2 · CF2), ꢀ122.79 (6F, m,
CF2), ꢀ123.58 (6F, m, CF2), ꢀ126.73 (6F, m, CF2)
31.1 (s, JSeP 729),
1
(32.73); H,
1.00 (1.17)
33.3 (s, JSeP 759)d
3
3
4
4
1
80–81
(dec)
1770
(MH+)
7.56 (6H, dd, JPH 12.9, JHH 8.8, ArH-2,6), 6.85 (6H, dd, ꢀ81.25 (9F, t, JFF 9.0, CF3), ꢀ114.83 (6F, t, JFF
31.4 (s, JSeP 715),
3JHH 8.8, JPH 2.0, ArH-3,5), 4.00 (6H, m, OCH2), 2.18
15.0, a-CF2), ꢀ122.69 (18F, m, 3 · CF2), ꢀ123.58 (6F, 33.2 (s, JSeP 754)d
4
1
(6H, m, CH2), 2.09 (6H, m, CH2)
m, CF2), ꢀ124.46 (6F, m, CF2), ꢀ126.58 (6F, m, CF2)
1
121–
123
C, 37.25
579 (MH+) 7.52–7.43 (12H, m, ArH)
33.7 (s, JSeP 748),
1
(37.44); H,
1.98 (2.08)
C, 55.69
(55.75); H,
3.50 (3.42)
35.4 (s, JSeP 778)d
3
3
1
4a
4b
Oil
Oil
411 (MH+) 7.94 (1H, d, JPH 13.4, ArH-2), 7.81 (1H, dd, JPH 12.9
ꢀ62.75 (s, CF3)
35.3 (s, JSeP 742)
3JHH 7.6, ArH-6), 7.64 (5H, m, ArH), 7.39 (7H, m, ArH)
661 (MH+) 7.92 (1H, dd, 3JPH 13.0, 3JHH 7.6, ArH-6), 7.82 (1H, d, 3JPH ꢀ80.86 (3F, t, JFF 9.5, CF3), ꢀ111.01 (2F, t, JFF
35.3 (s, JSeP 744),
4
4
1
1
13.5, ArH-2), 7.67–7.42 (12H, m, ArH)
14.1, a-CF2), ꢀ121.38 (2F, m, CF2), ꢀ121.91 (2F, m,
CF2), ꢀ122.80 (2F, m, CF2), ꢀ126.15 (2F, m, CF2)
35.7 (s, JSeP 774)d
(continued on next page)

Table 1 (continued)
Phosphine
M.p.
(ꢁC)
Elemental
analysisb
m/zc
1H
19F{1H}
31P{1H}
1
4c
0Oil
760 (MH+) 7.93 (1H, dd, 3JPH 12.9, 3JHH 7.5, ArH-6), 7.83 (1H, d, 3JPH ꢀ80.83 (3F, t, 4JFF 9.1, CF3), ꢀ111.28 (2F, t, 4JFF 14.0, 35.3 (s, JSeP 744)
13.8, ArH-2), 7.70–7.35 (12H, m, ArH)
a-CF2), ꢀ121.20 (2F, m, CF2), ꢀ121.73 (2F, m, CF2),
ꢀ121.89 (2F, m, CF2), ꢀ122.54 (2F, m, CF2), ꢀ122.68
(2F, m, CF2), ꢀ126.14 (2F, m, CF2)
3
3
1
5b
5c
6a
6b
157–
158
C, 33.14
1297
(MH+)
8.09 (3H, dd, JPH 13.7, JHH 7.6, ArH-2), 7.69 (9H, m,
ArH)
ꢀ81.45 (9F, t, 4JFF 9.3, CF3), ꢀ112.07 (6F, t, 4JFF 14.0, 34.7 (s, JSeP 772),
1
(33.38); H,
0.98 (0.93)
C, 31.82
(31.62); H,
0.67 (0.75)
C, 55.86
(55.75); H,
3.51 (3.42)
C, 43.59
(43.77); H,
2.13 (2.13)
a-CF2), ꢀ122.13 (6F, m, CF2), ꢀ122.48 (6F, m, CF2), 35.8 (s, JSeP 796)d
ꢀ123.57 (6F, m, CF2), ꢀ126.86 (6F, m, CF2)
3
3
1
126–
127
1596 (M+)
8.16 (3H, dd, JPH 13.8, JHH 7.2, ArH-2), 7.61 (9H, m,
ꢀ80.75 (9F, t, 4JFF 8.5, CF3), ꢀ111.08 (6F, t, 4JFF 14.1, 34.6 (s, JSeP 773)
ArH)
a-CF2), ꢀ121.15 (6F, m, CF2), ꢀ122.00 (18F, m,
3 · CF2), ꢀ122.68 (6F, m, CF2) ꢀ126.10 (6F, m, CF2)
4
4
1
97–100
411
(MH+)e
7.75 (4H, m, ArH), 7.55 (2H, m, ArH), 7.40 (8H, m, ArH) ꢀ53.52 (d, JPF 3, CF3)
38.0 (q, JPF 3, JSeP
752)
4
4
108–
109
7.70 (4H, m, ArH), 7.55 (2H, m, ArH), 7.38 (8H, m, ArH) ꢀ80.81 (3F, t, JFF 11.3, CF3), ꢀ99.69 (2F, dt, JPF
40.4 (t, 4JPF 10, 1JSeP
10.0, 4JFF 15.3, a-CF2), ꢀ117.62 (2F, m, CF2), ꢀ121.41 757), 39.9 (t, 4JPF 10,
(2F, m, CF2), ꢀ122.88 (2F, m, CF2), ꢀ126.17 (2F, m, 1JSeP 791)
CF2)
3
1
7a
7b
7c
Oil
Oil
Oil
C, 50.69
477 (M+)
977 (M+)
8.09 (2H, d, JPH 12.6, ArH-2,6), 7.91 (1H, s, ArH-4), 7.63 ꢀ62.84 (s, CF3)
35.0 (s, JSeP 755),
1
(50.42); H,
2.60 (2.73)
C, 36.72
(36.89); H,
1.30 (1.33)
C, 34.44
(4H, m, ArH), 7.44 (6H, m, ArH)
35.8 (s, JSeP 784)d
3
1
8.08 (2H, d, JPH 12.7, ArH-2,6), 7.82 (1H, s, ArH-4), 7.63 ꢀ80.82 (6F, t, 4JFF 9.7, CF3), ꢀ111.08 (4F, t, 4JFF 14.0, 35.2 (s, JSeP 758),
1
(4H, m, ArH), 7.59 (6H, m, ArH)
a-CF2), ꢀ121.30 (4F, m, CF2), ꢀ121.89 (4F, m, CF2), 35.8 (s, JSeP 785)d
ꢀ122.73 (4F, m, CF2), ꢀ126.11 (4F, m, CF2)
3
4
4
1
8.08 (2H, d, JPH 12.9, ArH-2,6), 7.83 (1H, s, ArH-4), 7.53 ꢀ81.78 (6F, t, JFF 10.4, CF3), ꢀ111.21 (4F, t, JFF
35.2 (s, JSeP 758)
(34.66); H,
1.00 (1.10)
(10H, m, ArH)
14.2, a-CF2), ꢀ121.11 (8F, m, 2 · CF2), ꢀ121.90 (8F,
m, 2 · CF2), ꢀ122.67 (4F, m, CF2), ꢀ126.06 (4F, m,
CF2)
3
1
8a
8b
Oil
Oil
C, 43.15
613 (M+)
8.09 (4H, d, JPH 13.0, ArH-2,6), 7.99 (2H, s, ArH-4), 7.54 ꢀ63.04 (s, CF3)
34.6 (s, JSeP 779),
1
(43.14); H,
1.82 (1.80)
C, 31.54
(31.27); H,
0.59 (0.68)
(5H, m, ArH)
35.2 (s, JSeP 801)d
3
4
4
1
1613 (M+)
8.03 (4H, d, JPH 12.8, ArH-2,6), 7.89 (2H, s, ArH-4), 7.49 ꢀ81.09 (12F, t, JFF 9.8, CF3), ꢀ111.74 (8F, t, JFF
34.7 (s, JSeP 785),
1
(5H, m, ArH)
14.2, a-CF2), ꢀ121.50 (8F, m, CF2), ꢀ122.12 (8F, m,
CF2), ꢀ122.96 (8F, m, CF2), ꢀ126.40 (8F, m, CF2),
ꢀ63.50 (s, CF3)
35.3 (s, JSeP 806)d
3
1
9a16
10a
8.11 (6H, d, JPH 13.1 ArH-2,6), 8.09 (3H, s, ArH-4),
34.3 (s, JSeP 803),
1
34.3 (s, JSeP 817)d
3
4
1
Oil
Oil
C, 34.59
(34.53); H,
0.90 (0.99)
8.08 (2H, d, JPH 13.0, ArH-20,60), 7.99 (1H, s, ArH-4’),
ꢀ62.93 (6F, s, CF3), ꢀ80.78 (6F, t, JFF 9.8, CF3),
34.2 (s, JSeP 780),
4
1
7.80 (4H, m, C6H4), 7.70 (4H, m, C6H4)
ꢀ111.29 (4F, t, JFF 14.3, a-CF2), ꢀ121.33 (4F, m,
34.8 (s, JSeP 801)d
CF2), ꢀ121.70 (4F, m, CF2), ꢀ122.82 (4F, m, CF2),
ꢀ126.08 (4F, m, CF2)
3
4
4
1
10b
C, 31.48
(31.27); H,
0.55 (0.68)
1613 (M+)
8.01 (2H, d, JPH 13.0, ArH-20,60), 7.87 (1H, s, ArH-4’),
ꢀ81.21 (12F, t, JFF 10.7, CF3), ꢀ111.45 (4F, t, JFF
34.0 (s, JSeP 785),
3
3
4
1
7.78 (4H, dd, JPH 13.2, JHH 8.3, ArH-2,6), 7.66 (4H, dd, 14.2, a-CF2), ꢀ111.72 (4F, t, JFF 14.2, a-CF2),
34.3 (s, JSeP 803)d
3JHH 8.3, JPH 2.2, ArH-3,5)
ꢀ121.56 (8F, m, CF2), ꢀ122.14 (8F, m, CF2), ꢀ123.0
(8F, m, CF2), ꢀ126.42 (8F, m, CF2)
4

D.J. Adams et al. / Polyhedron 26 (2007) 1505–1513
1509
ꢀ122.90 (6F, m, CF2) ꢀ126.29 (6F, m, CF2). 31P{1H}
NMR (CDCl3) ꢀ6.9 (s).
2.2. General procedure for the preparation of phosphorus(V)
selenides
The phosphine (0.20 g) was dissolved in chloroform
(10 ml) and selenium powder added (0.30 g, 3.8 mmol).
The mixture was heated to 70 ꢁC overnight. After cooling,
the excess selenium was removed by filtration through a
cotton wool plug and the solvent removed in vacuo to
give the phosphorus(V) selenide in a 64–89% yield. A few
of the phosphorus(V) selenides used in this study have been
reported previously; tris(4-N,N-dimethylaminophenyl)
phosphine selenide, [28] tris(4-methoxyphenyl)phosphine
selenide, tris(4-methylphenyl)phosphine selenide, trisphe-
nylphosphine selenide, tris(4-fluorophenyl)phosphine sele-
nide, tris(4-trifluoromethylphenyl)phosphine selenide, tris
(3-trifluoromethylphenyl)phosphine selenide and tris(3,5-
trifluoromethylphenyl)phosphine selenide, [15] and tris(4-
chlorophenyl)phosphine [29]. Table 1 summarises all the
analytical and NMR spectroscopic data for the new phos-
phorus(V) selenides prepared in this work.
2.3. General procedure for the preparation of [PtCl2L2]
complexes
The phosphine (0.1 mmol) and [PtCl2(CH3CN)2]
(0.05 mmol) were dissolved in dichloromethane (10 ml)
and heated to reflux for 2 h. After cooling, the solvent
was removed and the resulting solid washed well with
petroleum ether to give a pale yellow solid in 84–91% yield.
2.3.1. cis- and trans-[PtCl2{Ph2P(C6H4-4-CF3)}2]
Anal. Calc. for C38H28Cl2F6P2Pt: C, 49.30; H, 3.03.
1
Found: C, 49.15; H, 3.03%. m/z (FAB) 891 (MꢀCl)+. H
NMR (CDCl3) 7.96 (8H, m, ArH), 7.36 (12H, m, ArH),
7.19 (8H, m, ArH). 19F{1H} NMR (CDCl3) ꢀ63.00 (s,
trans), ꢀ63.10 (s, cis). 31P{1H} NMR (CDCl3) 20.5 (s, 1JPtP
1
2656, trans), 14.7 (s, JPtP 3653, cis).
2.3.2. cis- and trans-[PtCl2{Ph2P(C6H4-4-C8F17)}2]
m/z (FAB) 1591 (MꢀCl)+. 1H NMR (CDCl3) 7.70 (4H,
3
3
d, JHH 7.8, ArH-3,5), 7.53 (4H, t, JHH = 3JPH 7.8, ArH-
2,6), 7.34 (16H, m, PhH), 7.19 (4H, m, PhH). 19F{1H}
4
NMR (CDCl3) ꢀ80.73 (6F, t, JFF 9.8, CF3), ꢀ111.09
4
(4F, t, JFF 13.7, a-CF2), ꢀ121.17 (4F, m, CF2), ꢀ121.54
(4F, m, CF2), ꢀ121.84 (8F, m, 2 · CF2), ꢀ122.64 (4F, m,
CF2), ꢀ126.06 (2F, m, CF2). 31P{1H} NMR (CDCl3)
1
1
20.5 (s, JPtP 2664, trans), 14.5 (s, JPtP 3653, cis).
2.3.3. cis- and trans-[PtCl2{Ph2P(C6H4-4-
SiMe2C2H4C6F13)}2]
Anal. Calc. for C56H48Cl2F26P2Pt: C, 42.08; H, 3.01.
Found: C, 42.06; H, 2.89%. m/z (FAB) 1563 (MꢀCl)+.
1H NMR (CDCl3) 7.63–7.08 (28H, m, ArH), 1.89 (4H,
m, CH2CF2), 0.88 (4H, m, CH2Si), 0.23 (12H, s, CH3).

1510
D.J. Adams et al. / Polyhedron 26 (2007) 1505–1513
4
1
1
19F{1H} NMR (CDCl3) ꢀ81.30 (6F, t, JFF 9.9, CF3),
NMR (CDCl3) 21.2 (s, JPtP 2663, trans), 16.1 (s, JPtP
3650, cis).
4
ꢀ116.68 (4F, t, JFF 14.1, a-CF2), ꢀ123.06 (4F, m, CF2),
ꢀ123.63 (4F, m, CF2), ꢀ124.02 (4F, m, CF2), ꢀ126.67
(4F, m, CF2). 31P{1H} NMR (CDCl3) 19.9 (s, JPtP 2632,
2.3.7. cis- and trans-[PtCl2{P(C6H4-4-C8F17)3}2]
Anal. Calc. for C84H24Cl2F102P2Pt: C, 30.58; H, 0.73.
Found: C, 30.50; H, 0.64%. m/z (MALDI-TOF) 3227
1
1
trans), 13.8 (s, JPtP 3673, cis).
3
2.3.4. cis- and trans-[PtCl2{P(C6H4-4-
CH2CH2CH2C6F13)3}2]
(Mꢀ2Cl)+. 1H NMR (C6D6/C6F6) 7.98 (6H, dd, JHH
3
3
3
8.2, JPH 5.5, ArH-2,6), 7.79 (6H, dd, JHH 8.2, JPH 8.5,
3
Anal. Calc. for C90H60Cl2F78P2Pt: C, 36.61; H, 2.03.
Found: C, 36.70; H, 1.96%. m/z (FAB) 2915 (MꢀCl)+.
ArH-2,6), 7.72 (12H, d, JHH 8.2, ArH-3,5). 19F{1H}
4
NMR (C6D6/C6F6) ꢀ83.48 (18F, t, JFF 10.0, CF3),
1H NMR (CDCl3) 7.34 (12H, dd, JPH 11.2, JHH 8.2,
ArH-2,6), 6.90 (12H, m, ArH-3,5), 2.60 (12H, m, CH2),
1.87 (24H, m, CH2). 19F{1H} NMR (CDCl3) ꢀ81.10
ꢀ113.30 (6F, t, JFF 14.6, a-CF2), ꢀ113.43 (6F, t, JFF
15.5, a-CF2), ꢀ122.92 (12F, m, CF2), ꢀ123.33 (24F, m,
2 · CF2), ꢀ123.49 (12F, m, CF2), ꢀ124.34 (12F, m, CF2),
ꢀ128.04 (12F, m, CF2). 31P{1H} NMR (C6D6/C6F6) 20.5
3
3
4
4
4
4
(18F, t, JFF 9.9, CF3), ꢀ114.31 (12F, t, JFF 12.3, a-
CF2), ꢀ122.09 (12F, m, CF2), ꢀ122.68 (12F, m, CF2),
ꢀ123.06 (12F, m, CF2), ꢀ126.42 (12F, m, CF2). 31P{1H}
1
1
(s, JPtP 2741, trans), 15.2 (s, JPtP 3570, cis).
1
1
NMR (CDCl3) 18.6 (s, JPtP 2614, trans), 12.8 (s, JPtP
3679, cis).
2.3.8. cis- and trans-[PtCl2{Ph2P(C6H3-3,5-[CF3]2)}2]
Anal. Calc. for C40H26Cl2F12P2Pt: C, 45.24; H, 2.45.
Found: C, 45.03; H, 2.38%. m/z (FAB) 1027 (MꢀCl)+.
3
2.3.5. cis-[PtCl2{Ph2P(C6H4-3-CF3)}2]
Anal. Calc. for C38H28Cl2F6P2Pt: C, 49.24; H, 3.02.
Found: C, 49.18; H, 2.96%. m/z (FAB) H NMR (CDCl3)
1H NMR (CDCl3) 7.66 (2H, s, ArH-4), 7.60 (2H, d, JPH
3
11.6, ArH-2,6), 7.58 (2H, d, JPH 11.1, ArH-2,6), 7.42
(12H, m, PhH), 7.25 (8H, m, PhH). 19F{1H} NMR
1
7.46 (14H, m, ArH), 7.27 (4H, m, ArH), 7.18 (10H, m,
(CDCl3) ꢀ62.96 (s, CF3). 31P{1H} NMR (CDCl3) 22.1 (s,
ArH). 19F{1H} NMR (CDCl3) ꢀ62.69 (s, CF3). 31P{1H}
1JPtP 2685, trans), 15.9 (s, JPtP 3630, cis).
1
1
NMR (CDCl3) 15.1 (s, JPtP 3653).
3. Results and discussion
2.3.6. cis- and trans-[PtCl2{Ph2P(C6H4-3-C8F17)}2]
Anal. Calc. for C52H28Cl2F34P2Pt: C, 35.35; H, 1.72.
Found: C, 34.15; H, 1.73%. m/z (FAB) 1591 (MꢀCl)+.
1H NMR (CDCl3) 8.00–7.20 (28H, m, ArH). 19F{1H}
NMR (CDCl3) ꢀ80.91 (6F, m, CF3), ꢀ111.01 (4F, m, a-
CF2), ꢀ121.19 (4F, m, CF2), ꢀ121.81 (12F, m, 3 · CF2),
ꢀ122.67 (4F, m, CF2), ꢀ126.08 (4F, m, CF2). 31P{1H}
Measuring 1JPtP for cis-[PtCl2L2] (L = triarylphosphine)
is a very useful tool for the characterisation of platinum
complexes, with the magnitude of the coupling constant
being a predictive function of the triarylphosphine ligand,
and Pringle et al. have shown that these values correlate
very well with the Hammett rp parameter of the substituent
Ph3-nP
R
Ph3-nP
Ph2P
n
R
n
R
n =1 (1); n = 2 (2); n = 3 (3)
n =1 (4); n = 3 (5)
(6)
R
R
R
C6F13
P
Ph3-nP
2
R
n
n =1 (7); n = 2 (8); n = 3 (9)
(10)
R
a R = CF3; b R = C6F13; c R = C8F17; d R = C2H4C6F13;
e R = C3H6C6F13; f R = SiMe2C2H4C6F13; g R = OCH2C7F15
h R = OC3H6C8F17; i R = H; j R = F; k R = Cl; l R = Br;
m R = Me; p R = OMe; q R = NMe2
PPh2
PPh2
R
(11)
Fig. 1. Phosphines used in this study.

D.J. Adams et al. / Polyhedron 26 (2007) 1505–1513
1511
on the aryl ring [30]. We have previously used this tech-
nique to probe the effect of perfluoroalkylation on the
donor properties of triarylphosphines [13]. However, sys-
tematic comparison of the electronic impact of the perflu-
oroalkyl-substituent is not always possible since, as a
consequence of steric constraints, some cis-[PtCl2L2] com-
plexes are not available. Furthermore, even where the com-
plexes can be formed, it is difficult to be certain that the
effect being probed is entirely electronic. For example, the
1JPtP values for the cis-[PtCl2L2] complexes derived from
Ph2P(C6H4-4-C6F13)
and
Ph2P(C6H4-3-C6F13)
are
3653 Hz [13] and 3635 Hz [14], respectively, although it
Table 2
Coupling constant data for phosphorus(V) selenides and cis-/trans-[PtCl2L2] complexesa
1
b
1
c
1
d
1
e
Phosphine
Substituent
j JSeP
j
DJSeP
j JSeP
j
j JPtP
j
j
JPtP
j
3q
3p
3m
3h
3e
3g
3i
NMe2
OMe
Me
OC3H6C8F17
C3H6C6F13
OCH2C7F15
H
SiMe2C2H4C6F13
C2H4C6F13
F
683f
710h
715h
715
725
729
730
730
733
741h
748
748
741
743
742
742
744
744
752
757
756
755
758
758
765h
769
insol.
766h
772
773
779
785
780
785
803
739
743
749
ꢀ53
ꢀ20
ꢀ15
ꢀ15
ꢀ5
ꢀ1
0
3747g
3707g
3691g
746
754
764
759
767
766
767
772
775
778
774
774
775
3679
3680i
3675g
3673
3679k
3666l
3648g
3646
3653
2614
2635j
2632
1f
0
3
3d
3j
11
18
18
11
13
12
12
14
14
22
27
26
25
28
28
35
39
3k
3l
Cl
Br
CF3
1a
1b
1c
4a
4b
4c
6a
6b
2b
7a
7b
7c
3a
3b
3c
5a
5b
5c
8a
8b
10a
10b
9a
11i
11d
11b
a
2656
2664
C6F13
C8F17
CF3
C6F13
C8F17
CF3
C6F13
C6F13
CF3
C6F13
C8F17
CF3
C6F13
C8F17
CF3
C6F13
C8F17
CF3
C6F13
CF3/C6F13
C6F13
CF3
3653m
3653
3653
774
3633n
3650
2646n
2663
2805o
2826o
791
782
784
785
3635m
3630
2685
3630p
3622p
3611g
3615m
3570
2692p
2695p
792
793
2712m
2741
2720l
2723n
36
42
43
49
55
50
55
73
0q
3608l
796
801
806
801
803
817
2739p
2741p
2741p
2744p
2786l
3591p
3576p
3621l
3665r
3665r
3636r
H
C2H4C6F13
C6F13
4q
10q
Data (Hz) recorded for compounds dissolved in CDCl3 unless otherwise stated.
DJSeP = j JSePj(L) ꢀ j JSePj(PPh3) unless otherwise stated.
b
c
1
1
Diethyl ether.
cis-[PtCl2L2].
trans-[PtCl2L2].
d
e
f
Data from Ref. 28.
Data from Ref. 30.
Data from Ref. 16.
Data from Ref. 31.
Data from Ref. 32.
Data from Ref. 33.
Data from Ref. 22.
Data from Ref. 13.
Data from Ref. 14.
Data from Ref. 34.
Data taken from Ref. 22.
g
h
i
j
k
l
m
n
o
p
q
r
1
1
DJSeP = j JSePj(L) ꢀ j JSePj (11i).
Data taken from Ref. 25.

1512
D.J. Adams et al. / Polyhedron 26 (2007) 1505–1513
would be anticipated that placing the perfluoroalkyl group
in the para- or meta-position would have little effect on the
electronic properties of the phosphine and, indeed, Howell
et al. report that the electron-withdrawing effect of the
purely inductive CF3 is felt almost equally at the ortho-,
meta- and para-positions [16].
pendent of their position in these phosphines. As indi-
cated above, this effect is not apparent from the JPtP
1
values for pairs of cis-[PtCl2L2] complexes, particularly
since all attempts at forming cis-[PtCl2L2] for phosphine
8b failed, presumably due to steric congestion. However,
in direct contrast to the observations of Howell et al.,
[16] this cannot be extended to the ortho-substituted phos-
In order to fully understand the electronic influence of
perfluoroalkyl substituents on the donor properties of tri-
arylphosphines, we have prepared a comprehensive series
of phosphorus(V) selenides from a range of triaryl phos-
phines (Fig. 1). NMR spectroscopic data for these com-
pounds, alongside those for the cis-[PtCl2L2] complexes
and selected values from the literature, are presented in
1
phines, 6a and 6b, where j JSePj for their selenides are
substantially different to those for the selenides of 1a,
4a, 1b and 4b. This type of effect has, for the ortho-meth-
ylated triarylphosphine selenides, been attributed to the
steric impact of the substituents, [17] and this could
equally apply to our fluoroalkylated phosphine selenides.
An alternative explanation arises from through space
interactions between the phosphorus and fluorine atoms
[34]. This is clearly evident in the free phosphines
1
Table 2. The NMR data, in particular the j JSePj coupling
constants, [15] are solvent dependent and this must be
borne in mind in any comparison. Unfortunately, not all
the phosphorus(V) selenides are soluble in either CDCl3
or diethyl ether so, in order to offer a comprehensive anal-
ysis, data for many of the compounds are reported for both
solvents; the correlations discussed below apply equally
well to both sets of data.
4
4
(R = C6F13, JPF = 99 Hz; R = CF3, JPF = 53 Hz) and,
although the magnitude of the interaction is reduced in
the phosphine selenides (R = C6F13, 4JPF = 10 Hz;
4
R = CF3, JPF = 3 Hz), its presence is likely to seriously
alter the electronic properties of the phosphorus atoms
and hence the P–Se interaction.
These data reveal a number of significant facts. Firstly,
as reported previously for the CF3-derivatised aryl phos-
As expected, since both parameters are affected by the
electronic environment of the phosphine, there is a linear
1
phines, [16] the j JSePj values for the C6F13 derivatised
1
1
phosphorus(V) selenides are cumulative. So, DJPSe (rela-
tive to Se = PPh3) for the selenide derived from P(C6H4-
4-C6F13)3, 3b, is three times that for the selenide derived
from Ph2P(C6H4-4-C6F13), 1b. Similarly, that from 8b
gives a value four times greater than that from 1b. Sec-
ondly, despite various anecdotal, spectroscopic and cata-
lytic evidence to the contrary, the lengths of the
perfluoroalkyl substituents have no impact upon the elec-
tronic environment at phosphorus since DJSeP for related
series (phosphines = 1a, 1b and 1c; 3a, 3b and 3c; 4a, 4b
and 4c; 5a, 5b and 5c; 6a and 6b; 7a, 7b and 7c) are vir-
tually identical. Finally, since the values from the meta-
and para-substituted phosphines (1a, 1b and 1c; 4a, 4b
and 4c) are very similar and those from 10b and 8b give
identical results, the electron-withdrawing effect of the
perfluoroalkyl groups on the phosphorus centre is inde-
relationship between j JSePj and j JPtPj for both the cis-,
Fig. 2, and trans-[PtCl2L2] complexes, Fig. 3. The only
data point which does not show the linear correlation in
Fig. 2 is that for the cis-[PtCl2(9a)2] quoted by Alt et al.
[22]. However, although DJSeP for the selenide of 9a is
entirely consistent with the presence of six CF3 groups,
we were unable to prepare the cis-platinum metal complex
1
to confirm the magnitude of this JPtP coupling constant.
In contrast, in Fig. 3, the data for trans-[PtCl2(9a)2] is
consistent with the linear correlation. In Fig. 3, the data
points associated with phosphines 6a and 6b do not fol-
low the linear correlation, which is accounted for by the
additional steric and electronic interactions in both their
selenides and platinum metal complexes [34].
Many attempts have been made to minimise the electronic
effect of fluoroalkyl groups on the donor properties of the
810
800
790
780
770
760
750
740
730
720
820
800
780
760
740
720
700
680
660
2600
2650
2700
2750
2800
2850
3550
3600
3650
3700
3750
3800
|J(PtP)| /Hz
|J(PtP)| / Hz
L = P{C6H3-3,5-(CF3)2}3
L = PPh2(C6H4-2-CF3).
L = PPh2(C6H4-2-C6F13)
1
1
1
Fig. 2. Correlation between j JSePj for trisarylphosphine selenides and
Fig. 3. Correlation between j JSePj for Se = PR3 and j JPtPj for trans-
1
j JPtPj for cis-[PtCl2L2].
[PtCl2(PR3)2].

D.J. Adams et al. / Polyhedron 26 (2007) 1505–1513
1513
´
Table 3
[2] D. Rutherford, J.J.J. Juliette, C. Rocaboy, I.T. Horvath, J.A.
1
Influence of electronic spacer units on j JSePj coupling constants for
Gladysz, Catal. Today 42 (1998) 381.
Se = P(4-C6H4R)3
[3] E. de Wolf, E.A. Speets, B.-J. Deelman, G. van Koten, Organomet-
allics 20 (2001) 3686.
1
R
Label
j JSePj (CDCl3) (Hz)
DJSeP (Hz)a
[4] (a) S. Schneider, W. Bannwarth, Helv. Chim. Acta 84 (2001) 735;
(b) C. Markert, W. Bannwarth, Helv. Chim. Acta 85 (2002) 1877;
(c) C.C. Tzschucke, W. Bannwarth, Helv. Chim. Acta 87 (2004) 2882.
[5] L.P. Barthel-Rosa, J.A. Gladysz, Coord. Chem. Rev. 190–192 (1999)
587.
OMe
Me
3p
3m
3h
3e
3g
3i
710
715
715
725
729
730
733
765
769
ꢀ20
ꢀ15
ꢀ15
ꢀ5
ꢀ1
0
3
35
39
OCH2CH2CH2C8F17
CH2CH2CH2C6F13
OCH2C7F15
H
CH2CH2C6F13
CF3
´
[6] (a) D. Sinou, D. Maillard, A. Aghmiz, A.M. Masdeu I-Bulto, Adv.
Synth. Catal. 345 (2003) 603;
3d
3a
3b
(b) B. Richter, E. de Wolf, G. van Koten, B.-J. Deelman, J. Org.
Chem. 65 (2000) 3885;
(c) M. Wende, F. Seidel, J.A. Gladysz, J. Fluorine Chem. 124 (2003)
45.
C6F13
a
1
1
DJSeP = j JSePj(L) ꢀ j JSePj(PPh3).
[7] P. Bhattacharyya, D. Gudmunsen, E.G. Hope, R.D.W. Kemmitt,
D.R. Paige, A.M. Stuart, J. Chem. Soc., Perkin Trans. I (1997) 3609.
[8] (a) W. Chen, L. Xu, J. Xiao, Org. Lett. 2 (2000) 2675;
(b) S. Darses, M. Pucheault, J.-P. Genet, Eur. J. Org. Chem. (2002)
269.
[9] (a) D. Sinou, G. Pozzi, E.G. Hope, A.M. Stuart, Tetrahedron Lett. 40
(1999) 849;
(b) D. Sinou, D. Maillard, G. Pozzi, Eur. J. Org. Chem. (2001) 1121.
[10] E. de Wolf, B. Richter, B.-J. Deelman, G. van Koten, J. Org. Chem.
65 (2000) 5424.
[11] H. Jiao, S. Le Stang, T. Soos, R. Meier, K. Kowski, P. Rademacher,
L. Jafarpour, J.-B. Hamard, S.P. Nolan, J.A. Gladysz, J. Am. Chem.
Soc. 124 (2002) 1516.
[12] T. Soos, B.L. Bennett, D. Rutherford, L.P. Barthel-Rosa, J.A.
Gladysz, Organometallics 20 (2001) 3079.
[13] J. Fawcett, E.G. Hope, R.D.W. Kemmitt, D.R. Paige, D.R. Russell,
A.M. Stuart, J. Chem. Soc. Dalton Trans. (1998) 3751.
[14] E.G. Hope, R.D.W. Kemmitt, D.R. Paige, A.M. Stuart, D.R.W.
Wood, Polyhedron 18 (1999) 2913.
phosphines, which has been achieved by the introduction of
spacer groups between the perfluoroalkyl group and the aro-
matic ring. By examining the 1JSeP data it is possible to deter-
mine the efficiency of these groups at insulating the
phosphorus centre from the perfluoroalkyl groups and illus-
trative data are collected in Table 3. It can be seen that, using
these different perfluoroalkyl groups, it is possible to gener-
ate a range of different electronic environments at the phos-
phorus atoms. For these triarylphosphines, additional CH2
spacer units can provide insulation of the phosphorus atom
from the perfluoroalkyl groups, but at least two are required
for complete insulation. Finally, by using spacer groups
incorporating an oxygen atom, it is possible to generate
phosphines for use in a perfluorocarbon solvent that are
actually electron rich, as illustrated by the data for the
OCH2CH2CH2 (3h) spacer group substituted phosphine that
gives the same 1JSeP as tris(4-tolyl)phosphine selenide (3m).
1
[15] We note that JSeP is negative: W. McFarlane, J.A. Nash, J. Chem.
Soc. Chem. Commun. (1969) 913.
[16] J.A.S. Howell, N. Fey, J.D. Lovatt, P.C. Yates, P. McArdle, D.
Cunningham, E. Sadeh, H.E. Gottlieb, Z. Goldschmidt, M.B.
Hursthouse, M.E. Light, J. Chem. Soc. Dalton Trans. (1999)
3015.
4. Conclusions
1
[17] R.P. Pinnell, C.A. Megerle, S.L. Manatt, P.A. Kroon, J. Am. Chem.
Soc. 95 (1973) 977.
The JSeP coupling constants of a series of trisarylphos-
phines derivatised with a variety of different perfluoroalkyl
groups have been measured, which allow the direct com-
parison between phosphine ligands that is not possible
via other spectroscopic probes. The values have been used
to compare a range of different fluorinated groups and to
determine the efficiency of a variety of spacer groups at
insulating the phosphorus centre from the electron-with-
drawing effect of the perfluoroalkyl group. This data illus-
trates that it is possible to generate phosphines for use in
fluorous catalysis that are either electron rich, electron neu-
tral or electron poor with respect to triphenylphosphine.
[18] F.R. Hartley, C.A. McAuliffe, Inorg. Chem. 18 (1979) 1394.
[19] R. De Ketelaere, E. Muylle, W. Vanermen, E. Claeys, G.P. Van Der
Kelen, Bull. Soc. Chim. Belges 78 (1969) 219.
[20] P.D. Bartlett, G. Meguerian, J. Am. Chem. Soc. 78 (1956) 3710.
[21] V. Ravindar, H. Hemling, H. Schumann, J. Blum, Synth. Commun.
22 (1992) 841.
[22] H.G. Alt, R. Baumgaertner, H.A. Brune, Chem. Ber. 119 (1986) 1694.
[23] J. Porwisick, M. Schlosser, Chem. Ber. 129 (1996) 233.
[24] D.J. Adams, J.A. Bennett, D.J. Cole-Hamilton, E.G. Hope, J.
Hopewell, J. Kight, P. Pogorzelec, A.M. Stuart, Dalton Trans. (2005)
3862.
[25] E.G. Hope, A.M. Stuart, A.J. West, Green Chem. 6 (2004) 345.
[26] S.E. Tunney, J.K. Stille, J. Org. Chem. 52 (1987) 748.
[27] S. Schneider, W. Bannwarth, Angew. Chem., Int. Ed. 39 (2000) 4142.
[28] J. Malito, E.C. Alyea, Phosphorus Sulfur Silicon 54 (1990) 95.
[29] R.F. De Ketelaere, G.P. Van Der Kelen, Z. Eeckhaut, Phosphorus 5
(1974) 43.
[30] C.J. Cobley, P.G. Pringle, Inorg. Chim. Acta 265 (1997) 107.
[31] P. Bhattacharyya, B. Croxtall, J. Fawcett, J. Fawcett, D. Gudmun-
sen, E.G. Hope, R.D.W. Kemmitt, D.R. Paige, D.R. Russell, A.M.
Stuart, D.R.W. Wood, J. Fluorine Chem. 101 (2000) 247.
[32] J.P. Farr, F.E. Wood, A.L. Baulch, Inorg. Chem. 22 (1983) 3387.
[33] Q. Zhang, Z. Luo, D.P. Curran, J. Org. Chem. 65 (2000) 8866.
[34] B. Croxtall, J. Fawcett, E.G. Hope, A.M. Stuart, J. Chem. Soc.,
Dalton Trans. (2002) 491.
Acknowledgements
We thank the EPSRC (DJA, JAB, DD, AJW), Merck
(JAB, AJW), GSK (DD) and the Royal Society (AMS)
for financial support.
References
´
´
[1] I.T. Horvath, G. Kiss, R.A. Cook, J.E. Bond, P.A. Stevens, J. Rabai,
E.J. Mozeleski, J. Am. Chem. Soc. 120 (1998) 3133.