Amidinium based ionic liquids

Article abstract of DOI:10.1039/b9nj00625g

Three new series of mono-and bis-cyclic amidinium cations bearing alkyl chains of different length were synthesized. 53 salts were generated upon combining the cations with a variety of anions and their thermal behaviour was investigated. Depending on the structure and the charges state of the cyclic amidinium moiety and the nature of the anion, several of the obtained salts behaved as ionic liquids with their melting point in the range of ca. 25-94 °C.

Full text of DOI:10.1039/b9nj00625g

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PAPER
www.rsc.org/njc | New Journal of Chemistry
Amidinium based ionic liquidsw
Pierre Dechambenoit, Sylvie Ferlay,* Nathalie Kyritsakas and Mir Wais Hosseini*
Received (in Montpellier, France) 1st November 2009, Accepted 13th January 2010
First published as an Advance Article on the web 15th March 2010
DOI: 10.1039/b9nj00625g
Three new series of mono- and bis-cyclic amidinium cations bearing alkyl chains of different
length were synthesized. 53 salts were generated upon combining the cations with a variety of
anions and their thermal behaviour was investigated. Depending on the structure and the charges
state of the cyclic amidinium moiety and the nature of the anion, several of the obtained salts
behaved as ionic liquids with their melting point in the range of ca. 25–94 1C.
charge-assisted H-bonded networks18 in the crystalline
Introduction
phase by combining them with sulfonates, carboxylate,
polycyanometallates19–24 or polyoxalatometallate25 anions.
In order to obtain new families of ionic liquids based on
the amidinium group, one must prevent the crystallisation
processes. We thought that this could be achieved by decreasing
interactions between the cationic and anionic partners through
the replacement of hydrogen atoms involved in strong charge-
assisted H-bonding with anions by alkyl groups. Furthermore,
by rendering the amidinium group unsymmetrical through
differentiated alkylation (introduction of a methyl and an
alkyl groups of variable chain length), one should further
reduce the crystallisation ability of the salt.
The design and discovery of ionic liquids (ILs) displaying
melting points (mp) lower than 100 1C,1,2 in particular room
temperature ionic liquids (RTILs) and tasks specific ionic
liquids (TSILs) have been the subject of considerable efforts
over the past decade.3–10 The interest in this class of molecules
arises in part from their use as liquid media for a variety of
chemical transformation and as substitutes for volatile organic
solvents.
The majority of ILs belong to the family of N,N0-methyl-
(alkyl)imidazolium, alkyl-pyridinium or ammonium cations
ꢀ
associated with a variety of anions such as Xꢀ, BF4ꢀ, BPh4ꢀ
,
,
PF6ꢀ, NO3ꢀ, CF3SO3ꢀ, NCSꢀ, N(CN)2ꢀ, TfOꢀ, NTf2
TsOꢀ, AlCl4 or MX4ꢀ. Recently, a few amidinium-based
ionic liquids have been also reported.11,12 The many opportunities
arising from all the possible combinations of cations and
anions allow to tune with good precision the characteristics
of ionic liquids such as melting point, viscosity, hygroscopy,
dielectric constant etc. Consequently, this class of molecules
are increasingly used in many areas such as organic chemistry,
chemical engineering, material sciences, physical chemistry,
analytical chemistry, biotechnology and energy storage.13–15
For the reasons mentioned above, the development of new
classes of ionic liquids is a topic of current interest. By analogy
with imidazolium cation based ionic liquids, the use of the
cyclic amidinium backbone appeared to us as an interesting
alternative.
ꢀ
(a) Design
The design of all three series (Scheme 1) is based on the use of
the benzamidine group. The rationale behind this choice is to
render the cationic backbone more robust towards hydrolysis.
Whereas the design of the two series A and B is based on
monocationic cyclic amidinium derivatives bearing two different
alkyl groups (one methyl and one alkyl chain with variable
length), for the design of the third series C, a dicationic
bis-cyclic amidinium backbone, for which each amidinium
group bears one methyl group and one alkyl fragment of
variable length, is used. As stated above, the alkylation of the
monoamidines (series A and B) and the bisamidine (series C)
was performed in order to prevent strong H-bonding between
the cationic moiety and anions and thus to avoid the
generation of crystalline materials. The double alkylation of
the amidine by two different alkyl groups was performed in
order to introduce dissymmetry and thus again to prevent as
much as possible the crystallisation processes. The use of the
methyl group was motivated by synthetic reasons since the
Here, we report on the design, synthesis, thermal behaviour
and structural studies of three new series of mono- and
bis-amidinium cations (Scheme 1) combined with a variety
of anions.
Results and discussion
We have extensively used a variety of dicationic bisamidinium
derivatives16 as tectons17 for the design and generation of
Laboratoire de Chimie de Coordination Organique,
´
UMR CNRS 7140, Universite de Strasbourg,
Institut Le Bel, 4, rue Blaise Pascal, F-67000 Strasbourg, France.
E-mail: hosseini@unistra.fr, ferlay@unistra.fr; Fax: +33 390241325;
Tel: +33 390241323
w CCDC reference numbers 753161–753169. For crystallographic data
in CIF or other electronic format see DOI: 10.1039/b9nj00625g
Scheme
1
Target N-alkylated cyclic amidinium cations, R =
CH3(CH2)n (n = 2, 5, 11) for five-membered (A) and six-membered
(B) cyclic monoamidinium and R = CH3(CH2)n (n = 2, 5, 11, 15) for
bis-cyclic bisamidinium (C) compounds.
ꢁc
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monomethyl-, ethylene- and propylene-diamines are commercially
available. The preparation of the bisamidinium salts (series C)
is justified by the fact that only very few examples of ionic
liquids based on dicationic units have been reported.26–33
Finally, it is worth noting that, the three series spotted in this
investigations can be obtained easily in large quantities and at
rather low cost.
(b) Synthesis
A general and versatile synthetic strategy was used for the
preparation of the mono and biscationic amidinium derivatives
4–13 (Scheme 2). Following the methodology reported by
Lever34, monoamidines 1 and 2 have been prepared as their
hydrochloride salts in 47 and 70% yields, respectively, upon
condensation of monomethyl ethylenediamine or monomethyl
propanediamine with benzonitrile in the presence of catalytic
amount of P2S5. Using the same method, the bisamidine
3 was synthesised in 66% yield as its hydrochloride salt
upon condensation of monomethyl propanediamine with
1,4-dicyanobenzene again in the presence of catalytic amount
of P2S5.34 The desired monoamidinium cations 4–9 have been
obtained by simple condensation of the monoamidines 1 or 2
with terminal alkylhalides. In order to study the role played by
the counter ion (Clꢀ, Brꢀ, Iꢀ, BF4ꢀ, BPh4ꢀ, PF6ꢀ, OTfꢀ
(trifluoromethanesulfonate) or NTf2 (bis(trifluoromethane)-
sulfonimidate)), different salts of the cationic derivatives
4–13 have been prepared by anion metathesis. For corres-
pondence between numbers assigned to different salts see
Table 1. Both in the case of 1 and 2, the alkylation reaction
leading to the monoamidinium salts (4+, Iꢀ) = 24, (5+, Brꢀ) =
27, (6+, Brꢀ) = 30, (7+, Iꢀ) = 33, (8+, Brꢀ) = 38, and
(9+, Brꢀ) = 43 was carried out with iodo-1-propane, bro-
mo-1-hexane and bromo-1-dodecane respectively. The yield of
the reaction was in the 46–60% range (see Experimental
section). The anion exchange proceeded in 85–99% yield in
both cases. The synthesis of dicationic compounds 10–13 was
achieved by condensation of 3 with terminal alkylhalides. The
alkylation reaction was achieved using iodo-1-propane, bro-
mo-1-hexane, bromo-1-dodecane and bromo-1-hexadecane. The
bisamidinium salts (102+, Iꢀ) = 48, (112+, Brꢀ) = 53,
(122+, Brꢀ) = 58 and (132+, Brꢀ) = 63, were obtained in
60–80% yield (see Experimental section). Again, the anion
metathesis proceeded with almost quantitative yields.
Scheme 2 Synthetic strategies used for the preparation of Xn+
(X = 1–13, n = 1 or 2).
Table 1 Numbers attributed to different prepared salts. For
structures of compounds 1–13 see Scheme 2
Clꢀ Brꢀ Iꢀ BF4
BPh4
PF6
OTfꢀ NTf2
ꢀ
ꢀ
ꢀ
ꢀ
1-H+
2-H+
14
17
15
19
16
20
18
24
21
22
3-2H+ 23
4+
25
28
31
34
39
44
50
55
60
65
26
29
32
35
40
45
51
56
61
66
5+
27
30
6+
7+
33
36
41
46
37
42
47
52
57
62
67
8+
38
43
(c) Thermal behaviour
9+
102+
112+
122+
132+
48 49
54
59
The thermal behaviour as well as the physical state (solid,
liquid) of all salts of the monocationic amidinium 4+–6+,
7+–9+ as well as the dicationic bisamidinium derivatives
102+–132+ are given in Tables 2–4.
53
58
63
64
(1) Salts of monoamidinium cations 1-H+ and 4+–6+
Table 2 Mp (1C) for 1-H+, 4+–6+ cations associated with different
anions; L = liquid, V = viscous
The chloride salt 14 and the iodide salt 24 were found to be
rather hygroscopic. Among the 12 derivatives prepared in this
series based on the ethylene spacer, 5 of them (24, 27, 29, 30
and 32) are viscous liquids at room temperature (see Table 2).
For the other 7 salts, the melting point was in the range of
63–162 1C. Depending on the nature of the anion used, some
of the compounds were thermally stable up to 350 1C (Fig. 1).
Clꢀ
Iꢀ
Brꢀ
BPh4
ꢀ
ꢀ
PF6
1-H+
4+
160 (14)
—
—
—
VL (27)
VL (30)
160 (15)
162 (25)
114 (28)
69 (31)
149 (16)
63 (26)
VL (29)
VL (32)
—
—
—
VL (24)
—
—
5+
6+
ꢁc
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Table 3 Mp (1C) for 2-H+, 7+–9+ cations associated with different
anions (Iꢀ, Clꢀ, Brꢀ, PF6ꢀ, BPh4ꢀ, OTfꢀ and NTf2ꢀ) (17–22 and
33–47); L = liquid
ꢀ
ꢀ
ꢀ
OTfꢀ NTf2
Clꢀ
Brꢀ
Iꢀ
BPh4
PF6
2-H+ 160 (17) —
177 (18) 205 (19) 138 (20)
88 (33) 119 (34) 93 (35)
76 (21) L (22)
L (36) L (37)
7+
8+
9+
—
—
—
—
L (38)
—
49 (43) —
94 (39) 41–47 (40) L (41) L (42)
92 (44) 49–51 (45) L (46) L (47)
If applying the definition of the ionic liquid state (melting
point below 100 1C), only compounds 26 and 31 may be of
interest as ionic liquids. Indeed, the hexafluorophosphate salt
of the monocation 4+ (salt 26) and the tetraphenylborate salt
of the monoamidinium 6+ (salt 31) display melting points
between 60 and 70 1C.
Fig. 1 TGA trace for different salts: 18 (blue), 19 (violet), 42 (red) and
44 (green).
(2) Salts of monoamidinium cations 2-H+ and 7+–9+
The aromatic and the five-membered rings are not coplanar
but tilted by 511. In 26, the propyl chain is extended with a
C–C–C angles of 114.31 (see Fig. 2, bottom). In both cases,
there are no specific interactions between the anionic and the
cationic parts.
Some of the prepared salt in this series are also extremely
hygroscopic. The bromide salt of 8+ (38), the triflate salts of
7+ (36), 8+ (41) and 9+ (46) as well as all the bis(trifluoro-
methane)sulfonimidate (NTfꢀ) salts of 2-H+ and 7+–9+ were
found to be liquids (see Table 3). Again, depending on the
anion, some of the salts are stable up to 350 1C (Fig. 1).
Interestingly, among the 21 different salts prepared, five
(17–20 and 34) display melting points above 100 1C. For the
other 16 derivatives, either they are liquids at room temperature
or their melting points are in the range of 41–94 1C and thus
may be considered as ionic liquids.
For the family B composed of monoamidinium cations
based on the propylene spacer, crystals of the iodide (18,
monoclinic, P21/n, Fig. 3), triflate (20, monoclinic, P21/c)
and hexafluorophosphate (21, orthorhombic, Pbca) salts of
2-H+ and the tetraphenylborate salt of 7+ (34, orthorhombic,
Pna21) were obtained (see crystallographic table, Table 5). The
X-ray diffraction study revealed that in all cases, the C–N
distances for the six-membered cyclic amidinium moiety is
in the range 1.3210(17)–1.326(6) A which is close to that
mentioned above for the family A. The six-membered ring
adopts a half chair conformation with the NCC angle varying
between 112.0(3) and 108.05(12)1. Again, as in the case of 4+
mentioned above, the aromatic and the six-membered rings
are tilted by 501. For the iodide salt 18, a view of the packing
of cations and anions given in Fig. 2 shows weak interactions
through H-bonds between amidinium and iodide with Nꢂ ꢂ ꢂI
distances of 3.49 and 4.53 A.
(3) Salts of bisamidinium dications 3-2H+ and 102+–132+
ꢀ
As a general observation, except for the NTf2 salts of
102+–132+ for which the melting points are below 150 1C,
only one compound 57 (mp of 70 1C) may be considered as an
ionic liquid. For all the other salts, high melting points were
recorded (see Table 4). For these salts, some of the melting
points are higher than their decomposition temperature
(Fig. 1). Thus, unfortunately, among the 21 salts prepared,
only one (salt 57) may be of interest as an ionic liquid.
In the case of 21, the triflate salt of 2-H+, a strong H-bond
(dN–O = 2.82 A) between the sulfonate group and the
amidinium moiety of 2-H+ is observed (Fig. 4).
(d) Structural studies
For some of the salts displaying rather high melting point, we
were able to grow single crystals suitable for structural analysis
by X-ray diffraction methods (see crystallographic Table 5).
For the family A, only the tetraphenylborate salt of 1-H+
(15) (monoclinic, P21/n, Fig. 2, top) and the hexafluoro-
phosphate salt of 4+ (26) (monoclinic, C2/c, Fig. 2, bottom)
were obtained as crystalline materials. The X-ray diffraction
study revealed that in both cases, the C–N distances for the
cyclic amidinium moiety are in the range 1.314(2)–1.322(3) A.
For the tetraphenylborate salt of 7+ (compound 34), the
C–N distances for the amidinium moiety are in the range
of 1.322(2) and 1.325(2) A. The conformation of the six-
membered ring cycle is again a half chair with a NCC angle
of 110.44(14)1. The aromatic ring and the six-membered cycle
are almost perpendicular with a tilt angle of 781 (Fig. 5). The
propyl chain is again extended with a C–C–C angle of
113.42(17)1.
Table 4 Mp (1C) for 3-2H+, 102+–132+ (23 and 48–67) cations associated with different anions (Brꢀ, Iꢀ, BF4ꢀ, PF6ꢀ, BPh4 and NTf2ꢀ);
ꢀ
*: decomposition
ꢀ
ꢀ
ꢀ
ꢀ
Clꢀ
Brꢀ
Iꢀ
BF4
BPh4
PF6
—
NTf2
3-2H+
102+
112+
122+
132+
B250* (23)
—
—
—
>340* (48)
—
—
—
—
—
—
134–135 (52)
70 (57)
106–108 (62)
103–106 (67)
—
—
—
—
>340* (49)
306–308 (54)
>340* (59)
>300* (64)
314–316* (50)
>300* (55)
>300* (60)
235 (65)
>320* (51)
314 (56)
>280* (61)
B 280* (66)
>280* (53)
>300* (58)
>300* (63)
ꢁc
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Table 5 Crystallographic parameters for 15, 18, 20, 21, 23, 26, 34, 48 and 59 recorded at 173 K
Compound
Formula
15
18
20
21
23
16H24N4Cl2ꢂ
34H33BN2 C11H15IN2 C11H15F6N2P C12H15F3N2O3S 4H2O
26
34
48
59
C40H72N4Br2
C
C
C13H19N2F6P C38H41BN2
348.27 536.54
C22H36N4I2 ꢂ3H2O
610.35 822.88
Molecular
weight
Crystal system Monoclinic Monoclinic Monoclinic Orthorhombic Monoclinic Monoclinic Orthorhombic Monoclinic Triclinic
Space group
a/A
b/A
c/A
a/1
b/1
480.43 302.15 320.22 324.32 415.36
ꢀ
P21/n
9.7552(9) 6.60500(10) 15.4539(12) 11.0219(4)
15.9976(13) 15.5700(3) 12.1945(7) 15.3857(5)
17.3840(16) 11.7069(2) 15.6621(12) 16.9442(6)
90
99.527(2) 97.5510(10) 113.353(2
90 90 90
2675.5(4) 1193.50(4) 2709.8(3)
P21/n
P21/c
Pbca
P21/n
C2/c
15.8396(12) 18.620(3)
7.3779(6)
26.074(2)
90
Pna21
P21/n
P1
9.8040(3)
9.3589(2)
11.3818(3)
90
7.6986(4) 7.4346(2)
13.1654(8) 12.6309(3)
12.2445(8) 24.8045(7)
90
98.824(2) 88.3960(10)
90 73.3400(10)
1226.35(13) 2207.33(10)
16.793(2)
9.9862(9)
90
90
90
90
90
90
90
81.5990(10)
95.5590(10) 92.798(2)
90
g/1
90
2873.39(17)
8
90
1039.42(5)
2
V/A3
3043.4(4)
8
3122.5(7)
4
Z
4
4
8
2
2
Colour
Dimensions/
mm3
Colourless Colourless Colourless
0.10 ꢃ 0.20 ꢃ 0.12 ꢃ
Colourless
0.20 ꢃ
Colourless
0.21 ꢃ
Colourless
0.12 ꢃ
Colourless
0.20 ꢃ
Colourless Colourless
0.10 ꢃ 0.10 ꢃ
0.06 ꢃ 0.06 0.18 ꢃ 0.17 0.10 ꢃ 0.06 0.15 ꢃ 0.13
0.13 ꢃ 0.12 0.10 ꢃ 0.05 0.16 ꢃ 0.08
0.05 ꢃ 0.05 0.10 ꢃ 0.08
Dc/g cmꢀ3
F(000)
m/mmꢀ1
l/A
1.193
1024
1.682
592
1.570
1312
1.499
1344
0.270
0.71073
56466
4217
1.327
444
0.340
0.71073
12120
2388
1.520
1440
0.242
0.71073
12587
3523
1.141
1152
0.065
0.71073
32310
6364
1.653
604
1.238
880
0.068
0.71073
2.649
0.71073
18778
3355
0.264
0.71073
21182
7374
2.579
0.71073
19439
3545
1.874
0.71073
49155
13224
No. data meas. 17812
No. data with I 6100
> 2s(I)
Rint
0.0416
0.0302
0.0286
0.0597
0.0424
0.0626
1.050
0.0934
0.0878
0.2234
0.2109
0.3527
1.012
0.0412
0.0365
0.0910
0.0622
0.0992
1.074
0.0341
0.0452
0.1184
0.0538
0.1248
1.048
0.0294
0.0523
0.1585
0.0759
0.1791
1.028
0.0452
0.0357
0.0773
0.0539
0.0843
1.013
0.0368
0.0290
0.0762
0.0383
0.0796
1.054
0.0244
0.0593
0.1862
0.0771
0.2004
1.035
R1 (I > 2s(I)) 0.0487
wR2 (I > 2s(I)) 0.1115
R1 (all)
wR2 (all)
GOF
0.1043
0.1414
1.016
Drmax, min
/
0.185,
ꢀ0.210
1.387,
ꢀ1.289
0.741,
ꢀ0.835
0.277,
ꢀ0.368
0.490,
ꢀ0.442
0.615,
ꢀ0.476
0.143,
ꢀ0.145
1.321,
ꢀ0.599
1.781,
ꢀ2.258
e Aꢀ3
Fig. 3 A portion of the crystal structure of 18 (projection in the [100]
plane) showing the presence of the H-bond. For distances and angles
see text. H-atoms, except those involved in H-bonding with iodide
anion, are not represented for clarity.
distances for 3-2H+ dication are in the range of
1.315(2)–1.322(2) A (Fig. 6). The conformation of the two
six-membered cycles is, as expected, a half chair with a NCC
angle of 116.49(16)1. The aromatic ring and the cyclic amidinium
cycles are not coplanar but tilted with an angle of 108.17(16)
and 110.82(17)1. The packing of the cationic and anionic
partners shows a hydrogen bond between the N–H centre of
the amidinium dication and chloride anion (dNꢀCl = 3.12 A)
(see Fig. 6 bottom). The crystal contains also four H2O
molecules in the unit cell. The water molecules are H-bonded
Fig. 2 A portion of the crystal structure of 15 (top) and 26 (bottom).
For distances and angles see text. H-atoms are not represented for
clarity.
For the dicationic bisamidinium derivates (family C), the
chloride salt of 3-2H2+ (23), the iodide salt of 102+ (48) and
the tetrafluoroborate salt of 122+ (59) could be obtained as
crystals (see crystallographic table, Table 5).
For the hydrochloride salt of 3+ (compound 23), in agreement
with the structure of other amidinium cations, the C–N
ꢁc
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Fig. 4 A portion of the crystal structure of 21 showing the presence of
an H-bond between the amidinium cation and the triflate anion. For
distances and angles see text. H-atoms, except those involved in
H-bonding with iodide anion, are not represented for clarity.
Fig. 6 A portion of the crystal structure of 23 showing the H-bond
between the Clꢀ anion and the amidinium moiety (top) and the
packing in the [010] plane and the formation of H-bonded networks
between water molecules and the ionic network (bottom). For
distances and angles see text. H-atoms, except those involved in
H-bonding with iodide anion, are not represented for clarity.
Fig. 5 A portion of the crystal structure of 34 showing the cationic
and the anionic parts. For distances and angles see text. H-atoms are
not represented for clarity.
with O–O distances of 2.88 and 2.86 A, leading to a 1D
polymeric network, that is connected to the ionic units
through OHꢂ ꢂ ꢂCl interactions (dO–Cl = 3.18 A) as well as
through Oꢂ ꢂ ꢂHN amidinium interactions (dO–N = 3.30 A).
Suitable crystals of both salts 48 and 59 have been also
obtained. The X-ray analysis revealed that the anionic and
cationic parts are separated without any specific interactions
between them. The bisamidinium moiety of 48 (the iodide salt
of 10-2H2+) is centrosymmetric (Fig. 7) and the C–N distances
of 1.320(3) and 1.324(3) A are again in the same range as that
observed for the other cases discussed above. Both six-
membered rings again adopt a half-chair conformation with
a NCC angle of 110.6(3)1. As for the hydrochloride salt 23, the
aromatic cycle is tilted with respect to the two amidinium
cycles with a tilt angle of 971. The propyl chain is extended
with a C–C–C angle of 112.5(2)1).
In marked contrast with the transoid conformation adopted
by the dication in 48, the bisamidinium moiety of 59 adopts
the cisoid conformation in the crystalline phase (Fig. 9). The
latter conformation results from the packing of the molecular
units leading to interdigitation of the alkyl chains (Fig. 8). One
of the two alkyl chains was found to be disordered. For the
amidinium unit, the C–N distances are again in the range of
1.314(4)–1.319(4) A. The conformation of the six-membered
cycle is also a half chair with a NCC angle of 110.6(4)1. The tilt
between the aromatic ring and the six-membered cycle is 89.01
which is less than those observed for 23 and 48. The dodecyl
chains are unfolded and located on the same face of the
amidinium unit and in the same plane. As mentioned above,
the packing of consecutive cationic units is achieved through
van der Waals interaction by interdigitation of the alkyl
chains (shortest C–C distances between chains belonging to
Fig. 7 A portion of the crystal structure of 48 showing the cationic
and the anionic (Iꢀ) parts. For distances and angles see text. H-atoms
are not represented for clarity.
consecutive units is 4.01 A). This mode of packing generates
hydrophobic layers of ca. 13 A thickness (see Fig. 9). The
water molecules present in the crystal form a H-bonded
network with Oꢂ ꢂ ꢂO distances varying between 2.74 and
2.81 A and are located outside the hydrophobic zones. The
Brꢀ anions are located above the charged cycles and are
interacting strongly with water molecules through H-bonds
(Oꢂ ꢂ ꢂBr distances in the range of 3.31–3.33 A).
Conclusions
Three series (A, B and C, see Scheme 1) of amidinium based
salts have been designed, synthesised and investigated for their
thermal behaviour. The first two series (A and B) are based on
a cyclic monoamidinium cation and differ only by the number
of methylene groups connecting the N atoms of the amidinium
group (two for A and three for B). The third family is
constructed around a dicationic bicyclic backbone.
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Fig. 10 Variation of the melting point (mp) as a function of the
ꢀ
ꢀ
length of the alkyl chain BPh4 and PF6 saltsꢀof monocationic
amidinium 4+ and 7+ associated with either BPh4 or PF6 anions
ꢀ
Fig. 8 A portion of the crystal structure of 59 showing the cationic
and the anionic (Brꢀ) parts. For distances and angles see text. H-atoms
are not represented for clarity.
(compounds 15, 16, 19, 20, 25, 26, 28, 31, 34, 35, 39, 40, 44 and 45).
Thermogravimetric (TGA) studies
TGA measurements have been performed on Pyris 6 TGA Lab
System (Perkin-Elmer), using a N2 flow of 20 ml minꢀ1 and a
heat rate of 10 1C minꢀ1
.
Single-crystal studies
Data were collected at 173(2) K on a Bruker APEX8 CCD
Diffractometer, equipped with an Oxford Cryosystem liquid
N2 device, using graphite-monochromated Mo-Ka (l =
0.71073 A) radiation. For all structures, diffraction data were
corrected for absorption. The structures were solved using
SHELXS-97 and refined by full-matrix least squares on F2
using SHELXL-97. The hydrogen atoms were introduced at
calculated positions and not refined (riding model).40
Fig. 9 A portion of the crystal structure of 59, view in the [100] plane.
Synthesis
For distances and angles see text.
Synthesis of 1. A saturated aqueous solution of sodium
hydroxide (8 ml) was mixed with 1.99 g (10.1 mmol) of 14
dissolved in 10 ml of distilled water. After stirring for 5 min,
the mixture was extracted into CH2Cl2 (2 ꢃ 25 ml), dried with
MgSO4. After filtration, the organic solvent was removed
under vacuum affording the pure compound 1 in 86% yield
as a slightly yellowish liquid which decomposed at 50 1C.
1H NMR (CDCl3, d ppm): 2.75 (s, 3H, CH3–N), 3.40–3.83
For the first two series composed of monocationic species
4+–9+, the chloride salts do not behave as ionic liquids
(mp >250 1C). As already observed for other IL,35 thꢀe melting
points are considerably lower for TfOꢀ and NTf2 anions
than for the other salts. Indeed, except for the compound 2ꢀ1
for which the melting point is 76 1C, all other TfOꢀ and NTf2
salts (22, 36, 37, 41, 42, 46 and 47) are liquid at room
temperature and thus can be used as ionic liquids.
3
(2t, 2H, J = 9.7 Hz, CH2–N), 7.3–7.5 (m, 5H, CH arom);
13C NMR (CDCl3, d ppm): 36.5 (CH3–N), 53.2–54.1 (CH2–N);
128.1–128.3 (CH arom, a and b), 129.7 (CH arom, g), 131.3
(C arom), 168.2 (N–C–N). Calc. for C10H12N2: C = 74.97%,
H = 7.55%, N = 17.48%. Found: C = 74.52%, H = 7.78%,
N = 17.65%.
A correlation between the length of the alkyl chain and the
measured melting points while using the same anion (mainly
BPh4ꢀ and PF6ꢀ) shows clearly that, as expected, the variation
of the melting point is inversely proportional to the chain
length (Fig. 10).36,37 This trend may be explained by the
increase of the dissymmetry of the cation.38,39
Synthesis of 2. 8 ml of a saturated aqueous solution of
sodium hydroxide was mixed with 2.15 g (12.3 mmol) of 17
dissolved in 10 ml of distilled water. After stirring for 5 min,
the mixture was extracted into CH2Cl2 (2 ꢃ 25 ml), dried with
MgSO4. After filtration, the organic solvent was removed
under vacuum affording the pure compound 2 in 85% yield
For the dicationic series, only the salt 57 (mp = 57 1C)
displays a melting points lower than 100 1C for all the other
salts prepared, melting points are higher than 250 1C and
usually above their decomposition temperature.
Experimental
1
as a slightly yellowish liquid. H NMR (CDCl3, d ppm): 1.90
(q, 2H, J = 5.7 Hz, CH2(CH2–N)2), 3.04 (s, 3H, CH3–N),
3
The NMR studies were performed at 25 1C on a Bruker
AC300 at 300 MHz for H and at 75 MHz for 13C.
3.24 (t, 2H, 3J = 5.7 Hz, CH2–N–CH3), 3.46 (t, 2H, 3J = 5.7 Hz,
1
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CH2–NH), 7.32 (m, 5H, CH arom). 13C NMR (CDCl3, d ppm):
22.0 (N–CH2–CH2–CH2–N), 40.3 (CH3–N), 44.9, 48.6
(CH2–N), 128.0, 128.5 (CH arom), 138.0 (C arom), 159.3
(N–C–N). Calc. for C11H14N2: C = 75.82%, H = 8.10%,
N = 16.08%. Found: C = 75.24%, H = 8.35%, N = 16.05%.
(C arom), 134.0 (CH arom, g), 163.2, 163.8, 164.5, 165.1, 166.2
(C arom, BPh4 and N–C–N). Calc. for C34H33BN2:
C = 85.00%, H = 6.92%, N = 5.83%; Found: C = 84.84%,
H = 6.96%, N = 5.90%.
Synthesis of 16. To a solution of 14 (318 mg, 1.82 mmol) in
of distilled water (5 ml) an aqueous solution (5 ml) of
ammonium hexafluorophosphate (415 mg, 2.55 mmol) was
added and the mixture stirred for 15 min. The white solid thus
formed was filtered off, washed with water (3 ꢃ 3 ml) and
dried under vacuum for 1 day affording the compound 16 as a
white solid in 82% yield. For X-ray diffraction analysis,
suitable colourless crystals were obtained upon slow diffusion
of acetone into a water–acetone mixture containing 16. Mp
149 1C (decomposition at 250 1C). 1H NMR ((CD3)2O,
d ppm): 3.28 (s, 3H, CH3–N), 4.26 (m, 4H, CH2–N), 7.6–7.8
(m, 5H, CH arom), 9.20 (NH); 13C NMR ((CD3)2O, d ppm):
33.9 (CH3–N), 43.0, 53.7 (CH2–N), 122.9 (C arom), 128.7,
129.4 (CH arom, a and b), 133.5 (CH arom, g), 167.0
(N–C–N). Calc. for C10H13F6N2P: C = 39.23%, H = 4.28%,
N = 9.15%. Found: C = 39.13%, H = 4.04%, N = 9.19%.
Synthesis of 3. To an aqueous solution (distilled, 200 ml) of
23 (5.0 g), a saturated solution of sodium hydroxide was added
until pH = 13 was reached. The white precipitate thus formed
was filtered off, washed with 2 ꢃ 15 ml of water and dried
under vacuum affording the pure compound 3 in 71% yield.
Mp 171 1C. 1H NMR (CD3OD, d ppm): 1.96 (q, 4H, 3J = 6.0 Hz,
3
CH2(CH2–N)2), 2.76 (s, 6H, CH3), 3.39 (q, 8H, J = 6.0 Hz,
CH2–N), 7.42 (s, 4H, CH arom); 13C NMR (CD3OD, d ppm):
21.5 (N–CH2–CH2–CH2–N), 39.2 (CH3–N), 43.5 (CH2–NH),
48.0 (CH2–N–CH3), 127.9 (CH arom), 137.9 (C arom),
160.0 (N–C–N). Calc. for C16H22N4.ꢂ2/3H2O: C = 68.05%,
H = 8.33%, N = 19.84%. Found: C = 68.05%, H = 8.22%,
N = 19.95%.
Synthesis of 14.
A mixture of benzonitrile (7.99 g,
77.5 mmol), N-methyl-1,2-ethylenediamine (5.74 g, 77.5 mmol)
and P2S5 (100 mg) was stirred and heated under argon for 4 h
at 160 1C before it was evaporated to dryness. The mixture was
treated with dilute aqueous HCl solution until pH 5 was
reached. The solution was then washed twice with CH2Cl2
and the aqueous phase was recovered and evaporated to
dryness. The brownish oil thus obtained was taken up in
EtOH (50 ml) and heated under reflux in the presence of
charcoal during 2 h. Filtration followed by evaporation and
drying afforded the compound 14 in 47% yield as a very
hygroscopic pale yellow solid. Mp B160 1C (decomposition at
210 1C). 1H NMR (D2O + tBuOH, d ppm): 3.12 (s, 3H,
CH3–N), 4.06 (m, 4H, CH2–N), 7.6 (m, 4H, CH arom, a and
b), 7.69–7.78 (m, 1H, CH arom, g); 13C NMR (D2O +
tBuOH, d ppm): 34.5 (CH3–N), 43.2–53.0 (CH2–N), 123.0
(C arom), 129.1, 129.9 (CH arom, a and b), 134.1 (CH arom,
g), 167.3 (N–C–N). Calc. for C10H13ClN2ꢂ1/4H2O: C =
59.70%, H = 6.76%, N = 13.92%. Found: C = 59.56%,
H = 6.90%, N = 14.01%.
Synthesis of 17.
A mixture of benzonitrile (5.17 g,
50.1 mmol), N-methyl-1,3-propanediamine (4.42 g, 50.1 mmol)
and P2S5 (30 mg) was stirred and heated under argon for 4 h at
160 1C before it was evaporated to dryness. The mixture was
treated with dilute aqueous HCl solution until pH 5 was
reached. The solution was then washed twice with CH2Cl2
and the aqueous phase was recovered and evaporated to
dryness. The brownish oil thus obtained was taken up in
EtOH (50 ml) and heated under reflux in the presence of
charcoal during 2 h. After filtration and evaporation, 17 was
obtained in 70% yield as a colourless oil, dried under 60 1C.
Mp 160 1C (decomposition at 100 1C). 1H NMR (D2O +
3
tBuOH, d ppm): 2.17 (q, 2H, J = 5.7 Hz, CH2(CH2–N)2),
3.04 (s, 3H, CH3–N), 3.51 (t, 2H, 3J = 5.7 Hz, CH2–N–CH3),
3.63 (t, 2H, 3J = 5.7 Hz, CH2–NH), 7.60 (m, 5H, CH
arom); 13C NMR (D2O
+
tBuOH,
d ppm): 19.4
(N–CH2–CH2–CH2–N), 39.3, 41.1 (CH2–N), 48.6 (CH3–N),
128.4, 129.8 (CH arom, a and b), 129.4 (C arom), 132.8 (CH
arom, g), 162.4 (N–C–N). Calc. for C11H15ClN2: C = 62.70%,
H = 7.18%, N = 13.30%. Found: C: 62.17%, H 7.07%, N
12.96%.
Synthesis of 15. To a solution of 14 (420 mg, 2.14 mmol) in
distilled water (12 ml) a solution of sodium tetraphenylborate
(804 mg, 2.35 mmol) in CH2Cl2 (25 ml) was added and stirred
vigorously for 3 min. The aqueous phase was extracted with
2 ꢃ 20 ml of CH2Cl2 and the combined organic layers were
washed with 2 ꢃ 15 ml of distilled water, dried over MgSO4,
filtered, evaporated and vacuum dried for 1 day. Compound
25 was obtained as a white solid in 86% yield and was
recrystallised from a CH3Cl–EtOH (13 : 1) mixture, to afford
crystals suitable for X-ray studies. Mp 160 1C (decomposition
Synthesis of 18. Compound 18 is a by-product isolated by
chromatography during the synthesis of 24. Recrystallisation
from a mixture of acetonitrile–ethyl acetate afforded 18 as
colourless crystals, which were analysed by X-ray diffraction
on a single crystal. Mp 177–178 1C (decomposition at 350 1C).
1H NMR (CDCl3, d ppm): 2.18 (q, 2H, 3J = 6.0 Hz,
CH2(CH2–N)2), 3.10 (s, 3H, CH3–N), 3.64 (m, 4H, CH2–NH),
7.48–7.72 (m, 5H, CH arom); 9.24 (NH); 13C NMR (CDCl3, d
ppm): 19.2 (N–CH2–CH2–CH2–N), 38.8, 48.8 (CH2–N), 41.5
(CH3–N), 128.9, 129.3 (CH arom, a and b), 127.8 (C arom),
132.6 (CH arom, g), 161.8 (N–C–N). Calc. for C11H15IN2
C = 43.73%, H = 5.00%, N = 9.27%. Found: C = 43.72%
H = 5.06%, N = 9.28%.
1
at 150 1C). H NMR (CDCl3–CD3OD (2 : 1), d ppm): 2.65 (s,
3H, CH3–N), 3.12 (m, 4H, CH2–N), 6.83 (t, 4H, 3J = 7.2 Hz,
3
CH arom, g (BPh4)), 6.97 (t, 8H, J = 7.2 Hz, CH arom, b
(BPh4)), 7.2–7.4 (m, 10H, CH arom, a and CH arom, a
3
(BPh4)), 7.49 (t, 2H, J = 7.5 Hz, CH arom, b), 7.63 (t, 1H,
3J = 7.5 Hz, CH arom, g); 13C NMR (CDCl3–CD3OD (2 : 1),
d ppm: 34.3 (CH3–N), 42.9, 54.3 (CH2–N), 122.0, 125.8, 136.1
(CH arom, BPh4), 128.4, 129.7 (CH arom, a and b), 127.7
Synthesis of 19. To a solution of 18 (538 mg, 1.78 mmol) in
distilled water (12 ml), a solution of sodium tetraphenylborate
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(670 mg, 1.96 mmol) in CH2Cl2 (25 ml) was added and stirred
vigorously for 3 min. The aqueous phase was extracted with
2 ꢃ 20 ml of CH2Cl2 and the combined organic layers were
washed with 2 ꢃ 15 ml of distilled water, dried over MgSO4,
added. After stirring for 1 h, the mixture was decanted and
the aqueous phase was removed. The colourless liquid was
washed with 2 ꢃ 3 ml of distilled water and dried under
vacuum at 50 1C for 30 h, affording the compound 22 in 91%
yield as a colourless liquid which decomposes at 360 1C.
1H NMR (CDCl3, d ppm): 2.17 (q, 2H, 3J = 5.8 Hz,
CH2(CH2–N)2), 3.06 (s, 3H, CH3–N), 3.54–3.62 (2t, 4H,
filtered and evaporated and vacuum dried for
1 day.
Compound 19 was obtained as a white solid in 96% yield.
Rod-shape colourless crystals of 19 were obtained upon
recrystallisation from
a
CH3Cl–EtOH mixture. Mp
3J
= 5.8 Hz, CH2–N), 7.4–7.6 (m, 5H, CH arom);
204–206 1C (decomposition at 220 1C). 1H NMR (DMSO,
d ppm): 2.02 (q, 2H, 3J = 5.9 Hz, CH2(CH2–N)2), 2.89
(s, 3H, CH3–N), 3.36–3.49 (2t, 4H, 3J = 5.9 Hz, CH2–N),
6.8–7.6 (m, 25H, CH arom); 13C NMR (DMSO, d ppm): 19.0
(N–CH2–CH2–CH2–N), 38.9, 48.1 (CH2–N), 41.0 (CH3–N),
122.0, 125.8, 136.0 (C arom BPh4); 128.6, 129.5 (C arom a and
b); 129.4 (C arom); 132.4 (C arom g); 161.3 (N–C–N);
162.9–163.5–164.2–164.8 (C arom. BPh4). Calc. for
C35H35BN2: C = 85.01%, H = 7.13%, N = 5.67%. Found:
C = 85.31%, H = 6.88%, N = 5.52%.
13C NMR (CDCl3, d ppm): 18.9 (N–CH2–CH2–CH2–N),
39.2, 48.3 (CH2–N), 41.3 (CH3–N), 119.7 (q, CF3, 1J =
319.3 Hz), 127.8, 129.5 (CH arom a and b), 128.0 (C arom),
132.7 (CH arom g), 161.4 (N–C–N). The signal for the C atom
of the anion could not be observed probably due to a too long
relaxation time. Calc. for C13H15F6N3O4S2: C = 34.29%,
H = 3.32%, N = 9.23%. Found: C = 34.58%, H = 3.44%,
N = 9.37%.
Synthesis of 23. 1,4-Dicyanobenzene (3.00 g, 23.4 mmol),
N-methyl-1,3-propanediamine (4.13 g, 46.8 mmol) and P2S5
(10 mg) were mixed and the mixture, under Ar atmosphere,
was stirred and heated to 120 1C during 4 h. After cooling, the
residue was crushed and treated with an aqueous 1 M HCl
solution. After stirring for 30 min, the precipitate was filtered
and the volume of the mother-liquor reduced. Compound 23
was obtained in 66% yield upon recrystallisation from distilled
water. Crystals thus obtained were of sufficient quality for
structural studies by X-ray diffraction on single crystal. Mp
B250 1C (decomposition). 1H NMR (D2O + tBuOH, d ppm):
Synthesis of 20. To a solution of 18 (615 mg, 2.03 mmol) in
distilled water (5 ml) an aqueous solution of ammonium
hexafluorophosphate (663 mg, 4.07 mmol) was added and
stirred for 15 min. The resulting white solid was filtered off,
washed with 3 ꢃ 3 ml of water, then dried under vacuum for
1 day affording 20 as a white solid with a yield of 87%.
Colourless crystals of 20 suitable for X-ray diffraction
analysis, can be obtained by recrystallisation in water. Mp
1
138–141 1C (decomposition at 260 1C). H NMR ((CD3)2O,
d ppm): 2.32 (q, 2H, 3J = 5.9 Hz, CH2(CH2–N)2); 3.17 (s, 3H,
CH3–N); 3.68–3.78 (2t, 4H, 3J = 5.9 Hz, CH2–NH) 7.61–7.75
(m, 5H, CH arom); 8.87 (NH); 13C NMR ((CD3)2O, d ppm):
18.8 (N–CH2–CH2–CH2–N); 39.1 48.1 (CH2–N); 40.6
(CH3–N); 128.0 129.2 (CH arom a et b); 129.3 (C arom);
132.2 (CH arom g); 162.0 (N–C–N). Calc. for C11H15F6N2P:
C = 41.26%, H = 4.72%, N = 8.75%. Found: C = 40.82%,
H = 4.62%, N = 8.80%.
2.20 (q, 4H, J = 5.8 Hz, CH2(CH2–N)2), 3.06 (s, 6H, CH3),
3.54 (t, 4H, 3J = 5.8 Hz, CH2–N–CH3), 3.66 (t, 4H, 3J = 5.8
3
Hz, CH2–NH), 7.77 (s, 4H, CH arom); 13C NMR (D2O +
tBuOH,
d
ppm): 19.2 (N–CH2–CH2–CH2–N), 39.3
(CH2–NH), 41.1 (CH3–N), 48.7 (CH2–N–CH3), 129.5 (CH
arom, 132.8 (C arom), 161.2 (N–C–N). Calc. for C16H24N4Cl2ꢂ
4.7H2O: C = 44.90%, H = 7.87%, N = 13.09%. Found
C = 44.81%, H = 7.82%, N = 13.43%.
Synthesis of 21. A solution of 2 (1.00 g, 5.74 mmol) in
distilled water (3 ml) was cooled to 0 1C and then an aqueous
solution (4 ml) containing trifluoromethanesulfonic acid
(861 mg, 5.74 mmol) was added. After stirring for 1 h, the
solvent was removed affording the compound 21 as a white
solid with in 99% yield. Colourless crystals were be obtained
upon diffusing diethyl ether vapours into an EtOH solution of
21 and studied by X-ray diffraction on single crystal. Mp 76 1C
(decomposition at 350 1C). 1H NMR (CDCl3, d ppm): 2.13
Synthesis of 24. A mixture of 1 (600 mg, 3.74 mmol),
1-iodopropane (1.27 g, 7.49 mmol) and K2CO3 (517 mg,
3.74 mmol) in DMF (30 ml) was stirred at RT overnight.
The solvent was removed and the residue was purified by
chromatography (Al2O3, CH2Cl2–MeOH (97 : 3 - 96 : 4)).
Compound 24, a colourless and very hygroscopic viscous
liquid, was dried at 50 1C under vacuum for 12 h was obtained
in 83% yield. The latter decomposed at 280 1C. 1H NMR
3
(CDCl3, d ppm): 0.80 (t, 3H, J = 7.4 Hz, CH3 propyl), 1.61
3
3
(q, 2H, J = 6.0 Hz, CH2(CH2–N)2), 3.06 (s, 3H, CH3–N),
3.51–3.60 (2t, 4H, 3J = 6.0 Hz, CH2–N), 7.4–7.6 (m, 5H,
(sex, 2H, J = 7.4 Hz, CH2–CH3), 2.98 (s, 3H, CH3–N), 3.20
(t, 2H, 3J = 7.4 Hz, C2H5–CH2–N), 4.25 (m, 4H, CH2–N)
7.5–7.7 (m, 5H, CH arom); 13C NMR (CDCl3, d ppm): 11.1
(CH3 propyl), 20.5 (CH2–CH3), 35.1 (CH3–N), 48.2, 49.7, 50.9
(CH2–N), 122.0 (C arom), 128.8, 129.8 (CH arom, a and b),
132.7 (CH arom, g), 166.4 (N–C–N). Calc. for C13H19N2I:
C = 47.29%, H = 5.80%, N = 8.48%. Found: C = 47.05%,
H = 6.18%, N = 8.06%.
CH arom); 13C NMR (CDCl3,
d
ppm): 19.1
(N–CH2–CH2–CH2–N), 39.0 48.4 (CH2–N), 41.2 (CH3–N),
128.1, 129.3 (CH arom a and b), 128.0 (C arom, 132.5 (CH
arom g), 162.2 (N–C–N). The signal for the C atom of the
triflate anion could not be observed probably due to a too long
relaxation time. Calc. for C12H15F3N2O3S: C = 44.44%,
H = 4.66%, N = 8.64%. Found: C = 44.00%, H = 4.70%,
N = 8.40%.
Synthesis of 25. To a solution of 24 (212 mg, 0.64 mmol) in
distilled water (12 ml) a solution of sodium tetraphenylborate
(242 mg, 0.71 mmol) in CH2Cl2 (25 ml) was added and stirred
vigorously for 3 min. The aqueous phase was extracted with
2 ꢃ 20 ml of CH2Cl2 and the combined organic layers were
Synthesis of 22. To a solution of 18 (684 mg, 2.26 mmol) in
distilled water (5 ml) an aqueous solution (3 ml) of lithium
bis(trifluoromethane)sulfonimide (670 mg, 2.26 mmol) was
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washed with 2 ꢃ 15 ml of distilled water, dried over MgSO4,
filtered, evaporated and vacuum dried for 1 day. Compound
24 was obtained as a white solid in 74% yield which was
recrystallised from a EtOH–CH2Cl2 mixture, affording suitable
crystals for X-Ray diffraction. Mp 162 1C (decomposition at
160 1C). 1H NMR (CD2Cl2, d ppm): 0.76 (t, 3H, 3J = 7.5 Hz,
CH3 propyl), 1.44 (sex, 2H, 3J = 7.5 Hz, 2H, CH2–CH3), 2.61
(s, 3H, CH3–N), 2.95 (t, 2H, 3J = 7.5 Hz, C2H5–CH2–N), 3.22
(m, 4H, CH2–N), 6.89 (t, 4H, 3J = 7.1 Hz, CH arom,
g (BPh4)), 7.04 (t, 8H, 3J = 7.2 Hz, CH arom, b (BPh4)),
7.23 (d, 2H, 3J = 7.2 Hz, CH arom, a), 7.38 (br, 8H, CH
in EtOH, 28 can be obtained either as colourless plate shaped
crystals with a yield of 48%, or as an oil which solidifies after
several days. Mp 114 1C (decomposition at 100 1C). 1H NMR
((CDCl3, d ppm): 0.84 (t, 3H, 3J = 7.2 Hz, CH3 hexyl), 1.0–1.4
(m, 8H, (CH2)3–CH3), 2.48 (s, 3H, CH3–N), 2.9 (m, 6H,
3
CH2–N), 6.90 (t, 4H, J = 7.1 Hz, CH arom g (BPh4)), 7.06
(t, 8H, 3J = 7.2 Hz, CH arom b (BPh4)), 7.18 (d, 2H, 3J = 7.2 Hz,
CH arom a), 7.49 (br, 8H, CH arom a (BPh4)), 7.61 (t, 2H,
3J = 7.2 Hz, CH arom b), 7.69 (t, 1H, 3J = 7.2 Hz, CH arom g);
13C NMR (CDCl3, d ppm): 14.1 (CH3 hexyl), 22.6, 26.1, 27.3,
31.2 (CH3–(CH2)4–CH2N), 34.7 (CH3–N), 47.9, 48.0
(CH2–N), 51.3 (C5H11–CH2–N), 122.1, 125.9, 136.4 (CH arom
BPh4), 128.1, 130.3 (CH arom a and b), 128.9 (C arom), 133.3
(CH arom g). Calc. for C40H45BN2: C = 85.09%, H = 8.03%,
N = 4.96%. Found: C = 85.55%, H = 8.05%, N = 4.89%.
3
arom, a (BPh4)), 7.63 (t, 2H, J = 7.2 Hz, CH arom, b), 7.71
(t, 1H, 3J = 7.2 Hz, CH arom, g); 13C NMR (CDCl3, d ppm):
12.4 (CH3 propyl), 22.4 (CH2–CH3), 36.3 (CH3–N), 49.2, 51.2,
51.7 (CH2–N), 123.0 (C arom), 123.7, 127.6, 137.8 (CH arom
BPh4), 129.6, 132.1 (CH arom, a and b), 135.3 (CH arom, g),
164.9, 165.6, 166.2, 166.9, 168.4 (C arom, BPh4 and N–C–N).
Calc. for C37H39BN2: C = 85.05%, H = 7.52%, N = 5.39%.
Found: C = 85.45%, H = 7.53%, N = 5.02%.
Synthesis of 29. The same procedure described for 26 was
used, starting from 27 (120 mg, 0.369 mmol) and ammonium
hexafluorophosphate (66 mg, 0.406 mmol). 29 was obtained as
a viscous colourless liquid, that decomposes at 250 1C) with a
71% yield. 1H NMR ((CDCl3, d ppm): 0.80 (t, 3H, 3J = 7.2 Hz,
CH3 hexyl), 1.1–1.3 (m, 6H, (CH2)3–CH3), 1.54 (m, 2H,
Synthesis of 26. To a solution of 24 (301 mg, 0.91 mmol) in
of distilled water (5 ml) an aqueous solution (5 ml) of
ammonium hexafluorophosphate (208 mg, 1.28 mmol) was
added and the mixture stirred for 15 min. The white solid thus
formed was filtered off, washed with water (3 ꢃ 3 ml) and
dried under vacuum for 1 day affording the compound 16 as a
white solid in 82% yield. For X-ray diffraction analysis,
suitable colourless crystals were obtained upon slow diffusion
of acetone into a water–acetone mixture containing 16. Mp
62–64 1C (decomposition at 300 1C). 1H NMR (CDCl3,
d ppm): 0.80 (t, 3H, 3J = 7.4 Hz, CH3 propyl), 1.60 (sex, 2H,
3J = 7.4 Hz, CH2–CH3), 2.92 (s, 3H, CH3–N), 3.15 (t, 2H,
3J = 7.4 Hz, C2H5–CH2–N), 4.11 (m, 4H, CH2–N), 7.5–7.7
(m, 5H, CH arom); 13C NMR (CDCl3, d ppm): 10.8 (CH3
propyl), 20.3 (CH2–CH3), 34.3 (CH3–N), 47.6, 49.4, 50.1
(CH2–N), 122.1 (C arom), 128.1, 129.9 (CH arom, a and b),
132.7 (CH arom, g), 166.2 (N–C–N). Calc. for C13H19F6N2P:
C = 44.83%, H = 5.50%, N = 8.04%. Found: C = 44.69%,
H = 5.22%, N = 8.12%.
3
CH2–CH2N), 2.93 (s, 3H, CH3–N), 3.18 (t, 2H, J = 7.5 Hz,
C5H11–CH2–N), 4.11 (m, 4H, CH2–N), 7.4–7.7 (m, 5H, CH
arom); 13C NMR (CDCl3, d ppm): 14.1 (CH3 hexyl), 22.5,
26.1, 27.1, 31.2 (CH3–(CH2)4–CH2N), 34.5 (CH3–N), 47.9,
48.0 (CH2–N);, 50.3 (C5H11–CH2–N), 122.3 (C arom), 128.3,
130.0 (CH arom a and b), 132.9 (CH arom g), 166.4 (N–C–N).
Calc. for C13H19F6N2P: C = 44.83%, H = 5.50%, N = 8.04%.
Found: C = 44.69%, H = 5.22%, N = 8.12%.
Synthesis of 30. The same procedure described for 27 was
used, starting from 14 (619 mg, 3.87 mmol) and 1-bromo-
dodecane (1.93 g, 7.73 mmol) as well as K2CO3 (534 mg,
3.87 mmol). 30 was obtained as a colourless hygroscopic
viscous liquid with a yield of 60%. Mp not determined, liquid
at room temperature (decomposition at 240 1C). 1H NMR
((CDCl3, d ppm): 0.83 (t, 3H, 3J = 7.2 Hz, CH3 dodecyl),
1.0–1.3 (m, 18H, (CH2)9–CH3), 1.53 (m, 2H, CH2–CH2N),
2.99 (s, 3H, CH3–N), 3.24 (t, 2H, 3J
= 7.8 Hz,
Synthesis of 27. The same procedure described for 24 was
used, using 14 (600 mg, 3.75 mmol) and 1-bromohexane
(1.24 g, 7.40 mmol), as well as K2CO3 (501 mg, 3.75 mmol).
27 was obtained as a colourless hygroscopic viscous liquid
with a yield of 51%. Mp not determined, liquid at room
C11H23–CH2–N), 4.25 (m, 4H, CH2–N), 7.4–7.7 (m, 5H, CH
arom); 13C NMR (CDCl3, d ppm): 14.1 (CH3 dodecyl), 22.6,
26.3, 27.1, 28.8, 29.1, 29.3, 29.3, 29.4, 29.5, 31.8 (CH2
n-dodecyl), 34.9 (CH3–N), 48.1, 48.3, 50.9 (CH2–N), 122.1
(C arom), 128.4, 128.8 (CH arom a and b), 132.7 (CH arom g),
166.4 (N–C–N).
1
temperature (decomposition at 120 1C). H NMR ((CD3)2O,
d ppm): 0.80 (t, 3H, 3J = 7.2 Hz, CH3 hexyl), 1.0–1.4 (m, 6H,
(CH2)3CH3), 1.55 (m, 2H, CH2–CH2N), 3.00 (s, 3H, CH3–N),
3.26 (t, 2H, 3J = 7.5 Hz, C5H11–CH2–N), 4.27 (m, 4H,
CH2–N), 7.4–7.7 (m, 5H, CH arom); 13C NMR (CDCl3,
Synthesis of 31. The same procedure described for 25 was
used, starting from 30 (196 mg, 0.339 mmol) and sodium
tetraphenylborate (139 mg, 0.407 mmol). After recrystallisation
in EtOH, 31 can be obtained either as colourless prismatic
crystals with a yield of 60%, or as an oil which solidifies after
d
ppm): 14.1 (CH3 hexyl), 22.6, 26.2, 27.2, 31.2
(CH3–(CH2)4–CH2N), 35.1 (CH3–N), 48.3, 48.5 (CH2–N),
51.0 (C5H11–CH2–N), 122.3 (C arom), 128.7 129.9 (CH arom
a and b), 132.8 (CH arom g), 166.7 (N–C–N). Calc. for
C16H25BrN2ꢂ1/2H2O: C = 57.49%, H = 7.84%, N = 8.38%.
Found: C = 57.50%, H = 8.45%, N = 8.44%.
1
several days. Mp 69 1C (decomposition at 220 1C). H NMR
((CDCl3, d ppm): 0.88 (t, 3H, 3J = 6.6 Hz, CH3 dodecyl),
1.0–1.3 (m, 20H, (CH2)10–CH3), 2.43 (s, 3H, CH3–N), 2.8 (m,
3
6H, CH2–N), 6.90 (t, 4H, J = 7.1 Hz, CH arom g (BPh4)),
3
7.05 (t, 8H, J = 7.2 Hz, CH arom b (BPh4)), 7.15 (d, 2H,
Synthesis of 28. The same procedure described for 25 was
used, starting from 27 (55 mg, 0.169 mmol) and sodium
tetraphenylborate (64 mg, 0.186 mmol). After recrystallisation
3J = 7.2 Hz, CH arom a), 7.49 (br, 8H, CH arom a (BPh4)),
7.60 (t, 2H, 3J = 7.2 Hz, CH arom b), 7.69 (t, 1H, 3J = 7.2 Hz,
CH arom g); 13C NMR (CDCl3, d ppm): 14.1 (CH3 dodecyl),
ꢁc
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1192 | New J. Chem., 2010, 34, 1184–1199

View Article Online
22.7, 26.3, 27.1, 28.9, 29.3, 29.5, 29.6, 31.9 (CH2 dodecyl), 34.6
(CH3–N), 47.3, 47.6, 49.7 (CH2–N), 121.8, 125.7, 136.1 (CH
arom BPh4), 125.7, 130.2 (CH arom a and b), 127.7 (C arom),
133.2 (CH arom g). Calc. for C46H57BN2: C = 85.16%,
H = 8.86%, N = 4.32%. Found: C = 85.42%, H = 9.14%,
N = 4.12%.
C38H41BN2: C 85.06%, H 7.70%, N 5.22%. Found: C
85.26%, H 7.71%, N 5.17%.
Synthesis of 35. For the synthesis of 35, the procedure
described for 20 was followed using 33 (1.31 g, 3.82 mmol)
and ammonium hexafluorophosphate (1.24 g, 7.63 mmol).
Compound 35 was obtained as a white powder in 97% yield
and was recrystallised either from water or a water–acetone
mixture. Mp 93 1C (decomposition at 300 1C). 1H NMR
(CDCl3, d ppm): 0.70 (t, 3H, 3J = 7.4 Hz, CH3 propyl),
1.54 (m, 2H, CH2–CH3), 2.29 (q, 2H, 3J = 6.0 Hz,
Synthesis of 32. The same procedure described for 26 was
used, starting from 30 (215 mg, 0.525 mmol) and ammonium
hexafluorophosphate (120 mg, 0.735 mmol). 32 was obtained
as a viscous colourless liquid, that decomposes at 50 1C, with a
79% yield. 1H NMR (CDCl3, d ppm): 0.86 (t, 3H, 3J =
7.2 Hz, CH3 dodecyl), 1.0–1.3 (m, 18H, (CH2)9–CH3), 1.54
3
CH2(CH2–N)2), 2.87 (s, 3H, CH3–N), 3.05 (t, 2H, J = 7.7 Hz,
C2H5–CH2–N), 3.64 (2t, 4H, 3J = 6.0 Hz, CH2–N) 7.4–7.6
3
3
4
5
(m, 2H, CH2–CH2N), 2.93 (s, 3H, CH3–N), 3.18 (t, 2H, J =
(m, 5H, CH arom, J = 50 Hz, J = 6.0 Hz, J = 1.4 Hz);
13C NMR (CDCl3,
ppm): 10.8 (CH3 propyl), 18.9
7.5 Hz, C11H23–CH2–N), 4.10 (m, 4H, CH2–N), 7.5–7.8 (m,
5H, CH arom); 3C NMR (CDCl3, d ppm): 14.1 (CH3 dodecyl),
22.7, 26.3, 27.0, 28.9, 29.3, 29.5, 29.6, 29.6, 31.9 (CH2
n-dodecyl), 34.3 (CH3–N), 47.7, 47.8, 50.1 (CH2–N), 122.1
(C arom), 128.1, 129.8 (CH arom a and b), 132.7 (CH arom g),
166.2 (N–C–N). Calc. for C22H37F6N2P: C = 55.69%,
H = 7.86%, N = 5.90%. Found: C = 56.93%, H = 8.30%,
N = 5.32%.
d
(N–CH2–CH2–CH2–N), 20.9 (CH2–CH3), 42.0 (CH3–N),
45.1 48.0 (CH2–N), 55.8 (C2H5–CH2–N), 127.1, 130.0 (CH
arom, a and b), 128.1 (C arom); 131.6 (CH arom, g), 162.3
(N–C–N). Calc. for C14H21F6N2P: C = 46.41%, H = 5.84%,
N = 7.73%. Found: C = 45.82%, H = 5.86%, N = 7.77%.
Synthesis of 36. 33 (1.20 g, 3.49 mmol) was dissolved in 7 ml
of distilled water and 8 ml of an aqueous solution containing
lithium triflate (598 mg, 3.83 mmol) was added. After stirring
for 1 h, the mixture was extracted with 3 ꢃ 15 ml of CH2Cl2.
The combined organic layers was washed with 8 ml of water
and dried over MgSO4, filtered and evaporated to dryness.
The resulting colourless oil was further dried under vacuum at
40 1C for 30 h. Compound 36 was obtained in 93% yield as a
colourless liquid which decomposes at 220 1C. 1H NMR
(CDCl3, d ppm): 0.68 (t, 3H, 3J = 7.4 Hz, CH3 propyl),
1.54 (m, 2H, CH2–CH3), 2.31 (q, 2H, 3J = 6.0 Hz,
Synthesis of 33. A mixture of 17 (5.00 g, 27.7 mmol) and
1-iodopropane (4.88 g, 27.7 mmol) in DMF (30 ml) was stirred
for 3 h at RT. The volatiles were removed by evaporation and
the residue was purified by chromatography (Al2O3,
CH2Cl2–MeOH (98 : 2)). The yellow oil thus obtained was
taken up in MeOH (40 ml) and after addition of charcoal, the
mixture was heated under reflux overnight. After filtration and
evaporation, the resulting colourless oil was dried under
vacuum affording 33 in 55% yield as a rather hygroscopic
yellowish powder. Mp 88 1C (decomposition at 200 1C).
1H NMR (CDCl3, d ppm): 0.55 (t, 3H, 3J = 7.4 Hz, CH3
3
CH2(CH2–N)2), 2.87 (s, 3H, CH3–N), 3.05 (t, 2H, J = 7.8 Hz,
3
C2H5–CH2–N), 3.73 (2t, 4H, J = 6.0 Hz, CH2–N), 7.55 (m,
3
propyl), 1.45 (m, 2H, CH2–CH3), 2.26 (q, 2H, J = 6.0 Hz,
5H, CH arom); 13C NMR (CDCl3, d ppm): 10.8 (CH3 propyl),
19.3 (N–CH2–CH2–CH2–N), 21.0 (CH2–CH3), 42.3 (CH3–N),
45.3, 48.3 (CH2–N), 55.9 (C2H5–CH2–N), 127.5, 129.9 (CH
arom, a and b), 128.2 (C arom, 131.6 (CH arom, g), 162.4
(N–C–N). The signal for the C atom of the triflate anion could
not be observed probably due to a too long relaxation time.
Calc. for C15H21F3N2O3S: C = 49.17%, H = 5.78%,
N = 7.65%. Found: C = 48.66%, H = 6.26%, N = 7.69%.
CH2(CH2–N)2), 2.78 (s, 3H, CH3–N), 2.95 (t, 2H, 3J = 7.5 Hz,
C2H5–CH2–N), 3.68 3.70 (2t, 4H, 3J = 6.0 Hz, CH2–N),
7.25–7.61 (m, 5H, CH arom); 13C NMR (D2O + tBuOH,
d ppm): 10.9 (CH3 propyl), 19.4 (N–CH2–CH2–CH2–N), 21.0
(CH2–CH3), 42.7 (CH3–N), 45.4, 48.4 (CH2–N), 56.0
(C2H5–CH2–N), 127.7, 129.7 (CH arom, a and b), 128.1
(C arom), 131.5 (CH arom, g), 162.1 (N–C–N). Calc. for
C14H21N2I: C = 48.85%, H = 6.15%, N = 8.14%. Found:
C = 48.21%, H = 6.14%, N = 8.14%.
Synthesis of 37. The same procedure described for 22 was
followed, using 33 (687 mg, 2.87 mmol) and lithium bis-
(trifluoromethane)sulfonimide (866 mg, 2.87 mmol). Compound
37 was obtained in 98% yield as a colourless liquid which
decomposes at 210 1C. 1H NMR (CDCl3, d ppm): 0.66 (t, 3H,
3J = 7.2 Hz, CH3 propyl), 1.51 (m, 2H, CH2–CH3), 2.23
Synthesis of 34. For preparing 34, the procedure described
for the synthesis of 19 was employed using 33 (0.935 g,
2.72 mmol) and sodium tetraphenylborate (1.02 g, 2.99 mmol).
After recrystallisation in ethanol, 34 was obtained in 85%
yield as rod shaped colourless crystals suitable for X-ray
diffraction studies. Mp 119–120 1C (decomposition at 200 1C).
1H NMR (CDCl3, d ppm): 0.61 (t, 3H, 3J = 7.4 Hz, CH3
3
(q, 2H, J = 6.2 Hz, CH2(CH2–N)2), 2.81 (s, 3H, CH3–N),
3.01 (t, 2H, 3J = 7.8 Hz, C2H5–CH2–N), 3.59 (2t, 4H, 3J = 6.2
Hz, CH2–N), 7.3–7.6 (m, 5H, CH arom); 13C NMR (CDCl3,
d ppm): 10.6 (CH3 propyl), 18.8 (N–CH2–CH2–CH2–N), 20.8
(CH2–CH3), 41.9 (CH3–N), 45.2, 48.0 (CH2–N), 55.8
3
propyl), 1.26 (m, 2H, CH2–CH3), 1.39 (q, 2H, J = 5.9 Hz,
CH2(CH2–N)2), 2.27 (s, 3H, CH3–N), 2.60 (m, 6H, CH2–N),
6.8–7.6 (m, 25H, CH arom); 13C NMR (CDCl3, d ppm): 10.7
(CH3 propyl), 18.6 (N–CH2–CH2–CH2–N), 21.0 (CH2–CH3),
41.7 (CH3–N); 44.8, 47.7 (CH2–N), 55.5 (C2H5–CH2–N),
121.9, 125.6, 136.2 (CH arom BPh4), 126.6, 130.2 (CH arom,
a and b), 126.6 (C arom, 132.0 (CH arom, g), 161.5 (N–C–N),
163.1, 163.7, 164.4, 165.0 (C arom BPh4). Calc. for
1
(C2H5–CH2–N), 119.9 (q, CF3, J = 321.6 Hz), 127.0, 129.9
(CH arom, a and b), 128.0 (C arom); 131.7 (CH arom, g),
162.3 (N–C–N). Probably, owing to a too long relaxation
time, no 13C signal was observed for the anion. Calc. for
C16H21F6N3O4S2: C = 38.63%, H = 4.25%, N = 8.45%.
Found: C = 38.70%, H = 4.26%, N = 8.45%.
ꢁc
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Synthesis of 38. 2 (520 mg, 2.99 mmol), 1-bromohexane
(987 mg, 5.98 mmol) and K2CO3 (412 mg, 2.99 mmol) were
dissolved in 30 ml DMF and stirred overnight at RT. The
solvents were then evaporated to dryness and the residue was
purified by chromatography (Al2O3, CH2Cl2–MeOH (97 : 3 -
96 : 4)). The corresponding phases were evaporated affording a
colourless oil which was dried at 50 1C under vacuum for 12 h.
38 was obtained as a very hygroscopic viscous liquid that
decomposes at 150 1C, with a yield of 63%. 1H NMR (CDCl3,
d ppm): 0.66 (t, 3H, 3J = 7.2 Hz, CH3 hexyl), 0.8–1.3 (m, 6H,
(CH2)3–CH3), 1.42 (m, 2H, CH2–CH2N), 2.27 (q, 2H, 3J = 6.0 Hz,
CH2(CH2–N)2), 2.83 (s, 3H, CH3–N), 3.00 (t, 2H, 3J = 7.9 Hz,
d ppm): 0.73 (t, 3H, 3J = 7.4 Hz, CH3 hexyl), 0.9–1.5 (m, 6H,
(CH2)3–CH3), 1.45 (m, 2H, CH2–CH2N), 2.25 (q, 2H, J =
3
6.0 Hz, CH2(CH2–N)2), 2.83 (s, 3H, CH3–N), 3.02 (t, 2H, 3J =
3
7.9 Hz, C5H11–CH2–N), 3.64 (2t, 4H, J = 6.0 Hz, CH2–N),
7.4–7.6 (m, 5H, CH arom), 13C NMR (CDCl3, d ppm): 13.8
(CH3 hexyl), 19.0 (N–CH2–CH2–CH2–N), 22.2, 25.8, 27.4,
30.8 (CH3–(CH2)4–CH2N), 42.0 (CH3–N), 45.2, 48.1
(CH2–N), 54.3 (C5H11–CH2–N), 127.2, 129.9 (CH arom a
and b), 128.2 (C arom), 131.6 (CH arom g), 162.2 (N–C–N).
Probably, owing to a too long relaxation time, no 13C signal
was observed for the anion. Calc. for C18H27F3N2O3S:
C = 52.93%, H = 6.66%, N = 6.86%. Found: C =
53.82%, H = 6.41%, N = 7.90%.
3
C5H11–CH2–N), 3.73 (2t, 4H, J = 6.0 Hz, CH2–N), 7.4–7.6
(m, 5H, CH arom); 13C NMR (CDCl3, d ppm): 13.8 (CH3
hexyl), 19.4 (N–CH2–CH2–CH2–N), 22.2, 25.8, 27.5, 30.8
(CH3–(CH2)4–CH2N), 42.4 (CH3–N), 45.5, 48.5 (CH2–N),
54.4 (C5H11–CH2–N), 127.4, 129.7 (CH arom a and b),
128.2 (C arom), 131.5 (CH arom g), 162.1 (N–C–N). Calc.
Synthesis of 42. The same procedure described for 22 was
used, starting from 38 (827 mg, 2.44 mmol) and lithium
bis(trifluoromethane)sulfonimide (770 mg, 2.68 mmol). 42
was obtained as a colourless liquid, that decomposes at
350 1C, with a 97% yield. 1H NMR (CDCl3, d ppm): 0.77
for C17H27BrN2ꢂ2/3H2O:
C = 58.12%, H = 8.13%,
(t, 3H, 3J
= 7.2 Hz, CH3 hexyl), 0.9–1.2 (m, 6H,
3
N = 7.97%. Found: C = 58.13%, H = 8.15%, N = 8.00%.
(CH2)3–CH3), 1.49 (m, 2H, CH2–CH2N), 2.26 (q, 2H, J =
6.0 Hz, CH2(CH2–N)2), 2.84 (s, 3H, CH3–N), 3.01 (t, 2H, 3J =
Synthesis of 39. The same procedure described for 19 was
used, starting from 38 (1.00 g, 2.95 mmol) and sodium tetra-
phenylborate (1.11 g, 3.24 mmol). After recrystallisation in a
mixture of EtOH–CHCl3, colourless crystals of 39 were obtained
in 91% yield. Mp 94–95 1C (decomposition at 250 1C). 1H NMR
3
7.9 Hz, C5H11–CH2–N), 3.63 (2t, 4H, J = 6.0 Hz, CH2–N),
7.4–7.7 (m, 5H, CH arom); 13C NMR (CDCl3, d ppm): 13.8
(CH3 hexyl), 18.9 (N–CH2–CH2–CH2–N), 22.2, 25.8, 27.4,
30.8 (CH3–(CH2)4–CH2N), 42.0 (CH3–N), 45.2, 48.0
(CH2–N), 54.4 (C5H11–CH2–N), 119.9 (q, CF3), 127.0 130.0
(CH arom a and b), 128.0 (C arom), 131.7 (CH arom g), 162.3
(N–C–N). Probably, owing to a too long relaxation time, no
13C signal was observed for the anion. Calc. for
C19H27F6N3O4S2: C = 42.29%, H = 5.04%, N = 7.79%.
Found: C = 42.51%, H = 5.09%, N = 7.61%.
3
(CDCl3, d ppm): 0.83 (t, 3H, J = 7.2 Hz, CH3 hexyl), 0.9–1.4
(m, 8H, (CH2)4–CH3), 2.24 (s, 3H, CH3–N), 2.60 (m, 6H,
CH2–N) 6.8–7.6 (m, 25H, CH arom), 13C NMR (CDCl3,
d ppm): 13.9 (CH3 hexyl), 18.6 (N–CH2–CH2–CH2–N), 22.3,
25.7, 27.5, 30.9 (CH3–(CH2)4–CH2N), 41.7 (CH3–N), 44.8, 47.6
(CH2–N), 54.0 (C5H11–CH2–N), 121.9, 125.6, 136.2 (CH arom
BPh4), 126.6, 130.2 (CH arom a and b), 127.3 (C arom), 132.0
(CH arom g), 161.3 (N–C–N), 163.1, 163.7, 164.4, 165.0 (C arom
BPh4). Calc. for C41H47BN2: C = 85.10%, H = 8.19%,
N = 4.84%. Found: C = 85.23%, H = 8.38%, N = 4.66%.
Synthesis of 43. The same procedure described for 38 was
used, starting from 17 (4.37 g, 25.1 mmol) and 1-bromododecane
(2.49 g, 50.1 mmol), as well as K2CO3 (3.46 g, 25.1 mmol). 43
was obtained as a colourless hygroscopic viscous liquid which
solidified in a fridge after several days. Yield = 87%. Mp
B49 1C (decomposition at 200 1C). 1H NMR (CDCl3, d ppm):
0.83 (t, 3H, 3J = 7.2 Hz, CH3 dodecyl), 0.9–1.4 (m, 20H,
Synthesis of 40. The same procedure described for 20 was
used, starting from 38 (671 mg, 1.98 mmol) and ammonium
hexafluorophosphate (354 mg, 2.17 mmol). 40 was obtained as a
viscous colourless liquid with a 92% yield. This liquid solidified
after several days. Mp 41–47 1C (decomposition at 220 1C).
1H NMR (CDCl3, d ppm): 0.77 (t, 3H, 3J = 7.2 Hz, CH3 hexyl),
0.9–1.2 (m, 6H, (CH2)3–CH3), 1.50 (m, 2H, CH2–CH2N), 2.28
(q, 2H, 3J = 6.0 Hz, CH2(CH2–N)2), 2.86 (s, 3H, CH3–N), 3.06
(t, 2H, 3J = 7.9 Hz, C5H11–CH2–N), 3.63 (2t, 4H, 3J = 6.0 Hz,
CH2–N), 7.4–7.6 (m, 5H, CH arom); 13C NMR (CDCl3, d ppm):
13.8 (CH3 hexyl), 18.9 (N–CH2–CH2–CH2–N), 22.2, 25.8, 27.3,
30.8 (CH3–(CH2)4–CH2N), 41.9 (CH3–N), 45.2, 48.0 (CH2–N),
54.3 (C5H11–CH2–N), 127.1, 129.9 (CH arom a and b), 128.2
(C arom), 131.6 (CH arom g), 162.2 (N–C–N). Calc. for
C17H27F6N2P: C = 50.49%, H = 6.73%, N = 6.93%. Found:
C = 50.54%, H = 6.80%, N = 6.60%.
3
(CH2)10–CH3), 1.49 (m, 2H, CH2–CH2N), 2.34 (q, 2H, J =
6.0 Hz, CH2(CH2–N)2), 2.90 (s, 3H, CH3–N); 3.08 (t, 2H, 3J =
3
7.9 Hz, C5H11–CH2–N), 3.81 (2t, 4H, J = 6.0 Hz, CH2–N),
7.4–7.7 (m, 5H, CH arom); 13C NMR (CDCl3, d ppm): 14.0
(CH3 dodecyl), 19.4 (N–CH2–CH2–CH2–N), 22.6, 26.1, 27.5,
28.6, 29.1, 29.2, 29.3, 29.4, 29.5, 31.8 (CH3–(CH2)10–CH2N),
42.4 (CH3–N), 45.5–48.5 (CH2–N), 54.4 (C11H23–CH2–N),
127.4, 129.7 (CH arom a and b), 128.2 (C arom), 131.5 (CH
arom g) 162.1 (N–C–N). Calc. for C23H39BrN2ꢂH2O:
C = 62.57%, H = 9.36%, N = 6.35%. Found: C =
62.54%, H = 9.65%, N = 6.16%.
Synthesis of 44. The same procedure described for 19 was
used, starting from 43 (494 mg, 1.17 mmol) and sodium
tetraphenylborate (439 mg (1.28 mmol). The crude product
was redissolved in 40 ml of a mixture of EtOH–CHCl3 (1 : 1)
affording 43 as a white solid after slow evaporation of CHCl3.
Synthesis of 41. The same procedure described for 36 was
used, starting from 38 (1.00 g, 2.95 mmol) and lithium triflate
(506 mg, 3.24 mmol), affording 41 as a colourless oil, that
1
Mp 91–93 1C (decomposition at 250 1C). H NMR (CDCl3,
3
d ppm): 0.90 (t, 3H, J = 6.8 Hz, CH3 dodecyl), 1.0–1.4 (m,
20H, (CH2)10–CH3), 2.25 (s, 3H, CH3–N), 2.60 (m, 6H,
1
decomposes at 230 1C, with a 92% yield. H NMR (CDCl3,
ꢁc
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CH2–N) 6.8–7.6 (m, 25H, CH arom); 13C NMR (CDCl3, d
ppm): 14.2 (CH3 dodecyl), 18.6 (N–CH2–CH2–CH2–N), 22.7,
26.0, 27.6, 28.8, 29.3, 29.3, 29.4, 29.6, 29.6, 31.9
(CH3–(CH2)10–CH2N), 41.7 (CH3–N), 44.8, 47.6 (CH2–N),
54.0 (C11H23–CH2–N), 121.9, 125.6, 136.2 (CH arom BPh4),
126.6, 130.2 (CH arom a and b), 127.3 (C arom), 132.0 (CH
arom g), 161.3 (N–C–N), 163.1 163.7, 164.4, 165.0 (C arom
BPh4). Calc. for C47H59BN2: C = 85.17%, H = 8.97%,
N = 4.23%. Found: C = 85.92%, H = 9.06%, N = 4.00%.
119.9 (q, CF3), 127.0 130.0 (CH arom a and b), 128.0 (C
arom), 131.7 (CH arom g), 162.3 (N–C–N). Probably, owing
to a too long relaxation time, no 13C signal was observed for
the anion. Calc. for C25H39F6N3O4S2: C 48.14%, H 6.30%, N
6.74%. Found: C 48.57%, H 6.13%, N 6.38%.
Synthesis of 48. 3 (1.0 g, 3.7 mmol) and 1-iodopropane
(1.26 g, 7.4 mmol) of were dissolved in 40 ml of dry DMF and
the mixture was heated at 70 1C overnight under argon. After
cooling, the white solid was filtered off, washed with 2 ꢃ 15 ml
of diethyl ether, then dried under vacuum. The compound was
recrystallised from distilled water to afford colourless crystals
of 48, suitable for X-ray diffraction (yield 79%). Mp >340 1C.
1H NMR (D2O + tBuOH, d ppm): 0.68, 0.69 (2t, 6H, 3J = 7.2
Synthesis of 45. The same procedure described for 20 was
used, starting from 43 (809 mg, 1.91 mmol) and ammonium
hexafluorophosphate (343 mg, 2.10 mmol). 45 was obtained as
a viscous colourless liquid with a 96% yield. Mp 49–51 1C
(decomposition at 200 1C). 1H NMR (CDCl3, d ppm): 0.86 (t,
3
Hz, CH3 propyl), 1.57 (m, 4H, CH2–CH3), 2.25 (q, 4H, J =
3H, 3J
=
6.9 Hz, CH3 dodecyl), 0.9–1.3 (m, 18H,
3
5.8 Hz, CH2(CH2–N)2), 2.87, 2.90 (2s, 6H, CH3–N), 3.09, 3.11
(2t, 4H, 3J = 7.8 Hz, C2H5–CH2–N), 3.64, 3.66 (2t, 8H,
3J = 5.8 Hz, CH2–N) 7.80, 7.81 (2s, 4H, CH arom);
13C NMR (D2O + tBuOH, d ppm): 10.6, 10.7 (CH3), 19.3
(N–CH2–CH2–CH2–N), 21.0, 21.1 (CH2–CH3), 42.2
(CH3–N), 45.9, 46.0 (CH2–NPr), 48.7, 48.8 (CH2–N–CH3),
56.2, 56.3 (C2H5–CH2–N), 129.7 (CH arom), 131.8 (C arom),
(CH2)9–CH3), 1.50 (m, 2H, CH2–CH2N), 2.28 (q, 2H, J =
6.0 Hz, CH2(CH2–N)2), 2.86 (s, 3H, CH3–N), 3.05 (t, 2H, 3J =
3
7.8 Hz, C2H5–CH2–N), 3.64 (2t, 4H, J = 6.0 Hz, CH2–N),
7.4–7.6 (m, 5H, CH arom); 13C NMR (CDCl3, d ppm): 14.1
(CH3 dodecyl), 18.9 (N–CH2–CH2–CH2–N), 22.7, 26.2, 27.4,
28.7, 29.2, 29.3, 29.4, 29.5, 29.5, 31.9 (CH3–(CH2)10–CH2N),
42.0 (CH3–N), 45.2, 48.0 (CH2–N), 54.3 (C5H11–CH2–N),
127.1, 129.9 (CH arom a and b), 128.2 (C arom), 131.6 (CH
arom g), 162.2 (N–C–N). Calc. for C23H39F6N2P: C =
56.55%, H = 8.05%, N = 5.73%. Found: C = 56.22%,
H = 9.04%, N = 5.72%.
161.3 (N–C–N). Calc. for C22H36N4I2:
C = 43.29%,
H = 5.95%, N = 9.18%. Found: C = 41.63%, H = 5.95%,
N = 9.11%.
Synthesis of 49. The same procedure described for 20 was
used, starting from 48 (117 mg, 0.192 mmol) and sodium
tetrafluoroborate (142 mg, 0.233 mmol), which affords colourless
Synthesis of 46. The same procedure described for 36 was
used, starting from 43 (1.92 g, 4.53 mmol) and lithium triflate
(778 mg, 4.99 mmol), affording 36 as a colourless oil, that
1
prismatic crystals of 49 (yield 65%). Mp >340 1C. H NMR
(DMSO, d ppm): 0.60, 0.64 (2t, 6H, 3J = 7.2 Hz, CH3 propyl),
1.48 (m, 4H, CH2–CH3), 2.17 (m, 4H, CH2(CH2–N)2), 2.79,
2.83 (2s, 6H, CH3–N), 2.99 (m, 4H, C2H5–CH2–N), 3.58, 3.60
(2t, 8H, 3J = 6.0 Hz, CH2–N), 7.84, 7.86 (2s, 4H, CH arom);
1
decomposes at 350 1C, with a 95% yield. H NMR (CDCl3,
3
d ppm): 0.83 (t, 3H, J = 6.9 Hz, CH3 dodecyl), 0.9–1.3 (m,
18H, (CH2)9–CH3), 1.47 (m, 2H, CH2–CH2N), 2.26 (q, 2H,
3J = 6.0 Hz, CH2(CH2–N)2), 2.85 (s, 3H, CH3–N), 3.04 (t, 2H,
3J = 7.8 Hz, C2H5–CH2–N), 3.67 (2t, 4H, 3J = 6.0 Hz,
CH2–N), 7.50 (m, 5H, CH arom), 13C NMR (CDCl3, d ppm):
14.1 (CH3 dodecyl), 19.2 (N–CH2–CH2–CH2–N), 22.7, 26.2,
27.5, 28.7, 29.0, 29.2, 29.3, 29.4, 29.5, 29.6, 31.9
(CH3–(CH2)10–CH2N), 42.1 (CH3–N), 45.2, 48.1 (CH2–N),
54.3 (C10H21–CH2–N), 127.2, 129.9 (CH arom a and b), 128.2
(C arom), 131.6 (CH arom g), 162.3 (N–C–N). Probably,
owing to a too long relaxation time, no 13C signal was
observed for the anion. Calc. for C24H39F3N2O3S: C =
58.51%, H = 7.98%, N = 5.69%. Found: C = 58.50%,
H = 8.48%, N = 5.66%.
13C NMR (DMSO,
d ppm): 10.6 10.7 (CH3), 18.5
(N–CH2–CH2–CH2–N), 20.3, 20.4 (CH2–CH3), 41.6, 41.7
(CH3–N), 45.1, 45.2 (CH2–NPr), 47.9, 48.0 (CH2–N–CH3),
55.0 (C2H5–CH2–N), 128.9 (CH arom), 131.0 (C arom), 160.2
(N–C–N). Calc. for C22H36B2F8N4ꢂ1/2H2O: C = 49.01%,
H = 6.92%, N = 10.39%. Found C = 48.78%, H = 6.78%,
N = 10.43%.
Synthesis of 50. 48 (60 mg, 0.097 mmol), dissolved in a
minimum of distilled water was mixed with 2 ml of an
aqueous solution containing sodium tetraphenylborate (67 mg,
0.195 mmol) and stirred for 1 h. The resulting white solid was
filtered off, then recrystallised in a mixture of ethanol–water to
afford 50 as a white powder (yield 68%). Mp 315 1C. 1H NMR
(DMSO, d ppm): 0.60, 0.64 (2t, 6H, 3J = 7.5 Hz, CH3 propyl),
1.46 (m, 4H, CH2–CH3), 2.15 (q, 4H, 3J = 5.9 Hz,
CH2(CH2–N)2), 2.77, 2.81 (2s, 6H, CH3–N), 2.98 (m, 4H,
CH2–N), 3.56, 3.58 (2t, 8H, 3J = 5.9 Hz, CH2–N), 6.79 (t, 8H,
3J = 7.5 Hz, CH arom, g BPh4), 6.92 (t, 16H, 3J = 7.5 Hz, CH
arom, b BPh4), 7.17 (br, 16H, CH arom, a BPh4), 7.82, 7.83
(2s, 4H, CH arom), 13C NMR (DMSO, d ppm): 10.6 (CH3
propyl), 18.5 (N–CH2–CH2–CH2–N), 21.4 (CH2–CH3), 41.6,
41.7 (CH3–N), 45.2 48.0 (CH2–N), 55.0 (C2H5–CH2–N),
121.5, 125.2, 128.8 (CH arom BPh4), 135.5 (CH arom
amidine), 131.0 (C arom), 161.1 (N–C–N), 162.4, 163.0, 163.7,
164.3 (C arom, BPh4). Calc. for C70H76B2N4: C = 84.50%,
Synthesis of 47. The same procedure described for 22 was
used, starting from 43 (1.72 g, 4.06 mmol) and lithium bis-
(trifluoromethane)sulfonimide (1.28 mg, 4.47 mmol). 47 was
obtained as a colourless liquid, that decomposes at 200 1C,
with a 84% yield. 1H NMR (CDCl3, d ppm): 0.84 (t, 3H, 3J =
6.9 Hz, CH3 dodecyl), 0.9–1.3 (m, 18H, (CH2)9–CH3), 1.48 (m,
3
2H, CH2–CH2N), 2.26 (q, 2H, J = 6.0 Hz, CH2(CH2–N)2),
2.84 (s, 3H, CH3–N), 3.04 (t, 2H, 3J
= 7.9 Hz,
C10H21–CH2–N), 3.63 (2t, 4H, 3J = 6.0 Hz, CH2–N),
7.4–7.6 (m, 5H, CH arom), 13C NMR (CDCl3, d ppm): 14.1
(CH3 dodecyl), 19.0 (N–CH2–CH2–CH2–N), 22.6, 26.1, 27.4,
28.7, 28.9, 29.2, 29.3, 29.4, 29.5, 31.9 (CH3–(CH2)10–CH2N),
42.0 (CH3–N), 45.3, 48.1 (CH2–N), 54.4 (C10H21–CH2–N),
ꢁc
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H = 7.70%, N = 5.63%. Found C = 84.78%, H = 7.58%,
N = 5.42%.
Synthesis of 54. The same procedure described for 51 was
used, starting from 53 (117 mg, 0.166 mmol) and sodium
tetrafluoroborate (100 mg, 0.911 mmol). After recrystallisation in
water, 54 was obtained as a white powder with a yield of 60%.
Mp 306–308 1C. 1H NMR (DMSO, d ppm): 0.76, 0.79 (2t, 6H,
3J = 7.2 Hz, CH3 hexyl), 0.9–1.2 (m, 12H, (CH2)3–CH3), 1.47
(br, 4H, CH2–CH2–N), 2.16 (br, 4H, CH2(CH2–N)2), 2.78,
2.81 (2s, 6H, CH3–N), 3.02 (m, 4H, C5H11–CH2–N), 3.57, 3.59
(2t, 8H, 3J = 6.3 Hz, CH2–N), 7.87 (s, 4H, CH arom);
Synthesis of 51. 48 (100 mg, 0.162 mmol) dissolved in a
minimum of distilled water was mixed with 1 ml an aqueous
solution containing of ammonium hexafluorophosphate
(53 mg, 0.325 mmol) and stirred for 1 h. The resulting white
solid was filtered off, then recrystallised in distilled water to
afford colourless crystals of 51, suitable for X-ray diffraction
analysis (yield 57%). Mp >320 1C. 1H NMR (DMSO,
d ppm): 0.61, 0.64 (2t, 6H, 3J = 7.2 Hz, CH3 propyl),
1.48 (m, 4H, CH2–CH3), 2.17 (m, 4H, CH2(CH2–N)2), 2.79,
2.83 (2s, 6H, CH3–N), 3.00 (m, 4H, C2H5–CH2–N), 3.59,
3.61 (2t, 8H, 3J = 6.0 Hz, CH2–N), 7.85, 7.86 (2s, 4H,
CH arom), 13C NMR (DMSO, d ppm): 10.7 (CH3), 18.5
(N–CH2–CH2–CH2–N), 20.4 (CH2–CH3), 41.7, 41.8
(CH3–N), 45.1, 45.2 (CH2–NPr), 47.9, 48.0 (CH2–N–CH3),
55.1 (C2H5–CH2–N), 129.2 (CH arom), 131.0 (C arom), 160.5
(N–C–N). Calc. for C22H36P2F12N4: C = 40.87%, H = 5.61%,
N = 8.67%. Found: C = 39.81%, H = 5.69%, N = 8.18%.
13C NMR (DMSO,
d ppm): 13.7 (CH3 hexyl), 18.5
(N–CH2–CH2–CH2–N), 21.8, 21.9 (CH2–CH3), 25.1, 25.5,
26.7, 26.9, 30.3, 30.6 (C2H5–(CH2)3–CH2–N), 41.4, 41.7
(CH3–N), 45.2, 47.9 (CH2–N-hexyl and CH2–N–CH3), 53.4,
53.5 (C5H11–CH2–N), 128.8 (CH arom), 131.1 (C arom), 160.1
(N–C–N). Calc. for C28H48B2F8N4ꢂ1/2H2O: C = 53.95%,
H = 7.92%, N = 8.99%. Found: C = 54.00%, H = 7.88%,
N = 8.98%.
Synthesis of 55. The same procedure described for 50 was
used, starting from 53 (50 mg, 0.083 mmol) and sodium
tetraphenylborate (60 mg, 0.175 mmol). 55 was obtained as
1
Synthesis of 52. The same procedure described for 51 was
used, starting from 48 (247 mg, 0.405 mmol) and lithium
bis(trifluoromethane)sulfonimide (290 mg, 1.01 mmol). After
recrystallisation in a water–acetone mixture, 52 was obtained
as a white solid with a yield of 61%. Mp 134–135 1C. 1H NMR
a white solid with a yield of 77%. Mp >300 1C. H NMR
(DMSO, d ppm): 0.76, 0.80 (2t, 6H, 3J = 7.5 Hz, CH3 hexyl),
0.9–1.2 (m, 12H, N–CH2–(CH2)3–C2H5), 1.46 (br, 4H,
CH2–CH3), 2.14 (br, 4H, CH2(CH2–N)2), 2.76, 2.79 (2s, 6H,
CH3–N), 3.00 (m, 4H, CH2–N), 3.55, 3.57 (2t, 8H, 3J = 6.0 Hz,
CH2–N), 6.79 (t, 8H, 3J = 7.5 Hz, CH aromg BPh4), 6.92
3
((CD3)2CO, d ppm): 0.73 (t, 6H, J = 6.9 Hz, CH3 propyl),
1.65 (m, 4H, CH2–CH3), 2.36 (q, 4H, 3J = 6.0 Hz,
CH2(CH2–N)2), 3.03, 3.04 (2s, 6H, CH3–N), 3.26 (m, 4H,
C2H5–CH2–N), 3.78, 3.81 (2t, 8H, 3J = 6.0 Hz, CH2–N), 8.05
(s, 4H, CH arom); 13C NMR ((CD3)2CO, d ppm): 10.6, 10.7
(CH3 propyl), 19.4 (N–CH2–CH2–CH2–N), 21.3, 21.4
(CH2–CH3), 42.2, 42.3 (CH3–N), 46.2, 46.3 (CH2–N-propyl),
49.0, 49.0 (CH2–N–CH3), 56.3, 56.4 (C2H5–CH2–N), 121.0
(q, CF3, 1J = 317 Hz), 130.0 (CH arom), 132.4 (C arom),
161.7 (N–C–N). Probably, owing to a too long relaxation
time, no 13C signal was observed for the anion. Calc. for
C25H36F12N6O8S4: C = 34.06%, H = 3.96%, N = 9.17%.
Found C = 33.76%, H = 3.98%, N = 9.16%.
3
(t, 16H, J = 7.5 Hz, CH arom, b BPh4), 7.17 (br, 16H, CH
arom, a BPh4), 7.83 (s, 4H, CH, arom); 13C NMR (DMSO,
d ppm): 13.7 (CH3 hexyl), 18.5 (N–CH2–CH2–CH2–N), 21.8,
21.9 (CH2–CH3), 25.1, 25.5, 26.7, 26.9, 30.3, 30.6
(C2H5–(CH2)3–CH2–N), 41.7 (CH3–N), 45.2 (CH2–N-hexyl),
47.9 (CH2–N–CH3), 53.4, 53.5 (C5H11–CH2–N), 121.5, 125.3,
128.8 (CH arom, BPh4), 131.0 (C arom), 135.5 (CH arom,
amidine), 160.0 (N–C–N), 162.4, 163.0, 163.6, 164.3 (C arom
BPh4). Calc. for C76H88B2N4: C = 84.59%, H = 8.22%,
N = 5.19%. Found: C = 84.80%, H = 8.12%, N = 5.01%.
Synthesis of 56. The same procedure described for 51 was
used, starting from 53 (50 mg, 0.083 mmol) and ammonium
hexafluorophosphate (27 mg, 0.166 mmol). After recrystallisa-
tion in water, colourless crystals of 56 were obtained with a
Synthesis of 53. 3 (1.50 g, 5.56 mmol) and 1-bromohexane
(1.93 g, 11.7 mmol) were dissolved in 40 ml of dry DMF and
the mixture was heated at 70 1C for 5 days under argon. After
cooling, the white solid was filtered off, washed with 2 ꢃ 15 ml
of diethyl ether, then dried under vacuum, affording 53 as a
very hygroscopic white solid with a yield of 68%. Mp >
280 1C. 1H NMR (D2O + tBuOH, d ppm): 0.75, 0.79 (2t, 6H,
3J = 7.2 Hz, CH3 hexyl), 0.9–1.2 (m, 12H, (CH2)3–CH3), 1.55
1
yield of 59%. Mp 313–315 1C. H NMR ((CD3)2O, d ppm):
0.78, 0.82 (2t, 6H, J = 7.2 Hz, CH3 hexyl), 1.0–1.3 (m, 12H,
3
(CH2)3–CH3), 1.66 (m, 4H, CH2–CH2–N), 2.36 (q, 4H,
3J = 6.0 Hz, CH2(CH2–N)2), 3.01, 3.02 (2s, 6H, CH3–N),
3.28 (m, 4H, C5H11–CH2–N), 3.76, 3.81 (2t, 8H, 3J = 5.7 Hz,
CH2–N), 8.04, 8.05 (2s, 4H, CH arom); 13C NMR ((CD3)2O,
d ppm): 14.2, 14.3 (CH3 hexyl), 19.7 (N–CH2–CH2–CH2–N),
23.1, 23.2 (CH2–CH3), 26.6, 26.9, 28.2, 28.4, 31.8, 32.0
(C2H5–(CH2)3–CH2–N), 42.6, 42.7 (CH3–N), 46.6 (CH2–
N-hexyl), 49.3 (CH2–N–CH3), 55.2, 55.3 (C5H11–CH2–N),
130.3 (CH arom), 132.7 (C arom), 161.9 (N–C–N). Calc. for
(m, 4H, CH2–CH2–N), 2.24 (q, 4H, 3J
= 5.8 Hz,
CH2(CH2–N)2), 2.88–2.89 (2s, 6H, CH3–N), 3.12, 3.15
(2t, 4H, 3J = 7.5 Hz, C5H11–CH2–N), 3.62, 3.65 (2t, 8H,
3J = 5.8 Hz, CH2–N), 7.82 (s, 4H, CH arom); 13C NMR
(D2O
+
tBuOH,
d
ppm): 13.9 (CH3 hexyl), 19.3
(N–CH2–CH2–CH2–N), 22.3, 22.4 (CH2–CH3), 25.6, 26.0,
27.3, 27.5, 30.8, 30.9, 31.0 (C2H5–(CH2)3–CH2–N), 42.2
(CH3–N), 46.0 (CH2–N-hexyl), 48.8 (CH2–N–CH3), 54.6,
54.7 (C5H11–CH2–N), 129.7 (CH arom), 131.6 (C arom),
C28H48F12N4P2ꢂ1.5H2O:
C = 44.39%, H = 6.78%,
N = 7.39%. Found: C = 44.10%, H = 6.58%, N = 7.55%.
Synthesis of 57. The same procedure described for 52 was
used, starting from 53 (196 mg, 0.326 mmol) and lithium
bis(trifluoromethane)sulfonimide (234 mg, 0.816 mmol). After
recrystallisation in a water–acetone mixture, 57 was obtained
161.2 (N–C–N). Calc. for C28H48Br2N4ꢂ1.4H2O:
C =
53.74%, H = 8.18%, N = 8.95%. Found: C = 53.61%,
H = 8.12%, N = 9.10%.
ꢁc
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1196 | New J. Chem., 2010, 34, 1184–1199

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as a white solid with a yield of 68%. Mp 70 1C. 1H NMR
((CD3)2CO, d ppm): 0.78, 0.82 (2t, 6H, 3J = 6.9 Hz, CH3
hexyl), 1.0–1.3 (m, 12H, (CH2)3–CH3), 1.66 (m, 4H,
CH2–CH2–N), 2.36 (q, 4H, 3J = 6.0 Hz, CH2(CH2–N)2),
3.03 (s, 6H, CH3–N), 3.29 (m, 4H, C2H5–CH2–N), 3.77, 3.82
a white powder with a yield of 83%. Mp >300 1C
(decomposition at 240 1C). H NMR (DMSO, d ppm): 0.85
1
(t, 6H, 3J = 6.6 Hz, CH3 dodecyl), 0.9–1.3 (m, 36H,
CH3–(CH2)9–C2H4–N), 1.43 (br, 4H, C10H21–CH2–CH2N),
2.11 (br, 4H, CH2(CH2–N)2), 2.72, 2.76 (2s, 6H, CH3–N),
2.96 (m, 4H, C11H23–CH2–N), 3.52, 3.53 (2t, 8H, 3J = 6.0 Hz,
CH2–N), 6.80 (t, 8H, 3J = 7.5 Hz, CH aromg BPh4), 6.93
3
(2t, 8H, J = 6.0 Hz, CH2–N), 8.06, 8.07 (2s, 4H, CH arom);
13C NMR ((CD3)2CO, d ppm): 14.1, 14.2 (CH3 hexyl), 19.9
(N–CH2–CH2–CH2–N), 23.1, 23.1 (CH2–CH3), 26.6, 26.9,
28.2, 28.4, 31.8, 32.0 (C2H5–(CH2)3–CH2–N), 42.6, 42.7
(CH3–N), 46.7 (CH2–N-hexyl), 49.4 (CH2–N–CH3), 55.2,
55.3 (C5H11–CH2–N), 121.1 (q, CF3), 130.4 (CH arom),
132.7 (C arom), 161.9 (N–C–N). Probably, owing to a too
long relaxation time, no 13C signal was observed for the anion.
Calc. for C32H48F12N6O8S4: C = 38.40%, H = 4.83%,
N = 8.40%. Found C = 38.02%, H = 4.99%, N = 8.37%.
3
(t, 16H, J = 7.5 Hz, CH arom, b BPh4), 7.18 (br, 16H, CH
arom, a BPh4), 7.76, 7.77 (2s, 4H, CH arom); 13C NMR
(DMSO,
d
ppm):
13.9
(CH3
dodecyl),
18.5
(N–CH2–CH2–CH2–N), 22.1 (CH2–CH3), 25.5, 25.9, 26.8,
27.1, 28.2, 28.6, 28.7, 28.8, 29.0, 29.1, 31.3
(C2H5–(CH2)9–CH2–N), 41.4, 41.7 (CH3–N), 45.2 (CH2–N-
dodecyl), 47.9 (CH2–N–CH3), 53.5 (C11H23–CH2–N), 121.5,
125.3, 128.8 (CH arom, BPh4), 130.1 (C arom), 135.5 (CH
arom, amidine), 160.0 (N–C–N), 162.4, 163.0, 163.7, 164.3 (C
Synthesis of 58. The same procedure described for 53 was
used, starting from 23 (1.50 g, 5.56 mmol) and 1-bromododecane
(2.77 g, 11.1 mmol) (reaction time = two days). The
compound was recrystallised from a 1 : 1 water–acetone mixture,
affording colourless crystalline needles of 58, suitable for
X-ray diffraction, with a yield of 48%. Mp >300 1C (decom-
arom BPh4). Calc. for C88H112B2N4:
C = 84.73%,
H = 9.05%, N = 4.49%. Found: C = 84.30%, H =
9.20%, N = 4.08%.
Synthesis of 61. 58 (200 mg, 0.260 mmol), dissolved in a
minimum of distilled water was mixed with 0.5 ml of an
aqueous solution containing ammonium hexafluorophosphate
(85 mg, 0.520 mmol) and stirred for 1 h. The resulting white
solid was filtered off, washed with 3 ꢃ 1 ml of water, then dried
under vacuum affording 61 as a white solid with a yield
of 57%. Mp >280 1C (decomposition).1H NMR (DMSO,
d ppm): 0.84, 0.85 (2t, 6H, 3J = 6.6 Hz, CH3 dodecyl), 0.9 1.3
(2m, 36H, CH3–(CH2)9–C2H4–N), 1.46 (br, 4H,
C10H21–CH2–CH2N), 2.16 (br, 4H, CH2(CH2–N)2), 2.77,
2.81 (2s, 6H, CH3–N), 3.00 (m, 4H, C11H23–CH2–N), 3.57,
1
position at 200 1C). H NMR (MeOD, d ppm): 0.89 (t, 6H,
3J
=
6.8 Hz, CH3 dodecyl), 1.09–1.26 (m, 36H,
CH3–(CH2)9–C2H4–N), 1.59 (q, 4H, 3J
C10H21–CH2–CH2N), 2.30 (q, 4H, 3J
=
=
7.5 Hz,
6.0 Hz,
CH2(CH2–N)2), 2.90 2.92 (2s, 6H, CH3–N), 3.13 3.15 (2t,
4H, 3J = 7.5 Hz, C11H23–CH2–N), 3.69 3.71 (2t, 8H,
3J = 6.0 Hz, CH2–N) 7.95 (s, 4H, CH arom); 13C NMR
(D2O
+ tBuOH, d ppm): 13.0 (CH3 dodecyl), 18.6
(N–CH2–CH2–CH2–N), 22.3 (CH2–CH3), 26.0, 26.4, 27.3,
27.4, 28.7, 29.0, 29.0, 29.1, 29.1 29.2, 29.3, 29.4, 31.7
(C2H5–(CH2)9–CH2–N), 41.2, 41.3 (CH3–N), 45.4 (CH2–N-
dodecyl), 48.2 (CH2–N–CH3), 54.2 (C11H23–CH2–N), 129.2
(CH arom), 131.6 (C arom), 160.7 (N–C–N). Calc. for
C40H72Br2N4ꢂ3H2O: C = 58.38%, H = 9.55%, N =
6.81%. Found: C = 58.12%, H = 10.10%, N = 6.82%.
3.59 (2t, 8H, 3J = 6.3 Hz, CH2–N), 7.86 (s, 4H, CH arom); 13
C
NMR (DMSO, d ppm): 13.9 (CH3 dodecyl), 18.5
(N–CH2–CH2–CH2–N), 22.1 (CH2–CH3), 25.5, 25.9, 26.8,
27.1, 28.3, 28.6, 28.7, 28.8, 29.0, 29.1, 31.3
(C2H5–(CH2)9–CH2–N), 41.4, 41.7 (CH3–N), 45.2 (CH2–N–
dodecyl), 47.9 (CH2–N–CH3), 53.5 (C11H23–CH2–N), 128.8
(CH arom), 131.0 (C arom), 160.0 (N–C–N). Calc. for
C40H72F12N4P2ꢂH2O: C = 52.39%, H = 8.13%, N =
6.11%. Found: C = 51.99%, H = 7.70%, N = 6.12%.
Synthesis of 59. The same procedure described for 49 was
used, starting from 58 (400 mg (0.520 mmol) and sodium
tetrafluoroborate (114 mg, 1.04 mmol). 59 was obtained as a
white powder with a yield of 48%. Mp >300 1C (decomposition
at 240 1C). 1H NMR (DMSO, d ppm): 0.84, 0.85 (2t, 6H,
3J
= 6.6 Hz, CH3 dodecyl), 0.99, 1.21 (2m, 36H,
Synthesis of 62. The same procedure described for 52 was
used, starting from 58 (397 mg, 0.482 mmol) and lithium
bis(trifluoromethane)sulfonimide (346 mg, 1.20 mmol). 62
was obtained as a white solid with a yield of 86%.
Mp 106–108 1C. 1H NMR (CDCl3, d ppm): 0.86 (t, 6H,
3J = 6.6 Hz, CH3 dodecyl), 0.95–1.35 (m, 36H, CH3–(CH2)9–
C2H4–N), 1.50 (br, 4H, C10H21–CH2–CH2N), 2.31 (br, 4H,
CH2(CH2–N)2), 2.85, 2.87 (2s, 6H, CH3–N), 3.04, 3.07 (2t, 4H,
3J = 7.2 Hz, C11H23–CH2–N), 3.65 (br, 8H, CH2–N),
7.87, 7.88 (2s, 4H, CH arom); 13C NMR (CDCl3, d ppm):
14.1 (CH3 dodecyl), 18.7 (N–CH2–CH2–CH2–N), 22.6
(CH2–CH3), 26.6, 27.5, 28.7, 28.9, 29.3, 29.3, 29.4, 29.4,
29.5, 29.5, 29.6, 31.9 (C2H5–(CH2)9–CH2–N), 41.9, 42.1
(CH3–N), 45.4 (CH2–N-dodecyl), 48.2 (CH2–N–CH3), 54.7
(C11H23–CH2–N), 119.9 (q, CF3), 129.3 (CH arom), 131.2
(C arom), 160.8 (N–C–N). Probably, owing to a too long
relaxation time, no 13C signal was observed for the anion.
CH3–(CH2)9–C2H4–N), 1.45 (br, 4H, C10H21–CH2–CH2N),
2.16 (br, 4H, CH2(CH2–N)2), 2.77, 2.81 (2s, 6H, CH3–N),
3.00 (m, 4H, C11H23–CH2–N), 3.57, 3.59 (2t, 8H, 3J = 6.3 Hz,
CH2–N), 7.85 (s, 4H, CH arom); 13C NMR (DMSO, d ppm):
13.9 (CH3 dodecyl), 18.5 (N–CH2–CH2–CH2–N), 22.1
(CH2–CH3), 25.5, 25.9, 26.8, 27.1, 28.3, 28.6, 28.7, 28.8,
29.0, 29.1, 31.3 (C2H5–(CH2)9–CH2–N), 41.4, 41.7 (CH3–N),
45.2
(CH2–N-dodecyl),
47.9
(CH2–N–CH3),
53.5
(C11H23–CH2–N), 128.8 (CH arom), 131.0 (C arom), 160.0
(N–C–N). Calc. for C40H72B2F8N4ꢂ1/2H2O: C = 61.39%,
H = 7.16%, N = 9.27%. Found: C = 61.35%, H =
7.01%, N = 9.57%.
Synthesis of 60. The same procedure described for 50 was
used, starting from 58 (80 mg, 0.104 mmol) and sodium
tetraphenylborate (75 mg, 0.219 mmol). 60 was obtained as
ꢁc
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Calc. for C44H72F12N6O8S4: C = 45.19%, H = 6.21%,
N = 7.19%. Found: C = 44.87%, H = 6.30%, N = 7.06%.
BPh4). Calc. for C96H128B2N4ꢂH2O: C = 83.69%, H = 9.51%,
N = 4.07%. Found: C = 83.70%, H = 9.16%, N = 3.71%.
Synthesis of 66. 63 (100 mg (0.113 mmol), dissolved in 2 ml
of methanol, was mixed with 3 ml of a methanolic solution
containing ammonium hexafluorophosphate (50 mg, 0.307 mmol)
and stirred for 1 h. The resulting white solid was filtered off,
washed with 2 ꢃ 3 ml of methanol, then dried under vacuum
affording 66 as a white solid with a yield of 98%. Mp B280 1C
Synthesis of 63. The same procedure described for 48 was
used, starting from 23 (1.50 g, 5.56 mmol) and 1-bromo-
hexadecane (2.77 g, 11.1 mmol) (reaction time = two days).
The compound was recrystallised from a 1 : 1 water–acetone
mixture, affording colourless crystalline needles of 63 with
1
66% yield. Mp >300 1C (decomposition). H NMR (MeOD,
1
3
(decomposition at 230 1C). H NMR (DMSO, d ppm): 0.85
d ppm): 0.89 (t, 6H, J = 6.8 Hz, CH3 hexadecyl), 1.08–1.27
(m, 52H, CH3–(CH2)13–C2H4–N), 1.59 (q, 4H, J = 7.5 Hz,
(t, 6H, 3J = 6.6 Hz, CH3 hexadecyl), 0.8–1.3 (m, 52H,
3
CH3–(CH2)13–C2H4–N), 1.45 (q, 4H, 3J
C14H29–CH2–CH2N), 2.16 (q, 4H, 3J
=
7.5 Hz,
C14H29–CH2–CH2N), 2.30 (q, 4H, 3J
=
6.0 Hz,
=
6.0 Hz,
CH2(CH2–N)2), 2.90, 2.92 (2s, 6H, CH3–N), 3.16, 3.18 (2t,
4H, 3J = 7.5 Hz, C15H31–CH2–N), 3.69, 3.71 (2t, 8H, 3J = 6.0
Hz, CH2–N), 7.95 (s, 4H, CH arom); 13C NMR (MeOD,
d ppm): 13.0 (CH3 hexadecyl), 18.6 (N–CH2–CH2–CH2–N),
22.3 (CH2–CH3), 26.0, 26.4, 27.4, 29.0, 29.0, 29.4, 29.4, 31.7
(C2H5–(CH2)13–CH2–N), 41.2 (CH3–N), 45.4 (CH2–N-
hexadecyl), 48.2 (CH2–N–CH3), 54.2 (C15H31–CH2–N),
129.2 (CH arom), 131.6 (C arom), 160.7 (N–C–N). Calc. for
C48H88Br2N4ꢂ1/2H2O: C = 64.77%, H = 10.08%, N =
6.29%. Found: C = 64.98%, H = 10.59%, N = 6.29%.
3
CH2(CH2–N)2), 2.77, 2.80 (2s, 6H, CH3–N), 3.0 (t, 4H, J =
7.8 Hz, C15H31–CH2–N), 3.57, 3.59 (2t, 8H, 3J = 6.3 Hz,
CH2–N), 7.86 (s, 4H, CH arom). The compound was not
characterized by 13C NMR because of its insolubility in usual
solvents. Calc. for C48H88F12N4P2ꢂ2H2O: C = 55.05%,
H = 8.86%, N = 5.35%. Found: C = 54.85%, H = 8.60%,
N = 5.60%.
Synthesis of 67. 63 (274 mg, 0.311 mmol), dissolved in 20 ml
of distilled water, was mixed with 3 ml of an aqueous solution
containing lithium bis(trifluoromethane)sulfonimide (223 mg,
0.777 mmol). After 1 h stirring, the resulting white solid was
filtered off, washed with 2 ꢃ 5 ml of water, then dried under
vacuum affording 66 as a white solid with a yield of 71%. Mp
103–106 1C. 1H NMR (CDCl3, d ppm): 0.86 (t, 6H, 3J = 6.6 Hz,
CH3 hexadecyl), 0.95–1.32 (m, 52H, CH3–(CH2)13–C2H4–N),
1.50 (br, 4H, C14H29–CH2–CH2N), 2.30 (br, 4H,
CH2(CH2–N)2), 2.83, 2.86 (2s, 6H, CH3–N), 3.03, 3.05 (2t,
4H, 3J = 7.5 Hz, C15H31–CH2–N), 3.63 (br, 8H, CH2–N),
7.86, 7.87 (2s, 4H, CH arom); 13C NMR (CDCl3, d ppm): 14.0
(CH3 hexadecyl), 18.7 (N–CH2–CH2–CH2–N), 22.7
(CH2–CH3), 26.6, 27.5, 28.7, 28.9, 29.3, 29.4, 29.4, 29.5,
29.6, 29.7, 29.7, 31.9 (C2H5–(CH2)13–CH2–N), 41.8, 42.0
(CH3–N), 45.4 (CH2–N-hexadecyl), 48.1 (CH2–N–CH3), 54.7
(C15H31–CH2–N), 119.9 (q, CF3), 129.2 (CH arom), 131.3
(C arom), 160.7 (N–C–N). Calc. for C52H88F12N6O8S4:
C = 48.74%, H = 6.92%, N = 6.56%. Found: C = 48.56%,
H = 7.01%, N = 6.38%.
Synthesis of 64. 63 (267 mg, 0.303 mmol) dissolved in 100 ml
of distilled water at 55 1C was mixed with 3 ml of an aqueous
solution containing sodium tetrafluoroborate (115 mg,
1.045 mmol) and stirred for 1 h. The resulting white solid
was filtered off, washed with 2 ꢃ 5 ml of water, then dried
under vacuum affording 64 as a white solid with a yield of
68%. Mp >300 1C (decomposition at 240 1C). 1H NMR
3
(DMSO, d ppm): 0.85 (t, 6H, J = 6.6 Hz, CH3 hexadecyl),
0.9–1.3 (m, 52H, CH3–(CH2)13–C2H4–N), 1.46 (br, 4H,
C14H29–CH2–CH2N), 2.16 (q, 4H, 3J
=
5.7 Hz,
3
CH2(CH2–N)2), 2.77, 2.81 (2s, 6H, CH3–N), 3.0 (t, 4H, J =
7.5 Hz, C15H31–CH2–N), 3.57, 3.59 (2t, 8H, 3J = 6.3 Hz,
CH2–N), 7.86 (s, 4H, CH arom). The compound was not
characterized by NMR 13C because of its insolubility in usual
solvents. Calc. for C48H88B2F8N4ꢂH2O: C = 63.15%, H =
9.94%, N = 6.26%. Found: C = 63.21%, H = 9.77%,
N = 6.03%.
Synthesis of 65. The same procedure described for 50 was
used, starting from 63 (157 mg, 0.178 mmol) and sodium
tetraphenylborate (203 mg, 0.593 mmol). 65 was obtained as a
white powder with a yield of 43%. Mp 235 1C. 1H NMR
Acknowledgements
We thank the Universite de Strasbourg, the International
´
Centre for Frontier Research in Chemistry (FRC), Strasbourg,
the Institut Universitaire de France, the Ministry of Education
and Research and the CNRS for financial support.
3
(DMSO, d ppm): 0.85 (t, 6H, J = 6.6 Hz, CH3 hexadecyl),
0.85–1.26 (m, 52H, CH3–(CH2)13–C2H4–N), 1.44 (br, 4H,
C14H29–CH2–CH2N), 2.12 (br, 4H, CH2(CH2–N)2), 2.74,
2.77 (2s, 6H, CH3–N), 2.97, 2.99 (2t, 4H, 3J = 7.5 Hz,
C15H31–CH2–N), 3.54 (br, 8H, CH2–N), 6.79 (t, 8H, 3J =
Notes and references
3
7.5 Hz, CH arom, g, BPh4), 6.92 (t, 16H, J = 7.5 Hz, CH
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1198 | New J. Chem., 2010, 34, 1184–1199

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