Synthesis and properties of a new family of phosphorus- and nitrogen-containing ionenes

Article abstract of DOI:10.1134/S0012500815120034

Polyquaternization reactions of bis[2-(4-pyridyl)ethyl]phenylethylphosphine oxide and tris[2-(4-pyridyl)ethyl]phosphine oxide with 1,4-dibromobutane were implemented for the first time to give linear (water-soluble) and cross-linked (limitedly water swelling), respectively, representatives of new phosphorus- and nitrogen-containing ionenes. The synthesized linear ionenes react with heparin and polyacrylic acid yielding water-insoluble polyelectrolyte complexes.

Full text of DOI:10.1134/S0012500815120034

ISSN 0012ꢀ5008, Doklady Chemistry, 2015, Vol. 465, Part 2, pp. 286–290. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © V.L. Mikhailenko, V.N. Kizhnyaev, S.I. Verkhoturova, K.A. Apartsin, N.K. Gusarova, E.G. Grigor’ev, B.A. Trofimov, 2015, published in Doklady Akademii
Nauk, 2015, Vol. 465, No. 4, pp. 446–450.
CHEMISTRY
Synthesis and Properties
of a New Family of Phosphorusꢀ and NitrogenꢀContaining
Ionenes
b
b
a
V. L. Mikhailenko , V. N. Kizhnyaev , S. I. Verkhoturova ,
K. A. Apartsin , N. K. Gusarova , Corresponding Member of the RAS E. G. Grigor’evc,
c
a
a
and Academician of the RAS B. A. Trofimov
Received June 18, 2015
Abstract—Polyquaternization reactions of bis[2ꢀ(4ꢀpyridyl)ethyl]phenylethylphosphine oxide and tris[2ꢀ
(
4ꢀpyridyl)ethyl]phosphine oxide with 1,4ꢀdibromobutane were implemented for the first time to give linear
(waterꢀsoluble) and crossꢀlinked (limitedly water swelling), respectively, representatives of new phosphorusꢀ
and nitrogenꢀcontaining ionenes. The synthesized linear ionenes react with heparin and polyacrylic acid
yielding waterꢀinsoluble polyelectrolyte complexes.
DOI: 10.1134/S0012500815120034
Ionenes, i.e., heterochain polymers containing
It is noteworthy that pyridinium polycations conꢀ
positively charged quaternary nitrogen atoms in the taining phosphoryl groups have not been reported in
backbone, attract persistent interest of researchers as the literature, although it is known, for example, that
an important class of polycations [1–5]. They are used tris(2ꢀorganylpyridiniumethyl)phosphine oxide trihaꢀ
in the production of pharmaceutical drugs (in particuꢀ lides exhibit pronounced antibacterial properties [8].
lar, to purify alendronic acid used for bone tissue therꢀ In addition, neutral polypyridylphosphine oxides are
apy, including sarcoma treatment [4]), as crossꢀlinking precursors for the design of antibacterial drugs [8] and
agents [1], elastomers [3], and radical reaction initiaꢀ serve as building blocks for organic and organometallic
tors [1]. Compounds possessing clearꢀcut thixotropic synthesis [8–10].
[
2], biocidal [5], and antimicrobial [6] properties were
This communication describes the first study of
reactions of bis[2ꢀ(4ꢀpyridyl)ethyl]phenylethylphosꢀ
found among ionenes.
phine oxide (
oxide (II) with 1,4ꢀdibromobutane giving linear
waterꢀsoluble) and crossꢀlinked (limitedly water
swelling), respectively, phosphorusꢀ and nitrogenꢀ
containing polycations with the goal to synthesize a
new class of phosphorusꢀ and nitrogenꢀcontaining
ionenes.
I) and tris[2ꢀ(4ꢀpyridyl)ethyl]phosphine
The traditional method of ionene synthesis is based
on atomꢀeconomical reaction of tertiary aliphatic and
aromatic amines with dihaloalkanes [1, 3, 5]. The
same method was used to synthesize ionenes based on
bispyridines [3] and bisazoles [7]. The latter are able to
form interpolymer polyelectrolyte complexes with
synthetic (polyacrylic acid) and natural (heparin)
polyanions, which, in particular, indicates a potenꢀ
tial antiheparin activity of azoleꢀcontaining ioneꢀ
nes [7].
(
Bispyridylphosphine oxide (
for the first time in 52% yield by the reaction of bis[2ꢀ
4ꢀpyridyl)ethyl]phosphine oxide with styrene in the
I) was synthesized here
(
KOH–DMSO system. The initial bis[2ꢀ(4ꢀ
pyridyl)ethyl]phosphine oxide was prepared by an
original method [11, 12] comprising the generation of
phosphine from red phosphorus and aqueous potasꢀ
sium hydroxide, the addition of phosphine to 4ꢀ
vinylpyridine, and oxidation of the resulting bis[2ꢀ(4ꢀ
pyridyl)ethyl]phosphine in air to the corresponding
secondary phosphine oxide (Scheme 1).
a
Favorsky Institute of Chemistry, Siberian Branch,
Russian Academy of Sciences, Irkutsk, Russia
b
Irkutsk State University, ul. Karla Marksa 1,
Irkutsk, 664003 Russia
c
Irkutsk Scientific Center of Surgery and Traumatology,
ul. Bortsov Revolutsii 1, Irkutsk, 664003 Russia
eꢀmail: boris_trofimov@irioch.irk.ru
286

SYNTHESIS AND PROPERTIES OF A NEW FAMILY
N
287
N
N
1
. KOH/H O/toluene
H
2
Pn
P
KOH/DMSO
P
O
N/KOH/DMSO
2
.
N
O
3
. O2 (air
)
I
Scheme 1. Synthesis of bis[2ꢀ(4ꢀpyridyl)ethyl]phenylethylphosphine oxide.
Experiments showed that bispyridylphosphine
The elemental analysis data of ionenes IIIa and
oxide ( ) readily (60 C, 24 h, ethanol, 1 : 1 molar ratio IIIb are also consistent with the presented structure
I
°
of the reactants) reacts with 1,4ꢀdibromobutane to (Table 1).
give linear ionene type polymers (III) in 38–51%
In aqueous solutions, linear ionenes (IIIa, IIIb
)
behave as typical polyelectrolytes for which the polyꢀ
electrolyte swelling in water occurs with dilution (Fig. 1,
yields. Two samples of these ionenes were prepared
IIIa, IIIb), their yields (Table 1) and the viscosity of
(
their aqueous solutions (Fig. 1) depending on the
reactant concentrations in ethanol.
The obtained ionenes IIIa and IIIb are light pinkꢀ
colored powders decomposing above 280°C. The IR
curves a and b). Ionene IIIa obtained at lower concenꢀ
tration of coꢀmonomers in ethanol (Table 1, run 1) is
characterized by somewhat higher viscosity of aqueous
solutions (Fig. 1, curve a) than IIIb (Fig. 1, curve b).
spectra of ionenes IIIa and IIIb contain characteristic
Apparently, polyquaternization is heterogeneous in
more concentrated reaction mixtures and homogeꢀ
neous in dilute ones, which promotes the formation of
highꢀmolecularꢀmass polycations.
absorption bands of the phosphine oxide P=O group
–1
centered at 1166 cm and for the pyridinium ring at
–1
1
516, 1599, and 1637 cm .
1
The data of H NMR spectra confirm the structure
Since the physiological activity of ionenes is largely
determined by their ability to form interpolymer comꢀ
plexes with negatively charged polyelectrolytes [7], we
studied the reactions of ionene IIIa with polyacrylic
acid and heparin. These reactions can be schematiꢀ
of ionenes IIIa and IIIb
8
(
δ
, ppm, D O): 8.71 d and
2
.65 d (pyridine ring protons, 3JHH = 6 Hz), 8.03–7.96 m
(
(
phenyl ring protons), 4.54, 3.27, 2.51, and 2.07 m
methylene protons).
31
The P NMR
(
δ
, D O) spectra of ionenes IIIa cally depicted as the interaction of positively charged
Р
2
and IIIb exhibit a broadened signal at 55–56 ppm pyridine moieties and negatively charged carboxy
characteristic of tertiary tris(organylpyridiniumꢀ groups for sodium polyacrylate or sulfo and carboxy
(
ethyl)phosphine oxides [8]).
groups for heparin (Scheme 2).
–
+
+ Na + Br–
+
–
COO Na +
(
A)
+N
–COO–
+N
–Br
–
3
+
Na+ + Br–
+
–
SO Na +
(B)
–
+N
–SO3 +N
–Br
–
COOH +
+ H + Br–
+
(
C)
+N
–COO–
+N
–Br
Scheme 2. Polyelectrolyte reactions of ionenes with sodium polyacrylate (A) and heparin (B, C).
DOKLADY CHEMISTRY Vol. 465
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288
MIKHAILENKO et al.
η
sp/С
D
1.0
0.3
0.2
0.1
2
1
a
0.5
b
0
1
2
3
4
5
, dL/g
C
Fig. 1. Reduced viscosity (20°C) of aqueous solutions of
ionenes ( IIIa and ( IIIb vs. concentration.
0
1
2
z
a)
b)
Fig. 2. Turbidimetric titration curves of solutions of (
1)
Mixing of aqueous solutions of ionene IIIa and
sodium polyacrylate at pH 9.5 and ( ) heparin at pH 5.0
2
with an ionene solution (sample IIIa, Table 1). The conꢀ
centration of solutions of sodium polyacrylate, heparin,
heparin or polyacrylic acid (as the sodium salt, pH 9.5)
was found to result in the formation of insoluble stoꢀ
ichiometric polyelectrolyte complex, as confirmed by
the results of turbidimetric titration of aqueous soluꢀ
tions of sodium polyacrylate (pH 9.5) or heparin with
an aqueous solution of ionene IIIa (Fig. 2). In both
cases, precipitation of insoluble stoichiometric polyꢀ
electrolyte complex was already noticed at the ionꢀ
and ionene is 0.0015 baseꢀmol/L.
referred to unity; = [ionene] : [sodium polyacrylate]
heparin).
D is the absorbance
z
(
lyte complex with polyacrylic acid is dissolved only
partly, whereas the complex with heparin remains
insoluble even with a fourfold excess of ionene (Fig. 2).
This distinguishes the phosphorusꢀ and nitrogenꢀconꢀ
taining ionenes IIIa and IIIb from known ionenes
based on aliphatic amines and azoles, because in the
latter cases, waterꢀsoluble nonꢀstoichiometric polyꢀ
electrolyte complexes are formed, no matter whether
the blocking polyelectrolyte (ionene) or the lyophilizꢀ
ing polyelectrolyte (sodium polyacrylate or heparin) is
taken in excess [7, 13]. Probably, the difference is due
ene/sodium polyacrylate or heparin ratio (
than 0.3; the maximum precipitation corresponded to
= 0.7–0.8 in the case of flexibleꢀchain polyacrylate
polyanion and = 1.2–1.3 in the case of rigidꢀchain
heparin polyanion. In this case, reflects the ratio of
z) of more
z
z
z
the ionene and the polyanion calculated in relation to
the contents of positively charged (for ionene) and
negatively charged groups (COO– for sodium polyꢀ
−
acrylate or SO3 and CОO– for heparin) in the reacꢀ to higher hydrophobicity of phosphorusꢀ and nitroꢀ
tants. When there is excess of the polycation (z
> 1) in genꢀcontaining ionenes caused by the presence of
the reaction mixture, the stoichiometric polyelectroꢀ phenyl side groups in the molecule. As a consequence,
Table 1. Reaction of bispyridylphosphine oxide (I) with 1,4ꢀdibromobutane (60°C, 24 h)
(
CH ) Ph
(CH ) Ph
2
2
2 2
+
+
N
(CH2)2 P (CH2)2
N + Br(CH2)4Br
N
(CH ) P (CH2)2
N (CH2)4
2 2
–
Br
–
Br
O
I
O
n
IIIa, IIIb
Elemental analysis* (found), %
Pyridylphosphine
oxide I, mmol
1,4ꢀDibromobutane,
Ionene
(yield), %
EtOH, mL
mmol
C
H
Br
N
P
0
.6
.6
0.6
0.6
2.2
1.0
IIIa (38)
IIIb (51)
54.68
55.03
6.54
6.32
27.52
29.57
5.13
5.04
4.60
4.43
0
*
Calculated for C H Br N OP, %: C, 53.81; H, 5.73; Br, 27.54; N, 4.83; P, 5.34.
26 33 2 2
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SYNTHESIS AND PROPERTIES OF A NEW FAMILY
289
Table 2. Reaction of trispyridylphosphine oxide (II) with 1,4ꢀdibromobutane*
–
+
N
Br
N
(
CH ) Ph
(CH ) Ph
2 2
2
2
+
+
Br(CH ) Br
2
4
N
(CH2)2 P (CH2)2
N
(CH )
N
(CH ) P (CH2)2
N
2 4
2 2
O
II
–
Br
O
–
Br
IV
Elemental analysis*** (found), %
Pyridylphosphine 1,4ꢀDibromobꢀ
Ionene**
(yield), %
Run
oxide II, mmol
utane, mmol
C
H
Br
N
P
1
2
0.6
0.6
0.5
0.6
0.6
0.9
IVa (34)
IVb (29)
IVc (43)
IVd (35)
45.33
43.94
45.21
43.53
5.56
5.46
5.52
5.31
38.15
40.57
39.70
41.18
5.76
5.47
5.58
4.67
4.24
4.05
4.17
3.61
3****
0.75
1.2
4
*
The reaction was carried out at 60°C for 24 h in ethanol (1 mL).
*
* Swelling ratio in H O: 2.3, 1.8, 3.9, and 12.8 for IVa, IVb, IVc, and IVd, respectively.
2
*
*
** For C H Br N OP, anal. calcd. (%): C, 47.05; H, 5.26; Br, 36.14; N, 6.10; P, 4.49.
25 32 3 3
*** A mixture of EtOH (0.5 mL) and DMF (1 mL) was used as the solvent.
the insoluble complex is formed even at a relatively oxides with dibromobutane gave linear (waterꢀsoluble)
large excess ( 0.3) of the lyophilizing agent (polyꢀ and crossꢀlinked (limitedly water swelling) phosphoꢀ
z
≥
anion) and there is no region of existence of a nonꢀstoꢀ rusꢀ and nitrogenꢀcontaining polycations (ionenes).
ichiometric polyelectrolyte complex with an excess of The ability of linear ionenes to be involved in reactions
blocking agent (polycation).
with negatively charged polyelectrolytes (in particular,
heparin and polyacrylic acid) to give waterꢀinsoluble
polyelectrolyte complexes gives hope for subsequent
application of these compounds as heparin antagoꢀ
nists. The synthesized crossꢀlinked ionenes are promꢀ
ising ion exchange resins and sorbents [3] and can also
be used as polymer hydrogels in medicine and agriculꢀ
ture [3].
The results indicate that ionenes of type III can
bind heparin into polyelectrolyte complex, which is,
moreover, waterꢀinsoluble (Scheme 2). Owing to this
feature, the ionenes we synthesized could be used in
the future to neutralize the anticoagulating action of
heparin and to control in this way blood coagulation
properties [7, 14].
Tris(pyridyl)phosphine oxide
(
II
)
(prepared
Synthesis of bis[2ꢀ(4ꢀpyridyl)ethyl]phenylethꢀ
beforehand from red phosphorus and 4ꢀvinylpyridine ylphosphine oxide (I). Styrene (1.38 g, 13.3 mmol) was
[
(
15]) reacts with 1,4ꢀdibromobutane on heating added dropwise at 56–58
°C over a period of 0.5 h to a
C, 24 h) in ethanol to give phosphorusꢀ and nitroꢀ mixture of bis[2ꢀ(4ꢀpyridyl)ethyl]phosphine oxide
60°
genꢀcontaining ionenes IV, which are insoluble in (2.3 g, 8.8 mmol), KOH (0.67 g, 12.0 mmol), DMSO
organic solvents and in water and evidently have a (20 mL), water (0.18 mL), and hydroquinone (0.01 g).
threeꢀdimensional network structure. The structure The reaction mixture was heated (56–58°C) for addiꢀ
proposed for ionenes IV was also confirmed by eleꢀ tional 8 h, cooled, diluted with water, extracted with
mental analysis data (Table 2). The yields (29–43%) chloroform, and dried with potassium carbonate.
and the swelling ratios in water (1.8–12.8) of ionenes Chloroform and DMSO were evaporated and the resꢀ
IVa–
IVd depend little on the initial reactant ratio idue was dried in vacuum to give 1.65 g (52% yield) of
(
Table 2) and the solvent nature (Table 2, no. 3).
bis[2ꢀ(4ꢀpyridyl)ethyl]phenylethylphosphine oxide
), white crystals, Tm = 192 (from ethyl acetate).
(
I
°C
Ionenes IVa–IVd are hygroscopic light pink powꢀ
ders. The IR spectra of IVa
–IVd exhibit characteristic
For С H N OP anal. calcd. (%): C, 72.51; H, 6.91;
N, 7.69; P, 8.50.
22
25
2
absorption bands of the phosphine oxide P=O group
–1
centered at 1166 cm and for the pyridinium ring at
Found (%): C, 72.34; H, 6.79; N, 7.74; P, 8.65.
–1
1
516, 1599, and 1637 cm .
1H NMR,
δ
, ppm (CDCl ): 1.82 (m, 4H, CH P),
Thus, polyquaternization of bis[2ꢀ(4ꢀpyridyl)ethyl]ꢀ
phenylethylꢀ and tris[2ꢀ(4ꢀpyridyl)ethyl]phosphine 1.93 (m, 2H, CH
3
2
P), 2.74 (m, 6H, СН
СН Р), 6.91
2
2
2
DOKLADY CHEMISTRY Vol. 465
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290
MIKHAILENKO et al.
(
5
d, 4H, Py, CH=C, 3JHH = 5.5 Hz), 7.01–7.13 (m,
M − Mp
h
Ksw
=
,
H, Ph), 8.34 (d, 4H, Py, CH=N, 3JHH = 5.5 Hz). C
13
Mp
NMR,
2
δ
, ppm (CDCl ): 26.67 (СН Py, 2JСP = 2.2 Hz),
3 2
where Mh is the swollen hydrogel mass and Mp is the
7.45 (СН Ph, 2JСP = 3.0 Hz), 28.82 (d, PyСН СН Р, dry polymer mass.
2 2 2
1JСP = 63.4 Hz), 29.86 (d, PhСН СН Р, 1JСP 62.9 Hz),
1
The interpolymer reactions of the ionenes were
studied using commercial heparin, Spofa (Czechia)
(30% content of acid groups and acid number of
2
2
22.97 (СН=C, Py), 126.44 (Cp), 127.70 (Сm), 128.52
(
С
о), 139.94 (d, С , JCP = 12.1 Hz), 149.18 (d, CH=
i 3
C
Р,
,
8
1.3 mg/g) and nonꢀfractionated polyacrylic acid
Py, 3JCP = 13.3 Hz), 149.75 (CH=N). P NMR,
31
δ
sample with MM 170000. The formation of interpolyꢀ
mer complexes was studied by turbidimetric titration
using a KFKꢀ2 photocolorimeter.
–1
ppm (CDCl ): 45.7. IR (KBr, cm ): 1165 (P=O).
3
Synthesis of ionenes IIIa and IIIb. A solution of
bis[2ꢀ(4ꢀpyridyl)ethyl]phenylethylphosphine oxide (
I)
(
0.21 g, 0.6 mmol) and 1,4ꢀdibromobutane (0.13 g,
REFERENCES
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1
.6 mmol) in 2.2 mL of ethanol for ionene IIIa and in
.0 mL of ethanol for ionene IIIb was heated in a
1
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sealed ampoule under argon (60°C, 24 h). The reacꢀ
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31
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IVd. A solution of tris[2ꢀ(4ꢀpyridyl)ethyl]phenylethꢀ
ylphosphine oxide (II) and 1,4ꢀdibromobutane in
1
mL of ethanol was heated in a sealed ampoule under
argon (60°C, 24 h) (for reactant ratios, see Table 2).
The product was precipitated with acetone (25 mL)
and the ionene precipitate was washed with acetone
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Shaikhudinova, S.I., Malysheva, S.F., Kozlova, G.V.,
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994, no. 9, pp. 37–39.
,
(
3
×
25 mL) and dried in vacuum to a constant weight
1
to give ionenes IVa IVd in 34, 29, 43, and 35% yields,
–
9
. Trofimov, B.A., Andriyankova, L.V., Shaikhudinova, S.I.,
Kazantseva, T.I., Mal’kina, A.G., Zhivet’ev, S.A., and
Afonin, A.V., Synthesis, 2002, no. 7, pp. 853–855.
respectively, as light pink powders insoluble in organic
solvents and swelling in water, mp (dec.) 280–290°C.
The data of IR spectra and elemental analysis are given
above.
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0. Saucedo, A.S.A., Hagenbach, A., and Abram, U.,
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Bis[2ꢀ(4ꢀpyridyl)ethyl]phosphine oxide and tris[2ꢀ
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and purified according to procedures reported in [11]
(
and [15], respectively. 1,4ꢀDibromobutane (Merck) 12. Gusarova, N.K., Arbuzova, S.N., and Trofimov, B.A.,
Pure Appl. Chem., 2012, vol. 84, no. 3, pp. 439–459.
was used as the quaternization agent. IR spectra were
1
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no. 6, pp. 426–429.
measured on a Specord IRꢀ75 instrument. The H,
13
31
C, and P NMR spectra were recorded on a Bruker
4
1
00DPX spectrometer (400.13, 100.62, and
61.98 MHz, respectively) using HMDS as an internal
1
4. Efimov, V.S., Men’shova, G.I., and Gulyaeva, Zh.G.,
Farmakol. Toksikol., 1978, vol. 41, no. 4, pp. 409–413.
standard and 85% H PO as an external standard. The
3
4
15. Gusarova, N.K., Trofimov, B.A., Malysheva, S.F.,
Arbuzova, S.N., Shaikhudinova, S.I., Dmitriev, V.I.,
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viscosity of aqueous solutions of polymers was deterꢀ
mined on an Ubbelohde viscometer at 20°C. The
swelling ratio of the crossꢀlinked ionenes in water was
determined by gravimetric method and calculated by
the formula
,
1
Translated by Z. Svitanko
DOKLADY CHEMISTRY Vol. 465
Part 2
2015