Synthesis of 2-(diphenylphosphoryl)phenyl ethers of ethylene glycols and structure of their sodium and potassium complexes

Article abstract of DOI:10.1134/S1070363216040186

Phase-transfer catalysis and template assembly on sodium and cesium cations were used to prepare 2-(diphenylphosphoryl)phenyl ethers of ethylene glycols Lⁿ with varied number of polyether units (n = 3–8). Previously unknown dinitro and disulfo

Full text of DOI:10.1134/S1070363216040186

ISSN 1070-3632, Russian Journal of General Chemistry, 2016, Vol. 86, No. 4, pp. 865–875. © Pleiades Publishing, Ltd., 2016.
Original Russian Text © I.S. Ivanova, I.N. Polyakova, V.E. Baulin, E.N. Pyatova, E.S. Krivorot’ko, A.Yu. Tsivadze, 2016, published in Zhurnal Obshchei
Khimii, 2016, Vol. 86, No. 4, pp. 679–689.
Synthesis of 2-(Diphenylphosphoryl)phenyl Ethers
of Ethylene Glycols and Structure of Their Sodium
and Potassium Complexes
I. S. Ivanovaa,b, I. N. Polyakovaa, V. E. Baulinb,c,
E. N. Pyatovaa,b, E. S. Krivorot’kob, and A. Yu. Tsivadzeb
a Kurnakov Institute of General and Inorganic Chemistry, Leninskii pr. 31, Moscow, 119991 Russia
e-mail: isivanova@mail.ru
b Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Moscow, Russia
c Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Moscow oblast, Russia
Received November 2, 2015
Abstract—Phase-transfer catalysis and template assembly on sodium and cesium cations were used to prepare
2-(diphenylphosphoryl)phenyl ethers of ethylene glycols Ln with varied number of polyether units (n = 3–8).
Previously unknown dinitro and disulfo derivatives of 2-(diphenylphosphoryl)phenyl ethers of di- and
triethylene glycols were synthesized. Complexes [NaL4]NCS·C6H6, [NaL4]ClO4, [KL5]NCS, and [KL5]ReO4
were synthesized, and their crystal structure was studied. Structure–stability constant correlations were found
for alkali metal complexes with phosphoryl podands Ln and isodentate crown ethers.
Keywords: 2-(diphenylphosphoryl)phenyl ethers of ethylene glycols, phosphoryl podands, phase-transfer
catalysis, template effect, complex-forming capacity, stability constants of complexes
DOI: 10.1134/S1070363216040186
Crown ethers and their acyclic analogs (podands)
are traditionally considered as organic ligands for binding
alkali metals [1]. Phoshoryl podands, specifically, 2-
(diphenylphosphoryl)phenyl (L1–L5) and 2-[(diphenyl-
phosphoryl)methyl]phenyl (Lig1–Lig5) ethers of ethylene
glycols [2], are quite efficient complex-forming agents
for alkali metals. The stability constants of some
lithium, sodium, and potassium complexes of these
compounds are comparable to corresponding values of
isodentate crown ethers or exceed them [2]. It was
found that the efficiency of interaction of Ln and Lign
with alkali metal cations depends on the length of the
polyether fragment n [2, 3] (Scheme 1).
Figure 1 shows the plots of the stability constants
(Kstab) of the M+L complexes of phosphoryl podands
L1–L5 with alkali metal 2,4-dinitrophenolates (log KM
)
+
in a THF–chloroform mixture (4 : 1 by volume)
against the number of ethylene glycol units [2].
Comparison shows that the highest stability constants
Scheme 1.
n O
n O
O
O
O
O
P
P
O
O
Ph
Ph
Ph
Ph
P
P
Ln (n = 1_8)
Ph
Ph
Ph
Lign (n = 1_5)
Ph
865

866
IVANOVA et al.
phenol (1а) with dichloro derivatives of tetra-, penta-,
hexa-, hepta-, and octaethylene glycols in a two-phase
NaOHsolid–dioxane system. We found that the yield of
phosphoryl podands L4–L8 decreases as n increases,
and the lowest yield (43%) was obtained with
octaethylene glycol L8 (Scheme 2).
The synthesis in a water-free two-phase Cs2CO3(s)–
dioxane system (8–12 h, 100°С) gave better results:
compounds Ln (n = 4–8) were obtained in a 80–90%
yield. It is quite possible that the substantial increase of
the yield of compounds L4–L8 with Cs2CO3 used as a
base is associated with the effect of template assembly
of the polydentate ligand, which increases with
increasing size of the cation. Evidence for this assump-
tion comes from the fact that addition of anhydrous
CsNO3 increases the yield of the synthesis of
compound L5 in the NaOH(s)–dioxane system to 75%.
The 31Р NMR spectrum of the reaction mixture in
the synthesis of compound L5 displays two singlets
(Δδ = 0.08 ppm) assignable to L5 and its Cs+ complex.
After the reaction mixture was treated with HCl, one
singlet disappeared from the spectrum. However, after
an analytical sample of compound L5 was refluxed in
dioxane in the presence of anhydrous Cs2CO3, the
spectrum again showed two signals.
Phosphoryl podands L3–L6 were also prepared by
an alternative procedure, namely, by reactions of
tosylate 2 with ethylene, diethylene, triethylene, and
hexa-ethylene glycols, respectively. In doing so, as
bases we used NaH in the synthesis of a triethylene
glycol derivative L3 and anhydrous Сs2CO3 in the
synthesis of ligands L4, L5, and L6, which have longer
polyether chains.
n
Fig. 1. Plot of log K against n.
among sodium and potassium complexes are
characteristic of the complexes with podands L4 and
L5, respectively. Unlike what is observed with the
lithium and sodium complexes, the stability constants
of the complexes with larger cations (K, Rb, and Cs)
steadily increase with increasing polyether chain
length in the phosphoryl podand.
Compounds L1–L5 were first synthesized in yields
of 66–81% by the reactions of 2-(diphenylphosphoryl)-
phenol (1а) with ditosylates of the corresponding
polyethylene glycols in the presence of sodium hydride
in anhydrous dioxane at 100°С [4]. As shown in [5], if
phenol 1а is alkylated in an anhydrous Cs2CO3–
dioxane system, the reactive triethylene glycol
ditosylate can be replaced by a synthetically more
accessible 1,8-dichloro-3,6-dioxaoctane; in this case,
the yield of compound L3 increases to 94%.
We failed to obtain nitrogen-containing podands
L2N, L3N, and L2S by alkylation of 4-nitro- and 4-sulfo-
2-(diphenylphosphoryl)phenols 1b and 1c with di- and
Aimed at optimizing the procedure of synthesis of
ethylene glycol ethers L4–L8, in the present work we
have studied the alkylation of 2-(diphenylphosphoryl)-
Scheme 2.
TsO
n O
P
O
P
OH
O
а, b
c, d
O
O
O
O
100°C, 16 h
P
P
n = k + 1
Ph
Ph
Ph
Ph
Ph
Ph
Ph
L4_L8
Ph
1a
2
а, NaOH(s)–dioxane, Cl(CH2CH2O)kCH2CH2Cl, L4 (60%), L5 (55%), L6 (51%), L7 (54%), L8 (43%); b, Cs2CO3(s)–dioxane,
Cl(CH2CH2O)2CH2CH2Cl, L4 (90%), L5 (90%), L6 (83%), L7 (87%), L8 (80%); c, Cs2CO3(s)–dioxane, HO(CH2CH2O)nH,
L4 (59%), L5 (69%), L6 (88%); d, Cs2CO3, HO(CH2CH2O)2H, MW (30 W), dioxane, 30 min, L4 (87%).
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SYNTHESIS OF 2-(DIPHENYLPHOSPHORYL)PHENYL ETHERS
Table 1. Elemental analyses of compounds L3–L8, L2N, L3N, and L3S
867
Found, %
Н
Calculated, %
Н
Compound
Formula
С
Р
С
Р
L3
L4
L5
L6
L7
L8
L2N
L3N
L3S
71.95
70.68
69.87
68.73
68.20
67.49
64.05
63.62
55.50
5.78
5.85
5.98
6.09
6.35
6.42
4.48
4.70
4.10
8.64
8.81
7.79
7.35
6.94
6.51
8.13
7.72
6.51
C42H40O6P2
71.79
70.77
69.86
69.05
68.33
67.67
64.17
63.64
55.63
5.74
8.82
8.30
7.83
7.42
7.05
6.71
8.27
7.81
6.83
C44H44O7P2
5.94
C46H48O8P2
6.12
C48H52O9P2
6.28
C50H56O10P2
C52H60O11P2
C40H34N2O9P2
C42H38N2O10P2
C42H38Na2O12P2S2
6.42
6.55
4.58
4.83
4.22
triethylene glycol ditosylates in the presence of NaH or
Cs2CO3 in dioxane or DMF. Nothing but the starting
materials was isolated from the reaction mixture. The
same result was obtained if the syntheses were
performed under MW radiation (Scheme 3).
diffraction (XRD) analysis (Table 3) and IR
spectroscopy (Table 4).
The vibration frequencies in the IR spectra of
ligands L4 and L5 and complexes 5 and 6 (Table 3)
were assigned based on the structural and spectral data
for neutral podands with diphenylphosphoryl (Ln) [6]
and diphenylphosphorylmethyl (Lign) terminal groups
[7, 8], as well as for their alkali metal complexes [5, 9–12].
Nonetheless, we managed to prepare 4-nitro
derivatives L2N and L3N by the nitration of phosphoryl
podands L2 and L3 with a mixture of 60% nitric and
98% sulfuric acids at room temperature. The yields of
L2N and L3N were 40 and 50%, respectively. Sulfo
derivative L2S was prepared as a disodium salt by
treatment of compound L3 with 98% sulfuric acid at
80°С (Tables 1, 2).
The IR spectra of complexes 3 and 4 contain a
strong ν(Р=О) band at 1181 cm–1, which is shifted red
by 11 cm–1 from the high-frequency component of the
ν(Р=О) band in the spectrum of ligand L4 (Table 4).
The ν(РhО) band is shifted blue (by 10 and 7 cm–1,
respectively) from the corresponding band in the
spectrum of ligand L4. The coordination of K+
decreases the ν(Ph–O) frequency in the spectrum of
[KL5]NCS by about 6 cm–1 from the corresponding
band in the spectrum of ligand L5. The positions of the
ν(P=O) and νas(COC) bands remain almost unchanged.
As mentioned above, the highest Kstab values among
sodium and potassium complexes with ligands Ln are
characteristic of those with n = 4 and 5, respectively
(Fig. 1). We isolated crystalline complexes
[NaL4]NCS·C6H6 (3), [NaL4]ClO4 (4), [KL5]NCS (5),
and [KL5]ReO4 (6) and studied their structure by X-ray
Scheme 3.
n O
P
OH
P
O
P
n O
O
а
b, c
O
O
O
O
O
P
R
P
R
R
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
Ph
L2N, L3N, L2S
1b, 1c
L2, L3
а, Cs2CO3, Ts(OCH2CH2)nOTs, dioxane, 100°C; b, HNO3, H2SO4, 25°C; c, H2SO4, 80°C. R = NO2 (1b, L2N, L3N), SO3Na
(1c, L2S); n = 2 (L2N), 3 (L3N, L2S).
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 86 No. 4 2016

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IVANOVA et al.
1
Table 2. Н and 31Р NMR spectral data for compounds L3–L8, L2N, L3N, and L3S
δН, ppm (J, Hz)
Compound
δР, ppm
solvent
СDCl3
ОСН2ОСН2
3.20 m (4Н), 3.30 s (4Н), 3.90 m 6.90 m (2Н), 7.08 m (2Н), 7.45 m (14Н), 7.90 26.92
(4Н) m (10Н)
3.23 m (4Н), 3.36 m (4Н), 3.94 m 6.86 m (2Н), 7.01 m (2Н), 7.37 m (14Н), 7.83 27.04
Ar–H
L3
L4
CDCl3
CDCl3
CCl4
(4Н)
m (10Н)
L5
4.08 m (4Н), 4.48 m (4Н)
6.90 m (2Н), 7.09 m (2Н), 7.49 m (14Н), 7.80 28.90
m (10Н)
L6
3.12 m (4Н), 3.38 m (12Н), 3.81 m6.80 m (2Н), 7.00 m (2Н), 7.32 m (14Н), 7.64 22.71
(4Н) m (8Н), 7.81 m (2Н)
L7
CCl4
3.18 m (4Н), 3.39 m (20Н), 3.81 m6.79 m (2Н), 7.00 m (14Н), 7.67 m (8Н), 7.81 22.60
(4Н) m (2Н)
L8
CDCl3
3.22 m (4Н), 3.37 m (4Н), 3.48 m 6.88 m (2Н), 7.08 m (2Н), 7.44 m (14Н), 7.78 26.80
(4Н), 3.56 m (16Н), 3.92 m (4Н) m (10Н)
L2N
L3N
L3S
DMSO-d6 + CCl4 3.00 m (4Н), 3.85 m (4Н)
7.28 m (2Н), 7.50 m (14Н), 7.68 m (6Н), 8.38 43.02
d (2Н, 3JHH = 7.5), 8.70 d (2Н, 3JHP = 16.0)
DMSO-d6 + CCl4 3.20 m (4Н), 3.30 s (4Н), 3.91 m 7.30 m (2Н), 7.50 m (14Н), 7.75 m (6Н), 8.43 d 42.92
(4Н)
(2Н, 3JHH = 7.5), 8.73 d (2Н, 3JHP = 16.0)
DMSO-d6 + CCl4 3.12 m (4Н), 3.29 s (4Н), 4.90 m 7.00 m (2Н), 7.50 m (14Н), 7.70 m (6Н), 7.85 41.51
(4Н)
d (2Н, 3JHH = 7.5), 8.16 d (2Н, 3JHP = 16.0)
We previously showed that the formation of complexes
[Na2(μ-L2)(CH3CN)I2] [9], [LiL3]ClO4·2С6Н6 [5],
[LiLig2](ClO4), and [LiLig2](NCS) [10] has almost no
effect onν(Р=О) and ν(РhО).
The ν(С≡N) bands of the outer-sphere NCS– ions
in the spectra of [NaL4]NCS·C6H6 and [KL5]NCS are
observed at 2057 and 2060 cm–1. The strong band at
1099 cm–1 in the spectrum of [NaL4]ClO4 is associated
with stretching vibrations of the outer-sphere ClO4–,
and the δ(СlO4–) bending vibration band is observed at
623 cm–1. The ReO4– anion of [KL5]ReO4 gives a strong
stretching vibration band at 907 cm–1.
According to XRD data, the complex ions [NaL4]+
complex ions in compounds 3 and 4 have similar
structures (Figs. 2, 3). The [NaL4]+ ion in complex 4 is
located on the crystallographic axis and in complex 3,
on the two-fold pseudoaxis passing through the Na and
О4 atoms.
Na+ cation is coordinated to all the seven oxygen
atoms in ligand L4 (Table 5). Five ethylene glycol
oxygens are nearly coplanar, and the P=O oxygens lie
on opposite sides of this plane. Note that a similar
environment is characteristic of the Na+ cation in
[Na(18K6)(H2O)]+, where one of the oxygen atoms of
the crown ligand and the water molecule deviate
oppositely from the mean plane of the other five
macrocycle oxygens. The bonds of Na+ with the P=O
groups in complexes 3 and 4 have close lengths and
are the shortest, like in other complexes with P=O-
containing podands. The bonds of Na+ with the anisole
and ether О atoms in complex 3 are appreciably longer
than in complex 4 (2.499–2.838 and 2.454–2.699 Å,
respectively), and the Na1–O3 bond is unusually long
(2.747 Å) for a bond with ether oxygen. The Na+
environment in [NaLig3]I·С2Н5OH [11] is formed by
the Lig3 hexadentate ligand which has the same S
shape as in the free state [8]. The two Na+ cations in
[Na2(μ-L2)(CH3CN)I2] [9] are bridged with each other
by two P=O oxygen atoms of podand L2. The podand
bound bidentately to one Na+ cation and tetradentately
to the other. One of the anisole oxygens is not involved
in coordination with sodium. The environments of both
The ethylene glycol chain between the anisole
oxygens (О2 and О6 in complex 3; O2 and О2а in
complex 4) of phosphoryl podand L4 has a С-shaped
configuration resembling a fragment of the 18-crown-6
molecule in [Na(18-crown-6)(H2O)]NCS [13]. The
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SYNTHESIS OF 2-(DIPHENYLPHOSPHORYL)PHENYL ETHERS
869
Table 3. Main crystal data and details of data collection and structure refinement for complexes 3–6
Parameter
3
C51H50NNaO7P2S
905.91
4
C44H44ClNaO11P2
869.17
5
C47H48KNO8P2S
887.96
6
C46H48KO12P2Re
1080.08
Formula
M
T, K
174(2)
150(2)
174(2)
180(2)
Crystal system
Space group
Z
Triclinic
Orthorhombic
Fdd2
Monoclinic
C2/c
Monoclinic
C2/c
–
P1
2
8
4
4
a, A
12.339(3)
12.803(3)
18.146(4)
104.290(3)
96.551(4)
118.189(3)
2357.5(9)
1.276
37.3326(18)
13.4407(6)
16.4280(8)
90
18.990(6)
20.806(7)
13.266(4)
90
20.560(3)
19.320(3)
14.065(2)
90
b, A
c, A
α, deg
β, deg
90
124.035(4)
90
126.683(2)
90
γ, deg
V, A3
90
8243.2(7)
1.401
4344(2)
4480.3(13)
1.601
dcalc, g/cm3
µMo, mm–1
Crystal dimensions, mm
Tmin, Tmax
θ range, deg
1.358
0.198
0.243
0.299
2.939
0.40×0.16×0.02
0.6004, 0.7454
2.171–26.765
0.24×0.12×0.04
0.6494, 0.7463
2.182–31.984
0.24×0.08×0.08
0.5597, 0.7452
2.588–25.457
0.20×0.10×0.04
0.6384, 0.7460
2.471–27.690
Number of reflections:
measured
22082
9999 [0.0501]
5674
22408
6699 [0.0398]
5077
14759
3997 [0.0752]
2581
21005
5260 [0.0480]
3866
unique (N) [Rint]
with I > 2σ(I) (No)
Number of refined parameters
R1, wR2 on No
586
268
273
295
0.0485, 0.0989
0.1106, 0.1201
0.987
0.0450, 0.0916
0.0711, 0.1028
1.039
0.0592, 0.1442
0.1044, 0.1701
1.001
0.0441, 0.0994
0.0689, 0.1096
1.019
R1, wR2 on N
S
Δρmax /Δρmin, e/Å3
0.364/–0.363
0.399/–0.370
0.657/–0.481
1.464/–0.980
Na+ cations include I–. In the former complex, the
acetonitrile nitrogen atom completes the environment
to coordination number 4, and in the latter complex,
the coordination number is 5.
oxygen atoms of different types (Table 6) is less
pronounced than between the Na–O or Li–O bond
lengths with podands Ln and Lign. In complexes 5 and
6, the longest K–O bond is formed with the anisole О2
atom (2.872 and 2.982 Å, respectively) and the
shortest bond is formed with the ether О4 (2.757 Å, 5)
or the phosphoryl (2.777 Å, 6) oxygen atom. Note that
the K–О bonds in complex 6 are slightly longer than in
complex 5. The central С-shaped fragment of podand
L5 includes only three ethylene glycol units between
the ether О3 and О3а atoms. The terminal units deviate
The crystals of [KL5]NCS (5) and [KL5]ReO4 (6)
are isostructural. The [KL5]+ complex cation (Fig. 4) is
located on the two-fold rotation axis passing through
K1 and the midpoint of the С23–С23а bond. The
environment of the K+ ion includes all oxygen atoms
of ligand L5. The difference in K–О bond lengths with
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870
IVANOVA et al.
Table 4. Assignment of the principal vibration frequencies (cm–1) in the IR spectra of ligands L4 and L5 and complexes 3–6
Assignment
ν(Ph)
L4
1587, 1581
1462
3
1588, 1578
1461
4
1592, 1577
1460
L5
1598
5
6
1588, 1575
1463
1588, 1575
1461
δ(CH2)
1462
ν(Р–Ph)
ω(СН2)
ν(Р–Ph)
ν(Ph–O)
ν(Ph=O)
δ( Ph)
1446
1443
1449
1439
1441
1444
1377, 1351
1275
1377, 1349
1287
1377, 1350
1282
1377, 1355
1280
1377, 1350
1280
1380, 1350
1297, 1279
1245, 1238
1182
1242
1252
1249
1252, 1241, 1230 1246, 1237
1192, 1179
1139
1181
1181
1183
1156, 1138
1115
1181
1134
1142
1137
1136
νas(COC)
ν(ClO4)
δ(Ph)
1119, 1107
–
1118, 1099
–
–
1111, 1089
–
1109
1099
–
–
1073
1080
1081
1071
1077
1088, 1078
1042
νs(COC) + ν(CC)
δ(Ph)
1050
1050
1045
1051
1041
996
998
997
996
996
998
ν(CO) + ν(CC) +
ρ(CH2) + ν(ReO4)
961, 947, 927, 959, 934, 869,
957, 928
946, 927, 877, 961, 917, 857,
962, 935,
907, 831,
907, 851, 830,
855, 831
860, 846
834
ν(РС)
δ(Ph)
798
803
798
798
800
798
767, 757, 736, 752, 719, 696
719, 699
753, 722,
715, 698
766, 752, 739, 760, 736, 720
716, 696
734, 719
δ(СОС)
δ(PhРО)
615
615
623
–
–
616
544, 523, 490
552, 534
553, 532
551, 544, 521, 551, 542, 499
487
550, 499
to the opposite sides so that the anisole, and more
especially phosphoryl oxygen atoms deviate signi-
ficantly from the mean plane of the crown-shaped
fragment. The structures of the potassium complexes
with dibenzo-24-crown-8 in the [K(di-benzo-24-
crown-8)DME]2С60·DME compound (С60 is fullerene
and DME is dimethoxyethane [14]) and with the 3,4'-
formation of two long K–О bonds with the DME
molecule. In complexes [K(R2-dibenzo-24-crown-8)]+
includes eight macrocycle oxygens and, in addition,
the carbonyl O atom of the R substituent of a neigh-
boring complex. The bonds with the carbonyl atoms
that bind the complexes into dimers are the shortest
among the K–О bonds (2.685 and 2.655 Å). In both
complexes, the K–О bonds with the anisole oxygens
(2.931–2.971 and 2.916–2.995 Å) are longer than with
the ether oxygens (2.732–2.843 and 2.743–2.821 Å).
In the crown-ether complexes, the K–О bond lengths
are comparable with those in complexes 5 and 6 with
the phosphoryl podand, even though the former have
higher coordination numbers.
R2-dibenzo-24-crown-8
and
4,4'-R2-dibenzo-24-
crown-8 molecules in two [K(R2-dibenzo-24-crown-
8)]2(PF6)2 compounds (R is methoxycarbonyl) [15]
have been previously reported. In these complexes, the
K+ cations are surrounded by the oxygen atoms of not
only the macrocycle but the DME molecule or the
carbonyl group of the R substituent as well. The
[K(dibenzo-24-crown-8) DME]+ structure is charac-
terized by the lack of bond between K+ and one of the
anisole О atoms (K···О 3.232 Å), overlapping ranges
of the K–О bond lengths with the ether (2.808–
2.831 Å) and anisole (2.799–2.904 Å) oxygens, and
It can be suggested that in solution [2], alkali metal
complexes with podands have the same structure as in
crystal. In this case, the XRD results explain why the
Kstab of the sodium podand complexes tend to decrease
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SYNTHESIS OF 2-(DIPHENYLPHOSPHORYL)PHENYL ETHERS
871
Fig. 2. Structure of the complex cation [NaL4]+ in complex
Fig. 3. Structure of the complex cation [NaL4]+ in complex
3 (in the terminal phenyl rings only carbons bound to
4 (in the terminal phenyl rings only carbons bound to
phosphorus are shown).
phosphorus are shown).
in the L4, Lig3, and L2 series. Complexes [NaL4]+ and
[NaLig3]+, where the ligands exhibit maximum
denticities (7 and 6), have high stability constants
(log K = 6.6 and 6.1, respectively). The low Kstab
(log K = 4.8) of the complex with podand L2 is
probably associated with the formation of binuclear
complexes like [Na2(μ-L2)(CH3CN)I2], where four of
the five oxygen atoms are involved in coordination
with two sodium cations.
(log K = 4.6 [2]) of the sodium complex of dibenzo-
21-crown-7, in which four of the seven oxygen atoms
are anisole oxygens. Measured under the same condi-
tions, the stability constants of the sodium complexes
Table 5. Bond lengths d in complexes [NaL4]NCS·C6H6 (3)
and [NaL4]ClO4 (4)
Bond
d, Å
3
Type of О atom
Na1–O1
Na1–O2
Na1–O3
Na1–O4
Na1–O5
Na1–O6
Na1–O7
2.3276(19)
2.7433(19)
2.747(2)
2.499(2)
2.585(2)
2.8375(19)
2.3184(19)
4
P=O
A similar correlation between structure and Kstab is
found for the lithium complexes with ligands L3, Lig3,
and Lig2. The involvement of all the six О atoms in Li
coordination in [LiL3]ClO4·2С6Н6 [5] is consistent
with its high Kstab value (log K 7.0). The Li cation in
[LiLig3]I·H2O [12] loses bonds with two anisole
oxygens, and, as a result, the Kstab of this complex is
lower (log K = 6.7). In isostructural compounds
[LiLig2](ClO4) and [LiLig2](NCS) [10], the podand
acts as a pentadentate ligand, but the Kstab of the
lithium complex with Lig2 is significantly lower (log K =
5.0) than with Lig3. This fact suggests that the con-
tribution of two anisole oxygen atoms of Lig2 into
stability is insignificant as compared to that of one
ether oxygen atom. Evidence for the weak effect of
anisole oxygens on stability is provided by low Kstab
Ph–O–C
C–O–C
C–O–C
C–O–C
Ph–O–C
P=O
Na1–O1
Na1–O2
Na1–O3
Na1–O4
2.328(2)
2.699(3)
2.461(2)
2.454(4)
P=O
Ph–O–C
C–O–C
C–O–C
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872
IVANOVA et al.
and ligand L5 (log K = 5.8) shows that the slight
increase of Kstab is explained by the involvement of the
anisole oxygen atoms of ligand L5 in K+ coordination.
Anisole oxygens only slightly affect Kstab, and the
increase in their number in dibenzo-24-crown-8
decreases the Kstab of the potassium complex with the
crown ether (log K = 5.3 [2]) with respect to that with
L5, even though these two ligands have the same
number of oxygen atoms.
Thus, efficient methods to synthesize phosphoryl
podands Ln (n = 3–8) and novel dinitro and disulfo
derivatives of 2-(diphenylphosphoryl)phenyl ethers of
di- and triethylene glycol are proposed. Sodium and
potassium complexes with complementary podands L4
and L5 were prepared, and their crystal structure was
studied. Analysis of the structure and stability
constants of alkali metal complexes with phosphoryl
podands Ln and isodentate crown ethers allows us to
conclude that the phosphoryl groups form strong bonds
with the Li+, Na+, and K+ atoms and play an important
role in the formation of stable complexes. The relative
contribution of the phosphoryl groups into the stability
of complexes decreases in the order Li+ > Na+ > K+
because of the equalization of the bond lengths of the
cations with the phosphoryl and ether oxygen atoms
and increased number of the ether oxygen atoms. The
anisole oxygen atoms only slightly contribute to the
stability of the complexes; however, this contribution
increases in the order Li+ < Na+ < K+.
Fig. 4. Structure of the complex cation [KL4]+ in complex 5
(in the terminal phenyl rings only carbons bound to
phosphorus are shown).
of ligand L4 and 18-crown-6, are equal (log K = 6.6)
[2]. In is evident that the contribution of three ether
and two P=O oxygens of ligand L4 is comparable with
that of six crown ether oxygens.
Structural data on potassium complexes of podands
Ln and Lign are unavailable in the literature.
Obviously, the increase of Kstab with elongation of the
ethylene glycol chain (Fig. 1) is associated with the
increasing number of ether oxygens. The XRD data for
complexes 5 and 6 showed that the K–О bonds with
the phosphoryl and ether oxygen atoms are close in
length. Consequently, these oxygen atoms almost
equally contribute into the stability of the complexes.
Comparison of the Kstab values of the potassium
complexes of 18-crown-6 (log K = 5.5 [16], 5.7 [17])
EXPERIMENTAL
The MW-assisted synthesis was performed in a
CEM Discover focused synthesizer equipped with
pressure and temperature gages. The reaction progress
and purity of products were monitored by thin-layer
chromatography on Silufol with iodine vapor
development. Column chromatography was performed
on silica gel L 100/160; eluents СHCl3 and СHCl3–i-
PrOH (20 : 1). The melting points were measured with
a shorte-scale Anschütz thermometer (no corrections
were applied). The 1H NMR spectra were measured on
Bruker-СPX-200 and Bruker-DXР-200 (200 MHz)
instruments against TMS (1Н) or 85% Н3РО4 (31P).
The IR spectra were run on a Bruker Vertex 70
spectrometer in the range 4000–400 cm–1 (for suspen-
sions in mineral oil). Elemental analysis was per-
formed on a Carlo Erba C,Н,N analyzer and a Thermo
Jarrell Ash IRIS Advantage inductively coupled
plasma spectrometer.
Table 6. K–O bond lengths (Å) in complexes [KL5]NCS (5)
and [KL5]ReO4 (6)
Bond
K1–O1
5
6
Type of O atom
P=O
2.765(3)
2.777(3)
K1–O3
K1–O4
K1–O2
2.841(3)
2.757(3)
2.872(3)
2.861(3)
2.809(4)
2.982(3)
C–O–C
C–O–C
Ph–O–C
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SYNTHESIS OF 2-(DIPHENYLPHOSPHORYL)PHENYL ETHERS
873
X-ray diffraction analysis of the crystals of
[NaL4]NCS·C6H6 (3), [NaL4]ClO4 (4), [KL5]NCS (5),
and [KL5]ReO4 (6) was performed at the Shared
Equipment Center, Kurnakov Institute of general and
Inorganic Chemistry, on a Bruker APEX-II CCD
automated diffractometer. The APEX2, SAINT, and
SADABS programs [18] were used for data collection
and processing. The structures were solved by the
direct method using SHELXS-2013/1 [19] (3, 4) and
SIR-92 [20] (5, 6) programs with the subsequent
calculation of difference Fourier syntheses.
(DMSO-d6 + CCl4), δ, ppm: 7.00 m (1Н, Ar-H), 7.50
m (6Н, Ar-H), 7.75 m (4Н, Ar-H), 8.25 d (1Н, Ar-H,
3
3JHH = 7.5 Hz), 8.58 d (1Н, Ar-H, JHР = 16.0 Hz),
11.00 s (1Н, Ar-OH). 31Р NMR spectrum (DMSO-d6 +
CCl4): δР 32.43 ppm. Found, %: С 63.50, 63.39; Н
4.05, 4.12; Р 8.74, 8.09. C18H14NO4P. Calculated, %: С
63.72; Н 4.16; Р 9.13.
Sodium
4-hydroxy-2-(diphenylphosphoryl)-
benzenesulfonate (1c). A mixture of 1.0 g (3.4 mmol)
of phenol 1а and 15 mL of 98% H2SO4 was stirred for
4 h at 80°С and then poured into 300 mL of saturated
NaCl solution. After 24 h, the precipitate was filtered
off, dried to constant weight (1.2 g), and recrystallized
from saturated Na2SO4 solution. Yield 0.85 g (63%),
The SCN– anion in complex 3 is disordered over
two roughly antiparallel orientations populated in the
0.63(1) : 0.37(1) ratio. The С and N atoms of the less
populated component were refined isotropically. The
С21 atom of the ethylene glycol chain is disordered
over two equally populated positions (С21А and С21В),
which were refined isotropically. The ReO4– anion in
complex 5 is disordered over two positions slightly
displaced from the rotation axis 2. The occupancy of
these positions [0.202(3) : 0.298(3)] was determined in
the refinement under the assumption that the rhenium
atoms have equal anisotropic thermal parameters. The
isotropic thermal parameters of oxygen atoms were
taken to be 1.5 of Ueq of Re, and the coordinates were
refined with geometrical constraints. All non-hydrogen
atoms in structures 3–6, except for those mentioned
above, were refined anisotropically. The H atoms were
refined using the riding model with Uiso(H) = 1.2Ueq(С).
The structure of compound 4 was refined as a racemic
twin [BASF = 0.19(8)]. The crystals of compounds 5
and 6 are isostructural. Refinement was performed
using the SHELXL-2014 program [19]. The main
crystal data and details of data collection and structure
refinement are presented in Table. 2. The crystal data
have been deposited at the Cambridge Structural
Database (CCDС nos. 1431015–1431018).
1
mp ≥300°С. H NMR spectrum (D2О), δ, ppm: 6.84–
7.44 m (11Н, Ar-H), 7.76 m (2Н, Ar-H). 31Р NMR
spectrum (D2О): δР 35.08 ppm Found, %: С 54.35,
54.69; Н 3.05, 3.12; Р 7.74, 7.89. C18H14NaO5PS.
Calculated, %: С 54.55; Н 3.56; Р 7.82.
1,8-Bis[2-(diphenylphosphoryl)phenoxy]-3,6-di-
oxaoctane (L3). Freshly calcined Cs2CO3, 3.26 g
(10.0 mmol), and 5.0 g (10.2 mmol) of compound 2
were added to a solution of 0.31 g (5.0 mmol) of
ethylene glycol in 25 mL of anhydrous dioxane. The
mixture was heated under reflux for 10 h and evapo-
rated in a vacuum. The residue was mixed with dilute
(1 : 2) HCl, and the mixture was extracted with СHCl3
(3 × 25 mL). The extract was washed in succession
with two 15-mL portions of dilute (1 : 1) HCl and
water (3 × 20 mL), and the solvent was evaporated in a
vacuum. The residue was chromatographed on a
column of silica gel (eluent СHCl3). Yield 1.7 g (48%),
mp 201–202°С (benzene–hexane, 1 : 1).
1,11-Bis[2-(diphenylphosphoryl)phenoxy]-3,6,9-
trioxaundecane (L4). a. A mixture of 3.0 g
(10.0 mmol) of phenol 1а, 0.4 g (10 mmol) of finely
ground NaOH, 1.2 g (5.0 mmol) of 1,11-dichloro-3,6-
dioxaoctane, and 25 mL of anhydrous dioxane was
stirred for 8 h at 100°С and then evaporated in a
vacuum. The residue was mixed with 50 mL of water,
and the mixture was extracted with СHCl3. The extract
was washed in succession with 30% NaOH (3 ×
10 mL), 15 mL of dilute (1 : 1) HCl, and water (3 ×
20 mL), and then the solvent was evaporated in a
vacuum. The residue was treated with 20 mL of diethyl
ether, and the precipitate was filtered off and
chromatographed on a column of silica gel (eluent
СHCl3). Yield 2.9 g (60%), mp 117–119°С (benzene–
hexane, 2 : 1).
2-(Diphenylphosphoryl)phenol (1а) and ethyl 2-[2-
(diphenylphosphoryl)phenoxy]toluenesulfonate (2) were
prepared as described in [21].
4-Nitro-2-(diphenylphosphoryl)phenol (1b). A mix-
ture of 1.0 g (3.4 mmol) of phenol 1а, 0.35 g (3.4 mmol)
of 60% НNO3, and 10 mL of 98% H2SO4 was stirred
for 4 h at 25°С and then poured into 100 mL of ice
water. The precipitate was filtered off, washed with
water on the filter until neutral washings, dried in a
vacuum dessicator over P2O5 to constant weight
(0.9 g), and recrystallized from anhydrous DMF. Yield
0.5 g (43%), mp 240–242°С. 1H NMR spectrum
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874
IVANOVA et al.
b. A mixture of 2.5 g (8.5 mmol) of phenol 1а, 2.9 g
and 5.0 g (10.2 mmol) of compound 2 (reaction time
18 h); the solvent was removed in a vacuum. Yield
3.5 g (85%), oily substance.
(9.0 mmol) of finely ground dry Cs2CO3, 1.3 g (4.3 mmol)
of 1,11-dichloro-3,6-dioxaoctane, and 30 mL of
anhydrous dioxane was stirred for 8 h at 100°С, and
dioxane was evaporated in a vacuum. The residue was
treated with 15 mL of dilute (1 : 1) HCl, and the
mixture was extracted with СHCl3 (2 × 15 mL). The
extract was washed with water (3 × 20 mL), and the
solvent was evaporated in a vacuum. The residue was
treated with 20 mL of diethyl ether, and the precipitate
was filtered off and chromatographed on a column of
silica gel (eluent СHCl3). Yield 3.8 g (90%).
1,20-Bis[2-(diphenylphosphoryl)phenoxy]-
3,6,9,12,15,18-hexaoxaeicosane (L7) was prepared by
the same procedure as L4 (method b) from 5.2 g
(17.7 mmol) of phenol 1а, 5.8 g (17.7 mmol) of dry
Сs2CO3 and 2.88 g (8.8 mmol) of 1,20-dichloro-
3,6,9,12,15,18- hexaoxaeicosane; reaction time 15 h.
Yield 6.72 g (87%), oily substance.
1,23-Bis[2-(diphenylphosphoryl)phenoxy])-
3,6,9,12,15,18,21-heptaoxatricosane (L8) was
prepared by the same procedure as L4 (method b) from
4.5 g (15.3 mmol) of phenol 1а, 5.0 g (15.3 mmol) of
dry Сs2CO3, and 3.1 g (7.7 mmol) of 1,23-dichloro-
3,6,9,12,15,18,21-heptaoxatricosane; reaction time
15 h. Yield 5.6 g (80%), oily substance.
c. By analogy with L3, from 0.53 g (5.0 mmol) of
diethylene glycol, 3.3 g (10.0 mol) dry Сs2CO3, and
5.0 g (10.2 mmol) of compound 2; reaction time 16 h.
Yield 2.2 g (59%).
d. A mixture of 0.5 g (0.50 mmol) of diethylene
glycol, 0.33 g (0.10 mol) of dry Сs2CO3, and 0.34 g
(1.0 mmol) of compound 2 in 6 mL of anhydrous
dioxane was placed into a laboratory system for
focused MW heating. The heating was performed for
0.6 h at 30 W, the maximum temperature was 130°С.
After cooling, the reaction mixture was poured into
100 mL of dilute (1 : 2) HCl and extracted with СHCl3
(3 × 30 mL). The extract was washed in succession
with two 15-mL portions of dilute (1 : 2) HCl and
water (3 × 20 mL), and the solvent was then evaporated
in a vacuum. The residue was chromatographed on a
column of silica gel (eluent СHCl3). Yield 0.33 g (87%).
1,5-Bis[4-nitro-2-(diphenylphosphoryl)phenoxy]-
3-oxapentane (L2N). A mixture of 1.0 g (1.6 mmol) of
compound L2, 0.33 g (3.2 mmol) of 60% HNO3, and
10 mL of 98% H2SO4 was stirred for 2 h at 50°С and
then diluted with 100 mL of water. The precipitate was
filtered off and dried. Yield 0.7 g (58%), mp 232–234°С
(DMF).
1,8-Bis[4-nitro-2-(diphenylphosphoryl)phenoxy]-
3,6-dioxaoctane (L3N) was prepared from 0.5 g
(0.7 mmol) of compound L3, 0.9 g (8.6 mmol) 60%
HNO3, and 10 mL of 98% H2SO4. Yield 0.3 g (51%),
mp 226–228°С (DMF).
1,14-Bis[2-(diphenylphosphoryl)phenoxy]-3,6,9,12-
tetraoxatetradecane (L5). а. By analogy with L4
(method b), from 4.0 g (13.6 mmol) of phenol 1а, 4.4 g
(13.6 mmol) of dry Сs2CO3, 1.9 g (6.8 mmol) of 1,14-
dichloro-3,6,9,12-tetraoxatetradecane, and 45 mL of
dioxane; reaction time 11 h. Yield 5.3 g (90%), oily
substance.
b. By analogy with L3, from 0.75 g (5.0 mmol) of
triethylene glycol, 3.3 g (10.0 mol) of dry Сs2CO3,
5.0 g (10.2 mmol) of compound 2, and 25 mL of dioxane;
reaction time 18 h. Yield 2.7 g (69%), oily substance.
4,4'-(Ethylenedioxy)bis(ethyleneoxy)]bis[sodium-
3-(diphenylphosphoryl)benzenesulfonate] (L3S). A
mixture of 0.5 g (0.7 mmol) of compound L3 and
10 mL of 98% H2SO4 was stirred for 3 h at 80°С and
then diluted with 100 mL of a saturated NaСl solution.
The precipitate was filtered off and dried. Yield 0.25 g
(40%), mp >300°С.
Complex [NaL4]NCS·C6H6 (3). Prefiltered solu-
tions of NaNCS and podand L4 in acetonitrile (Na : L =
2 : 1) were mixed at room temperature and left to stand
in air until a transparent film was formed. The film
was triturated with hexane and the resulting powder
was filtered off and recrystallized from a 1 : 1
methylene chloride–benzene mixture. Found, %: С
67.50, 67.39; Н 5.05, 5.12; Р 6.74, 6.59; S 3.45, 3.56.
C52H50NNaO7P2S. Calculated, %: С 67.61; Н 5.56; Р
6.84; S 3.54.
1,17-Bis[2-(diphenylphosphoryl)phenoxy]-
3,6,9,12,15-pentaoxaheptadecane (L6). а. By analogy
with L4 (method b), from 5.0 g (16.9 mmol) of phenol
1а, 5.5 g (16.9 mmol) of dry Сs2CO3, 2.71 g
(8.9 mmol) of 1,17-dichloro-3,6,9,12,15-pentaoxahepta-
decane, and 40 mL of dioxane; reaction time 15 h.
Yield 5.8 g (83%), oily substance.
b. By analogy with L3, from 1.0 g (5.0 mmol) of
tetraethylene glycol, 3.3 g (10.0 mol) of dry Сs2CO3,
Complex [NaL4]ClO4 (4). Solutions of NaClO4 in
a 1 : 1 methylene chloride–acetonitrile mixture and
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SYNTHESIS OF 2-(DIPHENYLPHOSPHORYL)PHENYL ETHERS
875
podand L4 in methylene chloride were mixed at room
temperature (Na : L4 = 1 : 1). The mixture was filtered
and left to stand in air until complete evaporation of
the solvents. The residue was triturated with hexane,
and the resulting powder was filtered off and
recrystallized from a 1 : 1 methylene chloride–benzene
mixture. Found, %: С 60.50, 60.39; Н 5.05, 5.12; Р
6.94, 7.09. C44H44ClNaO11P2. Calculated, %: С 60.80;
Н 5.10; Р 7.13.
5. Baulin, V.E., Ivanova, I.S., Polyakova, I.N., Pyato-
va, E.N., Krivorot’ko, E.S., and Tsivadze, A.Yu., Russ.
J. Gen. Chem., 2015, vol. 85, no. 4, p. 899. DOI:
10.1134/S1070363215040234.
6. Minacheva, L.Kh., Ivanova, I.S., Tsivadze A.Yu., and
Sergienko, V.S., Doklady Chem., 2001, vol. 377, no. 1,
p. 65. DOI: 10.1023/A:1018856106567.
7. Kireeva, I.K., Gorbunova, Yu.E., Ivanova, I.S.,
Baulin, V.E., Tsivadze, A.Yu., Mikhailov, Yu.N.,
Koord. Khim., 1997, vol. 23, no. 1, p. 853.
Complex [KL5]NCS (5). Solutions of KNCS in
absolute ethanol and podand L5 in methylene chloride
were mixed at room temperature (K : L5 = 1 : 1). The
mixture was filtered and left to stand in air until
complete evaporation of the solvents. The residue was
triturated with hexane, and the resulting powder was
filtered off and recrystallized from a 1 : 1 methylene
chloride–benzene mixture. Found, %: С 63.45, 63.39;
Н 5.35, 5.52; Р 6.94, 6.79. C47H48KO8P2Re. Cal-
culated, %: С 63.57; Н 5.45; Р 6.98.
Complex [KL5]ReO4 (6). Solutions of KReO4 in
DMSO and podand L5 in methylene chloride were
mixed at room temperature (K : L5 = 1 : 1) and left to
stand in air until complete evaporation of the solvents
to obtain transparent colorless crystals. Found, %: С
51.05, 51.10; Н 4.40, 4.32; Р 5.64, 5.70. C46H48KO12P2S.
Calculated, %: С 51.15; Н 4.48; Р 5.74.
8. Minacheva, L.Kh., Baulin, V.E., and Sakharova, V.G.,
Koord. Khim., 1995, vol. 21, no. 3, p. 236.
9. Minacheva, L.Kh., Ivanova, I.S., Kireeva, I.K.,
Baulin, V.E., Sakharova, V.G., Tsivadze, A.Yu., and
Sergienko, V.S., Russ. J. Inorg. Chem., 2000, vol. 45,
no. 8, p. 1184.
10. Polyakova, I.N., Ivanova, I.S., Baulin, V.E., and
Tsivadze, A.Yu., Crystallogr. Rep., 2015, vol. 60, no. 4,
p. 508. DOI: 10.1134/S1063774515040173.
11. Ivanova, I.S., Minacheva, L.Kh., Kireeva, I.K., Sakha-
rova, V.G., Tsivadze, A.Yu., and Porai-Koshits, M.A.,
Zh. Neorg. Khim., 1992, vol. 37, no. 10, p. 2185.
12. Minacheva, L.Kh., Ivanova, I.S., Kireeva, I.K.,
Sakharova, V.G., Tsivadze, A.Yu., and Porai-Koshits, M.A.,
Koord. Khim., 1993, vol. 19, no. 3, p. 185
13. Dobler, M.K., Dunits, J.D., and Seiler, P., Acta
Crystallogr., Sect. B, 1974, vol. 30, no. 11, p. 2741.
DOI: 10.1107/S056774087400793X.
14. Kozhemyakina, N.V., Nuss, J., and Jansen, M., Eur. J.
Inorg. Chem., 2009, p. 3900.
ACKNOWLEDGMENTS
15. Gibson, H.W., Wang, H., Bonrad, K., Jones, J.W.,
Slebodnick, C., Zackharov, L.N., Rheingold, A.L.,
Habenicht, B., Lobue, P., and Ratliff, A.E., Org.
Biomol. Chem., 2005, vol. 3, p. 2114. DOI: 10.1039/
B503072M.
The work was financially supported by the Russian
Foundation for Basic Research (project nos. 15-03-
02995 and 15-03-02635).
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