Study of thermochemical properties of diphenyl[dialkyl(alkyl) carbamoylmethyl]phosphine oxides

Article abstract of DOI:10.1134/S107036321111003X

The synthesis and the studies of properties of diphenyl[dialkyl(alkyl) carbamoylmethyl]phosphine oxides by differential scanning calorimetry, mass spectrometry and Knudsen effusion method were performed. The thermodynamic parameters of melting and vaporiz

Full text of DOI:10.1134/S107036321111003X

ISSN 1070-3632, Russian Journal of General Chemistry, 2011, Vol. 81, No. 11, pp. 2231–2234. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © B.I. Petrov, G.A. Abakumov, A.V. Arapova, E.V. Sharova, O.I. Artiushin, I.L. Odinets, N.M. Lazarev, Yu.A. Bessonova, 2011,
published in Zhurnal Obshchei Khimii, 2011, Vol. 81, No. 11, pp. 1778–1781.
Study of Thermochemical Properties
of Diphenyl[dialkyl(alkyl)carbamoylmethyl]phosphine
Oxides
B. I. Petrova, G. A. Abakumova, A. V. Arapovaa, E. V. Sharovab,
O. I. Artiushinb, I. L. Odinetsb, N. M. Lazarevc, and Yu. A. Bessonovaa
a Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences,
ul. Tropinina 49, Nizhnii Novgorod, 603950 Russia
e-mail: bip@iomc.ras.ru
b Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences,
ul. Vavilova 28, Moscow, 119991 Russia
c Lobachevskii Nizhny Novgorod State University, pr. Gagarina 23, Nizhny Novgorod, 603950 Russia
Received October 7, 2010
Abstract—The synthesis and the studies of properties of diphenyl[dialkyl(alkyl)carbamoylmethyl]phosphine
oxides by differential scanning calorimetry, mass spectrometry and Knudsen effusion method were performed.
The thermodynamic parameters of melting and vaporization were calculated.
DOI: 10.1134/S107036321111003X
Currently, the development of materials for organic
light-emitting diodes (OLED) is an important task for
molecular electronics and applied synthetic chemistry.
The lanthanide complexes with organic ligands, in our
view, are most suitable for such application, since they
possess electroluminescent properties, as has been
shown previously [1].
with ligands of this type are needed the data on the
thermal behavior of the parent ligands, such as
enthalpy and entropy of melting and vaporization, and
the composition of the vapor phase, fragmentation of
the compounds under electron impact, etc.
We synthesized compounds I and III by amidation
of ethyl diphenylphosphorylacetic acid in alcohol
solution at room temperature.
The luminescence intensity of lanthanide ions
increases sharply at the formation of complexes with
organic ligands of a specific type [2]. To date, among
the derivatives of rare earth metals the best results at
the use as electroluminescent materials in OLED-
devices showed β-diketonate, carboxylate, pyrazo-
lonate, and hydroxyquinolinate complexes. The search
for new organic ligands for lanthanide complexes for
constructing OLED-devices has been limited by the
use of oxygen- and nitrogen-containing compounds.
However, more recently was found that high
electroluminescent activity posess the complex of
terbium with phosphorus-containing imidodiphos-
phinate ligands Tb[Ph2P(O)NP(O)Ph2]3 [3]. As another
type of promising phosphorus ligands can act diphenyl
[dialkyl(alkyl)carbamoylmethyl]phosphine oxides of
general formula Ph2P(O)CH2C(O)NR1R2. For the
targeted synthesis of new rare-earth metal complexes
Ph2P(O)CH2C(O)OEt + H2NAlk
→ Ph2P(O)CH2C(O)NHAlk,
I, III
(III).
Alk = i-Bu (I),
N
O
Synthesis of compound Ph2P(O)CH2C(O)N(Bu)2
(II) was carried out using Arbuzov reaction of ethyl
esters of trivalent phosphorus with chloroacetamide:
Ph2P(OEt) + ClCH2C(O)N(Bu)2
→ Ph2P(O)CH2C(O)N(Bu)2.
II
The compounds I–III were obtained in 70–90%
yield. They are stable in air, light colored fine-
2231

2232
PETROV et al.
complexes and the fusion thermodynamic parameters
(Fig. 1, Table 1).
Mass-spectrometric investigation. Analysis of the
mass spectra showed that the composition of the vapor
molecules corresponds to the chemical formula
Ph2P(O)CH2C(O)NR1R2. At the ionization by electrons
the compounds I–III exert similar fragmentation. The
main peaks and relative intensities of ions in the mass
spectra are shown in Table 2.
Vapor pressure. The temperature dependence of
the vapor pressure of the complexes (Fig. 2) was
measured by the Knudsen effusion method with the
registration of sublimed substance by weight in the
temperature range 100–216°C. The dependence is
expressed by the equation: log [p (mm Hg)] = AB/T.
The coefficients are listed in Table 3. From the P–T
plot were calculated the thermodynamic parameters of
sublimation and evaporation (Table 4). The tempera-
Т, °С
Fig. 1. DSC curves of the compounds I–III.
crystalline materials. Their structure was confirmed by
elemental analysis, IR and NMR spectroscopy. The
solubility of compounds in organic solvents are quite
different [4, 5].
Differential scanning calorimetry. The study of
phase transitions of the samples I–III in the range of
30–300°C was performed using a differential scanning
calorimeter DSC204F1 of Netzsch Geratebau,
Germany. The design of the calorimeter DSC204F1
and working procedure are similar to the described in
[6]. Checking the reliability of the calorimeter was
performed using standard calibration experiments to
measure the thermodynamic characteristics of melting
of n-heptane, mercury, indium, tin, lead, bismuth and
zinc. As a result, it was found that the apparatus and
the measurement technique provide ability of
measuring the temperature of physical transformations
with an accuracy ±0.2 K, the enthalpies of transitions
±1%. Calorimetric measurements for the complexes
were carried out in an argon atmosphere at a heating
rate of 5 K min–1. Within the sensitivity of the method
the studied substance is an individual phase. In this
temperature range the samples underwent only one
phase transformation, the melting. From the data of
differential scanning calorimetry (DSC) of compounds
I–III were found the melting temperatures of the
Table 2. Major peaks and relative ion intensities in the mass
spectra of compounds I–III
Ion
Ph2P(O)CH2C(O)NHBui
Irel, %
[Ph2P(O)]+
[Ph2P(O)CH2]+
88
65
[Ph2P(O)CH2C(O)]+
92
[Ph2P(O)CH2C(O)NH]+
[Ph2P(O)CH2C(O)NHC]+
Ph2P(O)CH2C(O)NHBui
100
51
93
Ph2P(O)CH2C(O)NBu2
[Ph2P(O)]+
[Ph2P(O)CH2]+
[Ph2P(O)CH2C(O)]+
64
100
79
Ph2P(O)CH2C(O)NBu2
39
Ph2P(O)CH2C(O)NH(CH2)3
N
O
[Ph2P(O)]+
[Ph2P(O)CH2]+
[Ph2P(O)CH2C(O)]+
52
91
87
Table 1. Standard thermodynamic parameters of the melting
process of compounds I–III
[Ph2P(O)CH2C(O)NHCH2]+
100
Comp. no. mp, °С ΔHmelting, kJ mol–1 ΔSmelting, J mol–1 K–1
[Ph2P(O)CH2C(O)NH(CH2)2]+
71
41
165
80
29.7
30.2
41.7
67.9
85.7
93.3
I
Ph2P(O)CH2C(O)NH(CH2)3
N
II
III
174
O
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 11 2011

STUDY OF THERMOCHEMICAL PROPERTIES
ture range of vaporization was chosen according to the
2233
Т, °С
DSC data. In the studied temperature range no
processes except vaporization observed. In addition,
according to the data of mass spectrometry, at the
heating does not occur association of molecules, so the
calculation of the vapor pressure of sublimation and
evaporation was carried out assuming formation of
monomeric vapor.
EXPERIMENTAL
N-Isobutylcarbamoylmethyldiphenylphosphine oxide
(I) [4] and N,N-dibutylcarbamoylmethyldiphenylphos-
phine oxide (II) [5] were prepared by the described
methods. Their physical and chemical constants coin-
cide with published data.
103/Т, K–1
Fig. 2. Plots of the saturated vapor pressure of the
complexes I–III log [p, (mm Hg)] = f (103/T): (1) I, (2) II,
(3) III.
2-(Diphenylphosphoryl)-N-[3-(2-oxopyrrolidin-
1-yl)propyl]acetamide (III) was prepared as
described in [4] by direct amidation of ethyl diphenyl-
phosphorylacetic acid with 1-(3-aminopropyl)pyrro-
lidin-2-one in EtOH. Yield 75%. 31P NMR spectrum
(121.5 MHz, CDCl3), δP, ppm: 29.7. 1H NMR
spectrum (300 MHz, CDCl3), δ, ppm (J, Hz): 1.58
measured masses 50–990, electron energy 70 eV,
heating rate 100°C per minute.
Vapor pressure. The vapor pressure of compounds
was measured by the Knudsen effusion method with
the registration of weight of the sublimed substance.
The vapor pressure values were calculated using the
Hertz–Knudsen equation:
3
quintet (2H, (O)CNHCH2CH2, JHH = 6.9); 1.97
3
quintet (2H, C(O)CH2CH2, JHH = 7.7); 2.34 quintet
3
3
(2H, C(O)CH2, JHH = 7.7); 3.16 t (2H, NCH2, JHH
=
6.8), 3.17 t (2H, NCH2, 3JHH = 6.8), 3.26 t (2H, NCH2,
3JHH = 7.1), 3.30 d (2H, PCH2, JPH = 12.9), 7.42–7.50
2
Δm
σ τ
eff
T
М
m (5H, CHAr + NH), 7.50–7.56 m (2H, CHAr), 7.70–
7.78 m (4H, CHAr). IR spectrum (KBr, ν, cm–1): 510,
527, 730, 1120, 1176 (P=O), 1289, 1317, 1435 (CH2
def), 1544, 1666 (C=O), 2910, 2943, 2965 , 3060,
3277. Found, %: C 65.41, H 6.58, N 7.38.
C21H25N2O3P. Calculated, %: C 65.61, H 6.56, N 7.29.
,
р = 17.14
√
where p is the measured vapor pressure, mm Hg; Δm is
the amount of evaporated substance, g; σeff is the area
of the effusion hole, cm2 (σeff = 1.46×10–3 cm2); τ is the
evaporation duration, s, T is the evaporation tem-
perature, K, and M is molecular weight of the vapor.
Sensitivity of the McBain balances was 1.0156 g per
1 cm of the cathetometer KM-8 scale.
Mass-spectrometry. The mass spectra of
compounds were registered on a Polaris Q/Trace GC
Ultra gas chromatography-mass spectrometer. The
temperature of the ion source 250°C, the range of the
Table 4. Thermodynamic parameters of the process of
vaporization of the complexes I–III
Table 3. Coefficients of the equation: log [p, (mm Hg)] =
AB/T, for compounds I–III
Comp.
ΔHtr (T*),a
kJ mol–1
ΔStr (T*),a
J mol–1 K–1
276.5±10.7
Comp. no.
А
В, 10–3
R2 а
Process
ΔТ, °С
no.
Sublimation
126–160
144.8±4.4
I
17.32±0.56
12.97±0.44
11.88±0.45
7.56±0.23
5.56±0.18
6.06±0.21
0.997
0.997
0.996
I
Vaporization 102–160
106.5±3.4
193.2±8.4
II
II
Vaporization 170–214
116.0±4.0
172.3±8.6
III
III
a T* is the middle point of the studied temperature range.
a R2 is the confidence factor of the approximation.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 11 2011

2234
PETROV et al.
Bailey, N.J., Cowley, A., and Chippindale, A.M.,
ACKNOWLEDGMENTS
Synthetic Metals, 2000, vol. 7, p. 111.
4. Artyushin, O.I., Sharova, E.V., Odinets, I.L, Lene-
vich, S.V., Morgalyuk, V.P., Tananaev, I.G., Pribylo-
va, G.V., Myacoedova, G.V., Mastryukova, T.A., and
Myasoedov, B.F., Izv. Akad. Nauk, Ser. Khim., 2004,
no. 11, p. 2395.
5. Medved’, T.Ya., Chmutova, M.K., Nesterova, N.P.,
Koiro, O.E., Kochetkova, N.E., Myasoedov, B.F., and
Kabachnik, M.I., Izv. Akad. Nauk SSSR, Ser. Khim.,
1981, no. 9, p. 2121.
This work was supported by the Program of
Presidium of Russian Academy of Sciences, (project
no. 18).
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