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5ИЗЫСКАНИЕ ФИЗИОЛОГИЧЕСКИ АКТИВНЫХ СОЕДИНЕНИЙ МОЧЕВИНЫ С
МОНОХЛОРУКСУСНОЙ КИСЛОТОЙ
Абдурахманов Улугбек Курганбаевич Холбоев Юсубжон Хакимович
Андижанский государственный медицинский институт
Визуально политермическим методом изучена растворимость в системе мочевина -монохлоруксусная кислота - вода от -16,5 0С до 80,0 0С и на основе политерм растворимости бинарных систем и внутренных разрезов построена политермическая диаграмма системы. На политермической диаграмме растворимости разграничены поля кристаллизации льда, мочевины, монохлоруксусной кислоты (моногидрата и безводной) и соединений CO(NH2)2 • CICH2COOH, CO(NH2)2 • 2CICH2COOH.
Ключевые слова: политерма растворимости, мочевина, монохлоруксусная кислота,
монохлорацетат мочевины, дихлорацетат мочевины.
SEARCH FOR PHYSIOLOGICALLY ACTIVE UREA COMPOUNDS WITH MONOCHLOROACETIC ACID
The solubility in the system urea - monochloroacetic acid - water from -16.5 0С to 80.0 0С was studied visually by the polythermal method, and a polythermal diagram of the system was constructed based on the solubility polytherms of binary systems and internal sections. On the polythermal solubility diagram, the fields of crystallization of ice, urea, monochloroacetic acid (monohydrate and anhydrous) and compounds CO(NH2)2 • CICH2COOH, CO(NH2)2 • 2CICH2COOH.
Keywords: solubility polytherm, urea, monoloroacetic acid, urea monoloroacetate, urea dichloroacetate.
MOCHEVINANING MONOXLORSIRKA KISLOTA BILAN FIZIOLOGIK FAOL
BIRIKMALARINING TADQIQI Vizual politermik usul bilan Mochevina - monoxlorsirka kislota - suv sistemasining -16,5 0C dan 80,0 0C oralig'idagi eruvchanligi o'rganildi. Binar sistemalar eruvchanlik diagrammasi va ichki kesimlar asosida sistemaning politermik diagrammasi tuzildi. Politermik eruvchanlik diagrammasida muz, karbamid, monoxlorosirka kislotasi (monohidrat va suvsiz) va CO(NH2VClCH2COOH, CO(NH2^2ClCH2COOH tarkibli birikmalarning kristallanish sohalari aniqlandi.
Kalit so'zlar: eruvchanlik politermasi, mochevina, monoxlorsirka kislotasi, monoxlorasetat mochevina, dixlorasetat mochevina.
As is known, when plants are treated with solutions of derivatives of halocarboxylic acids and urea, the latter exhibit growth-stimulating and defoliating activity [1]. The preparation of various compounds based on them is of great importance in the synthesis of new defoliants.
To characterize the behavior of the initial components, with their joint presence in a wide concentration and temperature range, the system urea - monochloroacetic acid - water was studied from the temperature of complete freezing (-16.5 °C) to 80 °C [2].
The binary systems urea - water and monochloroacetic acid - water, which are part of the system under study, have been studied by a number of authors [3-10]. The data obtained by us are consistent with the literature.
According to [5], the solubility curves of monochloroacetic acid in water at temperatures from 26 to 56.5 °C consist of a crystallization branch of monochloroacetic acid. By studying this system in a wide temperature and concentration range, we have established the presence of a branch of crystallization of ice, monohydrate, and anhydrous monochloroacetic acid in its solubility diagram. The cryohydrate point corresponds to 60.3% monochloroacetic acid at -14.3°C.
On the melting diagram of the urea-monochloroacetic acid system, liquidus lines of the initial components and compounds of compositions CO(NH2)2^ClCH2COOH and CO(NH2)2^ClCH2COOH /164/ were revealed, which is also confirmed by our data.
Solubility in the system urea - monochloroacetic acid - water was studied using ten internal cuts. Of these, I - VSH are drawn from the side of monochloroacetic acid - water, to the top of CO (NH2) 2, and IX and X - from the side of urea - monochloroacetic acid to the top of H2O.
Based on the data obtained, a polythermal diagram was built solubility of the ternary system CO(NH2)2 - ClCH2COOH - H2O, on which the fields of crystallization of ice, urea, monochloroacetic acid (monohydrate and anhydrous) and compounds CO(NH2)2 • CICH2COOH, CO(NH2)2 • 2C1CH2COOH are demarcated. (Fig. 1.). The fields converge at four triple nodal points of the system, for which the crystallization temperatures and equilibrium solution compositions are determined. The characteristics of the double and triple points of the system urea -monochloroacetic acid - water are given in table 1.
On the polythermal solubility diagram, solubility isotherms are plotted every 10 °C. The projections of polythermal solubility curves on the corresponding lateral water sides of the system are constructed.
Analysis of the solubility diagram showed that the detected urea compounds with monochloroacetic acid are congruently soluble in water, since the rays of urea mono- and dimonochloroacetate, connecting the pole of the compounds with the origin, cross the fields of their crystallization in a wide temperature range.
cichjcooh \iacc.W
Macc.%
Fig.1. Solubility polytherm of the system urea - monochloroacetic acid - water
The compound CO(NH2)2 • 2CICH2COOH is formed in the temperature range -16.5 - 37.4 0C at a content of 30.2-82.3% monochloroacetic acid and 2.8 - 30.8% urea.
The compound CO(NH2)2 • CICH2COOH is formed starting from -13.9 °C and 13.6% concentration of monochloroacetic acid when the latter is introduced into a system saturated with urea.
The compounds were isolated in crystalline form and identified by chemical, X-ray, derivatographic and IR spectroscopic methods of physicochemical analysis.
Chemical analysis of isolated compounds from their supposed crystallization region gave the
Compound Found, % Calculated, %
С H N C H N
CO(NH2)2'ClCH2COOH 23,01 4,83 18,21 23,30 4,50 18,10
CO(NH2)2'2ClCH2COOH 24,22 4,33 11,38 24,10 4,10 11,20
Table 1
Double and triple nodal ^ points of the system urea - monochloroacetic acid - water
The composition of the й s
liquid phase, wt.% л h U а
M M fs S и a U Solid phase
Я z 0 и О 'Ü N
0 К Я "03
и и 5«
и ¡У
и
17,8 82,2 - 36,6 QCH2COOH + CO(NH2)2'2ClCH2COOH
9,1 74,7 16,2 6,0 - " -
7,7 73,6 18,7 1,6 QCH2COOH + CO(NH2)2'2ClCH2COOH + ClC^COOH'^O
- 73.6 26.4 3.5 QCH2COOH + ClCH2COOH«H2O
2.9 62.2 34.9 -12.2 ClC^COOH-HO + CO(NH2)2'2ClCH2COOH
2.8 60.7 36.5 -16.5 Ice + ClCH2COOH«H2O + CO(NH2)2'2QCH2COOH
- 60,3 39,7 -14,3 Ice + QCH2COOH
4,9 53,3 41,8 -11,1 Ice + CO(NH2)2'2ClCH2COOH
8,0 44,3 47,7 -9,0 - " -
12,0 37,6 50,4 -8,8 - " -
30,8 69,2 - 37,4 CO(NH2)2'2ClCH2COOH + COtN^b'ClC^COOH
25,4 61,3 13,3 12,6 - " -
22,5 49,6 27,9 0,9 - " -
21,4 44,1 34,5 -1,8 - " -
20,0 38,6 41,4 -4,6 - " -
17,4 30,2 52,4 -9,1 Ice + CO(NH2)2'2ClCH2COOH + COtN^b'ClC^COOH
18,3 28,8 52,9 -0,1 Ice + CO(NH2)2'ClCH2COOH
26,6 19,0 54,4 -10,8 - " -
34,1 13,6 52,3 -13,9 Ice + CO(NH2)2'ClCH2COOH + CO(NH2)2
34,0 13,2 52,8 -13,8 Ice + CO(NH2)2
31,9 - 68,1 -11,2 - " -
37,6 16,2 46,2 -7,0 CO(NH2)2'ClCH2COOH + CO(NH2)2
39,2 21,9 38,9 -1,8 - " -
40,9 28,5 30,6 3,2 - " -
41,4 32,9 25,7 6,6 - " -
41,8 37,4 20,8 10,8 - " -
41,0 48,5 10,5 22,0 - " -
40,4 59,6 - 45,4 - " -
X-ray phase analysis has established that the following set of diffractolines with the value of interplanar distances is typical for the compound CO(NH2)2*ClCH2COOH (d): 5,0; 4,71; 4,12; 3,99; 3,69; 3,61; 3,57; 3,27; 3,20; 2,94; 2,86; 2,55; 2,47; 3,36; 2,14; 2,07; 1,98; 1,78; 1,75 A and for CO(NH2)2'2ClCH2COOH: 4.89; 4.52; 3.96; 3.73; 3.35; 3.08; 3.01; 2.92; 2.87; 2.48; 2.37; 2.21; 2.15; 1.94; 1.81; 1.68; 1.66; 1.63; 1.53 A, which indicates the individuality of the isolated compounds (Fig.2).
The thermal properties of the obtained compounds differ significantly from those of the initial components [11].
It has been established that when heated, in an air atmosphere, the compound CO(NH2)2*ClCH2COOH melts congruently without decomposition. On the DTA curve, this process corresponds to an endothermic effect at 45.4 °C (Fig.3). At temperatures above 150 °C, the mass decreases sharply (TG = 26.6%), which is accompanied by a significant release of heat (an exothermic effect with a maximum at 205 °C). Further heating of urea monochloroacetate causes its stepwise decomposition at 265 and 325 °C. The weight loss in this case is 21.0 and 53.0%, respectively.
On the differential heating curve CO(NH2)2*2ClCH2COOH the melting process corresponds to an endothermic effect at 40.6° C (Fig.3). When heated, above the melting point, the compound decomposes with the release of heat (exothermic effect with a maximum at 190 ° C), which corresponds to a weight loss of 40%, Further
«- 9
Fig.2. Radiographs: 1.CO(NHi)i; 2.CICH2COOH; 3.CO(NHi)i • CICH2COOH;
4.co(nhi)2 • 2QCH2COOH
decomposition of the compound is endothermic in nature (thermal effects with minima at 275 and 325 ° C). Decomposition ends at 425 °C.
Figure 4 shows the IR spectra of urea, monochloroacetic acids and compounds based on them. In the IR spectrum of urea, the Vs (NH2)2 and Vas (NH2)2 absorption bands correspond to
vibrations at 3360 and 3460 sm-1. In the region of carbonyl absorption, the intense band at 1675 cm" 1 belongs to the v(CO) group. The absorption band Vs(CN) and 5(NH2) is respectively observed at 1015, 1075 and 1625 sm"1, and Vas(CN) 1470 sm"1.
In the IR spectrum of monochloroacetic acid, the vibration frequency v(CO) was found at 1735 cm"1, and the out-of-plane bending vibrations 5(OH) and v(C-Cl) were found at 948 and 650660 sm-1, respectively.
In the spectrum of urea monochloroacetate - CO(NH2)2*ClCH2COOH, the agreement band at 1735 sm-1, characteristic of the v(CO) group of the carboxyl free acid, disappears. Instead, two bands appear at 1315 and 1555 sm-1, due to respectively symmetric and antisymmetric stretching vibrations of the ionized COO- group, which indicates the participation of the latter in the formation of salt bonds. A decrease in the value of the v(C-Cl) vibration frequency by 65-70 sm-1 indicates the participation of the chlorine atom in the formation of a new hydrogen bond with the NH2 group of urea.
In the range of frequencies of stretching vibrations of N - H bonds, a wide agreement line. The spectrum in this region is blurred due to the nonequivalence of amino groups. The band at 3470 sm-1 is assigned to the antisymmetric stretching vibrations of the N - H bonds, and the frequency of 3350 sm-1 is due to the stretching symmetric vibrations of these bonds. The band of symmetric stretching vibrations vs(NH) is slightly shifted to the low-frequency region, which indicates the participation of the - (NH2) group in the formation of new hydrogen bonds.
Fig.3. Derivatograms: 1) CO(NH2)2'ClCH2COOH, 2) CO(NH2)2'2ClCH2COOH, 3) QCH2COOH
The stretching vibrations of the amide CO group in the spectrum of urea monochloroacetate include an absorption band with a maximum at 1640 sm-1; compared to the free urea molecule, it is shifted to the low-frequency region, which is caused by the elongation of this bond as a result of the protonation of the oxygen of the amide group.
100
-1——I——1_1——*———j._- t-1-1-1-1-1-1— I-i—,—I—___I
4000 3600 3200 2 BOO 2000 1600 1200 BOO 700 600 500 400
v, sm-1
Fig.4. IR spectra: 1 - CO(NH2)2, 2 - QCH2COOH, 3 - CO(NH2^C1CH2COOH
4 - CO(NH2)2^2C1CH2COOH
In the IR spectrum, urea bis-monochloroacetate to stretching vibrations the frequencies of 1640 sm-1 are assigned to the amide CO group, and the bands at 3335-3380 and 3490 sm-1 are assigned to the Vs(NH) and Vas(NH) groups. The frequencies of 1320 and 1560 sm-1 are due to the stretching symmetric and antisymmetric vibrations of the ionized (COO-) group, and 1725 sm-1 v(CO) of the non-ionized carboxyl group. This indicates that two molecules of monochloroacetic acid are not equivalent in the compound CO(NH2)2*2ClCH2COOH.
Two absorption bands are observed in the range of stretching vibration frequencies of the bindings (C-Cl). Band at 660 sm-1 assigned to stretching vibrations
bonds (C-Cl) that are not involved in specific interaction with the urea molecule, and the frequency with a maximum of 615 sm-1 is due to the stretching vibration of (C-Cl) bonds involved in the formation of new hydrogen bonds with the NH2 group of urea.
Thus, according to IR spectroscopic analysis, it has been established that the bond between urea and monochloroacetic acid in urea monochloroacetate and bis-monochloroacetate is carried out due to the protonation of oxygen from the CO group of urea and hydrogen bonding.
BIBLIOGRAPHY
1. Абдурахманов У. К., Холбоев Ю. Х. Фазовые равновесия в водных системах из трихлорацетата и тиомочевины //Universum: химия и биология. - 2020. - №. 9 (75). - С. 8082.
2. Абдурахманов У. К. Синтез дефолиантов на основе карбамида, тиокарбамида, аммиака, 2-хлорэтилфосфоновой, фосфорной, моно-и трихлоуксусных кисл : дис. - Ташкент. : Автореф. дис... канд. хим. наук, 1991.
3. Абдурахманов У. К. Физико-химическое изучение процесса образования 2-хлорэтилфосфоната мочевины //Universum: химия и биология. - 2021. - №. 5-2 (83). - С. 4550.
4. Абдурахманов У. К. Физико-химическое изучение системы из мочевины, фосфорной кислоты и монохлорацетата //Экономика и социум. - 2020. - №. 11. - С. 410-416.
5. Справочник по растворимости /Отв. ред. В.В.Кафаров. -М. -Л.: АН СССР, 1961. - Т. I. - Кн. I. - 960 с.
6. Торпуджиян М.К., Бойко В.Ф., Бергман А.Г. Политерма растворимости в системе борная кислота - мочевина - вода /Журн. неорг. химии. - Т. 2. - № 12. -С. 2807-2812.
7. Сулайманкулов К., Бергман А.Г. Политерма тройной системы вода - мочевина -сульфат аммония /Журн. неорг. химии. -1967. - Т. 2. - № 9. - С. 2226-2230.
8. Политерма растворимости в системе мочевина - глицин - вода /Д.А.Амилова, Б.С.Закиров, Х.Кучаров, Б.М.Беглов //Узб.хим.журнал. - 1984. - № 2. - С. 66-67.
9. Политерма растворимости в системе мочевина - лейцин - вода /Б.С.Закиров, Д.А.Амилова, Х.Кучаров, Б.М.Беглов //Докл. АН УзССР. - 1984. - № 10. - С. 32-33.
10. Политерма растворимости системы мочевина - метионин - вода /Б.М.Беглов, Д.А.Амилова, Б.С.Закиров, Х.Кучаров //Докл. АН УзССР. - 1984. - № 9. - С. 35-36.
11. Сулайманкулов К. Соединения карбамида с неорганическими солями. - Фрунзе: Илим, 1971. - 224 с.
