RU2803991C1 - Tetra-4-(3'-carboxyphenylsulphanyl)tetra-5-nitrophthalocyanine cobalt(ii) tetrasodium salt, having the properties of a homogeneous catalyst for oxidation of sodium diethyldithiocarbamate - Google Patents

Abstract

FIELD: catalysts.

SUBSTANCE: invention is related to production of new catalysts for oxidation of sulfur-containing compounds based on substituted cobalt(II) phthalocyanines, namely the tetrasodium salt of tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine cobalt(II) of the following formula:

EFFECT: proposed compound exhibits high catalytic activity in the oxidation of sodium diethyldithiocarbamate.

1 cl, 4 dwg, 2 ex

Description

The invention relates to the chemical industry, namely, to the production of new catalysts for the oxidation of sulfur-containing compounds based on substituted cobalt(II) phthalocyanines, specifically with tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine cobalt(II) tetrasodium salt, possessing the properties of a homogeneous catalyst for the oxidation of sodium diethyldithiocarbamate.

It is known to use a metal complex of cobalt(II) with tetra-4-(4'-carboxyphenylsulfanyl)phthalocyanine as a catalyst for the homogeneous oxidation of sulfur-containing compounds with atmospheric oxygen in alkaline solutions [Vashurin A., Kuzmin I., Mayzlish V., Razumov M., Golubchikov O ., Koifman O. Kinetics and mechanism of the oxidation of dithiocarbamic acids in the presence of Co(II) phthalocyaninetetacarboxylic acid // Journal of the Serbian Chemical Society. 2016. T. 81. No. 9. P. 1025-1036] formulas:

The closest structural analogue is the metal complex of tetra-4-(4'-carboxyphenylsulfanyl)-5-nitrophthalocyanine with cobalt(II) tetrasodium salt [Patent 2640414 Russian Federation, IPC B01J 31/22, C07F 15/06, C07D 487/22. Homogeneous catalyst for the oxidation of sodium diethyldithiocarbamate based on cobalt(II) tetra-4-(4'-carboxyphenylsulfanyl)-5-nitrophthalocyanine / Znoiko S.A., Vashurin A.S., Kuzmin I.A., Maizlish V.E., Shaposhnikov G.P. Applicant and patent holder Ivanov. state chem.-tech. univ. - 2017108304, application. 03/13/2017; publ. 01/09/2018 Bulletin. No. 1], formulas:

possessing solubility in water and aqueous-alkaline media.

The objective of the invention is to search for new compounds that exhibit high catalytic activity in the oxidation of sodium diethyldithiocarbamate.

The problem is solved by the metal complex of tetra-4-(3'-carboxyphenoxy)tetra-5-nitrophthalocyanine with cobalt(II) tetrasodium salt of the formula:

The structure of this compound was proven by elemental analysis, IR, and electron spectroscopy, MALDI-TOF spectrometry.

Thus, the IR spectra of the claimed compound contain bands characteristic of stretching vibrations of the corresponding functional groups: 1721 (-COOH); 1600 (NO ₂ ); 1334 (NO ₂ ); 1124 (CS) [Dyer JR . Application of absorption spectroscopy of organic compounds / Transl. from English Ivanova V.T. M.: Chemistry. 1970. 164 p.]. In the mass spectrum of the synthesized metal complex of tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine tetrasodium salt with cobalt(II), a signal of the target molecular ion with m/z = 1361 was detected.

Brief description of drawings:

In fig. 1 shows the MALDI-TOF mass spectrum of 4-(3'-carboxyphenylsulfanyl)-5-nitrophthalonitrile; in fig. 2 - IR spectrum of 4-(3'-carboxyphenylsulfanyl)-5-nitrophthalonitrile; in fig. 3 - MALDI-TOF mass spectrum of tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine cobalt (II) tetrasodium salt; in fig. 4 - EAS of tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine cobalt (II) tetrasodium salt in DMF (curve 1) and H ₂ SO ₄ (curve 2).

The invention makes it possible to increase the catalytic activity of the target product.

For the synthesis of the claimed compound, the following substances are used:

- DMF – GOST 20289-74

- potassium carbonate – GOST 4221-76

- 3-mercaptobenzoic acid – CAS 4869-59-4

- urea – GOST 2081-2010;

- cobalt chloride – GOST 5852-70;

- 4-(3-carboxyphenylsulfanyl)-5-nitrophthalonitrile. However, Since this compound is not commercially available, it was synthesized in the following manner:

Synthesis of 4-(3-carboxyphenylsulfanyl)-5-nitrophthalonitrile.

0.5 g (0.02 mol) of 4-bromo-5-nitrophthalonitrile 3 , 0.31 g (0.02 mol) of 3-mercaptobenzoic acid and 30 ml of DMF are charged into a round-bottomed flask equipped with a reflux condenser, stirrer and thermometer. 0.28 g (0.02 mol) of potash in 1 ml of water is added to the resulting solution. The mixture is kept with stirring and a temperature of 25 ° C for one hour. Then 20 ml of water and 1.5 ml of concentrated hydrochloric acid are slowly added to the reaction mass, and a precipitate forms, which is filtered and dried.

Yield: 0.57 g (65%). T _diff . = 219-221 °C.

^1H NMR spectrum, δ, ppm: 9.05 s (COOH, 1H), 8.66 s ( ^H1 , 1H), 8.18 s ( ^H2 , 1H), 8.08 d ( ^H6 , 1H), 8.03 m ( Н ³ , 1Н), 7.65 m (Н ⁴ , 2Н), 7.59 m (Н ⁵ , 1Н).

Found, %: C 55.11; H 2.31; N 12.86; S 9.78. C ₁₅ H ₇ N ₃ O ₄ S. Calculated, %: C 55.38; H 2.17; N 12.92; S 9.86;

MALDI-TOF, m/z: 325 [M] ⁺ . (Fig. 1)

IR (KBr), cm ^-1 : 2231 (C≡N); 1689 (C=O); 1558 (NO ₂ , ass.), 1342 (NO ₂ , sym.), 1172 (CS). (Fig. 2)

Example 1. Synthesis of tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine cobalt(II) tetrasodium salt.

A thoroughly stirred mixture of 0.33 g of 4-(3-carboxyphenylsulfanyl)-5-nitrophthalonitrile, 0.11 g (0.5 mmol) of cobalt chloride dihydrate and 60 mg (1 mmol) of urea was kept at a temperature of 195 °C until the reaction mixture solidified. Next, the reaction mixture is ground, washed with acidified water and acetone, then the compound is dried in air at 75 °C. The resulting powder is treated with a hot solution of sodium ethoxide in ethyl alcohol. The resulting blue-green solution is subjected to column chromatography on silica gel M60, eluting with DMF. Then the solvent is distilled off, the target product is dried in air at 75 °C.

Yield: 0.26 g (78%).

MALDI-TOF, m/z: 1361 [M + H] ⁺ . (Fig. 3)

IR (KBr), cm ^-1 : 1721 (-COOH); 1600 (NO ₂ ); 1334 (NO ₂ ); 1124 (CS).

Found, %: C 52.72; H 2.36; N 12.24; C ₆₀ H ₂₈ CoN ₁₂ O ₁₆ S ₄ ; Calculated, %: C 52.98; H 2.07; N 12.63; S 9.43.

ESP λ _max , nm: in DMF 675 (Fig. 4, curve 1); in H ₂ SO ₄ 772 (Fig. 4, curve 2).

Example 2. Use of a cobalt(II) complex with tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine tetrasodium salt as a homogeneous catalyst for the oxidation of N,N-carbomodithiolate.

Catalytic activity is assessed by the effective rate constant for the oxidation of sodium N,N-diethyldithiocarbamate (GOST 8864-71) with atmospheric oxygen at pH 7.6 and temperature 30°C (k). Oxidation is carried out at normal pressure in a metal batch reactor with a volume of 650 ml, equipped with a thermometer, a reflux condenser, a sampling outlet and a bubbler for supplying air at a speed of 2 l/min, ensuring the process proceeds in a kinetic mode. 600 ml of sodium N,N-diethyldithiocarbamate solution with a concentration of 0.1 g/l is loaded into the reactor. To determine the current concentration of sodium diethyldithiocarbamate, a 2 ml sample is transferred to a 25 ml flask and 4 ml of 0.02 N CuSO ₄ is added. A solution of copper sulfate is prepared using a reagent in accordance with GOST 19347-99. When copper sulfate is added to a collected sample, a thick, dark brown precipitate of copper complex is formed. The mixture is stirred for one minute. Then add 5 ml of chloroform and 2-3 drops of 50% acetic acid to the resulting solution and shake for 1.5 minutes. The copper complex of diethyldithiocarbamate is extracted into a layer of chloroform. The organic layer is transferred to a 25 ml volumetric flask, and the complex is extracted again from the remaining aqueous solution to improve the accuracy of the analysis. The collected copper complex solution is brought to the mark with chloroform. Take 2 ml of solution from this flask, transfer it to another 25 ml volumetric flask and again make up to the mark with chloroform. Using a spectrophotometer at a wavelength of 436 nm, the optical density of the solution is determined and the concentration of N,N-diethyldithiocarbamate is calculated based on the calibration line.

Kinetic parameters of the oxidation of sodium N,N-diethyldithiocarbamate ( c 2.6×10 ^-3 mol/l) in the presence of phthalocyanine catalysts with a concentration of 5.6×10 ^-5 mol/l were measured in an aqueous alkaline solution at pH = 11. The catalytic activity of the cobalt(II) complex with tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine tetrasodium salt is confirmed by the rate constant for the oxidation of sodium N,N-diethyldithiocarbamate, which is 12.31 l/mol*sec.

Claims (2)

Tetra-4-(3'-carboxyphenylsulfanyl)tetra-5-nitrophthalocyanine cobalt(II) tetrasodium salt, which has the properties of a homogeneous catalyst for the oxidation of sodium diethyldithiocarbamate of the formula: