SU1703651A1 - Octasulphophenyltetraazaporphin as a reagent for quantitative determination of m@@@ ions in aqueous solutions - Google Patents

Abstract

The invention relates to substituted porphins, in particular, octasulfophenyltetraa-zorforfin for the quantitative determination of magnesium ions in aqueous solutions. The goal is to create a new, more effective substance of the specified class. Synthesis is carried out by dissolving MD-octaphenyl-tetra-zaporphin in 100% sulfuric acid, followed by precipitating the mixture in acetone. Yield 42%, gross f la Ci6H34Ne S (0) 20H. The new reagent provides better sensitivity (r - Mg / l ion, versus 8-1gU 4 5 g - MD / l ion) due to the formation of a strongly colored complex. 2 tab. w y

Description

The invention relates to the synthesis of new organic compounds — macroheterocyclic, in particular, to a new compound of the tetraazaporphyrin series, which can be used as a reagent for the quantitative determination of MD2 ions in aqueous solutions, namely, octasulfophenyl tetrazaporfin of the following formula:

S03H SO, H

Closest to the invention is unsubstituted octaphenyl tetraazoporphine - H2TAP (C5Hb).

The disadvantage of this compound is the extremely low reaction rate with the MD ion, the lack of a quantitative yield of the reaction, the insolubility in water and, as a consequence, the impossibility of determining MD2 ions in an aqueous medium:

but

CJ

Os

ate

E-SOjH

SOjH SOjH

244 nitro-2 -Fog. Phenophenyl-azo-1,8-dihydroxy-3, G nlphthalindisulfonic acid is known.

The disadvantages of the untrusted compound are the introduction of various additives to create a pH of the medium in which the complex is formed between the reagent and the MD ion, and the stability of the resulting complex is low. The sensitivity of the method is insufficient (g-ion / l).

Closest to the invention is tetrabromometraazaporfin.

The disadvantage of this compound is its use as a solvent in complexation with pyridine, since tetrasbromotetrazaporfin is insoluble in water. This makes analysis difficult, since pyridine is toxic and not all MD2 + salts are soluble in pyridine.

The aim of the invention is to create a new reagent for the quantitative determination of ions in aqueous solutions by a spectrophotometric method, which is distinguished by high sensitivity - g-ion / l and ease of analysis.

The goal is achieved by the synthesis of octasulfophenyltetrazaporfina - Н2ТАП (СБН4 $ ОН) and formula:

S03HS03H

R

yNH

 N HNHo s UT X / - SOJH

S03H S03H

The proposed compound contains in each phenyl radical of the analogue one sulfo group. This difference makes it possible to obtain a solid colored complex with an Mg + ion in water with a yield of 99.9%, a certain pH of the medium is not required, the determination of Md ions is distinguished by greater sensitivity (3-10 g-ion / l)

EXAMPLE 1 0.1 g of MD-octaphenyltetra-ae-porphine is dissolved under stirring in 10 ml of 100% and kept at room temperature for 4 hours. The reaction mixture is poured in small portions into 500 ml of acetone, cooled and the precipitated the precipitate is filtered off. The precipitate is washed with acetone (sample with BeCl3). dissolved in bo5 0

50

five

0

five

de, the solution is filtered and then evaporated. Solid black substance is extracted in the apparatus of the Soxhlet pyridine, acetone. The yield is 0.07 (42%). The octasulfophenyltetraazaporphine obtained is subjected to elemental analysis:

Found,%: C 49.29; H 2.50; N 6.87; S 16.02.

S1bNz4M8 (50zN) a

Calculated,%: C 49.14; H 2.71; N7, 17; 516.41.

The proposed compound is analyzed by thin layer chromatography on a Silufol plate (eluent is pyridine — 25% solution of NHS in a 1: 2 ratio). One spot is formed - RI 0.73.

The main characteristics of the ESP H2TAP (SbN450zN) in water are given in Table 1.

In the IR spectrum of the proposed compound, intense bands are present at 1200–1000 characteristic of sulfo groups (IR spectrum in KBr tablets).

PRI mme R 2. Definition of ions.

2 ml of an aqueous solution of H2TAP (SbN550zN) and with a concentration of mol / l are mixed with 2 ml of a solution of magnesium salt in water. The reaction mixture was incubated for 2 hours at 50 ° C. The optical density of the solution is then measured at a wavelength of A 635 nm corresponding to a maximum in the ESP of the complex formed. The molar coefficient of redemption (ТА) MDTAP (SbN450zN) 8 (e - 45500), its concentration is calculated (g-mol / l) according to the formula:

WITH

A 0.1 LG 45500-1

2.19-10

40

where A is the optical density of the solution at a wavelength of 635 nm;

Ј — molar extinction coefficient at Я 635 nm;

 cuvette thickness, see

The main characteristics of the ESP MDTAP (SbN450zN) and in water are given in Table 2.

Quantitative determination of MD2 + ions in water is given in Table. 3

When using the proposed compound for the quantitative determination of Md ions by a spectrophotometric method, a high sensitivity is achieved and the experiment is made simpler.

Claims (1)

Claims of the invention: Octasesulfophenyltetraazaporfin of the formula SO, H H03S-C S03H as a reagent for the quantitative determination of Md ions in aqueous solutions. Table 1 table 2 Table 3