Study on the Complex Formation and the Ion-Association of Anionic Chelate of Molybdenum(VI) with Bidentate Ligand and the Cation of 2,3,5-Triphenyl-2?-tetrazolium Chloride.

The complex formation between the anionic chelate of molybdenum(VI) with the bidentate ligand of 3,5-dinitrocatechol (3,5-DNC) and its ion-association with the cation of 2,3,5-triphenyl-2?-tetrazolium chloride (TTC) in the liquid-liquid extraction system Mo(VI)?3,5-DNC?TTC?H2O?CHCl3 were studied by spectrophotometry. The validity of Beer's law was checked and some analytical characteristics of the system were calculated under the optimum conditions for the chelate formation and extraction. The effect of various co-existing ions and reagents on the process of chelate formation and ion-association was investigated. The molar ratio of the components in the ion-associated complex Mo(VI)-3,5-DNC-TTC was determined by independent methods. The association process in aqueous phase and the extraction equilibria were investigated and quantitatively characterized by the following equilibrium constants: association constant, distribution constant, extraction constant and recovery factor. Based on this, a reaction scheme, a general formula and a structural formula of the complex were suggested.

Ion-Associated Complex of the Anionic Chelate of Germanium(IV) with Nitro Derivative of the Catechol and the Cation of Monotetrazolium Salt.

The formation of an ion-associated complex between of the anionic chelate of germanium(IV) with 4-nitrocatechol (4- NC) and the cation of 3-(2-naphtyl)-2,5-diphenyl-2H-tetrazolium chloride (TV) was investigated by spectrophotometry. The optimum conditions for the chelate formation and the extraction of the complex in the liquid-liquid extraction system Ge(IV)α4-NCαTVαH2OαCHCl3 were established. The validity of Beer's law was checked and some analytical characteristics were calculated. The association process in the aqueous phase and the extraction equilibria were studied and quantitatively characterized by the following key constants: association constant, distribution constant, extraction constant and recovery factor. The molar ratios of the components in the ion-associated complex were determined by independent methods. Based on this, a reaction scheme, a general formula and a structure of the ion-associated complex were suggested.

Study on the Chelate Formation and the Ion-association of Anionic Chelate of Molybdenum(VI) with 3,5-Dinitrocatechol and Monotetrazolium Cation.

The equilibria of the chelate formation and ion-association in the liquid-liquid extraction system Mo(VI)‒3,5-DNC‒INT‒H2O‒CHCl3 were studied by spectrophotometry. The optimum conditions for the chelate formation and extraction of the ion-associated complex formed between the anionic chelate of Mo(VI)‒3,5-dinitrocatechol (3,5-DNC) and the cation of 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride (INT) were established. The validity of Beer's law was checked and some analytical characteristics were calculated. The effect of various co-existing ions and reagents on the process of complex formation was investigated. The molar ratio of the components in the ternary ion-associated complex Mo(VI)-3,5-DNC-INT was determined by independent methods. The association process in aqueous phase and the extraction equilibria were investigated and quantitatively characterized. The following key constants of the processes were calculated: association constant, distribution constant, extraction constant and recovery factor. Based on this, a reaction scheme, a general formula and a structure of the complex were suggested.

Study on the Equilibria of the Complex Formation of the Ion-pair of Germanium(IV) with 4-Nitrocatechol and 1,4-Diphenyl-3-(phenylamino)-1H-1,2,4-triazole.

The complex formation of the ion-pair formed between the anionic chelate of Ge(IV)-4-nitrocatechol (4-NC) and the cation of 1,4-diphenyl-3-(phenylamino)-1H-1,2,4-triazole (Nitron, Nt) in the liquid-liquid extraction system Ge(IV)-4-NC-Nt-H2O-CHCl3 was studied by spectrophotometry. The optimum extraction-spectrophotometric conditions for the complex formation were established. The validity of Beer's law was checked and some analytical characteristics of the system were calculated. The effect of co-existing ions and reagents on the process of complex formation was investigated. The association process in aqueous phase and the extraction equilibria were studied and quantitatively characterized. The following key constants of the processes were calculated: association constant, distribution constant, extraction constant and recovery factor. The molar ratio of the reagents was determined by independent methods. A reaction scheme and a general formula of the complex were suggested.

Study on the Complex Equilibria of Molybdenum(VI) with 3,5-Dinitrocatechol and Ditetrazolium Salt.

The complex formed between an anionic chelate of Mo(VI)-3,5-dinitrocatechol (3,5-DNC) with the cation of 3,3'-(3,3'-dimethoxy-4,4'-biphenylene)bis(2,5-diphenyl-2H-tetrazolium chloride) (Blue Tetrazolium Chloride, BTC) in the liquid-liquid extraction system Mo(VI)-3,5-DNC-BTC-H2O-CHCl3 was studied. The optimum conditions for the complex formation and extraction of the ion-associated complex were established by spectrophotometry. The molar ratio of the reagents was determined by independent methods. The validity of Beer's law was checked and some analytical characteristics were calculated. The association process in aqueous phase and the extraction equilibria were investigated and quantitatively characterized. The following key constants of the processes were calculated: association constant, distribution constant, extraction constant and recovery factor. Based on this, a reaction scheme, a general formula and a structure of the complex were suggested.

Complex Formation in a Liquid-Liquid Extraction System Containing Co(II), 4-(2-Thiazolylazo)resorcinol and Monotetrazolium Salt.

The ion-associated complex formed between anionic chelate of Co(II)-4-(2-Thiazolylazo)resorcinol (TAR) with the monotetrazolium cation of 2-(4-Iodophenyl)-3-(4-nitrophenyl)-5-phenyl-2H-tetrazolium chloride (INT) in the liquid-liquid extraction system Co(II)-TAR-INT-H(2)O-CHCl(3) was studied by the spectrophotometric method. The optimum extraction conditions of Co(II) were found. The extraction equilibria were studied. The equilibrium constants, the recovery factor and some analytical characteristics were calculated. The validity of Beer's law was checked. The molar ratio of the components in the ternary ion-associated complex Co(II)-TAR-INT was determined. The general formula of the complex was suggested. The effect of various foreign ions and reagents on the process of complex formation in the liquid-liquid extraction system was studied.

Ternary ion-association complexes of cobalt with 4-(2-pyridylazo)resorcinol and tetrazolium salts.

The formation of ternary ion-association complexes of Co(II) with 4-(2-pyridylazo)resorcinol (PAR) and tetrazolium salts (TS) - (3-(4,5-dimethylThiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) and 3-(2-naphtyl)-2,5-diphenyl-2H-tetrazolium chloride (TV) - were investigated with the aid of the extraction-spectrophotometric method. The optimum conditions for the extraction of Co(II) were found. On the basis of the experimental data and their mathematical treatment the association process in aqueous phase and extraction process was investigated quantitatively. The molar ratios of the components in the associates were determined. The results show that the extracted species could be represented with the general formula (TS)[CoH(PAR)(2)]. The following key constants were calculated: association constant, distribution constant, extraction constant and recovery factor. The validity of Beer's law was checked and some analytical characteristics were calculated.

Ion-association complexes of gallium(III)-4-(2-pyridylazo)-resorcinol anionic chelates and dicationic tetrazolium reagents.

The formation and liquid-liquid extraction of ion-association complexes between gallium(III)-4-(2-pyridylazo)resorcinol (PAR) anionic chelates and cations of four ditetrazolium chlorides (DT2+) were studied: Neotetrazolium chloride (NTC), Blue Tetrazolium chloride (BTC), Nitro Blue Tetrazolium chloride (NBT) and Tetranitro Blue Tetrazolium chloride (TNBT). The optimum extraction-spectrophotometric conditions, composition of the extracted species {1:2:1 and/or 1:2:2 (Ga:PAR:DT)}, some equilibrium constants {constants of association (beta), constants of distribution (KD and constants of extraction (Kex)} and analytical characteristics {molar absorptivity (epsilon), Sandell's sensitivity, intervals of adherence to Beer's law, etc.} were found. Relationships involving the number of nitro groups in DT2+ (Nnitro; DT2+ = BT2+, NBT2+ and TNBT2+) or molecular mass of DT2+ (MM; DT2+ = NT2+ and BT2+) were discussed: Log beta =f(Nnitro), Log KD =f(Nnitro), Log Kepsilon=f(Nnitro), Log epsilon =f(Nnitro) and Log beta = f(Log MM).