Muzaffer Alkan

Recovery of boric acid from boronic wastes by leaching with water, carbon dioxide- or sulfur dioxide-saturated water and leaching kinetics

Abstract B 2 O 3 was recovered from waste samples such as borogypsum, reactor waste, boronic sludges, waste mud and concentrator waste by leaching processes using distilled water, sulfur dioxide- and carbon dioxide-saturated water. In the leaching processes, temperature, stirring time and solid-to-liquid ratio were taken as parameters. The amount of B 2 O 3 leached increased with increasing temperature and stirring time and it also increased with decreasing solid-to-liquid ratio, but the increase was less than that recorded for the leaching temperature and the stirring time. SO 2 saturated water is a more effective leaching solvent than CO 2 saturated water for boronic wastes. By the end of the experiments, more than 90% of B 2 O 3 recovery was found as boric acid. In the leaching of boric acid from boronic wastes in water saturated with sulfur dioxide, it was observed that the leaching rate increases with increasing temperature and leaching time. The overall average values of the kinetic parameters were: apparent activation energy ( E ) 33.2 kJ mol −1 , pre-exponential factor ( A ) 8.2×10 9 min −1 , reaction order ( n ) 0.97 and rate constant ( k ) 3.37×10 3 min −1 for the leaching processes of the boronic wastes.

A Study on 4-Acylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones

Five novel 3-alkyl-4-phenylacetylamino-4,5-dihydro-1H-1,2,4-triazol-5-ones (2) were synthesized by the reactions of 3-alkyl-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones (1) with phenylacetyl chloride and characterized by elemental analyses and IR, 1HNMR, 13C-NMR and UV spectral data. The newly synthesized compounds 2 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents such as isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide, and the half-neutralization potential values and the corresponding pKa values were determined for all cases. In addition, these new compounds and five recently reported 3-alkyl-4-(pmethoxybenzoylamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones (3) were screened for their antioxidant activities.

Synthesis and Non-Aqueous Medium Titrations of Some New 4-Benzylidenamino-4,5-dihydro-1H-1,2,4-triazol-5-one Derivatives

The synthesis of 3-alkyl(aryl)-4-(3-ethoxy-4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-ones 3 from the reactions of 3-alkyl(aryl)-4-amino-4,5-dihydro-1H-1,2,4-triazol-5-ones 2 with 3-ethoxy-4-hydroxybenzaldehyde is described. The acetylation and methylation reactions of the compounds 3 giving compounds of type 4 and 5, respectively, were investigated. The newly synthesized compounds were characterized using elemental analyses and IR, 1H-NMR, 13C-NMR and UV spectral data. In addition, to investigate the effects of solvents and molecular structure upon acidity, compounds 3 were titrated potentiometrically with tetrabutylammonium hydroxide in four non-aqueous solvents (isopropyl alcohol, tert-butyl alcohol, acetonitrile and N,N-dimethylformamide). The half-neutralization potential values and the corresponding pKa values were determined for all cases.

B3LYP ve HF Temel Setleri Kullanılarak Bazı 3-Alkil-4-(2-asetoksi-3-metoksibenzilidenamino)-4,5-dihidro-1H-1,2,4-triazol-5-on Bileşiklerinin Deneysel ve Teorik Özelliklerinin İncelenmesi / The Investigation of Experimental and Theoretical Properties of Some 3-Alkyl-4-(2-acetoxy-3-methoxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-one Using B3LYP and HF Basis Sets

Bu calismada, bes adet 3-alkil-4-(2-asetoksi-3-metoksibenzilidenamino)-4,5-dihidro-1 H -1,2,4-triazol-5-on bilesiginin teorik ozellikleri B3LYP/6-311G(d,p) ve HF/6-311G(d,p) temel setleri kullanilarak incelenmistir. Ilk olarak, her bir molekul B3LYP/6-311G(d,p) ve HF/6-311G(d,p) temel setleri kullanilarak optimize edilmistir. Gaussian G09W paket programi kullanilarak GIAO metoduna gore molekullerin 1 H-NMR ve 13 C-NMR isotropik kayma degerleri hesaplanmistir. IR verilerinin belirlenmesinde veda4f programi kullanilmistir. Incelenen her bir molekulun iki farkli temel set ile IR (infrared) titresim frekans degerleri gaz fazinda hesaplanmis ve uygun uyum faktorleri ile carpilmistir. Elde edilen bu degerlere gore molekullerin infrared spektrumlari cizilmistir. Bilesiklerin bag uzunluklari, mulliken yukleri, en yuksek dolu molekuler orbital enerjisi (HOMO) ve en dusuk bos molekuler orbital enerjisi (LUMO), dipol moment degerleri de hesaplanmistir. In this study, theoretical properties of five 3-alkyl-4-(2-aceoxy-3-methoxybenzylidenamino)-4,5- dihydro-1 H -1,2,4-triazol-5-ones were investigated using B3LYP and HF basis sets. Firstly, each molecule were optimized by using the B3LYP/6-311G(d,p) and HF/6-311G(d,p) basis sets. 1 H-NMR and 13 C-NMR isotropic shift values of molecules were calculated by the method of GIAO using the program package Gaussian G09W. The veda4f program was used in defining IR data. IR (infrared) vibrational frequencie values with two different basis set investigated of each molecule was calculated in gas phase and are multiplied by appropriate adjustment factors. Infrared spectra of molecules according to obtained these values are formed. Also, bond lengths, mulliken charges, the highest occupied molecular orbital (HOMO) energys and the lowest unoccupied molecular orbital (LUMO) energys, dipole moment values of these compounds were calculated.

Synthesis and acidic properties of new 1-phenylacetyl-3-ethyl-4-(4-hydroxybenzylidenamino)-4,5-dihydro-1H-1,2,4-triazol-5-one

It is known that 1,2,4-triazole and 4,5-dihydro-1H-1,2,4-triazol-5-one rings have weak acidic properties, so some 1,2,4-triazole and 4,5-dihydro-1H-1,2,4-triazol-5-one derivatives were titrated potentiometrically with tetrabutylammonium hydroxide in non-aqueous solvents, and the pKa values of the compounds were determined [1,2,3].[...]

Synthesis and acidic properties of novel 3-methyl-4-[(2-amino-1,3,4-thiadiazol-5-il)-thioacetylamino]-4,5-dihydro-1H-1,2,4-triazol-5-one

A number of studies involving the determination of pKa values of some 4,5-dihydro-1H-1,2,4-triazol-5-one derivatives in non-aqueous solvents has been revealed [1,2,3].[...]