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1

Assay of the thermally stable, insensitive, high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB)

Nandi A. K., Thirupathi N., Mandal A. K., Pandey P. K.

Central European Journal of Energetic Materials

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2014

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Vol. 11, no. 2

295--305

EN

An aqueous titration method is described to assay the insensitive, high explosive 1,3,5-triamino-2,4,6-trinitrobenzene (TATB). TATB is initially quantitatively converted to the weak acid 1,3,5-trihydroxy-2,4,6-trinitrobenzene (THTNB) by base catalysed hydrolysis. Subsequently THTNB is assayed by acidbase titration. TATB samples obtained from regular batch operations are assayed by this method, and the results are compared with those obtained by the total amino functional group estimation method using a modified Kjeldhal apparatus. The method is simple and has good accuracy and precision.

2

Kinetics and Mechanism of Base Hydrolysis of Some (Aminomonocarboxylato)(tetraethylenepentamine) Cobalt(III) Complexes in Aqueous Medium

Das S., Patnaik A. K.

Polish Journal of Chemistry

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2009

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Vol. 83, nr 3

455-466

EN

Base hydrolysis of some (aminomonocarboxylato)(tetraethylenepentamine)Cobalt(III) complexes were studied in aqueous medium. The pseudo-first order rate constant fitted the relationship. kobs = kOH[OH-]T at 0.005 [OH-] mol dm-3 0.10 at 293.15 K-313.15 K, (I = 0.1 mol dm-3), where kOH denotes the second order base hydrolysis rate constant. The alfa beta R isomer of the alfa-alaninato complex reacted approximately 8 times faster than its alfa beta S analogue at 298.15 K. Also the reactivity difference kOH(pyridine- 2-carboxy lato)/kOH(beta-alaninato) asymptotic to 3 for the (alfa beta S) isomer is indicative of the relative electron displacement property of the pyridine ring and the aliphatic chain attached to the bound carboxylate function which influences partly the Co-O bond strength. The Dcb mechanism is valid for all these substrates. The ionic strength dependence of kOH in the range 0.01 Less-than or equal to I, mol dm-3 Less-than or equal to 0.1 for glycinato and beta-alaninato complex also confirmed the relationship log kOH = log kOH 0 + S1[I1/2/(1 + I1/2) + CI], where C is an adjustible parameter S1 = 2bZAZB, with b = 0.509 at 298.15 K, ZA and ZB denote charges of the reactant species. The acid catalyzed aquation indicated that alfa beta R-[(tetren)CoO2C-(CH3)NH3]3+ aquates via spontaneous (ko) and acid catalyzed (kaq) path. However, these reactions are extremely slow (ko = (1.74š0.17)×10-5 s-1, kaq = (2.72 + 0.05)×10-5 dm3 mol-1 s-1 at 333.15 K and I = 1.0 mol dm-3). Key words: kinetics mechanism, base hydrolysis, stopped flow, (aminomono carboxylato)(tetraethylenepentamine)cobalt(III)

3

Effect of Partially Aqueous Solutions of Different pH's on the Hydrolisis Rate of Some Schiff Bases

El-Taher M., El-Haty M. T., Hussien T. M.

Polish Journal of Chemistry

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2001

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Vol. 75, nr 1

79-91

EN

The mechanism of the hydrolysis of a series of Schiff bases derived from p-phenylenediamine and various aromatic aldehydes has been examined in aqueous media containing 40 wt% methanol, in the presence of NaOH. The base hydrolysis reaction of these compounds is strictly second-order kinetics, first-order with respect to the Schiff base and also to hydroxide ion, and the hydroxide ion attack on the free base becomes the rate-determining step under these basic conditions. The work is extended to include a systematic kinetic study on the hydrolysis reaction of the Schiff bases under investigation, in partially aqueous solutions of different pH's, in media containing 40 wt% methanol. Arate profile diagram of pH versus hydrolysis rate constant for all of the Schiff bases shows that the rate is minimal at alkaline region (pH > 8.96), and too rapid at strongly acidic media (pH < 3.53).