- Kinetic study of iridium(III) catalyzed oxidation of D-mannitol and erythritol by N-bromosuccinimide in acidic medium
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Kinetic investigations on iridium trichloride catalyzed oxidation of D-mannitol and erythritol by acidic solution of N-bromosuccinimide (NBS) in the presence of mercuric acetate as a scavenger for Br- have been carried out in the temperature range 30-45 °C. The reactions follow identical kinetics. The rate shows a first-order dependence on [NBS] in lower concentration range which tends to zero-order at its higher concentrations. A first-order dependence on [IrIII] is also observed. Negligible effect of [substrate], [Hg(OAc)2] and ionic strength have been observed. Addition of [H+], [Cl-] and succinimide shows a negative effect. Activation parameters have been computed and a suitable mechanism conforming to above results has been proposed.
- Srivastava, Sheila,Gupta, Vandana
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p. 1103 - 1106
(2008/02/04)
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- TREATMENT OF SUGAR SOLUTIONS
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A process for treating a solution containing sugar and α-oxoaldehydes, comprising the step of adding a catalyst which comprises an optionally substituted histidine amino acid, such that the α-oxoaldehydes are catalytically converted to aldonic acids.
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Page/Page column 12; 13; Sheets 5-8
(2008/06/13)
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- Chemical reactions induced by ultrasound and γ-rays in aqueous solutions of L-ascorbic acid
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The degradation of L-ascorbic acid in aqueous solutions by ultrasound and ionising radiation was more extensive in the presence than in the absence of air.The primary products were L-erythro-2,3-hexodiulosonic acid, cis- and trans-L-glycero-4-hexulos-2-enonic acid; the secondary products were 2-pentulosonic acid, 4-pentulos-2-enonic acid, tetronic acid, and glyceric acid; and the tertiary product was tetraric acid.The formation of products with less than six carbon atoms was especially effective during irradiation in the presence of air.A mechanism for the degradation of L-ascorbic acid by sonolysis and radiolysis is proposed.
- Portenlaenger, Guenther,Heusinger, Helmut
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p. 291 - 302
(2007/10/02)
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- KINETICS AND MECHANISM OF Ru(III) CATALYSED OXYDATION OF SOME POLYHYDRIC ALCOHOLS BY N-BROMOSUCCINIMIDE IN ACIDIC MEDIA
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Kinetics of oxydation of ethylene glycol, glycerol, erythritol and dulcitol by acidic solution of N-bromosuccinimide (NBS) in presence of ruthenium(III) chloride as a homogeneous catalyst and mercuric acetate as scavenger in the temperature range of 30-50 deg C have been reported.The reactions follow identical kinetics, being first order in each NBS, substrate and Ru(III).Zero effect of , and ionic strength has been observed.A negative effect of succinimide and acetic acid is observed while shows the positive effect on reaction velocity.Various activation parameters have been computed.The products of the reaction were identified as the corresponding acids.A suitable mechanism consistent with the experimental results has been proposed.
- Sharma, J. P.,Singh, R. N. P.,Singh, A. K.,Singh, Bharat
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p. 2739 - 2748
(2007/10/02)
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