caa a22 4500 378871110 CHVBK 20180305123409.0 cr unu---uuuuu 161128e20030101xx s 000 0 eng 10.1515/irm-2003-0101 doi (NATIONALLICENCE)gruyter-10.1515/irm-2003-0101 Kinetics and Mechanism of the Reaction of Ninhydrin with Chromium(III)-tryptophan Complex in Absence and Presence of Surfactants [Elektronische Daten] [Kabir-Ud-Din,, Mohammad Akram, Zaheer Khan] The kinetics of the title reaction have been investigated in both aqueous and micellar cetyltrimethylammonium bromide(CTAB) solutions. Rate data indicate that the reaction follows the template mechanism in both the media. The observed rate constant is affected by [CTAB] changes and the maximum rate enhancement is ca. 4 -fold. The following parameters have been calculated at pH 5.0: for aqueous, kobs = 5.6 χ 10-5 s-1, ΔH* = 61 k J mol-1, ΔS* = -122 J K-1mol-1 ; for CTAB , kΨ = 24.7 χ 10-5 s-1 , ΔH* = 35 k J mol-1, ΔS* = -200 J K-1 mol-1, which reveal CTAB behaving as a catalyst. To explain the dependence of the reaction rate on [CTAB], pseudo-phase model proposed by Menger and Portnoy and modified by Bunton and Rodenas was used. The catalytic role of CTAB can be related to the extent of incorporation or association of the chromium(III)-tryptophan and ninhydrin into the micelles. Various factors which affect km, Ks KN and are discussed taking into account the micellar surface solvent properties. © 2014 by Walter de Gruyter Berlin/Boston Chromium(III)-tryptophan nationallicence Ninhydrin nationallicence Kinetics nationallicence Mechanism nationallicence Micelles nationallicence CTAB nationallicence Kabir-Ud-Din, aut Akram Mohammad aut Khan Zaheer aut BioInorganic Reaction Mechanisms De Gruyter 5/1(2003-01-01), 1-12 2191-2483 5:1<1 2003 5 irm https://doi.org/10.1515/irm-2003-0101 text/html Onlinezugriff via DOI 1 research article jats NATIONALLICENCE 856 40 https://doi.org/10.1515/irm-2003-0101 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Kabir-Ud-Din aut NATIONALLICENCE 700 1- Akram Mohammad aut NATIONALLICENCE 700 1- Khan Zaheer aut NATIONALLICENCE 773 0- BioInorganic Reaction Mechanisms De Gruyter 5/1(2003-01-01), 1-12 2191-2483 5:1<1 2003 5 irm CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-gruyter