caa a22 4500 465775225 CHVBK 20180323111939.0 cr unu---uuuuu 170327e19900201xx s 000 0 eng 10.1007/BF01032233 doi (NATIONALLICENCE)springer-10.1007/BF01032233 An independent kinetic and mechanistic study of the secondary reactions in the substitution of [FeL(OH)](n−2)− (L= triethylenetetraaminehexaacetic acid) by cyanide ions [Elektronische Daten] [Surendra Prasad, Prem Nigam, Radhey Naik] Summary: The kinetics of reaction between [Fe(CN)5OH]3− and CN− have been investigated spectrophotometrically at pH=11.00, I=0.25 M(NaClO4) and temp.=25.0°C by disappearance of the absorption peak at 395 nm. The rate data for this reaction followed first order kinetics in both [Fe(CN)5OH3−] and [CN−]. The second order rate constant (kf) was found to be (3.44±0.08)×10−3 M−1 s−1. The pH dependence of the reaction was also investigated in the range 9-12. The activation parameters were found to be ΔH†=36.4kJ mol−1 and ΔS†=−168JK−1 mol−1. The reaction between [Fe(CN)6]3− and TTHA6− (TTHA=triethylenetetraaminehexaacetic acid) has also been followed spectrophotometrically at 420 nm, pH=11.00, I=0.1M (NaClO4) and temp.=25.0°C. This reaction also followed first order kinetics in both [Fe(CN) 6 3− ] and [TTHA6−]. The second order rate constant (kf) was found to be (3.74±0.21)×10−2 M−1 s−1. The rate of reaction was found to increase with pH in the range 9-11.5. The different reactive species of TTHA (L) are H2L4− HL5− and L6−. The rate constants for these species have been calculated and the pH profile is explained. The values of the activation parameters were found to be ΔH†= 30.9 kJmol−1 and ΔS†=−167JK−1 mol−1. Electron transfer from [Fe(CN)6]3− to the substrate followed by decomposition of the latter is proposed. The oxidation products of TTHA have been investigated by g.l.c. Chapman and Hall Ltd., 1990 Prasad Surendra Department of Chemistry, Indian Institute of Technology, 208016, Kanpur, India aut Nigam Prem Department of Chemistry, Indian Institute of Technology, 208016, Kanpur, India aut Naik Radhey Department of Chemistry, Manipur University, Canchipur, Imphal, (India) aut Transition Metal Chemistry Kluwer Academic Publishers 15/1(1990-02-01), 58-62 0340-4285 15:1<58 1990 15 11243 https://doi.org/10.1007/BF01032233 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01032233 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Prasad Surendra Department of Chemistry, Indian Institute of Technology, 208016, Kanpur, India aut NATIONALLICENCE 700 1- Nigam Prem Department of Chemistry, Indian Institute of Technology, 208016, Kanpur, India aut NATIONALLICENCE 700 1- Naik Radhey Department of Chemistry, Manipur University, Canchipur, Imphal, (India) aut NATIONALLICENCE 773 0- Transition Metal Chemistry Kluwer Academic Publishers 15/1(1990-02-01), 58-62 0340-4285 15:1<58 1990 15 11243 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer