TY - JOUR
T1 - Formation kinetics of peroxovanadium(V) complexes in strongly acidic media as studied by a high-pressure stopped-flow technique
AU - Funahashi, Shigenobu
AU - Ishihara, Koji
AU - Inamo, Masahiko
AU - Tanaka, Motoharu
N1 - Funding Information:
S.F. gratefully acknowledges financial support by a giant from the Ktuiata Foundation for purcl,asing tantalum block. The present work was supported by a Grant-in-Aid for Scientific Research (No. 62470041) and a Grant-in-Aid for Special Project Research (No. 62124039) from the Ministry of Education, Science and Culture.
PY - 1989/3/1
Y1 - 1989/3/1
N2 - A high-pressure stopped-flow vessel was made of acid-proof tantalum block which enabled us to follow reactions of vanadium(V) ion with hydrogen peroxide in strongly acidic media. The rate for the formation of the monoperoxo complex (VO(O2)+) is expressed as d [VO(O2)+]/dt = (k1[H+]-1 + k2 + k3 [H+])[VO2+]- [H2O2] where k1 (s-1) (25 °C)=60.2 [ΔH≠ (kJ mol-1 = 21.1 ± 2.6, ΔS≠ (J mol-1 K-1) = - 140 ± 9, ΔV≠ (cm3 mol-1) = 9.9 ± 1.7], k2 (mo1-1 dm3 s-1) (25 °C) = 3.47 × 103 [ΔH≠ = 46.5 ± 1.3, ΔS≠ = -21 ±4, ΔV≠ = 2.8 ± 1.0] and k3 (mol-2 dm6 s-1) (25 °C) = 1.63 × 103 [ΔH≠ = 20.1 ± 4.7, Δ [tl]S≠ = -116 ± 16, ΔV≠ = 14.2 ± 3.2]. The rates of formation and dissociation of the diperoxo complex are described as d [VO(O2)2-]/dt = kf [VO(O2)+] [H2O2] and - d [VO(O2)2-]/dt = kd [VO(O2)2-] [H+]2, respectively, where kf (mol-1 dm3 s-1) (25 °C) = 3.49 × 103 [ΔH≠ (kJ mol-1) = 40.2 ± 0.8, ΔS≠ (J mol-1 K-1) = -42±3, ΔV≠ (cm3 mol-1) =0.0±0.2]. and kd (mol-2 dm6 s-1) (25 °C) = 3.79 × 103 [ΔH≠ = 45.7 ± 1.7, ΔS≠ = -23 ∓ 6]. Positive volumes of activation for the monoperoxo complex formation have been attributed to an expanded transition state with the distorted pentagonal-bipyramidal structure.
AB - A high-pressure stopped-flow vessel was made of acid-proof tantalum block which enabled us to follow reactions of vanadium(V) ion with hydrogen peroxide in strongly acidic media. The rate for the formation of the monoperoxo complex (VO(O2)+) is expressed as d [VO(O2)+]/dt = (k1[H+]-1 + k2 + k3 [H+])[VO2+]- [H2O2] where k1 (s-1) (25 °C)=60.2 [ΔH≠ (kJ mol-1 = 21.1 ± 2.6, ΔS≠ (J mol-1 K-1) = - 140 ± 9, ΔV≠ (cm3 mol-1) = 9.9 ± 1.7], k2 (mo1-1 dm3 s-1) (25 °C) = 3.47 × 103 [ΔH≠ = 46.5 ± 1.3, ΔS≠ = -21 ±4, ΔV≠ = 2.8 ± 1.0] and k3 (mol-2 dm6 s-1) (25 °C) = 1.63 × 103 [ΔH≠ = 20.1 ± 4.7, Δ [tl]S≠ = -116 ± 16, ΔV≠ = 14.2 ± 3.2]. The rates of formation and dissociation of the diperoxo complex are described as d [VO(O2)2-]/dt = kf [VO(O2)+] [H2O2] and - d [VO(O2)2-]/dt = kd [VO(O2)2-] [H+]2, respectively, where kf (mol-1 dm3 s-1) (25 °C) = 3.49 × 103 [ΔH≠ (kJ mol-1) = 40.2 ± 0.8, ΔS≠ (J mol-1 K-1) = -42±3, ΔV≠ (cm3 mol-1) =0.0±0.2]. and kd (mol-2 dm6 s-1) (25 °C) = 3.79 × 103 [ΔH≠ = 45.7 ± 1.7, ΔS≠ = -23 ∓ 6]. Positive volumes of activation for the monoperoxo complex formation have been attributed to an expanded transition state with the distorted pentagonal-bipyramidal structure.
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U2 - 10.1016/S0020-1693(00)83425-8
DO - 10.1016/S0020-1693(00)83425-8
M3 - Article
AN - SCOPUS:4243224178
SN - 0020-1693
VL - 157
SP - 65
EP - 71
JO - Inorganica Chimica Acta
JF - Inorganica Chimica Acta
IS - 1
ER -