Abstract
The reaction between imidazole (Him) and phthalocyaninatoiron(II) [Fe(pc)] in dimethyl sulphoxide (dmso) has been studied, at 20 °C, from both equilibrium and kinetic points of view. In the presence of excess of Him the adduct [Fe(pc) (Him)2] is formed via two consecutive pseudo-first-order processes. The observed rate constants have the general form: kobs. = k1f[Him] + k1r with k1f′ = (9.8 ± 0.2) × 103 dm3 mol-1 s-1 and k1f″ = 5.4 ± 0.15 dm3 mol-1 s-1, for the binding of the first and second Him molecules, respectively. Equilibrium experiments yield K1′ = (6.4 ± 2.6) × 105 dm3 mol-1 and K1″ = (7.4 ± 0.5) × 103 dm3 mol-1 for the stepwise formation of the [Fe(pc) (dmso) (Him)] and [Fe(pc) (Him)2] adducts, respectively. From the values of the second-order rate constants (k1f′ and k1f″) and of the equilibrium constants (K1′ and K1″), the dissociation rate constants have been estimated to be k1r′ = 1.5 × 10-2 s-1 and k1r″ = 7.3 × 10-4 s-1. The results are discussed in the light of related previous studies.
| Original language | English |
|---|---|
| Pages (from-to) | 105-108 |
| Number of pages | 4 |
| Journal | Journal of the Chemical Society, Dalton Transactions |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1990 |
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Equilibrium and kinetic study of imidazole binding to phthalocyaninatoiron(II) in dimethyl sulphoxide. / Ascenzi, Paolo; Brunori, Maurizio; Pennesi, Giovanna; Ercolani, Claudio; Monacelli, Fabrizio.
In: Journal of the Chemical Society, Dalton Transactions, No. 1, 1990, p. 105-108.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Equilibrium and kinetic study of imidazole binding to phthalocyaninatoiron(II) in dimethyl sulphoxide
AU - Ascenzi, Paolo
AU - Brunori, Maurizio
AU - Pennesi, Giovanna
AU - Ercolani, Claudio
AU - Monacelli, Fabrizio
PY - 1990
Y1 - 1990
N2 - The reaction between imidazole (Him) and phthalocyaninatoiron(II) [Fe(pc)] in dimethyl sulphoxide (dmso) has been studied, at 20 °C, from both equilibrium and kinetic points of view. In the presence of excess of Him the adduct [Fe(pc) (Him)2] is formed via two consecutive pseudo-first-order processes. The observed rate constants have the general form: kobs. = k1f[Him] + k1r with k1f′ = (9.8 ± 0.2) × 103 dm3 mol-1 s-1 and k1f″ = 5.4 ± 0.15 dm3 mol-1 s-1, for the binding of the first and second Him molecules, respectively. Equilibrium experiments yield K1′ = (6.4 ± 2.6) × 105 dm3 mol-1 and K1″ = (7.4 ± 0.5) × 103 dm3 mol-1 for the stepwise formation of the [Fe(pc) (dmso) (Him)] and [Fe(pc) (Him)2] adducts, respectively. From the values of the second-order rate constants (k1f′ and k1f″) and of the equilibrium constants (K1′ and K1″), the dissociation rate constants have been estimated to be k1r′ = 1.5 × 10-2 s-1 and k1r″ = 7.3 × 10-4 s-1. The results are discussed in the light of related previous studies.
AB - The reaction between imidazole (Him) and phthalocyaninatoiron(II) [Fe(pc)] in dimethyl sulphoxide (dmso) has been studied, at 20 °C, from both equilibrium and kinetic points of view. In the presence of excess of Him the adduct [Fe(pc) (Him)2] is formed via two consecutive pseudo-first-order processes. The observed rate constants have the general form: kobs. = k1f[Him] + k1r with k1f′ = (9.8 ± 0.2) × 103 dm3 mol-1 s-1 and k1f″ = 5.4 ± 0.15 dm3 mol-1 s-1, for the binding of the first and second Him molecules, respectively. Equilibrium experiments yield K1′ = (6.4 ± 2.6) × 105 dm3 mol-1 and K1″ = (7.4 ± 0.5) × 103 dm3 mol-1 for the stepwise formation of the [Fe(pc) (dmso) (Him)] and [Fe(pc) (Him)2] adducts, respectively. From the values of the second-order rate constants (k1f′ and k1f″) and of the equilibrium constants (K1′ and K1″), the dissociation rate constants have been estimated to be k1r′ = 1.5 × 10-2 s-1 and k1r″ = 7.3 × 10-4 s-1. The results are discussed in the light of related previous studies.
UR - http://www.scopus.com/inward/record.url?scp=37049073040&partnerID=8YFLogxK
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U2 - 10.1039/DT9900000105
DO - 10.1039/DT9900000105
M3 - Article
SP - 105
EP - 108
JO - Journal of the Chemical Society. Dalton Transactions
JF - Journal of the Chemical Society. Dalton Transactions
SN - 1472-7773
IS - 1
ER -