Kinetic isotope effect for the coordination reaction of porphyrins with zinc and cadmium salts in binary pyridine-H/sub 2/O(D/sub 2/O) and DMF-H/sub 2/O(D/sub 2/O) solvents
Kinetic isotope effects (k/sub H//k/sub D/ = 1.2-1.9) have been measured for complex formation reactions of tetraphenylporphyrin and tetra(p-methoxyphenyl)porphyrin with cadmium and zinc acetate, as well as with zinc nitrate, in binary pyridine-H/sub 2/O(D/sub 2/O) and DMF-H/sub 2/O(D/sub 2/) solvent systems. For the substitution reaction of cadmium in cadmium tetraphenylporphyrin by zinc, k/sub H//k/sub D/ = 1. The kinetic isotope effects observed for the formation reactions of metalloporphyrins are associated with NH-ND substitution in porphyrin molecules. The low value of kinetic isotope effect can be explained in terms of a small bending distortion of the NH bonds in porphyrins and by the nonlinear configuration of the N...H...Solv fragments (porphyrin nitrogen atom...departing hydrogen atom...solvating solvent molecule) in the transition state.
- Research Organization:
- Institute of Nonaqueous Solution Chemistry, Ivanova (USSR)
- OSTI ID:
- 6093042
- Journal Information:
- Kinet. Catal. (Engl. Transl.); (United States), Vol. 28:6; Other Information: Translated from Kinet. Catal.; 28, No. 6, 1301-1306 (Nov-Dec 1987)
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ACETATES
COMPLEXOMETRY
CADMIUM COMPOUNDS
DEUTERIUM
ISOTOPE EFFECTS
PORPHYRINS
ZINC COMPOUNDS
CADMIUM COMPLEXES
CHEMICAL BONDS
CHEMICAL REACTION KINETICS
HEAVY WATER
HYDROGEN TRANSFER
ISOTOPIC EXCHANGE
ORGANIC SOLVENTS
PYRIDINE
ZINC COMPLEXES
ZINC NITRATES
AZINES
CARBOXYLIC ACID SALTS
CARBOXYLIC ACIDS
COMPLEXES
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
ISOTOPES
KINETICS
LIGHT NUCLEI
NITRATES
NITROGEN COMPOUNDS
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PYRIDINES
REACTION KINETICS
SOLVENTS
STABLE ISOTOPES
WATER
400202* - Isotope Effects
Isotope Exchange
& Isotope Separation