Kinetics of demetallation of manganese(II) porphyrins in aqueous solutions
Journal Article
·
· J. Phys. Chem.; (United States)
Radiolytic reduction of Mn/sup III/TPPS, Mn/sup III/TMPyP, and Mn/sup III/TPyP in acid solutions produces the manganese (II) porphyrins which then undergo demetallation. The rates of demetallation were monitored by kinetic spectrophotometry at various (H/sup +/). The results show that Mn/sup II/TPPS/ hydrolyzes to H/sub 4/TPPS/sup 2 +/ in a process whose rate is dependent on (H/sup +/) at 20-60 mM, with k approx. 1 x 10/sup 6/ M/sup -1/s/sup -1/, but dependent on (H/sup +/)/sup 2/ at (H/sup +/) < 10 mM, with K approx. 4 x 10/sup 7/ M/sup -2/s/sup -1/. The two pyridyl porphyrins demetallate much more slowly, with rate constants at 0.1-1.0 M H/sup +/ dependent on (H/sup +/)/sup 2/, with k approx. 5 x 10/sup 4/ M/sup -2/s/sup -1/.
- Research Organization:
- Univ. of Notre Dame, IN
- OSTI ID:
- 7202638
- Journal Information:
- J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 88:14; ISSN JPCHA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oxidation and reduction of manganese porphyrins in aqueous solutions by free radicals: a pulse radiolysis investigation
Reduction and demetalation of silver porphyrins in aqueous solutions
One- and two-electron reduction of aluminum and tin pyridylporphyrins. A kinetic spectrophotometric study. [Gamma Radiation]
Thesis/Dissertation
·
Tue Dec 31 23:00:00 EST 1985
·
OSTI ID:6303398
Reduction and demetalation of silver porphyrins in aqueous solutions
Journal Article
·
Thu Sep 17 00:00:00 EDT 1981
· J. Phys. Chem.; (United States)
·
OSTI ID:5948693
One- and two-electron reduction of aluminum and tin pyridylporphyrins. A kinetic spectrophotometric study. [Gamma Radiation]
Journal Article
·
Sat Dec 31 23:00:00 EST 1983
· J. Phys. Chem.; (United States)
·
OSTI ID:5889493
Related Subjects
08 HYDROGEN
080106 -- Hydrogen-- Production-- Biosynthesis & Photochemical Processes
14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400600 -- Radiation Chemistry
AQUEOUS SOLUTIONS
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
DISPERSIONS
EXPERIMENTAL DATA
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
KINETICS
MANGANESE COMPOUNDS
MIXTURES
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PH VALUE
PORPHYRINS
PULSE TECHNIQUES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
REACTION KINETICS
REDUCTION
SOLUTIONS
SPECTROPHOTOMETRY
TRANSITION ELEMENT COMPOUNDS
080106 -- Hydrogen-- Production-- Biosynthesis & Photochemical Processes
14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400600 -- Radiation Chemistry
AQUEOUS SOLUTIONS
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DECOMPOSITION
DISPERSIONS
EXPERIMENTAL DATA
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
KINETICS
MANGANESE COMPOUNDS
MIXTURES
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PH VALUE
PORPHYRINS
PULSE TECHNIQUES
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIOLYSIS
REACTION KINETICS
REDUCTION
SOLUTIONS
SPECTROPHOTOMETRY
TRANSITION ELEMENT COMPOUNDS