Reduction and demetalation of silver porphyrins in aqueous solutions

Journal Article · Thu Sep 17 04:00:00 EDT 1981 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j150619a026· OSTI ID:5948693

Kumar, A; Neta, P

The reduction of silver porphyrins and the demetalation of the reduced species in aqueous solutions were studied by steady-state and pulse radiolysis. Ag/sup III/TPPS is reduced to Ag/sup II/TPPS by e/sub eq//sup -/ with k = 1.0 x 10/sup 10/ M/sup -1/ s/sup -1/ Ag/sup II/TPPS is reduced by e/sub eq//sup -/ (k = 1.6 x 10/sup 10/) and by (CH/sub 3/)/sub 2/COH (k = 6 x 10/sup 8/ M/sup -1/ s/sup -1/) to Ag/sup I/TPPS. Ag/sup I/TPPS reacts with water (k = 5 x 10/sup 4/ s/sup -1/) to give HAg/sup I/TPPS and the latter also reacts with water (k = 1.3 x 10/sup 3/ s/sup -1/) to yield Ag/sup +/ + H/sub 2/TPPS as final products. H/sub 2/TPPS is also reduced by e/sub eq//sup -/ rapidly, k = 1.5 x 10/sup 10/ M/sup -1/ s/sup -1/. The anion radical (H/sub 2/TPPS)/sup -/. transfers an electron to Ag/sup II/TPPS somewhat slowly, k less than or equal to 5 x 10/sup 6/ M/sup -1/ s/sup -1/, but the process occurs efficiently under ..gamma..-radiolysis conditions.

• Research Organization: Univ. of Notre Dame, IN
• OSTI ID: 5948693
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 85:19; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400201 -- Chemical & Physicochemical Properties
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400600* -- Radiation Chemistry
ABSORPTION SPECTRA
AQUEOUS SOLUTIONS
BEAMS
CARBOXYLIC ACIDS
CHEMICAL RADIATION EFFECTS
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DATA
DECOMPOSITION
DEMETALLIZATION
DISPERSIONS
ELECTROMAGNETIC RADIATION
ELECTRON BEAMS
EXPERIMENTAL DATA
FLUID FLOW
GAMMA RADIATION
HETEROCYCLIC ACIDS
HETEROCYCLIC COMPOUNDS
INFORMATION
IONIZING RADIATIONS
IRRADIATION
KINETICS
LEPTON BEAMS
MEDIUM TEMPERATURE
MIXTURES
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PARTICLE BEAMS
PORPHYRINS
PULSED IRRADIATION
RADIATION CHEMISTRY
RADIATION EFFECTS
RADIATIONS
RADIOLYSIS
REACTION KINETICS
REDUCTION
SEPARATION PROCESSES
SILVER COMPLEXES
SOLUTIONS
SPECTRA
STEADY FLOW
TRANSITION ELEMENT COMPLEXES