Aqueous solution photophysics and photochemistry of dihalo- and aquahalobis(ethylenediamine)rhodium(III). Effect of nonreacting amine ligands on excited-state halide dissociation and excited-state rearrangement
Ligand field excitation of cis- and trans-(Rh(en)2X2) (X = Cl, Br) in acidic aqueous solution leads to halide photoaquation producing (Rh(en)2(H2O)X)S . Room-temperature phosphorescence lifetimes of the four dihalo complexes in aqueous solution were measured by using a mode-locked laser and time-correlated single-photon detection and found to be about 2 ns in each case. Excited-state halide dissociation and nonradiative deactivation rate constants were evaluated from a combination of the lifetimes and the photoaquation quantum yields. The halide dissociation rate constants range from 1.9 x 10Y (cis-dichloro) to 2.1 x 10X s (trans-dibromo) and are in all cases smaller (by a factor of 1.6-15) than the rate constants previously determined for the tetraammine and bis(1,3-propanediamine) analogues. Also described are the syntheses of the dithionate salts of trans- and cis-(Rh(en)2(H2O)X)S , and quantum yields for the cis/trans interconversion of each isomeric pair in aqueous solution at 25C are given.
- Research Organization:
- Royal Veterinary and Agricultural Univ., Frederiksberg C, Denmark
- OSTI ID:
- 6163622
- Journal Information:
- Inorg. Chem.; (United States), Vol. 26:11
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AMINES
EXCITED STATES
PHOTOCHEMICAL REACTIONS
BROMINE COMPOUNDS
CHLORINE COMPOUNDS
RHODIUM COMPLEXES
AQUEOUS SOLUTIONS
CHEMICAL REACTION KINETICS
EXPERIMENTAL DATA
LIFETIME
LIGANDS
PHOTOCHEMISTRY
QUANTUM EFFICIENCY
CHEMICAL REACTIONS
CHEMISTRY
COMPLEXES
DATA
DISPERSIONS
EFFICIENCY
ENERGY LEVELS
HALOGEN COMPOUNDS
INFORMATION
KINETICS
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
REACTION KINETICS
SOLUTIONS
TRANSITION ELEMENT COMPLEXES
400500* - Photochemistry