Selective Quenching of the Two Photoreaction Modes of Rh(NH3)5Br(2+).
Abstract
Rh(NH3)5Br(2+) is known to emit in aqueous solution, and quenching of this emission by hydroxide ion is reported. The quenching obeys Stern-Volmer kinetics with a bimolecular quenching rate constant, k(q), of 2.7 x 10 to the 10 power/M sec at 5 C. In acid solution the lifetime is 24.1 + or - 1.2 nsec at 5 C, with a temperature dependence of about 5 kcal/mole. The photochemistry is known to be primarily one of ammonia aquation, with a 10% component of bromide aquation. Under the same conditions as for emission lifetime quenching, there is parallel quenching of the ammonia aquation, with essentially the same k(q), but no quenching of the bromide aquation. It is therefore concluded that the emitting state is implicated in the former, but not in the latter. Possible revisions of excited state schemes to accommodate the new results are explored. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1980
- Accession Number
- ADA084340
Entities
People
- Arthur W. Adamson
- Marina T. Larson
- Robert C. Rumfeldt
Organizations
- University of Southern California