Sensitization and quenching in the conversion of light energy into chemical energy. Progress report, February 1, 1979-January 31, 1980. [Benzylic chlorides]

Technical Report · Sat Sep 01 04:00:00 EDT 1979

OSTI ID:5911724

Cristol, S J

Data have been accumulated on the rates of excitation transfer from acetone or acetophenone sensitizers to several benzylic chlorides in acetonitrile-t-butyl alcohol or acetone-t-butyl alcohol and on the lifetimes of the excited triplet intermediates leading to solvolysis products (arylmethyl t-butyl ethers and arylmethanols). Lifetimes were found to be in the 0-2 nsec range. In direct irradiation, in t-butyl alcohol or acetonitrile-t-butyl alcohol, t-butyl ethers are formed from intermediates which are either singlets or are triplets of short lifetimes (0-2 nsec). Long-lived triplets, which do not lead to t-butyl ethers or to other products, but which decay to starting materials, and which arise by intersystem crossing from excited singlet states, were discovered by their ability to isomerize cis-piperylene (Hammond-Lamola quenching). These hidden triplets were shown to be produced as well by excitation transfer from benzophenone. They represent a large fraction of the energy wastage in this system. Work has begun on the preparation of materials for study of optically active benzylic chloride solvolyses, for study of optically active benzylic chloride solvolyses, for study of intramolecular (2 + 2) cycloadditions and for di-..pi..-methane studies, in our attempts to understand the mechanistic details of these important photochemical reactions.

• Research Organization: Colorado Univ., Boulder (USA)
• DOE Contract Number: AC02-79ER10366
• OSTI ID: 5911724
• Report Number(s): DOE/ER/10366-1; ON: DE85008112
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
ACETONE
ACETOPHENONE
ALCOHOLS
AROMATICS
BENZOPHENONE
BUTANOLS
CHEMICAL REACTIONS
CHEMISTRY
CHLORINATED AROMATIC HYDROCARBONS
DECOMPOSITION
ENERGY TRANSFER
ETHERS
HALOGENATED AROMATIC HYDROCARBONS
HYDROXY COMPOUNDS
KETONES
LIFETIME
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
PHOTOCHEMISTRY
REACTION INTERMEDIATES
RESEARCH PROGRAMS
SOLVOLYSIS