Time-resolved determinations of deuterium isotope effects on O/sub 2/(/sup 1/. delta. /sub g/) lifetimes in solution

Journal Article · Wed Nov 04 04:00:00 EST 1981 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00412a045· OSTI ID:5735987

Peters, G; Rodgers, M A.J.

Results of experiments applying a time-resolved substrate bleaching method to studies of determination of the natural lifetime (tau/sub ..delta../) of the lowest excited state of molecular oxygen, O/sub 2/(/sup 1/..delta../sub g/) as a function of the solvent and its isotopic condition are described. Fully protiated and fully deuterated species of benzene, acetonitrile, acetone, and chloroform were used as solvents, and diphenylisobenzofuran (DPBF) or rubene (R) were used as monitoring substances (M) for directly monitoring the loss of optical absorbance of M owing to the elementary process O/sub 2/(/sup 1/..delta../sub g/) + M ..-->.. (k/sub m/) -M. Values of tau/sub ..delta..//sup D//tau/sub ..delta..//sup H/ obtained from these experiments do not resolve the discrepancy of previously reported values obtained by different workers. However, it is concluded that in solvents where large tau/sub ..delta../ values (approx. 1000 ..mu..s) are exhibited, direct luminescence measurements technique is to be preferred over indirect methods. Contrarily, for tau/sub ..delta../ values of less than approx. 200 ..mu..s, it is contended that use of the time-resolved substrate bleaching method following flash excitation gives very reliable results. (BLM)

• Research Organization: Univ. of Texas, Austin
• OSTI ID: 5735987
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 103:22; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400202* -- Isotope Effects
Isotope Exchange
& Isotope Separation
ACETONE
ACETONITRILE
AROMATICS
BENZENE
BENZOFURANS
CHEMICAL REACTIONS
CHLORINATED ALIPHATIC HYDROCARBONS
CHLOROFORM
DEUTERIUM
ELEMENTS
ENERGY LEVELS
EXCITED STATES
FURANS
HALOGENATED ALIPHATIC HYDROCARBONS
HETEROCYCLIC COMPOUNDS
HYDROCARBONS
HYDROGEN ISOTOPES
ISOTOPE EFFECTS
ISOTOPES
KETONES
LABELLED COMPOUNDS
LIGHT NUCLEI
NITRILES
NONMETALS
NUCLEI
ODD-ODD NUCLEI
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
OXIDATION
OXYGEN
SOLVENT PROPERTIES
STABLE ISOTOPES