Microwave-optical double resonance spectroscopy. Progress report, February 1, 1976--January 31, 1977

Technical Report · Mon Nov 01 04:00:00 EST 1976

DOI:https://doi.org/10.2172/7230627· OSTI ID:7230627

Pratt, D. W.

Zero-field and high-field optical detection of magnetic resonance (ODMR), electron paramagnetic resonance (EPR), and optical spectroscopy experiments have been performed on several systems in order to further basic knowledge of the structure, reactions, and response to radiation of atoms, molecules, and ions in their ground and/or excited electronic states. Particularly noteworthy results for the present contract year include the determination of the complete magnetic and optical properties of the lowest triplet states of 1-chloro, 1-bromo, and 1-iodonaphthalene, the development of a microscopic model for the intramolecular heavy-atom effect in the /sup 3/(..pi..,..pi..*) states of aromatic molecules, a detailed analysis of the angular dependence of the hyperfine and quadrupole structure in triplet 1-bromonaphthalene, observation of proton hyperfine structure in the hf ODMR spectra of short-lived triplet states, a definitive paper on the relative importance of spin delocalization and second-order spin-orbit coupling effects in /sup 3/(n,..pi..*) benzophenone (a phototype photochemical system), a detailed analysis of the level-anticrossing spectra of several triplet state benzophenones which exhibit hyperfine structure in the cross-relaxation region (thus permitting the determination of key magnetic parameters in the complete absence of perturbing microwave or radiofrequency fields), optical detection of ground-state NQR transitions in host crystal molecules, the observation of strong radiofrequency transitions near avoided crossing points in Zeeman energy level diagrams of photoexcited triplet states, the construction of zero-field ODMR, ODENDOR, and hf ODENDOR spectrometers, measurements of the activation parameters for ring interconversions of several free radicals containing five- and six-membered rings, and experimental proof that the triplet state of trimethylenemethane (a key reactive intermediate in organic chemistry) is the ground state.

• Research Organization: Pittsburgh Univ., PA (USA). Dept. of Chemistry
• OSTI ID: 7230627
• Report Number(s): COO-3435-27
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEAR CHEMISTRY
400301 -- Organic Chemistry-- Chemical & Physicochemical Properties-- (-1987)
400600* -- Radiation Chemistry
AROMATICS
BROMINATED AROMATIC HYDROCARBONS
CHEMISTRY
CHLORINATED AROMATIC HYDROCARBONS
CONDENSED AROMATICS
ELECTROMAGNETIC RADIATION
ELECTRON SPIN RESONANCE
ENERGY LEVELS
ENERGY-LEVEL TRANSITIONS
EXCITED STATES
HALOGENATED AROMATIC HYDROCARBONS
IODINATED AROMATIC HYDROCARBONS
IONIZING RADIATIONS
MAGNETIC PROPERTIES
MAGNETIC RESONANCE
OPTICAL PROPERTIES
ORGANIC BROMINE COMPOUNDS
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC IODINE COMPOUNDS
PHYSICAL PROPERTIES
RADIATION CHEMISTRY
RADIATIONS
RADICALS
RESEARCH PROGRAMS
RESONANCE
X RADIATION