MICROWAVE AND RADIOFREQUENCY SPECTROSCOPY. Technical Report No. 33, May 1, 1960-August 1, 1960

Technical Report · Tue Oct 31 04:00:00 EST 1961

OSTI ID:4055188

Gordy, W

Two separate technical reports are presented. From the first observation of electron spin resonance of irradiated proteins in 1955 it was clear that the electron vacancy, or electron spin density, caused by the irradiation must be able to migrate through the protein from the multiple sites where the ionizing particles, or quanta, strike to the few sites such as the cystine sulfur where the spin density is finally detected. These original observations were carried out at room temperature. In the present work it is shown that such migrations do not, in fact, occur signiicantly at the temperature of liquid nitrogen, 77 deg K. Thus the migration of electron holes in the valence shell of proteins requires an activation energy, assistance from the molecular motions of excited vibrational or tortional oxcillational states. Electron spin resonance absorption of an irradiated single crystal of N-acetylglycine was observed at room temperature at 9 kMc/see and 23 kMc/sec. From the analysis of the aniotropy in the spectroscopic splitting factor and in the nuclear hyperfine interaction constant, a chemical structure is deduced for the free radical. The C-H bond is in the NCC plane and approximately along the bisector of the NCC angle. The unpaired electron spin density is essentially in a pi -orbital, about 72 per cent of which is the p orbital of the CH carbon directed perpendicular to the NCL plane. (auth)

• Research Organization: Duke Univ., Durham, N.C. Microwave Lab.
• NSA Number: NSA-15-020555
• OSTI ID: 4055188
• Report Number(s): OOR-291.33
• Country of Publication: United States
• Language: English

Related Subjects

BIOLOGY AND MEDICINE
CYSTEINE
ELECTRONS
IRRADIATION
MICROWAVES
PARTICLES
PROTEINS
RESONANCE
SPECTROSCOPY
SPIN
SULFUR