OH radical in water studied by Quantum beats on positron annihilation -the effect of water liquid structures-

Abstract

OH radical in water studied by Quantum beats on positron annihilation -the effect of water liquid structuresTo cite this article: Jeong-Jae Lee et al 2010 J. Phys.: Conf. Ser Abstract. Singlet radical pairs of ortho-positronium and hydroxyl (OH) radical were generated in positron radiolysis in water. Quantum beats on the energy distribution of positron annihilation γ-rays caused by the reaction of electron-spin-correlated pairs of orthopositronium and OH radical were newly measured at 32°C by using positron annihilation agemomentum correlation (AMOC) measurement. The quantum beats can provide information of hyperfine coupling constants of the OH radical in water liquid structures, and hence can provide the information of change of the water liquid structures. The quantum beats appeared at 32°C could not be explained easily. The reason was continuous and slow change of water liquid structures at 32°C. The water liquid structures probably can be understood by using the positron annihilation quantum beat measurements.

Spin effects govern DNA/RNA nucleotide polymerization

“…The diffusion is accompanied by multistep structural rearrangements of the OH radical in the 'water tube' (2.65 Å in length) of 11 (the first and second shells) water molecules. These rearrangements are the result of hydrogen bond forming/ breaking between the OH and water molecules; the O-H bond length in the radical varies in the intervalr max (O-H) = 1.12 Å, r min (O-H) = 0.96 Å-that coincides with the previously observed data [41]. When the OH is as close to the HO-C 2' as 1.54 Å, the H-O bond in the HO-C 2' displays a progressive lengthening.…”

“…The reason for keeping the spins parallel on the both radicals is in the highly large HF constant , produced by the AMP -radical [25]. According to our computations (CPMD, section II), the value of  reaches 0.078 T. The strong magnetic coupling between the 31 P atom and the unpaired electron on the AMP -aligns the spin of OH (the  in the OH-(5H 2 O) complex at 310 K is 0.036 T-a result of the OH magnetic field enhancement by surrounding water molecules [41]) in the identical direction to that on the AMP -, and the environment cannot destroy the effect in the distance range 4.75 -1.50 Å between the AMP -and OH. The finding is crucial for the radical polymerization to occur, see below.…”

Ortho-Positronium Reactions in Water Studied by Positron Annihilation Age-Momentum Correlation

“…Lee et al indicated that the shape of S(t) changed with the elapsed time during measurements. [16] Even for 11°C, the shape changed during measurements. Now, the reason is not clear but change of the water liquid structures probably affected the shape of S(t).…”