Effect of mass on particle diffusion in liquids studied by electron spin exchange and chemical reaction of muonium with oxygen in aqueous solution

Abstract

Ph ys ika lisch -Ch em isch es Ins titu t de r Un i ve rsi ta t Zurich, Win te rth ure rs tra ss e 190, C Ha057 Z u rich, Switzerland

Isotope Dependence and Quantum Effects on Atomic Hydrogen Diffusion in Liquid Water

“…The rate constant ratios supersede those of a previous determination based on spin exchange of Mu with O 2 , which had to be separated from chemical reaction and therefore was less accurate. 37 ) A second isotope effect is present in comparison of the H atom diffusion in 90% D 2 O to its diffusion in 100% H 2 O. This is not unexpected given the ca.…”

Oxygen Detection in Biological Aqueous Solutions using Positive Muon for Cancer Research

“…The spin precession of the Mu took faster relaxation against the increase of O 2 concentration. These time spectra are fitted with function; The relaxation rate of Mu with O 2 concentration in pure water shows consistency with previous data (Roduner et al, 1995). Then the measurement was carried out in biological molecules.…”

“…Brown J. M. et al, (2004) mentioned that the concentration of oxygen in tumorous part in human body is heterogeneous (less than 5 mmHg). From muon spin measurements, the muon spin can probe oxygen in water (Jean et al, 1979;Nagamine and Nishiyama 1982;Roduner et al, 1995) between 0.3 to 300 mmHg which perfectly matches to the range of hypoxia. The proposed Mu relaxation method is able to detect and measure molecular O 2 concentration in tissues directly.…”

“…Muonium (bound state of  + with electron) is like an light isotopes of hydrogen. When energetic polarized positive muons are injected and stopped in water, these  + take electronic states of diamagnetic  + such as  + OH with a fraction of 60%, paramagnetic Mu with a fraction of 20% and a missing fraction of 20% (Jean et al, 1979;Nagamine and Nishiyama, 1982;Roduner et al, 1995). In the Mu fraction a half becomes ortho state with spin 1, providing a spin rotation signal with 100 times faster precession pattern with respect to the diamagnetic  + .…”

Hydrophobic solvation, quantum nature, and diffusion of atomic hydrogen in liquid water

“…Of course, in the gas and solid phases it is normal to have a mass dependence of diffusion. The question has been addressed in a comparison of the (diffusion controlled) electron spin exchange reaction of H with O 2 with that of the ultra-light hydrogen isotope muonium (Mu) with O 2 (Roduner et al, 1995b). An isotope effect of a factor of 2.070.2 in favor of the light isotope was reported, in line with the factor of 1.4170.46 reported earlier for H versus D (Benderskii et al, 1980).…”