Tritium atomic properties

Table 3.1 Atomic properties of hydrogen (protium), deuterium, and tritium...

Isotopic exchange in most cases does not greatly influence the physico-chemical properties of the total compound. In the case of tritium for hydrogen exchange however, the isotope effect of tritium can influence the pKA of a basic moiety in the vicinity of the tritium atom [1,2]. Although only a small shift in the pKA is observed (0.05-0.1), this can be of great importance for the biological activity of a radiopharmaceutical. 

The results concerning the allowance for the / -source molecular structure (Kaplan et al., 1982,1983) were used in reduction of the new experimental data obtained by the ITEP group. Table I (Boris et al., 1983) shows the most probable values of the neutrino rest mass obtained by data reduction using the models of a bare nucleus, of a tritium atom, and of a real valine molecule. The reduction of the new experimental data within the bare-nucleus model did not lead to a nonzero rest mass of the neutrino. The allowance for the electron structure of valine gives mvc2 = 33 eV.2 Thus, the quantum chemical calculations proved to be a necessary step in the reduction of the data concerning the properties of an elementary particle. 

Tetrahedral intermediates derived from carboxylic acids, spectrosopic detection and the investigation of their properties, 21, 37 Topochemical phenomena in solid-state chemistry, 15, 63 Tritiated molecules, gaseous carbonium ions from the decay of 8, 79 Tritium atoms, energetic, reactions with organic compounds, 2, 201 Turnstile rearrangements in isomerization of pentavalent phosphorus compounds, 9, 25... 

For example, there are three distinct kinds of hydrogen atoms, commonly called hydrogen, deuterium, tritium. (This is the only element for which we give each isotope a different name.) Each contains one proton in the atomic nucleus. The predominant form of hydrogen contains no neutrons, but each deuterium atom contains one neutron and each tritium atom contains two neutrons in its nucleus (Table 5-2). All three forms of hydrogen display very similar chemical properties. 

Table 1. Some atomic properties of protium, deuterium and tritium.

Tritium water HTO ( H20) consists of a tritium atom, which is an isotope of hydrogen, an oxygen atom and a normal hydrogen atom. The chemical property is almost same as the normal water H2O, and in a bentonite saturated with normal... 

Hydrogen as it occurs in nature is predominantly composed of atoms in which the nucleus is a single proton. In addition, terrestrial hydrogen contains about 0.0156% of deuterium atoms in which the nucleus also contains a neutron, and this is the reason for its variable atomic weight (p. 17). Addition of a second neutron induces instability and tritium is radioactive, emitting low-energy particles with a half-life of 12.33 y. Some characteristic properties of these 3 atoms are given in Table 3.1, and their implications for stable isotope studies, radioactive tracer studies, and nmr spectroscopy are obvious. 

Electronically excited states of organic molecules, acid-base properties of, 12,131 Energetic tritium and carbon atoms, reactions of, with organic compounds, 2, 201 Enolisation of simple carbonyl compounds and related reactions, 18,1 Entropies of activation and mechanisms of reactions in solution, 1,1 Enzymatic catalysis, physical organic model systems and the problem of, 11, 1 Enzyme action, catalysis of micelles, membranes and other aqueous aggregates as models of, 17. 435... 

Electronically excited states of organic molecules, acid-base properties of, 12, 131 Energetic tritium and carbon atoms, reactions of, with organic compounds, 2, 201... 

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