Hydrogen theory

This system of nomenclature has withstood the impact of later experimental discoveries and theoretical developments that have since the time of Guyton de Morveau and Lavoisier greatiy altered the character of chemical thought, eg, atomic theory (Dalton, 1802), the hydrogen theory of acids (Davy, 1809), the duahstic theory (Berzehus, 1811), polybasic acids (Liebig, 1834), Periodic Table (Mendeleev and Meyer, 1869), electrolytic dissociation theory (Arrhenius, 1887), and electronic theory and modem knowledge of molecular stmcture. 

J. van Kranendonk, Solid Hydrogen Theory of the Properties of Solid Hj, HD, and D2, Plenum, New York, 1983. 

The photoexcitation of nonhydrogenic atoms is in many ways similar to the photoexcitation of H. For example, the strong field mixing resonances observed in Rb, Ba, and Na are well described by a hydrogenic theory.6,7,13 However, all features of the photoexcitation spectra of nonhydrogenic atoms are not equally well described by a hydrogenic theory, and we now describe the deviations. It is convenient to consider three spectral regions, below the classical ionization limit, above the classical ionization limit but below the zero field limit, and above the zero field limit. 

The half hydrogenation theory [5, 6] predicts that, the higher the hydrogen concentration at the catalyst, the lower the formation of trans-fatty acids. The theory has been verified by many experiments [e.g. 7, 8]. 

The alpha-hydrogen theory has been set up on the basis of a series of investigations of compounds with auxin action. According to this theory, phenoxy-, naphthoxy-, naphtho- and fluorenecarboxylic acid derivatives are active only if there is a hydrogen atom at the carbon atom adjacent to the carboxyl group (Osborne and Wain, 1949 Wain, 1953 Fawcett et al 1955b). 

While the isolation of des-base-A as one of the products of the Hofmann reaction has added further support for the structure assigned to methyl-(chano)-dihydroneostrychnidine, yet it is the isomeric des-base, anhydro-methylstrychnidinium-D hydroxide (des-base-D, m.p. 196-197°) that has provided a whole series of new compounds by a novel reaction. Introduction of two hydrogen atoms into des-base-D by catalytic reduction (palla-A solution of 9.0 g. of des-basc-D in 130 cc. of 10% hydrochloric acid is shaken with hydrogen at 17-19° in the presence of palladium-charcoal catalyst. The uptake of hydrogen ceases when 355 cc. of hydrogen (theory 600 cc.) is absorbed. Further addition fails even at 90°. The hot solution is filtered, made ammoniacal, and concentrated under vacuum to one-third its volume. The concentrate, when treated with a solution of 10 g. of sodium iodide in 10 cc. of water, yields a colorless precipitate which is a mixture of methyldihydrostrychnidinium-D iodide and methyldihydrostrychnidinium-A iodide. Repeated fractional crystallization from water yields 8.7 g. of the former (m.p. 325-327°) and 3.2 g. of the latter (m.p. 345-350°). 

The initial stages of rare earth metal hydrogenation theory... 

The Graham-Liebig work on polybasic acids added a fifth strand to the four interconnected developments discussed in the last section—chlorine substitution, type theory, a modified radical theory, and the hydrogen theory of acidity—all of which worked against electrochemical-dualist theory. A molecule of a polybasic acid, in Liebig s hands, was depicted as a molecular entity that could hold together additional molecular components it formed the hub, as it were, of a more complex molecule. It appears that Williamson likewise saw Graham s work on phosphoric acids in this way, for in an obituary of... 

Thomas Clark (see p. 272) had taught the hydrogen theory of acids in his lectures in 1826 in the Mechanics Institution in Glasgow, and published some tables for the use of his students, in which he uses the atomic weights azote A = 7, carbon C = 6, chlorine Ch = i8, hydrogen oxygen 0=8,... 

In 1837 Liebig and Dumas met in Paris. Liebig had been asked by the British Association to produce a report on the present state of organic chemistry and their first joint paper dealt with this, Dumas having accepted the ethyl theory. The second paper dealt with the hydrogen theory of acids. ... 

Dumas and Liebig, Note sur l 6tat actuel de la Chimie organique Compt, Rend.y 1837, v, 567 id,y ib,y 1837, V, 863-6 Note sur la constitution de quelques acides y. prakt. Chem.y 1838, xiv, 304-7 (Liebig s hydrogen theory of acids). 

Similar measurements of d-f and d-g intervals in lithium Rydberg states by Cooke et yielded fine structure intervals in accordance with the hydrogenic theory. Ruff and co-workers measured n = 15-17 f-g intervals in Cs and determined values for the effective Cs dipole and quadrupole polarizabilities. To reach the Rydberg levels the first laser excited atoms from the 6si/2 ground state to the lp-i/2 state, from which they cascaded to the 5ds/2 level. The second laser then induced the 5ds/2-16/7/2 transition. This excitation technique was first used by Lundberg and Svanberg for lifetime measurements. ... 

---