Loschmidt

Kekule s fame and his extensive contributions to chemistry as a leading German professor of his time certainly overshadowed Loschmidt. 

In 1861 Johann Josef Loschmidt who was later to become a professor at the University of Vienna pri vately published a book con taming a structural formula for benzene similar to the one Kekule would propose five years later Loschmidt s book reached few readers and his ideas were not well known... 

The work on gas theory had many extensions. In 1865 Johann Josef Loschmidt used estimates of the mean free path to make the first generally accepted estimate of atomic diameters. In later papers Maxwell, Ludwig Boltzmann, and Josiah Willard Gibbs extended the rrratherrratics beyorrd gas theory to a new gerreralized science of statistical mechanics. Whenjoined to quantum mechanics, this became the foundation of much of modern theoretical con-derrsed matter physics. 

Design of Novel Aromatics Using the Loschmidt Replacement on Graphs... 

Design of Novel Aromatics Using the Loschmidt Replacement on Graphs Y. Sritana-Anant, T. J. Seiders, J. S. Siegel... 

Rival schemes to the prism and hexagon included figures in which Josef Loschmidt used a large circle to signify neither atoms nor a ring structure for benzene but a structurally indeterminate benzene nucleus 82... 

General gas constant, R Loschmidt (Avogadro) number, N (number of particles per mol)... 

Avogadro constant Na 6.0225-lO SmoM Number of particles per mol, formerly Loschmidt number... 

Following the publication of stractural theory for all to examine, the next major players in its development were the Russian, Aleksandr Mikhailovich Butlerov (1828-1886), the Scot, Alexander Cmm Brown (1838-1922), and the Austrian, Joharm Josef Loschmidt (1821-1895). 

The third innovator of the early 1860s was the Austrian physicist Johann Josef Loschmidt, who, despite his work in chemistry, is not widely appreciated as a chemist. A portrait of him is shown in Figure 8. Loschmidt was bom in Pocena and began his university education at the German University of Prague. He completed his education at Vienna, but was unable to procure a teaching position there. He... 

Loschmidt is remembered as a physicist for his determination of the Loschmidt number 61), the number of molecules in 1 mL of gas, but in 1861 he published a small booklet 62) in which he drew stmctural formulas for a large number of organic compounds. Two formulas of the Loschmidt type are reproduced in Figure 9. It is interesting to note that, in many ways, Loschmidt s formulae reflect Dalton s elemental symbols, and may, in fact, be based on Dalton s symbolism. 

Figure 8. Johann Josef Loschmidt (1821-1895) LOSCHMIDT1861 MODERN FORMULAS... 

Figure 9. Loschmidt s structures for phenylcyanamide and the product formed from two equivalents of aniline and cyanuric chloride.

About units. For our survey of measured spectra and the comparisons with theory that follow in Chapters 5 and 6, it is useful to remember that frequencies are often expressed in units of Hertz, or of cm-1, or in cycles per 2n seconds. In order to avoid confusion we shall distinguish the notations f,v=f /c, and co = 2nf, respectively, where c designates the speed of light in vacuum. Similarly, gas densities will be expressed as number densities, n, the number of particles per volume, or in units of amagat, q = n/Na, where Na is the number of particles per cubic centimeter of the gas under consideration for most gases of interest Na is about equal to Loschmidt s number, Na Nl = 2.686763 xlO19 cm-3 amagat-1, the particle density of an ideal gas at standard temperature and pressure. The values of fundamental constants are taken from [124],... 

The other contentious issue is what might be termed the Kekule/Loschmidt controversy. Here Kekule is said to have been anticipated by J. Loschmidt in his proposal of a ring structure for benzene.134,135 Indeed one of the authors has proceeded to repeat the charge and, on the strength of researches by Kekule s biographer,... 

H. G. Winkler Chemistry and philately, Josef Loschmidt , Chem. Labor. Biotech., 1996, 47, 66-68. 

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