On the Theory of Resonance

The strength of the bonding found in the actual structure III is greater than that calculated for either of the imaginary structures I and II. This has been explained on the theory of resonance based... 

We present here a summary of our work on the collision dynamics of three Interacting atoms, (O adding new developments on the theory of resonances in rearrangement collisions. We begin by showing how to go from a description In terms of electrons and nuclei to one... 

Since in those days there were no university laboratory facihties, Strutt established his own at the family home, Terling Place. There he started research in electrodynamics, color vision, radiation scattering, acoustics, and other experimental phenomena that could be explained in terms of wave motion. In 1870 he pubhshed his classic paper On the Theory of Resonance that estabhshed Strutt s reputation as a serious scientist capable of handling both experimental and mathematical problems. In 1871 he followed up with his well-known theory of light scattering by small particles (now called Rayleigh scattering) and explained how this phenomenon is responsible for the blue color of the sky. 

Linus Pauling (1901 1994) made many contributions to our knowledge of organic structures. He did ftmda-mental work on the theory of resonance, on the measurement of bond lengths and energies, and on the structure of proteins and the mechanism of antibody action. He received the Nobel Prize in chemistry in 1954 and the Nobel Peace Prize in 1962. 

Page J B and Tonks D L 1981 On the separation of resonance Raman scattering into orders in the time correlator theory J. Chem. Phys. 75 5694-708... 

L. Mandelstam and N. Papalexi were first to establish the theory of the subharmonic resonance based directly on the theory of Poinear6 (Section 6.18). The derivation of this theory, together with the details of the electronic circuits, is given in25, or in an abridged version in6 (pages 464-473). The difficulty of the problem is due to the fact that this case is nonautonomous so that conditions of stability are determined in terms of the characteristic exponents, which always leads to rather long calculations. 

The activated complex can be described as involving resonance of the fourth bond of carbon between the hydroxyl and iodine ions. Some very interesting rough quantum-mechanical calculations bearing on the theory of chemical reactions have been made of Eyring and Polanyi and their collaborators. It is to be hoped that the quantitative treatments can be made more precise and more-reliable but before this can be done effectively there must take place the extensive development of the qualitative theory of chemical reactions, probably in terms of resonance. 

In sharp contrast to cyclopentadiene is cycloheptatriene (41), which has no unusual acidity. This would be hard to explain without the aromatic sextet theory, since, on the basis of resonance forms or a simple consideration of orbital overlaps. 

The polar character of the group R will also have a bearing on the formation and stabilization of the furan ring. In accordance with the theory of resonance, the classic structure... 

Linus Pauling, "The Nature of the Theory of Resonance," 18, in [Sir] Alexander Todd, ed., Perspectives in Organic Chemistry (New York Interscience Publishers, 1956) 67, regarding Ingold and Ingold (1926), 1312. Todd s volume is dedicated to Robert Robinson on the occasion of his seventieth birthday, September 13, 1956. 

Classical structure theory was developed purely from chemical facts, without any help from physics. The theory of resonance was well on its way toward formulation before quantum mechanics was discovered.. . . ... 

Recognition has been made of some rather strongly worded criticism, from various sides, of the treatment of resonance of molecules among alternative valence-bond structures, as presented in earlier editions of this book, on the basis of its idealistic and arbitrary character, by the introduction of a section (Sec. 6-6) in which it is pointed out that the theory of resonance involves only the same amounts of idealization arid arbitrariness as the classical valence-bond theory. 

The contributions of Erich Hiickel to the development of molecular orbital theory have already been mentioned in the subsection on Germany (Section 5.4.1) the development of semi-empirical quantum mechanical treatments in organic chemistry by M. J. S. Dewar has been discussed in Section 5.5. In the early development of the application of quantum mechanics to chemistry, Linus Pauling (1901-1994)359 was pre-eminent. He was associated with CalTech for most of his career. His work before World War II generated two influential books the Introduction to Quantum Mechanics (with E. Bright Wilson, 1935)360 and The Nature of the Chemical Bond (1939).361 He favoured the valence-bond treatment and the theory of resonance. 

Resonance, strictly speaking, is not a real physical phenomenon but only an interpretation, as a consequence of the way in which the wave function of the stationary state, for example of the benzene molecule, can be constructed approximately by linear combination of other wave functions. This construction is possible in a way which fits in well with the interpretation of these systems based on the theory of chemical structure. 

The influence of molecular structures and substituents on the antiozonant properties of a series of related aromatic diamine compounds was studied. The relative effectiveness of the compounds was determined by viscometric techniques and by comparison of the rate of degradation of protected vuicanizates. Results indicate that unsymmetrical p-phenylenediamine derivatives are less effective than analogous symmetrical compounds as antiozonants. The protective capacity of the antiozonants decreases as the size or number of the N-hydrogen substituents, or the distance between the amine groups, increases. The comparative stability of the free radicals of aryl diamines, in terms of the theory of resonance, is utilized to explain the relative inhibiting properties of the chemicals examined. 

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