Structure correlation principle

On the basis of the structure correlation principle Gilli postulated that the isomerization reaction path, which can be inferred from the Xn vs t correlation, proceeds along the valley of the energy surface. The valley connects the reagents (here cis isomers) and the products (here trans isomers). In order to construct the energy surface model Gilli used the equation... 

The map not only portrays the conformational space of a single isolated molecule but can also be used to plot observed torsion angles in particular structures. A collection of observed conformations will produce a scatter plot, and, according to the underlying structural correlation principle (see Chapter 5), the points will tend to congregate in regions of the conformational space associated with low energies. 

J.M. Chalmers, Spectra-structure correlations Polymer spectra. In N.J. Everall, J.M. Chalmers and PR. Griffiths (Eds.), Vibrational Spectroscopy of Polymers Principles and Practice, Wiley, Chichester, 2007. 

More generally, the relationship of structure correlations to features of the energy surface is expressed in the principle of structure correlation [16a] ... 

The examples of the second category of devices will be guided-wave optics, in which successive deposition of L-B films can be used to fabricate a waveguide or a composite waveguide. In principle, this method offers tremendous flexibility to fabricate many unusual waveguide structures. However, it is very difficult to maintain structural correlation and uniform layer-to-layer deposition for thousands of layers. Our experience has been... 

The material is presented according to the mechanistic types nucleophilic and electrophilic substitution, addition reactions, radical, pericyclic, proton and electron transfer reactions. Orbital and electrostatic models are used for structural correlations of interacting molecular systems along the reaction paths. Particular attention is focussed on the characteristics of the transition state. The text combines phenomenology with the basic theoretical principles needed to understand and predict chemical reactivity. 

The energy level in a molecule is described as the sum of the atomic and molecular motions due to translational, rotational, vibrational, and electronic energies. Translational energy has no effect on molecular spectra, whereas the other motions do affect the spectral characteristics. Rotational energy is proportional to the angular velocity of rotation for each molecule. Electronic energy in molecules and their various quantum numbers are described via the Pauli principle and are beyond the scope of this work. We will restrict our discussion to the vibrational energy levels and use the application of what is learned in this model as a basis for our specific structure-correlation characterization of near-infrared (NIR) spectra. 

Chapter 14 are available for the rigorous calculation of molecular vibrational frequencies from a given set of force constants, but are impractical for use in day-to-day chemical structure problems. There is a need for qualitative approximate methods for analyzing the nature of functional group vibrations to give meaning to simple spectra-structure correlations derived empirically. In this chapter, many applications of these qualitative principles are included, and a new application has been added on some substituted benzene vibrations. 

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