Functional groups description

The derivation of the topological distance matrix from the molecular graph is followed by the assignment of PPPs to the nodes of the graph. The following list provides chemical definitions of the five PPP types that are implemented in the CATS descriptor. The upper-case letter in parentheses is the abbreviation of each PPP type. Additionally, a functional group description is paired with its corresponding SMARTS in square brackets ... 

Functional group Description Structure Text Examples... 

In order for the transferability of parameters to be a good description of the molecule, force fields use atom types. This means that a sp carbon will be described by different parameters than a. sp - carbon, and so on. Usually, atoms in aromatic rings are treated differently from sp atoms. Some force fields even parameterize atoms for specific functional groups. For example, the carbonyl oxygen in a carboxylic acid may be described by different parameters than the carbonyl oxygen in a ketone. 

Group additivity methods must be derived as a consistent set. It is not correct to combine fragments from different group additivity techniques, even for the same property. This additivity approximation essentially ignores effects due to the location of one functional group relative to another. Some of these methods have a series of corrections for various classes of compounds to correct for this. Other methods use some sort of topological description. 

A description of the responsibilities of each functional group (e.g., duties and actions of police)... 

Much of the background needed to understand organic reactions has now been covered, and it s time to begin a systematic description of the major functional groups. Both in this chapter on alkenes and in future chapters on other... 

For a more detailed description or modeling of the surfactant properties of the alkanesulfonates it is necessary to use individual, well-defined compounds typical of the technical mixtures. Recently, new data were obtained from a series of individual homologous alkanesulfonates in which the positions of the functional group and the cations vary [38]. 

Monomers employed in a polycondensation process in respect to its kinetics can be subdivided into two types. To the first of them belong monomers in which the reactivity of any functional group does not depend on whether or not the remaining groups of the monomer have reacted. Most aliphatic monomers meet this condition with the accuracy needed for practical purposes. On the other hand, aromatic monomers more often have dependent functional groups and, thus, pertain to the second type. Obviously, when selecting a kinetic model for the description of polycondensation of such monomers, the necessity arises to take account of the substitution effects whereas the polycondensation of the majority of monomers of the first type can be fairly described by the ideal kinetic model. The latter, due to its simplicity and experimental verification for many systems, is currently the most commonly accepted in macromolecular chemistry of polycondensation processes. 

J. N. Hogsett, cf., method description in F. E. Critchfield, Organic Functional Group Analysis (International Series of Monographs on Analytical Chemistry, Vol. 8), Pergamon Press, Oxford, 1963, p. 95. 

The first chapter Heterophenes Carrying Phosphorus Functional Groups as Key Structures presents a detailed description of the recent advances made in this field. The recent studies of all-phosphorus-substituted aromatic compounds have revealed some unique properties of these heterocycles. 

The final part is devoted to a survey of molecular properties of special interest to the medicinal chemist. The Theory of Atoms in Molecules by R. F.W. Bader et al., presented in Chapter 7, enables the quantitative use of chemical concepts, for example those of the functional group in organic chemistry or molecular similarity in medicinal chemistry, for prediction and understanding of chemical processes. This contribution also discusses possible applications of the theory to QSAR. Another important property that can be derived by use of QC calculations is the molecular electrostatic potential. J.S. Murray and P. Politzer describe the use of this property for description of noncovalent interactions between ligand and receptor, and the design of new compounds with specific features (Chapter 8). In Chapter 9, H.D. and M. Holtje describe the use of QC methods to parameterize force-field parameters, and applications to a pharmacophore search of enzyme inhibitors. The authors also show the use of QC methods for investigation of charge-transfer complexes. 

Introduction of new precursor architectures brings about new challenges in description and modeling of network formation because the apparent reactivities of functional groups become dependent on the size and shape of the precursors... 

As such, a more thorough description of the energetics of nitroso compounds may well logically appear in a future Patai volume on functional groups devoted to carbon-containing double bonds such as monoalkenes, imines and ketones and aldehydes, since oximes would seem to belong with these functionalities. 

Almost every elementary textbook of organic chemistry provides a systematic description of properties of functional groups and their characteristic reactivity for example,... 

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