Electrotopological states

Some further topological descriptors are the Kier-Hall connectivity indices [13] and the electrotopological state index (or -state index) [14]. A comprehensive overview of topological molecular desaiptors is given by Todeschini and Consonni [15]. 

B Mohney and L B Kier 1991. The Electrotopological State An Atom Index for QSAR. ntitative Structure-Activity Relationships 10 43-51. 

L. B. Kiel, L. H. Hall, Molecular Structure Description The Electrotopological State Academic Press, San Diego (1999). 

Kier LB, Hall LH. Molecular structure description the electrotopological state. San Diego Academic Press, 1999. 

Kier, L. B., Hall, L. H. The electrotopological state Structure modeling for QSAR and database analysis. 

Hall, L. H., Mohney, B Kier, L B. The electrotopological state Structure information at the atomic level for molecular graphs. J. Chem. Inf. Comput. Set. 1991, 31, 76-82. 

Voelkel, A. Structural descriptors in organic chemistry - new topological parameter based on electrotopological state of graph vertices. Comput. Chem. 1994, 18, 1. ... 

Huuskonen, J., Rantanen, J., Livingstone, D. Prediction of aqueous solubility for a diverse set of organic compounds based on atom-type electrotopological state indices. Eur. J. Med. Chem. 2000, 35, 1081-1088. 

Rose, K., Hall, L. H., Kier, L. B. Modeling blood-brain barrier partitioning using the electrotopological state. /. Chem. Inf. Comput. Sci. 2002, 42, 551-556. 

Norinder, U., Osterberg, T. Theoretical calculation and prediction of drug transport processes using simple parameters and partial least squares projections to latent structures (PLS) statistics. The use of electrotopological state indices./. Pharm. Sci. 2001, 90, 1075-1085. 

Atom Contribution Methods, Electrotopological State (E-state) Indices and CCMs... 

I. V. Neural network modeling for estimation of partition coeffident based on atom-type electrotopological state indices. 

Huuskonen,. J., Villa, A. E., Tetko, I. V. Prediction of partition coeffident based on atom-type electrotopological state indices. f Pharm. Sci. 1999, 88, 229-233. 

Ovidiu Ivanciuc describes the computation of Electrotopological State (E-state) Indices from the molecular graph and their application in drug design. The E-state encodes at the atomic level information regarding electronic state and topo-... 

L. B., The electrotopological state structure information at the atomic level for molecular graphs, J. Chem. 

Another set of particularly useful 2D-based topological descriptors are the so-called electrotopological state index (E-state) descriptors developed by Kier and Hall [36],... 

At the low end of the hierarchy are the TS descriptors. This is the simplest of the four classes molecular structure is viewed only in terms of atom connectivity, not as a chemical entity, and thus no chemical information is encoded. Examples include path length descriptors [13], path or cluster connectivity indices [13,14], and number of circuits. The TC descriptors are more complex in that they encode chemical information, such as atom and bond type, in addition to encoding information about how the atoms are connected within the molecule. Examples of TC descriptors include neighborhood complexity indices [23], valence path connectivity indices [13], and electrotopological state indices [17]. The TS and TC are two-dimensional descriptors which are collectively referred to as TIs (Section 31.2.1). They are straightforward in their derivation, uncomplicated by conformational assumptions, and can be calculated very quickly and inexpensively. The 3-D descriptors encode 3-D aspects of molecular structure. At the upper end of the hierarchy are the QC descriptors, which encode electronic aspects of chemical structure. As was mentioned previously, QC descriptors may be obtained using either semiempirical or ab initio calculation methods. The latter can be prohibitive in terms of the time required for calculation, especially for large molecules. 

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