Topochemical definition

Fig. 6 Stacking model for the muconate derivatives in the crystalline state and the definition of stacking parameters used for the prediction of the topochemical polymerization reactivity, d c the intermolecular distance between the 2 and 5 carbons, is the stacking distance between the adjacent monomers in a column. 6 and 02 are the angles between the stacking direction and the molecular plane in orthogonally different directions [59]...

On first glance this seems consistent with our definition above. However, the topochemical principles, first enunciated by Cohen and Schmidt (1964a) Cohen et al. (1964c) were acmally developed from the fact that different polymorphs of a substance (trans cinnamic acid) undergo different photochemicaZ reactions, leading to different products Schmidt (1964) (Section 6.4). 

ETA indices are an extension of the TAU indices (or Topochemically Arrived Unique indices) [Pal, Purkayastha et al, 1992 Pal, Sengupta et al, 1988,1989,1990], which were defined some years before in the framework of a previous version of the Valence Electron Mobile environment (VEM environment). TAU indices are calculated from previous definitions of core count and VEM count and include four indices the composite topochemical index, denoted by T (similar to the composite ETA index), the functionality index, denoted by F, the skeletal index, denoted by Tr, and the simple branching index, denoted by B. In QSAR studies, these indices were used in combination with —> STIMS indices, connectivity indices, and some information indices [Roy, Pal et al, 1999, 2001]. 

Topotactic processes are described more comprehensively in Mechanical Preparation of Crystalline Materials. An Oxymoron and Templated [2 + 2] Photodimerizations in the Solid State, Supramolecular Materials Chemistry. Since its original definition in 1959, the term topotaxy has evolved " to mean a solid-state chemical reaction (not necessarily reversible) that completely transforms a single crystal such that the product resembles that of the initial material both in terms of its three-dimensional structure and the orientation thereof. Topotactic is synonymous with topochemical... 

Clathrates, or inclusion components (host), pack the molecules of second component (guest) into lattice, generating a definite crystalline stmcture. The most important aspect of polymerization in clathrates deals with possible topochemical control. 

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