Substituent properties

A -substituents. properties, 33 Nuclear magnetic resonance, of 13 C. in polymethine dyes, 72 of proton, in polymethine dyes. 72... 

Skeletal properties Substituent properties Polymer properties... 

Skeletal Properties Type of Substituent Substituent Properties Final Polymer Properties... 

These findings point to a general problem of the triafulvene system, namely that its degree of polarity is considerably affected by C4-substituent properties as in the case of quinocyclopropenes 198/199 by the different aromatization tendency of the quinonoid system. 

The model will break down if non-linear dependence on substituent properties is important or if there are interactions between the substituents. 

A second example of the correlation of isotope effects with substituent properties is given by the reaction between -substituted N,N-dimethylanilines and methyl iodide illustrated in Fig. 10.8.2°-ot-D and incoming group nitrogen KIE s are collected in Table 10.7. 

Ertl, P. Cheminformatics analysis of organic substituents identification of the most common substituents, calculation of substituent properties, and automatic identification of dmg-like bioisosteric groups. J. Chem. Inf. 

No correlation with substituent properties can be recognized for the fi effect of halogens in Table 3.2. The magnitude of shielding due to the y effect, however, decreases with increasing size of the halogen (Table 3.2). A reduced population of the gauche conformer... 

In contrast to the qualitative better and worse approach of traditional SAR, many researchers have sought to develop a method that is able to quantitatively link molecular structure changes to biological activity, a quantitative structure-activity relationship (QSAR). As a method, QSAR strives to develop a mathematical formula to relate biological activity as a function of molecular or substituent properties. 

A partition coefficient is a property of a whole molecule. To define 7tr, a substituent property, Hansch compared the partition coefficient of a substituted compound with an unsubstituted compound (Equation 12.13). 

The review consists of five parts, of which the first is a general survey of the substituent properties of cyclopropyl, and the detection and consequences of conjugative interactions of cyclopropyl. The second and third parts involve a more specific discussion of the influence cyclopropyl has on heteroatom and carbon functionalities, respectively. Part... 

The substituent properties of the cyclopropyl group have been assessed by a number of physical methods, including measurements of ionization potentials, ultraviolet spectroscopy, infrared and Raman spectroscopy, nuclear magnetic resonance, mass spectra , dipole moments, and thermochemistry, and the results of these studies up until 1970 were thoroughly covered by Charton Several of these topics are discussed in detail in separate chapters of this volume, but particular results are cited here when appropriate to illustrate the conjugative powers of cyclopropyl and its use as a probe for reaction mechanisms. 

Conjugative and substituent properties of the cyclopropyl group 593 TABLE 12. Calculated bond lengths (A) for C4H7 structures... 

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