Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Substituents specific

Figure 2.1 provides a quick overview of the basic chemical shift ranges for carbon-bound F, CF2, and CF3 substituents. Specific details... [Pg.26]

Substituents Specific rate constant Solvent (liter mole-1 sec-1) Ea (kcal mole-1) JS (e.u.)... [Pg.396]

Bowden-Wooldridge steric constant -> steric descriptors (O number of atoms in substituent specific positions)... [Pg.32]

As with the three polymeric examples, bipyridine ligands have been incorporated into polypeptides at the chain end, in the backbone, and as attached substituents. Specifically, a bipyridine has been coupled to either the amino or acid terminus of polypeptides to afford biological macroligands. For example, the 4,4 -dicarboxylic acid bipyridine was coupled to two 14-unit o-helices in order to analyze the conformation of the parallel structures.272 A triple-helical synthetic metallo-protein was formed through metal-templated self-assembly of a bipyridine unit with a 15-residue peptide substituted in the presence of metal ions.273... [Pg.22]

Cj building blocks, where is a heterosubstituent other than halogen, are mentioned briefly where appropriate, but are discussed in detail in the sections dealing with these substituents specifically. [Pg.405]

The main difficulties associated with constructing the biaryl moiety as a single atropisomer early in the synthesis lies within the arene substitution pattern. The thermal isomerization barrier for a steganone precursor that carries only three ortho substituents is extremely sensitive to the exact identity of those substituents. Specifically, when one of the three groups (e.g., a formyl moiety) adds only a small amount to the inversion barrier and a second substituent (e.g., a methoxy group) is also relatively small, the barrier to inversion renders the biaryl stereochemically labile even at 0 For example, at least one of... [Pg.151]

For the purpose of characterizing chemicals for designing and selecting training sets for QSAR analyses, a values can be retrieved from tabulations (e.g. Perrin, Dempsey and Serjeant, 1981 Hansch, Leo and Taft, 1991). If several substituents are present on a parent structure, the sum of the corresponding cr values is used. Especially for c>-substituents, specific (rvalues for the given chemical class have to be used. [Pg.31]

Alkyl substituents (specifically the octadecyl ODS form) are the most common bonded groups these convert the surface polar hydroxyl groups to a markedly hydrophobic surface upon which chromatography occurs. Elution is carried out with polar solvents such as water and methanol there is a polarity reversal of the stationary and moving phases compared with conventional liquid chromatography on silica, hence the term reverse-phase HPLC. [Pg.276]


See other pages where Substituents specific is mentioned: [Pg.152]    [Pg.136]    [Pg.111]    [Pg.123]    [Pg.136]    [Pg.46]    [Pg.235]    [Pg.88]    [Pg.111]    [Pg.123]    [Pg.396]    [Pg.339]    [Pg.380]    [Pg.404]    [Pg.415]    [Pg.343]    [Pg.235]    [Pg.136]    [Pg.565]    [Pg.658]    [Pg.705]    [Pg.741]    [Pg.396]    [Pg.136]    [Pg.273]    [Pg.212]    [Pg.33]    [Pg.155]    [Pg.942]    [Pg.186]    [Pg.1719]    [Pg.268]    [Pg.697]   
See also in sourсe #XX -- [ Pg.113 , Pg.114 , Pg.115 , Pg.116 , Pg.117 , Pg.118 , Pg.119 , Pg.120 , Pg.121 , Pg.122 ]

See also in sourсe #XX -- [ Pg.113 , Pg.114 , Pg.115 , Pg.116 , Pg.117 , Pg.118 , Pg.119 , Pg.120 , Pg.121 , Pg.122 ]




SEARCH



Structure-activity relationships specific substituent groups

Substituents specific substitution

© 2024 chempedia.info