Polar functional groups

What does functional-group polarity mean with respect to chemical reactivity Because unlike charges attract, the fundamental characteristic of all polar organic reactions is that electron-rich sites react with electron-poor sites. Bonds are made when an electron-rich atom shares a pair of electrons with an electron-poor atom, and bonds are broken when one atom leaves with both electrons from the former bond. 

However, it was immediately recognized by peptide chemists that, even in the cases where a direct (backbone)peptide -protein(backbone) interaction is not operative, the backbone conformation may dramatically influence the biological response. It is evident that the introduction of new, promising peptidomimetics is based primarily on the combined knowledge of the complementary conformational, topochemical, and electronic properties of the native peptide and of its address (in other words, of the receptor or the active site of the enzyme with which it interacts). Then, the design of peptidomimetics as potential bioactive compounds must take into particular account two structural factors (i) a favorable fit (tertiary structure) with respect to the corresponding complementary spatial situation at the active site (ii) the placement of structural elements (e.g., functional groups, polar and... 

Within any functional group, polarity decreases rapidly as the length of the nonpolar carbon chain increases. The polarity of mixed solvents is intermediate between the respective polarities of individual solvents of which they are composed. 

Dong Y, Tang Y, Chollet J, Matile H, Wittlin S, Charman SA, Charman WN, Tomas JS, Scheurer C, Snyder C, Scorneaux B, Bajpai S, Alexander SA, Wang X, Padmanilayam M, Cheruku SR, Brun R, Vennerstrom JL. Effect of functional group polarity on the antimalarial activity of spiro and dispiro-l,2,4-trioxolanes. Bioorg. Med. Chem. 2006 14 6368-6382. 

In normal-phase chromatography (NPC), the stationary phase is polar. A nonpolar mobile phase is used, such as n-hexane, methylene chloride, or chloroform. The stationary phase is a bonded siloxane with a polar functional group (polarity order cyano < diol < amino < dimethylamino). These phases retain polar compounds in preference to nonpolar compounds. 

Non-chemically ampliflied positive resists based on functional group polarity switch... 

A shown in Fig. 7.1, there are two hroad categories of chemical amplification resists based on their imaging mechanisms, namely, (i) those based on acid-catalyzed main chain scission and (ii) those based on functional group polarity switch brought about by acid-catalyzed deprotection of lipophilic pendant groups, depolymerization, and Claisen rearrangement. 

The most widely used methods to predict aqueous solubility from molecular structure are quantitative structure-property relationships (QSPRs) [4-6], which are empirical models that use experimental data to learn a statistical relationship between the physical property of interest (i.e., solubility) and molecular descriptors calculable from a simple computational representation of the molecule (e.g., counts of atoms or functional groups, polar surface area, and molecular dipole moment) [1], The current... 

The unique feature in core 3 is the presence of two contiguous sp stereocenters that confer a cylinder-like shape on the molecule around the C-C axis. Appending different functional groups (polar, nonpolar etc.) around each sp ... 

What does functional-group polarity mean with respect to chemical reactivity Because unlike charges attract, the fundamental characteristic of all polar... 

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