Bond, covalent strength, electrostatic

What gives the covalent bond its strength It is the increase in electrostatic attraction. In the isolated atoms, each electron is attracted by—and attracts— one positive nucleus in the molecule, each electron is attracted by two positive nuclei. 

Noncovalent Bonds. Noncovalent bonds are weaker than covalent bonds but arc crucial for biochemical processes such as the formation of a double helix, hour lundamental noncovalent bond types are electrostatic interactions, hydrot en bonds, van der Waals interactions, and hydrophobic inlerac-turns. T hey differ in geometry, strength, and specificity. Furthermore, these bunds are allected in vastly different ways by the presence of water. Let us consider the characteristics of each ... 

Contrary to what has been reported for non-covalently binding mucoadhesive polymers, the disulfide bond is not influenced by ionic strength, electrostatic, or hydrophobic domain interactions." The extent of the disulfide bond is strictly related to the concentration of thiolate anions, which is the group that will go through thiol/disulfide exchange reactions and oxidation processes. The concentration of the thiolate groups is mostly determined by the p T value of the thiol group. 

Hydrogen bond is purely electrostatic in nature formed between the positive end of one molecule (dipole) and negative end of another molecule (or even same molecule). It can be considered as a special case of strong dipole-dipole attraction. The strength of hydrogen bond is about 10-40 kJ moT which is much less than that of a pure covalent bond (400 kJ mol" ). 

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