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  2. Aspirin - Wikipedia

    en.wikipedia.org/wiki/Aspirin

    In form II, each aspirin molecule forms the same hydrogen bonds, but with two neighbouring molecules instead of one. With respect to the hydrogen bonds formed by the carboxylic acid groups, both polymorphs form identical dimer structures. The aspirin polymorphs contain identical 2-dimensional sections and are therefore more precisely described ...

  3. Hydrogen bond - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_bond

    Consequently, hydrogen bonds between or within solute molecules dissolved in water are almost always unfavorable relative to hydrogen bonds between water and the donors and acceptors for hydrogen bonds on those solutes. [44] Hydrogen bonds between water molecules have an average lifetime of 10 −11 seconds, or 10 picoseconds. [45]

  4. Acetylation - Wikipedia

    en.wikipedia.org/wiki/Acetylation

    The modification results in bonds between the structural polymeric components, significantly reducing the ability of the -OH groups to form hydrogen bonds with water molecules. This effectively "locks" the cellular walls, minimizing the capacity of wood to absorb water and enhancing its dimensional stability.

  5. Properties of water - Wikipedia

    en.wikipedia.org/wiki/Properties_of_water

    Water molecules stay close to each other , due to the collective action of hydrogen bonds between water molecules. These hydrogen bonds are constantly breaking, with new bonds being formed with different water molecules; but at any given time in a sample of liquid water, a large portion of the molecules are held together by such bonds. [61]

  6. Lipinski's rule of five - Wikipedia

    en.wikipedia.org/wiki/Lipinski's_Rule_of_Five

    No more than 5 hydrogen bond donors (the total number of nitrogen–hydrogen and oxygen–hydrogen bonds) No more than 10 hydrogen bond acceptors (all nitrogen or oxygen atoms) A molecular mass less than 500 daltons; A calculated octanol-water partition coefficient (Clog P) that does not exceed 5

  7. Chemical bonding of water - Wikipedia

    en.wikipedia.org/wiki/Chemical_bonding_of_water

    Lewis Structure of H 2 O indicating bond angle and bond length. Water (H 2 O) is a simple triatomic bent molecule with C 2v molecular symmetry and bond angle of 104.5° between the central oxygen atom and the hydrogen atoms.

  8. Grotthuss mechanism - Wikipedia

    en.wikipedia.org/wiki/Grotthuss_mechanism

    Protons tunnel across a series of hydrogen bonds between hydronium ions and water molecules.. The Grotthuss mechanism (also known as proton jumping) is a model for the process by which an 'excess' proton or proton defect diffuses through the hydrogen bond network of water molecules or other hydrogen-bonded liquids through the formation and concomitant cleavage of covalent bonds involving ...

  9. Hydrogen compounds - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_compounds

    Water molecules have two hydrogen atoms and one oxygen atom. While H 2 is not very reactive under standard conditions, it does form compounds with most elements. Hydrogen can form compounds with elements that are more electronegative, such as halogens (F, Cl, Br, I), or oxygen; in these compounds hydrogen takes on a partial positive charge. [1]