Factors Affecting Hydrogen-Bond Formation

The nitro group is able to form hydrogen bonds with two hydroxyl groups, as in 2-nitroresorcinol, with the structure 

Carboxyl oxygen is also effective in h3 drogen-bond formation, as in methyl salicylate, 

The possibility of forming a six-membered ring does not insure that a strong hydrogen bond will be formed, for other steric effects may 

Another interesting example has been discussed by Hilbert, Wulf, Hendricks, and Liddel, that of 3,6-dibromo-2,6-dihydroxydiethyl-terephthalate. For this substance the configuration 

Other examples of structures involving strong hydrogen bonds are given in the following sections. 

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The structure of repeat units of individual polymers constituting a blend and the nature of interactions between polymers in a blend are the factors that influence solubility characteristics of a blend. Thus, soluMlity is affected by cross-linking, hydrogen bonding, formation of donor-acceptor complexes, dipole-dipole interactions, ion-dipole interactions, ion-ion interactions, and segmental interactions. 

A proton-transfer reaction can only occur through the initial formation of a hydrogen-bonded complex and this step, although rapid, may significantly affect the kinetic analysis of a proton-transfer reaction, since a factor involving the thermodynamics of hydrogen-bond formation will be incorporated in the rate expression. 

Another property of proteins which is important in the understanding of the limits of their catalytic activity, as well as being useful in their recovery, is solubility. The solubility of globular proteins in aqueous solution is enhanced by weak ionic interactions, including hydrogen bonding between solute molecules and water. Therefore, any factor which interferes with this process must influence solubility. Electrostatic interactions between protein molecules will also affect solubility, since repulsive forces will hinder the formation of insoluble aggregates08. ... 

Other factors also affect protein stability and hyperstabihty (Vetriani et al, 1998 Jaenicke, 1996, 1998, 2000 Daniel and Danson, 2001). These include the formation of a network of surface ionic pairs, hydrogen bonding, local interactions, the stabilization of polypeptides helices (the packing and docking of domains, association of subunits, conjugation with prosthetic groups and carbohydrate moieties, etc). 

Lastly, it is conceivable that the size of the anion may have an influence over coordination polymer structure. Such an effect can be difficult to assess, and in particular, de-convolute from other factors, most noticeably from weak interactions with the polymer structure such as CH acceptor interactions. If the size of an anion is influencing a structure, it is likely that it is in close contact with the polymer and therefore the formation of hydrogen bonds, or other supramolecular interactions, could be the main factor in affecting the structure. 

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