Intermolecular hydrogenation

Photoinitiators which abstract hydrogen intermolecularly from a polymer (PH) molecule ... 

The reader should note that, in case of centrosymmetric structures the term z=0, and the Kirkwood factor is 1. In this case Ac provides no information about the average orientational order. However, that does not occur for our samples, because poliols ar linear chains and very unlikely they can form centrosymmetric stmctures via hydrogen intermolecular bondings... 

Bfi and 022- However, in the second binary, intermolecular forces between unlike molecules are much stronger than those between like molecules chloroform and ethyl acetate can strongly hydrogen bond with each other but only very weakly with them-... 

The different kinds of intermolecular forces (dispersion, dipole-dipole, hydrogen bonding, etc. see Section VI-1) may not equally contribute to A-A, B-B, and A-B... 

Gavezzotti A and Filippini G 1994 Geometry of the intermolecular XH.. . Y (X,Y = N,0) hydrogen bond and the calibration of empirical hydrogen-bond potentials J. Phys. Chem. 98 4831... 

The dotted lines represent hydrogen bonds. The high boiling point and viscosity of the pure acid indicate strong intermolecular forces of this kind. 

In aqueous solution intermolecular association between carboxylic acid molecules IS replaced by hydrogen bonding to water The solubility properties of carboxylic acids are similar to those of alcohols Carboxylic acids of four carbon atoms or fewer are mis cible with water m all proportions... 

Polymer alloys are physical mixtures of structurally different homopolymers or copolymers. The mixture is held together by secondary intermolecular forces such as dipole interaction, hydrogen bonding, or van der Waals forces. 

Frohlich, H. Using Infrared Spectroscopy Measurements to Study Intermolecular Hydrogen Bonding, /. Chem. Educ. 1993, 70, A3-A6. 

The term polymer is derived from the Greek words poly and meros, meaning many parts. We noted in the last section that the existence of these parts was acknowledged before the nature of the interaction which held them together was known. Today we realize that ordinary covalent bonds are the intramolecular forces which keep the polymer molecule intact. In addition, the usual type of intermolecular forces—hydrogen bonds, dipole-dipole interactions, and London forces—hold assemblies of these molecules together in the bulk state. The only thing that is remarkable about these molecules is their size, but that feature is remarkable indeed. 

The various mechanical properties of polyamides may be traced in many instances to the possibility of intermolecular hydrogen bonding between the polymer molecules and to the relatively stiff chains these substances possess. The latter, in turn, may be understood by considering still another equilibrium, this one among resonance structures along the chain backbone ... 

Partial glycerides tend to melt higher than thek triglyceride counterparts, as shown in Figure 6. This observation is consistent with the presence of free hydroxyl groups which can participate in increased intermolecular hydrogen bonding. 

Substitution of fluorine for hydrogen in an organic compound has a profound influence on the compound s chemical and physical properties. Several factors that are characteristic of fluorine and that underHe the observed effects are the large electronegativity of fluorine, its small size, the low degree of polarizabiHty of the carbon—fluorine bond and the weak intermolecular forces. These effects are illustrated by the comparisons of properties of fluorocarbons to chlorocarbons and hydrocarbons in Tables 1 and 2. 

The physical properties of hydrofluorocarbons reflect their polar character, and possibly the importance of intermolecular hydrogen bonding (3). Hydrofluorocarbons often bod higher than either their PFC or hydrocarbon counterparts. For example, l-C H F bods at 91.5°C compared with 58°C for n-Q and 69°C for Within the series of fluorinated methanes, the boiling point reaches a maximum for CH2F2, which contains an equal... 

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