Dipolar bonds

Clore et al. [63] have noticed that for an isotropic distribution of dipolar bond-vectors the probabilities resemble the shape of a chemical shift anisotropy powder pattern... 

DIPHTHERIA TOXIN DIPOLAR BOND DIPOLE-DIPOLE INTERACTION NONCOVALENT INTERACTLONS Dipole-dipole resonance energy transfer, FLUORESCENCE... 

Spin-spin relaxation of nuclei is accelerated when the nuclei participate in a dipolar bond (O — H, N — H, 13C—1H). Spin-spin relaxation involving dipole-dipole interaction is very effective in solids and viscous liquids with slow molecular motion, since the magnetic fields caused by slowly tumbling dipoles change very slowly. 

Dipolar bond — A bond formed (actually or conceptually) by coordination of two neutral moieties, the combination of which results in charge-separated structures, e.g.,... 

Other simple polar molecules (see Table 8.2) whose adsorption on graphite has been studied include ammonia [76—80], methanol [81, 82], and ethanol [81, 83—85]. An interesting difference between water and the alcohols is that the dipolar bonding (H-bond) network is three dimensional in bulk water but two dimensional in the alcohols where linear chains are formed. It appears that this network is disrupted in monolayer films of water, but not of the alcohols. This... 

In summary, one can conclude that a strong case can be made for the existence of at least a limited two-phase morphology for acrylic fibers. The differences in order between the two phases may be much less when compared to conventional melt-spun fibers. Furthermore, the two phases may be highly coupled since the chains in the less ordered region may be rather stiff and extended owing to the presence of the intermolecular dipolar bonds. 

The intermolecular electrostatic interactions are found in bimolecular reactions of a charged reactant approaching a molecule with strong dipolar bonds or even charges (e.g., in enzyme-catalyzed reactions, where they are used not only to properly position a substrate in the active site of an enzyme but also to lower the activation energy barrier for the subsequent chemical transformation of a substrate). 

The polarity of the molecules is usually considered to be measured on a gross scale by the relative permittivity and on a molecular scale by the electrical dipole and higher moments. Molecules lacking a dipole moment (carbon dioxide, for example) may still exert short-range effects due to quadrupole, and so on, moments. Dipolar bonds that are well separated in a molecule may act almost independently on neighboring molecules Hildebrand and Carter (1930) showed that the three isomeric dinitrobenzenes, in their binary solutions in benzene, exhibit nearly identical deviations from Raoult s law, though their dipole moments are different. The part of the electrical influence of a solvent on solute molecules that arises from the polarizability of the solvent molecules may be represented by the refractive index, n, or by functions of n such as the volume polarization, R, given by ... 

Coordinate Covalent Bond n A covalent bond in which both shared electrons appear to have been contributed by one atom. (2) coordinate link, coordinate covalent bond, dative bond, semipolar bond, or dipolar bond is a description of covalent bonding between two atoms in which both electrons shared in the bond come from the same atom. The distinction from ordinary covalent bonding is artificial, but the terminology is popular in textbooks, especially those describing coordination compounds. Once such a bond has been formed, its strength and description is no different from that of other polar covalent bonds. An example of a dipolar bond in the ammonium ion. 

In this reaction, the unshared electron pair of the base forms a coordinate covalent bond (or dative bond or dipolar bond) with an electron-deficient atom of the acid. The archetype of a Lewis acid/base reaction is... 

---