Dipole moments dependence

The magnitude of the induced dipole moment depends on the electric field strength in accord with the relationship = nT, where ]1 is the induced dipole moment, F is the electric field strength, and the constant a is caHed the polarizabHity of the molecule. The polarizabHity is related to the dielectric constant of the substance. Group-contribution methods (2) can be used to estimate the polarizabHity from knowledge of the number of each type of bond within the molecule, eg, the polarizabHity of an unsaturated bond is greater than that of a saturated bond. 

This dispersion interaction must be added to the dipole-dipole interactions between molecules, such as HCl, NH3 and H2O which have a permanent dipole, fi. The magnitude of die dipole moment depends on tire differences in electronegativity of the atoms in the molecule. Here again, the energy of interaction varies as (orientation effect). 

Which is more important, the difference in electronegativity between the bonded halogens or the length of the bond between them [Remember that the dipole moment depends on both charge and distance (p. = e X d).]... 

Dipole moments depend on bond polarities. For example, the trend in dipole moments for the hydrogen halides follows the trend in electronegativity differences the more polar the bond (indicated by Ax), the larger the molecular polarity (indicated by the dipole moment, fi ... 

Several physicochemical properties of the bases, outstanding among which is the dipole moment, depend on both the -n- and u-electrons of the molecule. Calculated total charges are indicated on Fig. 4. Those on the nitrogens are in the order N-3 > N-8 > N-l, with the exception of the nonempirical calculations giving the order N-8 > N-l > N-3. Total... 

The induced dipole moment depends on the electric field strength and the structure of the molecule. Charge-induced dipole interactions occur between a charged ion and polarized molecules. A molecule possessing conjugated double bonds is readily polarized. Examples of solutions due to the dipole-induced dipole interaction are benzene in methanol, chloral hydrate in CC14, and phenol in mineral oil. 

Before delving into the Raman spectroscopy of intermolecular modes, it is useful to discuss the IR spectroscopy of these modes briefly. Consider a liquid composed of N molecules, each containing n atoms. The energy of interaction of a liquid with an external electric field E is given by —M E, where M is the collective dipole moment of the liquid. The dipole moment depends on the coordinates of the molecules (qi, q2, - - - fl3nN) in a complicated manner, and these coordinates evolve in time in an equally complicated manner. It is customary to describe the time dependence of... 

The magnitude of a dipole moment depends on both charge and distance between atoms. Fluorine is more electronegative than chlorine, but a C-F bond is shorter than a C-Cl bond. Thus, the dipole moment of CH3F is smaller than that of CH3CI. 

The dipole moment depends on concentration, a property typical of compounds containing the imino group and forming intermolecular hydrogen bonds.163 Imidazole association can thus be explained by... 

The electronic transition dipole moment depends on the nuclear coordinates. Certain transitions are forbidden by symmetry, for example in CO2 and N2O. 

Applications of the Born—Kirkwood-Onsager model at the ab initio level include investigations of solvation effects on sulfamic acid and its zwitterion,23i an examination of the infrared spectra of formamide and formamidic acid,222 and a number of studies focusing on heterocyclic tautomeric equilibria.222,232,233 a more detailed comparison of some of the heterocyclic results is given later. The gas phase dipole moment depends on basis set, and systematic studies of this dependence are available. Furthermore, the effects of basis set choice and level of correlation analysis have been explored in solvation studies as well,222,233 but studies to permit identification of particular trends in their impact on the solvation portion of the calculation are as yet insufficient. 

The molecular-beam method has the further advantage that it can be used in many cases where the other methods cannot be applied. The methods in general use for the determination of dipole moments depend on the measurement of the dielectric constant of the substance in question in the form of vapour or of a dilute solution in a non-polar solvent, usually benzene. Many of the substances which do not dissolve to a sufficient extent in a solvent of this type and which cannot be transformed into vapour with a pressure suitable for the measurement of the dielectric constant can be investigated by means of the molecular-beam method, as the latter merely requires that it should be possible to sublimate the substance in a high vacuum. 

The amount of charge at the interface depends on the field strength and the dielectric properties (conductivity and permittivity) of the particle and the electrolyte. However, there is a slight asymmetry in the charge density on the particle which gives rise to an effective or induced dipole across the particle. Note that if the field is removed the dipole disappears, it is induced . The magnitude of the dipole moment depends on the amount of charge and the size of the particle. For a spherical particle in an electrolyte subject to a uniform applied electric field, three cases can be considered ... 

Polarity is a molecular property. For polyatomic species, the net molecular dipole moment depends upon the magnitudes and relative directions of all the bond dipole moments in the molecule. In addition, lone pairs of electrons may contribute significantly to the overall value of ji. We consider three examples below, using the Pauling electronegativity values of the atoms involved to give an indication of individual bond polarities. This practice is useful but must be treated with caution as it can lead to spurious results, e.g. when the bond multiplicity is not taken into account when assigning a value of x - Experimental values of molecular electric dipole moments are determined by microwave spectroscopy or other spectroscopic methods. 

It is not surprising that, for a number of various reasons (solute-solvent interactions, hydrogen bonding, complex formation, solvent polarity), dipole moments depend on the nature of the solvent. Thus, somewhat different values can be obtained in different solvents, and they are normally different from gas-phase measurements. 

The energy of molecules that contain permanent charges or local dipole moments depends on the interaction of these charges or dipoles with other charges or dipoles in the same molecule or in surrounding molecules. Thus the effects of these electrostatic interactions depend on the conformation of the molecule as well as on the medium. For interactions between ions, the Coulombic potential given by (4) is the dominant terra ... 

The magnitude of the dipole moment depends on the size and symmetry of the molecule. Molecules with a center of symmetry, for example methane, carbon tetrachloride, and benzene are apolar (zero dipole moment) whereas molecules with no center of symmetry are polar. Table 1.2 gives relative static dielectric permittivity... 

Ans. The magnitude of the dipole moment depends chiefly upon the difference in electronegativities. We must therefore calculate these differences using the values in Table 3-4. 

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