Bondi s method

In a reversed-phase liquid chromatography system, if the hydrogen-bonding and Coulombic forces are negligible, the retention of molecules depends upon their size, and the presence of n electrons enhances the selectivity. The molecular size, i.e. the van der Waals volume, can be calculated by hand, by Bondi s method,29 or by certain computer programs. 

Because of the lipophilic nature of the biological membrane and the importance of size and charge distribution, the formal charge at position 7 of the 1,2,4-benzothiadiazine 1,1-dioxide systems and two other parameters, Hansch s hydrophobic 1r parameter and the van der Waals volume (as calculated by Bondi s method), are included in a structure-activity rela-... 

Another source of deviations from rigid-lattice behavior lies in disparity of size between the various repeat units or molecules in the system. A first approximation is then supplied by Staverman s contact number statistics [24] which, if need be, can be extended to more sophisticated levels of development [28-30,32]. Here the emphasis is on ratios of coordination numbers, assumed Identical to ratios of molecular surface areas. The latter can be estimated with Bondi s method [25] and, hence, do not present extra parameters. 

Bondi s method. With this approach, the melting density data for polyethene, polypropene and poly-isobutene were fit with an average deviation from experimentally determined values of about 1 % while for polymers containing polar monomer units, including butan-2-yl acetate, poly(ethenebenzene) and poly(l-ethene-2-methylbenzene), the deviation between experiment and Sako-Wu-Prausnitz correlation was between (3.0 and 3.5)... 

Bondy, S.C. (1979). Rapid screening of neurotoxic agents by in vivo means. In Effects of Food and Drugs on the Development and Function of the Nervous System Methods for Predicting Toxicity. Gryder, R.M. and Frankos, VFL, (Eds.) Office of Health Affairs, FDA, Washington, D.C., pp. 133-143. 

Bondi s calculation method is simple. The van der Waals volumes are the sum of the van der Waals volumes of fragments, as given in Table 6.3. The calculated van der Waals volumes are summarized in Table 6.4. However, these volumes are different from those calculated using the MOPAC-BlogP program, even though the correlation is excellent. 

There is very little problem in calculating an acceptable measure of solute size. Simple calculations of either molecular volume or area based on either Bondi s (Bondi, 1964) or McGowan s (Abraham, 1987) methods work almost as well as those derived from molecular mechanics and quantum chemistry (Leo, 1993). When volume in cubic Angstroms is used, V is normally scaled by 0.01 to produce a coefficient comparable to the others in the equation polarity/polarizability. 

In this expression, V is the polymer specific volume, and Vq is the so-called occupied volume of the polymer, which is commonly estimate as 1.3 times the van der Waals volume of the constituent monomers (75). The van der Waals volumes of monomer units are usually estimated using Bondi s group contribution method (16),... 

The molecules must be divided into groups as defined by the UNIFAC method. The segment surface areas and the segment volumes are calculated from Bondi s tables according to... 

Many attempts have been made to improve the UNIFAC-frf model which cannot be listed here. A comprehensive review was given by Fried et al. An innovative method to combine the free-volume contribution within a corrected Flory-Huggins combinatorial entropy and the UNIFAC concept was found by Elbro et al. and improved by Kontogeorgis et al. These authors take into account the free-volume dissimilarity by assuming different van der Waals hard-core volumes (again from Bondi s tables ) for the solvent and the polymer segments... 

If the two repeat units differ in size, they will also show a disparity in number of nearest neighbor contacts, or coordination number. We follow Staverman [24] and account for such differences assuming that ratios of coordination numbers can be identified with ratios of molecular surface areas. The latter can be estimated with Bondi s group increment method [25]. 

The bottleneck of GB calculations is the determination of the effective Born radii (a), since their magnitude depends not only on the intrinsic atomic (Bondi, or atomic) radii of the atom (p), but also on the geometry of the rest of the molecule, which modulates the average distance of the atom to the solvent. Original formulations of the method used Equation (4.19) for the computation of Born s radii, but all current version rely on an approximate formalism, such as that developed by Hawkins et al. [34], where a pairwise approximation to atomic overlap is used to simplify Equation (4.19) see Equations (4.20)-(4.22). Using this approach Born s radii can be computed very fast, which makes the method suitable for MD calculations ... 

Basabe-Desmonts, L. Zimmerman, R. S. Reinhoudt, D. N. Crego-Calama, M., Combinatorial method for surface-confined sensor design and fabrication, In Springer Series on Chemical Sensors and Biosensors Vol. 3 Frontiers in Chemical Sensors Orellana, G. Moreno-Bondi, M.C., (Eds.) Springer, Berlin 2005... 

The following citations recall the historical development of repertoires and of experimental techniques Bondi, A. Heat of sublimation of molecular crystals. A catalog of molecular structure increments, J. Chem. Eng. Data 1963,8,371-381 Jones, A. H. Sublimation pressure data for organic compounds, J. Chem. Eng. Data 1960,5,196-200 Chickos, J. S. Annunziata, R. Ladon, L. H. Hyman, A. S.. Liebman, J. F. Estimating heats of sublimation of hydrocarbons. A semiem-pirical approach, J. Org. Chem. 1986, 51, 4311-4314 Ouvrard, C. Mitchell, J. B. O., Can we predict lattice energy from molecular structure Acta Cryst. 2003, B59, 676-685 Knauth, R Sabbah, R. Thermochemistry of organic compounds. A review on experimental methods and present-day research activities. Bull. Soc. Chim. Fr. 1990,127, 329-346. 

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