Donor parameter

It is defined as 1 for ionic groups and 0 for nonionic groups. no A charge transfer donor parameter which takes the values 1 when the sub-... 

Explosive Stimulus Transfer. Under a program to develop a technique to compute probability of detonation transfer between a donor and an acceptor, experiments were performed to measure the effects of seven variables. These included two donor parameters fragment slack energy and five acceptor parameters confinement, closure thickness, explosive material, explosive particle size and closure material... 

Figure 11.5 (a) Van der Waals parameter vdWsurf and (b) H-donor parameter HDsurf of various mineral surfaces as a function of relative humidity (RH) at 15 to 20°C. On the righthand side, the corresponding values of the bulk water surface are indicated. Note that HDsnrf of water is set equal to 1.0, and all other HDsnrf values are determined relative to the water surface. Adapted from Goss and Schwar-zenbach (1999b and 2002). 

Ghafourian, T. and J. C. Dearden. 2004. The use of molecular electrostatic potentials as hydrogen-bonding-donor parameters for QSAR studidsarmaco59 473-479. 

Ea and Ca are empirical acceptor parameters and Eb and Cb are empirical donor parameters. The E parameters are measures of the tendency of an acid or a base to participate in electrostatic interactions, while the C parameters are measures of their tendency to form covalent bonds. 

An alternative approach uses the polarity index, P proposed by Snyder. This is based upon experimentally determined gas chromatographic retention of three test solvents on a large number of stationary phases. The test solvents selected are ethanol, 1,4-dioxane and nitromethane. As well as an overall polarity index (P), three other parameters are calculated, Xe (a proton acceptor parameter), xproton donor parameter) and x (a strong dipole parameter). 

Table 3 lists the Hildebrand solubility parameter 8, the total solubility parameter do, and the multicomponent parameters for dispersion dj, polar dp, and hydrogen bonding d/, forces for a number of solvents. These data are taken from the compilation by Barton (1975). He has pointed out that the data become empirical when multicomponent parameters are used, and thus it is important to use a set of data that are self-consistent. Keller et al. (1971) and Karger et al. (1976) have further subdivided the hydrogen bonding parameter into the acid or proton donor ( ) parameter, and the base or proton acceptor (6/,) parameter. Values for these are listed for some of the compounds in Table 3 from data provided by Snyder (1978). These data are not from the same source as those compiled by Barton (1975) and included in Table 3, and hence the values given for d/, should not be compared directly with those for 8 and 8. ... 

Surface characteristics of the series of commercially available aluminas with the use of IGC were reported by Papirer et al. [34]. Values of the dispersive component of surface free energy 7 varied from 65 to 100 mJ/m. Authors determined also Kd and Ka values. The variation of the electron donor parameter Kd was almost negligible (2.1-2.7), while Ka parameter increased from 5.6 to 9.9 units. The significant changes for acidity were related to the Si02 content. Acidity parameter, Ka, reached a constant value for a Si02 content of about 1000 ppm. However, AN and DN were taken from Gutmann s proposal... 

Fig. 10. 13 Photocurrent action spectra for a monolayer of 3,3 -distearyloxa-carbcyanine on Sn02, in 0.1 M KCl and 10 M allylthiourea as an electron donor Parameters give the concentration ratios of the dye arachidic acid.

Table 5.3. Anisotropy parameters and EMT donor parameters for group IV crystals. The calculated values of the 3p i — 2p i spacings are in units of R ood. The values of es in parentheses are derived self-consistently from the calculations. For diamond, the experimental value of es in brackets is used to determine 7...

In the theory of van Oss a similar expression (equation (7)) can be used and electron acceptor and donor (ys and ys ) values for the surface are obtained, if the electron acceptor and donor parameters (yL and yt ) of the probe molecule are known. 

---