Contour diagrams

Rowell and co-workers [62-64] have developed an electrophoretic fingerprint to uniquely characterize the properties of charged colloidal particles. They present contour diagrams of the electrophoretic mobility as a function of the suspension pH and specific conductance, pX. These fingerprints illustrate anomalies and specific characteristics of the charged colloidal surface. A more sophisticated electroacoustic measurement provides the particle size distribution and potential in a polydisperse suspension. Not limited to dilute suspensions, in this experiment, one characterizes the sonic waves generated by the motion of particles in an alternating electric field. O Brien and co-workers have an excellent review of this technique [65]. 

Fig. 5.1 Variation in the energy of pentane with the two torsion angles indicated and represented as a contour diagram and isometric plot. Only the lowest-energy regions are shown.

These two-dimensional CH shift correlations indicate CH relationships through two and more bonds (predominantly Jch and Jch connectivities) in addition to more or less suppressed Jch relationships which are in any case established from the CH COSY contour diagram. Format and analysis of the CH COLOC or HMBC plots correspond to those of a C//COSY or HSQC experiment, as is shown for a-pinene (1) in Figs. 2.14 - 2.17. 

Many graphics packages allow for contour diagrams and surface plots. These are given above for the square of the LCAO plus combination, for any plane containing the intemuclear axis. 

Fig. 12-7. Potential energy contour diagram showing the course of an aromatic substitution X+ + ArH - ArX + H+ (after Zollinger, 1956 a).

Fig. 6a.—Contour diagram of S1 (square of bond strength of orbital) for s-p-d hybridization.

A crude idea of the real situation can be obtained with the help of the contour diagram in Fig. 2, which was constructed with the assistance of many energies calculated for different points (Rp R2)16). 

Fig. 16. Contour diagram of the 15bu lone pair orbital in trans-Li2[MeGaGaMe] obtained with a 6-310 basis set [40]...

FIGURE 26.7 Newton s interference fringes and the corresponding contour diagrams showing the difference between the contact area of a ruhher sphere and a glass plate when (right) wetted with distilled water and (left) with a polar substance added to the water. (From Roherts, A.D., The Physics of Tire Traction, Theory and Experiment, Hayes, D.L. and Browne, A.L. (eds.). Plenum Press, New York/London, 1974.)... 

Fig. 23. The three-dimensional plot of the product flux contour diagram for the 0(1D) + H2 —> OH + H reaction at the collision energy of 1.3 kcal/mol.

Fig. 7.4 Surface plot of the contour diagram given in Fig. 7.3, illustrating the concept of torsional sensitivity. The numerical values were taken from M. Cao and L. Schafer, J. Mol. Struct., 284 (1993) 235.

Figure 6. The contour diagrams of the highest occupied (bottom) and the lowest unoccupied (top) molecular orbitals for PNA. (Reproduced with permission from Ref 13. Copyright 1979, Phys. RevJ...

Van Duuren [37] examined the use of emission and excitation spectra in the identification of aromatic hyorocarbons. Contour diagrams of fluorescence activity at various excitation and emission wavelengths have been used as a means of identifying petroleum residues. 

Table 3.23 summarizes the rotation barriers and leading vicinal cr-cr interactions for methyl rotors CH3—X(X = CH3, NH2, OH) as well as higher group 14 congeners H3M—MH3(M = Si, Ge). Figure 3.59 shows orbital contour diagrams for syn and anti orientations of selected vicinal donor-acceptor NBOs in these species. We now discuss some qualitative trends of torsion barrier potentials in terms of these examples. 

Figure 3.77 depicts contour diagrams of the leading excited-state TB interactions... 

Figure 3.81 Geminal interactions in cyclopropane and propane, showing bent cyclopropane (a) bond

What is the nature of the multiple metal-metal bonds Let us consider the specific example of HW WH, whose NBO Lewis structure exhibits five metal-metal bonds. Figure 4.24 displays the strongly trans-bent geometry of HW=WH and contour diagrams of the five metal-metal bond NBOs, each drawn in a chosen contour plane (specified in the lower-left-hand corner of the panel) to emphasize its distinguishing characteristics. 

Figure 4.65 shows contour diagrams of the aHH— ifir and nir— oHh interactions at R = 1.8 A, permitting direct comparisons with Fig. 4.62. In this case the metal acceptor nir orbital is of high s character (sd013), and the ami— nir interaction...

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