Case studies anomalous dispersion

Case study optimised anomalous dispersion small unit cell ... 

Case study optimised anomalous dispersion large unit cell cytochrome C4 (Sawyer, Harding, Gould, Papiz and Helliwell as... 

Cocrystallization of chiral molecules with molecules carrying heavy atoms (to exploit anomalous dispersion effects) resnlting in mnlticomponent crystals has proven useful to enable the determination of absolute structure via crystallographic studies, obviating the need to form a heavy atom salt or for chemical derivatization. In a case study, Bhatt and Desiraju demonstrated the ntility of this approach by, for example, forming multicomponent crystals comprising cholesterol and 4-iodophenol. ... 

The value of the relaxation time is based on dielectric constant studies of Oncley (140) at 25 , who showed that the protein underwent anomalous dispersion and conformed nicely to the simple Debye curve, exhibiting a single critical frequency ve — 1.9 X 10 cycles sec"S a low frequency dielectric increment of -f 0.33 g. liter and a high frequency increment of —0.11 g." liter. The data just presented have been discussed by Oncley (141) and by Wyman and Ingalls (241) with the aid of their nomograms. It appears from their analyses that the facts might reasonably well be reconciled with the assumption either of oblate ellipsoids with p = 3 and A = 0.3 — 0.4 or of prolate ellipsoids with p = H and = 0.3 — 0.4. On the assumption of prolate ellipsoids, however, it would be necessary to assume that there was no component of the electric moment parallel to the long axis (axis of revolution). In either case the two dielectric increments correspond to an electric moment of about 500 Debye units (140). 

C = Cl = 2- Studies on PMPS [43] and TPD/polycarbonate [34, 42], however, show that in neither case was the universality of the log-log plots or the anomalous thickness dependence or the equality of ti and 2 observed. Transport in these systems is therefore non-dispersive. Time-(or thickness-) independent mobility has also been demonstrated in other systems [46]. Dispersive transport in terms of the above theory has, however, recently been observed on polysiloxane with pendant carbazole groups [45]. 

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