Bine shift

In Ref. 26, optical transmission spectra of films deposited nsing Cdli in a NH3/NH4/thiourea bath were substantially blue-shifted (to 2.63 eV) from the normal CdS absorption. While no crystal size was given, from the XRD spectrum given in the paper it appears that the crystal size was considerably larger than 10 nm, and therefore the canse of the bine shift is not clear. No snch shift was seen for fdms deposited under similar conditions but using CdCli instead of the iodide. 

Fnrther, if in all para-snbstitnted phenols the CO stretching vibration is mainly localized on these two fnndamental modes, in some ortho- and meta-phenols it appears coupled with the mode corresponding to the fnndamental three of benzene whose displacements resemble a distortion towards a Catherine wheel type of strnctnre. Snch vibration appears to be rather sensitive to the position (i.e. either cis or tram) of the X atom, being almost independent of its natnre. In all tram ortho- and meto-snbstitnted phenols, it is placed at slightly lower wavennmbers and characterized by a consistently larger IR intensity compared to the cis conformers. Consider the following example. For all tram m-XCeHjOH, it is centred at ca 1322 cm (81-83 kmmoC ) and bine shifts to ca 1334 cm (2-7 kmmoG ) for the cis conformer. In tram ortto-snbstitnted forms, it is found at 1316-1317 cm (73-78 kmmoC ), while in the cis forms it is at 1323-1324 cm- (21-28 kmmor ). 

The expression for AEg (eq. 5.4) has often been nsed to calcnlate the size of small semicondnctor particnlates for comparison with sizes measnred by transmission electron microscopy. Expression 5.4 works well for particles of diameter above -50 A (see e.g. Serpone et al., 1995a). The reasonable congmence notwithstanding, there are other plausible explanations for the observed bine shifts in the bandgap. Studies by Serpone and co-workers (1995a, 1995b) contended that the earlier reports of bine-shifted absorption thresholds, taken as evidence for Q-size effects in small Ti02 particles, may in fact be direct (Franck-Condon) electron transitions in an otherwise indirect-gap semiconductor. 

Nature of Conventional and Improper or Bine Shifting Hydrogen Bonding... 

Well-defined flower-like CdS nanostructures have been synthesized by Tai and Guo (2008) under ultrasound and microwave irradiations, simultaneously. Hexagonal nanopyramids and/or nanoplates were obtained depending on different sulfur sources. The synergistic effect of microwave and sonochemistiy has been proposed for the formation of these nanoflowers. They show a large bine-shift npto 100 nm as compared to simple low-dimensional CdS nanostmctnres. This stmctnre induced shift in optical properties, which may find some potential applications in optoelectronics devices, catalysis, and solar cells. 

Raman spectroscopy is extremely useful for characterization of distibines and dibismuthines, since the metal-metal stretching vibrations give rise to intense, easily identifiable peaks. Several thermochromic and nonthermochromic distibines have been examined as both solids and liquids (see Table VI) (7,40,49-51). With the exception of tetramethyldisti-bine, there are only small shifts in ysbsb between solid and liquid. Nor are there systematic differences between thermochromic and nonthermochromic distibines. The observed range of ySbSb appears to be predominantly... 

The oxindole structure (XXIX) of this alkaloid was established by consideration of a combination of spectral evidence. Thus, its mass spectrum confirmed the analytically found molecular formula of C23H30N2O6 bj showing a molecular ion at m/e 430. Further, it exhibited a strong peak at m/e 225 due to the fragment e, two mass units higher than the corresponding ion in the mass spectra of mitraphylline and carapanau-bine which have a C-16, C-17 double bond. Other peaks in the spectrum are also shifted by the appropriate number of mass units expected for... 

Shifting the focus to chemotypes rather than arrays. Figure 9.6b summarizes the overall effectiveness of the six different chemotypes explored over the timeUne of Project A. This plot illustrates the chanotypes that gave consistently better Pareto ranks. For example, the exploration around the chanical classes C and E (colored in yellow and green, respectively) did not deliver and were therefore abandoned early in the project. Chemotype D gave comparatively better compounds but it was also abandoned after the discovery of chanotype A. Conversely, chemotypes A and B (red and bine) were consistently successful in terms of average Pareto ranks it is no surprise that the drug candidate came from chanotype A. 

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