Absorption 3, single-crystal

Figure 7. Ground-state wave function of plastocyanin. A HOMO wave function contour for plastocyanin (28). B HOMO wave function contour for the thiolate copper complex tet b (34/ C Copper L-edge (38) and sulfur K-edge (34) spectra as probes of metal-ligand covalency. D Absorption, single-crystal polarized absorption, and low-temperature MCD spectra of plastocyanin. The absorption spectrum has been Gaussian resolved into its component bands as in reference 33.

Figure Bl.22.1. Reflection-absorption IR spectra (RAIRS) from palladium flat surfaces in the presence of a 1 X 10 Torr 1 1 NO CO mixture at 200 K. Data are shown here for tluee different surfaces, namely, for Pd (100) (bottom) and Pd(l 11) (middle) single crystals and for palladium particles (about 500 A m diameter) deposited on a 100 A diick Si02 film grown on top of a Mo(l 10) single crystal. These experiments illustrate how RAIRS titration experiments can be used for the identification of specific surface sites in supported catalysts. On Pd(lOO) CO and NO each adsorbs on twofold sites, as indicated by their stretching bands at about 1970 and 1670 cm, respectively. On Pd(l 11), on the other hand, the main IR peaks are seen around 1745 for NO (on-top adsorption) and about 1915 for CO (tlueefold coordination). Using those two spectra as references, the data from the supported Pd system can be analysed to obtain estimates of the relative fractions of (100) and (111) planes exposed in the metal particles [26].

AH intrinsic germanium metal sold is specified to be N-type with a resistivity of at least 40 H-cm at 25°C or 50 H-cm at 20°C. Germanium metal prepared for use in infrared optics is usuaHy specified to be N-type with a resistivity of 4-40 Hem, to be stress-free and fine annealed, and to have certain minimum transmission (or maximum absorption) characteristics in the 3—5 or 8—12 pm wavelength ranges. Either polycrystaHine or single-crystal material is specified. 

The physical properties of tellurium are generally anistropic. This is so for compressibility, thermal expansion, reflectivity, infrared absorption, and electronic transport. Owing to its weak lateral atomic bonds, crystal imperfections readily occur in single crystals as dislocations and point defects. 

To determine of Ce(IV) in acid soluble single crystals, a simple and sensitive method is proposed. The method is based on the reaction of tropeoline 00 oxidation by cerium(IV) in sulfuric acid solution with subsequent measurement of the light absorption decrease of the solution. The influence of the reagent concentration on the analysis precision is studied. The procedure for Ce(IV) determination in ammonium dihydrophosphate doped by cerium is elaborated. The minimal determined concentration of cerium equal to 0.04 p.g/ml is lower than that of analogous methods by a factor of several dozens. The relative standard deviation does not exceed 0.1. 

To increase the radiation absorption and ionization efficiency of IR YAG-Nd laser (wave length - 1064 nm) used in for analysis of synthetic oxide single crystals Bi Ge O, Li MoO, LiB O, the samples were grounded and pills of 010 mm were pressed and analyzed by LIMS EMAL-2 (Uki aine) ... 

One must be sure of the purity of the model compound. It may have deteriorated (for example, by reaction or water absorption), its surface may not have the same composition as the bulk, or it may not be of the correct crystallographic phase. It is tempting to use single crystals to be sure of the geometric structure, but noncubic crystals give angle-dependent spectra. The crystallography of any compound should be checked with XRD. 

Figure 6-6a. b- anil c-polarizcd absorption speclra of single crystal at 4.2 K. O and O" arc two Herzberg-Teller false origins as discussed in the text (Section 6.4.1). The most intense vibrational modes are indicated. 

Tabic 6-3. Vibrational assignment of the b- and c-polarized absorption spectra of T6 single crystal at 4.2 K. The proposed assignment is in agreement with the most intense vibrational modes found by Bimbaum et al. [64] in the excitation spectra of matrix isolated tetralhiophene (T4) at low temperature. 

Figure 6-1V. Comparison of the b- and c-polari/cd single crystal absorpiion spectra at 4.2 K with llie unpolarizcd absorption spectrum of a polycrystallinc thin film at 1.6 K. Note that the a origin is also observed in the film.

In this article we have reviewed the results of a joint spectroscopic and morphological investigation of -sexilhienyl (T(J. The lowest singlet electronic level, which is assigned to I B , splits in the single crystal into four crystalline levels. The structure of the exciton band is investigated by the combined absorption and... 

For the three oclyloxy-subslitulcd five-ring oligomers, the normalized photoluminescence spectra of the single crystals are depicted in Figure 16-26. Due to the large absorption coefficient (more than 105 cm"1 at the maximum) we were not able to measure the absorption spectra of the relatively thick (20-30 pm) single crystals (see Table 16-5 in Section 16.3.3.3.1). 

Fig 2 Absorption spectrum of a single crystal of PETN [Deb, according to Bowden Yoffe (Ref 19)]... 

Fig. 3 Single beam IR transmission spectra of a single-crystal of orthorhombic Sg at two polarizations (hiu parallel to crystal c axis, l 2u+ 3u perpendicular to c) showing the strong absorption of the IR active vibrations V4 and Vg (resolution 2 cm ), after [105]. Sample thickness 450 pm...

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