Near IR spectrum

Visible and near-IR spectra of I are shown in Figures 4 and 5, respectively. Both regions of the spectra are distinctive due to the sharpness and abundance of absorptions. At this time a detailed analysis of the spectrum of I has not been carried out. However, qualitative comparison with some spectra of Pu(IV) compounds does reveal some interesting relationships. 

Important weather details are not only provided by the newest information from the Cassini orbiter the Very Large Telescope in the Atacama desert and the W. M. Keck Observatory on Hawaii are also involved. Near-IR spectra show increased cloudiness in the Titanian troposphere on the morning side, i.e., there are methane clouds at a height of about 30 km and methane drizzle at the surface (Adamkovics et al., 2007). 

Sample purity is documented with SEM, TEM, and electron microprobe elemental analysis. Raman and UV-vis-near-IR spectra are also useful techniques that can be used to examine the quality of CNTs at the different stages of the purification procedure. 

Near-infrared spectroscopy is quickly becoming a preferred technique for the quantitative identification of an active component within a formulated tablet. In addition, the same spectroscopic measurement can be used to determine water content since the combination band of water displays a fairly large absorption band in the near-IR. In one such study [41] the concentration of ceftazidime pentahydrate and water content in physical mixtures has been determined. Due to the ease of sample preparation, near-IR spectra were collected on 20 samples, and subsequent calibration curves were constructed for active ingredient and water content. An interesting aspect of this study was the determination that the calibration samples must be representative of the production process. When calibration curves were constructed from laboratory samples only, significant prediction errors were noted. When, however, calibration curves were constructed from laboratory and production samples, realistic prediction values were determined ( 5%). 

Figure 3. Visible—near IR spectra of high coverage (---------) and low coverage...

Figure 4. Monomeric visible-near IR spectra in DMF (neutral and oxidized...

Near IR spectra—See Electronic absorption spectra New IR spectra, R sphaeroides reaction centers, 207,208f NH-tautomer structure, porphyrins with nonsymmetrical substitutions, 84 NH-tautomerism, porphyrins with nonsymmetrical substitution, 74-93,89-91 Ni(II)-reconstituted hemoglobin—See Nickel-reconstituted heme proteins Nickel isobacteriochlorin... 

Representative UV/Visible and Near IR Spectra of Thianthrene Radical Ions (1+) and Thianthrenediiums ... 

Table 3 Near-IR Spectra and the Location of Conduction Electron on Polysilanes...

Very little work has been reported for near ir spectra of pellets or mulls mosi measurements ---.are made in solution. 

This paper is a more extensive survey of the influence of the metal on the hyperpolarizability of a series of the transition metal tetrakis(cumylphenoxy)-phthalocyanines (MPcCP4). The compounds chosen were those most closely related to PtPcCP4, the compound which showed the largest hyperpolarizibility in the previous study. Specifically, phthalocyanines substituted with the last four members of the first row transition metal series (Co, Ni, Cu, and Zn) and also with the Ni, Pd, Pt triad were prepared and studied. The near IR spectra of these tetrakis(cumylphenoxy)-phthalocyanines are briefly discussed. Speculation on how metal substitution can influence the third order susceptibility of a near centrosymmetric structure, like that of the phthalocyanines, is presented. 

The near IR spectra of the tetrakis(cumylphenoxy)phthalocyanines have not been reported before. The absorption in the Cu complex and one of the absorptions in the Co complex lie close to bands which have been tentatively assigned to trip-multiplet transitions in other phthalocyanines.(14) However, the other absorption bands shown in Table 1 have not been previously reported for phthalocyanines with no peripheral substitution. The small absorption cross sections of these bands in the cumylphenoxy phthalocyanines suggest that they are forbidden transitions. Possible assignments for these bands include a symmetry forbidden electronic transition (like the MLCT transitions in NiPc discussed above) becoming vibronically allowed, d-d transitions on the metal ion, or trip-multiplet transitions. Spectroscopic studies are in progress to provide a more definitive assignment of these absorptions. 

Figure 7. UV-Visible-Near IR spectra of films of poly (COT) (A) and poly(n-butylCOT) (B).

The near-IR spectra of crystalline samples of the two radical dimers [22]2 (R1 =Me, Et R2 = H) were measured <2005JA18159>. The absorptions in the mid-IR region between 650 and 3100 cm-1 are due to molecular vibrations of the dimer. A well-developed, low-lying absorption cutoff was interpreted as corresponding to a valence band to conduction band excitation. The optical energy gap values are qualitatively in agreement with the values predicted by the LMTO band structure calculations. 

Fig. 12a-d. Visible and near-IR spectra of plastocyanin (adapted from Ref. 35) a Absorption spectrum of films at 270 K (solid line) and 35 K (dashed line) lower curves refer to left-hand scale, upper curves to right-hand scale, b Gaussian resolution of the 35 K absorption spectrum, c Circular dichroism spectrum of plastocyanin in pD = 6 deuterated phosphate buffer at 290 K. d Magnetic circular dichroism spectrum of plastocyanin in deuterated phosphate buffer at 290 K... 

Upon addition of catalyst and heat, three changes appear in the near IR spectra. The epoxy band decreases rapidly, the 0-H band increases and the C=0 band at 1.91 shows a large increase (Tables II and III). Table II shows the effects of phthalic anhydride concentration. Using the 1.66 p M band as an internal standard according to the method of Henniker (14), the 1.91 p M carbonyl and the 1.42 p M hydroxyl were compared to the 1.66 p M C-H band. Increasing the concentration of phthalic anhydride causes an increase in the intensity of the carbonyl band which becomes a maximum at a mole ratio of 1.7 to 1. This carbonyl could be due to monoester or diester in the final product. The hydroxyl band at 1.42 p M on the other hand remains fairly constant. 

The high-information density of mid-infrared spectra is well-known. In comparison, the discrimination power of near-infrared spectroscopy is illustrated in (Fig. 3A) for different monosaccharides, for which diffuse reflectance spectra were recorded. (Fig. 3B) shows the near-IR spectra of two pharmaceutical substances. 

Figure 2 Multiplicative scatter corrected near-IR spectra of suspension-layered pellets and individual ingredients diltiazem HC1 (dash-dot trace), non-pareil seeds (dot trace), and suspension-layered pellets containing 80-100% of theoretical potency (solid traces).

Figure 4 Bootstrap standard deviation plot exhibiting the possibility for qualitative identification of polymer film coating endpoint. Dashed line indicates the three-standard deviation limit for spectral similarity. Near-IR spectra from 10 samples obtained at the 16% theoretical applied solids level were used as a training group.

The conventional NIR region lies between 700 and 2500 nm. Near-IR spectra arise from absorption bands resulting from overtones and combinations of fundamental mid-IR (MIR) stretching and bending modes. They have low molar ab-sorptivities with broad, overlapping peaks. The low absorptiv-ities are a primary reason for the usefulness of the method for analysis of intact dosage forms. These absorbances arise from C-H, O-H, and N-H bonds. 

Multivariate statistical techniques are commonly employed in near-IR quantitative and qualitative analysis because these approaches have been proven useful for extracting desired information from near-IR spectra, which often contain up to 1200 wavelengths of observation per spectrum. Principal component analysis/principal component regression (PCA/ PCR) is one such multivariate approach. Descriptions of this... 

Tablets were stored in a hydra tor for 168 hr, with tablets withdrawn at regular intervals. Samples were weighed and spectra collected prior to HPLC analysis. Near-IR spectra of the tablets were collected in the 1100 to 2500 nm region, using the double-reflecting sample apparatus described by Lodder and Hieftje [89]. The spectra were processed by PC A...

Another tissue type—nails—was studied by Sowa et al. both in vivo and ex vivo [93]. Mid-IR (MIR) and near-IR spectra were collected for viable and clipped human nails. Depth... 

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