Configurational analysis

As with the configurational analysis, the tri-n-butyltin groups are stripped from the polymers for compositional analysis. 

Very recently (51), nonequivalence has been found in a variety of additional monobasic solutes whose configurational analysis was thought earlier to lie outside the scope of the CSA technique. 2-Butanol, for example, when dissolved in benzene saturated with TFAE, shows nonequivalence in both methyl resonances. A variety of other chiral and prochiral compounds such as 2-propanol, methyl 2-propyl sulfide, 2-aminobutane, and 2-methyl-1-butanol show nonequivalence for their enantiotopic methyl groups under these conditions. The magnitudes of nonequivalence in these instances are small (0.02-0.03 ppm) but, as illustrated in Figure 4 for enriched 2-butanol,... 

High magnetic fields and in particular C-NMR spectroscopy allow the analysis of even longer configurational sequences (tetrads up to nonads). This proved to be important in particular for the analysis of polyolefins like polypropylene or cycloolefin copolymers (COC). These polymers are available via transition-metal mediated (Ziegler-Natta, metallocene) insertion polymerizations, and the configurational analysis provides deep insight into the respective polymerization mechanisms as well as into the structure-property relationships. 

Searle, P.A. Jamal, N.M. Lee, G.M. Molinsky, T.F. (1994A) Configurational analysis of new furanosesquiterpenes from Dysidea herbacea. Tetrahedron, 50, 3879-88. 

In other substituted phosphorinanes the HNMR spectra are too complicated for a clear-cut conformational (and configurational) analysis. Even in 1-methylphosphorinane the H atoms of the 1-Me group appear as two multiplets due to coupling with the (a) and (e) H atoms of C-2 and C-6. However, the (a,a), (a,e) and (e,e)4/H-h coupling constants are too similar to allow conformational analysis by H NMR. We shall see later that 13C NMR is an excellent method for solving these problems. 

Dissection of the molecular wave function by a configuration analysis. 

While the three approaches discussed above lead to a quantitative reproduction of the SE of 1, a dissection of the HF wave function suggested by Inagaki and coworkers47 80 provides qualitative arguments for a rationalization of strain and stability of 1. The method is based on a configuration analysis of the HF wave function, PHF according to equation 15 ... 

In Table 10, results of the configuration analysis of HF/6-31G(d) wave functions of several three-membered rings are shown. Data indicate that47 ... 

The PPP configuration analysis technique and the mo ecules-in-molecules/localized configuration interaction (MIM/LCI) method can provide an explanation of the fact that some cyclic sulfur diimides are colorless, while others are not. Thus, while 1,2,5-thiadiazoles 231 and 232 are colorless, naphtho[l,8- /][l 4,2,6]thiadiazine 229 is colored (low intensity absorption at 642 nm). The energy level of the color band appears to be largely determined by frontier orbital interactions. By considering the overlap between the two fragments, (i) the NSN group and (ii) the... 

Borjesson, L. Csoregh, I. Welch, C. J. Synthesis and configurational analysis of 2,9-disubsti-tuted 1-oxaquinolizidines./. Org. Chem. 1995, 60, 2989-2999. 

Fig. 16. Configuration analysis of 4f5d multiplet energy levels for Pr3+ LiYF4.

Fig. 19. ESA spectra with n polarization (E//c) for Pr +iYLF and configuration analysis of Tj levels.

Fig. 20. ESA spectra with a polarization (E Lc) for Pr3+ YLF and configuration analysis of f3 4 levels.

Sweeney, J. C., Smith, S. V., Brown, H. L., Hamel, B. B., and Grossman, E. D., "A Fundamental Approach to the Thermodynamic Configurational Analysis of Process Flowsheets as Applied to a Refinery Unit," Energy Institute Report No. 75-4, Drexel University, Philadelphia, PA, June (1975). 

Configuration analysis of many-electron wave functions 302... 

As an application to the optical materials, we have shown the first-principles calculations of multiplet energy levels and 4f"—4f"-15d transition spectra of RE ions in YLF. The calculated energy levels provide a theoretical extension of the well known Dieke s diagram up to ca. 350,000 cm-1. The origins of the peaks in the spectra were clarified based on the configuration analysis of the explicit many-electron wave functions. 

Fig. 15. Configurational analysis of chiral [ lsO]phosphorothioates by stereospecific phosphorylation.

Fig. 21. Configurational analysis of chiral [ 160, 70, OJphosphates. Cyclization and methylation products of (S)-1,2-propanediol-( R p)-1 -[16 O,170,1 OJphosphate.

Fig, 22. Configurational analysis of chiral [160.170.ll,0]phosphatcs. Configurations of sni- isomers of the methyl cyclic phosphates (lower plane) and their methanolysis products (upper plane) derived from the ( Rp) and (.Sp) isomers of S-1,2-propanediol-1 -[ 160.l70,1K0]pho.sphate. 

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