P Correlation

In principle it is possible (with a suitably configured spectrometer) to carry out correlation experiments between any pair of NMR-active nuclei. How- 

We mentioned above that it is possible to carry out carbon-carbon correlation experiments using the 2D INADEQUATE procedure. There, as you may remember from the discussion of one-dimensional INADEQUATE, we have a very difficult problem to solve carbon-13 represents only 1.1% of the total carbon nuclei present in a sample. And in the INADEQUATE experiment we need to detect only those molecules containing two carbon nuclei which couple with one another, i.e. about 10 4 of the nuclei present at the same time we have to get rid of the signal coming from those molecules containing only one carbon-13 (the great majority)  

as in the H,H correlation, the actual 2D spectrum forms the central square, and the ID phosphorus spectra are depicted above and to one side of the square. There is a diagonal and there are cross peaks. 

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P correlation of two inorganic hydrated phosphates, (a) bnishite and (b) a bone, are shown [48]. In both cases two phosphorus sites that completely overlap in the 1D MAS spectrum are clearly visible in the 2D spectrum. 

Stone, R., Clarke, A., and Beckwith, P, Correlations for the laminar-burning velocity of methane/diluent/air mixtures obtained in free-fall experiments. Combust. Flame, 114, 546, 1998. 

Wilke, CR Chang, P, Correlation of Diffusion Coefficients in Dilute Solutions, AlChE Journal 1, 264, 1955. 

Palm, K., Luthmann, K., Ungell, A.-L, Strandlund, G., Artursson, P. Correlation of drug absorption with molecule surface properties, f. Pharm. Sci. 1996, 85,... 

Jandera, P., Correlation of retention and selectivity of separation in reversed-phase high-performance liquid chromatography with interaction indices and with lipophilic and polar structural indices, J. Chromatogr. A, 656, 437, 1993. 

As 31P is the only phosphorus isotope, these problems do not arise. Figure 30 shows the result of a 2D P,P correlation carried out for compound 6. 

Taipalensuu, J., Tornblom, H., Lindberg, G., Einarsson, C., Sjoqvist, F., Melhus, H., Garberg, P., Sjostrom, B., Lundgren, B., Artursson, P., Correlation of gene expression of ten efflux proteins of the ATP-binding cassette transporter family in normal human jejunum and in human intestinal epithelial Caco-2 cell monolayers, J. Pharmacol. Exp. Ther. 2001, 299, 164-170. 

P., Correlation of drug absorption with molecular surface properties,... 

H12. Hoogstraten, B., Baker, H., and Reizenstein, P., Correlation between serum folic acid activity and response to antifolate therapy. Blood 17, 787 (1961). 

Vi Dimensionless distance parameter P Correlating parameter, various... 

The Hammett cr—p correlation has proved useful in studying substituent effects of aryl-substituted systems.55 In Section 6.1 we consider applications of this linear free-energy relationship to solvolysis with rearrangement. 

Hammett a-p correlations also point to the influence of polar effects in the abstraction reactions. 

Ionic strength (kHlk0)a kulk15 P Correlation coefficient... 

Log P correlated well for six-carbon aromatics and small alcohols and carboxylic acids (in regard to number of carbons). Correlations for two-carbon alkanes were also better than the other descriptors (see Figure 5.15). 

Amalric, L., Guillard, C., Brude, E., and Pichat, P., Correlation between the photocat-alytic degradability over Ti02 in water of met a- and para-substituted methox-ybenzenes and their electron density, hydrophobicity and polarizability properties, Water Res., 30, 5, 1137, 1996. 

These results are now in terms of correlation functions of P2Ct) and, in the field on cases, of P (t), as in linear dielectric and other response theories. The asymmetry given by the last term of the field on expression reveals the interesting possibility of obtaining both P correlations (from the field off response) and P correlations (from the asymmetry). One easily verifies that Benoit s result is obtained for diffusional reorientations, as then = (l/5)exp(-6D t), -(2/15)exp(-6Dt), and PoP2PlPl(t)> = (2/15)exp(-2D t)7 but this form of dynamics is not assumed in the development End effects of joint correlations Eire included in eqs.13 and 14. 

The solubility data in Table I may be used to test the log P correlations in poly(ethylene-co-vinyl acetate) and polyether-urethanes. The correlations in Equations 19 and 20 are derived by combining this data with the reported (20) water solubilities and octanol-water partition coefficients of the steroids (22-24). 

Table II. Polymers and their Solubility Parameters for which Log P Correlations are being Studied...

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