('13)C and ('15)N NMR chemical shift and spin-lattice relaxation data have been discussed for isomeric 2,4-pentanediamine and 1,3,5-triaminocyclohexane in chapter 1. At high pH, relaxation is consistent with hindered rotation of the NH(,2) group due in part to the formation of intramolecular hydrogen bonds. At low pH, relaxation is consistent with relatively unhindered rotation of the NH(,3)('+) group. Rotational jump rates and barriers are reported, as determined from the NT(,1) ratios between ('15)N and ('13)C nuclei. / Using Forrest's modified equation and proton coupling constants, the conformations of the two isomeric TACH were analyzed. The six-membered ring of the cis-trans isomer is flattened by 1,3 diaxial interactions between two amino substituents; in the cic-cis isomer the ring is puckered due to the non-bonded interaction between the equatorial amino groups and adjacent methylene protons. / The heteronuclear 2D NOE (HOESY) experiment was proposed in chapter 2, and proved to be a powerful technique for structural elucidation and conformation analysis for both ('13)C and ('31)P. It should be noted that this experiment gives information through space (dipolar interaction) rather than through bonds (J-coupling). For carbon-13, HOESY experiment provides information about dipolar interactions between quaternary carbons and nearby protons. A disadvantage of the HOESY experiment is that in order to detect the cross peaks of quaternary carbons a concentrated or isotopically enriched sample must be used. For phosphorus-31, a HOESY experiment was proposed to study solvent and intramolecular proton dipolar relaxation for the three phosphates in ATP. This technique should prove useful for the study of molecular conformation and solvent-solute interactions in a variety of chemical and biological systems. Since the other interesting nuclei can also be observed, the HOESY experiment is expected to have significant potential in studies of peptides (('15)N, ('13)C), metalloenzymes (M), and metabolic studies (('13)P, ('13)C). / Source: Dissertation Abstracts International, Volume: 45-06, Section: B, page: 1770. / Thesis (Ph.D.)--The Florida State University, 1984.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_75349 |
| Contributors | YU, CHIN., Florida State University |
| Source Sets | Florida State University |
| Detected Language | English |
| Type | Text |
| Format | 137 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
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