This chapter contains sections titled: Introduction Spectra of Ethylene and its Simple Derivatives Multiply Substituted Ethylenes Compounds with More Than One Double Bond Special Effects Applications to Complex Systems References

We present a new application of nuclear magnetic resonance to monitor rouleaux formation in static blood suspensions of physiological hematocrit. The method measures the apparent mean residence time of water inside the rouleaux and yields the kinetics and the extent of red cell aggregation in units of cells per aggregate.

A new model for water transport in erythrocyte suspensions with explicit consideration of rouleau formation has been developed which accounts for the dependence of the observed mean residence time of water on aggregate size. This formulation also predicts that the mean residence times obtained for aggregates will depend on the concentration of manganese ion in the suspending medium. In addition, analytical solutions of the commonly used two-site exchange equations which relate the mean residence time, the extracellular relaxation time, and the intracellular fraction of water to the double-exponential relaxation parameters are presented.

AbstractThe application of NMR spectroscopy in oriented media to the determination of molecular geometries is illustrated by results for three distinctly different molecules: naphthalene, ethylene oxide and spiropentane. The need for systematic application of vibrational corrections is emphasized and some of the effects associated with the different choices of solvent media are considered.

The proton nuclear magnetic resonance spectra, including 13C satellites at natural abundance, of propargyl chloride partially oriented in a nematic phase were analyzed. The direct coupling constants obtained were corrected for harmonic vibrations and used to calculate geometrical and orientational information. A variation in the temperature at which the NMR spectra were recorded had a negligible effect upon the structure. The difference between the vibrationally uncorrected and corrected distance ratios is substantial.

The NMR spectra for four ortho- and meta-halosubstituted fluorobenzenes oriented in a lyotropic mesophase have been recorded and analyzed. The direct coupling constants obtained were corrected for harmonic vibrations and used to calculate proton and fluorine distance ratios and order tensors. Results are compared to those of other halobenzenes oriented in the same lyotropic mesophase.

AbstractThe calculated 12C, 13C and 77Se spectra of selenophene have been reproduced from the observed proton NMR spectrum in the orienting medium Merck ZLI 1167, and the entire ring structure computed. The effects on structure of vibration, solvent dependence of couplings and temperature have been explored. Most notable was the observation of a substantial increase in the SeC bond length, comparable to that previously reported for selenophene in Merck Phase IV.

The response of human red blood cells to the cryoprotective agents, DMSO and glycerol, has been investigated using a pulsed NMR method. The experimentally determined parameters are: (1) the intracellular transverse relaxation time, T2a; (2) the mean residence time of intracellular water, tau a, which is effectively a reciprocal measure of the rate of water transport across the red blood cell membrane; and (3) the activation energy for this process. The quantitative data indicate that the observed effects are colligative rather than species-specific in origin.

AbstractThe proton nuclear magnetic resonance spectra of benzo[b]‐furan, ‐thiophene and ‐selenophene oriented in a potassium laurate lyotropic liquid crystal have been analyzed. Geometrical information has been obtained and compared to previous thermotropic results and various hypothetical models.

Summary Pulsed nuclear magnetic resonance spectroscopy is employed to determine the time dependence of the change in erythrocyte water permeability following exposure top-chloromercuribenzoate (PCMB) orp-chloromercuribenzene sulfonic acid (PCMBS). pH variation was used to examine the environment of the sulfhydryl groups reactive to these drugs. PCMB reacted with at least two sulfhydryl groups which affect water permeability. This was shown by the double exponential character of the change in erythrocyte diffusional permeability with time after PCMB addition. However, only one inhibition rate process could be distinguished following PCMBS exposure, suggesting that one site bound by PCMB is not accessible to PCMBS. This site is postulated to be located in a hydrophobic region of the membrane, whereas the site reached by both drugs is located in the normal anion permeation channel. The effect of pH on the degree of inhibition due to each component and the inhibition rates is explained in terms of its effect on solubility of the reagents in the membrane and variation of the dissociated-to-undissociated ratio of PCMB.

The NMR spectrum of ethylene oxide has been analyzed for carbon-13 satellites in the liquid crystal, Merck ZLI 1167. Structures derived from vibrationally corrected direct couplings indicate good agreement with gas-phase results. Application of vibrational corrections to previous couplings gives structural parameters suggesting significant distortions from above studies.

The previously reported structures of the difluorobenzenes obtained from partially oriented NMR spectra have been corrected for harmonic vibrational motions. Possible effects arising from pseudo-dipolar couplings have also been investigated. The vibrationally corrected structures are frequently outside of the experimental errors of the uncorrected structures. The vibrational corrections are found to decrease the range in the distance ratios resulting from the use of various solvent systems.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNuclear magnetic resonance of oriented fluorobenzene in a nematic potassium laurate mesophase. Distance ratios and order tensor elementsR. C. Long Jr., E. E. Babcock, and J. H. GoldsteinCite this: J. Phys. Chem. 1981, 85, 9, 1165–1170Publication Date (Print):April 1, 1981Publication History Published online1 May 2002Published inissue 1 April 1981https://pubs.acs.org/doi/10.1021/j150609a018https://doi.org/10.1021/j150609a018research-articleACS PublicationsRequest reuse permissionsArticle Views38Altmetric-Citations7LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access options Get e-Alerts

The hydrogen magnetic resonance spectrum of naphthalene has been obtained in an orienting lyotropic liquid crystal solvent based on potassium laurate, and the results of the spectral analysis were used to calculate the proton geometry of the molecule. Vibrational corrections based on a full normal coordinate treatment have been applied to the structure and the effect of different weighting schemes has been investigated. The results are compared with those obtained in thermotropic media and by other structural methods.

Proton distance ratios and elements of the order tensor are obtained from nuclear magnetic resonance spectra of chloro-, bromo-, and iodobenzene partially oriented in a potassium laurate lyotropic mesophase. Corrections for harmonic vibrations are applied and it is shown that even for proton distance ratios these corrections are significant. Furthermore, the effects of solvent on the ratios determined are comparable to the effect of the substituent. Particular attention to weighting of the dipolar coupling in the structural analysis is necessary if values are to be judged significant to 1 part in 104. The elements of the order tensor are discussed in terms of the orienting influence of the interface and alkyl chains of the mesophase surfactant.

Proton distance ratios and elements of the order tensor are obtained in this study from the nuclear magnetic resonance spectra of 6 para-substituted phenols and 4 monosubstituted benzenes partially oriented in a potassium laurate lyotropic mesophase. Comparison of the structural parameters of aniline and benzonitrile with complete microwave substitution structures shows that the distance ratios are in agreement within 0.7%. The effect of the substituent on ring proton geometry is small. The orientational probability functions are derived and discussed in terms of the orienting influence of the interface and the molecular order of the alkyl chains of the mesophase surfactant. The most probable orientation of the long-axis of the surfactant and the C2v axis coincide for the entire group of molecules. The effect of ionization of the phenolic group is a critical parameter influencing the order elements. Furthermore, those substituents with hydrogens capable of hydrogen bonding are more ordered.

A simple, precise, and rapid pulse nuclear magnetic resonance technique for measuring the rate of water exchange across the erythrocyte membrane is presented. The technique is based upon the nonlinear fit of Carr-Purcell-Meiboom-Gill (CPMG) transverse relaxation time data of blood doped with 1.7 mM MnCl2 to the general two-compartment exchange condition. Previous approaches using CPMG data required high MnCl2 concentrations (25-53 nM), shown in this work to induce systematic errors ranging from 35 to 45%. At 23 degrees C the average residence time of a water molecule inside the erythrocyte (tau a) is 21.0 +/- 0.6 ms (SE). The Arrhenius plot for water exchange is linear over the range of 3 degrees - 37 degrees C and th Arrhenius activation energy is 4.79 +/- 0.03 kcal (SE). This value does not differ significantly from the energy required for bulk water flow. Results are compared with previous determinations, and sources of systematic error in tau a and the activation energy are evaluated.

Proton NMR spectra have been obtained for the p-halofluorobenzenes, p-nitrofluorobenzene, and p-fluoroaniline dissolved in the lyotropic liquid crystal derived from potassium laurate. The spectra in all cases, with the exception of p-fluoroaniline, were not deceptively simple. Structural and orientational calculations have been performed and all parameters are reported here. The motional constants for the p-halofluorobenzenes show an increase in order along the C2 axis as one moves through the series from Cl to Br to I.

Interfacing NMR spectrometers through a Fabritek 1074 computer to a DECsystem-10 computer has been economically accomplished using an SDK-80 microcomputer. Features of the system include minimal hardware design; ease of operation; the use of LED program state indicators and the elimination of a conventional terminal; and the use of structured programming and prior programming specifications. The system has now been extensively used for several months with no problems.

High resolution nuclear magnetic resonance spectra have been obtained for seven p-subetituted pyridine derivatives oriented in lyotropic mesophases derived from sodium decyl sulfate and potassium laurate. Spectral analyses yielded indirect as well as direct coupling information for the ring protons of the pyridine system. The structural parameters determined for all molecules show good agreement with microwave data for pyridine. Orientational changes throughout the series are attributed to solute-solvent interactions.