Deuterium (2H) and Nitrogen 14 (14N) NMR spectroscopy were used to investigate the molecular dynamics in one thermotropic and one lyotropic liquid crystal. Quantitative analyses of deuterium spectral densities of motion for three deuteron sites (ring and C[alpha]) at two different Larmor frequencies (46 and 61.4MHz) are reported in the smectic A and C* phases of (S)-[4-(2-methylbutyl)phenyl]-4’-octylbiphenyl carboxylate (8BEF5-d15), a partially deuterated smectogen. 2H spectral densities for two deuteron sites on the chain (C1 and C2/C3) at Larmor frequency 61.4MHz and 14N spectral densities for the head group (NH4+) of the molecule decylammonium chloride (DACl) at 28.9MHz are reported in the lamellar phase of a partially deuterated sample, DACl-d11/H2O binary system. The motional model is the small step rotational diffusion for reorientations plus internal rotations in the strong collision limit. In the chiral C* phase of the first molecule, 8BEF5-d15, the helical axes are aligned along the external magnetic field and the deuteron spins appear to relax in a macroscopically uniaxial environment. After including the molecular tilt, the reorientation processes in the SmC* phase are found to have higher activation energies than those in the smectic A phase. Applying the same motional models to the lyotropic molecule DACl-d11, the tumbling motion of the long axis of the molecule in the aggregates is more rigorous in comparison to the molecular spinning motion. The similarity of deuterium spectral densities from the C1 and C2/C3 sites may indicate a relatively rigid unit of C1-C2-C3-C4 in the backbone.

Phospholipid liposome binding to hydrogel beads based on poly(N-isopropylacrylamide) (PNIPAM) is accomplished employing either avidin/biotin conjugation or hydrophobic modification of the microgels, and the ability to form single supported lipid bilayers is explored. The co-monomer acrylic acid (AA), evenly distributed or localized to the shell of the microgel, is included to facilitate post-polymerization chemical modification of the hydrogel beads. The degree of chemical modification of the microgels as well as the thermal behavior is monitored via 1H and 13C nuclear magnetic resonance (NMR). Liposomes composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phoshocholine (POPC) and a small amount of commercially available biotinylated-lipid are shown to bind as intact entities while sequestering internal contents to biotinylated hydrogel beads, utilizing avidin as the coupling agent. Under fusogenic conditions, these bound liposomes remain as individual vesicles. Alternatively, POPC liposomes are shown to bind to microgels modified to display single chain alkyl groups or cholesteryl moieties, and remain as intact vesicles. It is demonstrated that these liposomes become permeable at high hydrophobe content. Bound liposomes will fuse into larger structures under high hydrophobe content conditions, but remain permeable. The volume phase transition (VPT) characteristic of PNIPAM microgels is shown to influence the permeability of hydrophobically bound (low hydrophobe content), but not avidin/biotin conjugated, liposomes. The degree of liposome binding, as well as their resulting structures and permeability are investigated utilizing 31P NMR, fluorescence spectroscopy and microscopy. The microgel-bound liposome and microgel-supported lipid bilayer hybrid systems would be ideally suited to drug delivery and tissue engineering applications. The microgel-supported single lipid bilayer system would, in addition, potentially act as a cell model system for membrane dynamics and embedded amphiphile NMR studies.

Quantum information processors have the ability to drastically change our world. By manipulating bits of information ruled by the laws of quantum mechanics, computational devices can perform some computations that are classically intractable. Most quantum algorithms rely on pure qubits as inputs and require entanglement throughout the computation. In this thesis, we explore a model of computation that uses mixed qubits without entanglement known as DQC1 (deterministic quantum computation with one quantum bit), using the physical system of liquid-state Nuclear Magnetic Resonance (NMR). Throughout our research, we experimentally implement an algorithm that completely encapsulates the DQC1 model, and take a close look at the quantum nature of DQC1-states as given by the quantum discord and geometric quantum discord, which are measures of non-classicality that capture correlations weaker than those measured by entanglement. We experimentally detect and quantify these correlations in an NMR DQC1 quantum information processor.

Deuterium (2H) and Nitrogen 14 (14N) NMR spectroscopy were used to investigate the molecular dynamics in one thermotropic and one lyotropic liquid crystal. Quantitative analyses of deuterium spectral densities of motion for three deuteron sites (ring and C[alpha]) at two different Larmor frequencies (46 and 61.4MHz) are reported in the smectic A and C* phases of (S)-[4-(2-methylbutyl)phenyl]-4’-octylbiphenyl carboxylate (8BEF5-d15), a partially deuterated smectogen. 2H spectral densities for two deuteron sites on the chain (C1 and C2/C3) at Larmor frequency 61.4MHz and 14N spectral densities for the head group (NH4+) of the molecule decylammonium chloride (DACl) at 28.9MHz are reported in the lamellar phase of a partially deuterated sample, DACl-d11/H2O binary system. The motional model is the small step rotational diffusion for reorientations plus internal rotations in the strong collision limit. In the chiral C* phase of the first molecule, 8BEF5-d15, the helical axes are aligned along the external magnetic field and the deuteron spins appear to relax in a macroscopically uniaxial environment. After including the molecular tilt, the reorientation processes in the SmC* phase are found to have higher activation energies than those in the smectic A phase. Applying the same motional models to the lyotropic molecule DACl-d11, the tumbling motion of the long axis of the molecule in the aggregates is more rigorous in comparison to the molecular spinning motion. The similarity of deuterium spectral densities from the C1 and C2/C3 sites may indicate a relatively rigid unit of C1-C2-C3-C4 in the backbone.

The research work reported in this thesis deals with the development of novel NMR experimental techniques for the spectroscopic discrimination of enantiomers dissolved in a chiral liquid crystalline medium. The information on the chemical shifts and coupling constants pertaining to each enantiomer has been derived on the investigated chiral molecules. The enantiomeric excess (ee), a parameter which is of profound importance in pharmaceutical industry and in asymmetric synthesis, has also been measured. A special attention is paid to the use of high sensitivity of H NMR for chiral discrimination. Typical analyses of H NMR spectra are severely hindered due to enormous spectral inhomogeneous broadening arising from too many unresolved transitions, in addition to superposition of spectra from both the enantiomers. Therefore, the major part of the work is focused on the design and application of pulse sequences to overcome many of these drawbacks. This helps to achieve very high resolution, discerning of overlapped transitions, identification of resonances pertaining to each enantiomer and simplification of the spectrum for easy extraction of spectral parameters, in addition to the accurate measurement of ee. Initially a brief discussion is provided on enantiomers, diastereomers, basic principles of NMR spectroscopy, the several interaction Hamiltonians responsible for yielding the NMR spectra, introduction to product and polarization operator formalisms that gives insight into the spin dynamics for designing appropriate two-dimensional (2D) NMR experiments. This sets the foundation to understand the complex multiplet structures of the diagonal peaks and cross peaks in the resulting 2D spectrum. Subsequently, a brief introduction is given for the available techniques for NMR spectroscopic discrimination of enantiomers in isotropic medium, where only chemical shifts are employed as a measurable parameter. The limitations of these techniques are circumvented by the introduction of other anisotropic NMR parameters, such as homo-and hetero-nuclear dipolar couplings, quadrupolar couplings and chemical shift anisotropies. To achieve this goal the enantiomers are dissolved in weakly aligning chiral liquid crystalline (CLC) medium. To understand this, a general introduction to liquid crystals and their utility as an alignment medium in NMR spectroscopy and the anisotropic interactions affecting the NMR spectrum has also been provided. The preparation of the CLC phase of Poly-γ-Benzyl-L-Glutamate (PBLG) employed in the present study and its orientational behaviour has been discussed. The detection of NMR spectra of various nuclei and the interaction parameters utilized for chiral discrimination will be enumerated. A brief summary of the experiments employed for the spectral analyses of the enantiomers dissolved in PBLG will also be presented.

Erlangen, Nürnberg, Universiẗat, Diss., 2007. / Enth. 1 Sonderabdr. aus: Pain ; 2007. - Beitr. teilw. dt., teilw. engl.

Würzburg, Universiẗat, Diss., 2007.

Zugl.: Würzburg, University, Diss., 2005.

Zugl.: Stuttgart, Univ., Diss., 2007

Universiẗat, Diss., 2006--Frankfurt (Main). / Zsfassung in dt. und engl. Sprache.