Supramolecular Order And Dynamics Of Functional Materials Studied By Solid State Nmr

The goal of this thesis was the investigation of the structure, conformation, supramolecular order and molecular dynamics of different classes of functional materials (phthalocyanine, perylene and hexa-peri-hexabenzocoronene derivatives and mixtures of those), all having planar aromatic cores modified with various types of alkyl chains. The planar aromatic systems are known to stack in the solid and the liquid-crystalline state due to p-p interactions forming columnar superstructures with high one-dimensional charge carrier mobility and potential application in photovoltaic devices. The different functionalities attached to the aromatic cores significantly influence the behavior of these systems allowing the experimentalists to modify the structures to fine-tune the desired thermotropic properties or charge carrier mobility. The aim of the presented studies was to understand the interplay between the driving forces causing self-assembly by relating the structural and dynamic information about the investigated systems. The supramolecular organization is investigated by applying 1H solid state NMR recoupling techniques. The results are related with DSC and X-ray scattering data. Detailed information about the site-specific molecular dynamics is gained by recording spinning sideband patterns using 1H-1H and 13C-1H solid state NMR recoupling techniques. The determined dipole-dipole coupling constants are then related with the coupling constants of the respective rigid pairs, thus providing local dynamic order parameters for the respective moieties. The investigations presented reveal that in the crystalline state the preferred arrangement in the columnar stack of discotic molecules modified with alkyl chains is tilted. This leads to characteristic differences in the 1H chemical shifts of otherwise chemically equivalent protons. Introducing branches and increasing the length of the alkyl chains results in lower mesophase transitions and disordered columnar stacks. In the.

This book provides a comprehensive review of the structure and function of organic and metal-organic supramolecular materials, which will be of interest to students and researchers in this field.

Functional materials have great importance due to their many important applications. The characterization of supramolecular architectures which are held together by non-covalent interactions is of most importance to understand their properties. Solid-state NMR methods have recently been proven to be able to unravel such structure-property relations with the help of fast magic-angle spinning and advanced pulse sequences. The aim of the current work is to understand the structure and dynamics of functional supramolecular materials which are potentially important for fuel-cell (proton conducting membrane materials) and solar-cell or plastic-electronic applications (photo-reactive aromatic materials). In particular, hydrogen-bonding networks, local proton mobility, molecular packing arrangements, and local dynamics will be studied by the use of advanced solid-state NMR methods. The first class of materials studied in this work is proton conducting polymers which also form hydrogen-bonding network. Different materials, which are prepared for high 1H conduction by different approaches are studied: PAA-P4VP, PVPA-ABPBI, Tz5Si, and Triazole-functional systems. The materials are examples of the following major groups; - Homopolymers with specific functional groups (Triazole functional polysiloxanes). - Acid-base polymer blends approach (PAA-P4VP, PVPA-ABPBI). - Acid-base copolymer approach (Triazole-PVPA). - Acid doped polymers (Triazole functional polymer doped with H3PO4). Perylenebisimide (PBI) derivatives, a second type of important functional supramolecular materials with potent applications in plastic electronics, were also investigated by means of solid-state NMR. The preparation of conducting nanoscopic fibers based on the self-assembling functional units is an appealing aim as they may be incorporated in molecular electronic devices. In this category, perylene derivatives have attracted great attention due to their high charge carrier mobility. A detailed knowledge.

Physical techniques such as X-ray crystallography, IR spectroscopy and solution-phase NMR spectroscopy have played key roles in the development of supramolecular chemistry. In recent years other spectroscopic techniques have been applied, expanding the range of information obtainable. The most widely used technique is solid-state NMR spectroscopy but techniques such as neutron scattering and NQR spectroscopy can yield significant information. Computational approaches are now becoming powerful complementary methods to experimental techniques and this book reviews the application of these methods to supramolecular systems. The ten chapters provide up-to-date information on the applications of spectroscopic and computational techniques to a wide range of supramolecular systems: Solid State NMR Studies of Host-Guest Materials Infrared Studies of Zeolite Complexes NQR Studies of Inclusion Compounds Neutron Scattering Studies of Zeolite Complexes Solid State NMR Studies of Catalytic Reactions on Molecular Sieves Recent Advances in Computational Studies of Zeolites Theoretical Studies of Cyclodextrins and their Inclusion Complexes Computer Modelling of the Structures of Host-Guest Complexes Computational Studies of Clathrate Hydrates Ab initio Electronic Structure Calculations on Endohedral Complexes of the C60 Cluster. This timely book will prove to be of great value to supramolecular researchers who are familiar with the spectroscopic techniques but who wish to extend their knowledge of the computational methods (and vice versa), to supramolecular researchers working in allied areas whose work would benefit from applying spectroscopic and computational methods, and finally to workers just entering the fascinating area of supramolecular chemistry.

The combination of supramolecular chemistry, inorganic solids, and nanotechnology has already led to significant advances in many areas such as sensing, controlled motion, and delivery. By making possible an unprecedented tunability of the properties of nanomaterials, these techniques open up whole new areas of application for future supramolecular concepts. The Supramolecular Chemistry of Organic–Inorganic Hybrid Materials gathers current knowledge on the subject and provides an overview of the present state and upcoming challenges in this rapidly growing, highly cross- or interdisciplinary research field. The book details how these designed materials can improve existing materials or generate novel functional features such as chemical amplification, cooperative binding and signal enhancement that are difficult or not at all achievable by classical organic supramolecular chemistry. It also discusses issues related to nanofabrication or nanotechnology such as the directed and controlled assembly or disassembly, biomimetic functions and strategies, and the gating and switching of surface functions or morphology.

Describes the supramolecular properties of molecular assemblies that contain a solid phase, offering an integrated approach to measurement and addressibility. * Offers an integrated approach to measurement and addressibility. * Features case studies describing the major devices developed using this technology. * The prospects for the future of interfacial supramolecular assemblies are considered.