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.

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.

Supramolecular materials have a great number of applications due to the reversibility of their non-covalent molecular interactions, such as reversible hydrogen bonding, host–guest interactions and electrostatic interactions. This book provides a comprehensive source of information on the structure and function of organic and metal–organic supramolecular materials. The chapters of this book provide an overview of supramolecular material assembly at various scales, including the formation of 2D polymers and molecular cages. The role of intermolecular interactions in solid and solution state self-assembly is discussed, as is the role of mechanochemistry on molecular and supramolecular architectures. Finally, novel applications of these materials in molecular recognition, catalysis, light harvesting and environmental remediation are covered. Functional Supramolecular Materials will be of interest to graduate students and researchers in academia and industry in the fields of supramolecular chemistry and functional materials science.

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.

A one-stop, comprehensive, and thoroughly updated resource for students, professors, and researchers alike Thoroughly revised and updated, the Third Edition of Supramolecular Chemistry delivers a comprehensive and integrated approach to this rapidly evolving and quickly expanding field. Distinguished professors and authors Jonathan Steed and Jerry Atwood provide readers with a broad and exhaustive resource that assumes little in the way of prior knowledge of supramolecular chemistry. Extensive new content on cutting edge research throughout the field including molecular machines and the mechanical bond, mechanochemistry, halogen bonding, and crystal nucleation accompanies full-color imagery and study problems designed to help students understand and apply the principles introduced within the book. Additional material is provided in the supplementary online resources, including solutions to the student exercises and PowerPoint slides of the figures in the book. Supramolecular Chemistry, Third Edition also includes: The latest research and developments reported over the last decade A unique “key references” system that highlights crucial reviews and primary literature A description of key experimental techniques included in accessible “boxes” for the non-expert Exercises and problems for students, complete with online solutions Full-color illustrations and imagery designed to facilitate learning and retention of the key concepts and state-of-the art of the field Perfect for undergraduate and postgraduate students taking courses on supramolecular chemistry, the Third Edition of Supramolecular Chemistry also belongs on the bookshelves of all researchers in this, and any closely related, fields. Academics, in particular postdoctoral students and professors, will benefit significantly from this text.

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.