Hydrogen-Bonding Mediated Assembly Of Naphthalene Diimide Derivatives And Properties Study

Supramolecular chemistry is "chemistry beyond the concept of molecular chemistry", in which complex and orderly supramolecular aggregates with special functions were prepared by interactions of non-covalent bonds. Interactions of non-covalent bonds used to prepare supramolecular aggregates include van der Waals force, hydrogen bonding, hydrophilic hydrophobic interaction,π-π stacking interaction, the charge transfer and so on. Supramolecular aggregates have some unique properties which is different from the single molecules. Physical and chemical properties of the aggregates may change with the interactions of different external stimuli, such as temperature, light, PH, reductant-oxidant and so on. As a result, we can adjust and control the structure and function of aggregates by making use of the responsiveness of aggregates to external stimuli.The 1,4,5,8-naphthalenediimides (NDIs) have attracted much attention due to their excellent photoelectric properties.1,4,5,8-Naphthalenediimides are neutral, planar, and have a large conjugated system, a low LUMO energy level, which make it widely used as organic semiconductor materials and luminescent materials. The molecular structures of naphthalene diimide derivatives are easily modified, and are widely used as supramolecular aggregates construct blocks to prepare aggregates with different morphology and function by supermolecule interactions such as hydrogen bonding and π-π stacking interaction. In this paper, we designed and synthesized a new naphthalene diimide derivatives and succeeded in regulating the morphology, structure and luminance of its aggregates by addition of strong reducing agent hydrazine hydrate, which may potentially be used as optical active aggregate material and fluorescence probe for detection of hydrazine.This paper includes three chapters, contents of each chapter are as follows.In chapter 1, we introduced the background and significance of our research work. We introduced the basic properties, synthetic methods, recently related research works of supramolecular chemistry, naphthalene diimide derivatives, azo compounds.In chapter 2, the formation of one-dimensional supramolecular aggregate structure and regulation of its luminance: we designed and synthesized a new naphthalene diimide derivatives and prepared one-dimensional alignment of ribbon structures by multiple noncovalent interactions with diameters of around 300nm and lengths up to tens of micrometers. We observed that the morphology structure of the aggregates changed to ellipsoid particles when we added strong reductant of hydrazine hydrate to it. Interestingly, the ellipsoid particles could emit strong yellow-green fluorescence, which could be observed clearly by the naked eye when exposed to 365nm ultraviolet light. Then we explored the interactions between the naphthalene diimide derivative and hydrazine hydrate as well as the reasons for the great fluorescence enhancement. At last, the naphthalene diimide derivative showed high selectivity and sensitivity to hydrazine hydrate. Therefore, the present system may be potentially useful for detection of hydrazine.In chapter 3, the preparation of chiral aggregates and regulation of chirality:a series of carboxylic acid substituted naphthalene diimide derivatives with similar molecular structure were synthesized and helical supramolecular aggregates were prepared by strong multiple hydrogen bonding and π-π stacking interaction between naphthalene diimide derivatives and melamine based on a process of chiral symmetry breaking. The research work is of great significance for us to understand the relationship between the chiral of aggregates and molecular structure and provide us an important idea to prepare chiral supramolecular aggregates materials.