Explore The Molecular Structure And Investigate The Photoisomerization And Application Of Donor-Acceptor Stenhouse Adducts

Photochromic materials,with their ability to undergo controlled color changes under light stimulation,serve as a foundational material for advancing applications in optical engineering.Photosensitive molecules are the core functional component of photochromic materials.However,traditional photosensitive molecules,such as azobenzene and spiropyran,experience prolonged exposure to intense ultraviolet light during the photoisomerization process,especially at high concentrations.This leads to molecular self-degradation,subsequently reducing their fatigue resistance.Moreover,comparison to visible light and near-infrared light,ultraviolet light not only exhibits limited penetration capability but may also trigger genetic mutations in living organisms.These constraints undoubtedly impede the practical application and progression of traditional photosensitive molecules.Donor-Acceptor Stenhouse Adducts(DASAs),as a novel class of photosensitive molecules,undergo photoisomerization processes efficiently in response to visible light and thermal stimuli,demonstrating reversible transformation between linear and cyclic states.The isomerization of DASAs is both efficient and sensitive,making them significant subjects for research and application in the field of photochromic materials.Various studies have explored the photoisomerization properties of DASAs by modifying their chemical structures.However,DASAs still face photosensitivity limitations attributed to their structural characteristics.For example,cyclic DASAs undergo spontaneous enol-keto tautomerization reactions,leading to the formation of a mixture of cyclic enolate and cyclic keto DASAs.The triene π-bridge conjugation in the DASAs structure results in strong intermolecular π-π stacking interactions,hindering isomerization in the solid state and thus restricting the broader applications of DASAs.To addressing the aforementioned issues lies in understanding the structural characteristics of DASAs for targeted structural modifications.This dissertation focuses on the molecular restructuring of DASAs,exploring novel derivatives with unique photosensitive properties.The findings lay a theoretical and experimental foundation for the development of photochromic materials.The dissertation focus of this dissertation includes the following:1.Introducing crown ethers(15-Crown Ether-5(CE5)and 18-Crown Ether-6(CE6))as the electron donor moieties to obtain novel DASAs derivatives with intramolecular host-guest interactions.These DASAs derivatives can independently switch between three states(linear,cyclic enolate,and cyclic keto).Hindering the spontaneous occurrence of enol-keto tautomerization in cyclic DASAs.Addresses the issue of spontaneous enolketo tautomerization in cyclic DASAs.The potential of DASAs in the fabrication of multi-stimuli-responsive materials has been validated.2.Introducing alkyl chains of varying lengths into the structure of DASAs resulted in derivatives exhibiting a β “solvent-like” effect in the solid state.The relationship between different alkyl chain lengths and the photoisomerization properties of DASAs was systematically investigated,revealing a critical limit to the alkyl chain length.Additionally,precise control over the photochromic properties of DASAs in the solid state was achieved by altering the illumination conditions,ultimately confirming their potential application in the field of storage-integrated optoelectronic devices.3.Introducing a porous framework structure unit into the DASAs structure,a novel DASAs crystalline material with light-responsive capabilities was synthesized applying a “post-modification” strategy.These DASAs crystal derivatives with isomerization properties were thoroughly investigated,and their photoisomerization behavior was utilized to achieve controlled drug release and regulate surface hydrophobicity.4.Constructing various “solvent-like” solid substrates with different microstructures,the dispersion efficiency of DASAs was not only enhanced in various solid matrices but also validated the positive influence of solid matrices on the photoisomerization process of DASAs.Through the investigation of the photoisomerization properties and applications of DASAs in different solid substrates,the broader application potential of DASAs in the solid state was verified.This includes applications such as high-resolution image projection,solid photochromic materials,and the control of the hydrophobichydrophilic nature of materials.In summary,this dissertation expands the structural diversity of DASAs by synthesizing a series of DASAs derivatives with unique properties.Through a systematic study of the photoisomerization properties of these DASAs derivatives,several challenges have been addressed,and their corresponding application potentials have been verified.Furthermore,the construction of “solvent-like” solid matrices has provided a solution for investigating the photosensitive properties of solid-state DASAs,effectively propelling the further development of DASAs.Therefore,this dissertation not only broadens the structural diversity of DASAs but also establishes a foundation for their applications in fields intersecting with optics.