Copper(Ⅰ) Based Coordination Crystals And Their Stimuli-responsive Structural Isomerization

Stimuli responsive materials process the ability to change their physico-chemical in response to the changes of external environmental conditions(temperature,light,mechanical force,electric field,magnetic field,humidity,pH and VOCs).The existence of this stimulusresponse mechanism to changes in specific conditions has led to a wide range of applications in sensors,lighting displays,artificial muscles and storage materials.These research fields are key technologies in the current development of science and technology,so that the basic research on stimuli responsive materials has aroused strong interest of researchers.Among the materials with this special and interesting mechanism,organic polymers and amorphous organic molecular materials are the types of materials that researchers have mainly developed and studied before.For example,stimuli-responsive polymer materials are used in drug release control,biotechnology and other fields,or stimuli-responsive organic molecular materials are used in chemical sensing,solid-state storage and other fields.Although a large number of related research progress and achievements on stimuli-responsive materials have been obtained,the exact structure of amorphous materials is usually difficult to obtain,making it very difficult to study the stimuli-responsive mechanism of such materials from the aspect of material structure.The basic theory of materials is studied at a deeper level.For crystalline materials,the lattice arrangement is long-range ordered and their crystal structure can be obtained by X-ray diffraction.Therefore,researchers choose to develop crystalline materials with well-defined structures and stimuli-responsive properties to develop stimuli-responsive materials.The stimuli-response mechanism is further studied.Among the crystalline materials with stimuli-responsive properties,copper(Ⅰ)-containing organic-inorganic composite crystalline materials have the structural advantages of high luminescence efficiency,tunable luminescence properties,physicochemical properties,and diverse crystal structures and functions,as well as their own advantages of low toxicity and low cost make it suitable as a research platform for the study of stimuli-responsive luminescent color-changing materials.The stimuli-responsive material provides reliable theoretical guidance.In summary,this thesis aims to study the stimuli-responsive mechanism of stimuliresponsive crystal materials,and synthesized organic-inorganic composite crystal materials with copper-iodine cores and pyridine as ligands with high luminescence efficiency,and used its structural isomers.The advantages of the material and the property matching in the field of white light emission,a simple method was used to synthesize a white light emitting material with high luminous efficiency,and the material was used as the phosphor part of the white LED to initially realize the white light emission of the LED.The high-contrast luminescence color change of the copper-iodine core is an important means,and the in-situ real-time observation of the stimulus-response process is carried out.Mechanism of action of stimulus-responsive isomerization of crystalline materials.The main research contents of this paper are as follows:1.The second chapter of this thesis starts from two crystal materials,the structural isomers[CuI(py)]n and[CuI(py)]4,although these two crystal materials have completely different copper(Ⅰ)-iodine cluster structure,but these two materials have similar maximum excitation wavelengths and fluorescence emission lifetimes,as well as blue emission and yellow emission as complementary colors,so they can be used as white light emitting materials through simple physical mixing and matching Sex is good.Because the yellow light emission source and blue light emission source of this white light material are structural isomers,they can be obtained from the same raw material through different coordination polymerization conditions,so this advantage can be used to control the coordination polymerization conditions.One-pot method for direct synthesis of white light-emitting materials.In addition to this direct synthesis method,we also achieved the preparation of white light emitting materials by chemically converting a part of[CuI(py)]n into[CuI(py)]4.By comparing the white light materials obtained by the three methods,it is found that they all have the same photophysical properties,and the white light materials obtained by different preparation methods have no intrinsic difference in properties.The application has been preliminary explored.2.In the third chapter of this thesis,the first discovery and transformation of copper(Ⅰ)containing crystalline material[CuI(py)]n to its structural isomer[CuI(py)]4 under the influence of multiple external conditions Multiple stimuli-responsive phase transitions were studied,that is,the dynamically stable phase[CuI(py)]n emitting blue fluorescence can be transformed into a thermodynamically stable phase emitting yellow light under the action of heating,grinding,and solvent molecules,respectively.Construct[CuI(py)]4.Based on the high-contrast fluorescence emission changes and the existence of a clear two-phase interface during stimuliresponsive phase transitions,the stimuli-responsive phase transition process on single crystals was observed in situ and real-time using fluorescence microscopy,revealing that the macroscopic mechanism of isomerization is heterogeneous The structural transformation is along the b-axis of crystallography(and the b-axis of crystallography is also the extension direction of the Cu-I double chain of the one-dimensional copper(Ⅰ)-iodine cluster of the complex),which is the extension direction of the one-dimensional crystal.and the microscopic mechanism of this isomerization is the process of dissociation between ligands and clusterscluster isomerization-recombination.The research and exploration of the structure isomerization mechanism has deepened the understanding of copper-containing organicinorganic composite stimuli-responsive materials,expanded new ideas for studying the stimuliresponsive mechanism,and contributed to the design and development of multi-stimuliresponsive applications of such materials.