Combination Of N-Arylstilbazolium Organic Nonlinear Optical Chromophores With Metal Iodides:Structural Diversities And Nonlinear Optical Properties

Organic-metal iodide hybrid polymers have broad application prospects in the fields of photoelectric conversion,stimuli-responsive materials,ferroelectric materials,and nonlinear optical materials,and have become one of the hot topics in the field of materials science.Particular attention is paid to organic nonlinear optical materials that can be used for optical signal processing and terahertz generation.However,the use of these organic chromophores has a macroscopically larger nonlinear susceptibility x(2)hinging on the parallel noncentrosymmetric(NCS)arrangement of the crystals.Therefore,we are devoted to the study of the controlled arrangement of solid organic molecules by introducing inorganic anionic metal iodine clusters.In particular,iodoargentate clusters have higher polarizability due to the interaction of Ag…Ag and increase the probability of crystals having NCS arrangement.In this paper,on the basis of research and summarization of existed achievements at home and abroad,organic nonlinear optical chromophore ligands containing D-?-A structure were used to self-assemble lead iodide,silver iodide,cuprous iodide,and bismuth iodide,respectively.In the assembly reaction,18 organic-inorganic hybrid crystalline materials were synthesized,four of which had NCS structures and subjected to second-order nonlinear optical performance tests—second harmonic generation(SHG).Among them,compound 11[(CEMAS)2(Ag5I7)]n and compound 14[(CEMAS-2M)(Ag2I3)]n have strong SHG response,especially Compound 14 is 38 times higher than KDP,which is 6.5 times that of AGS.The characteristics of the introduction of different substituents at the two ends of the donor and acceptor group(especially the hydroxyl groups capable of forming hydrogen bonds)as well as the characteristics of reducing the symmetry of the organic ligands and using the iodoargentate of asymmetric units are discussed.The solvothermal method is used to cultivate single crystals,which greatly improves the success rate of constructing hybrid nonlinear optical materials.The crystal structures of the above 18 compounds were determined by X-ray single crystal diffraction analysis.The purity of the crystals was determined by PXRD,and the spectra were characterized by IR,UV-Vis spectra and thermal analysis tests.The solid-state fluorescence and nonlinear optical properties of some compounds were studied.