Synthesis And Properties Of Nnovel Cyclic Amine+Tetrahedral Organic-inorganic Hybrid Molecules

Organic and inorganic hybrid compounds have attracted more and more attention from researchers due to their advantages such as flexible structure,easy film formation,low cost,and degradability.The organic cationic components in such compounds usually respond to external stimuli,causing structural phase transitions,and accompanying physical,optical,electrical,magnetic,and thermal responses,so these materials can be used as multifunctional materials applied to various fields such as storage,switching,aensing,energy conversion,etc[1-5].This article is mainly divided into three parts.A series of organic-inorganic hybrid compounds were synthesized by using cyclic amine compounds as organic cations and tetrahedral acids(such as HClO4,HBF4,HReO4)as inorganic anions,and the properties of these compounds were studied.The first part mainly studies the synthesis of 1,4,7,10-tetraazacyclododecane and perchloric acid in different molar ratios and obtains their corresponding crystals,and studies their reversible phase transition and ferroelectric properties respectively.The crystals were synthesized using cyclen and perchloric acid in methanol solution at different molar ratio of[C8N4H21(ClO4)](1),[C8N4H22(ClO4)2](2),[C8N4H23(ClO4)3](3),[C8N4H24(ClO4)4](4).Differential scanning calorimetry(DSC),dielectric and second-order nonlinear optical tests revealed that the phase transition temperatures of compound 1,compound 2,and compound 3 were 259 K,309 K,and 352 K,respectively,and compound 4 did not undergo a reversible phase transition.The temperature-change single further confirmed that the phase transition of compound 1,compound 2,and compound 3 was caused by the order-disorder transition of organic amine cation and inorganic acid anion in the compound.The second part mainly introduces 1,4,7,10-tetraazacyclododecane as a macrocyclic compound,and synthesize crystals with perrhenic acid in 1:2,1:3[C8N4H22(ReO4)2](5),[C8N4H23(ReO4)3](6).The phase change properties,dielectric properties and second-order nonlinear optical properties of compounds 5,6 were studied by single crystal diffractometer,differential scanning calorimetry(DSC),dielectric instrument,and second-order nonlinear optics(SHG).By differential scanning calorimetry(DSC)and variable temperature dielectric constant measurement,it was found that the phase transition point of compound 5 was 324 K,and compound 6 did not undergo reversible phase transition and no dielectric abnormality.The third part mainly studies the synthesis of 1,4,7,10-tetraazacyclododecane and tetrafluoroboric acid in 1:1,1:2,1:3 ratios[C8N4H23O(BF4)](7),[C8N4H22(BF4)2](8),[C8N4H23(BF4)3](9).Through single crystal diffractometer,differential scanning calorimetry(DSC),dielectric test,and second-order nonlinear optical test(SHG),it was found that compound 7,compound 8,compound 9 have reversible phase change and dielectric properties.