Structure And Dielectric Properties Of Crown Ether-based Host-Guest Inclusion Compounds

Switchable materials have attracted increasing attention owing to their physical characteristics can be reversibly changed between high and low states under external stimulation,such as light,electricity,temperature,pressure and so on.As far as we known,in various types of phase transition materials,host-guest inclusion compounds are a kind of promising phase transition material.This is due to the fact that supramolecular packing in the host-guest inclusion system provide the results of various motions of host molecules,guest cations and anions,which can induce an order-disorder type phase transition triggered by the external temperature.This paper is devoted to obtaining crown ether compounds with multiple switch response characteristics through structural control,13 kinds of host-guest macrocyclic crown ether compounds(including cyclic amines and chain amines)were designed and synthesized.Crystal structures,dielectric and optical properties of those compounds were also characterized.The research content of this paper is mainly divided into three parts:Part ?:18-crown-6 as the main molecule,perchloric acid as the anion,respectively reacted with the orthotopic(o-),interpositional(m-)and para(p-)chloro-substituted benzylamine guest cation,synthesized 3 compounds,[(o-ClC7H8N)(18-crown-6)][HClO4](1)?[(m-ClC7H8N)(18-crown-6)][HClO4](2)?[(p-ClC7H8N)(18-crown-6)][HClO4](3)and their properties were studied.Part ?:18-crown-6 as the main molecule,benzylamine series substituted by counterpoint as the guest cation,synthesized 5 compounds,[(C7H8BrN)(18-crown-6)][HClO4](4)?[(C8H11N)(18-crown-6)][HClO4](5)?[(C7H8FN)(18-crown-6)][HClO4](6)?[(C7H8FN)(18-crown-6)][HPF6](7)?[(C8H10ClN)(18-crown-6)][HPF6](8),and their properties were studied.Part ?:18-crown-6 as the main molecule,halogenated chain amines as the guest cation,react with inorganic acids respectively,synthesized 5 compounds,[(C2H7NCl)(18-crown-6)][HClO4](9)?[(C2H7NCl)(18-crown-6)][HReO4](10)?[(C2H7NCl)(18-crown-6)][HBF4](11)?[(C2H7NF)(18-crown-6)][HClO4](12)?[(C2H7NBr)(18-crown-6)][HClO4](13),and their properties were studied.Among the 13 compounds,by replacing the guest cation or inorganic anions,four phase change compounds 3,6,9,10 were synthesized.Among them,compounds 3 and 6 are different from previously reported crown ether inclusions.They both have optical multiple bistable response characteristics,which both have NLO and photoluminescence bistable switching response characteristics.The transition of dielectric response from relaxation to switch is also realized.Compounds 9 and 10 have both high and low temperature dielectric properties,and have dielectric relaxation properties.