论文部分内容阅读
分子基磁性材料,可用于信息存储、磁成像、光磁开关等.因此,分子基磁体设计与合成一直是当今科学研究的热门课题.受分子基磁体的启发,本研究合成了新型光调控磁性的分子基磁体含有2-硝基丙烷自由基和2,2,6,6-四甲基-1-氧基哌啶(TEMPO)自由基的联茚满烯二酮衍生物4.化合物4的合成方法为,以光致变色的7,7’-二甲基-3,3’-二乙基-3,3’-二羟基-2,2’-二茚叉基-1,1’-二酮(1)为起始原料,经过溴代反应,得到7,7’-二(溴代甲基)-3,3’-二乙基-3,3’-二羟基-2,2’-二茚叉基-1,1’-二酮(2).化合物2和2-硝基丙烷在乙醇钠的乙醇溶液中反应得到含有2-硝基丙烷自由基和醛基的联茚满烯二酮衍生物3.根据1H NMR,MS和元素分析对化合物3的结构分析表明,2-硝基丙烷基团和化合物3苯环上的亚甲基相连.对化合物3的1H NMR和ESR波谱进一步的分析表明2-硝基丙烷基团上存在单电子自旋.在化合物3的基础上,稳定的氮氧自由基TEMPO被成功地引入光致变色的联茚满烯二酮衍生物的苯环上得化合物4.对化合物2,3和4光照前后的性质变化进行了研究.固态化合物2,3和4光照下皆可发生光致变色;固态化合物2光照后可测得ESR波谱;固态化合物3和4光照前后皆可测得ESR波谱,且光照前后ESR波谱发生变化.磁化率测试表明,固态化合物4光照前后皆具有反铁磁性,且光照后反铁磁相互作用增强.测试结果表明固态化合物3和4光照后有两个或三个自旋中心,分别是2-硝基丙烷或TEMPO自由基以及光照产生的来自于联茚满烯二酮的羰基上的自由基.固态化合物4的颜色和磁性可用光调控.
Molecular-based magnetic materials can be used for information storage, magnetic imaging, magneto-optic switches, etc. Therefore, the design and synthesis of molecular-based magnets has been a hot topic in current scientific research.Inspired by molecular-based magnets, a new type of light- Of a molecular-based magnet contains a 2-nitropropane derivative and a biindane-dione derivative 4 of 2,2,6,6-tetramethyl-1-oxypiperidine (TEMPO) The synthesis method is that photochromic 7,7’-dimethyl-3,3’-diethyl-3,3’-dihydroxy-2,2’-diindenylidene-1,1’- The diketone (1) is used as a starting material to give 7,7’-bis (bromomethyl) -3,3’-diethyl-3,3’-dihydroxy-2,2 ’ -dindenylidene-1,1’-dione (2). Compound 2 and 2-nitropropane were reacted in sodium ethoxide in ethanol to obtain a biindane containing 2-nitropropane radical and aldehyde group Dione derivatives 3. Structural analysis of compound 3 according to 1H NMR, MS and elemental analysis showed that the 2-nitropropane group was linked to the methylene group on the benzene ring of compound 3. The 1H NMR and ESR spectra of compound 3 Further analysis showed that there was a single electron spin on the 2-nitropropane group. On the basis of compound 3, Nitroxide radical TEMPO was successfully introduced into the benzene ring of the photochromic biindane-dione derivative to obtain the compound 4. The changes of the properties before and after the illumination of the compounds 2, 3 and 4 were studied.Solid compound 2, ESR spectra were obtained after illumination of solid compound 2 and ESR spectra both before and after illumination of solid compounds 3 and 4. The magnetic susceptibility tests showed that ESR spectra of solid compounds 2 and 3 were changed before and after light irradiation, The solid-state compounds 4 were both antiferromagnetic before and after light irradiation and the antiferromagnetic interaction was enhanced after light irradiation.The results show that there are two or three spin centers after solid-state compounds 3 and 4, which are 2-nitropropane or TEMPO Free radicals and free radicals generated by light from the carbonyl group of the indanylene dione The color and magnetism of the solid compound 4 can be regulated with light.