节点文献
基于萘酰亚胺衍生物聚乳酸的室温磷光研究
Study on Room Temperature Phosphorescence of Polylactide Based on Naphthalimide Derivatives
【作者】 李志伟；
【导师】 张兴元；
【作者基本信息】 中国科学技术大学 ， 高分子化学与物理， 2020， 硕士
【摘要】 室温磷光(RTP)材料因其长寿命的三重态激子和更大的Stokes位移,在传感、成像、显示和数据加密等方面有着广泛的应用。目前主要用于磷光材料的无机和有机金属配合物具有成本高、资源有限和毒性高的缺点,从而催生了相对环境友好且易于改性的无金属有机RTP材料。高分子材料因其出色的柔韧性、易加工和良好的热稳定性比小分子更有实用价值,而且其独特的刚性基质可以限制分子的振动和旋转以及热衰变途径。将发光单元以化学反应的方式接入到高分子中,得到的聚合物材料兼具光致发光和加工性能的特点,因此,高分子RTP材料是低分子量有机RTP化合物的理想替代品。1.通过分子设计并且完成了 4种萘二甲酰亚胺衍生物和3种萘四甲酸二酰亚胺(NTCDI)衍生物的合成:2-丁基-6-(2-羟基乙氧基)-1H苯并[异]喹啉-1,3(2H)-二酮(NI-OH)、2-丁基-6-((2-羟乙基)硫基)-1H-苯并[异]喹啉-1,3(2H)-二酮(NI-SH)、2-(9-乙基-9H-咔唑-3-基)-6-(2-羟基乙氧基)-1H-苯并[异]喹啉-1,3(2H-)-二酮(CZ-NI-OH)、2-(9-乙基-9H-咔唑-3-基)-6-((2-羟乙基)硫基)-1H-苯并[异]喹啉-1,3(2H)-二酮(CZ-NI-SH)、双-N,N’-(2-羟乙基)-1,4,5,8-萘四甲酸二酰亚胺(NEG)、2,7-双(4-(2-羟基乙氧基)苯基)苯并[lmn][3,8]菲咯啉-1,3,6,8(2H,7H)-四酮(NBOH)和2,7-双(4-((2-羟乙基)硫代)苯基)苯并[lmn][3,8]菲咯啉-1,3,6,8(2H,7H)-四酮(NBSH)。分子结构的准确性通过核磁共振氢谱验证;使用电化学手段来比较这些小分子的给电子能力。其中分子CZ-NI-OH、CZ-NI-SH和分子NBOH、NBSH是具有分子内电荷转移态(ICT)的。2.用 NI-OH、NI-SH、CZ-NI-OH 和 CZ-NI-SH 分别引发 D,L-丙交酯聚合,合成了一系列具有光致发光性能的PLA材料:NI-O-PLA、NI-S-PLA、CZ-NI-O-PLA和CZ-NI-S-PLA。其中NI-O-PLA和NI-S-PLA是以荧光发射为主,作为对比,具有给体-受体结构的CZ-NI-O-PLA和CZ-NI-S-PLA则是以室温磷光发射为主,CZ-NI-O-PLA的磷光发射寿命长(τ=407 ms),CZ-NI-S-PLA的红色磷光发射更亮,寿命为54.3 ms。同时我们发现O和S会对这个体系的磷光发射产生不同的影响。3.双羟基发色团NEG、NBOH和NBSH分别接入到L-PLA中,得到NEG-PLA、NBO-PLA、NBS-PLA。NEG-PLA是双发射材料,以蓝绿色荧光发射为主,而NBO-PLA和NBS-PLA的荧光发射很弱甚至肉眼不可见,在真空中会出现红色磷光发射,寿命都在30 ms左右,比常规的纯有机RTP的磷光寿命(<10ms)稍长,新的红色磷光单元被制备;通过改变不同的取代基团,可以实现这类发光材料的荧光/磷光发射比的调节,磷光发射占比从NEG-PLA中的0.95:0.05提升到 0.20:0.80(NBO-PLA)再到 0.12:0.88(NBS-PLA)。定性的比较了 D,L-PLA 和L-PLA对RTP发射的影响,D,L-PLA的RTP发射亮度更亮,而L-PLA的发射波长相对更长。
【Abstract】 Room temperature phosphorescence(RTP)materials are characterized by their long-lived triple excitons and larger Stokes shift,and are widely used in sensing,imag-ing,display,data encryption,and so forth.The inorganic and organometallic complexes currently mainly used in phosphorescent materials have the disadvantages of high cost,limited resources and high toxicity,thus spawning relatively environmentally friendly and easily modif-ied metal-free organic RTP materials.Polymer materials have more application value than small molecules because of their excellent flexibility,easy pro-cessing,and high thermal stability,and the unique rigid matrix can limit the vibration and rotation of molecules and thermal decay pathways.The chromophore is chemically connected to the polymer,and the resulting polymer material has the advantages of photoluminescence and processing performance.Therefore,the polymer RTP material is an ideal substitute for low molecular weight organic RTP compounds.1.The molecules of 4 naphthalimide derivatives and 3 naphthalene tetracarb oxylic diimide(NTCDI)derivatives were designed and synthesized:2-butyl-6-(2-hy droxyethoxy)-1H-benzo[de]isoquinoline-1,3(2H)-dione(NI-OH),2-butyl-6-((2-hydro xyethyl)thio)-1H-benzo[de]isoquinoline-1,3(2H)-dione(NI-SH),2-(9-ethyl-9H-carbaz ol-3-yl)-6-(2-hydroxyethoxy)-1Hbenzo[de]isoquinoline-1,3(2H)-dione(CZ-NI-OH),2-(9-ethyl-9H-carbazol-3-yl)-6-((2-hydroxyethyl)thio)-1H-benzo[de]isoquino-line-1,3(2 H)-dione(CZ-NI-SH),2,7-bis(2-hydroxyethyl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone(NEG),2,7-bis(4-(2-hydroxyethoxy)phenyl)benzo[lmn][3,8]phenan throline-1,3,6,8(2H,7H)-tetraone(NBOH)and 2,7-bis(4-((2-hydroxyethyl)t-hio)phen yl)benzo[lmn][3,8]phenanthroline-1,3,6,8(2H,7H)-tetraone(NBSH).The nuclear ma gnetic resonance(NMR)spectra were used to verify the correctness of these struc tures.Electrochemical methods were used to compare the electron donating ability of these small molecules.Among them,the molecules of CZ-NI-OH,CZ-NI-SH and NBOH and NBSH have intramolecular charge transfer state.2.NI-OH,NI-SH,CZ-NI-OH and CZ-NI-SH were used to initiate the polymeri-zation of D-L-lactide,respectively,and a series of PLA materials with photolumines-cence properties were synthesized:NI-O-PLA,NI-S-PLA,CZ-NI-O-PLA and CZ-NI-S-PLA.Among them,NI-O-PLA and NI-S-PLA are mainly fluorescence emission.By contrast,CZ-NI-O-PLA and CZ-NI-S-PLA with donor-acceptor structure are mainly phosphorescent emission at room temperature.CZ-NI-O-PLA has a long-lived phos-phorescence emission lifetime(maximum lifetime τ=407ms),and CZ-NI-S-PLA has a brighter red phosphorescence emission with a lifetime of 54.3ms.we also found that O and S will have different effects on the phosphorescence emission of this system.3.The dihydroxy chromophores NEG,NBOH and NBSH are connected to the L-polylactide chain,respectively,to obtain NEG-PLA,NBO-PLA and NBS-PLA.NEG-PLA is a dual-emission material,mainly blue-green fluorescent emission,while the fluorescent emission of NBO-PLA and NBS-PLA is weak or even invisible to the naked eye,and red phosphorescence emission will appear in vacuum,the lifetime is about 30 ms,which is slightly longer than the phosphorescence lifetime(<10 ms)of conventional pure organic RTP,new red phosphorescent units are prepared;by chang-ing different substituent groups,the fluorescence/phosphorescence emission ratio of such luminescent materials can be adjusted.The phosphorescence emission ratio is in-creased from 0.95:0.05 in NEG-PLA to 0.20:0.80(NBO-PLA)to 0.12:0.88(NBS-PLA).The influence of D,L-PLA and L-PLA on RTP emission were compared quali-tatively.The RTP emission brightness of D,L-PLA was brighter,while the emission wavelength of L-PLA was relatively longer.