共轭席夫碱及其铁盐的制备、表征及吸波性能研究

发布时间：2018-03-27 11:29

本文选题：共轭席夫碱及其铁盐　切入点：合成与表征　出处：《桂林理工大学》2017年硕士论文

【摘要】：共轭类席夫碱是一类主链有着大π键的二维平面化合物,主要结构中由C=N双键连接而成,这类化合物电子云分布均匀,离域程度较大,其结构可通过化学或电化学等方式进行修饰,进一步扩大席夫碱化合物的共轭体系。吸波材料是一种能够吸收电磁波的材料,以强大的吸收和损耗回波信号来降低其被探测到的可能性,可应用于较宽频带的不同领域范围。而共轭类席夫碱利用其共轭体系的平面构型,通过掺杂、配位等修饰手段改变或增强其导电结构,实现阻抗匹配和衰减匹配,从而达到吸波的目的。本文基于这一原理设计并合成了三种不同体系的共轭类席夫碱及其铁盐的吸波材料,并尝试了通过实验和理论研究对其本质进行探索。主要工作体现在以下几个方面:设计并合成了2-氨基芴类双席夫碱(L_1~L_3)及其铁盐(C_1~C_3)、三聚氰胺类三席夫碱(L_4~L_6)及其铁盐(C_4~C_6)及聚合物类席夫碱(L_7~L_9)及其铁盐(C_7~C_9)共三个体系18种物质,利用质谱分析(MS)、凝胶渗透色谱(GPC)、红外光谱分析(IR)、热重分析(TD/DTG)、紫外-可见光光谱分析(UV-Vis)、荧光光谱分析(PL)等手段对合成的物质进行了结构和性质的表征与分析。用四探针测试仪测定了这18种物质的电导率,其中体系I的结果呈现出L_2L_3L_1、C_2C_3C_1的规律,体系II呈现出L_4L_6L_5、C_4C_6C_5的规律,体系III呈现出L_7L_8L_9、C_7C_8C_9的规律。实验结果表明席夫碱成盐后,电导率可提高2~3个数量级,且每一个体系中也体现出共轭程度大小与电导率成正比的规律。对18种物质分别进行了吸波性能的测试,得出最终的最大反射损耗,三个体系中席夫碱最大损耗分别是L_2、L_4和L_7,分别为-3.157 dB(f=10.4 GHz,d=5 mm)、-10.918dB(f=12.16 GHz,d=4 mm)和-6.592 dB(f=15.04 GHz,d=5.5 mm),而三个体系中铁盐的最大损耗分别是C_2、C_4和C_7,分别为-27.229 dB(f=16.72 GHz,d=5 mm)、-21.783 dB(f=12.56 GHz,d=5 mm)和-17.482 dB(f=12.24 GHz,d=3.5 mm)。采用密度泛函理论(DFT),对合成的9种席夫碱进行了几何结构的优化,利用SPSS Statistics 19.0软件通过逐步多元线性回归的方法,分别对三个体系建立了定量构效关系,结果表明C=N双键的键长、电导率和某些重要原子的净电荷是影响其吸波性能的主要因素。
[Abstract]:Conjugated Schiff bases are a class of two-dimensional planar compounds with large 蟺 bonds in the main chain. The main structures are connected by Con N double bonds. The electron clouds of these compounds are uniformly distributed and have a large degree of delocalization. Its structure can be modified by chemical or electrochemical methods to further expand the conjugate system of Schiff base compounds. Using strong absorption and loss echo signals to reduce the possibility of detection can be applied to different fields in a wide frequency band, while conjugated Schiff bases use the plane configuration of their conjugated systems by doping, In this paper, three kinds of conjugated Schiff bases and their iron salts have been designed and synthesized based on this principle by modifying or enhancing the conductive structure of the complexes, so as to achieve impedance matching and attenuation matching, so as to achieve the purpose of absorbing waves. The main work is as follows: the design and synthesis of 2-aminofluorene double Schiff base (L1L3) and its iron salt C1C3C _ 3, melamine triSchiff base LSchiff _ 4L _ (6)) and its iron are designed and synthesized by means of experiments and theoretical studies, and the following are the main works: the design and synthesis of 2-aminofluorene double Schiff base (L1 / L _ (3))) and its iron salt (C _ (1) C _ (3)). And the polymer Schiff base L7 / L _ 9) and its iron salt _ _ _, The structure and properties of the synthesized materials were characterized and analyzed by mass spectrometry, gel permeation chromatography (GPC), IR, TD / DTG, UV-VisT and fluorescence spectra. The conductivity of these 18 substances was measured by a probe tester. Among them, the results of system I show the regularity of Lstag _ 2L _ 3L _ _ _. In each system, the conjugation degree is proportional to the conductivity. The absorbing properties of 18 kinds of materials are tested, and the ultimate maximum reflection loss is obtained. The maximum loss of Schiff base in the three systems is -3.157 dB(f=10.4 / L _ S _ 4 and L _ 7, respectively, -3.157 dB(f=10.4 / GHz / d ~ (5 mm) and -17.482 dB(f=15.04 / g ~ (2) dB(f=15.04 / d ~ (5 mm)) and -6.592 dB(f=15.04 / g ~ (2) / h ~ (5) mm respectively. The maximum loss of iron salt in the three systems is -27.229 dB(f=16.72 / GHz _ (5 mm) and -17.482 dB(f=12.24 GHz _ d _ (5 mm) and -17.482 dB(f=12.24 GHz _ d _ (5 mm) respectively. The maximum loss of iron salt in the three systems is -27.229 dB(f=16.72 GHz _ d _ (5 mm) and -17.482 dB(f=12.24 ~ (?) GHz _ d _ (5 mm) respectively. The maximum loss of iron salt in the three systems is -27.229 dB(f=16.72 GHz _ d _ (5 mm) and -17.482 dB(f=12.24 GHz _ d _ (5 mm). The geometric structure of 9 Schiff bases was optimized by functional theory. Using SPSS Statistics 19.0 software, the quantitative structure-activity relationships were established for the three systems by stepwise multivariate linear regression. The results show that the bond length, conductivity and net charge of some important atoms are the main factors that affect the absorbing properties of the three systems.
【学位授予单位】：桂林理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O641.4

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