本科生有机化学实验与前沿科学研究的融合—四(4-甲基苯基)乙烯的合成、表征及聚集发光性能研究

四苯乙烯(TPE)及其衍生物,作为一类典型的聚集诱导发光分子,由于其合成简单、易于修饰和发光性能优异等优点,已被广泛的应用于化学生物传感器、生化检测、生物成像和有机光电材料等领域。在此,我们将聚集诱导发光这一前沿研究热点融入有机化学实验教学中,进行教学对象为化学专业本科生的前沿有机化学实验设计：四(4-甲基苯基) 乙烯的合成、表征及聚集发光性能研究。该实验内容包括通过McMurry 偶联反应合成四(4-甲基苯基) 乙烯、四(4-甲基苯基) 乙烯的结构表征,以及利用紫外-可见分光光度计和荧光光谱仪对其聚集诱导发光性能进行研究。通过本实验,使学生了解聚集诱导发光这一科学研究前沿领域,激发学生对科学研究的兴趣、拓展科研视野、激发科研热情、培养学生的科研探究能力。本实验综合了有机化学、仪器分析和发光材料等知识点的学习,培养学生的实验操作技能,提升学生的综合及创新能力,建议纳入高年级中级有机化学实验课程。     

二咔唑四苯乙烯多功能发光化合物的合成与性能

合成了一种新型的具有压致荧光变色效应的聚集诱导增强发光(PAIE)化合物二咔唑四苯乙烯; 通过核磁共振、质谱和元素分析等手段对其进行了结构表征; 利用紫外吸收光谱、荧光发射光谱、热分析和X射线衍射等手段研究了化合物的基本性能. 实验结果表明, 随着水含量的增加, 该化合物溶液荧光强度增强了171倍, 荧光量子产率提高了100倍, 表现出明显的聚集诱导增强发光效应; 在外界因素作用下该化合物固体样品可实现结晶态与无定形态的相互转变. 结晶态的荧光发射波长为450 nm, 无定形态为480 nm, 相差30 nm, 说明该化合物具有明显的压致荧光变色效应; 将该化合物用于制备发光器件, 未经优化的器件亮度达2438 cd/m², 电流效率为2.87 cd/A, 流明效率为1.81 lm/W. 该化合物是一种多功能材料.     

三芳胺-吡嗪类供体-受体型聚集诱导发光分子的合成及性能表征综合创新实验

为了提升学生的基础有机合成技能及综合实验创新能力,介绍了一类含三芳胺及吡嗪单元的供体-受体型聚集诱导发光分子的合成、性能表征及分析。通过本综合创新实验的学习,学生将进一步了解有机荧光材料,尤其是聚集诱导发光材料的发光机理及潜在应用。本实验不仅有利于提升学生在减压蒸馏、萃取、干燥和柱层析分离等操作方面的实验技能,也将进一步促进其对核磁共振仪、高分辨质谱仪、紫外-可见吸收光谱仪及稳态-瞬态荧光光谱仪等仪器的熟悉和掌握。最终,通过课堂理论及综合实验学习的相互结合,进一步拓展学生视野并锻炼学生综合创新实验能力,为培养其良好的科学研究素养奠定基础。     

有机化学综合实验:基于联二萘酚手性聚集诱导发光分子的合成、表征及性质研究*

将前沿科学成果引入大学有机化学综合实验课中,设计了基于联二萘酚手性聚集诱导发光分子的合成、表征及性质研究的有机化学综合实验。通过本实验,学生将掌握几类经典的有机反应,包括酚羟基保护、芳基甲酰化及缩合等反应的基本原理及操作,熟悉核磁共振、质谱等结构表征手段以及紫外-可见吸收光谱、荧光光谱以及圆二色光谱等性质表征技术,了解聚集诱导发光现象及机理。本实验综合了多种有机反应及性质表征技术,有利于提升学生的综合实验能力、科学研究思维并激发学生对科学研究的兴趣。     

四苯乙烯的合成、表征及在爆炸物检测中的应用 ——介绍一个大学化学综合实验

因具有聚集诱导发光特性、螺旋桨结构的四苯乙烯及其衍生物,在有机光电材料、荧光传感和生物成像等领域表现出优异的荧光性能。本实验以二苯甲酮为原料,利用McMurry偶联反应合成四苯乙烯。采用萃取、干燥和柱层析等手段对产物进行分离和纯化,通过熔点测定、核磁共振氢谱、核磁共振碳谱和质谱对其结构进行表征后,使用苦味酸作为模型化合物,利用荧光光谱测定其对爆炸物的荧光检测极限。本实验寓科研热点于实验教学中,不仅提高了学生的实验操作技能,而且有助于学生了解具有聚集诱导发光性能的四苯乙烯及其衍生物的研究现状和应用前景,激发了学生的科研兴趣和创新意识。     

聚集诱导发光新材料9,10-双[2-(1-甲基-1H-吡咯-2-基)乙烯基]蒽的 合成及性能

合成并全面表征了一种新的蒽烯类化合物9,10-双[2-(1-甲基-1H-吡咯-2-基)乙烯基]蒽(MPVAn). 该化合物具有显著的聚集诱导发光特性. 它在溶液态时几乎不发光, 但在固态时的光致发光强度达到溶液态的数百倍. 为了确定标题化合物的聚集诱导发光机制, 研究了它在不同溶液粘度及温度下的光致发光行为, 结果表明聚集态发光增强是由于分子内转动受阻所致. 它的粉末在420 nm光的激发下发射纯的黄光, 峰值为562 nm, 半峰宽为66 nm. 采用紫外-可见吸收光谱及循环伏安法研究了化合物的电子性能, 其HOMO和LUMO能级分别为－4.78和－2.28 eV.     

四苯乙烯和三苯乙烯修饰的8-羟基喹啉聚集诱导发光特性研究

将2-甲基-8-羟基喹啉与四苯乙烯或三苯乙烯基团结合,合成了两种新型喹啉衍生物(4-Br-TPE-8HQ及TriPE-8HQ),并对其进行了光物理性能研究。结果发现,连接有四苯乙烯的喹啉衍生物能够体现聚集诱导发光(AIE)特性,而连接三苯乙烯的喹啉衍生物却显示温和的聚集诱导猝灭(ACQ)效应,实现了通过功能基团来调节目标分子聚集诱导效应的目的。研究发现,不同体系下分子的整体平面性有所不同,其中三苯乙烯修饰的衍生物在溶液中的荧光寿命(0.55 ns)高于固体荧光寿命(0.43 ns);循环伏安法证明两者具有良好的电化学稳定性,计算得到的4-Br-TPE-8HQ和TriPE-8HQ的LUMO能级分别为-2.40 eV和-2.43 eV,表明为两个化合物注入电子是可行的。     

5-甲氧基-2-苯基-2, 3-二氢苯并呋喃的制备——介绍一个大学综合化学实验

介绍了一个大学综合化学实验。该实验以对甲氧基苯酚和苯乙烯为原料,六氟异丙醇为溶剂,2,3-二氯-5,6-二氰基-1,4-苯醌为氧化剂,室温合成5-甲氧基-2-苯基-2,3-二氢苯并呋喃,并用IR、1H NMR、13C NMR和HRMS对产物结构进行表征。本实验有益于激发学生的科研兴趣和探索精神,训练学生的综合实验操作技能和分析能力,培养学生的创新思维和科研能力。     

反式-4，4′-二（邻甲氧基苯乙烯基）联苯化合物的合成、结构及光物理性能

以wittig—Homer反应合成了反式对称的4,4′-二（邻甲氧基苯乙烯基）联苯化合物,X射线衍射分析测定了化合物的晶体结构．测定了其在不同溶剂中的线性吸收光谱、荧光发射光谱及荧光量子产率．飞秒激光做光源研究了化合物的双光子光物理性能．测试结果表明：该化合物在蓝光波段有较强的荧光发射,化合物具有较高的荧光量子产率和较大的双光子吸收截面,具有双光子诱导蓝光发射光学特性．     

高对比度多色力致发光变色二苯并富烯衍生物的设计合成及性质研究

制备了苯基甲苯基二苯并富烯（phenyltolyldibenzofulvene,1）并研究了其发光性能.化合物1具有聚集诱导发光（aggregation induced emission,AIE）及结晶诱导荧光增强（crystallization enhanced emission,CEE）的性质,且化合物1可形成蓝色、蓝绿色荧光的晶体以及黄绿色荧光的无定形态.因化合物1分子为扭曲的螺旋桨构象,分子在聚集态中以较疏松的形式堆积,故化合物1可在热、溶剂气氛以及外力刺激下发生多种聚集态间的可逆转变,从而实现在三种不同发光状态间的可逆转变.我们尝试将化合物1用于光学记录,以单一化合物1为发光材料,其可在蓝绿及蓝色荧光颜色背景上以暗黄绿色字迹记录,可通过研磨、加热及溶剂气氛处理擦除字迹,并将记录纸分别转变为蓝色、蓝绿色及黄绿色,因此化合物1有望用于光存储材料.     

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性

PMDA-BPDA-HAB聚苯并噁唑的合成及耐热性;均苯四甲酸二酐;联苯四羧酸二酐;二羟基联苯胺;聚酰亚胺;聚苯并噁唑;耐热性     

Multi-instrument characterization of HiPIMS and DC magnetron sputtered tungsten and copper films

In this work, copper and tungsten were sputtered onto silicon wafers by direct current magnetron sputtering (DCMS) and high-power impulse magnetron sputtering (HiPIMS). The resulting films were characterized by energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), spectroscopic ellipsometry (SE), and X-ray diffraction (XRD). By EDX and XPS, all the sputtered films showed only the expected metal peaks. By XPS, the surfaces sputtered by DCMS were richer in oxygen than those produced by HiPIMS. By AFM, the surfaces were quite smooth. The root mean square (RMS) roughness values are as follows: 0.83 nm (W, HiPIMS), 1.10 nm (W, DCMS), 0.85 nm (Cu, HiPIMS), and 1.78 nm (Cu, DCMS). By SEM, the HiPIMS films exhibited smaller grain sizes, which was confirmed by XRD. The crystallite sizes estimated by XRD are as follows: 4 nm (W, body-centered cubic, HiPIMS), 13 nm (W, body-centered cubic, DCMS), 7 nm (W, cubic, HiPIMS), 14 nm (W, cubic, DCMS), 25 nm (Cu, HiPIMS), and 35 nm (Cu, DCMS). By SE, the HiPIMS surfaces showed higher refractive indices, which suggested that they were denser and less oxidized than the DCMS surfaces.     

HCOO在Cu(110)、Ag(110)和Au(110)表面的吸附

采用密度泛函理论(DFT)以及广义梯度近似方法(GGA)计算了甲酸根(HCOO)在Cu(110)、Ag(110)和Au(110)表面的吸附. 计算结果表明, 短桥位是最稳定的吸附位置, 计算的几何参数与以前的实验和计算结果吻合. 吸附热顺序为Cu(110)(-116 kJ·mol-1)>Ag(110)(-57 kJ·mol-1)>Au(110)(-27 kJ·mol-1), 与实验上甲酸根的分解温度相一致. 电子态密度分析表明, 吸附热顺序可以用吸附分子与金属d-带之间的Pauli 排斥来关联, 即排斥作用越大, 吸附越弱. 另外还从计算的吸附热数据以及实验上HCOO的分解温度估算了反应CO2+1/2H2→HCOO的活化能, 其大小顺序为Au(110)>Ag(110)>Cu(110).     

Magnetism of metal-nitroxide compounds involving bis-chelating imidazole and benzimidazole substituted nitronyl nitroxide free radicals

Coordination compounds based on imidazole and benzimidazole substituted nitronyl nitroxide radicals with transition metal ions and trivalent lanthanide ions are described from the perspective of their magnetic properties.For the transition metal compounds the crystal structures show various metal-nitroxide dimensionalities including mononuclear (0D), one-dimensional (1D) and two-dimensional (2D) complexes. The mononuclear complexes were isolated with most metal ions of the first transition series. One copper(II) complex shows a copper(II)-radical ferromagnetic coupling (J = +75 cm⁻¹) while for the other mononuclear compounds, mainly with manganese(II), the metal-radical interactions are antiferromagnetic. The one-dimensional and two-dimensional complexes are manganese(II) compounds which show canting effects leading to weak ferromagnetism.For the trivalent lanthanide ions [La(III), Gd(III) and Eu(III)], three series of mononuclear complexes were obtained in which the metal center is bound to four, two or one nitroxide radicals depending on the counter ions and ancillary ligands. Unexpectedly, in most gadolinium(III) complexes, the Gd(III)-radical interactions were found to be antiferromagnetic in contradiction with other foundings and previous theoretical models. In support to the magnetic studies, the optical properties of the lantanide complexes have also been investigated and are briefly described.     

Mononuclear and homobinuclear cobalt(II), nickel(II) and copper(II) complexes with mono and bis-azocompounds derived from 2,7-dihydroxynaphthalene and anthranilic acid or o-aminophenol

Two new series of mononuclear and homobinuclear Co(II), Ni(II) and Cu(II) complexes with mono- and bis-azo compounds derived from 2,7-dihydroxynaphthalene and anthranilic acid or o-aminophenol are prepared and characterized by elemental and thermal analyses, conductance, IR, electronic, ESR spectra and magnetic moment measurements. The ligand field splitting parameters and Racah constant are calculated. The spectral and magnetic results obtained are utilized to determine the geometries around the metal(II) ion. The geometry of the complex formed depends on the structure of the ligand and the type of metal(II) ion. The mode of bonding of the ligand with the metal ions is deduced from IR spectra.     

Synthesis and Characterization of A Vic-Dioxime Derivative and Investigation of its Complexes with Ni(II), Co(II), Cu(II) and UO2(VI) Metals

In this study, 1,2-dihdroxyimino-3,7-di-aza-9,10-O-iso-propylidene decane (LH₂ ) was synthesized starting from 1,2-O-iso-propylidene-4-aza-7-aminoheptane (RNH₂ ) and anti-chloroglyoxime. Complexes of this ligand with Ni(II), Co(II), Cu(II) and UO₂(VI) salts were prepared. Structures of the ligand and its complexes are proposed based on elemental analyses, IR, ¹³C and ¹H NMR spectra magnetic susceptibility measurements and thermogravimetric analyses (TGA).     

Silicification and biosilicification

Biosilicification takes place at or very close pH 7.0 and under ambient conditions of temperature and pressure in vivo. The silicic acid transporters and the proteins facilitating biosilicification in diatoms have been identified. Silica synthesis under mild conditions in vitro has been demonstrated using synthetic polymers with control over the resulting silica morphology. The results presented herein show that the silica synthesis in vitro is not specific to particular enzymes/polypeptides due to their particular chemical structure and activity but that many other synthetic macromolecules are also capable of facilitating silica formation at neutral pH. We also report the synthesis of organic-inorganic hybrid materials that have potential in optoelectronic applications.     

Simultaneous determination of mercury and arsenic by anodic stripping voltammetry

An electrochemical method for the simultaneous determinations of Hg^II concentration and total As^III and As^V concentration has been developed. The method does not require the additional preliminary step of the chemical reduction of As^V to As^III, or oxidation of As^III to As^V before stripping analysis takes place. Also, the method for the simultaneous determination of Hg^II concentration and As^III concentration is described. Measurements were performed in 0.1 M HCl using a gold-plated graphite electrode as sensor. Detection limits for both methods are below 0.4 ppb. Relative standard deviation did not exceed 15%. The possible interference by other trace metals was investigated. Analyses of natural water and industrial solutions were made using proposed methods and AAS. The t-test demonstrates that there was no significant difference between the results obtained with these methods. Proposed methods decrease the time of analysis because concentrations of the Hg^II and arsenic ions were measured simultaneously. Also, the removal of the additional step of chemical reduction of As^V to As^III or oxidation of As^III to As^V decreases analysis time, and also reduces the chance of contamination due to the use of additional reagents.     

Complexation and the laser luminescence studies of Eu(III), Am(III), and Cm(III) with EDTA,CDTA, and PDTA and their ternary complexation with dicarboxylates

Spectroscopy has been used to determine the number of coordinated water molecules bound to Eu(III) and Cm(III) in a series of binary complexes of polyaminocarboxylate and their ternary complexes with dicarboxylates as well as with similar ligands with additional O-, N-, and S-donors. Complexes of Eu(III) and Cm(III) with polyaminocarboxylate alone contain ca. 2.5–3.0 waters of hydration. Increasing the steric requirement of a polyaminocarboxylate by increasing the number of groups in the ligand backbone does not appreciably change the hydration of these cations. The stability constants of the binary and ternary complexes of Cm(III), Am(III), and Eu(III) with these ligands were measured by solvent extraction in a solution of 0.1 M (NaClO₄). The size, basicity, specific M³⁺-second ligand interactions, and steric requirement of the ligands are the factors which affect the ternary complexation. Knowledge of the chemical species formed by actinide cations with organic ligands (carboxylates and aminocarboxylates), which are present in all nuclear waste, is important to understand the behavior of waste forms and the migration behavior of actinides in the environment.     

Synthesis and Multinuclear NMR Study of Benzoyl Methylene Triparatolylphosphorane Ylide and the Reaction of this Ylide with Mercury(II) Halides

The reaction of the title ylide {PhCOCHP(p-tolyl)₃} with Pd(II), Pt(II). Hg(II), and Ag(I) in equimolar ratios using CH₃CN, CH₃OH, and CH₂Cl₂ as solvents have yielded [{(p-tolyl)₃PCHCOC₆H₅} PdCl₂]₂ (I), [{(p-tolyl)₃ PCHCOC₆H₅} PtCl₂]₂(2), [Hg(NO₃)₂ {(p-tolyl)₃ PCHCOC₆H₅}](3), and [Ag{(p-tolyl)₃ PCHCOC₆H₅ < eqid1 > ₂]⁺ (4). The IR, ¹H ¹³C, and ³¹P NMR together with micro analysis data of the products were obtained.