New long-chain donor-acceptor-donor pyromellitic diimide (PMDI) derivatives. A combined theoretical and experimental study
作者:Alexandre Gonçalves Dal-Bó、Rodrigo da Costa Duarte、Rodrigo Cercená、Michael Peterson、Jamal Rafique、Sumbal Saba、Eduardo Zapp、Eduarda Sangiogo Gil、Paulo Fernando Bruno Gonçalves、Fabiano Severo Rodembusch、Tiago Elias Allievi Frizon
DOI:10.1016/j.dyepig.2018.04.053
日期:2018.10
bisimide moiety showed two waves due to the formation of both the radical anion and a dianion. On the other hand, oxidation showed two waves due to the formation of radical cations and dications. The thermal properties were measured by differential thermal analysis (DTA) and thermogravimetric analysis (TGA), and the materials showed high thermalstability (Td > 300 °C). Theoretical calculations were
这项研究涉及新的均苯四酸二亚胺(PMDI)衍生物的电化学,热学和光物理分析,这些衍生物含有不同大小的烷基链。光物理研究表明,所有化合物均在UV-B区域(约290 nm)表现出吸收。通过约4.03 eV的起始峰值计算带隙。的化合物是在UV-A区域(312-328纳米)在激发态小溶剂化变色效果的光敏(Δλ EM = 16 nm)。电化学研究表明,由于自由基阴离子和二价阴离子的形成,双酰亚胺部分的还原显示出两个波。另一方面,由于自由基阳离子和阳离子的形成,氧化显示出两个波。通过差示热分析(DTA)和热重分析(TGA)测量热性能,材料显示出高的热稳定性(T d > 300°C)。还进行了理论计算以研究这些化合物在其基态和激发电子态下的几何形状和电荷分布。通过改变附着在PMDI结构上的溶剂或取代基,没有发现吸收和发射最大值的显着变化。
Benzene ring containing cationic gemini surfactants: Synthesis, surface properties and antibacterial activity
a pronounced effect on the aggregation behavior of surfactants molecules. This was confirmed by the average surfaces occupied by these molecules at the water–air interface calculated from the Gibbs equation. The size of the aggregates was measured by employing dynamic light scattering technique. The antimicrobial activity of investigated surfactants was evaluated against three microorganisms: Staphylococcus
通式为C n H 2n + 1 -Ph-NHCOCH 2 N +(CH 3)2-(CH 2)s -N +(CH 3)2 CH 2 CONH-Ph-C n H的新型季铵双子表面活性剂通过基于N,N,N ',N的季铵化的有效合成途径合成了2n +1(n = 8、10、12、14、16和s = 2、4、6)′-四甲基亚烷基二胺与2-溴-N-(4-(烷氧基)苯基)乙酰胺。通过表面张力,电导率和动态光散射(DLS)测量研究了它们的表面性能。研究表明,在疏水尾部掺入苯环会促进胶束形成,与带有烷基疏水链的类似双子星相比,胶束的cmc值较小,在0.21-0.009 mM范围内。间隔基和疏水链的长度对表面活性剂分子的聚集行为具有显着影响。由吉布斯方程计算得出的这些分子在水-空气界面处所占据的平均表面可以证实这一点。聚集体的尺寸通过采用动态光散射技术来测量。金黄色葡萄球菌,大肠杆菌和白色念珠菌。
Synthesis and characterization of azobenzene derivatives and azobenzene-imidazolium conjugates with selective antimicrobial potential
while Gramnegative strains exhibited a cut-off effect at chain length C16. Difference in antimicrobial behavior of the azo derivatives could be due to the different cell wall between the Gram positive and negativebacteria. Fluorination had no effect on the activityagainst E. coli and Salmonella. However, a clear correlation between the level of fluorine substitution and the antimicrobial activity
The First tetrafluorinated azobenzene-imidazolium ionic conjugates as potential thermotropic liquid crystalline drugs: Self-assembly properties and cytotoxic effects
作者:Halimah Funmilayo Babamale、Boon-Keat Khor、Nelson Jeng-Yeou Chear、Rosenani A. Haque、WanSinn Yam
DOI:10.1016/j.molstruc.2022.132470
日期:2022.5
A new series of tetrafluorinated azobenzene-imidazolium ionicliquidcrystals (ILCs) of varying alkyl chain length (n = 10-18 in even parity) in the imidazolium cationicheadgroup was prepared and characterized using FTIR and NMR spectroscopy, and elemental microanalysis. Their thermal and phase properties were investigated using differential scanning calorimetry (DSC) and polarized optical microscope
A molecular insight on the supramolecular assembly of thiophene polymers
作者:Chandrasekaran Suryanarayanan、Ezhakudiyan Ravindran、Soundaram Jeevarathinam Ananthakrishnan、Narayanasastri Somanathan、Asit Baran Mandal
DOI:10.1039/c2jm30550j
日期:——
Herein, the relationship between supramolecularly self-assembled microstructures and the chemical structures of photoluminescent molecules is discussed. A series of non-amphiphilic molecules with different length alkyl chains (4–14), central mesogenic groups, and chemical linkers were designed and synthesized. Intricate analysis shows that the supramolecular assembly varies with change in torsion angle of the thiophene linking group on elongation of the alkyl chain. Small angle X-ray scattering measurement shows long range molecular interaction for lower alkyl chain length, AFM reveals circular domains for octyl and decyl alkyl group polymers. UV-Visible and photoluminescence studies in solution and thin-film show that the J-aggregate patterns for the circular domain of the polymer backbone has a major effect on the polymer absorbance, and produces a larger shift for the photoluminescence signals at higher wavelengths. Excitation polarisation studies show a change in molecular ordering in various colour regions with change in aggregation by means of maximum dichroic ratio for the circular domain assembly. Charge carrier mobility and cyclic voltammetry studies show higher mobility and reduced band gap for these circular domain polymers. Dynamic light scattering studies of octyl alkyl chain polymers show a bimodal distribution, which shows the apparent nature of anisotropy in solution.
本文讨论了超分子自组装微结构与光致发光分子化学结构之间的关系。研究人员设计并合成了一系列具有不同长度烷基链(4-14)、中心介原基团和化学连接体的非两亲分子。复杂的分析表明,烷基链伸长时,噻吩连接基团的扭转角发生变化,超分子组装也随之变化。小角 X 射线散射测量显示,烷基链长度较低时,分子间的相互作用范围较长;原子力显微镜显示,辛基和癸基烷基聚合物具有圆形结构域。溶液和薄膜中的紫外可见光和光致发光研究表明,聚合物骨架环形结构域的 J-聚合模式对聚合物的吸光度有重大影响,并在较高波长下产生较大的光致发光信号偏移。激发偏振研究表明,随着环形结构域组装的最大二色性比率发生变化,不同颜色区域的分子有序性也发生了变化。电荷载流子迁移率和循环伏安法研究表明,这些环状结构域聚合物的迁移率更高,带隙更小。辛基烷基链聚合物的动态光散射研究显示出一种双峰分布,这表明了溶液中各向异性的明显性质。