含胆固醇和 4-(反式-正烷基环己基)苯甲酸结构单元的双液晶基元液晶化合物的合成及其性质

本文合成了一系列含有胆固醇和4-（反式-正烷基环己基）苯甲酸结构单元的新型双液晶基元液晶化合物。这些化合物中两个介晶基元是利用不同长度的氧烷酰基连接在一起。利用FT-IR、MS、1H NMR、POM、DSC 表证了所得化合物的结构和介晶性,并选择几种双液晶基元液晶测定了它们的机械黏度和在主体液晶中的螺旋扭曲力（HTP)。结果表明,绝大多数化合物显示较低相变温度的胆甾相（N*）,并且被选择的化合物的平均机械黏度和螺旋扭曲力类似于或优于胆甾醇任酸酯。     

反-4-(反-4′-丙基环己基)环己基甲酸的新合成方法

环己烷类液晶具有较高的相变温度和较低的粘度,克服了目前仍广泛使用的联苯类液晶相变温度低、粘度大、响应速度较慢的缺点,这类液晶材料已日益成为中高档混合液晶材料不可缺少的有效组分[1]. 反-4-(反-4′-丙基环己基)环己基甲酸(trans-3HHA)是合成这类液晶材料很重要的中间体,因此,它的合成具有重要应用价值. Trans-3HHA合成需经2步反应:加氢和异构化. 加氢反应以4-(反-4′-丙基环己基)苯甲酸(3HPA)为反应物,在加氢催化剂存在下,生成包含trans-3HHA和顺-4-(反-4′-丙基环己基)环己基甲酸(cis-3HHA)2种异构体的混合物(合称3HHA). 其中反式异构体trans-3HHA含量很低,必须进行异构化反应,使cis-3HHA转变为trans-3HHA. 文献报道有几种方法,如顺式或顺反-4-烷基环己基甲酸混合物在盐酸水溶液[2]、氢化钠乙醇溶液[3]和氢氧化钠水溶液[4]中,加热进行异构化反应. 但得到的产物反式与顺式异构体质量比都在75∶ 25～85∶ 15之间,需经多次重结晶才能得到反式异构体,产率低于70%. 本文以氢氧化钾为催化剂,加氢产物3HHA在无溶剂的条件下进行异构化,产物反式与顺式异构体质量比达到98∶ 2,产率＞90%.     

Synthesis and Properties of Poly （aryl ether ketone） Copolymers Containing 2,7-Naphthalene Moieties

IntroductionPoly(aryl ether ketone)s are high performance en-gineering plastics with outstanding physical,chemical,thermal and mechanical properties and have been ap-plied to the aerospace industry,the electronic industry,the automobile industry,the petro…     

对三氟甲基苯甲酸和2，2′-联吡啶双核铽配合物的合成、晶体结构及发光性质

A new dinuclear complex [Tb₂(BA)₆(2,2′-bipy)₂] (BA=4-(trifluoromethyl)benzoic acid, 2,2′-bipy=2,2′-bipyridine) has been synthesized. The complex was characterized by X-ray single-crystal structure analysis. The complex is a dimer with an inversion center. In the complex, two Tb3+ ions are linked by four carboxylate groups of BA ligands in bridging-bidentate coordination mode. Each Tb³⁺ ion is eight-coordinated with two nitrogen atoms from one 2,2′-bipy molecule, four oxygen atoms from four bridging-bidentate BA ligands and two oxygen atoms from one chelating-bidentate BA ligand. Intermolecular hydrogen bonds are formed in the crystal. The complex exhibits strong green fluorescence under ultraviolet light and the fluorescence spectrum consists of four lines peaking at 489, 545, 584 and 620 nm, which are corresponding to the ⁵D₄→⁷F_j (j=6～3) transitions of Tb³⁺ ion, respectively. CCDC: 727763.     

反式-1,4-二芳基环己烷类液晶的合成及性能研究

合成了一系列反式－1，4－二芳基环己烷类液晶化合物，总收率11．0％－27．5％，较文献收率有显著提高；并用IR和1H NMR进行了结构鉴定，通过配方研究，发现该系列化合物具有低阈值的特性，应用前景广阔。     

反-4-(反-4'-正丙基环已基)环已醇的合成与表征

环己烷类液晶因具有高度的稳定性,较宽的相列相温区而受到人们的青睐。反-4-(反-4’-正丙基环己基)环己醇(trans-3HHE)是一种合成环己烷类液晶的重要中间体,它可通过酶选择性催化和顺式构型异构化二种方法合成。文献报道顺式构型异构化法是：4-(反-4’-正丙基环己基)苯酚以铑／碳或铑／氧化铝为催化剂,在酸性介质条件下进行加氢反应,     

Synthesis and Magnetic Properties of Polyamide Complex Containing Bithiazole Moieties

A new polyamide containing bithiazole moieties （PTA） was synthesized by the polycondensation of 2, 2＇-diamino-4, 4＇-bithiazole （DABT） and oxalyl chloride. The polymer complex was prepared from PTA and NdC13 in DMSO. They were characterized through IR and elemental analysis. The preliminary magnetic properties of the complex PTA-Nd^3＋ was investigated, it was found that the material is a ferromagnet at low temperature.     

Synthesis,Characterization, and Comparative Study of Some Heterocyclic Compounds Containing Isoniazid and Nicotinic Acid Hydrazide Moieties

Russian Journal of Organic Chemistry - Some new derivatives of six-membered heterocyclic compounds containing isoniazid and nicotinic acid hydrazide fragments have been synthesized according to...     

卤代-2-(3-甲基-5-取代-4H-1,2,4-三唑-4-基)-苯甲酸的合成

邻氮基苯甲酸;缩合反应;卤代-2-(3-甲基-5-取代-4H-1;2;4-三唑-4-基)-苯甲酸的合成     

氯代二氮杂萘联苯型聚醚酮的合成及性能

聚醚醚酮（ＰＥＥＫ）是英国ＩＣＩ公司开发成功的结晶性热塑型耐高温工程塑料，具有许多优良性能，其玻璃化转变温度高达１４３℃，大量应用于电气、电子、机械、医疗、食品及航天航空领域［１，２］．只溶于浓硫酸，不溶于普通溶剂，使应用范围受到一定的限制．酚酞型聚...     

反-4-羟甲基哌啶-3-醇的合成

以4-羟甲基吡啶为原料,经苄基保护、硼氢化钠的还原、硼氢化氧化和脱苄基保护等四步反应得到新型5-羟色胺受体激动剂的关键中间体反-4-羟甲基哌啶-3-醇。总收率达55. 7%。产物结构经IR、1H NMR和MS分析确证,并对合成工艺进行了优化。     

含苯乙炔的可自交联高温高性能聚芳醚酮的合成与性能

将可交联的苯乙炔结构引入到热塑性聚芳醚酮链中, 并对其交联前后的性能进行了深入研究.     

Light-induced Photoswitching of 4-(Phenylazo)benzoic Acid on Au(111)

Photochromic molecules can undergo a reversible conversion between two isomeric forms upon exposure to external stimuli such as electromagnetic radiation. A significant physical transformation accompanying the photoisomerization process defines them as photoswitches, with potential applications in various molecular electronic devices. As such, a detailed understanding of the photoisomerization process on surfaces and the influence of the local chemical environment on switching efficiency is essential. Herein, we use scanning tunneling microscopy to observe the photoisomerization of 4-(phenylazo)benzoic acid (PABA) assembled on Au(111) in kinetically constrained metastable states guided by pulse deposition. Photoswitching is observed at low molecular density and is absent in tight-packed islands. Furthermore, switching events were noted in PABA molecules coadsorbed in a host octanethiol monolayer, suggesting an influence of the surrounding chemical environment on photoswitching efficiency.     

4-[(1,3-二氧代丁基)氨基]苯甲酸稀土配合物的合成、表征及发光性质

在乙醇体系中,由主配体4-[(1,3-二氧代丁基)氨基]苯甲酸(H2L,C11H11NO4)、稀土硝酸盐及辅助配体邻菲啰啉(phen)反应合成了两个系列8个配合物[Ln2(L)3(H2O)4]n(Ln=Sm(1),Eu(2),Tb(3),Dy(4));[Ln2(NO3)2(L)2(phen)2]n(Ln=Sm(5),Eu(6),Tb(7),Dy(8))。用元素分析、红外光谱、摩尔电导、热重分析进行表征,确定了产物的化学组成,推断了相应的结构。测定了室温时固体产物的激发和发射光谱,结果表明:由主辅配体共同配位的三元配合物的发光强度好于无辅助配体参与的二元配合物。测定了三元配合物的荧光寿命,其中铕和铽配合物显示较长的荧光寿命。     

二苯乙烯氨基酸的合成及其性能研究

以4-碘-L-苯丙氨酸为初始原料，先将羧基和氨基进行保护、后与苯乙烯进行Heck反应，最后在碱性和酸性条件下脱除保护合成二苯乙烯氨基酸，即(E)-2-氨基-3-(4-苯乙烯基苯基)丙酸的盐酸盐（4），产率53.7%，其结构经¹H NMR、 IR和HR-MS(ESI-TOF)表征。光学性质研究结果表明：4的激发波长为312 nm，发射波长为357 nm，斯托克斯位移为45 nm，荧光量子产率为0.09。 4在甲醇溶液中存在光致顺反异构现象，反式→顺式结构转变速率常数为0.046 min^-1。     

含辣素衍生结构疏水缔合聚合物PAAH的合成、表征及溶液性质

以辣素功能结构单体N-（4-羟基-3-甲氧基-苄基）-丙烯酰胺（HMBA）为疏水单体,与丙烯酰胺（AM）和2-丙烯酰胺基-2-甲基丙磺酸钠（NaAMPS）通过自由基胶束共聚,制得三元疏水缔合聚合物P（AM-NaAMPS-HMBA）（简称PAAH）. 采用紫外-可见光谱、核磁共振氢谱、热重分析及扫描电子显微镜对共聚物的结构及形貌进行表征,利用原子力显微镜对聚合物水溶液的微观形貌进行观察,并对其溶解性、疏水缔合性、耐温性及抑菌性能进行了研究. 结果表明,所得共聚物中疏水单体含量与投料比基本一致;PAAH具有良好的速溶性,当聚合物浓度超过一定值后,溶液黏度急剧增加,且随着疏水单体含量增加,疏水缔合性能增强;原子力显微镜观察证实了聚合物水溶液中网络结构的存在. 与未改性的P（AM-NaAMPS）（简称PAA）共聚物相比,引入具有生物活性且带有刚性苯环结构的HMBA单体可使PAAH共聚物热稳定性增强,耐温性能提高,并赋予其优良的抑菌性能.     

Synthesis and Properties of New Laser Dyes Containing 4-(2-Thienyl)Pyridine Skeleton

Abstract

Three 4-(oligothienyl)pyridines and four α,ω-di(4-pyridyl)oligo-thiophenes were prepared and the effect of conjugated thiophene rings on their fluorescence properties were examined. 4-(2,2′-Bithienyl-5-yl)pyridine and 2,5-di(4-pyridyl)thiophene exhibited laser dye emission upon pumping with a nitrogen laser and the conversion efficiency of the latter was 1.5 times as great as that of a commercial laser dye PBBO at 400 nm.