Synthesis and Physical Studies of the Organic Salts of Pindolol: Pindolol Benzoate and Pindolol 2-Methoxyphenylacetate

Abstract

In order to investigate the formation of organic salts of drugs, two salts of pindolol were prepared using salt-forming agents which were crystalline and suitable for physical studies in the solid state. The stoichiometry of the products, pindolol benzoate and pindolol 2-methoxyphenylacetate, was established by elemental analysis. The precipitates formed were assessed by differential scanning calorimetry (DSC), thermogravimetry (TG), x-ray powder diffractometry (XRPD) and Fourier transform-infrared spectrometry (FT-IR). According to the TG and DSC curves, there was no water of crystallization in the precipitates, and the products were thermally stable. Both precipitates gave one sharp melting endotherm which differed from the endotherms of the starting compounds. The x-ray dipaction pattern of the precipitates direred clearly from those of the starting materials, acid and base. The products showed absorption by FT-IR typical of carboxylic acid salts at about 1640-1540 cm^?1. The carbonyl absorption indicative of the carboxylic acid group of benzoic acid or 2-methonyphenylacetic acid was not detectable in the spectra of the precipitates. All this indicates that two new crystalline organic salts (1:1) were formed during the syntheses.     

Synergistic effect of two surface complexes in enhancing visible-light photocatalytic activity of titanium dioxide

Titanium dioxide nanoparticles with high visible-light photocatalytic activity were prepared by the solvothermal method with titanium tetra-n-butoxide as starting material in acetone. The products were characterized by XRD, TEM, TG–DTA, DRS and FT-IR. DRS results showed that the products, irrespective of their anatase or amorphous forms, had significant absorption in the visible-light region. The photocatalytic degradation of methyl orange solutions revealed that the anatase products had a higher visible-light photocatalytic activity than the amorphous ones. It is suggested that two surface complexes, formed between titanium dioxide and methyl orange molecules, and formed between titanium dioxide and the new organic moieties from the autoclaving, contribute synergistically to the high visible-light photocatalytic efficiency.     

Studies on salts of 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4,6-trinitroanilino benzoic acid (TABA): potential energetic ballistic modifiers

The Co/Cu/Ni/Fe salts of 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4,6-trinitroanilino benzoic acid (TABA) were prepared and characterized during this work. All the salts exhibited exothermic decomposition in DSC. The FT-IR spectra of the gaseous products evolved during TGA of NTO salts indicated the release of NO2 and cleavage of NTO ring during the course of decomposition. Thermal decomposition of TABA salts also produced NO2 on decomposition. The transition metal salts enhanced the burning rates of AP-HTPB composite propellant evaluated during this work. The best catalytic effect was obtained with Fe-NTO salt which increased the burning rate to the extent of approximately 80% as well as brought down the pressure index (n) to 0.18 (2-9MPa).     

UV固化丙烯酸双酯液晶的合成与性能

以1,4-苯二甲酸[二(4-羧基苯)]酯为介晶基元合成了一系列两端均含有丙烯酸双键的化合物,其结构通过了元素分析、FT-IR、质谱和1H-NMR等方法的确证。采用Netzsch DSC204差示扫描量热仪和Leica Orthoplan偏光显微镜对产物进行测试,结果表明其中两种单体具有向列型液晶的特征。混合光敏剂后,分别在高于清亮点温度、低于熔点温度,以及在液晶相温度范围内用紫外光辐射固化,固化过程通过FT-IR表征,用RIGAKU D/MAX-1200 X射线衍射测试表明在液晶相温度范围内光固化可形成具有液晶性的聚合物。     

荧光手性聚芳硫醚酰亚胺季胺盐的制备及表征

在制备PASI的基础上制备ASIHC,通过红外分析,核磁共振,紫外分析表征PASIHC的结构,旋光测试表明PASIHC具有手性结构,热分析表明PASIHC的热性能较聚芳硫醚酰亚胺略有升高.荧光分析表明PASIHC具有荧光性能.PASIHC作为光学器件和热敏元件具有良好的应用前景.为制备含有N原子的聚芳硫醚类树脂提供基础数据,为制备具有荧光性能和手性结构的聚芳硫醚类树脂提供新思路.     

溶胶-凝胶法制备多晶莫来石纤维

以廉价的铝粉、工业盐酸和酸性硅溶胶为主要原料, 通过溶胶凝胶法制备了多晶莫来石纤维. 采用²⁷Al NMR测试了聚合氯化铝溶胶中Al³⁺的聚集状态, 采用XRD、FT-IR、SEM和TG-DTA等手段表征了不同热处理温度下莫来石纤维的物相组成、纤维形貌以及纤维的热分解特性. ²⁷Al NMR结果表明, Al³⁺主要以Keggin结构的Al₁₃形态存在于聚合氯化铝溶胶中. 具有24个活性Al-OH键的Al₁₃聚阳离子易与硅溶胶中的Si-OH发生失水缩聚反应, 生成具有长链结构的纺丝溶液. XRD、FT-IR和TG-DTA结果表明, 纤维热处理到950℃时开始结晶, 到1000℃可获得单一的莫来石晶相, 整个过程的纤维失重在48.24％. 经1250℃热处理, 获得的莫来石纤维的直径为3～5μm, 晶粒尺寸约为240 nm, 拉伸强度为1.1GPa.     

桐油改性醇酸氨基水性绝缘漆的制备及性能

以桐油、顺丁烯二酸酐、邻苯二甲酸酐、月桂酸、三羟甲基丙烷为原料,六甲氧基甲基三聚氰胺树脂(HMMM)为交联剂,制备出桐油改性醇酸氨基水性绝缘漆,采用FT-IR、DSC和TG对涂料进行结构表征和性能测试.油度增大,漆膜的吸水率降低,电气强度增大,但树脂的水溶性变差,理想的油度为37%;HMMM的加入量增大,漆膜的玻璃化温...     

Chemical interactions between an active pharmaceutical ingredient and its counterion in a tromethamine salt under forced degradation conditions

In this study, the tromethamine salt of an active pharmaceutical ingredient containing both a carboxylic acid and ethyl ester functionality was subjected to forced degradation conditions. Based on HPLC-MS analysis, it was found that tromethamine formed both amide and ester type condensation products with the API, with amide formation predominating over ester formation. Addition of tromethamine at the carboxylic acid group of the API was favored over addition at the ethyl ester group. Tromethamine condensation products were observed only under the harshest stress conditions (80 degrees and 75% relative humidity), in which the salt physically changed from a crystalline form to a deliquesced state. Under stress conditions in which the crystalline structure of the salt remained intact, good stability was observed. Thus, the interaction between tromethamine and API occurred only in cases where the crystallinity of the salt was compromised.     

Comparative study of the molecular aggregation state of alkyl organic monolayers prepared on Si and hydrogen-terminated Si substrates

A comparative study of the molecular aggregation states of n-octadecyltrichlorosilane (OTS) and octadecene monolayers was carried out based on water contact angle, x-ray reflectivity (XR), grazing incidence x-ray diffraction (GIXD), and Fourier transform infrared spectroscopy (FT-IR) measurements. Water contact angle, XR, and FT-IR measurements revealed that the packing density and orientational order of the OTS were higher than those of octadecene. The OTS monolayer was in a hexagonal crystalline state with (10) spacing of 0.417?nm, whereas the octadecene monolayer was in an amorphous state. The growth mechanisms of the OTS and octadecene monolayers are also proposed. The alkyl molecular aggregation states strongly depended on the chemical bonding state at the interface between the alkyl organic molecule and the substrate surface.     

主链型偶氮苯改性聚芳酰胺的合成及表征

在以N,N二甲基乙酰胺为溶剂,三乙胺为酸吸收剂的条件下,将自制的反式-4,4'-偶氮苯二甲酰氯与对苯二胺进行低温缩聚反应,合成了1种新型的反式偶氮苯聚芳酰胺.用红外光谱、示差热扫描量热分析,热重分析,偏光显微镜,紫外光谱对其结构及性能进行了表征.合成的聚合物表现出了一定的结晶性能,聚合物的稀溶液呈现出溶致液晶行为.     

超临界CO2流体干燥合成ZrO2气凝胶及其表征

以无机盐为原料,采用沉淀法结合超临界CO2流体干燥技术成功地制备了ZrO2气凝胶.借助TG/DSC、XRD、TEM、DLS以及N2物理吸附等手段对其性能进行表征.结果显示,超临界CO2流体干燥可以有效地防止干燥过程中胶体粒子之间的硬团聚作用,在基本保持湿凝胶网络结构的情况下实现液相的脱除,从而使合成的ZrO2具有高比表面积和大孔体积等特点.此外,样品的TEM和DLS分析显示,纳米ZrO2颗粒首先形成具有空间网络结构的簇团,尺寸为数百个纳米的簇团堆积形成ZrO2气凝胶;气凝胶的空间网络结构特征在中等温度的热处理过程中不会遭到完全破坏.     

改性多省并醌的合成与性能研究

合成了两种新型蒽醌单体:1,4-二(辛氧基)蒽-9,10-二酮和1,4-二(丁氧基)蒽-9,10-二酮。通过红外、核磁和元素分析确证了单体的结构。DSC、TG结果显示两种新型单体的5%质量损失温度最高可达266.4℃。将新型蒽醌单体与均苯四甲酸酐在硝基苯中预聚,再将预聚产物在NaCl/AlCl3熔盐中继续反应得到改性多省并醌聚合物。通过红外光谱、热分析等方法表征改性聚合物的结构并研究了改性聚合物的介电性能。研究结果表明改性聚合物仍有较好的热稳定性,5%质量损失温度>387℃;20Hz下改性聚合物的最大介电常数值为100,比改性前低。同时合成了乙醇可溶的改性多省并醌聚合物,20Hz下最大介电常数为19997。     

块状PMMA/TiO_2有机-无机杂化材料的制备与表征

以钛酸丁酯为前驱体,在亚化学计量的水中水解,以硅烷偶联剂(MPMS)和丙烯酸为改性剂,采用溶胶-凝胶法制得均一、稳定的淡黄色二氧化钛溶胶,透射电镜分析粒径约20～30nm;在溶胶中加入甲基丙烯酸甲酯(MMA)和偶氮二异丁腈(AIBN),采用热固化方法制得淡黄色透明的PMMA/TiO2块体材料;通过TEM、FT-IR、DSC和TG表征杂化材料的微观结构和热性能.研究表明,杂化材料中PMMA和TiO2是以共价键连接的,TiO2均匀分散在PMMA中,两相之间没有明显的相分离现象;当w(TiO2)=20%时,杂化材料的玻璃化转变温度为175℃,比纯PMMA提高了约70℃,分解温度为300℃,比纯PMMA提高了120℃.     

有机酸阴离子/LDH复合材料的插层组装条件及热稳定性研究

以Mg/Al-CO_3-LDH为前体,采用离子交换法制备了脂肪酸(丁二酸、己二酸、癸二酸、酒石酸)和芳香酸(笨甲酸、水杨酸)柱撑水滑石复合材料,并利用XRD、FT-IR、TG和DTA技术对样品进行了结构表征和性能测试.结果表明,通过控制离子交换条件,6种有机酸根离子可以插入水滑石的层间完全取代CO_3~(2-),形成具有超分子结构稳定的有机酸阴离子/LDHs复合材料.     

Synthesis and characterization of an energetic three-dimensional metal–organic framework with blue photoluminescence

A new inorganic–organic hybrid lead(II) coordination polymer [PbCl(tza)]_n (Htza = tetrazole-1-acetic acid) has been synthesized under hydrothermal condition. The complex was characterized by elemental analysis, FT-IR spectroscopy, single-crystal X-ray analysis, thermogravimetric analysis (TG) and differential scanning calorimetry thermal analysis (DSC). The Pb(II) centers are connected through both the tza and Cl^? bridging ligands to form a three-dimensional metal–organic framework (MOF). The compound has been found to exhibit blue photoluminescence in the solid state at room temperature and may be good candidates for photoactive materials. DSC thermal analysis shows the complex is an energetic coordination compound and tza can be used as an energetic ligand.     

羧基遥爪热致性主链液晶离聚物的合成与表征

以对羟基苯甲酸甲酯和1,4-丁二醇为主要原料,经熔融酯交换合成介晶基元双(对羟基苯甲酸)丁二醇酯(BBHB);以四氯乙烷为溶剂,采用溶液缩聚法将BBHB与适量的对苯二甲酰氯(TPC)反应,经Na2CO3溶液处理,合成端基为羧基的液晶离聚物。通过红外光谱等分析对它们的化学结构进行了表征。表明:所合成的液晶离聚物P1~P3为纹影织构,属于典型的向列型液晶,液晶相区间为100℃左右,羧基对液晶区间和玻璃化转变温度(Tg)、熔融温度(Tm)、相转变温度(Tc)影响不大。     

Synthesis, characterization, thermolysis and performance evaluation studies on alkali metal salts of TABA and NTO

The lithium (Li) and potassium (K) salts of 3-nitro-1,2,4-triazol-5-one (NTO) and 2,4,6-trinitroanilino benzoic acid (TABA) were prepared and characterized during this work. The synthesis was carried out by addition of a solution of lithium/potassium hydroxide to the aqueous solution of NTO and TABA, respectively. The products were characterized by elemental analysis, metal content determination and Fourier Transform Infrared (FTIR) Spectrum. Differential scanning calorimetry (DSC) profile indicated that Li and K salts of NTO and TABA undergo exothermic decomposition in the temperature range of 257-360 degrees C suggesting their energetic nature. The thermo gravimetric (TG) weight loss pattern revealed loss of water for Li/K salts of NTO and TABA in the temperature range of 115-155 degrees C. Sensitivity results revealed that the compounds are insensitive to impact and friction (impact sensitivity--height of 50% explosion>170 cm and friction insensitivity up to 36 kg) stimuli despite even the parent molecule of NTO salts (NTO) being HEM in the hazard category of 1.1. The FTIR spectra of the gaseous products evolved during TGA of NTO and TABA salts indicated the release of NO2. The formation of products such as LiNCO and KNCO was also observed in case of NTO salts, whereas that of CO2 and NH containing products was indicated in case of TABA salts during this study. In order to assess the performance as energetic ballistic modifiers (EBMs), NTO and TABA salts were incorporated in the ammonium perchlorate-hydroxyl terminated polybutadiene (AP-HTPB) composite propellants. The potassium salts enhanced the burning rate of the propellant. The best catalytic effect was obtained with K-TABA salt, which increased the burning rate to the extent of approximately 81% as well as brought down the n-value to 0.15 (pressure 2-9 MPa).     

聚氨酯/聚丙烯酸酯复合乳液及其相容性

用N-甲基二乙醇胺、甲苯二异氰酸酯、聚异丙二醇等制得了水性的阳离子聚氨酯(PU),再和含丙烯酸等丙烯酸酯类混合单体聚合反应制得稳定的聚氨酯/聚丙烯酸酯(PUA)乳液。将PUA膜与PU的差谱覆盖在聚丙烯酸酯(PA)红外图谱上,在3408.57cm-1和1582.86cm-1处出现了新的峰,表明漆膜分子内形成了新的相互作用。DSC测得漆膜只有一个玻璃化转变温度,说明漆膜是共混相容的离聚物。比较了不同AA/MDEA摩尔(叔氨基和羧基)比值下的乳液粒径、黏度以及漆膜的各项力学性能,比值在0.8:1附近时,漆膜的热稳定性较好,各项力学性能均满足技术性能要求。     

Synthesis, characterization and properties of nitrogen-rich salts of trinitrophloroglucinol

Five different nitrogen-rich salts of trinitrophloroglucinol (H(3)TNPG) have been prepared by the reaction of ammonia, aminoguanidine (AG), carbohydrazide (CHZ), semicarbazide (SCZ) and 5-aminotetrazo (ATZ) with trinitrophloroglucinol in aqueous solution through the heating method of water bath, with the yield up to 80%. These salts were characterized by elemental analysis, FT-IR, DSC and TG-DTG techniques. Their melting temperature is consistent with the thermal decomposition temperature. Their thermal decomposition process and kinetic parameters from 323 to 673K were investigated under a linear heating rate by DSC. The thermal decomposition of these salts undergoes an intensive exothermic decomposition stage to evolve abundant gas products and the enthalpies of exothermic decomposition reaction are high. The tests of sensitivity properties show these salts are insensitivity. All the properties of five nitrogen-rich salts appeared to depend on molecule structures and interconnection. It can be concluded that the five compounds are worthy of further in-depth studies as the gas-generating composition, emission reagents and propellants.     

癸酸-棕榈酸-硬脂酸/膨胀石墨蓄能复合相变材料的制备与热性能研究

癸酸、棕榈酸、硬脂酸形成的三元低共熔物与膨胀石墨通过真空浸渍法制备出新型癸酸-棕榈酸-硬脂酸/膨胀石墨储能复合相变材料,适宜的质量比为m(癸酸)∶m(棕榈酸)∶m(硬脂酸)=77.0∶11.5∶11.5,m(癸酸-棕榈酸-硬脂酸)∶m(膨胀石墨)=13∶1。采用DSC、FT-IR、TG、SEM、冷热循环实验和蓄/放热实验研究了材料的结构和热性能。SEM和FT-IR分析结果表明低共熔物与膨胀石墨是通过物理吸附方式结合。DSC结果表明复合材料融化和凝固时的相变温度为28.93℃和16.32℃,相变潜热为137.38J/g和141.51J/g。TG结果表明复合相变材料在100℃以下具有良好的热稳定性。500次热循环和蓄/放热实验表明循环前后复合相变材料的热可靠性好,且使用寿命长。膨胀石墨的添加改善了复合材料的热性能和热导率。研究表明制备的新型复合相变材料具有合适的相变温度、较高的相变潜热和热导率,热性能稳定可靠,可用于低温蓄能领域。