Synthesis and structure of functional spherosilicate building block molecules for materials synthesis

Cubic, trialkyl tin functionalized spherosilicates Si₈O₂₀(SnR₃)₈ (R = Me, ⁿBu) and the pentagonal prismatic tin-spherosilicate Si₁₀O₂₅(SnMe₃)₁₀ have been synthesized and characterized. Single crystal X-ray structures were obtained for Si₈O₂₀(SnMe₃)₈ (I), Si₈O₂₀(SnMe₃)₈ · 4H₂O (I · 4H₂O), and Si₁₀O₂₅(SnMe₃)₁₀ · 4H₂O (II). Structural metrics for the silicate cores observed in these structures were compared to other Si₈O₁₂ and Si₁₀O₂₅ cores reported in the CSD database. A pronounced tetragonal distortion of the Si₈O₂₀ cage leads to Si-O-Si bond angles that are considerably distorted in I · 4H₂O when compared to other analogous Si₈O₁₂ structures described in the literature. These octameric stannylated spherosilicates readily react with metal chlorides to produce mesocopically interesting metal oxide and hybrid materials. An illustration of this is found in the reaction of the octameric anhydrous tin compound I with titanocene dichloride to give the octatitanocene derivative Si₈O₂₀(Cp₂TiCl)₈ · 3CH₂Cl₂ (III). The single crystal structure of III is also described.     

亚磷酸二正丙酯的气相色谱法测定

采用气相色谱法分离和测定合成有机磷农药的中间体亚磷酸二正丙酯。试验结果表明,在 5％ OV－ 7/Chromosorb W－ AW DMCS（ 0.231～ 0.387 mm）的色谱柱上,亚磷酸二正丙酯与内标物联苯等之间具有较好的分离效果。并且,以联苯为内标物时,亚磷酸二正丙酯的质量校正因子相当稳定,fW. A=2.47± 0.09（α =0.05,n=5）。该法操作简便、快速,准确度和精密度较好,对同一试样的 5次平行独立测定的相对标准偏差（ RSD）为 1.57％;该法的标准加入回收率达 99.2％～ 101.9％。     

具有新颖结构的亚磷酸锌化合物的水热合成与表征

在水热体系中以二乙烯三胺为模板剂合成了结构新颖的亚磷酸锌化合物Zn(DETA)Zn₂(HPO₃)₃.单晶X射线衍射分析结果表明,该化合物属正交晶系,Cmca空间群,晶胞参数a=1.889 25(1)nm,b=1.001 04(5)nm,c=1.630 32(8)nm,β=90°,V=3.083 3(3)nm3,Z=4,DC=1.162 Mg.m^-3,最终因子R1[I>2σ(I)]=0.068 5,wR₂[I>2σ(I)]=0.160 5.该化合物的结构中含有{ZnO₄},{ZnO₂N₃}和{HPO₃}基本结构单元,其中{ZnO₄}和{HPO₃}通过桥氧原子共顶点相互交替连接形成具有4-,8-和12-元环的无限延伸的二维层.有趣的是,{ZnO₂N₃}结构单元以二聚体形式{ZnODETA}₂悬挂在12-元环孔道中,这种结构在亚磷酸锌中鲜有报道.     

抗氧剂168的质量控制分析及杂质鉴定

抗氧剂168的质量控制分析及杂质鉴定;抗氧剂168;二叔丁基苯酚;液相色谱-质谱联用;高效液相色谱;紫外-可见光谱     

手性亚膦（磷）酸联二萘酚（胺）酯配体的应用研究

本文综述了手性亚膦（磷）酸联二萘酚酯及手性亚膦（磷）酸联二萘酚胺酯配体在不对称催化应用中的最新进性。     

NMR study of ester-interchange reactions during melt mixing of poly(ethylene terephthalate)/poly(butylene terephthalate) blends

The occurrence of ester-interchange reactions during PET/PBT blend processing has been confirmed by ¹³C-NMR measurements. The limitations of the method for precise quantification of the extent of reaction between high molecular weight polyester blends have also been pointed out. Titanium alkoxide has been confirmed as an efficient catalyst, and, within experimental precision, the stabilizing effect of triphenyl phosphite addition has been demonstrated. © 1996 John Wiley & Sons, Inc.     

Preparation and characterization of aromatic polyamides based on ether-sulfone-dicarboxylic acids

Two ether-sulfone-dicarboxylic acids, 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenylene)dioxy]dibenzoic acid (Me- III ) and 4,4′-[sulfonylbis(1,4-phenylene)dioxy]-dibenzoic acid ( III ), were prepared by the fluorodisplacement of 4,4′-sulfonylbis(2,6-dimethylphenol) and 4,4′-sulfonyldiphenol with p-fluorobenzonitrile, and subsequent alkaline hydrolysis of intermediate dinitriles. Using triphenyl phosphite (TPP) and pyridine as condensing agents, aromatic polyamides containing ether and sulfone links were prepared by the direct polycondensation of the dicarboxylic acids with various aromatic diamines in the N-methyl-2-pyrrolidone (NMP) solution containing dissolved calcium chloride. The inherent viscosities of the resulting polymers were above 0.4 dL/g and up to 1.01 dL/g. Most of the polyamides were readily soluble in polar solvents such as NMP, N,N-dimethylacetamide (DMAc), N,N-dimethylformamide (DMF), and dimethyl sulfoxide (DMSO), and afforded tough and transparent films by solution-casting. Most of the polymers showed distinct glass transition on their differential scanning calorimetry (DSC) curves, and their glass transition temperatures (T_g) were recorded between 212–272°C. The methyl-substituted polyamides showed slightly higher T_gs than the corresponding unsubstituted ones. The results of the thermogravimetry analysis (TGA) revealed that all the polyamides showed no significant weight loss before 400°C, and the methyl-substituted polymers showed lower initial decomposition temperatures than the unsubstituted ones. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2421–2429, 1997     

Preparation and characterization of aromatic polyamides based on a bis(ether‐carboxylic acid) or a dietheramine extended from 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane

Thermoplastic and organic‐soluble aromatic polyamides containing both bulky triphenylethane units and flexible ether linkages were prepared directly from 1,1‐bis[4‐(4‐carboxyphenoxy)phenyl]‐1‐phenylethane ( III ) with various aromatic diamines or from 1,1‐bis[4‐(4‐aminophenoxy)phenyl]‐1‐phenylethane ( V ) with various aromatic dicarboxylic diacids via triphenyl phosphite and pyridine. These polyamides had inherent viscosities ranging from 0.71 to 1.77 dL/g. All the polymers easily were dissolved in aprotic polar solvents such as N‐methyl‐2‐pyrrolidone and N,N‐dimethylacetamide, and some even could be dissolved in less polar solvents such as tetrahydrofuran. The flexible and tough films cast from the polymer solutions possessed tensile strengths of 89 to 104 MPa. The polyamides were thermally stable up to 460°C in air or nitrogen. Glass‐transition temperatures of these polyamides were observed in a range of 179 to 268°C via differential scanning calorimetry or thermomechanical analysis. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 247–260, 2000     

Synthesis and property comparison of isomeric AB‐type homo‐ and copoly(etherimide)s

AB‐type homo‐ and copoly(etherimide)s were prepared by the polymerization of 3‐ and 4‐(3,4‐dicarboxyphenyloxy)aniline hydrochlorides ( 3A and 4A ) at 160 °C in dimethylacetamide in the presence of triethylamine and triphenyl phosphite. After the structures of the polymers were characterized, their solubilities, ultraviolet–visible (UV–vis) absorption behaviors, thermal properties, and crystallinities were measured, and these properties are discussed with respect to the structure of the homopolymers and the composition of the copolymers. Poly(etherimide) (PEI) derived from 3A [PEI( 3A )] was amorphous and soluble in chloroform on heating, whereas that derived from 4A [PEI( 4A )] was crystalline and insoluble in common organic solvents even on heating. In UV–vis absorption spectra, PEI( 4A ) showed a small bathochromic shift relative to N‐phenylphthalimide, but PEI(3A) did not. PEI(3A) revealed a glass‐transition temperature (T_g) at 195 °C, but no T_g was detectable for PEI( 4A ). All the measured physical properties of the copoly(etherimide)s showed a good dependence on their composition between PEI( 3A ) and PEI( 4A ). © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 402–410, 2000