2，6－双（1′－苯基－3′－甲基－5′－氧代－4′－甲酰吡唑）吡啶稀土配合物的合成与表征

在乙醇－水溶液中合成了１４种２，６－双（１′－苯基－３′－甲基－５＇－氧代－４＇－甲酰吡唑）吡啶稀土配合物。元素分析确定其化学组成为ＲＥ＿２Ｌ＿３·ｎＨ＿２Ｏ，并用紫外可见光谱、红外光谱、核磁共振谱、热分析、荧光光谱、摩尔电导等进行了表征。     

两亲嵌段共聚物聚乙二醇-聚谷氨酸苄酯纳米粒药物载体的合成研究

用磺酸酯法制备单端氨基聚乙二醇引发剂,引发谷氨酸苄酯羧酸酐开环聚合,生成可生物降解的两亲嵌段共聚物聚乙二醇﹣聚谷氨酸苄酯(PEG-PBLG),用IR,NMR和GPC表征了共聚物。用超微透析法制备PEG-PBLG聚合物纳米粒,荧光芘探针法测定纳米粒的临界聚集浓度(cac)。紫外分光光度计考察纳米粒对疏水性药物的增溶作用,PEG-PBLG可作为亚微粒药物输送系统的载体。     

Direct melting polycondensation and characterization of poly(ɛ-caprolactone-co-lactic acid)

A kind of biodegradable material, poly(ɛ-caprolactone-co-lactic acid) [P(CL-co-LA)] was synthesized via the direct melting polycondensation of lactic acid (LA) and ɛ-caprolactone (CL). The influences of the polycondensation time, and the catalyst type on the intrinsic viscosity of P(CL-co-LA) were also investigated. The results indicate that P(CL-co-dl-LA), with an intrinsic viscosity of 0.4733 dL/g, can be prepared by direct melting polycondensation with the molar ratio LA/CL = 3:7 at 180°C and 70 Pa for 12 h, using 0.5% (mass fraction) of SnCl₂ as the catalyst. Compared with lactide ring-opening polycondensation (ROP), the direct melting polycondensation of LA and CL is more practicable and simple. Translated from Journal of South China University of Technology, 2006, 34(7): 7–11 (in Chinese)     

Development of the FTIR properties of nano-structure silica gel doped with different rare earth elements,prepared by sol-gel route

Structural characteristics of pure silica gel (silica-xerogel, SiO₂) and silica gel doped with some rare earth elements (REEs) such as, praseodymium Pr³⁺, and Europium Eu³⁺, Erbium Er³⁺ and Holmium Ho³⁺ ions, with different concentrations ranging from 1 up to 6%, in the form of monolith materials were prepared by sol-gel technique, Using tetra-ethoxysilane as precursor materials, which are of particular interest for sol-gel integrated optics applications. Some structural features of sol-gel derived monolith are analyzed, namely the structure of nano-particle momolith samples, based on X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR). We show that the XRD spectra of α-crystobalite are obtained for the pure samples at 1100°C and even by doping with the four REEs ions.     

Manifestation of diamagnetic chemical shifts of proton NMR signals by an anisotropic shielding effect of nitrate anions

A remarkable upfield shift of the py_α protons of complexed 2,2′-bipyridine in [cis-Pd(bpy)(NO₃)₂] is observed which is considered to originate from the anisotropic influence of suitably positioned coordinated nitrate anions around the Pd(II) centre of the molecule. A typical complexation-induced downfield shift is observed for the NH₂ protons in [cis-Pd(en)(NO₃)₂] where ‘en’ stands for ethylenediamine.     

(R)-4-Menthenone in the synthesis of optically pure sex pheromone of the peach leafminer moth (Lyonetia clerkella)

The synthesis of (14S)-methyloctadec-1-ene, sex pheromone of the peach leafminer moth (Lyonetia clerkella), is described to demonstrate a new potential of the synthetic use of (R)-4-menthenone.     

Crystal and molecular structure of <Emphasis Type="Italic">tris</Emphasis>(<Emphasis Type="Italic">m</Emphasis>-chlorophenyl)phosphine selenide

The crystal and molecular structure of tris(m-chlorophenyl)phosphine selenide, C₁₈H₁₂Cl₃PSe (I), was investigated by X-ray diffraction (XRD) analysis. The trigonal rhombohedral structure of I (space group \(R\overline 3 c\), a = 14.110(2) Å, c = 32.360(4) Å, Z = 12) was solved by direct methods and refined by least squares in an anisotropic approximation (R = 0.029) for 1319 averaged measured reflections (CAD-4 automatic diffractometer, λCuK_α).     

A novel heterocyclic system — dihydro-2H-1,5,2,4-dioxadiazine. 2,4-Dimethyldihydro-2H-1,5,2,4-dioxadiazine hydrochloride: synthesis and NMR study

The first representative of a novel heterocyclic system, namely, 2,4-dimethyldihydro-2H-1,5,2,4-dioxadiazine hydrochloride, was synthesized.     

Re-Evaluation of the Activity Coefficients of Aqueous Hydrochloric Acid Solutions up to a Molality of 2.0 Using Two-Parameter Hückel and Pitzer Equations. Part I. Results at 25°C

Simple two-parameter Hückel and Pitzer equations were used for the calculation of the activity coefficients of aqueous hydrochloric acid at 25°C up to a molality of 2.0 mol-kg^–1. The data obtained by Harned and Ehlers^(12,13) from galvanic cells without liquid junction were used in the analysis and the parameters obtained were compared to those obtained from all reliable data presented in the literature for HCl at this temperature. A good agreement between the parameters was always observed. The activity coefficients obtained by the new equations were compared to those suggested by Robinson and Stokes,⁽⁸⁾ Hamer and Wu,⁽¹⁾ and Pitzer and Mayorga,⁽⁹⁾ and good agreement was also found. The data from the most important literature data sets for HCl were also predicted using the new activity coefficient equations, and the magnitude of the resulting errors was close to the precision of the measurements, the errors forming an almost random pattern for all data sets.     

Co(III)氮芥配合物的合成、表征及其抗肿瘤活性的初步评价

低氧条件下,钴(Ⅲ)的氮芥配合物具有合适的还原电位,就可能还原得到比较活泼的Ｃｏ(Ⅱ)配合物,在溶液中其活性配体很快被体内的小分子取代,释放出的活性配体可以杀死低氧区内外的癌细胞,因此筛选合适的钴配合物作为低氧选择性抗癌药物的研究很有意义。本文以双 (2 氯乙基)胺(简称ＢＣＡ)为活性配体,取代乙酰丙酮为辅助配体,合成一系列Ｃｏ(Ⅲ)配合物(下图)。初步评估结果表明,其中两个配合物具有一定的低氧选择性,配合物的还原电位对药物的低氧选择性影响很大,合适的还原范围可能比较窄。1　实验部分1.1　试剂与仪器按文献[1]的方法合成…