Nitro-PAPS分光光度法测定葡萄糖酸锌

为建立一种快速、简便、灵敏分光光度法测定葡萄糖酸锌方法,在非离子型表面活性剂聚氧乙烯失水山梨醇油酸单脂(Tween-80)及聚氧乙烯异辛基苯基醚(TritonX-100)存在下,用水溶性试剂2-(5-硝基-2-吡啶偶氮)-5-[N-正丙基-N-(3-磺酸丙基)氨基]苯酚二钠(简称Nitro-PAPS)作显色剂直接光度法测定葡萄糖酸锌。结果表明,该法显色络合物最大吸收波长为580nm,本法线性范围为0~1μg/mL,表观摩尔吸光数为1.41×105L.mol-1.cm-1,回收率为98.5%~102.8%。该法具有操作快速、简便、结果灵敏可靠等优点,应用本法直接测定补锌口服液葡萄糖酸锌含量,结果满意。     

Synthesis and Characterization of Novel Orange-emitting Iridium（Ⅲ） Complexes with Diphenylquinoline Ligands Containing Fluorinated Substituent

Three new cyclometalated iridium（m） complexes based on ligands of diphenylquinoline with fluorinated subsfituents were prepared, and characterized by elemental analysis （EA）, ^1H NMR, and mass spectroscopy （MS）. The photophysical and electrophosphorescent properties of the complexes were briefly discussed.     

Synthesis and X-ray crystal structures of six [TeL4][MF6] salts, where L is ethylene- or trimethylene-thiourea, and M is Si, Ge or Sn. Five Te(II) complexes with a novel type of structure linked together by unusual N–HF hydrogen bonds

The complexes [Te(etu)₄][SiF₆] (1), [Te(etu)₄][SiF₆] · H₂O (2), [Te(trtu)₄][SiF₆] (3), [Te(etu)₄][GeF₆] · H₂O (4), [Te(trtu)₄][GeF₆] (5) and [Te(etu)₄][SnF₆] (6) (etu = ethylenethiourea, trtu = trimethylenethiourea) have been prepared and their crystal structures determined by X-ray crystallographic methods. The crystals of 1, 3 and 5 are tetragonal; space groups P4cc (No. 103) with Z = 4 for 1, P4nc (No. 104) with Z = 2 for 3, and I4 (No. 79) with Z = 2 for 5. The crystals of 2, 4 and 6 are orthorhombic, space group Pccn (No. 56) with Z = 8 for 2 and 4 and Z = 4 for 6; those of 2 and 4 being isomorphous. The cations contain square planar or slightly distorted square planar TeS₄ coordination groups. In 1, 3 and 5 the Te atoms are located on fourfold rotation axes; the cations have fourfold rotational symmetry and the four thiourea ligands extend to the same side of the TeS₄ plane. These are the first examples of [TeL₄]²⁺ conformers of this type. In 2 and 4 the Te atoms lie on general positions; the cations are distorted versions of those in 1, and also in these the four ligands extend to the same side of the TeS₄ plane. In 6 the Te atoms are located on twofold rotation axes, the conformation of the cations corresponds to the point group C₂ with two neighbouring ligands extending to one side of the coordination plane and the remaining two to the opposite side. In 1–5 each of the four ligands forms a N–HF bond to the same F atom in the counter ion. The crystals of 1–5 are red, and those of 6 are yellow. The red colour is attributed to interactions of Te and S lone electron pairs caused by ligand TeS₄/TeSC tilt angles markedly different from 90°.     

酯交换法合成碳酸二苯酯用氧化铅－氧化锌催化剂的研究

 制备了一种用于苯酚与碳酸二甲酯酯交换合成碳酸二苯酯的新型氧化铅－氧化锌多相催化剂．研究了制备方法、焙烧温度、不同母体和母体配比对催化剂催化性能的影响．应用XRD，TPR和原子吸收光谱对催化剂结构进行了表征，发现Pb3O4是主活性物相，ZnO为助催化剂，并以非晶态或微晶态存在于催化剂体系中．当焙烧温度为500℃，n（Pb）／n（Zn）≈2时，催化剂的活性最高，碳酸二苯酯产率可达45．6％．考察了催化剂的重复使用效果，并对失活原因进行了探讨．     

Conductance Study of the Binding of K+ by Dibenzo-pyridino-18-crown-6 and 1,10-N,N′-didecyl-diaza-18-crown-6 in Acetonitrile

The binding of K+ by dibenzo-pyridino-18-crown-6 (B2-py-18-C-6) and1,10-N,N-didecyl-diaza-18-crown-6 (22-DD) has been studiedconductometrically at 10, 15, 20 and 25 °C in acetonitrile. Thecomplexes formed were assumed to have 1 : 1 stoichiometry. The complexes ofK+ with 18-crown-6 (18-C-6) and dibenzo-18-crown-6 (B2-18-C-6) were alsostudied for comparison purposes. The stability constant, K, of a givencomplex and its molar conductance, c, were obtained by subjectingthe conductance data to a non-linear least-squares curve fitting procedure.The values of the enthalpy change, H, the entropy change, Sand the Gibbs free energy, G, associated with the formation of the 1: 1 complexes were derived and compared with relevant literature data. Thevalues of G at 25 °C indicate that the binding capacity of thefour macrocycles follows the order 18-C-6 > 22-DD > B2-18-C-6 >B2-py-18-C-6. The difference between the molar ionic conductance of the freeK+ cation and that of the bound cation, KL+, was estimated and the trend insuch differences correlates with the molecular size of the macrocycle, L.     

Adducts of Rh2[MTPA]4 with some phosphine chalcogenides: nature of binding and ligand exchange

Adducts of four phosphine chalcogenides with the chiral dirhodium complex ([Rh-Rh]) were investigated by variable-temperature 1H and 31P NMR spectroscopy in order to compare their properties as axial ligands. Whereas the selenide (1) and the sulfide (2) are strong ligands with electrostatic attraction and, in addition, a significant orbital (HOMO-LUMO) interaction, the phosphine oxide compounds (P=O) bind primarily via electrostatic attraction and are relatively weak donors. Moreover, the overall bond strength in these adducts depends on steric congestion around the P=O group.     

Equilibrium and NMR Studies of Noncovalent Interactions in Binary Systems: Uridine,Adenosine, Cytidine and Thymidine,and Adenosine (or Cytidine) 5′-Monophosphate in Aqueous Solution

The molecular complex formation reactions of uridine (Urd) with adenosine (Ado), cytidine (Cyd), thymidine (Thd), adenosine 5-monophosphate (AMP) and cytidine 5-monophosphate (CMP) have been studied at 20°C. It was found that the main positive noncovalent centers of ion–dipole and dipole–dipole type interactions are the protonated N(3) atoms of Urd, whereas the negative centers are the endocyclic atoms of the bases characterized by high electron density from the second molecule involved in the reaction. Moreover, NMR results indicate the occurrence of stacking in the complex (Urd)H(Cyd), whereas in the complex, (Urd)H₂(Thd), it is the only type of interaction. Deprotonation of the latter species brings about a change in the character of the reaction and ion–dipole interactions have been detected in the adduct, (Urd)H(Thd). Interestingly, no involvement of the phosphate groups in the formation of AMP and CMP adducts has been evidenced and the main centers of the reactions were found to be the N(7)and N(1) atoms of AMP, or the N(3) atoms of CMP and Urd. Moreover, in the Urd/CMP system the NMR results suggest stacking-type interactions.     

Structure of polynuclear palladium(ii) hydroxocomplexes formed upon alkaline hydrolysis of palladium(ii) chloride complexes

The structure of polynuclear Pd^II hydroxocomplexes (PHC) formed as a result of alkaline hydrolysis of Pd^II chloride complexes was studied by EXAFS, SAXS, and TEM methods. It is established that in aqueous solutions a hydroxocomplex particle is a filament curled into a ball containing about 100 Pd atoms. The filament consists of planar coordination squares of PdO₄ units linkedvia one or two oxygen bridges of different geometry. Aging of samples results in an increase in the number of single bridging ligands and a decrease in the diameter of particles. Interatomic distances around palladium atoms were determined.Translated fromIzvestiya Akademii Nauk. Seriya Khimlcheskaya, No. 10, pp. 1901–1905, October, 1995.