Synthesis of Sulfur-Containing Bis-Terpenoids Based on Monoterpene Oxides

Ethanedithiol and di(mercaptoethyl)sulfide react regio- and stereoselectively with (+)-3-carene and -hydroxy(-)--pinene -oxides in the presence of sodium ethoxide to give the corresponding bis- and tris-sulfides with two terpene fragments     

Crystallization behavior and biodegradation of poly(3-hydroxybutyrate) and poly(ethylene glycol) multiblock copolymers

Block copolymerization by using isocyanates is an effective method for incorporating PHB and PEG because it can prepare copolymers with good properties, such as toughness, strength, and so on. In this study, we adopted soil suspension system to estimate the biodegradability of a series of PHB/PEG multiblock copolymers with different compositions and block lengths. In the degradation process, the changes in weight loss, molecular weight, and tensile strength were periodically measured to determine the biodegradability, and the surface morphology was also observed by SEM. In contrast to pure PHB, the weight loss of the copolymer was relatively lower. On the other hand, the tensile strength and molecular weight experienced apparent decrease, and for BHG1000-3-1, they reached 46.7% and 77.7% of the initial value, respectively. SEM observation showed that the surface was covered with numerous erosion pits. All these indicate that the degradation indeed took place and long-chain molecules have been hydrolyzed into shorter ones. The crystallization behavior was also investigated by DSC and WAXD. The results showed that both the segments, PEG and PHB, can form crystalline phases at lower PHB contents ranging from 29% to 44%, and when PHB component was more than 60%, only PHB phase can crystallize.     

PEO-LiClO_4-ZSM5 composite polymer electrolyte (IV): Polarized optical microscopy study

All solid-state lithium polymer batteries may be one of the best choices for the future electrochemical power source, characterized by high energy densities, good cyclability, reliability and safety[1,2]. Owing to its potential capability to replace the t…     

ZrxTixAl1-2xO2的制备及其在三效催化剂上的应用

Zr_0.5Ti_0.5O₂(ZT) and Zr_0.25Ti_0.25Al_0.5O₂(ZTA) mixed oxides were prepared by co-precipitation method and characterized by low temperature adsorption-desorption， XRD and NH₃-TPD. The activity of Pt/Zr_0.5Ti_0.5O₂ and Pt/ Zr_0.5Ti_0.5Al_0.5O₂ catalysts was evaluated using the simulated gases. The results show that ZTA samples exhibit higher specific surface area， larger pore volume and proper surface acidic amount and acidity in comparison with ZT. The results of the catalytic test indicate that Pt/ZT and Pt/ZTA catalysts exhibit excellent low-temperature catalytic activity and lower light-off temperatures of hydrocarbon， carbon monoxide and nitrogen oxides， especially better conversion for nitrogen oxides (NO_x). The addition of Al₂O₃ into ZT enhanced the anti-aging property of Pt/ ZTA catalysts due to the excellent textural， structural， surface acidity and thermal stability.     

Syntheses, crystal structures and magnetic properties of a new nitronyl nitroxide NIT2-bithph and its manganese(II) compound [Mn(hfac)2(IMHBithph)]2·(NIT2-bithph)(C6H14)

A new nitronyl nitroxide NIT2-bithph (1) and its manganese(II) compound [Mn(hfac)₂(IMHBithph)]₂·(NIT2-bithph)(C₆H₁₄) (2) (hfac = hexafluoroacetylacetonate; NIT2-bithph = 4,4,5,5-tetramethyl-2-(bithiophenal-2-yl)imidazoline-1-oxyl-3-oxide; IMHBithph = 1-hydroxy-2-bithiophenal-4,4,5,5-tetramethyl-4,5-dihydro- 1H-imidazole) have been synthesized and structurally characterized by X-ray diffraction methods. The units of compound 1 were connected as one-dimensional chain by the intermolecular hydrogen bonds which afford an intermolecular antiferromagnetic interaction between nitronyl nitroxide radicals within the chain (J = −1.89 cm⁻¹). Compound 2 resulting from the reaction of Mn(hfac)₂·2H₂O and NIT2-bithph is dinuclear and includes the reduced amidino-oxide form of NIT2-bithph, it is made up of three parts: a [Mn(hfac)₂(IMHBithph)]₂ dimer unit, an uncoordinated NIT2-bithph radical and a noncoordinated solvent molecule of hexane, the molecule of radical is hydrogen bonded to its reduced form. Two reduced IMHBithph ligands bridge the two manganese(II) ions through their amidino-oxide oxygen atoms resulting in a small intramolecular antiferromagnetic interaction between the manganese ions (J = −1.55 cm⁻¹).     

(R)-2-羟基-4-苯基丁酸乙酯的合成

综述了血管紧张素转化酶抑制剂类治疗高血压和充血性心力衰竭药物的关键中间体（R）－2－羟基－4－苯基丁酸乙酯的合成方法。参考文献25篇。     

Cobalt(II) and nickel(II) complexes of a cyclam derivative as carriers in iodide-selective electrodes

The ligand 1,4,8-tri(n-octyl)-1,4,8,11-tetraazacyclotetradecane (L¹) containing pendant octyl groups has been synthesised. L¹ is a tetraazamacrocycle derived from the well-known cyclam unit, and the Ni²⁺ and Co²⁺ complexes, [Ni(L¹)]²⁺ and [Co(L¹)]²⁺, have been isolated and characterised. The ability of the nickel(II) and cobalt(II) complexes to act as anion receptors has been studied by using them as ionophores in membrane-based ion-selective electrodes (ISEs). The PVC membrane containing the complex [Ni(L¹)]²⁺ and 2-nitrophenyloctylether as plasticizer shows a Nernstian response against iodide in a concentration range from 1×10⁻¹ to 4×10⁻⁵ M I⁻ with a detection limit of 1.6×10⁻⁵ M I⁻ and a slope of 58.6 mV/pI⁻ at pH 7 (25 °C). In comparison, the electrode containing [Co(L¹)]²⁺ as ionophore gave a sub-Nernstian slope and a low lifetime. A comparison between the iodide-selective electrode containing [Ni(L¹)]²⁺ and other reported iodide-selective electrodes is also reported.     

聚乙二醇在高真空条件下的单链弹性

在过去二十年间，高分子的单链弹性已经得到了广泛的研究.然而由于环境和高分子之间往往有着复杂的相互作用，实验中很难得到高分子在严格无扰状态下的单链弹性（即本征弹性）.为此，利用单分子力谱技术研究了高真空条件下聚乙二醇（PEG）的单链弹性.结果表明，由于高真空条件下溶剂分子的干扰被消除，PEG在这一准无扰状态下呈现其本征弹性.在非极性有机溶剂中，由于溶剂分子和PEG之间只有微弱的范德华力作用，PEG表现出和高真空中基本一致的弹性.然而，在不同环境中，力曲线的低力区（F<100 pN）存在着细微的差异.这一现象可归因于不同条件下基底与PEG链之间的吸附力不同.采用的高真空力谱可用于研究其他高分子单链在准无扰状态下的本征弹性.     

Molekülsruktur und abs. konfiguration von (+)-p-menthadien-(1,8)-on-(2)-rhodium(I)-h5-cyclopentadienid, (+)-(4S-Carvon) RhI(C5H5)

The title compound crystallizes in the orthorhombic space group P2₁2₁2₁ with 4 molecules in the unit cell (cell dimensions: a 9.778(2), b 10.639(2) and c 12.423(4) Å). The structure was solved by means of the heavy atom method. The rhodium atom is linked to both olefinic double bonds. The terpene carbonyl group does not participate in coordination to rhodium. Unlike the endocyclic olefinic group, which is approximately perpendicular to the coordination plane of rhodium, the exocyclic Cz.sbnd;C double bound shows a considerable deviation from this arrangement. The π-complexation of carvone with rhodium proceeds diastereospecifically. The absolute configuration of (+)-carvone is 4S in agreement with the assignment derived by indirect chemical correlation.     

Alternativ-Liganden. XXII. Rhodium(I)-Komplexe mit Donor/Akzeptor-Liganden des Typs Me2PCH2CH2SiXnMe3−(X = F,Cl, OMe)

Alternative Ligands. XXII. Rhodium(I) complexes with Donor/Acceptor Ligands of the Typs Me₂PCH₂CH₂SiX_nMe_3?n(X = F, Cl, OMe) Donor/acceptor ligand of the type Me₂PCH₂SiX_nMe_3?n react with [Rh(CO)₂Cl]₂ ( 1 ) to give the mononuclear complexes RhCl(CO)(PMe₂CH₂CH₂SiX_nMe_3?n)₂ ( 2-6 , Table 1) with planar geometry of the donor atoms, one exception being Me₂PCH₂CH₂CH₂SiCl₃, yielding the crystalline Rh^III-complex RhCl₂(CO)(PMe₂CH₂CH₂SiCl₂)(PMe₂CH₂CH₂SiCl₃) ( 7 ) by oxidative addition of one of the SiCl bonds to the Rh¹ precursor. Structures with Rh → Si interaction between the basic central atoms and the acceptor group SiX_nMe_3?n could be detected in the isolated products neither spectroscopically nor by X-ray diffraction of the two representatives RhCl(CO)(PMe₂CH₂CH₂SiF₃)₂ ( 2 ) and RhCl(CO)[PMe₂CH₂CH₂siF₃]₂ ( 2 ) and RhCl(CO) [PMe₂CH₂CH₂Si(OMe₃]₂ ( 6 ). The presence of such acid/base adducts in the reaction mixture is indicated for the more acidic acceptor groups SiX_nMe_3?n byv_co values near 1990cm^?1, (see Table 3). The complex RhCl(CO)PMe₃)(PMe₂CH₂CH₂SiF₃ ( 8 ) is obtained by the reaction of RhCl(CO)(PMe₃)₂ ( 9 ) with Me₂PCH₂SiF₃ and has been identified spectroscopically in a mixture with 2 and 9 .