Helicate tris(aryl)carbinolates bearing pendant NR2 donors – a new family of supporting ligands for the synthesis of Sc3+ alkyl complexes

The reactions of aryllithium reagents o-LiC₆H₄CH₂NR₂ with (MeO)₂CO afford two new tris(aryl)carbinols bearing pendant-NR₂ donor groups in the side chain [o-R NCH C H ] COH [R = Me, R + R = (CH) ]. These alcohols feature helical chirality due to differently inclined aromatic fragments and are presented in a crystalline cell as two M and P enantiomers. Carbinol (R = Me) readily reacts with (Me3SiCH2)3Sc(THF)2 to give a scandium bis(alkyl) complex [(o-C₆H₄CH₂NMe₂)₃CO]Sc(CH₂SiMe₃)₂ featuring rigid binding of the alkoxy anion through a κ¹-O, κ²-N chelating coordination mode     

Synthesis of coumarins by Pt-catalyzed hydroarylation of propiolic acids with phenols

Synthesis of coumarins from phenols and propiolic acids was examined by using a Pt catalyst such as PtCl₂/AgOTf, K₂PtCl₄/AgOTf, and K₂PtCl₄/AgOAc. Propiolic acid reacted even with less reactive phenols in trifluoroacetic acid to give coumarins and dihydrocoumarins. In the case of substituted propiolic acids, phenylpropiolic acid and 2-octynoic acid, the reactions proceeded selectively to afford coumarins in good to high yields.     

Electrochemical characterization of poly(vinylidenefluoride)-zinc triflate gel polymer electrolyte and its application in solid-state zinc batteries

Gel polymer electrolyte (GPE) films comprising of poly(vinylidenefluoride), propylene carbonate, ethylene carbonate and zinc trifluoromethane sulfonate are prepared and characterized. The composition of GPE is optimized to contain minimum liquid components with a maximum specific conductivity of 3.94×10⁻³ S cm⁻¹ at (25±1) °C. A detailed investigation on the properties such as ionic conductivity, transport number, electrochemical stability window, reversibility of Zn/Zn²⁺ couple and Zn/gel electrolyte interfacial stability have been carried out. The ionic conductivity follows a VTF behaviour with an activation energy of about 0.0014 eV. Cationic transport number varies from 0.51 at 25 °C to 0.18 at 70 °C. Several cells have been assembled with GPE as the electrolyte, zinc as the anode, γ-MnO₂ as the cathode and their charge–discharge behaviour followed. Capacity values of 105, 82, 64 and 37 mAh/g of MnO₂ have been achieved at 10, 50, 100 and 200 μA/cm² discharge current densities, respectively. The discharge capacity values are almost constant for about 55 cycles for all values of current densities. Cyclic voltammetric study of MnO₂ electrode in Zn/GPE/MnO₂ cell clearly shows intercalation/deintercalation of Zn²⁺.     

Diversification of shotgun process

Three protocols for shotgun process are put forth in which simultaneous multi-fold reactions occur exclusively to each other. The first one involves simple combination of selective and non-selective reactions. Even if the simple protocol fails to give rise to the high selectivity, satisfactory outcome can be achieved by kinetic control or adjustment of functional groups.     

Fullerides: heterometallic superconductors with composition M<Subscript>2</Subscript>M′C<Subscript>60</Subscript> (M = K,Rb; M′ = Yb,Lu, Sc)

One- or two-step reactions of potassium and rubidium fullerides with composition M_k C₆₀ (M = K, Rb; k = 3—6) and K₆C₆₀ + m K mixtures (m = 1, 3) with anhydrous salts MCl₃ (M = La, Pr, Nd, Sm, Gd, Tb, Yb, Lu, Y, Sc) and YbI₂ in a toluene—THF medium afforded heterometallic fullerides M_3–nM_nC₆₀ (n = 1—3). Among these compounds, substituted fullerides with composition M₂MC₆₀ (M = Yb, Lu, Sc) display superconducting properties with critical temperatures of 14—20 K.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1623–1628, August, 2004.     

用钼酸盐和罗丹明B连续光度法测定铈和钪

聚乙烯醇存在下，铈或钪钼杂多酸与罗丹明Ｂ（ＲＢ）形成离子缔合物，最大吸收均位于５７０ｎｍ，摩尔吸光系数分别为１．１６×１０＾６和５．６２×１０＾５Ｌ．ｍｏｌ＾－１．ｃｍ＾－１，ｃｍ＾－１，０－１．２μｇ／２５ｍＬＣｅ和０－２．０μｇ／ｍＬＳｃ服从比耳定律，检测限１．５ｎｇ／ｍＬＣｅ（ｎ＝１０）和１．１ｎｇ／ｍＬＳｃ（ｎ＝９）。缔合物的摩尔比为Ｃｅ：ｍＯ：ＲＢ＝１：６：３和 Ｓｃ：Ｍｏ：ＲＢ＝１：１     

Effect of the composition of nickel-containing composites based on stabilised zirconia on catalytic activity in methane steam conversion

A study was carried out on the composition and nature of the stabilizing additive on the activity of nickel-containing composites based on zirconia in the methane steam conversion. The methane conversions were 91–99% on Ni/ZrO₂(Y, Sc, Ce) at 700–800 °C.     

核酸-8-羟基喹啉-钪(Ⅲ)体系的荧光特性及其分析应用

在ＰＨ ６．８～８．８的酸度范围内，小牛胸腺脱氧核糖核酸（ｃｔＤＮＡ），鱼精子脱氧核糖 核酸（ｆｓＤＮＡ）以及酵母核糖核酸（ｙＲＮＡ）分别与８－羟基喹啉（８－ＨＱＬ）和Ｓｃ（Ⅲ）形成的三元 体系受 ２６４～２７０ ｎｍ紫外光激发将发出 ４９０～４９６ ｎｍ的荧光。与 Ｓｃ（Ⅲ）和 ８－ＨＱＬ 二元络合 物相比，三元体系的荧光量子产率增大，荧光寿命增长，最大发射波长紫移约 １０ ｎｍ。６个合 成样品的分析结果表明，利用 Ｓｃ（Ⅲ）／８－ＨＱＬ能十分灵敏的测定脱氧核糖核酸。