Progress on phthalocyanine-conjugated Ag and Au nanoparticles: Synthesis,characterization, and photo-physicochemical properties

Phthalocyanine (Pc) complexes are an important class of dyes with numerous (e.g., biological, photophysical, and analytical) applications. Among the methods used to improve the properties of these complexes, one should mention the introduction of different substituents, variation of the central metal ion, ligand exchange, and conjugation to nanomaterials (e.g., carbon-based nanomaterials and metal nanoparticles (NPs)). This work briefly reviews Pc complex conjugation to Ag and Au NPs, highlights the different NP shapes, and discusses the diversity of conjugation approaches. Moreover, the use of UV–Vis spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy, atomic force microscopy, dynamic light scattering and Fourier transform infrared spectroscopy to characterize Pc-NP hybrids is summarized. The effect of conjugation on Pc photo-physicochemical properties (fluorescence, singlet oxygen generation, triplet state formation, and optical limiting behavior) is discussed, and future perspectives for the synthesis and applications of new hybrids are provided.     

A new stereoselective synthesis of 2-amino-4,5-dihydrothiophene-3-carbonitrile derivatives

A new stereoselective method for the synthesis of trans-isomers of 2-amino-4-aryl-5-benzoyl-4,5-dihydrothiophene-3-carbonitriles was proposed. The method involves base-catalyzed reactions of phenacyl thiocyanate with 3-(het)aryl-2-cyanoprop-2-enethioamides. (4R,5S/4S,5R)-2-Amino-5-benzoyl-4-(2-chlorophenyl)-4,5-ihydrothiophene-3-carbonitrile was structurally characterized by X-ray diffraction analysis. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1379–1383, July, 2007.     

Synthesis and electrochemical properties of spinel LiMn2O4 prepared by the rheological phase method

Pure-phase and well-crystallized spinel LiMn₂O₄ powders were successfully synthesized by a simple rheological phase method. The thermal behavior and structure properties of the powders prepared by the rheological phase method compared with the solid-state reaction were investigated by thermogravimetry, powder X-ray diffraction , scanning electron microscopy and transmission electron microscopy. According to the results of the electrochemical tests, it is obvious that the sample resulting from the rheological phase method shows higher discharge capacity and better cycling stability than one formed in the solid-state reaction. The cyclic voltammogram and columbic efficiency curves also confirm that the product by the rheological phase method has a good cycling performance due to its fine cubic spinel structure and morphology.     

Electroreductive polymerization of trans-[RuCl 2(vpy) 4] on Nd-Fe-B magnets: electrochemical impedance spectroscopy interpretation, Raman spectroscopy, X-ray photoelectron spectroscopy and scanning electron microscopy analysis

The electropolymerization of trans-[RuCl₂(vpy)₄] (vpy=4-vinylpyridine) monomer on Nd-Fe-B magnets was studied by electrochemical impedance spectroscopy (EIS). Impedance diagrams obtained during the polymerization process were used to monitor film formation. The EIS results gave insight into the electrochemical phenomena occurring at the magnet surface as the polymerization process progressed. The film structure and morphology were also studied by X-ray photoelectron spectroscopy, scanning electron microscopy and Raman spectroscopy. The Raman spectroscopy results showed that the polymerization takes place at the vinyl groups of the monomer and also that the redox polymer structure is very similar to that of the monomer. The ratio of the intensity of the XPS peaks for fluorine (from the electrolyte PF₆ ^–) and ruthenium present in the film showed that the polymer on Nd-Fe-B contained an equal proportion of Ru²⁺ and Ru³⁺, indicating that part of the film is positively charged, i.e. {[RuCl₂(vpy)₄]⁺} _n .     

植入用Co—Cr—Mo合金与Ti—6Al—4V合金的电偶腐蚀研究

组件式设计常被用地人工髋关节，钴络钼合金（Ｃｏ－Ｃｒ－Ｍｏ）与钛合金（Ｔｉ－６Ａｌ－４Ｖ）的压配最常用，本文应用电化学方法研究了静态条件下两种合金的电偶腐蚀行为，浸泡实验表明，钴络钼合金为阳极，但电偶电流与其维钝电流相近，并无明显加速度腐蚀效应，钛合金为阴极，受到保护，失重及金相观察结果显示，在４５天的浸泡实验周期内，未发现腐蚀痕迹，混合电位理论和电位处于两种合金的钝化电位区，电偶电流为合金的维钝     

Phenol methylation over CrPO4 and CrPO4?AlPO4 catalysts

The vapor-phase catalytic alkylation of phenol with methanol and dimethyl carbonate on a series of differently prepared CrPO₄ (Cr/P=1) and CrPO₄-AlPO₄ (CrAIP) catalysts, has been studied at different temperatures (473–673 K). The reaction is first order in phenol, giving a mixture of O- and C-alkylated products (C-alkylation taking place preferentially at theortho-position). Moreover, dimethyl carbonate is a better methylating agent than methanol.     

Monolayers of hydrogen-bonded polymer blends at the air–water interface: poly(vinylacetate)+poly (4-hydroxystyrene)

 The surface pressure (Π) vs surface concentration (Γ_s) curves of the hydrogen-bonded polymer blend poly(vinylacetate)+ poly(4-hydro-xystyrene) (PVAc+P4HS) have been measured at 25 °C onto a water subphase at pH=2.0. While PVAc forms extended monolayers, and the free surface of water is found to be a good solvent for it, P4HS forms compressed monolayers, and the surface is a near Θ-type solvent for it. PVAc and P4HS form miscible non-ideal monolayers until near the collapse pressure through the whole concentration range. The composition dependence of the Π–Γ_s curves is rather complex. Contrary to what might be expected, the addition of PVAc to the blend does not reduce the rigidity of the monolayer until its weight fraction is larger than 0.5. The compressibility data of the P4HS-rich monolayers suggest the existence of a second maximum at high surface coverages, a result already observed in some polysiloxanes. Received: 11 March 1998 Accepted: 7 May 1998     

手性配体的空间结构与产物对映选择性的关系

首次采用4－烷氧羰基噻唑烷、E唑烷作为手性配体，诱导烷基锌对醛类的亲核加成反应，获得产物是烷基化的醛，最高达90％ee，产率98％的（S）－二级醇。系统地考察了该类手性配体三维空间结构变化与产物对映选择性的关系，当配体4－位烷氧羰基上的R、2－位R′基和环体上原子X发生变化时都会引起产物（S）－二 级醇的对映选择性发生规律性变化。对五种不同结构的底物醛在同一手性配体催化下，诱导烷基锌对醛类的亲核加成反应，底物结构变化也会引起（S）－二级醇对映选择性变化。     

手性5-l-(艹孟)氧基丁内酯并[3,4-d]-3-取代基-异(口恶)唑啉类化合物的合成

研究了手性元5-(R)-(l-(艹孟)氧基)-2(5H)-呋喃酮与取代苯甲醛肟以次氯酸钙作为氧化剂进行的区域选择性原位1,3-偶极环加成反应,同步生成两个新的手性中心,得到了一系列光学纯丁内酯并[3,4-d]-3-取代基-异(口恶)唑啉类化合物;应用波谱学手段及X射线单晶衍射法确证了产物的绝对构型,并对产物的核磁共振氢谱规律性加以总结.     

Metathesis of hex-1-ene in ionic liquids catalyzed by WCl6

Metathesis of hex-1-ene in ionic liquids catalyzed by WCl₆ was studied. The metathesis is preceded by isomerization of hex-1-ene to hex-2-ene, from which the main reaction product, viz., oct-4-ene, is derived. The WCl₆-1-butyl-3-methylimidazolium tetrafluoroborate (BMIM·BF₄) system efficiently catalyzes metathesis of linear olefin, the ionic liquid serving as the reaction medium by forming a stable homogeneous catalytic system with WCl₆. The yields of the metathesis products increase with increasing reaction temperature. The addition of tin-containing promoters leads to a substantial increase in the reaction rate. In the WCl₆-BMIM·BF₄-SnBu₄ system, the selectivity of the formation of oct-4-ene is significantly enhanced.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2094–2097, October, 2004.