Hexacyanoferrate as the Electrochemical Probe for 2-Mercaptobenzothiazole Modified Gold Electrode

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｒａｔｅｏｆｅｌｅｃｔｒｏｎｔｒａｎｓｆｅｒｉｓｍｕｃｈａｆｅｃｔｅｄｂｙｓｅｖｅｒａｌｆａｃｔｏｒｓ，ｓｕｃｈａｓｅｌｅｃｔｒｏｄｅｍａｔｅｒｉａｌ，ｅｌｅｃｔｒｏｄｅｆａｂｒｉｃａｔｉｏｎｔｅｃｈｎｉｑｕｅｓ，ｐｏｌ...     

Selective Reduction of α,β-Unsaturated Amides with NaBH_4/BiCl_3 System

ＳｅｌｅｃｔｉｖｅＲｅｄｕｃｔｉｏｎｏｆα，β－ＵｎｓａｔｕｒａｔｅｄＡｍｉｄｅｓｗｉｔｈＮａＢＨ_４／ＢｉＣｌ_３ＳｙｓｔｅｍＳｅｌｅｃｔｉｖｅＲｅｄｕｃｔｉｏｎｏｆα，β－ＵｎｓａｔｕｒａｔｅｄＡｍｉｄｅｓｗｉｔｈＮａＢＨ_４／ＢｉＣｌ_３Ｓｙｓｔｅ...     

Cleavage of Nucleotides by Lanthanide Metal Complexes

ＩｎｔｒｏｄｕｃｔｉｏｎＳｙｎｔｈｅｔｉｃｎｕｃｌｅａｓｅｓｗｈｉｃｈｅｆｉｃｉｅｎｔｌｙａｎｄｓｅｌｅｃｔｉｖｅｌｙｍａｋｅｎｕｃｌｅｉｃａｃｉｄｓｃｌｅａｖｅｄｕｎｄｅｒｍｉｌｄｃｏｎｄｉｔｉｏｎｓｈａｖｅｍａｎｙｉｍｐｏｒｔａｎｔｐｏｔｅｎｔｉ...     

Bright Red Organic Electroluminescent Devices Based on a Soluble Rare Earth Complex Eu(TTA)_3 Phen

ＩｎｔｒｏｄｕｃｔｉｏｎＯｒｇａｎｉｃｅｌｅｃｔｒｏｌｕｍｉｎｅｓｃｅｎｔ（ＥＬ）ｄｅｖｉｃｅｓｈａｖｅｂｅｃｏｍｅｏｎｅｏｆｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｓｕｂ－ｊｅｃｔｓｂｅｃａｕｓｅｏｆｔｈｅｉｒｐｏｔｅｎｔｉａｌａｐｐｌｉｃａｔｉｏｎａｓｌ...     

The Regioselectivity of Friedel-Crafts Acylation of Anisole Using Microwave Modified ZnCl_2/HY Zeolite Catalysts

ＩｎｔｈｉｓｗｏｒｋａｃｙｌａｔｉｏｎｂｅｔｗｅｅｎａｎｉｓｏｌｅａｎｄａｃｅｔｙｌｃｈｌｏｒｉｄｅｏｖｅｒＺｎＣｌ２／ＨＹｃａｔａｌｙｓｔｓｗｉｔｈｈｉｇｈｒｅｇｉｏｓｅｌｅｃｔｉｖｉｔｙｗａｓｒｅｐｏｒｔｅｄ．Ｔｈｅｐａｒｔｉａｌｙｓｏｄｉｕｍｉ...     

Underpotential Deposition Study and Determination of Bismuth on Gold Electrode by Using Voltammetry

ＴｈｅｃｏｍｂｉｎａｔｉｏｎｏｆｓｔｒｉｐｐｉｎｇｖｏｌｔａｍｍｅｔｒｙｗｉｔｈＵＰＤｃａｎｌｅａｄｔｏｔｈｅｉｍｐｒｏｖｅｍｅｎｔｏｆｓｅｎｓｉｔｉｖｉｔｙ ,ｓｅｌｅｃｔｉｖｉ ｔｙａｎｄｒｅｖｅｒｓｉｂｉｌｉｔｙｆｏｒｅｌｅｃｔｒｏａｎａｌｙｔｉｃａｌｐｕｒｐｏｓｅａｎｄａｖｏｉｄｔｈｅｕｓｅｏｆｔｏｘｉｃｍｅｒｃｕｒｙａｓｔｈｅｗｏｒｋｅｌｅｃｔｒｏｄｅ1ａｎｄｔｈｅｎａｎａｌｙｔｉｃａｌａｐｐｌｉｃａｔｉｏｎｓｈａｖｅｂｅｅｎｄｅｓｃｒｉｂｅｄ .2 4 Ｉｎｔｈｉｓｗｏｒｋ ,ｗｅｄｅｖｅｌｏ…     

Syntheses and Characterizations of Novel One-dimensional Coordination Polymers Self-assembled from Co(NCS)_2 and Flexible Diester-bridged Pyridine-based Ligands

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｒｅｈａｓｂｅｅｎｒｅｃｅｎｔｒｅｓｅａｒｃｈｉｎｔｅｒｅｓｔｉｎｃｒｙｓｔａｌｅｎ ｇｉｎｅｅｒｉｎｇａｎｄｔｈｅｄｅｓｉｇｎｏｆｓｕｐｒａｍｏｌｅｃｕｌａｒａｒｃｈｉｔｅｃｔｕｒｅｓ .1Ｂｙｓｅｌｅｃｔｉｎｇｔｈｅｃｈｅｍｉｃａｌｓｔｒｕｃｔｕｒｅｏｆｌｉｇａｎｄｓａｎｄｔｈｅｃｏ ｏｒｄｉｎａｔｉｏｎｇｅｏｍｅｔｒｙｏｆｔｒａｎｓｉｔｉｏｎｍｅｔａｌｉｏｎｓ ,ｔｈｅｏｒｇａｎｉｃ/ｉｎｏｒｇａｎｉｃｈｙｂｒｉｄｍａｔｅｒｉａｌｓｍａｙｙｉｅｌｄａｓｅｒｉｅｓｏｆｎ…     

Synthesis and Crystal Structure of Ethoxyethyl 3-(2-chloro-5-pyridyl methylamino)-2-cyano-3-methylthio acrylate

１ＩＮＴＲＯＤＵＣＴＩＯＮＡｍｏｎｇｔｈｅｗｉｄｅｖａｒｉｅｔｙｏｆｐｈｏｔｏｓｙｓｔｅｍＩ（ＰＳＩ）ｐｈｏｔｏｓｙｎｔｈｅｔｉｃｅｌｅｃｔｒｏｎｔｒａｎｓ ｐｏｒｔｉｎｈｉｂｉｔｏｒｓ,ｔｈｅｈｉｇｈｌｙｐｏｔｅｎｔｃｙａｎｏａｃｒｙｌａｔｅＰＳＩ...     

The Reaction of Octacarbonyldicobalt and Dipropargyl Malonate

1　ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｃｈｅｍｉｓｔｒｙｏｆａｌｋｙｎｅｓｃｏｏｒｄｉｎａｔｅｄｔｏｃｏｂａｌｔｐｒｏｖｉｄｅｄａｖｅｒｙｄｙｎａｍｉｃｄｅｖｅｌｏｐｍｅｎｔｉｎｒｅｃｅｎｔｙｅａｒｓ[1～ 5] .Ｔｈｅｍａｉｎｄｒｉｖｉｎｇｆｏｒｃｅｏｆｔｈｉｓｒｅｓｅａｒｃｈａｃｔｉｖｉｔｙｈａｓｂｅｅｎｔｈｅａｂｉｌｉｔｙｏｆａｌｋｙｎｅｓｃｏｏｒｄｉｎａｔｅｄｔｏｃｏｂａｌｔｃａｒｂｏｎｙｌｏｒｃｙｃｌｏｐｅｎｔａｄｉｅｎｙｌｃｏｍｐｌｅｘｅｓｏｆｇｉｖｉｎｇｈｉｇｈｌｙｒｅｇｉｏｓｅｌｅｃｔｉｖ…     

Probing interaction of melittin with lipid membranes using liquid secondary ion mass spectrometry

Ｔｈｅｐｒｏｃｅｓｓｏｆｍｅｍｂｒａｎｅｉｎｓｅｒｔｉｏｎｏｆｔｈｅｔｏｘｉｃｐｒｏｔｅｉｎｃａｎｂｅｄｉｖｉｄｅｄｉｎｔｏｔｗｏｓｔｅｐｓ:ａｂｓｏｒｐｔｉｏｎａｎｄｉｎｓｅｒｔｉｏｎ.Ｔｈｅｐｒｏｔｅｉｎｍｏｌｅｃｕｌｅｓｆｉｒｓｔｉｎｔｅｒａｃｔｗｉｔｈｔｈｅｍｅｍｂｒａｎｅｓｕｒｆａｃｅａｎｄｂｅｃｏｍｅａｄｓｏｒｂｅｄｏｎｔｏｔｈｅｍｅｍｂｒａｎｅｔｈｒｏｕｇｈｓｔａｔｉｃｅｌｅｃｔｒｉｃｉｔｙ.Ｔｈｅｃｏｎｆｏｒｍａｔｉｏｎｏｆｔｈｅｔｏｘｉｃｐｒｏｔｅｉｎｗｉｌｌｃｈａｎｇｅｕｎｄｅ…     

Investigation of aggregation in solvent extraction of lanthanides by acidic extractants (organo-phosphorus and naphthenic acid)

Three acidic extractants (Ⅰ) di(2-ethylhexyl) phosphoric acid (HDEHP),(Ⅱ) 2-ethylhexyl phos-phonic acid mono-2-ethylhexyl ester (KEHPEHE) and (Ⅲ) naphthenic acid were employed in preparing the samples for the characterization of the coordination structure of lanthanlde-extractant complexes and the physicochemical nature of aggregates formed in the organic diluent of the solvent extraction systems.Photo correlation spectroscopy (PCS) re-suits on the aggregates formed by the partially saponified HDEHP in n -heptane showed that the hydrodynamic radius of the aggregates was comparable to the molecular dimensions of HDEHP.The addition of 2-octanol into the diluent,by which the mixed solvent was formed,increased the dimensions of the corresponding aggregates.Aggregates formed from the ianthamde ions and HDEHP in the organic phase of the extraction systems were found very unstable.In the case of naphthenic acid,PCS data showed the formation of w/o microemulsion from the saponified naphthenic acid in the mix     

电化学聚合漆酚钴膜引发甲基丙烯酸甲酯（MMA）聚合的研究

利用电化学技术合成的聚合漆酚（EPU）与氯化钴的异丙醇溶液反应,得到电化学聚合漆酚钴配合物膜,经XPS光电子能谱、红外光谱、TG－DTA、动态机械热分析（DMTA）以及原子发射光谱（AES）等手段进行表征并确定其结构。由于每个钴离子与EPU分子中两个链节单元的羟基发生配位引进进一步交联。因此玻璃化转变温度和耐热性能均得到提高。实验表明,在常温下的Na2SO3水体系（pH值为7）中配合物膜能引发甲基丙烯酸甲酯（MMA）聚合。     

The Coordination Structure of the Extracted Cobalt(II) Complex with a Synergistic Mixture Containing Lix63 and Versatic10

In the present work, the cobalt(II ) synergist complex with isobutyric acid (HL^I ) and 5‐hydroxy‐4‐octanone oxime (HB^I ), which were the corresponding short‐chain analogs of active synergistic mixture of Versatic10 (HL ) and Lix63 (5,8‐diethyl‐7‐hydroxy‐6‐dodecanoneoxime, HB ), was prepared and studied by X‐ray single‐crystal diffraction. The crystal structure of the cobalt(II ) synergistic complex showed that the composition of the complex was Co(HB^I )₂(L^I )₂ with a cis‐form octahedron geometry structure. Both intra and intermolecular hydrogen bonding between the uncoordinated carbonyl oxygen atom of the deprotonated monodentate anionic ligand L^I and the hydrogen atom of the α‐hydroxy or the oxime hydroxyl group of HB^I were observed in the crystal lattice. In order to bridge the gap between the solid‐state structure of the cobalt(II ) synergist complex and the solution structure of the extracted cobalt(II ) complex with the actual synergistic mixture containing Versatic10 and Lix63 in the nonpolar organic phase, both the cobalt(II ) synergistic complex and the extracted cobalt(II ) complex were further investigated by Fourier transform infrared spectroscopy (FT‐IR ) and electrospray ionization mass spectrometry (ESI‐MS ). The results indicated that the extracted cobalt(II ) complex in the nonpolar organic phase might possess a similar coordination structure as that of the cobalt(II ) synergist complex.     

Bis(mercaptoimidazolyl)(pyrazolyl)hydroborato complexes of zinc, cadmium, and cobalt: structural evidence for the enhanced tendency of zinc in biological systems to adopt tetrahedral M[S4] coordination

The bis(2-mercapto-1-methylimidazolyl)(pyrazolyl)hydroborato derivatives [pzBmMe]2Zn, [pzBmMe]2Co, and [pzBmMe]2Cd have been isolated and structurally characterized by X-ray diffraction. Despite their common [pzBmMe]2M composition, each of these complexes adopts a different structure. Thus, (i) the zinc complex exhibits a tetrahedral Zn[S4] structure in which only the sulfur donors coordinate to zinc, (ii) the cobalt complex exhibits a trigonal-bipyramidal Co[S3NH] structure in which one of the pyrazolyl groups and one of the B-H groups coordinate to cobalt, and (iii) the cadmium complex exhibits a six-coordinate Cd[S4H2] structure in which both B-H groups interact with the cadmium center. These comparisons emphasize that zinc has a greater preference for tetrahedral M[S4] coordination than does either cobalt or cadmium, an observation that is in accord with the prevalent role of zinc in the structural sites of enzymes.     

Crystal Structure,Thermal Decomposition Behaviors and Sensitivity Properties of a Novel Energetic Compound [Co(DAT)6](ClO4)2

A novel energetic coordination compound [Co(DAT)₆](ClO₄)₂ has been synthesized by using 1,5‐diaminotetrazole (DAT) as a ligand and its structure has been characterized using X‐ray single crystal diffraction, elemental analysis and FT‐IR spectroscopy. The central cobalt(II) cation is coordinated by six N atoms from six DAT molecules to form a six‐coordinated and distorted octahedral structure. Di‐dimension layer structure was formed by the extensive intermolecular hydrogen bonds between DAT ligands and ClO^?₄ anions along a‐axis and b‐axis. Thermal decomposition mechanism of [Co(DAT)₆](ClO₄)₂ was investigated based on differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Fourier transform infrared (FT‐IR) spectra. The kinetic parameters of the first exothermic process were studied by applying the Kissinger's and Ozawa‐Doyle's methods. Additionally, the sensitivities of this complex were tested. The results of all the studies show that [Co(DAT)₆](ClO₄)₂ has an extreme potential application as an energetic material.     

Synthesis and characterization of tetrahedrally and octahedrally coordinated mixed-valence Co(II)/Co(III) complex with thiosemicarbazone-based ligand

Synthesis, characterization, and X-ray crystal structure for a mixed-valence binuclear Co(II)/Co(III) complex with the dianionic dithiolate form of a pentadentate ligand 2,6-diacetylpyridinebis(thiosemicarbazone) are reported. A new synthetic methodology has been employed replacing usual cobalt(II) salts by [Co(NH₃)₅Cl]Cl₂ as a precursor. The coordination geometry of cobalt(II), CoN₂S₂, was found to be distorted tetrahedral, whereas the cobalt(III) coordination sphere, CoN₄S₂, is slightly distorted octahedral. The magnetic behavior and molar conductivity of the complex are in agreement with the mixed-valence state.     

Exploring the reactivity of four-coordinate PNPCoX with access to three-coordinate spin triplet PNPCo

The compounds (PNP)CoX, where PNP is (tBu2PCH2SiMe2)2N- and X is Cl, I, N3, OAr, OSO2CF3 and N(H)Ar, are reported. Some of these show magnetic susceptibility, color, and 1H NMR evidence of being in equilibrium between a blue, tetrahedral S=3/2 state and a red, planar S=1/2 state; the equilibrium populations are influenced by subtle solvent effects (e.g., benzene and cyclohexane are different), as well as by temperature. Attempted oxidation to Co(III) with O2 occurs instead at phosphorus, giving [P(O)NP(O)]CoX species. The single O-atom transfer reagent PhI=O likewise oxidizes P. Even I2 oxidizes P to give the pendant phosphonium species (tBu2P(I)CH2SiMe2NSiMe2CH2PtBu2)CoI2 with a tetrahedral S=3/2 cobalt; the solid-state structure shows intermolecular PI...ICo interactions. Attempted alkyl metathesis of PNPCoX inevitably results in reduction, forming PNPCo, which is a spin triplet with planar T-shaped coordination geometry with no agostic interaction. Triplet PNPCo binds N2(weakly) and CO (whose low CO stretching frequency indicates strong PNP-->Co donor power), but not ethene or MeCCMe.     

Dual coordination modes of ethylene-linked NP2 ligands in cobalt(II) and nickel(II) iodides

Here we report the syntheses and crystal structures of a series of cobalt(II) and nickel(II) complexes derived from (R)NP2 ligands (where R = OMe(Bz), H(Bz), Br(Bz), Ph) bearing ethylene linkers between a single N and two P donors. The Co(II) complexes generally adopt a tetrahedral configuration of general formula [(NP2)Co(I)(2)], wherein the two phosphorus donors are bound to the metal center but the central N-donor remains unbound. We have found one case of structural isomerism within a single crystal structure. The Co(II) complex derived from (Bz)NP2 displays dual coordination modes: one in the tetrahedral complex [((Bz)NP2)Co(I)(2)]; and the other in a square pyramidal variant, [((Bz)NP2)Co(I)(2)]. In contrast, the Ni(II) complexes adopt a square planar geometry in which the P(Et)N(Et)P donors in the ligand backbone are coordinated to the metal center, resulting in cationic species of formula [((R)NP2)Ni(I)](+) with iodide as counterion. All Ni(II) complexes exhibit sharp (1)H and (31)P spectra in the diamagnetic region. The Co(II) complexes are high-spin (S = 3/2) in the solid state as determined by SQUID measurements from 4 to 300 K. Solution electron paramagnetic resonance (EPR) experiments reveal a high-spin/low-spin Co(II) equilibrium that is dependent on solvent and ligand substituent.     

Effect of temperature on the extraction of octahedral and tetrahedral cobalt(II) by 8-hydroxyquinoline and/or dibenzo-18-crown-6 or dibenzylamine

The extraction behavior of octahedral and tetrahedral cobalt(II) complexes from aqueous nitrate medium was studied in the system 8-hydroxyquinoline (HOX) and dibenzo-18-crown-6 (Db 18C6) or dibenzylamine (DBA) in chloroform at different temperatures to evaluate the thermodynamic functions as well as the equilibrium constants of each reaction. The stoichiometry of the extracted organic phase species were established to be Co(OX)₂·Db18C6 for the octahedral cobalt and Co(OX)₂·DBA for the tetrahedral cobalt.     

Optical spectroscopy study of organic-phase lanthanide complexes in the TALSPEAK separations process

Time-resolved fluorescence spectroscopy and Fourier transform IR spectroscopy have been applied to characterize the coordination environment of lipophilic complexes of Eu(3+) with bis(2-ethylhexyl)phosphoric acid (HDEHP) and (2-ethylhexyl)phosphonic acid mono(2-ethylhexyl) ester (HEH[EHP]) in 1,4-diisopropylbenzene (DIPB). The primary focus is on understanding the role of lactate (HL) in lanthanide partitioning into DIPB solutions of HDEHP or HEH[EHP] as it is employed in the TALSPEAK solvent extraction process for lanthanide separations from trivalent actinides. The broader purpose of this study is to characterize the changes that can occur in the coordination environment of lanthanide ions as metal-ion concentrations increase in nonpolar media. The optical spectroscopy studies reported here complement an earlier investigation of similar solutions using NMR spectroscopy and electrospray ionization mass spectrometry. Emission spectra of Eu(3+) complexes with HDEHP/HEH[EHP] demonstrate that, as long as the Eu(3+) concentration is maintained well below saturation of the organic extractant solution, the Eu(3+) coordination environment remains constant as both [HL](org) and [H(2)O](org) are increased. If the total organic-phase lanthanide concentration is increased (by extraction of moderate amounts of La(3+)), the (5)D(0) → (7)F(1) transition singlet splits into a doublet with a notable increase in the intensity of both (5)D(0) → (7)F(1) and (5)D(0) → (7)F(2) electronic transitions. The increased multiplicity in the emission spectra indicates that Eu(3+) ions are present in multiple coordination environments. The increased emission intensity of the 614 nm band implies an overall reduction in symmetry of the extracted Eu(3+) complex in the presence of macroscopic La(3+). Although [H(2)O](org) increases to above 1 M at high [HL](tot), this water is not associated with the Eu(3+) metal center. IR spectroscopy results confirm a direct Ln(3+)-lactate interaction at high concentrations of lanthanide and lactate in the extractant phase. At low organic-phase lanthanide concentrations, the predominant complex is almost certainly the well-known Ln(DEHP·HDEHP)(3). As lanthanide concentrations in the organic phase increase, mixed-ligand complexes with the general stoichiometry Ln(L)(n)(DEHP)(3-n) or Ln(L)(n)(DEHP·HDEHP)(3-n) become the dominant species.