Alternating copolymerization of cyclohexene oxide and carbon dioxide under cobalt porphyrin catalyst

Cobalt porphyrin complexes（TPPCo^ⅢX）（TPP = 5,10,15,20-tetraphenyl-porphyrin;X = halide） in combination with bis（triphenylphosphine） iminium chloride（PPNCl） were used for the copolymerization of cyclohexene oxide and CO₂. The highest turnover frequency of 67.2 h^-1 was achieved after 13 h at 20℃,and the obtained poly（1,2-cyclohexylene carbonate）（PCHC） showed number average molecular weight（M_n） of 10×10³.Though the obtained PCHC showed atactic structure,the m-centered tetrads content reached 58.1%at CO₂ pressure of 1.0 MPa,and decreased to 51.9%at CO₂ pressure of 6.0 MPa,indicating that it was inclined to form atactic polymer at high CO₂ pressure.     

Syntheses, electrochemical and spectroelectrochemical properties of novel ball-type and mononuclear Co(II) phthalocyanines substituted at the peripheral and non-peripheral positions with binaphthol groups

Mononuclear cobalt phthalocyanine (CoPc) substituted at the non-peripheral 8 and peripheral positions 9 with 1,1′-binaphthyl-8,8′-diol and ball-type dinuclear Co₂Pc₂ substituted at the non-peripheral 10 and peripheral 11 positions with the same substituent are reported. The complexes with 1,1′-binaphthol-bridges were prepared from the corresponding phthalonitriles 4-7. The effects of the position of substituent on spectral, electrochemical and spectroelectrochemical properties of these complexes were also explored. The mononuclear complexes 8 and 9 exhibited one metal reduction, one ring reduction and one ring oxidation. The redox properties of the ball-type complexes 10 and 11 exhibited two reduction processes assigned to [(Co^IPc⁻²)₂]²⁻/[(Co^IPc⁻³)₂]⁴⁻ (I), (Co^IIPc⁻²)₂/[(Co^IPc⁻²)₂]²⁻ (II) and one oxidation process assigned to [(Co^IIIPc⁻²)₂]²⁺/Co^IIPc⁻²)₂ (III). The ball-type complexes are much easier to oxidize and more difficult to reduce than the corresponding monomers 8 and 9.     

Ni-Co双金属催化剂上沼气重整制氢机理

用传统湿式浸渍法制备了La₂O₃掺杂的商业γ-Al₂O₃负载的沼气重整催化剂Ni-Co/La₂O₃-γ-Al₂O₃, 并用程序升温加氢(TPH)、程序升温氧化(TPO)、程序升温表面反应(TPSR)、程序升温脱附(TPD)及脉冲实验对催化剂进行了表征. 结果表明, 沼气重整过程中Ni-Co/La₂O₃-γ-Al₂O₃催化剂上的表面碳物种主要来源于CH₄的裂解, CO₂的贡献很小. CH₄裂解能够产生三种活性不同的碳物种, 即C_α、C_β与C_γ. 随着反应的进行, C_α物种减小而C_β与C_γ物种增加, 且C_γ物种能够转变为惰性的石墨碳. 重整反应过程中CH₄与CO₂的活化能相互促进. 催化剂表面的O物种与C反应生成CO或与CH_x反应生成CH_xO再分解为CO与吸附态的H物种, 可能是Ni-Co/La₂O₃-γ-Al₂O₃催化剂上沼气重整的速率控制步骤.     

NHPI结合磺化酞菁钴催化的乙苯氧化反应

探索了一种由N-羟基邻苯二甲酰亚胺（NHPI）和磺化酞菁钴（CoSPc）组成的催化体系催化的将乙苯转化成相应氧化物有效且温和的方法．结果显示控制NHPI和乙苯物质的量比为0．050,NHPI和CoSPc物质的量比为6,反应温度90℃,是该氧化反应的最佳条件,在此条件下,乙苯在氧气中反应10h,乙苯转化率和苯乙酮选择性分...     

用1-亚硝基-2-萘酚修饰的微晶蒽分离富集与测定环境水中钴

建立了微晶蒽分离富集环境水样中痕量Co(II)的方法。在pH3.0条件下,1-亚硝基-2-萘酚与Co(II)形成红棕色螯合物被微晶蒽定量吸附,能使Co(II)与Pb(II)、Ni(II)、Mn(II)、Cu(II)、Cd(II)、Zn(II)、Fe(III)、Cr(III)、Al(III)等常见离子分离。本法富集倍数达100倍,检出限为0.14μg/L,回收率97.5%～105%,已应用于不同水样中Co(II)的测定。     

Nanomolar Determination of Penicillamine by Using a Novel Cobalt/Polyaniline/Carbon Paste Nanocomposite Electrode

The fabrication of cobalt/polyaniline nanocomposite was performed using a simple chemical method. It was characterized by using TEM and FTIR techniques. The nanocomposite was applied as a modifier in a carbon paste electrode for selective determination of penicillamine. Penicillamine reacts with emeraldine polyaniline by using 1,4, Michael addition reaction. It can decrease the voltammetric peak current of emeraldine polyaniline. The effects of pH and potential sweep rate on the response of the electrode were investigated. Differential pulse voltammetry was applied for quantitative determination. Dynamic linear ranges were obtained in the ranges of 1.0×10^?8–1.0×10^?7 mol L^?1 and 1.0×10^?9–1.0×10^?8 mol L^?1.     

Syntheses and molecular structures of new ferrocenylacetylide-bridged binuclear cobalt carbonyl cluster compounds

The reaction of ferrocenylacetylide compounds with Co₂(CO)₈ at room temperature affords four complexes bearing ferrocenyl units with approximately tetrahedral (μ-alkyne)dicobalt moieties [R–(C≡C) _n –R′] [Co₂(CO)₆] _{n ′} [R?=?C₅H₅FeC₅H₄-C(CH₃)₂-C₅H₄FeC₅H₄, R′?=?H, n?=?1, n′?=?1 (1); R?=?C₅H₅FeC₅H₄ [ferrocenyl (Fc)], R′?=?–CH=CHCl, n?=?1, n′?=?1 (2); R?=?Fc, R′?=?Fc, n?=?2, n′?=?1 (3), n′?=?2 (4)]. The compounds were characterized by elemental analysis, IR, ¹H(¹³C) NMR, MS and single-crystal X-ray diffraction analysis. The X-ray analyses show that coordination of the carbon–carbon triple bond and the dicobalt unit result in the formation of a Co₂C₂ tetrahedral core, and the substituents on the acetylenic units show a distortion from linearity that reflects this coordination mode.     

Large 1,3,5-triazine-based ligands coordinating transition metal ions: syntheses and structures of the ligands and the ball shaped nanometer-scaled Co complex [Co(2,4-R-6-R′-1,3,5-triazine)2](Br1.7(OH)0.3) · 4.8H2O {R = bis(2-diphenylmethylene) hydrazinyl; R′ = piperidin-1-yl}

Two new, large 1,3,5-triazine-based ligands with only N-donor functions were synthesized as well as the Co(II) salt [Co(DHPTBenz)₂](Br_1.7(OH)_0.3) · 4.8H₂O (DHPTBenz = 2,4-bis-(2-diphenylmethylene)-hydrazinyl-6-piperidin-1-yl-1,3,5-triazine). Single crystal X-ray structures of the Co(II) complex, DHPTBenz, and 2,4-dichloro-6-(piperidin-1-yl)-1,3,5-triazine (DCPT) have been determined. The last compound was used as starting material for the tridentate DHPTBenz ligand. Spectroscopic data of the ligand and the starting materials are reported. The Co(II) ion in the complex is distorted octahedrally coordinated by six N atoms of two DHPTBenz ligands. One N atom of the triazine ring of each ligand bonds axially with short distances of 1.953(3) Å and 1.954(3) Å, respectively, whereas two of the hydrazine-N atoms of two ligands form the equatorial plane with an average Co–N bond distance of 2.313 Å. The complex cation has a slightly elongated, nanometer-scaled ball shape with the longest diameter of 1.82 nm.     

Strongly decussated π-stacking in a Ag(I)–Co(III) complex containing a Ag2Co2 44 square tile motif

A mixed Co–Ag complex with 2,6-dicarboxypyridine (H₂PDC), AgCo(PDC)₂, was synthesized under hydrothermal conditions. The complex adopts a 2D layer structure formed by intramolecular π-stacking. Each Co(III) ion is chelated by two 2,6-dicarboxypyridine anions to give the [Co(PDC)₂]^? anion that is further extended by Ag⁺ to form 4⁴ square grids.     

Synthesis and crystal structure of the layered cobalt phosphate with racemic 1,2-diaminopropane template

A novel layered cobalt phosphate with a racemic 1,2-diaminopropane templating agent, [CH₂(NH₃)CH(NH₃)-CH₃][CoPO₄]₂, has been synthesized and structurally characterized by single crystal X-ray diffraction. The compound crystallizes in the monoclinic system, space group P2₁/c with a = 10.457(2), b = 7.849(1), c = 6.692(1)?Å, β = 103.30(1)°, V = 534.5(2)?ų, Z = 2. The combination of cobalt phosphate anion layers and doubly protonated cationic 1,2-diaminopropane templates is mainly through ionic bonding. The crystal structure is stabilized by a network of hydrogen bonds between layers and templating agents.