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Crystal-to-crystal transformation from the triclinic to the cubic crystal system by partial desolvation

Qianqian Guo, Irmgard Kalf, Ulli Englert

《化学科学与工程前沿（英文）》 2018年第12卷第3期页码 433-439 doi: 10.1007/s11705-018-1743-6

摘要：

Diffusion reaction of the labile building block Mg(acacCN)₂ (acacCN= 3-cyanoacetylacetonate) with silver salts leads to a series of solvated Mg/Ag bimetallic coordination polymers with composition [Mg(acacCN)₃Ag]·solvent. Despite their common stoichiometry, the topology of these polymers depends on the solvent of crystallization. The two-dimensional coordination compound [Mg(acacCN)₃Ag]·4CHCl₃ in space group P $\overset{&OverBar;}{1}$ is obtained as platelet-shaped crystals from a mixture of methanol and chloroform. When kept in the reaction mixture, these thin plates within one week convert to isometric tetrahedral crystals of the 3D network [Mg(acacCN)₃Ag]·2CHCl₃ in the cubic space group P2₁3. The transformation reaction proceeds via dissolution and recrystallization. The co-crystallized solvent molecules play an important role for stabilizing the target structure: They subtend Cl···Cl contacts and interact via non-classical C–H···O hydrogen bonds with the coordination framework. In the new cubic coordination network, both Mg(II) and Ag(I) adopt octahedral coordination, with unprecedented face-sharing by bridging O atoms of three acetylacetonato moieties. Prolonged standing of [Mg(acacCN)₃Ag]·2CHCl₃ in the reaction medium leads to further degradation, under formation of [Ag(acacCN)].

关键词： ditopic ligand substituted acetylacetone desolvation diffraction

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Synthesis of p -substituted tetraphenylporphyrins and corresponding ferric complexes with mixed-solvents

Zhicheng SUN, Yuanbin SHE, Rugang ZHONG,

《化学科学与工程前沿（英文）》 2009年第3卷第4期页码 457-461 doi: 10.1007/s11705-009-0169-6

摘要： By using mixed-solvents method, five kinds of -substituted tetraphenylporphyrin compounds [T(-R)PPH, R=NO, Cl, CH, OCH, OH] were synthesized by the condensation of -substituted benzaldehyde with pyrrole in mixed solvents (propionic acid, acetic acid and nitrobenzene), and corresponding ferric complexes [T(-R)PPFeCl] were synthesized in dimethylformamide. The above free base porphyrins were obtained in 30%–50% yields, metalation yields were up to 90% and total yields of ferric complexes were 27%–50%. Effects of reactive conditions, solvents and oxidants on yields of free base porphyrins were investigated and the relevant mechanism was discussed. Structures of the above porphyrin complexes were characterized by ultraviolet-visible (UV-Vis), infrared (IR) and far infrared (FIR) spectroscopy.

关键词： -substituted tetraphenylporphyrin condensation -substituted benzaldehyde dimethylformamide metalation

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Synthesis and properties of water-soluble 1,9-dialkyl-substituted BF

Dan Wu, Gonzalo Durán-Sampedro, Donal F. O’Shea

《化学科学与工程前沿（英文）》 2020年第14卷第1期页码 97-104 doi: 10.1007/s11705-019-1828-x

摘要： Bis-alkylsulfonic acid and polyethylene glycol (PEG)-substituted BF azadipyrromethenes have been synthesized by an adaptable and versatile route. Only four synthetic stages were required to produce the penultimate fluorophore compounds, containing either two alcohol or two terminal alkyne substituents. The final synthetic step introduced either sulfonic acid or polyethylene glycol groups to impart aqueous solubility. Sulfonic acid groups were introduced by reaction of the bis-alcohol-substituted fluorophore with sulfur trioxide, and a double Cu(I)-catalyzed cycloaddition reaction between the bis-alkyne fluorophore and methoxypolyethylene glycol azide yielded a neutral bis-pegylated derivative. Both fluorophores exhibited excellent near-infrared (NIR) photophysical properties in methanol and aqueous solutions. Live cell microscopy imaging revealed efficient uptake and intracellular labelling of cells for both fluorophores. Their simple synthesis, with potential for last-step structural modifications, makes the present NIR-active azadipyrromethene derivatives potentially useful as NIR fluorescence imaging probes for live cells.

关键词： NIR-fluorophores live cell imaging NIR-AZA

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Direct synthesis of diphenyl carbonate over heterogeneous catalyst: effects of structure of substituted

WU Guangwen, JIN Fang, WU Yuxin, ZHANG Guangxu, LI Dinghuo, WANG Cunwen, MA Peisheng

《化学科学与工程前沿（英文）》 2007年第1卷第1期页码 59-64 doi: 10.1007/s11705-007-0012-x

摘要： The perovskite-type compound LaMnO was substituted for the part of La in position A and for the part of Mn in position B by citrate method. The phases were detected by X-ray diffraction. Powder morphologies were scanned by scanning electron microscopy. The valence of atoms was determined by X-ray photoelectron spectroscopy. It was found that the perovskite can form crystal defect and increase the proportion of high valence B element by doping. Active component Pd was loaded on various perovskite supports for synthesis of diphenyl carbonate. The results showed that the activities of catalysts in which supports have crystal defect by substitution were higher. It can be concluded that perovskite with defect structure by doping could lead to the formation of oxygen vacancy where the lattice oxygen became exchangeable with the oxygen gas. Also, this improved the redox process of the carrier by transferring electrons and activities of catalysts.

关键词： photoelectron spectroscopy diphenyl carbonate proportion diffraction perovskite