Qinghua Meng

Synthesis and properties of some novel soluble metallophthalocyanines containing the 3-trifluromethylphenyoxy moiety

Abstract Some new tetrakis(3-trifluoromethylphenoxy)phthalocyanine complexes with cobalt, nickel or zinc were synthesized and their structures were confirmed by IR, UV–vis, 1H NMR and elemental analysis. These compounds are soluble in weakly and medium polar solvents, but their solubility in strong polar solvents such as DMF and DMSO is fairly low. It was found that the introduction of trifluoromethylphenoxy subtituents greatly affected their spectroscopic properties. The redox peaks of cyclic voltammograms possess good symmetric characteristics, indicating that they are good electron donors, and their electrochemical process is quasireversible with the introduced fluorine group.

CeCl3·7H2O: An Effective Additive in Ru-Catalyzed Enantioselective Hydrogenation of Aromatic α-Ketoesters

In the presence of catalytic amounts of CeCl 3.7H 2O, [RuCl(benzene)(S)-SunPhos]Cl is a highly effective catalyst for the asymmetric hydrogenation of aromatic alpha-ketoesters. A variety of ethyl alpha-hydroxy-alpha-arylacetates have been prepared in up to 98.3% ee with a TON up to 10,000. Challenging aromatic alpha-ketoesters with ortho substituents are also hydrogenated with high enantioselectivities. The addition of CeCl 3.7H 2O not only improves the enantioselectivity but also enhances the stability of the catalyst. The ratio of CeCl 3.7H 2O to [RuCl(benzene)(S)-SunPhos]Cl plays an important role in the hydrogenation reaction with a large substrate/catalyst ratio.

Highly enantioselective sequential hydrogenation of ethyl 2-oxo-4-arylbut-3-enoate to ethyl 2-hydroxy-4-arylbutyrate.

The hydrogenation of (E)-ethyl 2-oxo-4-arylbut-3-enoate with [NH2Me2](+)[{RuCl [(S)-SunPhos]}2(mu-Cl3)] gave ethyl 2-hydroxy-4-arylbutyrate with 94-96% ee. Further investigation has proved that the hydrogenation proceeded via a sequential hydrogenation of CO and CC bonds, which is sensitive to the reaction temperature. Hydrolysis of ethyl 2-hydroxy-4-phenylbutyrate (ee 93%) provided the 2-hydroxy-4-phenylbutyric acid with 81% yield at 99% ee after a single recrystallization from 1,2-dichloroethylene.

A study of third-order nonlinear optical properties for anthraquinone derivatives

Abstract The ground-state geometry, second hyperpolarizabilities of the anthraquinone derivatives have been studied using finite field (FF) The molecular configurations and calculated γ zzzz values are considerably affected by substituents. The third-order nonlinear optical property of 1,4-diamino-2,3-diphenoxy-anthraquinone has been measured using picosecond degenerate four-wave mixing. The third-order nonlinear optical susceptibility χ (3) of the dye is as high as 1.16×10 −12 esu. The second hyperpolarizability (γ) value is 5.71×10 −31 esu.

Melting-reactive dyes for mass coloration of synthetic fibres—part I: perylene-3,4,9,10-tetracarboxylic acid dianhydride in poly(ethyleneterephthalate)

Abstract Mass coloration of poly(ethyleneterephthalate) (PET) by using a melt-reacting dye is described, and affords an economical favorable and environmentally friendly method of coloration. Perylene-3,4,9,10-tetracarboxylic acid dianhydride (PTAD) was used as a melting-reactive dye in poly(ethyleneterephthalate) and showed high thermal stability. A chain-extending reaction was confirmed by UV–vis and IR spectroscopic analysis. The effect of the proportion of the added PTAD on the intrinsic viscosity of the polymer was studied, and increasing amounts resulted in increased intrinsic viscosity. The higher viscosity is beneficial to the spinning process. The light fastness of the colored fibres was as high as 7.

The study of a curcumin-resembling molecular probe for the pH-responsive fluorometric assay and application in cell imaging

A molecular probe of DibOH (2,6-bis(4-hydroxybenzylidene)cyclohexanone) designed as the ameliorant to the curcumin was prepared in which one enol unit was removed to avoid the intramolecular hydrogen bond and thus more rigidity and better coplanarity were achieved. Deprotonation of the phenolic hydroxyl group led to the negative charge and the intramolecular charge transfer (ICT) functioned accordingly. The DibOH probe in basic conditions exhibited the absorption peak at 468 nm, which indicated a red shift of 183 nm relative to that in acid conditions and was visible as a brown color to naked eyes. The ratio of fluorescence intensity at 612 nm to that at 520 nm (I612/I520) was calculated and a clear correlation with the pH value was obtained. The density functional theory (DFT) was performed on theoretical investigation of the acidic and basic forms of DibOH. The DibOH probe was evaluated in fluorescent imaging of human breast cancer cells (MCF-7) wherein the heterogeneous distribution of the intracellular pH microenvironment was observed.

The influence of crystal structure on the dyeing property of 1,4-diamino-2,3-diphenoxyanthraquinone

Abstract X-ray crystal structure of 1,4-diamino-2,3-diphenoxyanthraquinone was determined. The compound C 26 H 18 N 2 O 4 , was monoclinic in P2 1 /a(#14) with a =7.114(2) A, b =19.603(7) A, c =14.611(5) A, β =90.40(3)°, V =2031(1) A 3 , D calc =1.381 g/cm 3 and Z =4. In the molecular structure, the anthraquinone ring retained planarity and both benzene rings were repelled outside the anthraquinone plane. Molecules in the unit cell formed a number of intermolecular hydrogen bonds that led to dye aggregation. Melting-reactive mass coloration of PMMA showed that the dye was a suitable melting-reactive dye.

Melting-reactive dyes for mass coloration of synthetic fibres (II)—1,4-dihydroxyanthraquinone diglycidyl ether in nylon

Mass coloration of nylon using a melting-reactive dye is described. 1,4-Dihydroxyanthraquinone diglycidyl ether was synthesized as a novel melting-reactive dye in which the epoxy groups in the dye would react with amino groups of nylon by a nucleophilic addition mechanism. The dye was confirmed by UV–vis, IR and 1 H NMR spectroscopic analyses. The effect of the proportion of the added dye on the intrinsic viscosity of the polymer was studied. Thermal analysis showed high thermal stability and blending compatibilization. The light fastness of the coloured fibre was measured. # 2001 Elsevier Science Ltd. All rights reserved.