A novel and efficient route for the synthesis of 1,8-dioxooctahydroxanthenes and 14-aryl-14H-dibenzo[a,j]xanthenes is described through one-pot multi-component reaction of dimedone and 2-naphthol with various aryl ald...A novel and efficient route for the synthesis of 1,8-dioxooctahydroxanthenes and 14-aryl-14H-dibenzo[a,j]xanthenes is described through one-pot multi-component reaction of dimedone and 2-naphthol with various aryl aldehydes using ZnO nanoparticles under solvent-free conditions. This method provides a novel and improved pathway for the synthesis of xanthenes in the terms of excellent yields, short reaction times, reusability and low catalyst loading.展开更多
A simple and efficient procedure for the preparation of aryl- 14-H-dibenzo [aj]xanthenes by a one-pot condensation reaction of 2-naphthol and aryl aldehydes, in the presence of silica supported sodium hydrogen sulfate...A simple and efficient procedure for the preparation of aryl- 14-H-dibenzo [aj]xanthenes by a one-pot condensation reaction of 2-naphthol and aryl aldehydes, in the presence of silica supported sodium hydrogen sulfate （NaHSO4/SiO2） as a catalyst and in the absence of solvent has been developed. The present method offers several advantages such as excellent yields, short reaction time （10-30min）, mild condition, simple work-up, and the use of a cheap and environmentally friendly catalyst with remarkable reusability.展开更多
In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Sim...In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.展开更多
1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in re...1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in relatively short reaction times in good to high yields.展开更多
A new fluorinated poly(ether amide) bearing xanthene group was prepared from 9,9-bis[4-(2-trifluoromethyl-4-aminophenox- y)phenyl]xanthene (BTFAPX) with 9,9-bis[4-(4-carboxyphenoxy)phenyl]xanthene (BCAPX) in the prese...A new fluorinated poly(ether amide) bearing xanthene group was prepared from 9,9-bis[4-(2-trifluoromethyl-4-aminophenox- y)phenyl]xanthene (BTFAPX) with 9,9-bis[4-(4-carboxyphenoxy)phenyl]xanthene (BCAPX) in the presence of triphenyl phos- phate and pyridine (Py). The polymer had the weight-average molecular weight (Mw) of 69,000 and number-average molecular weight (Mn) of 39,000, showed the glass transition temperature (Tg) of 267 ℃, 5% weight loss temperature (Tds) over 460 ℃ both in N2 and air, and char yield of 62% at 800 ℃ in N2. This polymer was amorphous and readily soluble in amide-type solvents such as N,N-dimethylacetamide (DMAc), and even in m-cressol, Py and tetrahydrofuran (THF) at room temperature, and exhibited tensile strength of 74 MPa, elongation at break of 6%, tensile moduli of 2.2 GPa. The polymer had low dielectric constant of 3.69 (100 Hz), low moisture absorption of 0.56%, and high transparency with an ultraviolet-visible absorption cut-off wavelength at 334 nm.展开更多
A novel biomimetic catalyst of complex Cu(p-OTs) 2/ethanolamine(1∶1) was used to oxidize 1,1′-bi-2-naphthol into xanthene derivatives with a relative high yield in a mixed solvents of dimethyl sulfoxide(DMSO) and C...A novel biomimetic catalyst of complex Cu(p-OTs) 2/ethanolamine(1∶1) was used to oxidize 1,1′-bi-2-naphthol into xanthene derivatives with a relative high yield in a mixed solvents of dimethyl sulfoxide(DMSO) and CH 3OH. The studies on the effect of some solvents on the yield of xanthene derivatives indicates that the yield reduces dramatically with the increase of the content of H 2O in the mixed solvents of H 2O and DMSO. No product can be obtained when the content of H 2O is up to 70%. The cyclic voltammetric study demonstrated that the copper ion in complex Cu(p-OTs) 2/ethanolamine(1∶1) is reduced via a two-step one-electron reduction process from Cu(Ⅱ) to Cu in the mixture of DMSO and H 2O. Water as a poor solvent in respect to the reactants probably hampered the coordination of 1,1′-bi-2-naphthol to copper/amine complex and led to the insufficient catalytic efficiency of complex Cu(p-OTs) 2/ethanolamine(1∶1).展开更多
Spectrophotometric determination of molybdenum, zinc, cobalt(Ⅱ), indium, selenium (Ⅳ), iron (Ⅲ), vanadium (Ⅴ), which is based on the ion-associate complexes formed by the reaction of metal ion-thiocyanate anionic ...Spectrophotometric determination of molybdenum, zinc, cobalt(Ⅱ), indium, selenium (Ⅳ), iron (Ⅲ), vanadium (Ⅴ), which is based on the ion-associate complexes formed by the reaction of metal ion-thiocyanate anionic complexes with some basic dyes in aqueous solution in the presence of a surfactant has been reported.展开更多
A facile and efficient synthesis of 14-fluorophenyl-14H-dibenzo[a,j]xanthenes has been developed by one-pot condensation of fluorinated benzaldehydes with β-naphthol in the presence of p-TSA·H2O under microwave ...A facile and efficient synthesis of 14-fluorophenyl-14H-dibenzo[a,j]xanthenes has been developed by one-pot condensation of fluorinated benzaldehydes with β-naphthol in the presence of p-TSA·H2O under microwave irradiation and solvent-free conditions. These products are conveniently oxidized to 14-fluorophenyl-14-hydroxydibenzo[a,j]xanthenes by PbO2 in acetic acid in good yields.展开更多
A novel polyamide containing xanthene structure and trifluoromethylphenoxy pendent was prepared from 9,9-bis[4-(4- aminophenoxy)phenyl]xanthene,a novel diamine with 2-(4-trifluoromethylphenoxy)terephthaloyl chloride,b...A novel polyamide containing xanthene structure and trifluoromethylphenoxy pendent was prepared from 9,9-bis[4-(4- aminophenoxy)phenyl]xanthene,a novel diamine with 2-(4-trifluoromethylphenoxy)terephthaloyl chloride,by the low temperature polycondensation.This new polyamide with the inherent viscosity of 0.95 dL/g was amorphous and readily soluble in polar solvents such as DMAc,m-cresol,etc.This polyamide showed the glass transition temperature(T_g) of 236℃,decomposition temperature (Td) at 5%weight loss of...展开更多
基金University of Kashan for supporting this work by Grant 159196/ⅦIran National Science Foundation for supporting this work
文摘A novel and efficient route for the synthesis of 1,8-dioxooctahydroxanthenes and 14-aryl-14H-dibenzo[a,j]xanthenes is described through one-pot multi-component reaction of dimedone and 2-naphthol with various aryl aldehydes using ZnO nanoparticles under solvent-free conditions. This method provides a novel and improved pathway for the synthesis of xanthenes in the terms of excellent yields, short reaction times, reusability and low catalyst loading.
基金the K.N.Toosi University of Technology Research Council for financial support.
文摘A simple and efficient procedure for the preparation of aryl- 14-H-dibenzo [aj]xanthenes by a one-pot condensation reaction of 2-naphthol and aryl aldehydes, in the presence of silica supported sodium hydrogen sulfate （NaHSO4/SiO2） as a catalyst and in the absence of solvent has been developed. The present method offers several advantages such as excellent yields, short reaction time （10-30min）, mild condition, simple work-up, and the use of a cheap and environmentally friendly catalyst with remarkable reusability.
基金the University of Guilan Research Council for the partial support
文摘In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.
基金the University of Guilan Research Council for the partial support
文摘1,3-Dibromo-5,5-dimethylhydantoin, has been used as an efficient catalyst for the synthesis of 14-aryl-14H-dibenzo[a,j]- xanthenes in the presence of kaolin. All reactions are performed in the absence of solvent in relatively short reaction times in good to high yields.
基金National Natural Science Foundation of China(No.20664001)the Research Program of Jiangxi Province Department of Education(No.2007-123,GJJ08166 and GJJ09138) for the financial support
文摘A new fluorinated poly(ether amide) bearing xanthene group was prepared from 9,9-bis[4-(2-trifluoromethyl-4-aminophenox- y)phenyl]xanthene (BTFAPX) with 9,9-bis[4-(4-carboxyphenoxy)phenyl]xanthene (BCAPX) in the presence of triphenyl phos- phate and pyridine (Py). The polymer had the weight-average molecular weight (Mw) of 69,000 and number-average molecular weight (Mn) of 39,000, showed the glass transition temperature (Tg) of 267 ℃, 5% weight loss temperature (Tds) over 460 ℃ both in N2 and air, and char yield of 62% at 800 ℃ in N2. This polymer was amorphous and readily soluble in amide-type solvents such as N,N-dimethylacetamide (DMAc), and even in m-cressol, Py and tetrahydrofuran (THF) at room temperature, and exhibited tensile strength of 74 MPa, elongation at break of 6%, tensile moduli of 2.2 GPa. The polymer had low dielectric constant of 3.69 (100 Hz), low moisture absorption of 0.56%, and high transparency with an ultraviolet-visible absorption cut-off wavelength at 334 nm.
文摘A novel biomimetic catalyst of complex Cu(p-OTs) 2/ethanolamine(1∶1) was used to oxidize 1,1′-bi-2-naphthol into xanthene derivatives with a relative high yield in a mixed solvents of dimethyl sulfoxide(DMSO) and CH 3OH. The studies on the effect of some solvents on the yield of xanthene derivatives indicates that the yield reduces dramatically with the increase of the content of H 2O in the mixed solvents of H 2O and DMSO. No product can be obtained when the content of H 2O is up to 70%. The cyclic voltammetric study demonstrated that the copper ion in complex Cu(p-OTs) 2/ethanolamine(1∶1) is reduced via a two-step one-electron reduction process from Cu(Ⅱ) to Cu in the mixture of DMSO and H 2O. Water as a poor solvent in respect to the reactants probably hampered the coordination of 1,1′-bi-2-naphthol to copper/amine complex and led to the insufficient catalytic efficiency of complex Cu(p-OTs) 2/ethanolamine(1∶1).
基金Supported by the National Natural Science Foundation of China
文摘Spectrophotometric determination of molybdenum, zinc, cobalt(Ⅱ), indium, selenium (Ⅳ), iron (Ⅲ), vanadium (Ⅴ), which is based on the ion-associate complexes formed by the reaction of metal ion-thiocyanate anionic complexes with some basic dyes in aqueous solution in the presence of a surfactant has been reported.
基金Project supported by the National Natural Science Foundation of China （Nos. 20972092 and 21032006）.
文摘A facile and efficient synthesis of 14-fluorophenyl-14H-dibenzo[a,j]xanthenes has been developed by one-pot condensation of fluorinated benzaldehydes with β-naphthol in the presence of p-TSA·H2O under microwave irradiation and solvent-free conditions. These products are conveniently oxidized to 14-fluorophenyl-14-hydroxydibenzo[a,j]xanthenes by PbO2 in acetic acid in good yields.
基金the National Natural Science Foundation of China(No.20664001)the Research Program of Jiangxi Province Department of Education(No.2007-123,GJJ08166 and GJJ09138) for the financial support
文摘A novel polyamide containing xanthene structure and trifluoromethylphenoxy pendent was prepared from 9,9-bis[4-(4- aminophenoxy)phenyl]xanthene,a novel diamine with 2-(4-trifluoromethylphenoxy)terephthaloyl chloride,by the low temperature polycondensation.This new polyamide with the inherent viscosity of 0.95 dL/g was amorphous and readily soluble in polar solvents such as DMAc,m-cresol,etc.This polyamide showed the glass transition temperature(T_g) of 236℃,decomposition temperature (Td) at 5%weight loss of...
