Coal chemical wastewater(CCW)with the features of high toxicity and poor biodegradability is a big issue in environmental remediation,posing a great threat to aquatic ecosystems and to human beings.Such complex molecu...Coal chemical wastewater(CCW)with the features of high toxicity and poor biodegradability is a big issue in environmental remediation,posing a great threat to aquatic ecosystems and to human beings.Such complex molecular mixtures are notoriously difficult to characterize without initial physical separation.Herein,we present the 3D diffusion ordered spectroscopy(DOSY)analysis for CCW using DOSY-COSY and DOSY-HSQC methods,the advantages of this strategy have been demonstrated in the analysis of mixtures of aliphatic oxygenates and aromatic compounds,before being implemented on a genuine CCW sample in this study.The results showed that 3D DOSY is a robust and reliable tool for providing superior resolution and virtual separation of complex pollutants,and can be used as a general approach for structural elucidation.展开更多
DOSY(diffusion ordered spectroscopy)NMR is a technique that separates NMR signals of different species according to their diffusion coefficients.It is a powerful technique to provide solid characterization evidence fo...DOSY(diffusion ordered spectroscopy)NMR is a technique that separates NMR signals of different species according to their diffusion coefficients.It is a powerful technique to provide solid characterization evidence for various applications in the chemical industry.Encapsulation and functional polymer grafting are two important capabilities in the chemical industry for new product development with challenging characterization requirements.Model systems of encapsulation and grafted polymer were studied and the characterization methods were set up by DOSY NMR.展开更多
Intradiffusion coefficients of acetylacetone(AcAc) and DMF/DMSO/benzene in binary systems over the entire concentration range at 303.15 K were determined by 1H diffusion-order spectroscopy(DOSY) nuclear magnetic reson...Intradiffusion coefficients of acetylacetone(AcAc) and DMF/DMSO/benzene in binary systems over the entire concentration range at 303.15 K were determined by 1H diffusion-order spectroscopy(DOSY) nuclear magnetic resonance(NMR) method based pulse field gradient(PFG).The densities and viscosities of the above three binary systems at 303.15 K were also studied and employed to calculate the excess molar volumes(V^E) and deviations in viscosity(△η).Besides,experiments were carried out at 333.15 K for the system of AcAc+DMF.The solvent and temperature effect upon the difference in D between enol and keto tautomers,the tautomeric equilibrium and excess properties(V^E and △η) were discussed as well.Isotherms of V^E as a function of mole fraction of AcAc(χ_1) show positive deviations in benzene but negative deviations in DMF and DMSO,whereas isotherms of △ηas a function of χ_1 record positive deviations in DMF but negative in benzene and DMSO.V^E values show more negative and △η values are less positive in the system of AcAc+DMF at 333.15 K compared to 303.15 K.The V^E and △η were fitted to a Redlich-Kister type equation and the measured results were interpreted concerning molecular interactions in the solutions.展开更多
The reaction system of diperoxooxalatovanadate {K3[VO(O2)2-(C2O4)]·H2O, bpV(Oxa)} and imidazole was studied in an aqueous solution by 1D multinuclear (1H, 13C and 51V) NMR, 2D NMR diffusion ordered spectroscopy (...The reaction system of diperoxooxalatovanadate {K3[VO(O2)2-(C2O4)]·H2O, bpV(Oxa)} and imidazole was studied in an aqueous solution by 1D multinuclear (1H, 13C and 51V) NMR, 2D NMR diffusion ordered spectroscopy (DOSY), and variable temperature NMR techniques. It was shown that DOSY was a useful tool for the study of a mixture. All of the 1H and 13C NMR signals of the peroxovanadate (V) complexes were assigned. The NMR experimental results indicated that a new complex was formed through the coordination interactions between bpV(Oxa) and imidazole. The newly-formed complex is stable under the experimental condition. Electrospray ioniza-tion mass spectrometry (ESI-MS) provides positive evidence to support the conclusion.展开更多
基金The authors thank for National Natural Science Foundation of China(U1710106)for financial support.
文摘Coal chemical wastewater(CCW)with the features of high toxicity and poor biodegradability is a big issue in environmental remediation,posing a great threat to aquatic ecosystems and to human beings.Such complex molecular mixtures are notoriously difficult to characterize without initial physical separation.Herein,we present the 3D diffusion ordered spectroscopy(DOSY)analysis for CCW using DOSY-COSY and DOSY-HSQC methods,the advantages of this strategy have been demonstrated in the analysis of mixtures of aliphatic oxygenates and aromatic compounds,before being implemented on a genuine CCW sample in this study.The results showed that 3D DOSY is a robust and reliable tool for providing superior resolution and virtual separation of complex pollutants,and can be used as a general approach for structural elucidation.
文摘DOSY(diffusion ordered spectroscopy)NMR is a technique that separates NMR signals of different species according to their diffusion coefficients.It is a powerful technique to provide solid characterization evidence for various applications in the chemical industry.Encapsulation and functional polymer grafting are two important capabilities in the chemical industry for new product development with challenging characterization requirements.Model systems of encapsulation and grafted polymer were studied and the characterization methods were set up by DOSY NMR.
基金Supported by the National Natural Science Foundation of China(20173074)the Natural Science Foundation of Guangdong Provinces(031583)
文摘Intradiffusion coefficients of acetylacetone(AcAc) and DMF/DMSO/benzene in binary systems over the entire concentration range at 303.15 K were determined by 1H diffusion-order spectroscopy(DOSY) nuclear magnetic resonance(NMR) method based pulse field gradient(PFG).The densities and viscosities of the above three binary systems at 303.15 K were also studied and employed to calculate the excess molar volumes(V^E) and deviations in viscosity(△η).Besides,experiments were carried out at 333.15 K for the system of AcAc+DMF.The solvent and temperature effect upon the difference in D between enol and keto tautomers,the tautomeric equilibrium and excess properties(V^E and △η) were discussed as well.Isotherms of V^E as a function of mole fraction of AcAc(χ_1) show positive deviations in benzene but negative deviations in DMF and DMSO,whereas isotherms of △ηas a function of χ_1 record positive deviations in DMF but negative in benzene and DMSO.V^E values show more negative and △η values are less positive in the system of AcAc+DMF at 333.15 K compared to 303.15 K.The V^E and △η were fitted to a Redlich-Kister type equation and the measured results were interpreted concerning molecular interactions in the solutions.
基金Project supported by the National Natural Science Foundation of China(Nos.Grants 10234070,10104011)and the Naturral Science Foundation of Fujian Province(No.Grant E0110003).
文摘The reaction system of diperoxooxalatovanadate {K3[VO(O2)2-(C2O4)]·H2O, bpV(Oxa)} and imidazole was studied in an aqueous solution by 1D multinuclear (1H, 13C and 51V) NMR, 2D NMR diffusion ordered spectroscopy (DOSY), and variable temperature NMR techniques. It was shown that DOSY was a useful tool for the study of a mixture. All of the 1H and 13C NMR signals of the peroxovanadate (V) complexes were assigned. The NMR experimental results indicated that a new complex was formed through the coordination interactions between bpV(Oxa) and imidazole. The newly-formed complex is stable under the experimental condition. Electrospray ioniza-tion mass spectrometry (ESI-MS) provides positive evidence to support the conclusion.
