31P NMR has become a widely applied spectroscopic probe of the structure of phosphorus-containing compounds. Meanwhile, the application of 31P NMR has been rapidly expanded to biochemistry and medicinal chemistry of p...31P NMR has become a widely applied spectroscopic probe of the structure of phosphorus-containing compounds. Meanwhile, the application of 31P NMR has been rapidly expanded to biochemistry and medicinal chemistry of phosphorus-containing compounds because the growing importance of the phosphorus compounds is now widely realized. We report here the results of 31P NMR study on some phosphorus-containing compounds, namely, O-alkyl O-4-nitrophenyl methyl phosphonates with different alkyl chain-length (MePO-n), 4-nitrophenyl alkylphenylphosphinates with different alkyl chain-length (PhP-n), diethyl phosphono- acetonitrile anion and diethyl phosphite anion . Our results indicate that 31P NMR can not only be applied to not only the study of the hydrolytic reactions of MePO-8 and PhP-8 but also be applied to the study of the presence of the anions of diethylphosphonoacetonitrile and diethyl phosphite in nucleophilic reactions.展开更多
The line positions of 19F NMR absorption of fluoranil (TFQ) or pentafluorophenylcarboxylate (PFE-16) in the presence of N-alkylphenothiazine donors have been measured. By comparing the 19F chemical shift in C6D6 of TF...The line positions of 19F NMR absorption of fluoranil (TFQ) or pentafluorophenylcarboxylate (PFE-16) in the presence of N-alkylphenothiazine donors have been measured. By comparing the 19F chemical shift in C6D6 of TFQ or PFE-16 in the absence of the donor with thosein the presence of the donor. the difference of these chemical shifts was found to be large. In thepresence of the donor. 19F upheld shifts of TFQ or PFE-16 have been observed. The experimentalresults showed that there is a charge-transfer process between TFQ or PFE-16 and the donor .When TFQ or PFE-16 accepts the charge from the donor. its 19F resonance moves upfield.展开更多
Gamma-cyclodextrin (γ-CD) was used to induce the formation of N,N-diethylaniline (DEA) exciplex in 15:85{φ=0.15)v/v EtOH-H_2O binary mixture.Measurements of the fluorescence spectra of anthracene in the presence or ...Gamma-cyclodextrin (γ-CD) was used to induce the formation of N,N-diethylaniline (DEA) exciplex in 15:85{φ=0.15)v/v EtOH-H_2O binary mixture.Measurements of the fluorescence spectra of anthracene in the presence or absence of DEA and γ-CD show that γ-CD can form 1:1:1 host/guest-Ⅰ/guest-Ⅱ inclusion complex with anthracene and DEA.展开更多
Formation and decay processes of pyrene excimer in acetonitrile have been measured by laser flash spectroscopy at 475nm,and the dependence of λ_1+λ_2 on the pyrene concentration has also been measured at 290°K....Formation and decay processes of pyrene excimer in acetonitrile have been measured by laser flash spectroscopy at 475nm,and the dependence of λ_1+λ_2 on the pyrene concentration has also been measured at 290°K.On the basis of these measurements,six rate parameters which describe the behaviour of pyrene excimer system in acetonitrile solution have been evaluated.At 355 nm laser light irradiation,the ΔG of the pyrene excimer formation in acetonitrile is evaluated to be -30.18kJ/mol. This value is quite different from the corresponding ΔG in cyclohexane (-16.72kJ/mol).展开更多
文摘31P NMR has become a widely applied spectroscopic probe of the structure of phosphorus-containing compounds. Meanwhile, the application of 31P NMR has been rapidly expanded to biochemistry and medicinal chemistry of phosphorus-containing compounds because the growing importance of the phosphorus compounds is now widely realized. We report here the results of 31P NMR study on some phosphorus-containing compounds, namely, O-alkyl O-4-nitrophenyl methyl phosphonates with different alkyl chain-length (MePO-n), 4-nitrophenyl alkylphenylphosphinates with different alkyl chain-length (PhP-n), diethyl phosphono- acetonitrile anion and diethyl phosphite anion . Our results indicate that 31P NMR can not only be applied to not only the study of the hydrolytic reactions of MePO-8 and PhP-8 but also be applied to the study of the presence of the anions of diethylphosphonoacetonitrile and diethyl phosphite in nucleophilic reactions.
文摘The line positions of 19F NMR absorption of fluoranil (TFQ) or pentafluorophenylcarboxylate (PFE-16) in the presence of N-alkylphenothiazine donors have been measured. By comparing the 19F chemical shift in C6D6 of TFQ or PFE-16 in the absence of the donor with thosein the presence of the donor. the difference of these chemical shifts was found to be large. In thepresence of the donor. 19F upheld shifts of TFQ or PFE-16 have been observed. The experimentalresults showed that there is a charge-transfer process between TFQ or PFE-16 and the donor .When TFQ or PFE-16 accepts the charge from the donor. its 19F resonance moves upfield.
文摘Gamma-cyclodextrin (γ-CD) was used to induce the formation of N,N-diethylaniline (DEA) exciplex in 15:85{φ=0.15)v/v EtOH-H_2O binary mixture.Measurements of the fluorescence spectra of anthracene in the presence or absence of DEA and γ-CD show that γ-CD can form 1:1:1 host/guest-Ⅰ/guest-Ⅱ inclusion complex with anthracene and DEA.
文摘Formation and decay processes of pyrene excimer in acetonitrile have been measured by laser flash spectroscopy at 475nm,and the dependence of λ_1+λ_2 on the pyrene concentration has also been measured at 290°K.On the basis of these measurements,six rate parameters which describe the behaviour of pyrene excimer system in acetonitrile solution have been evaluated.At 355 nm laser light irradiation,the ΔG of the pyrene excimer formation in acetonitrile is evaluated to be -30.18kJ/mol. This value is quite different from the corresponding ΔG in cyclohexane (-16.72kJ/mol).
