Fifteen subspecies of the wood tiger moth, Arctia plantaginis (Lepidoptera: Erebidae: Arctiinae), have been recorded in the Northern Hemisphere. An analysis of crude pheromone extracts by GC equipped with an electroan...Fifteen subspecies of the wood tiger moth, Arctia plantaginis (Lepidoptera: Erebidae: Arctiinae), have been recorded in the Northern Hemisphere. An analysis of crude pheromone extracts by GC equipped with an electroantennographic (EAG) detector showed four EAG-active components (Comps. I–IV) that were commonly involved in the pheromone glands of two subspecies inhabiting Japan and Finland. Comp. I is a major component (>75%) and the others are minor components (3% - 15%). Their mass spectra, measured by GC/MS, revealed the chemical structures of C21 unsaturated hydrocarbons as follows: 3,6,9-triene for Comp. I, 4,6,9-triene for Comp. II, 1,3,6,9-tetraene for Comp. III, and 2,4,6,9-tetraene for Comp. IV. Comps. I and III are known Type II pheromone compounds, and their retention times coincide with those of the authentic standards with all Z configurations. As a next step, the extract was analyzed by GC/FT-IR to determine the configuration of Comps. II and IV. Their IR spectra showed two characteristic C-H bending absorptions around 990 and 945 cm-1 due to the conjugated dienyl moieties;thus, Z and E configurations were assigned to the double bonds at the 2- and 4-positions, respectively. Their Z double bonds at the 6- and 9-positions are indicated by no absorptions around 970 cm-1, due to the isolated double bonds with E configurations. Finally, the structures of Comps. II and IV were confirmed by synthesis using a double Wittig reaction. The synthetic (4E,6Z,9Z)-4,6,9-triene and (2Z,4E,6Z,9Z)-2,4,6,9-tetraene showed strong EAG activity, and their chemical data coincided well with those of the natural Comps. II and IV, indicating the correctness of the structure determination by GC/FT-IR analysis and its usefulness for Type II pheromone compounds.展开更多
FT-IR spectroscopy online was used to investigate DECP(Diethyl chlorophosphite)degraded by photocatalytic oxidation on nano-TiO2(P25).GC-MS spectrograph was used to analyze the products.It is possible to predict the m...FT-IR spectroscopy online was used to investigate DECP(Diethyl chlorophosphite)degraded by photocatalytic oxidation on nano-TiO2(P25).GC-MS spectrograph was used to analyze the products.It is possible to predict the mechanism of gas-solid phase photocatalytic degradation of DECP.The reaction may be take place by follow pathway:electron-hole couple was produced in illuminated TiO2 by UV irradiated,and the couple evoke reactions with DECP,H2O,-OH to produce various radicals.DECP can be degraded to inorganic compounds by the chain-reaction of radicals.The products include CO2,H2O,CO,HCl,et al.The chain-reaction will be terminated when radicals vanish,and the intermediates were produced,such as methane,alcohol,ethanal,DEHP(Diethyl hydroxyphosphonate),DEP(Diethyl phosphate),TEP(Triethyl phosphate),et al.展开更多
文摘Fifteen subspecies of the wood tiger moth, Arctia plantaginis (Lepidoptera: Erebidae: Arctiinae), have been recorded in the Northern Hemisphere. An analysis of crude pheromone extracts by GC equipped with an electroantennographic (EAG) detector showed four EAG-active components (Comps. I–IV) that were commonly involved in the pheromone glands of two subspecies inhabiting Japan and Finland. Comp. I is a major component (>75%) and the others are minor components (3% - 15%). Their mass spectra, measured by GC/MS, revealed the chemical structures of C21 unsaturated hydrocarbons as follows: 3,6,9-triene for Comp. I, 4,6,9-triene for Comp. II, 1,3,6,9-tetraene for Comp. III, and 2,4,6,9-tetraene for Comp. IV. Comps. I and III are known Type II pheromone compounds, and their retention times coincide with those of the authentic standards with all Z configurations. As a next step, the extract was analyzed by GC/FT-IR to determine the configuration of Comps. II and IV. Their IR spectra showed two characteristic C-H bending absorptions around 990 and 945 cm-1 due to the conjugated dienyl moieties;thus, Z and E configurations were assigned to the double bonds at the 2- and 4-positions, respectively. Their Z double bonds at the 6- and 9-positions are indicated by no absorptions around 970 cm-1, due to the isolated double bonds with E configurations. Finally, the structures of Comps. II and IV were confirmed by synthesis using a double Wittig reaction. The synthetic (4E,6Z,9Z)-4,6,9-triene and (2Z,4E,6Z,9Z)-2,4,6,9-tetraene showed strong EAG activity, and their chemical data coincided well with those of the natural Comps. II and IV, indicating the correctness of the structure determination by GC/FT-IR analysis and its usefulness for Type II pheromone compounds.
文摘FT-IR spectroscopy online was used to investigate DECP(Diethyl chlorophosphite)degraded by photocatalytic oxidation on nano-TiO2(P25).GC-MS spectrograph was used to analyze the products.It is possible to predict the mechanism of gas-solid phase photocatalytic degradation of DECP.The reaction may be take place by follow pathway:electron-hole couple was produced in illuminated TiO2 by UV irradiated,and the couple evoke reactions with DECP,H2O,-OH to produce various radicals.DECP can be degraded to inorganic compounds by the chain-reaction of radicals.The products include CO2,H2O,CO,HCl,et al.The chain-reaction will be terminated when radicals vanish,and the intermediates were produced,such as methane,alcohol,ethanal,DEHP(Diethyl hydroxyphosphonate),DEP(Diethyl phosphate),TEP(Triethyl phosphate),et al.
