http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Bonneaub, R. (검색결과 1 건)
- 무료
- 기관 내 무료
- 유료
-
2,5-Dimethyl-2,4-hexadiene induced photodechlorination of 9,10-dichloroanthracene
Saltiel, J.,Smothers, W.K.,Schanze, K.S.,Charman, S.A.,Bonneaub, R. Korean Society of Photoscience 2009 Photochemical & photobiological sciences Vol.8 No.6
Photochemical formation of 9-chloroanthracene (MCA) from 9,10-dichloroanthracene (DCA) is observed in the presence of 2,5-dimethyl-2,4-hexadiene (DMH) in acetonitrile (AN). The mechanism of the reaction was investigated using kinetics, deuterium labeling, and quenching techniques. Contrary to conclusions in a recent publication, our work supports the salient features of the mechanism we had proposed earlier. DCA is photostable in degassed AN in the absence of DMH. When DMH is added, irradiation of DCA at 365 or 404 nm converts it quantitatively to MCA. The photoreaction is strongly inhibited when low concentrations of molecular oxygen or 1,2,4,5-tetracyanobenzene are also present. Results from fluorescence quenching studies along with kinetics parameters from the dependence of DCA loss and MCA formation quantum yields on [DMH] implicate participation of the DCA/DMH singlet exciplex, the DCA/$(DMH)_2$ triplex and the DCA radical anion ($DCA^{{\cdot}-}$) as intermediates in the photodechlorination. Results from experiments using deuterated DMH, deuterated AN, and AN containing $D_2O$ or $H_2O$ show that the 10-H of MCA is introduced by protonation of $DCA^{{\cdot}-}$. Contrary to a recent report, there is no radical pathway to MCA via dissociation of $DCA^{{\cdot}-}$ to chloride and $MCA^{\cdot}$ radical. Changes in the absorption spectrum of DCA in AN with increasing [DMH] suggest that the static quenching of DCA fluorescence at high [DMH] is due primarily to nearest neighbour quenching instead of DCA/DMH ground state complex formation.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
