US EPA

1754331 

Journal Article 

Dechlorination of DDT catalyzed by visible-light-driven system composed of vitamin B-12 derivative and Rhodamine B 

Tahara, K; Mikuriya, K; Masuko, T; Kikuchi, J; Hisaeda, Y 

2013 

Yes 

Journal of Porphyrins and Phthalocyanines
ISSN: 1088-4246 

WORLD SCI PUBL CO INC 

HACKENSACK 

17 

1-2 

135-141 

English 

10.1142/S1088424612501398 

WOS:000316949700015 

The visible-light-driven dechlorination of 1,1-bis(4 chlorophenyl)-2,2,2-trichloroethane (DDT) was carried out in the presence of a hydrophobic
vitamin B-12, heptamethyl cobyrinate perchlorate and Rhodamine B. DDT was successfully
dechlorinated to form 1,1-bis(4-chlorophenyl)2,2-dichloroethane (DDD) as the mono-dechlorinated
product upon visible light irradiation with a tungsten lamp (lambda > 440 nm). Upon prolonged
visible light irradiation to DDT, DDMU (1-chloro-2,2-bis(4-chlorophenyl)ethylene), DDMS (1-
chloro-2,2-bis(4-chlorophenyl) ethane) and DCS (trans-4,4'-dichlorostilbene) were obtained as
the di- and tri-dechlorinated products. The use of the photostable organic sensitizer enabled
prolonged photocatalysis via a noble-metal-free process. The vitamin B-12 derivative was replaced
by an imine/oxime-type cobalt complex although the cobalt complex system showed a lower catalytic
activity than the B-12 derivative system. The dechlorination mechanism in the B-12-Rhodamin B
system was investigated by various methods such as UV-vis absorption and fluorescence quenching. 

vitamin B-12; Rhodamine B; organic photosensitizer; DDT; dechlorination; visible-light-driven catalysis