36954-67-3Relevant academic research and scientific papers
Photochemical dechlorination of DDT catalyzed by a hydrophobic vitamin B12 and a photosensitizer under irradiation with visible light.
Shimakoshi, Hisashi,Tokunaga, Mami,Baba, Tatsushi,Hisaeda, Yoshio
, p. 1806 - 1807 (2004)
Dechlorination of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) was catalyzed by a hydrophobic vitamin B(12), heptamethyl cobyrinate perchlorate, with a visible light irradiation system containing a [Ru(ii)(bpy)(3)]Cl(2) photosensitizer, and the hydrophobic vitamin B(12) showed high catalytic efficiency and stability during the reaction.
Hydrophobic vitamin B12· part 19: Electroorganic reaction of DDT mediated by hydrophobic vitamin B12
Shimakoshi, Hisashi,Tokunaga, Mami,Hisaeda, Yoshio
, p. 878 - 882 (2004)
The controlled-potential electrolysis of 1,1-bis(4-chlorophenyl)-2,2,2- trichloroethane (DDT) was carried out at -1.4 V vs. Ag-AgCl in the presence of a hydrophobic vitamin B12, heptamethyl cobyrinate perchlorate. DDT was dechlorinated to form 1,1-bis(4-chlorophenyl)-2,2-dichloroethane (DDD), 1,1-bis(4-chlorophenyl)-2,2-dichloroethylene (DDE), 1-chloro-2,2-bis(4- chlorophenyl)ethylene (DDMU) and 1,1,4,4-tetrakis(4-chlorophenyl)-2,3-dichloro- 2-butene (TTDB) (E/Z), and quantitative recovery of the catalyst after the electrolysis was confirmed by electronic spectroscopy. A photo-sensitive intermediate having a cobalt-carbon bond formed during the electrolysis was characterized by electronic spectroscopy. A mechanism for the formation of various dechlorinated products was investigated by using deuterium solvents and various spectroscopic measurements such as UV-VIS and the EPR spin-trapping technique.
Photocatalytic function of the B12 complex with the cyclometalated iridium(III) complex as a photosensitizer under visible light irradiation
Tian, Hui,Shimakoshi, Hisashi,Park, Gyurim,Kim, Sinheui,You, Youngmin,Hisaeda, Yoshio
, p. 675 - 683 (2018/02/16)
A visible light induced three-component catalytic system with the cobalamin derivative (B12) as a catalyst, the cyclometalated iridium(iii) complex (Irdfppy, Irppy, Irpbt and [Ir{dF(CF3)ppy}2(dtbpy)]PF6) as a photosensitizer and triethanolamine as an electron source under N2 was developed. This catalytic system showed a much higher catalytic efficiency than the previous catalytic system using [Ru(ii)(bpy)3]Cl2 as the photosensitizer for the dechlorination reaction of 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT). Noteworthy is the fact that the remarkable high turnover number (over ten thousand) based on B12, which ranks at the top among the reported studies, was obtained when Irdfppy was used as a photosensitizer. This photocatalytic system was also successfully applied to the B12 enzyme-mimic reaction, i.e., the 1,2-migration of the phenyl group of 2-bromomethyl-2-phenylmalonate. The plausible reaction mechanism was proposed, which involved two quenching pathways, an oxidative quenching pathway and a reductive quenching pathway, to be responsible for the initial electron transfer of the excited-state photosensitizers during the DDT dechlorination reaction. Transient photoluminescence experiments revealed that the oxidative quenching of the photosensitizer dominated over the reductive quenching pathway.
Supramolecular system composed of B12 model complex and organic photosensitizer: Impact of the corrin framework of B12 on the visible-light-driven dechlorination without the use of noble metals
Tahara, Keishiro,Mikuriya, Kumiko,Masuko, Takahiro,Kikuchi, Jun-Ichi,Hisaeda, Yoshio
, p. 141 - 150 (2016/02/09)
The visible-light-driven dechlorination system without the use of a noble metal has been developed. We screened the combination of cobalt catalysts having square-planar monoanionic ligands (hydrophobic B12 model complex 1/imine-oxime type complex 2) and typical red dyes (Rose Bengal 3/Rhodamine B 4/Nile Red 5) for the construction of a dehalogenation system via a noble-metal-free and visible-light-driven process. The combination of the hydrophobic B12 model complex 1 and Rose Bengal 3 exhibited the highest catalytic activity to 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) to form the monodechlorinated compound, 1,1-bis(4-chlorophenyl)-2,2-dichloroethane, as the major product. The prolonged photocatalysis of DDT by the B12-Rose Bengal system afforded the tri-dechlorinated compound, trans-4,4′-dichlorostilbene, as the major product. Furthermore, we investigated the mechanism of the dehalogenation cycle using various methods such as UV-vis spectroscopy and laser flash photolysis. Finally, we clarified the advantage of using the hydrophobic B12 model complex 1 as an electron acceptor as well as a cobalt catalyst in the organic dye-involved photocatalysis.
Eco-friendly molecular transformations catalyzed by a vitamin B 12 derivative with a visible-light-driven system
Tahara, Keishiro,Hisaeda, Yoshio
supporting information; experimental part, p. 558 - 561 (2011/05/08)
A new bio-inspired system composed of a vitamin B12 derivative and Rose Bengal, catalyzed the dehalogenations of various toxic alkyl halides such as 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) via a noble-metal-free and visible-light-driven process. This system also catalyzed radical-involved organic reactions such as the 1,2-migration of acyl group via a tin-free process. The Royal Society of Chemistry.
B12-TiO2 hybrid catalyst for dehalogenation of organic halides
Shimakoshi, Hisashi,Sakumori, Emiko,Kaneko, Kenji,Hisaeda, Yoshio
scheme or table, p. 468 - 469 (2010/03/04)
A cobalamin derivative, cobyrinie acid, was effectively immobilized on TiO2, and the hybrid TiO2 was characterized by UV-vis, XPS, MALDI-TOFMS as well as TEM analysis. The hybrid TiO2 exhibits high reactivity for dehalogenation of various organic halides such as phenethyl bromide, benzyl bromide, and 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) under irradiation with UV light at room temperature. Copyright
