72-54-8Relevant articles and documents
Design of a bimetallic Au/Ag system for dechlorination of organochlorides: Experimental and theoretical evidence for the role of the cluster effect
Romashov, Leonid V.,Khemchyan, Levon L.,Gordeev, Evgeniy G.,Koshevoy, Igor O.,Tunik, Sergey P.,Ananikov, Valentine P.
, p. 6003 - 6012 (2014)
The experimental study of dechlorination activity of a Au/Ag bimetallic system has shown formation of a variety of chlorinated bimetallic Au/Ag clusters with well-defined Au:Ag ratios from 1:1 to 4:1. It is the formation of the Au/Ag cluster species that mediated C-Cl bond breakage, since neither Au nor Ag species alone exhibited a comparable activity. The nature of the products and the mechanism of dechlorination were investigated by ESI-MS, GC-MS, NMR, and quantum chemical calculations at the M06/6-311G(d)&SDD level of theory. It was revealed that formation of bimetallic clusters facilitated dechlorination activity due to the thermodynamic factor: C-Cl bond breakage by metal clusters was thermodynamically favored and resulted in the formation of chlorinated bimetallic species. An appropriate Au:Ag ratio for an efficient hydrodechlorination process was determined in a joint experimental and theoretical study carried out in the present work. This mechanistic finding was followed by synthesis of molecular bimetallic clusters, which were successfully involved in the hydrodechlorination of CCl4 as a low molecular weight environment pollutant and in the dechlorination of dichlorodiphenyltrichloroethane (DDT) as an eco-toxic insecticide. High activity of the designed bimetallic system made it possible to carry out a dechlorination process under mild conditions at room temperature.
Photosensitizing catalysis of the B12 complex without an additional photosensitizer
Shimakoshi, Hisashi,Li, Li,Nishi, Masashi,Hisaeda, Yoshio
, p. 10921 - 10923 (2011)
A cobalamin derivative, heptamethyl cobyrinate perchlorate, was activated by UV light irradiation to form a Co(i) species in the presence of triethanolamine and used for a dechlorination reaction, and this photochemical reaction was accelerated in an ionic liquid.
A polymerized ionic liquid-supported B12 catalyst with a ruthenium trisbipyridine photosensitizer for photocatalytic dechlorination in ionic liquids
Zhang, Wei,Shimakoshi, Hisashi,Houfuku, Noriyuki,Song, Xi-Ming,Hisaeda, Yoshio
, p. 13972 - 13978 (2014)
By immobilizing a B12 complex and a Ru(ii) trisbipyridine photosensitizer in a polymerized ionic liquid (PIL), a visible light-driven photocatalyst was developed. The synthesized copolymer was characterized by GPC and DLS, and using UV-vis absorption spectra and luminescence spectra. The Ru(ii) trisbipyridine photosensitizer in the copolymer showed an enhanced emission compared to that of the monomer in the ionic liquid, 1-butyl-4-methylimidazolium bis(trifluoromethanesulfonyl)amide ([C 4mim][NTf2]). Formation of the Co(i) species of the B 12 complex in the copolymer was confirmed by the UV-vis spectral change in [C4mim][NTf2] containing a sacrificial reductant (triethanolamine) under irradiation with visible light. The copolymer showed a high photocatalytic activity in various ionic liquids for 1,1-bis(4- chlorophenyl)-2,2,2-trichloroethane (DDT) dechlorination with ~99% conversion after visible light irradiation for 2 h. Furthermore, both the B 12 catalyst and photosensitizer in the polymer were easily recycled for use with the ionic liquid solvent without any loss of catalytic activity.
Synthesis of a B12-BODIPY dyad for B12-inspired photochemical transformations of a trichloromethylated organic compound
Anai, Yuki,Shichijo, Keita,Fujitsuka, Mamoru,Hisaeda, Yoshio,Shimakoshi, Hisashi
supporting information, p. 11945 - 11948 (2020/10/15)
A B12complex-BODIPY dyad was synthesized by peripheral modification of cobalamin derivatives. The photophysical properties of the dyad were investigated by UV-vis, PL, and transient absorption spectroscopy. A visible light-driven dechlorination reaction of a trichlorinated organic compound, DDT, was reported. The dyad showed efficient catalysis for dechlorination under N2with turnover numbers of over 220 for the reaction. One-pot syntheses of an ester and amide from DDT and benzotrichloride were also achieved using the dyad under air.
Significant enhancement of visible light photocatalytic activity of the hybrid B12-PIL/rGO in the presence of Ru(bpy)32+ for DDT dehalogenation
Sun, Ying,Zhang, Wei,Tong, Jian,Zhang, Yu,Wu, Shuyao,Liu, Daliang,Shimakoshi, Hisashi,Hisaeda, Yoshio,Song, Xi-Ming
, p. 19197 - 19204 (2017/04/10)
A new B12-PIL/rGO hybrid was prepared successfully through immobilizing a B12 derivative on the surface of poly(ionic liquid) (PIL)-modified reduced graphene oxide (rGO) by electrostatic attraction and π-π stacking attraction among the different components. The hybrid catalyst showed an enhanced photocatalytic activity in the presence of Ru(bpy)32+ for 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) dechlorination with ~100% conversion. Especially, the yield of didechlorinated products could reach 78% after 1 h of visible light irradiation, which should be attributed to a synergistic effect of B12, rGO and PIL in B12-PIL/rGO, including their respective catalytic performance, the excellent electron transport of rGO and the concentration of DDT and 1,1-bis(4-chlorophenyl)-2,2-dichloroethane (DDD) on the surface of B12-PIL/rGO. Furthermore, the hybrid catalyst was easily recycled for use without obvious loss of catalytic activity.