617-43-6Relevant articles and documents
Degradation of chlorinated phenols in water in the presence of H 2O2 and water-soluble μ-nitrido diiron phthalocyanine
Colomban, Cédric,Kudrik, Evgeny V.,Afanasiev, Pavel,Sorokin, Alexander B.
, p. 14 - 19 (2014/08/18)
Efficient disposal of pollutants is a key problem in the environmental context. In particular, chlorinated aromatic compounds are recalcitrant to biodegradation and conventional treatment methods. Iron phthalocyanines were previously shown to be efficient catalysts for the oxidative degradation of chlorinated phenols considered as priority pollutants. We have recently discovered μ-nitrido diiron phthalocyanines as powerful oxidation catalysts. Herein, we evaluate these emerging catalysts in the oxidation of chlorinated phenols in comparison with conventional mononuclear complex. Catalytic performance of iron tetrasulfophthalocyanine (FePcS) and corresponding μ-nitrido dimer [(FePcS)2N] have been compared in the oxidation of chlorinated phenols by hydrogen peroxide in water. The oxidative degradation of 2,6-dichlorophenol (DCP) and 2,4,6-trichlorophenol (TCP) has been studied. The (FePcS)2N exhibited better catalytic properties than mononuclear FePcS in terms of conversion and mineralization (transformation of organic chlorine to Cl- and decrease of total organic carbon due to the formation of CO2). Kinetics of the DCP oxidation indicated that different reaction mechanisms are involved in the presence of FePcS and (FePcS)2N. The high catalytic activity of (FePcS)2N in the degradation and mineralization of chlorinated phenols make μ-nitrido diiron phthalocyanines promising catalyst to apply also in environmental remediation.
Metallophthalocyanines linked to organic copolymers as efficient oxidative supported catalysts
Sanchez, Muriel,Chap, Nicolas,Cazaux, Jean-Bernard,Meunier, Bernard
, p. 1775 - 1783 (2007/10/03)
The covalent anchoring of metallo(chlorosulfonyl)phthalocyanines 1 onto the acrylic copolymers 2 and 3 has been achieved. When using H2O2 or KHSO5 as oxidant, these supported catalysts are able to oxidize a poorly biodegradable molecule such as 2,4,6-trichlorophenol or a tannin model such as 3,5-di-tert-butylcatechol. The influence of the spacer and the nature of the reaction medium on the catalytic activities have been studied, as well as the recycling of these supported metallophthalocyanine catalysts.
Regioselectivity of metal hydride reductions of unsymmetrically substituted cyclic anhydrides. Systems where "steric hindrance along the preferred reaction path" rationalization is not applicable
Kayser, Margaret M.,Morand, Peter
, p. 2484 - 2490 (2007/10/02)
Metal hydride reductions of planar cyclic anhydrides such as methylmaleic or 3-substituted phthalic anhydrides occur preferentially at the sterically more hindered carbonyl function.This regioselectivity cannot be rationalized in terms of "the most favourable pathway for non-perpendicular attack by a nucleophile" since both carbonyl groups present are equally accessible to non-perpendicular approach.A study which takes into account the alkaline cation and inductive, mesomeric, and steric effects has been conducted for the reduction of several conjugated and aromatic anhydrides.A qualitative interpretation for the regioselectivities observed in these reductions (as well as in reductions already reported in the literature) is suggested.An early transition state for the catalyzed versus late transition state for the non-catalyzed process is proposed.
