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Zinc(II) phthalocyanines immobilized in mesoporous silica Al-MCM-41 and their a...
Silva, M.; Calvete, M. J. F.; Gonçalves, N. P. F.; Burrows, H. D.; Sarakha, M.; Fernandes, A.; Ribeiro, M. F.; Azenha, M. E; Pereira, M. M.In the present study the authors investigated a set of three new zinc(II) phthalocyanines (zinc(II) tetranitrophthalocyanine (ZnTNPc), zinc(II) tetra(phenyloxy)phthalocyanine (ZnTPhOPc) and the tetraiodide salt of zinc(II)tetra(N,N,N-trimethylaminoethyloxy) phthalocyaninate (ZnTTMAEOPcI)) immobilized into Al-MCM-41 prepared via ship-in-a-bottle methodology. The samples were fully characterized by diffuse reflec...
Kinetic and mechanistic aspects of the direct photodegradation of atrazine, atr...
Azenha, M. E. D. G.; Burrows, H. D.; L., M. Canle; Coimbra, R.; Fernández, M. I.; García, M. V.; Peiteado, M. A.; Santaballa, J. A.Atrazine (1), Atraton (2) and Ametryn (3) are photodegraded upon 254 nm irradiation, yielding 2-OH-atrazine (4) as a photoproduct. Dealkylation products are also generated, and 4-ethylamino-6-isopropylamino-(1,3,5)-triazine was also found as a photoproduct of 3. The main photoreaction is proposed to be an addition-elimination, yielding 4, which subsequently photodegrades. The ease of photodegradation depends on...
Photooxidation of 4-chlorophenol sensitised by iron meso-tetrakis(2,6-dichloro-...
Silva, Eliana; Pereira, Mariette M.; Burrows, Hugh D.; Azenha, M. E.; Sarakha, Mohamed; Bolte, MichèleThe photosensitised degradation of 4-chlorophenol (4-CP) by iron meso-tetrakis(2,6-dichloro-3-sulfophenyl)porphyrin (FeTDCPPS) has been studied in aerated aqueous solution, and is shown to lead to formation of p-benzoquinone (BQ) and p-hydroquinone (HQ) as main photoproducts. In deaerated solution no p-benzoquinone was formed. The photolysis products were identified by high performance liquid chromatography (HP...
The characterisation by luminescence spectroscopy of uranium(VI) incorporated i...
Azenha, M. E. D. G.; Miguel, Maria da Graça; Formosinho, S. J.; Burrows, H. D.Luminescence spectroscopy of solids at 77 K has been used to characterise the uranium(VI) species incorporated into [alpha]-alumina, [gamma]-alumina and zeolites Y and ZSM-20 by adsorption from solution and into ZSM-5 by chemical synthesis. With uranyl adsorbed from nitrate solutions onto [alpha]- and [gamma]-aluminas, the luminescence measurements show the dominant uranium species is schoepite, UO3·xH2O, in ag...
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