resumo
Compounds with trihexyl(tetradecyl)phosphonium (THTP) cations and first row transition metal-substituted Keggin polyoxoanions were synthesised, having the general formula (THTP)(m)[PW11O39M(H2O)] with M = Fe, Co, Mn and m = anion charge. All compounds were characterized by spectroscopic and analytical techniques. These studies indicated that both the polyoxometalates and the cations are present in the new compounds without major alterations. All compounds are coloured liquids at room temperature and are stable up to ca. 300 degrees C. Studies conducted at low temperatures point to a solidification process at about -25 degrees C for the Fe and Co materials. Electrochemical measurements were performed for (THTP)(4)[PW11O39Fe(H2O)] on a functionalized glassy carbon electrode. This work was complemented by the preparation and characterization of compounds with the anions [PW11O39](7-) and [P2W20O70(H2O)(2)](10-), which were also liquids at room temperature.
palavras-chave
KEGGIN-TYPE POLYOXOTUNGSTATES; INORGANIC HYBRID MATERIALS; HYDROGEN-PEROXIDE; ELECTROCHEMICAL PROPERTIES; 12-TUNGSTOPHOSPHORIC ACID; ELECTROCATALYTIC ACTIVITY; 12-PHOSPHOTUNGSTIC ACID; SELECTIVE OXIDATION; H2O2 REDUCTION; WELLS-DAWSON
categoria
Chemistry
autores
Santos, FM; Magina, SP; Nogueira, HIS; Cavaleiro, AMV
nossos autores
Ana Maria Vieira Silva Viana Cavaleiro
Professor Catedrático
Filipe Miguel de Almeida Marques dos Santos
Bolseiro de pós-Doutoramento
Helena Isabel Seguro Nogueira
Professor Auxiliar com Agregação
Sandra Pereira Magina
Investigadoragradecimentos
Thanks are due to the University of Aveiro and CICECO for financial support. This work was developed in the scope of the project CICECO-Aveiro Institute of Materials (Ref. FCT UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when applicable co-financed by FEDER under the PT2020 Partnership Agreement. F. M. Santos acknowledges FCT for his PhD grant SFRH/BD/40857/2007. The authors thank Master Maria Celeste Azevedo for her invaluable help in conducting additional thermal studies.