Properties of (m-Oxo)di-iron Complexes and Catalytic Activity Toward Cyclohexane Oxidation
نویسندگان
چکیده
Neste artigo são apresentadas a síntese e a caracterização de dois compostos binucleares de ferro, os quais contêm uma ponte m-oxo. Os compostos [(SO 4 )(L5)Fe(m-O)Fe(L5)(SO 4 )]•6H 2 O, 1, e [Cl(L5)Fe(m-O)Fe(L5)Cl]Cl 2 •2H 2 O, 2, foram obtidos nas reações entre 1-(bis-piridin-2-ilmetilamino)-3-cloropropan-2-ol (L5) e os sais FeSO 4 •7H 2 O e FeCl 3 •6H 2 O, respectivamente. Os espectros eletrônicos dos complexos apresentam absorções somente na região do ultravioleta, sendo que a análise eletroquímica revelou que, após a formação da espécie FeFe, a unidade binuclear do composto 1 é mais estável do que a do composto 2. Os ligantes monodentados (sulfato e cloreto) exercem influência sobre os parâmetros Mössbauer determinados para 1 e 2, particularmente sobre os desdobramentos de quadrupolo. Os compostos foram empregados como catalisadores em reações de oxidação do cicloexano, usando H 2 O 2 e t-BuOOH como oxidantes em uma razão substrato:oxidante:catalisador de 1000:1000:1. Os resultados indicam que o composto 2 é um catalisador mais eficiente que o composto 1.
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