Preparation and spectroscopic characterization of two manganese(II)semiquinone complexes - Barreto, Wagner José; Barreto, Sônia Regina Giancoli; Kawano, Yoshio; Oliveira, Luiz Fernando Cappa de; Di Mauro, Eduardo; Paschoal, Fabiana Maria Monteiro (Monatshefte fur Chemie, 2003)