A tetranuclear Mn(Ⅳ) complex \{\[L\-4Mn\-4O\-6\]\}(ClO\-4)\-4\52H\-2O (L=tacn)was synthesized from Mn(CH\-3COO)\-2\54H\-2O, tacn and NaClO\-4 and characterized by XRD. The compound crystallizes in monoclinic system, ...A tetranuclear Mn(Ⅳ) complex \{\[L\-4Mn\-4O\-6\]\}(ClO\-4)\-4\52H\-2O (L=tacn)was synthesized from Mn(CH\-3COO)\-2\54H\-2O, tacn and NaClO\-4 and characterized by XRD. The compound crystallizes in monoclinic system, space group P2\-1/n , with a =2.133 5(6) nm, b =1.138 7(3) nm, \{ c =\}\{2.178 8(6) nm\}, β =67.40(3)°, V =4.928(2) nm 3 , Z =4, R =0.062 0. Magnetic investigations reveal a weak ferromagnetic property with J =8.8 cm -1 .展开更多
The kinetics and mechanism of lactic acid oxidation in the presence of Mn(II)and Ce(IV)ions by chromic acid were studied spectrophotometrically.The oxidation of lactic acid by Cr(VI)was found to proceed in two measura...The kinetics and mechanism of lactic acid oxidation in the presence of Mn(II)and Ce(IV)ions by chromic acid were studied spectrophotometrically.The oxidation of lactic acid by Cr(VI)was found to proceed in two measurable steps,both of which gave pyruvic acid as the primary product in the absence of Mn(II).2Cr(VI)+2CH3CHOHCOOH→2CH3COCOOH+Cr(V)+Cr(III)Cr(V)+CH3CHOHCOOH→Cr(III)+CH3COCOOH The observed kinetics was explained due to the catalytic and inhibitory effects of Mn(II)and Ce(IV)on the lactic acid oxidation by Cr(VI).The reactivity of lactic acid depends upon the experimental conditions.It acts as a two-or three-equivalent reducing agent in the absence or presence of Mn(II).It was examined that Cr(III)products resulting from the direct reduction of Cr(VI)by three-equivalent reducing agents.The oxidation of lactic acid follows the complex order kinetics with respect to [lactic acid].The activation parameters Ea,ΔH#,and ΔS# were calculated and discussed.展开更多
文摘A tetranuclear Mn(Ⅳ) complex \{\[L\-4Mn\-4O\-6\]\}(ClO\-4)\-4\52H\-2O (L=tacn)was synthesized from Mn(CH\-3COO)\-2\54H\-2O, tacn and NaClO\-4 and characterized by XRD. The compound crystallizes in monoclinic system, space group P2\-1/n , with a =2.133 5(6) nm, b =1.138 7(3) nm, \{ c =\}\{2.178 8(6) nm\}, β =67.40(3)°, V =4.928(2) nm 3 , Z =4, R =0.062 0. Magnetic investigations reveal a weak ferromagnetic property with J =8.8 cm -1 .
文摘The kinetics and mechanism of lactic acid oxidation in the presence of Mn(II)and Ce(IV)ions by chromic acid were studied spectrophotometrically.The oxidation of lactic acid by Cr(VI)was found to proceed in two measurable steps,both of which gave pyruvic acid as the primary product in the absence of Mn(II).2Cr(VI)+2CH3CHOHCOOH→2CH3COCOOH+Cr(V)+Cr(III)Cr(V)+CH3CHOHCOOH→Cr(III)+CH3COCOOH The observed kinetics was explained due to the catalytic and inhibitory effects of Mn(II)and Ce(IV)on the lactic acid oxidation by Cr(VI).The reactivity of lactic acid depends upon the experimental conditions.It acts as a two-or three-equivalent reducing agent in the absence or presence of Mn(II).It was examined that Cr(III)products resulting from the direct reduction of Cr(VI)by three-equivalent reducing agents.The oxidation of lactic acid follows the complex order kinetics with respect to [lactic acid].The activation parameters Ea,ΔH#,and ΔS# were calculated and discussed.
