The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calciu...The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calcium L-threonate with oxalic acid and superfluous manganese oxide at 80℃for c ertain time.The composition of the n ew compound was determined by chemical and elemental analyses and its formu la fits Mn (C 4 H 7 O 5 ) 2 ·H 2 O,the IR spectra indicated that Mn 2+ in the compound coordinates to oxygen atom of the carboxyl group,while th e proton of the carboxyl group is dissociated,i t was assumed that the coordination n umber of Mn 2+ was 4.The results of TG-DTG showed that the compound have fairish stability,the intermediate and final product of the thermal de-composition of the compound are Mn (C 4 H 7 O 5 ) 2 and MnO 2 ,respectively.The constant volume combustion energy of the compound,Δ c E,were determined by a precise rotating-bomb calorimeter at 298.15K,it was(-3384.30±1.21)kJ·mol -1 ,its standard enthalpy of Combustio n,Δ c H m ,and standard enthalpy of formation,Δ f H m ,were calculated.They are(-3383.07±1.21)kJ·mol -1 and(-2571.68±1.63)kJ·mol -1 ,respectively.展开更多
文摘The pink powder of manganese L-threonate was obtained by extracting with alcohol the concentrated solution derived from the reaction between L-threonic acid solution prepared by double decomposition reaction of calcium L-threonate with oxalic acid and superfluous manganese oxide at 80℃for c ertain time.The composition of the n ew compound was determined by chemical and elemental analyses and its formu la fits Mn (C 4 H 7 O 5 ) 2 ·H 2 O,the IR spectra indicated that Mn 2+ in the compound coordinates to oxygen atom of the carboxyl group,while th e proton of the carboxyl group is dissociated,i t was assumed that the coordination n umber of Mn 2+ was 4.The results of TG-DTG showed that the compound have fairish stability,the intermediate and final product of the thermal de-composition of the compound are Mn (C 4 H 7 O 5 ) 2 and MnO 2 ,respectively.The constant volume combustion energy of the compound,Δ c E,were determined by a precise rotating-bomb calorimeter at 298.15K,it was(-3384.30±1.21)kJ·mol -1 ,its standard enthalpy of Combustio n,Δ c H m ,and standard enthalpy of formation,Δ f H m ,were calculated.They are(-3383.07±1.21)kJ·mol -1 and(-2571.68±1.63)kJ·mol -1 ,respectively.
