Synthesis of an azo-Mn(II) complex with mild pH control using a microfluidic device

This study describes the synthesis of an azo-Mn(ii) complex requiring an accurate pH control. The reaction conditions for the delicate azo-Mn(ii) complex could be precisely controlled using a microfluidic device. The microfluidic method showed the following advantages over the conventional method: the concentration of the pH-control reagent was reduced (1/15), the reaction time was remarkably decreased from 4 h to less than 1 s, and the reaction temperature was lowered from 40 to 23 °C. Moreover, the microfluidic device suppressed the oxidation of the compound and did not require cooling to remove the heat of reaction. In addition, the conventional method uses harsh pH control, whereas the microfluidic device permits mild pH control.