Isolation and Crystal Structure Determination of Piperazine Dicarbamate Obtained from a Direct Reaction between Piperazine and Carbon Dioxide in Methanol

Abstract

Figure S1. Schematic description on the reversible formation of various piperazine derivatives in aqueous solution.S1 The double arrows involve CO2 addition or removal, and the single arrows do proton transfers. Figure S2. Crystallization setups for PZ carbamate. CO2 or N2 respectively filled in a balloon was introduced to the reaction media contained in a sealed vial. When CO2 was introduced with N2, larger crystals could be obtained. Figure S3. FT-IR spectra of (a) PZ and (b) a PZ-dicarbamate salt. Figure S4. PXRD patterns for PZ and a PZ-dicarbamate salt. Figure S5. TGA curves measured under nitrogen for (a) a PZ-dicarbamate salt and (b) an AMP carbamate salt. The black lines are for (a) PZ and (b) AMP, and the colored lines are for (a) the PZ-dicarbamate salt and (b) the AMP carbamate salt, respectively. The temperature-increasing rates are 5 and 10°C/min respectively in (a) and (b). Table S1. Crystal and refinement data for 1. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.