The author of 《Synergistic cooperation of bi-active hydrogen atoms in protic carboxyl imidazolium ionic liquids to push cycloaddition of CO2 under benign conditions》 were Wang, Tengfei; Zhu, Xinrui; Mao, Lemin; Liu, Yi; Ren, Tiegang; Wang, Li; Zhang, Jinglai. And the article was published in Journal of Molecular Liquids in 2019. Formula: C6H11BrO2 The author mentioned the following in the article:
Nine protic carboxyl imidazolium ionic liquids were synthesized. Then, they were employed to catalyze the chem. fixation of carbon dioxide (CO2) and propylene oxide leading to propylene carbonate in the absence of co-catalyst and organic solvent. HCPImBr presents the best catalytic activity with the product yield of 92% under reaction temperature 120°C, CO2 initial pressure 1.5 MPa, catalyst amount 0.5 mol%, and reaction time 2.0 h. Even if the reaction temperature and CO2 initial pressure are decreased to 80°C and 1.0 MPa, resp., the 85% of product yield would be kept with the 1.0% catalyst dosage along with 12.0 h. With the exception of the most optimal reaction conditions, generality, and recyclability of HCPImBr are also investigated. More importantly, the reaction mechanism is investigated by the d. functional theory, which is the first time to report the mechanism for protic carboxyl imidazolium ionic liquids The catalytic activity of ionic liquids would be further improved with the reasonable combination of cation and anion. In the part of experimental materials, we found many familiar compounds, such as Ethyl 4-bromobutyrate(cas: 2969-81-5Formula: C6H11BrO2)
Ethyl 4-bromobutyrate(cas: 2969-81-5) belongs to bromides. A variety of minor organobromine compounds are found in nature, but none are biosynthesized or required by mammals. Organobromine compounds have fallen under increased scrutiny for their environmental impact.Formula: C6H11BrO2
Referemce:
Bromide – Wikipedia,
bromide – Wiktionary