FU Lijuan, LIU Yingying, LU Houfang, et al. Reactivity of hydroxyls and stability of DBU/C3-alcohol/CO2 ionic compounds[J]. CIESC Journal, 2015, (10): 4163-4169. DOI: 10.11949/j.issn.0438-1157.20150162.
DOI:
FU Lijuan, LIU Yingying, LU Houfang, et al. Reactivity of hydroxyls and stability of DBU/C3-alcohol/CO2 ionic compounds[J]. CIESC Journal, 2015, (10): 4163-4169. DOI: 10.11949/j.issn.0438-1157.20150162.DOI:
Reactivity of hydroxyls and stability of DBU/C3-alcohol/CO2 ionic compounds
The DBU/C3-alcohol/CO2 ionic compounds were synthesized by reacting the C3-alcohols
namely 1-propanol
2-propanol
1
2-propanediol
1
3-propanediol and glycerol with CO2 and 1
8-diazabicycloundec-7-ene (DBU)
respectively. The composition and structure of them were characterized by FT-IR
NMR and TG. The reactivity of the hydroxyls at different position in C3-alcohol and the steric effect in polyols were studied. The results showed that the reactivity of the primary hydroxyl of 1-propanol was higher than the secondary hydroxyl of 2-propanol in the reaction of DBU+C3-alcohol+CO2. For the diols
the steric hindrance and the electronic effect significantly lowered the activity of the second hydroxyl
and such interaction in 1
2-diols was stronger than that of 1
3-diols. For the DBU+glycerol+CO2 system
the main ionic compound was formed by reacting with only one of the primary hydroxyl in glycerol. The second most abundant product was formed by reacting both of the primary hydroxyls in glycerol. However
the complete conversion of all three hydroxyls seemed not possible due to the high steric hindrance effect.