Fixierung von CO2 durch Pyrazolylborat‐Zink‐Hydroxid‐Komplexe

Fixation of CO₂ by Pyrazolylborate‐Zinc‐Hydroxide Complexes The reversible uptake of CO₂ by Tp*Zn‐OH complexes in alcoholic solutions with formation of Tp*Zn‐alkylcarbonate complexes was subjected to a comparative study. Its rate and the stability of its products depend on (1) the substituents in the 3‐positions of the pyrazolylborates (phenyl ≈ 3‐pyridyl ? t‐butyl), (2) the alcohol (CH₃OH > C₂H₅OH). Traces of water seem to be essential for the formation of the Tp*Zn‐alkylcarbonates. In solution these are only stable in the presence of CO₂. Two new alkylcarbonate complexes were obtained and characterized by structure determinations.