The distinct research
areas related to CO
2
capture and
mechanochemistry are both highly attractive in the context of green
chemistry. However, merger of these two areas,
i.e.
, mechanochemical CO
2
capture, is still in an early stage
of development. Here, the application of biguanidine as an active
species for CO
2
capture is investigated using both solution-based
and liquid-assisted mechanochemical approaches, which lead to a variety
of biguanidinium carbonate and bicarbonate hydrogen-bonded networks.
We demonstrate that in solution, the formation of the carbonate vs
bicarbonate networks can be directed by the organic solvent, while,
remarkably, in the liquid-assisted mechanochemical synthesis employing
the same solvents as additives, the selectivity in network formation
is inversed. In general, our findings support the view of mechanochemistry
not only as a sustainable alternative but rather as a complementary
strategy to solution-based synthesis.