Metal-Assisted and Solvent-Mediated Synthesis of Two-Dimensional Triazine Structures on Gram Scale

Covalent triazine
frameworks are an emerging material class that
have shown promising performance for a range of applications. In this
work, we report on a metal-assisted and solvent-mediated reaction
between calcium carbide and cyanuric chloride, as cheap and commercially
available precursors, to synthesize two-dimensional triazine structures
(2DTSs). The reaction between the solvent, dimethylformamide, and
cyanuric chloride was promoted by calcium carbide and resulted in
dimethylamino-s-triazine intermediates, which in
turn undergo nucleophilic substitutions. This reaction was directed
into two dimensions by calcium ions derived from calcium carbide and
induced the formation of 2DTSs. The role of calcium ions to direct
the two-dimensionality of the final structure was simulated using
DFT and further proven by synthesizing molecular intermediates. The
water content of the reaction medium was found to be a crucial factor
that affected the structure of the products dramatically. While 2DTSs
were obtained under anhydrous conditions, a mixture of graphitic material/2DTSs
or only graphitic material (GM) was obtained in aqueous solutions.
Due to the straightforward and gram-scale synthesis of 2DTSs, as well
as their photothermal and photodynamic properties, they are promising
materials for a wide range of future applications, including bacteria
and virus incapacitation.