The present disclosure relates generally to new bifunctional linchpins that react selectively with cysteine residues to invoke cyclization while concurrently introducing a radiometal chelation ligand or silicon-based fluoride acceptor (SiFA) motif.

Covalent organic framework compositions are provided that incorporate the nitrogen atoms of a squaramide functionality into the covalent organic framework structure while reducing or minimizing the number of nitrogen atoms in the minimum ring framework path of the covalent organic framework. Methods for forming such covalent organic framework compositions are also provided.

Covalent organic framework compositions are provided that incorporate the nitrogen atoms of a squaramide functionality into the covalent organic framework structure while reducing or minimizing the number of nitrogen atoms in the minimum ring framework path of the covalent organic framework. Methods for forming such covalent organic framework compositions are also provided.