BCN-exo-PEG7-maleimide, an ADC Linker, has seven PEG units and includes the lyophilic bidentate macrocyclic ligand BCN for further synthesis of macrocyclic complexes. In click chemistry, it reacts with azide-containing molecules to form stable triazoles without the need for catalysts. The compound's maleimide group (-Maleimide) is prone to degradation in aqueous media and has applications in drug delivery studies.