The present invention pertains to novel thiocycloheptyne derivatives of general formula (I): and in particular to thiacycloalkynesulfoimine derivatives and their synthesis. The invention also relates to the use of the novel thiocycloheptyne derivatives in coupling reactions with linkers and drugs. The invention further relates to the use of the novel thiocycloheptynes in bioorthogonal (copper-free) click reactions. The invention further pertains to the use of the novel thiocycloheptyne derivatives in the generation of advanced multifunctional drug delivery systems (drug-loaded) nanoparticles.