The differentiated recognition of Ag1 and Hg11 can be achieved with the pentaleno crown ethers 1 by variation of the cavity through the reversible trithia-diazapentalene–trithiotriuret redox system (1⇌2). These compounds were obtained in a one-pot reaction of trithiadiazapentalenes with diamino polyethers of different chain lengths. n = 1–3, R = CH3, CH2C6H5