Molecular capsules based on cucurbit[5]uril encapsulating "naked" anion chlorine

Four barrel-shaped artificial molecular capsules based on cucurbit[5] uril, [K-4(C30H30N20O10)(2)(HCONH2)(2)(H2O)(2)Cl-2] Cl-2 center dot CH3OH center dot 17.5H(2)O ( 1), {[Ba-2(C30H30N20O10) Cl](NO3)(H2O)(5)} Cl-2 center dot 2H(2)O ( 2), [Cd(C30H30N20O10) Cl-2](H3O)(2)(2+) CdCl42- center dot 2CH(3)OH(2)center dot 4H(2)O (3), and {[La(C30H30N20O10) Cl] LaCl(H2O)(9)} Cl-4 center dot HCl center dot 7H(2)O ( 4) were synthesized and structurally characterized by single-crystal X-ray diffractions. The crystal structure of these compounds show that chlorine anions were encapsulated in cucurbit[ 5] uril to form open or closed molecular capsules. 1 forms a novel one-dimensional (1D) polycationic chain in the solid state and the other three molecular capsules crystallize in isolated molecules.