We report the systematic synthesis and thorough characterization of a discrete organotin sulfide cavitand, [(R4Sn12S20)-Sn-B] {1, R-13 = 1,5-bis[(E)-2-(4-methylpentan-2-ylidene)hydrazinyl]naphthalene}, which readily Undergoes a unique transformation into a stable, rugby-ball-like capsule, [(R3Sn6S8)-Sn-B][(SnCl3)(2)] (2), upon addition of a protic acid. DMF molecules are embedded within the cavities of both compounds by hydrogen-bonding interactions, spotlighting the title compounds with respect to molecular containment.