Described is the behavior of self-assembled capsules held together by hydro
gen bonds. The capsules can be spherical or cylindrical and they reversibly
encapsulate suitable guest species in organic solvents. Selectivity to mol
ecular shape and length leads to well-defined complexes of two different gu
ests within the capsule. These lead to their use as catalysts and to the sy
nthesis of multiparticle assemblies. The use of charged guest species for a
ssembly characterization in the gas phase is also described.