text: The internal cavity of a carcerand can be as large as 1700 Å (1.7 nm) when six hemicarcerands form a single octahedral compound. This is accomplished by dynamic covalent chemistry in a one-pot condensation of 6 equivalents of a  and 12 equivalents of ethylene diamine with trifluoroacetic acid catalyst in chloroform at room temperature followed by reduction of the imine bonds with sodium borohydride.