Hexamethylenediamine cyclodextrin connection of carbon chain is longer than the ethylenediamine cyclodextrin,under certain conditions,hexamethylenediamine cyclodextrin primary amine groups have less space steric hindrance and larger space than an ethylenediamine cyclodextrin primary amine, easier and with larger steric hindrance of carboxylic acid, ester, acid, aldehyde, ketone, halogenated under mild conditions, such as key chain.