2,2,2-Cryptand 23978-09-8 4,7,13,16,21,24-Hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane Cryptand 222 Cryptate 222 Cryptating agent 222 Kriptofix 222 Kryptofix 222 Kryptofix Merck 222 NSC264495