Three related benzoannelated diazapolyether macrocycles: effects of macrocycle ring size and position of benzo groups on hydrogen bonding of the amine H atoms.

The benzoannelated diazapolyether macrocycles 6,7,9,10,17,18-hexahydro-5H,11H-8,16,19-trioxa-5,11-diazadibenzo[a,g]cyclopentadecene, C(18)H(22)N(2)O(3), (I), 6,7,9,10,12,13,20,21-octahydro-5H,14H-8,11,19,22-tetraoxa-5,14-diazadibenzo[a,g]cyclooctadecene, C(20)H(26)N(2)O(4), (II), and 6,7,9,10,17,18,20,21-octahydro-16H,22H-5,8,11,19-tetraoxa-16,22-diazadibenzo[a,j]cyclooctadecene 0.3-hydrate, C(20)H(26)N(2)O(4) x 0.304H(2)O, (III), show different patterns of hydrogen bonding. In (I), the amine H atoms participate only in intramolecular hydrogen bonds with ether O atoms. In (II), the amine H atoms form intramolecular hydrogen bonds with the phenoxy ether O atoms and intermolecular hydrogen bonds with alkyl ether O atoms in an adjacent molecule, forming a chain linking the macrocycles together via an R(2)(2)(10) motif. Molecules of (II) were found on a crystallographic twofold axis. In (III), the amine H atoms participate in a hydrogen-bond network with adjacent ether O atoms and with a water molecule [having a partial occupancy of 0.304 (6)] that links the molecules together via a C(2)(2)(7) motif.