Synthesis and crystallography of 2,3,3,5,6,6-hexamethyl-3,6-dihydropyrazine hexahydrate and 3-amino-3-methyl-2-butanone hydrochloride

Conformational polymorphism of 1,8-dipyridylnaphthalene and encapsulation of chains of fused cyclic water pentamers in a hydrophobic crystal environment

“…22 By contrast, fused pentameric water rings are rarely found in less hydrophilic crystal environments and only two examples have been reported to date. Timberlake et al obtained sheets consisting of T5(2) water clusters stabilized by hexamethyl-3,6-dihydropyrazine 23 and Groth found that adjacent T5(2) water channels form within a dihydrothiazolopyridinone host. 24 Both organic hosts are considerably less hydrophobic than 1,8-dipyridylnaphthalene, 1, and more importantly, both structures do not have isolated water channels.…”