Well-Resolved, New Water Morphologies Obtained by Modification of the Hydrophilic/Hydrophobic Character and Shapes of the Supporting Layers

The planar coordination complexes [Ag2L2] (L = ophen or obpy, where Hophen = 1H-[1,10]phenanthrolin-2-one
and Hobpy = 1H-[2,2‘]bipyridinyl-6-one) contain both hydrophilic and hydrophobic functional groups. Crystallization
of these structurally related complexes in an aqueous medium gives [Ag2(ophen)2]2·6H2O (1), [Ag2(obpy)2]3·18H2O
(2), and [Ag2(obpy)2]2·14.5H2O (3). Novel water morphologies are observed in these crystalline hydrates, similar
2D metal−organic layers in which the planar [Ag2L2] complexes as building blocks are stacked alternately together
and provide hydrogen bond acceptor sites (O atoms) for anchoring 1D water chains or 2D water layers on their
surfaces. In the wavelike metal−organic framework of 1, the wide hydrophobic region renders the formation of 1D
water tapes containing four- and six-membered water rings, whereas more complex 2D water layers are sandwiched
in 2 and 3, owing to the fact that the surfaces of the supporting layers are more hydrophilic than 1.