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Reported here is the preparation and property of 2D coordination networks composed of rodlike ligands with ethylene glycol side chains (1). Two 2D coordination networks, {[Co(1)2(H2O)2](NO3)2·1.5H2O}n and {[Ni(1)2(H2O)2](NO3)2·1.5H2O}n, have been synthesized and characterized by single-crystal X-ray diffraction, TG, DSC, UV-vis spectroscopy, and magnetic measurements. The structural analyses clarified that infinite 1D hydrogen-bond arrays composed of ethylene glycol chains contribute to the stabilization of 2D coordination frameworks, keeping the environment of substitution-active metal sites unchanged. They are more stable than a similar square-grid coordination network that does not possess an ethylene glycol chain on the ligand. We also succeeded in the direct observation of a reversible apical-ligand-exchange reaction at the cobalt(ll) and nickel(ll) ions in a single-crystal-to-single-crystal fashion because of the considerable stability as well as moderate flexibility of the framework. The cobalt-containing coordination network crystal showed chromic behavior depending on temperatures. Crystallographic and spectroscopic studies revealed that the color change of the crystal was attributed to the ligand-exchange process between H2O and a NO3 anion on the cobalt metal. Magnetic measurements indicated weak antiferromagnetic nearest-neighbor spin coupling between cobalt(ll) ions. [ABSTRACT FROM AUTHOR]

The title complex, [Ni(C3H2O4)(C12H8N2)(H2O)2]·3H2O, displays a distorted octa­hedral NiN2O4 coordination geometry, formed by a malonate dianion, a 1,10-phenanthroline ligand and two trans water mol­ecules. The Ni atom and one O atom, the latter from a solvent water mol­ecule, are located on twofold axes of symmetry. The crystal structure is stabilized by extensive O—H⋯O hydrogen-bonding inter­actions. [ABSTRACT FROM AUTHOR]

Mol­ecules of the title compound, C23H24N4O, are linked into chains by O—H⋯N hydrogen bonds and C—H⋯π inter­actions. Aromatic π–π stacking inter­actions exist between chains. [ABSTRACT FROM AUTHOR]

In the title compound, C24H34O8, a strong intra­molecular O—H⋯O hydrogen bond is formed between the OH substituent of salicyaldehyde and the aldehyde O atom. [ABSTRACT FROM AUTHOR]