Structural Diversity in 4,4‘-Trimethylenedipyridine−zinc phosphite Hybrids: Incorporation of Neutral Guest Molecules in Hybrid Materials

Six new zinc phosphite hybrids are prepared under a variety of reaction conditions from the primary building
blocks, trimethylenedipyridine, zinc acetate, and phosphorous acid. Neutral guest molecules are incorporated into
several of the structures. Under hydrothermal conditions at 130 °C, an anionic framework structure, 1, templated
on trimethylenedipyridinium, is obtained while a neutral ladder structure, 2, is formed at room temperature. These
reactions are done at an initial pH of 4.7−5.0. When the reaction is done at an initial pH of 7.8−8.0, a neutral
layered motif is obtained with 1,3-dipyridylpropane pillars and neutral guests in the interstitial space. Structures
with water, phenol, and catechol as the guests, compounds 3, 4, and 5, respectively, are reported. The use of
catechol as a template results in the breakup of the ZnPO sheet structure common to both 3 and 4. When amino
acids, including alanine, were added to the reaction medium, a neutral three-dimensional framework, 6, is obtained
with no incorporation of the potential template. The syntheses and structures of these new materials are reported.