Replacing hydrogen bonds with coordinate covalent bonds in coordination networks.

摘要

The overall theme of the dissertation is that metal ions such as silver(I) can replace H+ in hydrogen bonded organic frameworks. Because organic solids have been extensively studied, we can insert metal ions into the supramolecular assemblies, thus creating predictable coordination solids of varying dimensions. One example of an organic solid tested involves the organic compounds terephthalic and isophthalic acids. These dicarboxylic acids have previously been shown to self-assemble into tape-like structures via hydrogen bonding, with neighboring dicarboxylic acids located at angles of 180° and 120° respectively. By substituting the hydrogen bonds with coordination metal-ligand bonds similar assemblies are formed. Other examples include the sulfur based ligand 1,3-dithiane which is similar in structure to isophthalic acid. Because dithinae is saturated and has an extra lone pair of electrons on the sulfur atoms, in this case there is a possibility of one-, two-, three-, or four-fold connectivity to each ligand. The effect of the counterion on the overall upon reaction with a variety of silver salts is discussed. The structures of unsaturated nitrogen-based bifunctional ligands pyrimidine, 4,6-dimethylpyrimidine and 2-hydroxy-4,6-dimethylpyrimidine in combination with zinc(II) chloride are also reported. Finally, the effect of chain length of 5-alkynylpyrimidine on coordination compounds analogous to their organic counterparts is demonstrated. It will be shown that both chain length and anion will influence the supramolecular assembly.