The Design And Synthesis Of Pyrazinyl Host Molecules For Supramolecular Structure Studies

Hydrogen bond plays an important role in constructing many of supramolecular structures. We designed and prepared special supramolecular radical molecules in which there are some donor- and acceptor-atoms for growing the multipoint supramolecular crystallization purposes. Using bridge group is the first important thing to build supramolecular structures because the multidimensional supramolecular network is constructed on the bones of organic compounds. Pyrazinyl ring is one of the simplest bridge groups. Being the electrons effect of two nitrogen atoms of pyrazinyl, the hydrogen atoms have some acidity, which makes itself more actively as donor in constructing topology array. The carboxamide group, as the basic unit of protein in nature's lives, has good water-solubility. Sometimes the carboxamide groups may combine each other through hydrogen bonds that are significative for structure steadily.In this thesis, a total of 11 novel crystals have been grown by the self-assembly with water guest, anion guest as well as transition metal cations through the hydrogen-bonding and coordination interactions. The factors governing the framework formations of these H-bonding supramolecule and complexes have been discussed. This thesis includes three parts as follows:1. A series of new pyrazine carboxamide compounds that have been designed and prepared contain the more flexible spacer of alkyl or azaalkyl. The trans-2-(2-phenylethenyl)pyrazine ligand was been synthesized. Above all have characterized by IR, elemental analysis and X-ray crystallography.2. By using the azaalkyl pyrazine carboxamide hosts, we grown three special supramolecular network crystals self-assembled with water guest and anion guest, respectively. One self-assembled with water guest as an excellent water-nano-tube through hydrogen bonds. Another constructed water tape guest with chair conformation fused-watersix- rembered. And the other combained with NO₃^- anion guest through NO₃^-…π and H…π interactions. All of them are stabilization at room temperature. The research has shown that the pyrazinyl is excellent group for self-assembly system by its H atoms self-assembled ability. Also, we use water solvent as the multipoint supramolecular synthon, as regards just the linking of waters...