Hydrogen Bonding in Supramolecular Crystal Engineering

The term crystal engineering was first used by Schmidt [1] in coimection with the research on solid state photodimerization reactions on the basis of topochemical principle, which correlated the solid state reactivity of monomers with their crystal 

Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, China e-mail zhengqy iccas.ac.cn 

Li and L. Wu (eds.). Hydrogen Bonded Supramolecular Structures, Lecmie Notes in Chemistry 87, DOI 10.1007/978-3-662-45756-6 3 

---

Another major area of CSD-based research is the supramolecular stmctural organization and crystal engineering, and particularly the role of hydrogen bonding in the solid state. Although fhe initial incentive came from biomolecular chemistry, fhe results are equally important for inorganic, organometallic, and polymeric materials. 

The crystal structures of six 3,6-diaryl-l,2,4,5-tetrazines have been determined and their molecular packing has been compared to the supramolecular architecture observed in related carboxylic acid dimers. In the tetrazines, covalent N-N bonds are considered to replace the intermolecular O-H- - -O hydrogen bonds of the carboxylic acids. In the system investigated, the covalent six-membered ring of the tetrazine was an appropriate replacement for the carboxylic acid synthon. This apparent interplay between molecular and supramolecular units may have applications in the crystal engineering of new materials (Figure 1) <2003HCA1205>. 

Braga, D., Maini, L., Polito, M., Grepioni, F. (2004), Hydrogen bonding interactions between ions A powerful tool in molecular crystal engineering, Supramolecular Assembly Via Hydrogen Bonds II, 111, 1-32. 

Mak TCW, Xue F (2000) Supramolecular rosette ribbon construded from guanidium and hydrogen carbonate ions in the crystal engineering of hydrogen-bonded networks. J Am Chem Soc 122 9860... 

---