Low temperature route towards new materials: solvothermal synthesis of metal chalcogenides in ethylenediamine

Solid state reactions occur among solid reactants and are characterized by slow nucleation and diffusion processes. Thus, high temperature is often required to promote the reactions to proceed at an appropriate rate. Kinetic control and mechanistic study of these systems are usually very difficult. One has little control in rational design and prediction of the structures coming out of the reactions. High temperature products are often limited to the thermodynamically most stable phases. The recent development in soft synthesis of metal chalcogenides has been motivated and stimulated by the tremendous progress in the crystal engineering of organic and coordination compounds via molecular building-block approaches. The hope is that by turning down the temperature, the solid state synthesis may proceed in a more controlled and predictable manner. Much research has been carried out in exploration and investigation of various soft synthetic techniques. In this article, we will focus only on the recent development in solvothermal synthesis using ethylenediamine as a reaction medium.