High pressure chemical method refers to the method for studying chemical reaction and its application under high pressure (above 10000 bar). High pressure chemistry mainly studies solid and liquid. The problem studied involves the relationship between pressure and energy. It is generally believed that the higher the pressure the object is subjected to, the energy converted by the force is enough to cause the deformation of the electron orbit and produce chemical reaction. The study of high-pressure chemical methods has theoretical and practical significance for understanding and transforming nature; In the development of new materials, many special materials are synthesized or made by high temperature and high pressure methods. At 2500 ℃ and 200000 atmospheric pressure, graphite can be transformed into diamond. Because this pressure actually changes the shape of the electron orbit, new varieties of materials can be made. For example, a new variety of silicon oxide can be made now. It is different from ordinary silicon oxide, and its reaction rate with hydrofluoric acid is significantly reduced. [1]
At present, the high pressure that the laboratory can reach has exceeded 500000 bars, while the natural pressure can reach 3.5 million bars. According to the relationship between energy and chemical reaction, pressure can be divided into three main ranges. ① In the range of 1 bar to 104 bar, the normal low-pressure chemical behavior is dominant, and the usual valence state and coordination rule have only a small deviation. ② In the range of 104 bar to 109 bar, the increased energy due to compression is comparable to the chemical bond energy, resulting in the deformation of the outer electronic orbit, changes in the characteristics of atoms and molecules, and recombination. ③ Above about 109 bar, the electron delocalization is complete, and the substance is composed of a mixture of ions and electrons, so the chemical bond has lost its meaning. Most rocks and minerals in nature are formed under high temperature and pressure. [1]
