The importance of coordination chemistry

The importance of coordination chemistry
The application of coordination compounds is very popular, it has penetrated into every field of natural science, no matter in practice and theory of sense is very important. This section only chooses some aspects introduced briefly.
In the application of inorganic chemistry
Hydrometallurgy
Can use chelating agent directly from the ore solution ontheleaching, reoccupy metal out appropriate reductant reductive into metal. For example, back in the early '40 s some countries have developed NiS etc ore in pressure under much ammonia solution, and then in the pressurized ontheleaching by hydrogen reduction to nickel powder.
NiS+6NH3 (aq)[pressure]Ni (NH3)62++S2-
Ni (NH3)62++H2 [pressure] Ni (powder) +2NH4++4NH3 Other such as Au has many is using CN extraction with (CN) into Au 2-again with Zn reductive into elemental gold.
4Au+8CN+2H2O→4Au(CN)2+4OH-
Zn+2Au(CN)2→2Au+Zn(CN)42-
Separation and purification
Due to the needs of the material preparation high purity, for those of a similar nature rare metal, often using formation complexes to expand
some qualitative difference, so as to achieve the purpose of separation, purification. For example Zr4 + and Hf4 + ion radius almost equally, nature is very similar. But in 0.125 mol/dm3HF K2ZrF6 and K2HfF6 in the solubility were 1.86 and 3.74 g (20100 gH2O), the latter to the former about twice, once to use this kind of difference with grading crystallization take elemental zirconium legal system. And as three price rare earth elements ions, slightly different radius (an average of about 1 PM), separate extremely difficult. In recent years, use them and oxygen and its content and its ability of different, so it can be extraction separation of rare earth elements to separation. Lighter larger rare earth metal ions, such as La3 + Ce3 +, Pr3 +, Nd3 +, etc, can be ErBenJi-18-with crown-6 (C20H24O6 "crown ether) generation is soluble in organic solvent Ln(NO3) of 3 C20H24O6 type with its content: And in its content La3 + around six five yuan ring, and oxygen atoms form octahedron coordination. Such a large octahedron hole (crown ether cavity radius for 320-360 PM) can only and radius of the larger light of rare earth such as: La3 +, Ce3 +, Pr3 +, Nd3 + generation such as stable complexes, and smaller, and radius heavy rare earth ions can't form a stable complexes. Such light re can be extraction to organic phase (if use crown ether adsorption column, it made light of rare earth in adsorption column), heavy rare earth to remain in the water, so as to achieve the purpose of separation.
The design has special functions synthesis molecules
Professor Underhill, a research team led the design of "molecular metal", every molecule of all metal atoms in a certain direction, it ranks together electronic can along the metal atoms flow chain. How to make these metal atoms are combined and properly stack up, has now found sulfur and selenium is to connect metal ideal choice. As shown in figure 19-10 shows: this show that every molecule is flat type, and there is a a platinum of atoms around it, there are four sulfur atoms. Each of the platinum atoms above and below each have a belong to a layer or the next layer of molecules platinum atoms. So, there are a lot of available for electronic article through "platinum-sulfur atoms chain" throughout the crystal. These molecules of conductive metal performance depends not only on the merits of the metal atoms, the distance between still depends on the different way between the molecules in the stack adjacent sulfur atoms toward each other levels. Obviously, this requires chemist wants elaborate design, adjust the structure of molecules, make electronic can depend on the designer's intent in the crystal, the flow. This kind of "molecular metal" will be the future "molecular computer" has very big effect. Similar complexes and metallic porphyrin complexes LB film, made light store materials, cancer drugs, etc.
Figure 19-11 Underhill professor and design of a "molecular metal", with
X-ray method to determine the structure.
The molecules have the plane of layered stack, so that electronic can horizontally in between the molecules through.。