Polydentate Phosphine Ligands
A polydentate phosphine ligand refers to a ligand having a plurality of coordinating atoms in a ligand, and these coordinating atoms are P atoms. Among the polydentate phosphine ligands, P acts as a coordination center atom and has an outer electron configuration of 3S23P3, which is a good electron donor (Lewis base), and at the same time, the low energy 3d empty orbit has the ability to accept electrons. In the position reaction, the feedback π bond is easily formed, so the organophosphine ligand is commonly used to stabilize the low-cost transition metal ion. Due to the early appearance and rapid development, multidentate phosphorus ligands have so far had many different types of structures. At the same time, since the polydentate phosphine ligand has good stability to metal ions, the formed complex also has a rich structure. Therefore, multidentate phosphorus ligands have been widely used in many fields.
Polydentate phosphine ligands and their complexes are diverse and diverse, and have a wide range of applications in the fields of organic synthesis, pharmaceutical industry, and optical research.
- Organic chemistry: The polydentate phosphine ligand has good stereo and electronic effects and can form multidentate phosphine complexes with various metal atoms such as ruthenium, rhodium, platinum, palladium, cobalt, iron, and the like. These polydentate phosphine complexes have good catalytic activity and can be used as catalysts. The formation of a catalytically active center on the surface of the polydentate phosphine complex facilitates sufficient contact of the catalyst with the substrate. At the same time, due to the special solubility of the catalyst, separation from the product can be achieved and it is easy to recycle. Therefore, polydentate phosphine ligands are widely used in the catalytic reactions of organic chemistry. The catalytic reaction mainly includes hydrogenation reaction, N-methylation reaction, formylation reaction, coupling reaction, allylation reaction, ethylene oligomerization reaction, Michael addition, hydrosilylation reaction and the like.
- Pharmaceutical industry: Metal complexes of polydentate phosphine ligands can be used in the preparation of radiopharmaceuticals. The complexes formed by the rhodium and the polydentate phosphine ligand have good coordination properties under the conditions of redox and acid-base, and do not change. Therefore, the complex is used as a carrier for the preparation of radiopharmaceuticals. In addition, the complex formed by the ruthenium and the polydentate phosphine ligand has an inhibitory effect on the growth of cancer cell tissues, but has no activity on normal non-cancer cells, so the polydentate phosphine ligand can also be used as an anticancer drug.
- Optical material: The complexes of polydentate phosphine ligands with metals such as Rh(I), Pt(II), Pd(II), Ag(I), Cu(I), Au(I), etc., all exhibit good luminescence properties, so It can be applied to the synthesis of optical materials. Especially the complexes of polydentate phosphine ligands with low-cost metals Cu(I), Ag(I), Au(I) play an important role in the preparation of fluorescent materials.
Polydentate phosphine ligands can be classified into chiral polydentate phosphine ligand and achiral polydentate phosphine ligand depending on whether they contain a chiral center. The polydentate phosphine ligand can be classified into an O-P ligand, a C-P ligand, an N-P ligand, etc., depending on the atom directly connected to the phosphorus atom.
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- Smith, Michele L. (2001), “ Syntheses and characterization of new potentially trans-chelating polydentate Phosphineligands: Complexes with platinum(II), palladium (II) and silver(I).” Abstracts of Papers, 221st ACS National Meeting 46(43), INOR-117.