1 The history
Metal organic chemistry is the study of chemical organic compounds containing carbon-metal bonds. The rapid development of metal organic chemistry was in 1951. Thanks to the work of Wilkinson, Woodward, and Fischer, the famous sandwich compound-ferrocene was synthesized. In 1954, Wilkinson and Birmingham succeeded in synthesizing the first rare earth triiron compound, which marked the birth of rare earth organic chemistry. In 1963, the synthesis of Cp2SeCl was first reported. 10 years later, the crystal structure of Cp2SeCl was discovered. In 1991, Sakakura discovered that [Cp.NdH]2 and Cp.NdH(SiMe)2 can catalyze the hydrosilylation reaction of olefins and the dehydrogenative coupling of silanes. One year later, the first rare earth bis(pentamethyl)cyclopentadienylsilyl compound was synthesized. With the improvement of synthesis technology, various advanced testing methods have been continuously introduced, especially the adoption of X-ray diffraction technology, high-resolution mass spectrometry, nuclear magnetic resonance, which has led to the rapid development of rare earth metal organic chemistry.
2 Introduction of metal organic compounds
The application of metal organic compounds is very extensive. Organic sodium(Wurtz reaction, Wurtz-Fittig reaction), organic magnesium(Grig-nard reaction), organic lithium and organic aluminum are the most common and most widely used metal organic compounds. Metal organics are widely used as commercial catalysts for both homogeneous and stoichiometric reagents. The field of metal organics combines traditional inorganic chemistry and organic chemistry.
3 The applications of main metal organic compounds
3.1 Organic Copper compounds
Organic copper compounds are compounds contain carbon-copper bonds in organometallic chemistry. Copper is one of the oldest transition metals to be used in synthetic organic chemistry and organocopper reagents has become one of the most popular synthetic tools in the synthesis of natural product. The unique properties of organocopper compounds make them unavoidable reagents for the conjugate addition and other important reactions.
3.2 Organic Germanium compounds
Organic germanium compounds are organometallic compounds containing carbon-germanium chemical bonds. Germanium shares the group 14 with silicon, tin and lead in the periodic table. One reason for the limited synthetic value of organic synthetic germanium compounds is the cost of germanium compounds. However, germanium is considered as a non-toxic alternative of many toxic organotin reagents. Compounds such as tetramethylgermanium and tetraethylgermanium are used as precursors for germanium dioxide chemical vapor deposition in the microelectronics industry.
3.3 Organic Tin compounds
Organic tin compounds or stannanes are compounds based on tin with hydrocarbon substituents. The first organic tin compound was diethyltin diiodide discovered by Edward Frankland. The field grew rapidly in the 20th century, especially after the Grignard reagents were found that can be used to produce Sn-C bonds. The field has a wealth of applications in the continuing activities of industrial and research laboratories.
3.4 Organic Zinc compounds
Organic zinc compounds contain carbon-zinc chemical bonds in organic chemistry. They are among the first organometallic compounds. Most organic zinc compounds are easily oxidized and decomposed when dissolved in protic solvents. All reactions using organozinc reagents need to be reacted in the absence of inert gas, such as nitrogen or argon. Organic zinc compound is an excellent reagent for transition metal-mediated processes.
3.5 Organic Lead compounds
Organolead compounds are compounds with carbon-lead bonds in their molecules. The first synthetic organic lead compound is hexaethyl diphosphate, synthesized in 1858. In organic chemistry, the dominance of Pb(IV) in organolead chemistry is remarkable, which is quite special because divalent lead is more often found in inorganic lead compounds. The reason for this is that the electronegativity of lead in inorganic lead compounds is lower than that of nitrogen, oxygen, and halogen, and the partial positive charges on the lead atoms leads to a stronger contraction of the 6s orbital than the 6p orbital, which is known as inert pair effect. Organolead triacetates have been developed as inexpensive and versatile reagents for electrophilic arylation, alkynylation and vinylation of carbon nucleophiles.
This article mainly summarizes the applications of the main metal organic compounds. Each metal organic compound has its own characteristics. In the organic chemistry, the unique characteristic of each metal organic compound should be taken into account during synthesis process. To be in line with the principles of green chemistry, higher requirements are placed on the research and development of organic metals.