Compound introduction
Organic metal compounds in production and life. For example, when the polymer compound is prepared, alkyl aluminum is used as a catalyst, in organic synthesis, the organometallic compound can provide a carbon negative ion, free radicals, and Carbin, so the organometallic compound is a class of extremely useful synthetic reagents. . In recent years, the research and application of the biological activity and pharmacological effects of organometallic compounds have become increasingly developed by the promotion and application of various organometallic compounds in bioactive studies. Therefore, it is necessary to master the basics of some organic metallic compounds.
The metal ions present in the biological body are often used with a large atom having a large electronegressive weight of nitrogen, oxygen, and binds to an organic molecule. These compounds are not organic metal compounds. However, the study of carbon-metal coordinates generated by transition metal and organic compounds makes the distance between the organometallic compound and the organometallic complexes are increasing. Metal ions in the enzyme molecule are extremely important to maintain biological macromolecular conformation and enzyme catalytic function. For example, zinc ions are part of the carbonated anhydrase, and the function of carrier oxygen in hemoglocritis is also accomplished by iron ions in hemoglin to oxygen reversible.
Compound Names
Organic metal compound naming, the most common is the name of the metal after the organic group.
, for example:
CH3LI: methylhydration; (CH 3 ) 2 Hg: dimethyl mercury; (ch 3 ch 3 Al: triethyl aluminum;
Sometimes the corresponding organometallic compound is considered as silane Or derivatives such as soldells are named.
, for example:
(CH 3 ) 4 Si: Tumenylsilane; (CH 3 CH 2 ) 3 SNCH 3 : ethylmethyltin;
as an organometallic compound molecule In addition to being connected to an organic group, a metal atom is connected to the organic group, it can be seen as an inorganic salt with an organic group to be named.
, for example:
CH 3 ch 2 mgl: iodide ethyl magnesium; CH 3 ZnCl: Chloride zinc chloride; (CH 3 ) 3 pbh: hydrogenated trimethyl lead.
Preparation
1, the active metal and the halogenated hydrocarbon reaction are prepared by the active metal and the halogenated hydrocarbon reaction, and the corresponding organometallic compound can be prepared. . For example,
2, a Grid reagent is prepared with anhydrous metal halide agent, which can be used to prepare an organometallic compound of an unactivated metal.
, for example:
3, the alkyl lithium is reacted with a metal halide reaction by alkyl lithium with a neutral metal halide, which can be used to prepare another organic metal Compound. For example:
General property
The properties of the organometallic compounds mainly depend on the chemical bond formed between the metal atom and the carbon atom. Due to the difference between the body, the nature of the chemical bond formed by the metal atom and the carbon atom is different. Therefore, the properties of organometallic compound cannot be generalized. The properties of the organic metal compound have the following three cases:
ion compound properties
containing the organometallic compound of the living metal, due to the polarity of the carbon-metal key, such The metal compound has the properties of the ionic compound.
For example: methyl potassium (CH 3 k), the C-K bond in the molecule mainly exhibits the characteristics of ionic bonds. The compound is a solid at room temperature, and has many properties formed by methyl negative ions and potassium ions, particularly with very lively free carbon negative ions. For example, it can be combustible in air, which is very easy to bind to moisture, and a severe reaction can occur with an acidic substance or oxidant.
Coalth of the nature of the compound
is formed of an organometallic compound formed by an inactive metal, since the carbon-metal bond has the nature of polar covalent bond, such metal organic compounds have a total The nature of the compound compound.
, for example: dimethyl mercury [(CH 3 ) 2 hg], the C-HG bond in the molecule mainly shows a common price nature. The compound is colorless liquid at room temperature, soluble in most organic solvents, no reaction with water, oxygen and most inorganic acid at room temperature, can be decomposed into mercury and methylstate, methyl, methylstate. Synthesis of ethane immediately. From the reaction of the heat dissolution into a free base, dimethyl mercury is an organic compound, and the C-HG key has a covalent bond.
Louis Acid
is formed from metal, aluminum, gallium, indium, and the organometallic compounds, carbon-metal bonds have the nature of polar covalent bonds. In the organometallic compound molecules formed by third host elements such as aluminum or gallium, the metal atom is not 8 electron saturated stabilizing structures, and has a tendency to form a dimer or accept electronic pair to achieve a saturated stable structure.
For example: trimethyl aluminum is often present in the form of dimer, and trimethyl gallium can form 1: 1 complex of Lewis (such as trimethylamine, diethyl ether, etc.). This means that the organometallic compound formed by the third host element is a Lewis acid with the Louisi electron with a lonely electron layer to saturate an electronic layer structure.
Common compounds
The organometallic compound has a wide variety, and widely used. With the development of the industry, scientific advancement, the research and use of organometallic compounds will be more in-depth, more extensive, and more commonly used organometallic compounds.
Butyllithium
Organic lithium compound is an important alkali metal organic compound, which is important in the preparation of organic synthesis and polymer compounds. Butyzithium is one of the applications.
Butyl lithium can be soluble in benzene or cyclohexane, and its properties are similar to the Ghr reagent, and the Big's reagent is lively. Some reactions that can have a very value of use.
1, with a hydrocarbon reaction
butyllithium reaction with a hydrocarbon containing a relatively activated hydrogen atom, a lithium atom replaces the active hydrogen atom, and has a new organic lithium compound and n-butane.
The above reaction can be seen as a process of removing a proton from a lithium salt having a strong alkali carbon negative ion from the substrate to obtain a new carbon negative ion. Such a reaction represents a method of preparing complex organic lithium compounds from a simple organic lithium compound, referred to as metalization of hydrocarbons.
2, reaction with carbon dioxide
butyllithium reacting with carbon dioxide, primarily lithium pentanoate, lithium palellium reaction with butyl lithium, and its formation hydrolysis finally obtained ketone.
3, the addition reaction of olefin
butyllithium and olefin reactive, carbon carbon double bond addition. If the non-symmetrical olefin is added, the lithium atom is added to a double bond carbon atom containing less hydrogen-containing. Such as:
4, a catalyst of a polymer compound
butyllithium and other organic lithium compounds can be used as a catalyst that is combined with a polymer compound by an olefin. For example, polyethylene is polymerized by ethylene, polymerized with isoprene polymerization into polyisoprene (synthetic natural rubber), and the like.
Dimethyl zinc
Organic zinc compound is R 2 zn, and there is a linear C-Zn-C skeleton in molecules.
Dimethyl zinc [(CH 3 ) 2 zn] normal temperature is a volatile liquid, boiling point 44 ° C, its chemical properties is not as good as The organic lithium compound is lively.
Dimethyl zinc is often used as a catalyst for polymerization, such as initiating agents when various olefin monomers and carbonylation polymerization, is also a composition ingredient of Ziegle Yatta composite catalyst. In the case of organic zinc as an initiator, the polymerization speed and the molecular weight of the polymer vary depending on the composition of the composite catalyst.
Triethyl aluminum
There are many types of organoaluminum compounds, and can be divided into three categories:
r in accordance with the number of hydrocarbon groups in aluminum atoms. SUB> 3A1, R 2 ; raiz 2 ;
where R represents the hydrocarbyl group, Z represents H, F, CL, Br, I, OR, SR, NH 2 , nhr, pr 2 , etc.
Triethyl aluminum is a colorless liquid, and it can be quickly oxidized to air in contact with air. When the water is strong, the water is strongly reacted, and aluminum hydroxide and ethane are generated, and a large amount of heat is produced. Triethyl aluminum is usually soluble in hydrocarbon solvents, which is particularly careful. Due to the physical properties of triethyl aluminum, poor thermal stability, it is difficult to obtain a pure product. A composite catalyst composed of triethyl aluminum and titanium tetrachloride is referred to as a Ziegler tower catalyst, which can make ethylene to polymerize at normal pressure, and propylene can also provide propylene polymerization. Therefore, triethyl aluminum is produced in a large number of industrial, widely used.