CN102382141A - Preparation methods of sulfur atom bridging coordination compound with bimetal unit - Google Patents

Abstract

The preparation method of the sulfur atom bridged double metal unit complex, one of the methods is under the condition of anhydrous and oxygen free, the tetrahydrofuran solution of the double metal building unit M ₂ (DAniF) ₃ (OOCCH ₃ ) and the aqueous solution of HS ^- ion salt reaction to synthesize a complex sensitive to moisture and air, and then place the obtained complex in the air for deprotonation coupling oxidation reaction to prepare the product. The second method is to prepare the product by reacting the tetrahydrofuran solution of the bimetallic building unit M ₂ (DAniF) ₃ (OOCCH ₃ ) with the aqueous solution of the S ^2- ion salt in air. The invention prepares the sulfur atom bridged double metal unit complex which is insensitive to moisture and air and can stably exist in the air. Its properties can be characterized in the air, and the research results on the structure, optical and electrical properties of the product show that the prepared sulfur atom bridged double molybdenum unit complex has strong electron coupling and electron transfer capabilities in the molecule, and is suitable for Model compounds for studying molecular electronic devices.

Description

Preparation method of sulfur atom bridged double metal unit complex

technical field

The invention relates to a preparation method of a coordination compound, in particular to a preparation method of a sulfur atom bridged double metal unit complex.

Background technique

With the rapid development of information science and related technologies, higher requirements are put forward for computer micro-processing systems. The key to designing and developing a new generation of ultra-miniature, ultra-high-speed, and ultra-large-capacity computers lies in the development of new high-density integrated circuits. The traditional microelectronics industry uses photolithography technology to manufacture large-scale integrated circuits on single crystal silicon wafers, and the processing technology is approaching the limit. As early as 1974, Aviram et al. proposed that certain molecules could replace silicon chips, but it was not until recent years that progress in this field has been made. Molecular electronic materials can quickly process a large amount of information at the molecular scale, and their high density, high response rate and high energy conversion efficiency have attracted the attention of many researchers. Scientists believe that the computer of the future should be a molecular computer, that is, to detect, process, transmit and store information through chemical and physical actions at the molecular level. Therefore, the research on "molecular electronic devices" has become an international frontier topic and hot field intersecting with chemistry and material science, and molecular wires and molecular switches are the focus of it. In recent years, some systems that are expected to be used in practice have been proposed, such as photo-controlled molecular wires composed of bipolypyridine complexes connected by conjugated polyacetylene chains, and redox-type electronic control wires composed of anthraquinone lariat ether combined with cations. Molecular switches and nucleic acid-type molecular wires composed of DNA molecules, etc. However, since the study of molecular wires and molecular switches involves long-range light and electron transfer reactions, many influencing factors have not been fully understood, which restricts the development of this field. However, some bridged bimetallic unit complexes can undergo intramolecular electron transfer reactions, causing the intervalence charge transfer process (IVTC) and accompanied by changes in the length of the metal-metal covalent bond, which can be more conveniently controlled and detected, and has the potential to become a molecule The potential of the device has aroused the interest of many researchers. Moreover, due to its diversity, relative stability, and unique electrical and optical properties, it has become one of the ideal models for studying molecular electronic devices such as molecular wires, molecular switches, and molecular rectifiers.

Investigation of intramolecular electronic coupling and electron transport in bridged bimetallic unit complexes, with well-defined electronic structures of metal-metal bonded monomers compared to mononuclear metal ions. For example, Mo ₂ formed by quadruple bonds has an electronic configuration of σ ² π ⁴ δ ² , its HOMO(δ) is different from HOMO-1(π) in symmetry, and the energy level difference is large. The redox reaction of the metal center and the metal -Electronic coupling between metals is only related to two δ valence electrons, which brings great convenience to the analysis of electronic structure and orbital interaction. Secondly, the molecular structure, electronic configuration and spectral properties of covalent bimetallic monomers are interrelated, and the change of electronic configuration is the change of the metal-metal bond level, which is manifested in measurable parameters such as metal-metal bond length and changes in the δ→δ* transition in the visible region. Using metal-metal bonds and δ→δ* absorption spectra as probes of electronic structure, combined with simple methods such as electrochemical and magnetic properties to explore the electronic coupling properties of complexes, the research methods are simple and easy to implement.

At present, most of the related bridged bimetallic unit complexes are bimetallic unit complexes bridged by organic ligands. Because these compounds are sensitive to air and moisture, the research on their physical and chemical properties has caused certain limitations. Moreover, when synthesizing the bimetallic unit complexes bridged by organic ligands, it is first necessary to design and synthesize a suitable organic bridging ligand, and then react with the bimetallic building blocks, and the synthesis steps are cumbersome. Since this type of compound is sensitive to air and moisture, there are problems such as harsh synthesis conditions, troublesome post-processing, low yield, and complicated single crystal cultivation system.

Contents of the invention

The object of the present invention is to provide a method for preparing a sulfur atom-bridged bimetallic unit complex that exists stably in the air and can be applied in actual research and production.

In order to achieve the above object, the present invention adopts following two technical schemes:

The _first technical solution is to synthesize a ^moisture- _and air _- sensitive complex, and then the resulting complex is placed in the air for deprotonation coupling oxidation reaction to prepare a sulfur atom bridged double metal unit complex;

The molar ratio of the bimetallic building block M ₂ (DAniF) ₃ (OOCCH ₃ ) to HS ^- ions is 1:5;

M in the bimetallic building block M ₂ (DAniF) ₃ (OOCCH ₃ ) represents Mo or W, and DAniF represents N,N'-di-p-methoxybenzamidine or N,N'-di-p-methyl Derivatives of oxybenzamidine.

The second technical solution is to prepare a sulfur atom-bridged double metal unit complex by reacting the tetrahydrofuran solution of the double metal building unit M ₂ (DAniF) ₃ (OOCCH ₃ ) with the aqueous solution of the S ^2- ion salt in the air ;

The molar ratio of the bimetallic building block M2(DAniF)3(OOCCH3) to S2- ions is 1:5;

M in the bimetallic building block M2(DAniF)3(OOCCH3) represents Mo or W, and DAniF represents N, N'-two-p-methoxybenzamidine or N,N'-two-p-methoxy Derivatives of benzamidine.

The sulfur atom bridged double metal unit complex prepared by the method of the invention has stable existence in air and excellent physical and chemical properties, such as optical and electrical properties, special magnetic properties and the like.

The method of the invention is easy to operate and control, and the method is simple and easy to study the properties of the prepared product.

To characterize the composition, structure and properties of the product obtained by the method of the present invention, elemental analysis, nuclear magnetic ( ¹ H NMR), X-ray single crystal structure diffraction, ultraviolet-visible spectroscopy, cyclic voltammetry electrochemistry, magnetic susceptibility testing, etc. can be selected respectively. The elemental analysis results show the composition and content of each element in the product, 1H NMR nuclear magnetic resonance and X-ray single crystal structure diffraction show the structural characteristics of the compound, ultraviolet-visible spectroscopy and cyclic voltammetry electrochemical properties respectively characterize the optical and electrical properties of the product, and the magnetic susceptibility test The results indicated the special magnetic properties of the product.

Method of the present invention also has the following advantages:

1. The sulfur atom-bridged bimetallic unit complex synthesized by the present invention is not sensitive to moisture and air, can exist stably in the air, and is convenient for its property research.

2. The preparation method adopted is simple, easy to operate and easy to control, the post-treatment process is simple, the yield is high, and it is easy to realize industrialization.

3. The tests of optical and electrical properties show that the synthesized sulfur atom-bridged bimetallic unit complex has strong electron coupling and electron transfer capabilities, providing an ideal model for the research of molecular electronic devices such as molecular wires and molecular switches. compound.

Description of drawings

Fig. 1 is an X-ray single crystal diffraction crystal structure diagram of the complex [Mo ₂ (DAniF) ₃ ] ₂ (SH) ₂ synthesized in Example 1.

Fig. 2 is the X-ray single crystal diffraction crystal structure diagram of the product prepared in Examples 1 and 2-sulfur atom-bridged bimetallic unit complex [Mo ₂ (DAniF) ₃ ] ₂ S ₂ .

Fig. 3 is the ultraviolet-visible electron spectrogram of the product obtained in embodiment 2.

Fig. 4 is the cyclic voltammetry electrochemical property test graph of the product obtained in Example 2.

Detailed ways

The present invention will be further described below in conjunction with embodiment.

Example 1:

The first step is the configuration of 10mL NaHS aqueous solution with a concentration of 0.2mol/L. Add 0.48 g (2 mmol) Na ₂ S·9H ₂ O to the Schlenk bottle, dissolve it in 10 mL distilled water, measure 0.2 mL of 10 mol/L hydrochloric acid solution and add it to the Na ₂ S aqueous solution to obtain a yellow and clear NaHS aqueous solution. Nitrogen deoxygenation for 3 hours, stand-by.

In the second step, under anhydrous and oxygen-free conditions, 0.2044g (0.2mmol) Mo ₂ (DAniF) ₃ (OOCCH ₃ ) was dissolved in 10mL tetrahydrofuran, all the solids were dissolved, and a bright yellow clear solution was obtained. Under stirring, slowly dropwise add 5 mL of the NaHS aqueous solution prepared in the first step. During the feeding process, the solution gradually becomes turbid and the color deepens. After feeding for 15 minutes, a large amount of yellow precipitates were formed, and the color of the solution was brown. After reacting for 4 hours at room temperature, there was no other significant change. Filter, wash the product with ethanol 3 times, 15 mL each time, remove impurities, and vacuum dry to obtain a yellow solid. Add 10 mL of dichloromethane, all the solids are dissolved, and filter into the reaction tube, the filtrate is yellow-brown. Slowly add 30 mL of ethanol along the wall of the reaction tube. The single crystal was cultivated by the solvent diffusion method, and after one week, blocky yellow crystal-complex [Mo ₂ (DAniF) ₃ ] ₂ (SH) ₂ was obtained. It was characterized by X-ray single crystal structure, and its crystal structure diagram is shown in Figure 1. For clarity of the structure diagram, all p-methoxybenzene connected to N is omitted.

In the third step, the yellow crystal obtained under anhydrous and oxygen-free conditions in the second step is exposed to the air for 48 hours, and a deprotonation coupling oxidation process occurs to obtain the desired columnar black crystal product-complex [Mo ₂ (DAniF ) ₃ ] ₂ S ₂ . It was characterized by X-ray single crystal structure. Its crystal structure is shown in Figure 2. For clarity of the structure, all p-methoxybenzenes connected to N are omitted.

Example 2:

Weigh 0.409g (0.4mmol) Mo ₂ (DAniF) ₃ (OOCCH ₃ ) into a 100mL Sehlenck bottle, add 10mL tetrahydrofuran, all the solids are dissolved to obtain a bright yellow clear solution. Under stirring, add 5 mL of 0.4 mol/L Na ₂ S aqueous solution, and a large amount of yellow precipitates are formed immediately. At this time, open the Schlenk bottle in the air, and react at room temperature for 24 hours, and the color of the solid changes slowly: yellow-yellow-brown-brown , and finally a large amount of brown-black solid was obtained. Filter, wash the product with a mixture of distilled water and ethanol (the volume ratio of distilled water and ethanol is 2:1) to remove impurities until the pH=7, and vacuum dry to obtain a brown-black powder. Add 10mL of dichloromethane, all the solids are dissolved, filter into the reaction tube, the filtrate is brown-black. Slowly add 30 mL of ethanol along the wall of the reaction tube. The crystal was cultivated by the solvent diffusion method, and after one week, a columnar black crystal product was obtained, and the X-ray single crystal structure characterization result was the same as the crystal structure obtained in Example 1, as shown in FIG. 2 . Figure 3 is the UV-visible electronic spectrum of the product. The characterization results show that there is a strong absorption peak at 803nm, indicating that the electronic coupling and electron transfer capabilities between the bimetallic units in the complex are strong, and the energy required for electronic transitions is very small. Low. Figure 4 is the test result of the cyclic voltammetry electrochemical properties of the product, the results show that the complex has two reversible one-electron redox processes, the first redox process E1/2(1)=-1.345V, the second E1/2(2)=0.365V in a redox process, and the difference between the two is ΔE1/2=1.71V, which also shows that the electronic coupling and electron transfer capabilities between the double molybdenum units in the complex are strong, and it is suitable for the study of molecular Model compounds for electronic devices.

Claims (9)

1. A preparation method of a sulfur atom-bridged double metal unit complex, characterized in that: under anhydrous and oxygen-free conditions, a tetrahydrofuran solution of a double metal building unit M ₂ (DAniF) ₃ (OOCCH ₃ ) and ^HS- The aqueous solution of ionic salt reacts to synthesize complexes sensitive to moisture and air, and then puts the obtained complexes in the air for deprotonation coupling oxidation reaction to prepare sulfur atom-bridged bimetallic unit complexes; The molar ratio of the bimetallic building block M ₂ (DAniF) ₃ (OOCCH ₃ ) to HS ^- ions is 1:5; M in the bimetallic building block M ₂ (DAniF) ₃ (OOCCH ₃ ) represents Mo or W, and DAniF represents N,N'-di-p-methoxybenzamidine or N,N'-di-p-methyl Derivatives of oxybenzamidine. 2. A preparation method of a sulfur atom bridged double metal unit complex, characterized in that: in the air, by the tetrahydrofuran solution of the double metal building unit M ₂ (DAniF) ₃ (OOCCH ₃ ) and S ^2- ion salt React in aqueous solution to prepare sulfur atom bridged bimetallic unit complexes; The molar ratio of the bimetallic building block M ₂ (DAniF) ₃ (OOCCH ₃ ) to S ^2- ions is 1:5; M in the bimetallic building block M ₂ (DAniF) ₃ (OOCCH ₃ ) represents Mo or W, and DAniF represents N,N'-di-p-methoxybenzamidine or N,N'-di-p-methyl Derivatives of oxybenzamidine. 3. the preparation method of sulfur atom bridging double metal unit complex as claimed in claim 1, is characterized in that: the aqueous solution of described HS ^- ion salt is prepared by the sodium salt of HS ^- ion or other water-soluble salt, prepares During the process, nitrogen was passed through to remove oxygen for 3 hours, and the final concentration was 0.2 mol/L. 4. the preparation method of sulfur atom bridging double metal unit complex as claimed in claim 2, is characterized in that: described S ^2- The aqueous solution of ion salt is prepared by the sodium salt of S ^2- ion or other water-soluble salts , the concentration is 0.4mol/L. 5. the preparation method of sulfur atom bridging double metal unit complex as claimed in claim 1 or 2 is characterized in that: the tetrahydrofuran solution of described double metal construction unit M ₂ (DAniF) ₃ (OOCCH ₃ ) is prepared by bis The metal building unit M ₂ (DAniF) ₃ (OOCCH ₃ ) is prepared by dissolving in tetrahydrofuran under anhydrous and oxygen-free conditions. 6. the preparation method of sulfur atom bridging double metal unit complex as claimed in claim 1, is characterized in that: the concrete operation step that described synthesis goes out the complex sensitive to moisture and air is, M ₂ (DAniF ) ₃ (OOCCH ₃ ) tetrahydrofuran solution and HS ^- ion salt aqueous solution according to the molar ratio of M ₂ (DAniF) ₃ (OOCCH ₃ ) and HS ^- ion as 1:5 ingredients, under anhydrous and oxygen-free conditions, while stirring Slowly add the aqueous solution of HS ^- ion salt to the tetrahydrofuran solution of M ₂ (DAniF) ₃ (OOCCH ₃ ), stir and react at room temperature for 3 to 5 hours, until there is no obvious change in the reaction, filter out the precipitate, the precipitate Wash 3 times with ethanol to remove impurities, and dry under reduced pressure to obtain a yellow solid, then dissolve all the yellow solid in methylene chloride solution, filter the solution into the reaction tube, then slowly add ethanol along the wall of the reaction tube, and use The single crystal is cultivated by the solvent diffusion method to obtain a yellow crystal, which is a complex sensitive to moisture and air, and the volume ratio of the above-mentioned ethanol and dichloromethane is 3:1. 7. The preparation method of the sulfur atom bridged double metal unit complex as claimed in claim 2, characterized in that: the specific operation steps for preparing the sulfur atom bridged double metal unit complex are: M ₂ ( DAniF) ₃ (OOCCH ³ ) tetrahydrofuran solution and S ^2- ion salt aqueous solution are mixed according to the molar ratio of M ₂ (DAniF) ₃ (OOCCH ₃ ) to S ^2- ion as 1:5, in the air, while stirring Slowly add the aqueous solution of S ^2- ion salt dropwise to the tetrahydrofuran solution of M ₂ (DAniF) ₃ (OOCCH ₃ ), stir and react at room temperature for 24 hours until there is no obvious change in the reaction, filter out the precipitate, and wash the precipitate with distilled water and ethanol mixed solution to remove impurities until the pH = 7, vacuum-dried to obtain a brown-black solid, and then all the brown-black solid was dissolved in dichloromethane solution, the solution was filtered into the reaction tube, and then along the Slowly add ethanol to the wall of the reaction tube, cultivate the single crystal by the solvent diffusion method, and obtain black crystals, which are sulfur atom-bridged bimetallic unit complexes, and the volume ratio of the above-mentioned ethanol and dichloromethane is 3:1. 8. the preparation method of sulfur atom bridging double metal unit complex as claimed in claim 1 or 6, it is characterized in that: described anhydrous anaerobic condition comprises adopting Schlenk vacuum line operation technique, and used solvent is A solvent free of moisture and oxygen. 9. The preparation method of the sulfur atom-bridged bimetal unit complex according to claim 6 or 7, characterized in that: the stirring is magnetic stirring.

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