CN102993206B - Method for synthesising tetraphenylporphyrin metal complex via one-step process - Google Patents

Abstract

The invention discloses a method for synthesizing tetraphenylporphyrin metal complexes in one step, comprising the following steps: (1) dissolving metal acetate in DMF, metal acetate: DMF=1g:8~16ml; (2) Add solvent propionic acid to the reaction vessel, then add benzaldehyde, DMF solution dissolved in metal acetate and pyrrole solution diluted with propionic acid in sequence, and reflux at 120-150°C for 30-120min ; Wherein the mol ratio of benzaldehyde, pyrrole and metal acetate is 1:1:0.25～2.5, the volume ratio of solvent propionic acid and DMF is 1:1～1:1.5; (3) After the reaction finishes, cool, remove Solvent, separated to give the product. The process has the characteristics of low cost of raw materials, mild reaction conditions, simple operation, less pollution, and environmental friendliness. It changes the previous method of synthesizing metalloporphyrins in two steps, saves time, and can prepare more tetraphenylporphyrins. Porphyrin metal complexes, thus providing more possibilities for the application of various metal porphyrin dyes in dye-sensitized solar cells.

Description

A kind of method of synthesizing tetraphenylporphyrin metal complex by one-step method

technical field

The invention belongs to the field of synthetic chemistry, and in particular relates to a synthesis method of a tetraphenylporphyrin metal complex.

Background technique

Porphyrin is an important organic compound, which is used to synthesize various pesticides, medicines, advanced dyes and various functional materials. Porphyrins have a macrocyclic conjugated structure with both rigidity and flexibility, certain aromaticity, good stability, and wide spectral response, so they have a wide range of uses. Metalloporphyrin compounds play an important role in medicine, biology, catalysis, materials, etc., which have aroused widespread interest and have great application potential. Tetraphenylporphyrin metal complexes are intermediates of porphyrin-based solar cell sensitizers, which can be used to synthesize porphyrin-based dye sensitizers with more structures, thus providing more opportunities for their application in dye-sensitized solar cells. many possibilities.

The structure of the tetraphenylporphyrin metal complex is as follows:

Adler (J.Am.Chem.Soc., 1964,84(15):3145-3149) reported a synthetic method of tetraphenylporphyrin metal complexes, the first step using pyrrole and benzaldehyde in propionic acid Under the condition of solvent, the reaction first generates tetraphenylporphyrin, and in the second step, under the condition of chloroform as solvent, it reacts with metal salt to generate metal tetraphenylporphyrin. This method yield is very low, the first step has only about 15%, the second step is about 80%, and the total yield of the two-step reaction has only about 12%; and the method has complicated reaction process, long reaction time, and is difficult to operate.

Contents of the invention

The purpose of the present invention is to overcome above-mentioned deficiencies in the prior art, provide a kind of method for synthesizing tetraphenylporphyrin metal complex in one step, make the method for synthesizing metalloporphyrin in two steps become one-step synthesis, save time, improve Improved productivity and easier operation.

To achieve the above object, the present invention adopts the following technical solutions:

A method for synthesizing tetraphenylporphyrin metal complexes in one step, comprising the following steps:

(1) Dissolve metal acetate in DMF (N,N-dimethylformamide), metal acetate: DMF=1g: 8~16ml;

(2) First add solvent propionic acid into the reaction vessel, then add benzaldehyde, DMF solution dissolved in metal acetate and pyrrole solution diluted with propionic acid in sequence, and reflux at 120-150°C for 30- 120min; wherein the molar ratio of benzaldehyde, pyrrole and metal acetate is 1:1:0.25~2.5, and the volume ratio of solvent propionic acid to DMF is 1:1~1:1.5;

(3) After the reaction is completed, cool down, remove the solvent, and perform layer separation with a silica gel column to obtain the product.

The volume ratio of the propionic acid used to dilute the pyrrole to the pyrrole is: 3:1-10:1.

The metal acetate is zinc acetate, copper acetate or nickel acetate.

The step of removing the solvent in the step (3) is as follows: pour the cooled reaction liquid into water, after precipitation occurs, perform suction filtration, and take the filter residue.

The step of separating the middle plate in the step (3) is as follows: the substance after removing the solvent is vacuum-dried and then dissolved in chloroform, using silica gel as the stationary phase and chloroform as the eluent to carry out dry-passing through the column, and collecting the second layer of purple-red strip, concentrated and dried to obtain a purple solid powder as the product.

The following step is also included before the step (2) reaction: reflux pyrrole at 115° C. to obtain a colorless solution, and store it away from light.

The specific steps of the step (2) are as follows: add solvent propionic acid into the reaction vessel, then add benzaldehyde, stir, and reflux at 120-150°C. After the temperature is stable, use a constant pressure dropping funnel to drop the dissolved DMF solution of metal acetate, then slowly add pyrrole-dissolved propionic acid solution with a rubber dropper, after all the reactants are added, react for 30-120min.

The reflux temperature is 140°C.

The reaction time is 90min.

Reaction formula of the present invention is:

Wherein M can be metal elements such as zinc, copper, nickel, etc.

In the present invention, (1) since metal acetate is insoluble in the original solvent propionic acid, the metal salt is dissolved in a DMF solution with a boiling point close to that of propionic acid. (2) Since when the DMF solution dissolved with metal salt is added to propionic acid, the metal salt will precipitate after adding a certain amount. After the experiment, it is found that the ratio of propionic acid to DMF is about 1:1~1:1.5. (3) During the reaction process, the order of adding various reactants is benzaldehyde, DMF solution dissolved in metal salt, and pyrrole solution diluted with propionic acid. This order of addition can effectively prevent pyrrole and benzaldehyde from synthesizing other form of polymers, reducing the yield loss of the target product. (4) Since the black solid needs more solvents to dissolve in chloroform, it is not suitable for wet column loading, so the present invention uses dry column loading, which can more effectively reduce the loss of products.

In the preparation process of the present invention, the metal salt is dissolved in DMF and then directly added to the reaction system, and the tetraphenylporphyrin metal complex is directly obtained through one-step reaction. The process has (1) the use of cheap and easy-to-obtain raw materials, which can reduce costs, and the raw materials are less toxic and less harmful to the human body; (2) the reaction conditions are mild, the operation is simple, and time is saved; (3) the production pollution is small and friendly to the environment. The present invention changes the previous two-step method for synthesizing metalloporphyrins, saves time, and can prepare more tetraphenylporphyrin metal complexes, so that various metalloporphyrin dyes can be applied to dye-sensitized solar cells Provides more possibilities.

Description of drawings

Fig. 1 is the nuclear magnetic resonance figure of the synthetic zinc tetraphenylporphyrin in embodiment 1.

Fig. 2 is the partial spectrogram of the zinc tetraphenylporphyrin synthesized in embodiment 1.

Detailed ways

The present invention will be further elaborated below through specific examples. It should be noted that the following descriptions are only for explaining the present invention, and do not limit its content.

Example 1:

Step 1: Since pyrrole is easily oxidized when placed in the air for a long time, first reflux pyrrole at 115°C to obtain a colorless solution and store it in the dark. Measure 0.68ml of pyrrole and pour it into 3.5ml of propionic acid. Shake well and ready to use.

Step 2: Weigh 2.9g of zinc acetate, dissolve it in 35ml of DMF solution, stir to dissolve it completely, and pour it into a constant pressure dropping funnel for use.

Step 3: Add 35ml of propionic acid and 1ml of benzaldehyde into a 100ml three-necked flask, stir, and reflux at 140°C. After the temperature is stable, drop in 2.9g of zinc acetate dissolved in 35ml of DMF solution, then slowly add propionic acid solution dissolved in 0.65ml of pyrrole with a rubber dropper, and react for 90min after all the reactants have been added.

Step 4: After the reaction, cool down, pour the product into about 500ml of water, a large amount of black solid appears, filter with suction, and dry the filter residue in vacuum.

Step 5: Dissolve the product in chloroform, then add silica gel, pass through the column by dry method, use silica gel as the stationary phase, and chloroform as the eluent, collect the second layer of purple-red band, concentrate, and dry to obtain 0.36g of purple solid powder , yield 25%.

Example 2:

Same as Example 1, but the zinc acetate in the second step changes copper acetate into, and the volume ratio of propionic acid and the DMF solution that is dissolved with copper acetate is 1:1.2, and every gram of copper acetate is dissolved in 15mlDMF solution, and reaction obtains Purple solid powder 0.22g, yield 15%.

Example 3:

Same as Example 1, but the zinc acetate in the second step changes nickel acetate into, and the volume ratio of propionic acid and the solution of the DMF that is dissolved with nickel acetate is 1:1.5, every gram of nickel acetate is dissolved in 16mlDMF solution, reaction Obtained 0.18 g of purple solid powder with a yield of 12%.

Note: The solubility of copper acetate and nickel acetate in DMF is not very high, and the metal salt should be ground into powder to facilitate dissolution.

Claims (4)

1. a method for synthesizing tetraphenylporphyrin metal complexes in one step, is characterized in that, comprises the following steps: (1) Metal acetate is dissolved in DMF, metal acetate: DMF=1g: 8～16ml; (2) First, add solvent propionic acid to the reaction vessel, then add benzaldehyde, DMF solution dissolved in metal acetate and pyrrole solution diluted with propionic acid in sequence, and reflux within 120-150°C for 30- 120min; wherein the molar ratio of benzaldehyde, pyrrole and metal acetate is 1:1:0.25～2.5, and the volume ratio of solvent propionic acid to DMF is 1:1～1:1.5; (3) after the reaction finishes, cool down, remove solvent, carry out chromatographic separation with silica gel column, obtain product; The step of chromatographic separation in the step (3) is: the substance after removing the solvent is dissolved in chloroform after vacuum drying, adopts silica gel as the stationary phase and chloroform as the eluent to carry out dry-passing through the column, and collects the second layer of purple Red band, concentrated and dried to obtain a purple solid powder as the product; The following steps are also included before the reaction in step (2): distilling pyrrole at 115° C. to obtain a colorless solution, which is stored away from light; The volume ratio of the propionic acid used to dilute the pyrrole to the pyrrole is: 3:1˜10:1. 2. method according to claim 1, is characterized in that, described metal acetate is zinc acetate, copper acetate, nickel acetate. 3. The method according to claim 1, characterized in that, the step of removing the solvent in the step (3) is as follows: pour the cooled reaction solution into water, carry out suction filtration after precipitation, and get the filter residue. 4. The method according to claim 1, characterized in that, the specific steps of the step (2) are: add solvent propionic acid in the reaction vessel, then add benzaldehyde, stir, and reflux at 120-150°C, After the temperature is stable, use a constant pressure dropping funnel to drop the DMF solution dissolved in metal acetate, and then slowly add the propionic acid solution dissolved in pyrrole with a rubber dropper. After all the reactants are added, react for 30-120 minutes .