CN115636780A - A kind of organic photosensitizer and preparation method thereof - Google Patents

Abstract

The invention discloses an organic photosensitizer and a preparation method thereof. The organic photosensitizer has good water solubility and good light stability, has strong absorption in visible light, can efficiently generate singlet oxygen, has the maximum singlet oxygen quantum yield of 0.65, can catalyze the selective oxidation of the methyl phenyl sulfide into nontoxic methyl phenyl sulfoxide, and has wide application prospect in the field of green organic synthesis; the organic photosensitizer can be simply and efficiently synthesized through Suzuki coupling reaction and Zincke reaction, and the synthesis method is simple, high in yield, short in production period and suitable for large-scale industrial production.

Description

A kind of organic photosensitizer and preparation method thereof

technical field

The invention relates to the field of synthesis and preparation of photosensitizers, in particular to an organic photosensitizer and a preparation method thereof.

Background technique

Photosensitizers are a class of molecules that absorb light of specific wavelengths and subsequently convert the surrounding oxygen into highly reactive singlet oxygen ( ¹ O ₂ ). The main categories are porphyrins, green pigments and dyes. At present, photosensitizers have been widely used in photodynamic therapy, green organic synthesis, sewage treatment and other fields. Taking green organic synthesis as an example, in photocatalytic selective organic synthesis reactions, singlet oxygen is considered as an active species with mild oxidation ability, which appears in a variety of synthetic reactions. The most representative is that it has good selectivity in the oxidation reaction of sulfide to sulfoxide, and will not be over-oxidized to toxic sulfone substances. The reaction mechanism is that singlet oxygen reacts with one molecule of thioether to generate an intermediate product persulfoxide, and then reacts with another molecule of thioether to generate two molecules of sulfoxide products. However, the currently reported photosensitizer molecules are affected by factors such as easy aggregation, poor stability, and relatively low singlet oxygen yield. Among them, obtaining photosensitizers with high singlet oxygen yield is a major problem in green organic synthesis. There are problems of low yield and complicated synthesis method. Therefore, photosensitizers with high singlet oxygen yield are essential to promote the application of green organic synthesis.

Contents of the invention

The invention provides an organic photosensitizer and a preparation method thereof, which are used to solve the technical problems of low yield of singlet oxygen and complex synthesis methods of the existing photosensitizers.

In order to solve the problems of the technologies described above, the present invention adopts the following technical solutions:

A kind of organic photosensitizer, its molecular structural formula is as shown in formula (1) or formula (2):

In formula (1) and formula (2), n is 1 or 2.

Based on the same technical idea, the present application also provides a method for preparing the above-mentioned organic photosensitizer, which specifically includes:

When n is 1, the preparation method of the organic photosensitizer having molecular structural formula shown in formula (1) comprises the following steps:

(1) Compound B is prepared by reacting compound b1 and compound b2; wherein the molecular structural formulas of compound b1, compound b2 and compound B are shown in formula (b1), formula (b2) and formula (B) respectively:

(2) Select compound D to react with the compound B to prepare the organic photosensitizer, which is named as compound T1; wherein the molecular structural formula of compound D is as shown in formula (D):

When n is 1, the preparation method of the organic photosensitizer with molecular structural formula shown in formula (2) comprises the following steps:

Select the compound T1 to react with methyl iodide to prepare the organic photosensitizer, which is named compound T1-Me;

When n is 2, the preparation method of the organic photosensitizer with molecular structural formula shown in formula (1) comprises the following steps:

(1) Select compound a1 and compound a2 to react to prepare compound A; wherein the molecular structural formulas of compound a1, a2 and compound A are shown in formula (a1), formula (a2) and formula (A) respectively:

(2) select the compound A and compound B to prepare the organic photosensitizer by Zincke reaction, and name it compound T2;

When n is 2, the preparation method of the organic photosensitizer with molecular structural formula shown in formula (2) comprises the following steps:

(1) select described compound B to react with methyl iodide to prepare compound c1; wherein the molecular structural formula of compound c1 is as shown in formula (c1):

(2) Compound C is prepared by reacting the compound c1 with NH4PF6 _; wherein the molecular structure of compound C is as shown in _formula (C):

(3) The organic photosensitizer was prepared by selecting the compound A and the compound C through Zincke reaction in aqueous ethanol solution, and named it compound T2-Me.

Based on the same technical idea, the present invention also provides an application of the above-mentioned organic photosensitizer or the organic photosensitizer prepared by the above-mentioned method, which is used to catalyze the selective oxidation of sulfide anisole to form phenylsulfoxide, wherein the organic photosensitizer and benzene The equivalent ratio of methyl sulfide is 1:200, and a white light with a wavelength of 400-830nm is used to irradiate during the oxidation process.

Compared with the prior art, the present invention has the advantages of:

(1) The organic photosensitizer of the present invention has good water solubility, good photostability, and has strong absorption in visible light, can efficiently produce singlet oxygen, and the quantum yield of singlet oxygen can reach up to 0.65, and the organic photosensitizer molecule can catalyze The selective oxidation of sulfide anisole to non-toxic phenylmethyl sulfoxide shows broad application prospects in the field of green organic synthesis;

(2) The synthesis method of the organic photosensitizer of the present invention is simple, the yield is high, the production cycle is short, and it is suitable for large-scale industrial production.

Description of drawings

Fig. 1 is the proton nuclear magnetic resonance spectrum figure of the compound T1 of embodiment 1;

Fig. 2 is the proton nuclear magnetic resonance spectrum figure of the compound T1-Me of embodiment 2;

Fig. 3 is the proton nuclear magnetic resonance spectrum figure of the compound T2 of embodiment 3;

Fig. 4 is the proton nuclear magnetic resonance spectrum figure of the compound T2-Me of embodiment 4;

Fig. 5 is the change diagram of the ultraviolet absorption curve of the mixed solution of compound T1 and ABDA in Example 1 under the irradiation of a white light of 400-830nm;

Fig. 6 is the change diagram of the ultraviolet absorption curve of the mixed solution of the compound T1-Me and ABDA of Example 2 under the irradiation of a white light of 400-830nm;

Fig. 7 is the change diagram of the ultraviolet absorption curve of the mixed solution of the compound T2 and ABDA of Example 6 under the irradiation of a white light of 400-830nm;

Fig. 8 is the change diagram of the ultraviolet absorption curve of the mixed solution of the compound T2-Me and ABDA of Example 4 under the irradiation of a white light of 400-830nm;

Fig. 9 is the change diagram of the ultraviolet absorption curve of the compound T2-Me of Example 4 under the irradiation of a white light of 400-830nm;

Fig. 10 is a reaction process chart of the selective oxidation of sulfide anisole to sulfoxide catalyzed by the compound T2-Me of Example 4 under the monitoring of H NMR spectroscopy.

Detailed ways

The present invention will be described in further detail below in conjunction with specific examples.

Example 1:

The organic photosensitizer of the present embodiment is called compound T1, and its molecular structural formula is as shown in formula (T1):

The preparation method of the organic photosensitizer of the present embodiment, comprises the following steps:

(1) Compound B is prepared by reacting compound b1 and compound b2; wherein the molecular structural formulas of compound b1, compound b2 and compound B are shown in formula (b1), formula (b2) and formula (B) respectively:

The reaction formula is as follows:

(2) Select compound D and compound B to react to obtain compound T1; wherein the molecular structural formula of compound D is as shown in formula (D):

The reaction formula is as follows:

The compound T1 prepared in step (2) was characterized by nuclear magnetic resonance, as shown in Figure 1, the results are as follows:

¹ H NMR (500MHz, D ₂ O) δ = 9.28 (d, J = 7.0Hz, 8H, Pyridine-H), 8.95 (d, J = 6.5Hz, 8H, Pyridine-H), 8.60 (d, J = 7.0Hz, 8H, Pyridine-H), 8.47(d, J＝6.5Hz, 8H, Pyridine-H), 7.82-7.76(m, 16H, Ar-H), 4.38(s, 12H, Me-H)ppm .

Example 2:

The organic photosensitizer of the present embodiment is called compound T1-Me, and its molecular structural formula is as shown in formula (T1-Me):

The preparation method of the organic photosensitizer of the present embodiment, comprises the following steps:

Select compound T1 to react with methyl iodide to prepare compound T1-Me;

The reaction formula is as follows:

The prepared compound T1-Me was characterized by nuclear magnetic resonance, as shown in Figure 2, the results are as follows:

¹ H NMR (500MHz, D ₂ O) δ = 9.28 (d, J = 7.0Hz, 8H, Pyridine-H), 8.95 (d, J = 6.5Hz, 8H, Pyridine-H), 8.60 (d, J = 7.0Hz, 8H, Pyridine-H), 8.47(d, J＝6.5Hz, 8H, Pyridine-H), 7.82-7.76(m, 16H, Ar-H), 4.38(s, 12H, Me-H)ppm .

Example 3:

The organic photosensitizer of the present embodiment is called compound T2, and its molecular structural formula is as shown in formula (T2):

The preparation method of the organic photosensitizer of the present embodiment, comprises the following steps:

(1) Select compound a1 and compound a2 to react to prepare compound A; wherein the molecular structural formulas of compound a1, a2 and compound A are shown in formula (a1), formula (a2) and formula (A) respectively:

The reaction formula is as follows:

(2) select compound A and compound B to prepare compound T2 through Zincke reaction;

The reaction formula is as follows:

The compound T2 prepared in step (2) was characterized by nuclear magnetic resonance, as shown in Figure 3, the results are as follows:

¹ H NMR (500MHz, DMSO-d ₆ )δ: 9.57(d, J=5.5Hz, 8H, Pyridine-H), 8.94(d, J=5.0Hz, 8H, Pyridine-H), 8.83(d, J =5.5Hz, 8H, Pyridine-H), 8.18(d, J=5.0Hz, 8H, Pyridine-H), 8.14(d, J=6.5Hz, 8H, Ar-H), 8.00(d, J=6.5 Hz, 8H, Ar-H), 7.92 (d, J = 6.5Hz, 8H, Ar-H), 7.56 (d, J = 6.5Hz, 8H, Ar-H) ppm.

Example 4:

The organic photosensitizer of the present embodiment is called compound T2-Me, and its molecular structural formula is as shown in formula (T2-Me):

The preparation method of the organic photosensitizer of the present embodiment, comprises the following steps:

(1) Select compound B to react with methyl iodide to prepare compound c1; wherein the molecular structural formula of compound c1 is as shown in formula (c1):

The reaction formula is as follows:

(2) Compound C is prepared by reacting compound c1 with NH ₄ PF ₆ ; wherein the molecular structure of compound C is shown in formula (C):

The reaction formula is as follows:

(3) Select compound A and compound C to prepare compound T2-Me through Zincke reaction in ethanol aqueous solution;

The reaction formula is as follows:

The compound T2-Me prepared in step (3) was characterized by nuclear magnetic resonance, as shown in Figure 4, the results are as follows:

¹ H NMR (500MHz, D ₂ O) δ: 9.35 (d, J = 6.5Hz, 8H, Pyridine-H), 9.01 (d, J = 6.5Hz, 8H, Pyridine-H), 8.65 (d, J = 6.5Hz, 8H, Pyridine-H), 8.53(d, J=6.5Hz, 8H, Pyridine-H), 8.00(d, J=8.5Hz, 8H, Ar-H), 7.85(d, J=8.5Hz ,8H,Ar-H),7.77(d,J=8.5Hz,8H,Ar-H),7.63(d,J=8.5Hz,8H,Ar-H),4.44(s,12H,Me-H) ppm.

The organic photosensitizer (compound T2-Me) of the present embodiment is detected the photostability under the white light irradiation of 400-830nm with absorptiometry, concrete operation is:

Add compound T2-Me to 4 mL of distilled water, control the concentration to 1.00×10 ^-5 mol·L ^-1 , then irradiate with a white light of 400-830 nm, and use a UV-visible spectrophotometer to detect the characteristic absorption of T2-Me that increases with the irradiation time peak change. The results are shown in Figure 9. The results showed that the UV absorption curve of T2-Me did not change significantly after being illuminated for 40 minutes, which indicated that it had good photostability.

The organic photosensitizer (compound T2-Me) of the present embodiment is tested for the ability of catalyzing the selective oxidation of sulfide anisole to sulfoxide phenylene in the aqueous phase, and the specific operation is:

In 400uL of deuterated water (D ₂ O), add photosensitizer T2-Me (control the concentration to 5.0×10 ^-5 mmol) and sulfide anisole (control the concentration to 1.0×10 ^-2 mmol), pass through oxygen and use Irradiate with a white light of 400-830nm, and monitor the progress of the reaction by proton nuclear magnetic resonance. The results are shown in Figure 10. As can be seen from Figure 10, the organic photosensitizer of the present embodiment produces singlet oxygen under light to oxidize thioanisole into sulfoxide, which shows that it has a wide range of applications in the field of green organic synthesis. application prospects.

The organic photosensitizer (compound T1, compound T1-Me, compound T2 and compound T2-Me) of embodiment 1-4 is used to detect the ability of producing singlet oxygen under the white lamp irradiation of 400-830nm by absorptiometry, specific operation for:

Add compound T1, compound T1-Me, compound T2 and compound T2-Me to 4 mL of distilled water respectively, and mix with singlet oxygen indicator 9,10-anthracendiyl-bis(methylene)dimalonic acid (ABDA) It is configured as a mixed solution, and the concentration of the control sample is 1.00×10 ^-5 mol·L ^-1 , and the concentration of ABDA is 1.50×10 ^-4 mol·L ^-1 . The mixed solution is irradiated with a white light of 400-830nm, and the change of the characteristic absorption peak of ABDA with the irradiation time is detected by a UV-visible spectrophotometer. The results are shown in Figures 5-8, and the results show that the characteristic absorption peak of ABDA decreases with the increase of illumination time, which indicates that the organic photosensitizer of the present invention can generate singlet oxygen.

Taking the organic photosensitizer (compound T2-Me) of Example 4 as an example, the singlet oxygen quantum yield of the organic photosensitizer is tested, and the specific operations are:

Using ABDA as an indicator to detect the ability of compound T2-Me to generate singlet oxygen under white light irradiation, ^ABDA (concentration controlled at 1.5×10 ^-4 mol/L) and T2-Me (concentration controlled at 5.0×10 L) The aqueous solution is mixed and then exposed to white light irradiation (400-830nm). The absorbance decrease of ABDA at 378 nm was recorded at different irradiation times. Taking rose bengal (RB) as a standard photosensitizer as a comparison, the ¹ O ₂ quantum yield (Φ _o ) of T2-Me in water was calculated using the following formula:

Φ _T2-Me = Φ _RB × K _T2-Me × A _RB /(K _RB × A _T2-Me );

where K _T2-Me and K _RB are the rate constants for the decomposition of ABDA by T2-Me and RB. A _T2-Me and A _RB represent the light absorption of T2-Me and RB, determined from the integration of the absorption bands in the wavelength range of 400–830 nm. ^ΦRB is the _1O2 quantum yield of _RB , which is 0.75 in water. The calculated ¹ O ₂ quantum yield of T2-Me in water is 0.65.

The above descriptions are only preferred implementations of the present invention, and the scope of protection of the present invention is not limited to the above examples. For those skilled in the art, improvements and transformations obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

Claims (3)

1. An organic photosensitizer, characterized in that the molecular structural formula of the organic photosensitizer is shown as formula (1) or formula (2):

in the formulas (1) and (2), n is 1 or 2.

2. A method for preparing the organic photosensitizer of claim 1, wherein when n is 1, the method for preparing the organic photosensitizer having the molecular structural formula represented by formula (1) comprises the steps of:

(1) A compound B1 and a compound B2 are selected to react to prepare a compound B; wherein the molecular structural formulas of the compound B1, the compound B2 and the compound B are respectively shown as a formula (B1), a formula (B2) and a formula (B):

(2) Selecting a compound D to react with the compound B to prepare the organic photosensitizer, and naming the organic photosensitizer as a compound T1; wherein the molecular structural formula of the compound D is shown as the formula (D):

when n is 1, the method for preparing the organic photosensitizer having the molecular structural formula shown in formula (2) comprises the following steps:

the compound T1 is selected to react with methyl iodide to prepare the organic photosensitizer, and the organic photosensitizer is named as a compound T1-Me;

when n is 2, the method for preparing the organic photosensitizer having the molecular structural formula shown in formula (1) comprises the following steps:

(1) A compound a1 and a compound a2 are selected to react to prepare a compound A; wherein the molecular structural formulas of the compound a1, the compound a2 and the compound A are respectively shown as a formula (a 1), a formula (a 2) and a formula (A):

(2) Selecting the compound A and the compound B to prepare the organic photosensitizer through a Zincke reaction, and naming the organic photosensitizer as a compound T2;

when n is 2, the method for preparing the organic photosensitizer having the molecular structural formula shown in formula (2) comprises the steps of:

(1) The compound B is selected to react with methyl iodide to prepare a compound c1; wherein the molecular structural formula of the compound c1 is shown as the formula (c 1):

(2) Selecting said compounds c1 and NH ₄ PF ₆ Reacting to prepare a compound C; wherein the molecular structural formula of the compound C is shown as the formula (C):

(3) And selecting the compound A and the compound C to prepare the organic photosensitizer in an ethanol water solution through a Zincke reaction, and naming the organic photosensitizer as a compound T2-Me.

3. The use of the organic photosensitizer of claim 1 or the organic photosensitizer prepared by the preparation method of claim 2, wherein the organic photosensitizer is used for catalyzing the selective oxidation of the methyl sulfide to form the methyl sulfide, wherein the equivalent ratio of the organic photosensitizer to the methyl sulfide is 1:200, irradiating by a white lamp with the wavelength of 400-830nm in the oxidation process.

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