To investigate the activity of VO(a

To investigate the activity of VO(acac)2 as a catalyst for oxidation, students used different reaction conditions determined in the class discussion during the first week.
The individual data generated from the catalysis reactions were shared by the entire class.

While the reaction was refluxing, the students examined the catalyst in different solvents. A portion of the third lab period was required for purifying the oxidation products and recording yields.

’EXPERIMENTAL DETAILS
The preparation of VO(acac)2 was based on a known procedure1 and modified to use VOSO4 as the starting material (Scheme 2).
The synthesis involved dissolving VOSO4 in water,adding 2,4-pentanedione, and then adding an appropriate base.
We used saturated Na2CO3 solution and students continued to add this solution until there was no effervescence upon further addition.
The solid product was filtered off and washed with water.


The solid was allowed to dry on the filter before being collected and stored in a sealed sample vial.
The product was characterized by infrared (IR) spectroscopy.
For the oxidation reactions, VO(acac)2 and anthracene were placed in a round-bottom flask and dissolved in ethyl acetate (Scheme 1).
To this was added hydrogen peroxide and the reaction was allowed to proceed at the desired temperature for 2 h. When the reaction was done, water was added and the organic layer removed.
The water layer was then extracted with chloroform or dichloromethane and the organic solution was combined with the ethyl acetate.

The organic solvents were evaporated to isolate the solid product, which was then washed with toluene and allowed to dry.
The product was collected, weighed, and then analyzed by thin-layer chromatography (TLC) using standard samples of anthracene and anthraquinone, running three spots side by side on the same plate.

An ultraviolet (UV) lamp was used to visualize the spots on the TLC plate. If the product was not pure, further washings with toluene were performed until the TLC showed pure product.อัลตราไวโอเลต (UV) โคมไฟที่ใช้เพื่อให้มองเห็นจุดบนแผ่น TLC หากสินค้าไม่ได้บริสุทธิ์ซักต่อไปด้วยโทลูอีนได้ดำเนินการจนTLC แสดงให้เห็นว่าผลิตภัณฑ์ที่บริสุทธิ์

The capacity for the 5-coordinate structure to accommodate an additional ligand can be demonstrated by dissolving the compound in coordinating solvents such as pyridine or solutions
containing aqueous ammonia or sodium carbonate.ความสามารถในการประสานงาน 5 โครงสร้างรองรับ
แกนด์เพิ่มเติมสามารถแสดงให้เห็นโดยการละลายสารประกอบตัวทำละลายในการประสานงานเช่นไพริดีนหรือการแก้ปัญหามีแอมโมเนียน้ำหรือโซเดียมคาร์บอเนต
Coordination of a sixth ligand changes the color compared to solutions in noncoordinating solvents such as chloroform or dichloromethane. การประสานงานของแกนด์ที่หกเปลี่ยนสีเมื่อเทียบกับการแก้ปัญหาใน
ตัวทำละลาย noncoordinating เช่นคลอโรฟอร์มหรือไดคลอโรมีเทน

ผลลัพธ์ (ไทย) 3:

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