Liu Feng lacks this kind of ability compared to his graduate students.

It can be said that he has already integrated the knowledge of theory, and what he lacks is the ability to apply theory to practical experiments and solve practical problems.

Theoretical knowledge is higher than practical knowledge, which is his biggest shortcoming now, and of course, it is also the shortcoming of many top students.

This shortcoming will be made up to a certain extent when he does his graduation project in the last semester of college, but Liu Feng thinks that he can't wait that long.

In his opinion, a student who can't skip a grade is not a real student, and in 1 year, if he can't complete his graduation project, he's sorry for opening such a hanging.

Back to the experiment at hand.

Liu Feng found that the synthesis method of the target compound is generated by the addition reaction of a group on one branch of the starting material intermediate with another compound group, well, it doesn't seem to be that complicated!

However, it seems that there are not too many side reactions in this one-step reaction.

Because there are many branches of intermediates and target compounds, Liu Feng found that in addition to the more than 10 major side reactions listed in the data, in addition, he also listed a bunch of them in the draft book, and even if he continued to list, he could list them until dawn the next day!

No wonder this female senior brother's temper is so hot, anyone who sees such a long list of side reactions may not be in a good mood, alas......

Liu Feng sighed, probably knowing the difficulty of this synthesis experiment.

According to the experimental design plan, it is obvious that the final target chemical must be able to be synthesized, but the key thing is how much yield can there be, how many by-products can there be, what are the by-products, and can the amount of them be controlled? There are too many extraneous things.

This not only involves the control of a series of environmental factors such as temperature, pressure, reaction time, catalyst and so on in the experiment, but also the selection of experimental conditions.

For example, what Liu Feng needs to do is to raise the temperature by 20°C every half hour for 5 minutes at the starting temperature, while maintaining it for 10min until it finally rises to 180°C, and then react for another 2 hours, while controlling the pressure to remain unchanged and the amount of catalyst to remain at 1mol/L.

Shaking his head, it's too complicated.

Looking up at the buddy on the side, if he guessed correctly, this guy's experimental procedures should be similar to his, but I don't know if it's pressure or other single environmental factors.

frowned, he had completely memorized the principles and steps of this set of experiments, but until now, Liu Feng still had a problem that he couldn't understand.

"Senior Brother Zhong, I have a question for you!" So, he asked cheekily.

"Say it!" Zhong Jing has always liked to train Xiao Mengxin, and when he was in school, he was very patient with his few junior disciples, and there was naturally no shortage of guidance and help.

"That's right, I've written down the principle and process of this experiment, but there's one more question, what was the purpose of our original design of this experiment?"

"Huh?" Zhong Jing was surprised when he heard Liu Feng's inquiry, "You said that you understand the principles and steps of the experiment?"

"Yes. Liu Feng lifted his glasses and nodded confidently.

Zhong Jing stared at Liu Feng in surprise, and looked at him very much, thinking that a freshman student could understand the experimental principle here, could it be bragging!

You know, this set of experiments involves a series of additions, substitutions, rearrangements and other principles, and many knowledge points will not be learned until at least the sophomore year, and he will be a freshman now?

"Okay, then tell me, here, why does this side reaction occur, and what are the knowledge points involved?" Obviously, Zhong Jing didn't believe it, and pointed to a side reaction on the data.

If it were Wen Ruonan, who had a hot temper, maybe he would have driven Liu Feng out directly.

"Obviously, this is a typical Claisen ester condensation reaction, the principle of which is that the ester containing α-hydrogen undergoes condensation under the action of an alkaline condensation agent such as sodium alcohol, and the alcohol that loses a part gets β-ketoate ester......" Liu Feng didn't think about it, and blurted out the answer.

"What about this side reaction?" Zhong Jing was a little convinced, this guy really answered correctly.

"This is the Micheal addition reaction, the principle is ......"

……

One question after another, Liu Feng answered all of them correctly, which can be called a quick thinking.

Zhong Jing also had to admire that a freshman had mastered organic chemistry to such an extent - the knowledge points of each chapter were included, and the theoretical knowledge he mastered was almost no worse than that of their graduate students!

Subconsciously, Zhong Jing was a little afraid of this guy.

This kid is so powerful in his freshman year, and he won't be able to turn the sky up in the future?

If this guy has mastered all the steps from design, operation to completion of experiments, and can even complete a set of processes for the compilation of a thesis alone, I am afraid that some people will believe him if he is a graduate doctoral student!

Is this really just a freshman in college, and what were you doing in your freshman year?

Alas, ashamed, ashamed!

Looking at the young junior brother in front of him, all of a sudden, Zhong Jing had the feeling that he had learned from a dog in his four years of college.

"Okay!" Zhong Jing looked at the talkative little junior brother in front of him speechlessly, and quickly changed the topic, he was afraid that if he asked again, his little heart would not be able to bear this blow.

Is the current freshman and the little budding so powerful?

"What did you just say?" Shaking his head, leaving all the thoughts that hit him behind, Zhong Jing asked.

Liu Feng was very puzzled, why the people who have been in contact with him recently always like to wander: "That's the case, I want to ask what was the purpose of our original design of this experiment?"

"Well, that's right. Zhong Jing touched his chin, recalled that when he designed the experiment, he straightened out his thoughts and said, "I'm sure you have more or less guessed it." Our goal was to synthesize this target product and increase its yield as much as possible, but the biggest challenge now was that the yield of the product was far from what we expected!

Therefore, we are now actively looking for the main factors affecting the synthesis of products, from temperature, pressure to operation time, etc., this series of univariates should be taken into account, and the univariate control experiment is allocated, and your set of experiments is the univariate control of temperature. ”

"I see!" Liu Feng nodded, indeed exactly in line with his conjecture!

As long as the occurrence of side reactions can be controlled, and the reaction raw materials are used for the synthesis of the target product to the greatest extent, then the yield of the product can be expected.

And what about controlling the side reactions? This involves the control of the reaction conditions.

"So Senior Brother, what is the highest yield of our target product so far?" Liu Feng continued to get to the bottom of it.

"We designed an acceptable yield of 68.0 percent, but as of this morning, the highest yield we got was only 21.9 percent, which is not too far off!" Zhong Jing sighed, and his face couldn't help but show a trace of exhaustion.

After months of fighting, they are only short of this last kick at the door, but they can't get through, it's really a long way to go!

"Yes, there is a long way to go!"

Liu Feng expressed deep sympathy for Senior Brother Zhong and what happened to them.

In fact, academic research is so~, if you are unlucky, God knows when you will be able to produce results! After all, this is not only an academic problem, I am afraid it is also a matter of luck; unless someone opens it, it is impossible to do it in one step.

But when it comes to hanging, hey, can't he Liu Feng open it?