I Have a Research Support System

In the process of product separation and purification, the rotary steaming operation lags behind the passing through the column.

Therefore, after Xu Qiu and Han Jiaying exchanged the division of labor, Xu Qiu got some free time.

He went back to the office to drink some water, and then went to solve his physical problems. He just happened to meet Chen Wanqing who was going to deal with the reaction, so he followed him.

On the way, the senior sister took the initiative to introduce: "My reaction is divided into two steps. The first step is to react with n-butyllithium to form a metal lithium reagent. The second step is to react with an aldehyde reagent such as DMF to form an aldehyde group."

"Well," Xu Qiu nodded, "the first step is to extract hydrogen from n-butyllithium to produce carbanion, and the second step is to attack the aldehyde group of DMF, and the dimethylamino group leaves to form the target product." Rough reaction mechanism He can still deduce it. How can I say that he also got two A's in "Organic Chemistry" in the two semesters of his sophomore year.

"How do you know so clearly? Could it be that you checked the information in advance?" Chen Wanqing said in surprise.

"No, you can figure it out after a little analysis." Xu Qiu replied casually while putting on his lab coat.

"Okay," Chen Wanqing slammed her mouth, "I have almost returned all the knowledge I learned in college to the teacher. It took me a while to prepare this reaction, including checking the literature on the reaction mechanism, and posting it on the little tree worm. I have half a day."

Walking into the laboratory, Xu Qiu glanced at the situation on the side of the liquid chromatograph from a distance. The blank silica gel column was still white, and no product came down. The junior girl should be able to handle it alone, so she followed the senior sister to the fume hood .

The redistillation device is still there, but the solvent inside is no longer tetrahydrofuran, but N,N-dimethylformamide DMF.

Now that the re-distillation and cooling have been completed, a lot of solvents are stored in the solvent distillation head. When DMF needs to participate in the reaction, it must be re-distilled in an anhydrous and oxygen-free environment before it can be used.

Chen Wanqing used a syringe to absorb the re-distilled DMF, and then injected it into the reaction container, saying: "After that, there is no need to add liquid nitrogen to keep the temperature low, just let it heat up naturally."

"Then how do we deal with the remaining n-butyl lithium?" Xu Qiu asked.

"In the information I have checked, some say to quench it directly with water, some say to use ethanol, and some say to use saturated ammonium chloride or sodium chloride aqueous solution. There are different opinions." Chen Wanqing smiled, "I plan to use saturated chlorine Aqueous ammonium chloride solution, anyway, I only added 500 mg of material, although n-butyllithium was added at 4.4 times the equivalent, but the residue should not be much."

Xu Qiu nodded. Although the whole low-temperature reaction was performed by the senior sister, he was watching the whole process and had memorized the experimental process and various precautions.

If the senior sister responds successfully this time, if he wants to use it later, he can directly use this as a template instead of re-exploring it himself.

Next, after adding DMF to the reaction bottle, Chen Wanqing collected some redistilled DMF solvent into a small 10ml reagent bottle, and then she began to prepare nitrogen balloons, new reaction bottles, etc., obviously intending to Vote for second response.

He didn't seem to have anything to do here, Xu Qiu was about to leave when he suddenly heard his junior call: "Senior brother, come quickly~" He hurried over.

Han Jiaying said weakly: "Brother, I adjusted the polarity faster, and then the first point and the second point are not separated..."

Xu Qiu picked up the spot plate corresponding to the fifth test tube and glanced at it. There were two sample points on it, one deep and one shallow, corresponding to the first product and raw material.

'The two points are very close, and it is more difficult to separate the two products I have dealt with before. No wonder the school girls overturned. '

'If this sample is given to me, it will probably be better. '

‘However, when assigning tasks, I didn’t think too much about it, so I came directly according to the sample number. '

'The matter has come to this, let's find a way to remedy it. '

"Don't worry," Xu Qiu thought for a while and said, "Just keep the current polarity, wash down the two products together, then collect the pure second product, and finally mix the first product and the raw material again, Pillar again."

"Oh, okay," Han Jiaying whispered, "That's the only way to go."

"Don't take it too seriously. It's not common for experiments to fail." Seeing her downcast look, Xu Qiu comforted her again: "Actually, I can't blame you. Today's products are relatively close. Just apply yesterday. experience, that’s what happens.”

"Yes," Han Jiaying nodded, "The speed of my polarity increase is the same as yesterday. At that time, when I saw two red balls coming down one after another, I felt something was wrong. I wanted to turn back the polarity, but it was too late."

"However, our luck is not bad. The first product and raw materials are relatively shallow two points,"

"Yeah, it's a blessing in misfortune."

Afterwards, Xu Qiu collected the second product, steamed it to obtain the product, and then personally separated the mixed sample of the first product and the raw material. It took less than an hour more and successfully obtained two pure products.

Chen Wanqing handled the first reaction and voted for the second reaction.

The time also came to six o'clock in the evening, dinner time.

Before Xu Qiu left the laboratory, he copied the six products obtained from the three reactions, including the crude product obtained from the first reaction of his senior sister, into the simulation laboratory and handed them over to the simulation experimenters for analysis.

At the same time, I also checked the results of the simulation experimenters today:

Now the efficiency based on the simple PDI molecule has been optimized to 3.61%, which is very close to the highest value of 4.0% reported internationally.

Xu Qiu's inner analysis:

In less than a day, hundreds of devices have been made, and the efficiency of the simulation experimenters is quite high.

Of course, this is also related to my transformation of the simulation laboratory. Now more than ten evaporation machines have been integrated in the simulation laboratory, which can make more than ten batches of devices at the same time.

Even the points are consumed quickly. Since the opening of the simulation laboratory II, it has already spent almost 2000 points.

2,400 points a day, 16,800 points a week, I have less than 50,000 points, if I keep turning it on, it will be emptied within a month.

How can this work?

Hmm... The upper limit of the current simple PDI molecule is too low, you can stop exploring the performance of their devices first, and start with a better system in the future.

Thinking of this, Xu Qiu decisively changed the simulation experimenter's instructions and removed the device optimization part.

Only basic characterization tests on the purity and composition of new materials remain, such as infrared spectroscopy, mass spectrometry, elemental analysis, nuclear magnetic resonance, etc.

These are the experiments he has to do now, which are related to his further experiments.

The raw material for the next reaction is a monobromine-substituted PDI molecule, but he is still unable to judge the corresponding situation of the two products.

If you go to the school’s public instrument platform to send samples for testing, and wait until you get the analysis results before proceeding to the next step of reaction, it may take a week.

No way, it is so troublesome to do experiments related to the synthesis of small organic molecules.

A new material that can be published. If you can produce a pure product in a month, the boss will praise you for your high efficiency.

...

After dinner, A501 office.

Han Jiaying stretched and yawned, "I'm so tired these days."

Xu Qiu was also infected by her. He covered his mouth when he realized it, and echoed, "Well, tomorrow we both have a day off for experiments, and it happens that senior sister can do liquid chromatography to separate and purify today's products. How about it?" After finishing speaking, he turned to He looked at Chen Wanqing.

"Of course I have no objection." Chen Wanqing nodded and added, "But Xu Qiu, you have to come and help, just watch from the sidelines. I don't have much experience in crossing pillars."

"Okay, no problem." Xu Qiu had no objection.

Han Jiaying lay on the sofa, changed her posture, and complained: "I agreed to write a review when I was free from the experiment, but I have been in Zhangjiang for almost a week, and I haven't moved a word."

"I haven't moved a single word." Xu Qiu sighed, "The intensity of the experiment can be reduced appropriately, otherwise the long-term high-intensity experiment will be too much for the body, that is, I have just returned from vacation.

By the way, senior sister, how is your writing? "

"I..." Chen Wanqing looked hesitant.

"Senior sister is not chasing dramas, is she?" Xu Qiu tentatively asked.

"Hey, after the experiment failed in the morning, I wanted to watch half an episode to refresh my mood, but I accidentally watched... three episodes."

"Okay." In Zhang Jiang's laboratory, the sky is high and the boss is far away. It is indeed easy to make people worry about paddling.

The three rested in the office, chatted for a while, and continued their new journey.

The school bus at nine o'clock now has only two hours left.

Entering the laboratory, Han Jiaying and Xu Qiu continued to use columns and rotary evaporation to separate and purify the products.

Chen Wanqing added DMF to the second reaction, using the DMF collected in the small bottle after re-distilling before, which saved the time of re-distilling again.

Subsequent experiments went smoothly without any surprises.

It's just that the time is a little bit rushed. After closing the laboratory, the three of them trotted all the way to the school bus waiting point with their schoolbags on their backs.

It turned out that it was 8:58, and the school bus hadn't arrived yet.

"Huh~huh~" Han Jiaying supported her waist with one hand, panting with a blushing face, "I... know, I just slowed down and ran slowly."

"Sister, you are lacking in exercise," Xu Qiu suggested, "Do you want to make an appointment tomorrow morning to exercise early together?"

"It's hard to take a day off tomorrow." Han Jiaying tilted her head and asked tentatively, "How about next time?"

"It's up to you," Xu Qiu shrugged helplessly, then turned his head and said, "Sister, how is your reaction? It's going well."

In fact, he had already obtained the results in the simulation laboratory in advance. The senior sister's reaction was successful, with a yield of about 50%-70%, and the separation was not difficult.

"Hm... not sure yet," Chen Wanqing paused and said, "The result of the panel is one dark, one light, one very light, and one light is the raw material. I hope the dark one is the product I want, not very light. the one."

"Don't think so, the dark one is your product." Xu Qiu said in an affirmative tone.

"I would like to borrow your good words." Chen Wanqing only responded with a smile as a comfort.