I Have a Research Support System

After resting on the sofa for a while, Xu Qiu went to the drug warehouse to return the cart.

He took Chen Wanqing's one-card, because his one-card has not opened the access control yet.

Returning to the microelectronics building again, he copied A501-503 into the simulation laboratory.

The current level 2 simulation laboratory has a space of 1,000 cubic meters, and it has already occupied more than half of it.

No way, Zhang Jiang's synthesis laboratory is really too big, covering an area of ​​nearly 200 square meters.

In the laboratory, Chen Wanqing had already put on her lab coat and was fiddling with the supplies she had just received.

Seeing Xu Qiu come in, she said:

The chemical laboratory here is more dangerous, so the protective measures have to be stricter.

I usually wear four layers of gloves, the innermost layer of PE gloves, a small rubber glove on the outside, and a large rubber glove on the outside.

Because there may be silty particles such as talcum powder on the rubber gloves, it is necessary to put a layer of PE gloves on the outermost layer to prevent contamination of reagents or reaction containers.

Wear a respirator if large amounts of solvents or highly toxic reagents are to be used.

Like now, there is no need for a gas mask for the time being, and a disposable activated carbon mask can be used.

Because wearing a gas mask will be very stuffy, and the voice will be reduced, which is not convenient for communication.

In addition, the gloves should cover the cuffs of the lab coat to prevent medicine from entering the clothes from the cuffs. For this reason, I also specially used a lab coat with elastic bands on the cuffs.

Xu Qiu nodded, then imitated his senior sister and took protective measures.

That's right, Chen Wanqing looked Xu Qiu up and down, then pointed to several unopened cardboard boxes, and said:

Over there are the reagents I ordered before, mainly some solvents. Duan Yun helped to sign for them last week. Go and take them apart and put them in the reagent cabinet.

Okay. Xu Qiu found a pair of scissors, cut the packing tape outside the carton, and opened the box.

There are solvents in brown glass bottles and plastic barrels, both of which are from Sinopharm.

Among them, toluene and n-octane are packed in 500ml bottles, and anhydrous methanol, acetone, and absolute ethanol are all packed in 4-liter barrels.

In addition, there are two 500g boxes of sodium hydroxide and two one-litre tubs of simethicone.

In addition to the carton, there is also a foam box containing an ice box and empty dry ice packs that appear to have been shipped refrigerated.

There are several small reagent bottles inside the foam box, and their outer packaging is sealed with black plastic, with Chinese and English labels on the side.

Tetra(triphenylphosphine) palladium, Xu Qiu read out, and after thinking for a moment, he said:

It seems to be a catalyst, I have seen it in the literature.

That's right, the coupling reaction we do needs to use zero-valent palladium as a catalyst, and triphenylphosphine as a ligand. Chen Wanqing said:

This needs to be refrigerated at minus 20 degrees Celsius to four degrees Celsius, but if you want to use it later, put it outside first, and put it in the refrigerator when you're done using it.

After Xu Qiu sorted out the medicines, Chen Wanqing started the experimental teaching:

The solvent used in the Stille coupling reaction is toluene, and the purchased toluene cannot be used directly, and it needs to be re-distilled before use.

Because the purchased toluene will contain traces of water and other impurities.

Water molecules will react with trimethyltin-containing monomers, making detinning ineffective, causing the material ratio of the two raw materials in the polymerization reaction to no longer be 1:1, thereby reducing the molecular weight of the obtained polymer.

As for the polymer materials we need, under the condition of ensuring solubility, the higher their molecular weight, the better.

Judging the success of a synthetic reaction mainly depends on the molecular weight of the product. Generally, the number average molecular weight is preferably between 20,000 and 70,000.

After the introduction, she began to set up the experimental equipment in the fume hood.

Because the toluene solvent distilled from this device is enough for two people to use, there is no need to build it twice.

After Xu Qiu copied her skills, she learned from the system video while standing by and watching the seniors.

At the bottom is a magnetic constant temperature heating stirrer, which can control the temperature of the reaction and the speed of the magnetic stirring bar.

There is an oil bath on the stirrer, which is filled with simethicone oil, which can be used below 200 degrees Celsius to ensure a constant temperature and even heating.

Above the oil bath, the senior sister fixed a round-bottomed flask with clips so that two-thirds of its volume was submerged in simethicone.

Then, in the neck above the round bottom flask, insert a solvent distillation head.

Insert another bulb condenser on the solvent distillation head.

Insert a three-way valve with a balloon on the spherical condenser.

The bottle mouth of each glassware is fixed with iron clips.

Then, she installed a condensate pipe on the spherical condenser pipe, connected it with a rubber hose according to the method of inlet at the bottom, and out at the top, and fixed it with a cable tie.

The form is roughly: faucet-hose-condensation pipe lower opening-condensation pipe upper opening-hose pipe-sewer.

After the device is set up, including the height of the fume hood table, it is taller than a person.

It's finally finished. Chen Wanqing said.

Senior, wait a minute, I have a question, Xu Qiu asked:

Aren't we redistilling toluene? What about toluene?

Oh, I forgot to add it. Chen Wanqing said in embarrassment.

She took the reagent bottle of toluene, disassembled the connection between the round bottom flask and the solvent distillation head, then pulled the door of the fume hood down, and poured about 250 ml of toluene.

Next, we need to use sodium wire to remove water and use benzophenone indicator.

Sodium wire? Xu Qiu asked suspiciously, Is it metallic sodium?

Yes, the reaction between benzophenone and sodium metal forms a blue intermediate. Chen Wanqing said:

If there is water in the solvent, it will continue to react to form a colorless compound, and if there is no water, it will stay in the blue state of the intermediate.

She took out the box of sodium metal from the reagent cabinet.

Sodium metal is very reactive and needs to be stored in kerosene.

She spread several layers of toilet paper on the laboratory table, then used long tweezers to pick up a piece of sodium, then cut a small piece with a knife, and put the remaining sodium piece back into the kerosene.

Then, she cut the sodium block into filaments with a knife, blotted the kerosene on the surface with paper, and put the sodium filaments into a round-bottomed flask.

Finally, to the round bottom flask, add benzophenone twice with a stainless steel spatula, and then add a magnetic shuttle bar.

It should be fine now. Chen Wanqing said.

Senior, wait a minute, I have another question, Xu Qiu asked:

What's the use of the blue balloon we're wearing above?

This can be made into a nitrogen balloon to ensure that the entire closed distillation system is a nitrogen atmosphere. Chen Wanqing said:

If you simply redistill the toluene, you don't need to add nitrogen balloons.

But let's have one, after all, safety comes first.

First of all, it is necessary to ensure that the air content in the nitrogen balloon is extremely low, so it needs to be repeatedly filled and discharged with nitrogen.

Chen Wanqing took off the balloon connected to the three-way valve, and connected one end of the three-way valve to the nitrogen hose.

Then, she slowly unscrewed the nitrogen valve.

Wait, why doesn't it get angry? Chen Wanqing wondered.

Xu Qiu shook his head, thinking:

Sure enough, a laboratory with a senior is always full of surprises.

Thanks to try2016 for the 100 starting coins, and Xianyu Xingyushan and Wei Weiyong for the 200 starting coins.