[experimental operation welfare] safe access (small amount & large amount) operation steps of n-butyl lithium

N-butyl lithium English Name: butyllithium; n-butyllithium CAS: 109-72-b formula: C4H9 Li molecular weight: 64.05 property: density 0.68 boiling point: 60-80 ℃ flash point: - 21 ° C The pure product is white powder, with strong reducibility It is easy to burn when encountering water and oxidant It is mainly light brown liquid, which is soluble in saturated hydrocarbon solutions such as n-hexane, cyclohexane and benzene Hazard characteristics: the chemical reaction activity is very high, and it will catch fire in contact with air Contact with water, acids, halogens, alcohols and amines will cause severe reaction and explosion First aid measures: skin contact: immediately remove the contaminated clothes and wash with a large amount of flowing clear water for at least 15 minutes Seek medical advice Eye contact: lift the eyelid immediately, and wash thoroughly with a large amount of flowing clear water or free saline for at least 15 minutes Seek medical advice Inhalation: quickly leave the site to fresh air Keep respiratory tract unobstructed If breathing is difficult, give oxygen If breathing stops, perform artificial respiration immediately Seek medical advice Ingestion: rinse mouth with water if taken by mistake, and give milk or egg to drink Seek medical advice Fire fighting method: fire fighters must wear full body fire and gas protective clothing Fire agent: dry powder, sand It is forbidden to use water, foam or halide fire agent [basic knowledge] how to measure butyl lithium safely? Principle: all methods are to ensure that there is no water or oxygen in the system, that is, no contact with water or oxygen during use Experiments of similar properties such as butyl lithium can only be carried out on the premise of ensuring safety and favorable escape 1 Before the experiment, clean the glass instrument, mixing rod, tetrafluorocarbon head, etc which are ready to be used, dry them at 120 ℃ for more than 2 hours, and then cool them for use It is now used for drying If it is not used for a long time after drying, it needs to be dried again before use Note: thermometers, plastic tubes, etc cannot be dried 2 Before the experiment, it is necessary to clear the site and clear the surroundings of the place where the experiment is to be carried out, so as to prevent the influence of escaping in time in case of danger There shall be no acid substances or inflammable and explosive substances around the experiment The ground and operation platform shall be dry without water or solvent to prevent foot slipping during escape 3 In a reasonable place around the experimental location, fire apparatus, fire sand and other fire-fighting equipment shall be accurately arranged in case of no fire 4 When feeding, calculate the feeding amount according to the amount of butyl lithium, and try to use up all the whole package of butyl lithium at one time After the butyl lithium is used up, the fine eye needle can be installed on the butyl lithium package to slowly decompose the remaining butyl lithium Butyl lithium bottles should not be put into water or fire 5 In the laboratory, N 2 or ar 2 should be fully replaced in the system to ensure there is no air before adding butyl lithium 6 In general, the exothermic reaction of butyl lithium is violent, so the appropriate cooling device should be selected 7 Generally, a small amount of butyl lithium can be used, and a needle tube with good sealing performance can be used Take n 2 or ar 2 into the tube, repeat for more than three times, then press it into a butyl lithium bottle, and then take out the required amount of butyl lithium 8 A large number of butyl lithium can be used to carry the charging device in the following ways However, an alkaline drying tower is needed before the protective gas contacts with butyl lithium Different experiments require different temperatures, such as - 78 ℃, - 30 ℃ and 0 ℃ Experience: when taking n-butyl lithium, pay attention not to enter the air After taking the needle, pull it out in the atmosphere of nitrogen injection, and seal the needle mouth with wax Make sure there is no water or oxygen N-butyl lithium is inflammable Do not spill it out during operation All reaction instruments should be dry and the solvent should be re evaporated First, insert the nitrogen balloon into the n-butyl lithium bottle stopper, and then pump it with a syringe Finally, pull out the balloon and seal the pinhole on the n-butyl lithium bottle stopper with wax Secretly tell you: the laboratory must be equipped with candles + matches yo! [experimental operation welfare] the following is the operation procedure of taking and using a small amount of n-butyl lithium: the n-butyl lithium is extremely alkaline, its chemical property is very active, and the reaction with the substrate will be quite intense, so the whole reaction must be carried out under low temperature and inert gas We do not recommend using a glass constant pressure funnel in the laboratory for the feeding operation of organometallic reagents In the experiment, the reaction device needs to be dried, the solvent needs to be anhydrous, and the transfer syringe and the double headed needle also need to be dried It is suggested to use the syringe with screw or bayonet to fix the needle, so as to prevent the leakage of liquid from causing danger In order to prevent the reagent bottle from falling when the syringe is extracting n-butyl lithium, it is necessary to fix the reagent bottle to avoid danger The bottle mouth package of n-butyl lithium from regular manufacturers is sealed with rubber gasket, which is convenient for inert gas protection and syringe use while ensuring safety and reagent quality In order to prevent leakage of n-butyl lithium extracted from syringe, polytetrafluoroethylene raw material belt shall be used for fixation at syringe and needle, and tape and sealing film which are easy to be corroded by n-butyl lithium shall not be used Before the extraction of reagents, the syringe and needle need to be treated with inert gas without oxygen, so as to avoid potential safety hazard or decrease of effective content of reagents The device is used to replace the air in the syringe After exhausting the air from the syringe, insert it into a bottle filled with inert gas, slowly inhale the inert gas, and then empty it Repeat several times to ensure complete replacement In the process of extracting reagents, one hand should be used to fix the interface between the needle and the syringe, so as to prevent the extraction from slowly separating from the other hand After exhausting the air at the top, make the reagent reach the required volume Note that at this time, do not directly pull out the needle, but slowly lift the needle off the liquid surface, and extract some inert gas to avoid the reagent splashing from the needle during the transfer process Transfer the syringe quickly and insert it into the reaction bottle safely Note: in order to prevent the residual n-butyl lithium in the needle and needle tube from contacting with air and water vapor, which may cause danger or blockage, the syringe needs to be quenched with anhydrous tetrahydrofuran containing isopropanol before cleaning The following is the operation steps for taking and using a large amount of n-butyl lithium: a large amount of n-butyl lithium is taken through double row needles, the two ends of the double row needles are salt water and air release needles, the middle is connected with polytetrafluoroethylene tube, the needle head is kept on the liquid level, the needle head at one end is inserted into the bottle plug of the dropping funnel, and the other end is inserted into the bottle plug with butyl lithium The principle of using butyl lithium is to vacuumize through a water pump, suck butyl lithium into a drip funnel from a reagent bottle by means of a negative pressure, and connect the water pump to a tee in the reaction device connected with a nitrogen balloon When the tee is connected with the water pump, the long needle in the reagent bottle is inserted under the liquid surface, so that it is pumped into the drip funnel through the negative pressure butyl lithium When the liquid level is close to the required scale, pull the needle out of the reagent bottle, turn off the tee and disconnect it from the water pump, then the use of butyl lithium is completed PS: the screenshots of the above two cases are from the network video If there is any infringement, please contact the editor If you want to buy n-butyl lithium, shengbicheng n-butyl lithium reagent CAS No 109-72-8 is recommended.