General Elution Procedure: Procedure Dissolve the residue from Experiment 3 with 0.5 mL ofCl-izClz (the amount is not important, use about 1/2 a Pastuerpipette full) within the roundbottomed ﬂask. Weigh out 0.3 g of silica gel (70-230 mesh) on the top-loading balances and add this to the CHzClz solution of thereaction residue in the round-bottomed ﬂask. Evaporate the solvent on the rotavap until a dry red—brownsilica powder remains. Now the mixture is adsorbed on thesurface of the silica.Add 7.0 cm of fresh,new silica gel (70-230mesh) to your chroma-tography column. Tapthe column on thebench lightly to makesure all the materialhas settled. Clamp the column tothe support in your 71cm ol sand hOOd’ l’lllX’llllF.‘ DI ill:Carefully add the prod-uct—adsorbed silica prepared above as alayer on top of the sili-ca contained in thecolumn. Carefully add ~1.0 cmof sand to the top ofthe column. Youshould now have a 7.0cm high, white layer of silica in the column, about ~1.0 cm ofa red-brown silica layer (your product mixture is adsorbedhere) topped by ~1.0 cm of sand. Clean out both of your round—bottomed ﬂasks (25 and 50-mL) and dry in the oven if necessary. Pre-weigh each ﬂask.Elute the column with 12—15 mL of hexanes. Make sure theseptum capping the bottom of the column is removed. Use abeaker to collect what is called fore-run, the solvent ﬁrst elut-ed from the column that does not contain one of the prod-ucts. 1. Make sure you have acollection container un-der the column andcarefully ﬁll the columnwith the eluting solvent.Be sure not to disturbthe sand layer while do—ing this. 2. Assemble the apparatusto pressurize the columnusing a dry piece of latextubing and a disposable ‘syringe. k 3. Pull back the syringe plunger and then push the otherend of the latex tubing over the top of the column care-fully. DO NOT DRAW BACK ON THE SYRINGEWHEN THE TUBING IS ATTACHED TO THE COL-UMN!!! 4. Slowly depress the syringe plunger. Allow the built uppressure to dissipate. 5. Remove the tubing from the end of the column and re-plenish the current eluting solvent. 6. Repeat steps 35 as necessary, changing the receivingcontainer and eluting solvent as needed. Part 1: Ferrocene Band Elution Using the General Elution Ferroce arid elufionProcedure described above, TR]elute the column with enough ”ﬂag… I”hexanes to fully collect the ‘2 -ﬁrst yellow colored band(ferrocene). For most stu-dents, this is typically 12-15mL. Use a beaker to collectwhat is called fore-run, thesolvent ﬁrst eluted from thecolumn that does not containone of the colored products.Use the ﬁrst of the two pre-weighed flasks to collect theyellow band.Make sure that the yellowband has completely movedoff the column. NEVER LETANY PART OF THE STA- TIONARY PHASE GO DRYAFTER THIS POINT. Ace‘vlferrocene band elutr’on .. .
Delivering a high-quality product at a reasonable price is not enough anymore.
That’s why we have developed 5 beneficial guarantees that will make your experience with our service enjoyable, easy, and safe.
You have to be 100% sure of the quality of your product to give a money-back guarantee. This describes us perfectly. Make sure that this guarantee is totally transparent.Read more
Each paper is composed from scratch, according to your instructions. It is then checked by our plagiarism-detection software. There is no gap where plagiarism could squeeze in.Read more
Thanks to our free revisions, there is no way for you to be unsatisfied. We will work on your paper until you are completely happy with the result.Read more
Your email is safe, as we store it according to international data protection rules. Your bank details are secure, as we use only reliable payment systems.Read more
By sending us your money, you buy the service we provide. Check out our terms and conditions if you prefer business talks to be laid out in official language.Read more