Friedel-Crafts Acylation of Ferrocene - an Inquisitive Lab Demonstration
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- čas přidán 29. 03. 2020
- An inquisitive lab demonstration of the acylation of ferrocene. The product mixture is analyzed by TLC, the product is purified by column chromatography, and three colored compounds are isolated (acetylferrocene, diacetylferrocene, and unreacted ferrocene). WHY IS THERE NO AUDIO? Click "show more" for an explanation on an instructor might use this video. The video is embedded with over 30 questions to prompt inquiry and discussion. Complete list of questions: www.cpp.edu/~lsstarkey/ocheml... See the entire playlist at the @ChemistryConnected channel.
Without audio, instructors can use this video in a number of different ways. A student can watch it and record observations, like they would in a normal lab. In a typical lab, no one would be explaining the procedure to them as they go along. Other than using their hands and physically being in the lab, the expectations for completing a pre-lab assignment, keeping a lab notebook and submitting a lab report can be the same as usual. If desired by the instructor, answers to the embedded questions can be included in the observations, or as a separate report. Otherwise, they can simply serve as a reminder of the decisions that need to be made throughout out the procedure, and questions of this nature can be included in a separate assessment (e.g., lab final). Another option is to watch this video synchronously with your students, via videoconferencing. The video can be paused at each question to give time for a poll and a discussion. (As anyone who has used clickers in their lecture knows, the poll results can be very surprising!) This approach enables the sort of one-on-one mentoring an instructor can provide to their research students, or if they had unlimited time (and maybe access to a dozen clones of themselves) in a traditional lab setting. Viewing the video with your students provides an opportunity for students to ask questions and clear up those persistent misconceptions. With this approach, formative feedback is provided, and comprehension/retention can be probed at a later time with some form of assessment. Please use the comments section if you have other ideas!
ANSWER at 0:46.............My guess is the H3PO4 protonates the carbonyl oxygen on the acid anhydride and forms an oxonium ion which is resonance stabilized between ALL THREE oxygens which really activates the carbonyl carbon. Also the alkoxy group on the benzene is an EDG so it will activate the ring making the benzene ring even more nucleophilic and will attack the activated carbonyl carbon on the acid anhydride doing an acyl transfer and forming the product
QUESTION.........Why are you using gentle heat?????????? For alkylation i thought it was always done in the cold. Are you heating cause your are doing an acylation instead of an alkylation??????? Or are you heating because you are not using the best catalyst and electrophile?????????? Cause i know ethanoyl chloride would be more reactive than an anhydride for acyl transfer or really for any reaction probably. Should all friedel crafts ACYLATIONS be done with some heat instead of cold???????????
Great video !
Very informative video maam. Do the bubbles form due to release of CO2 from the Bi-Carbonate?
Sounds good! Check out this cool demonstration that provides evidence of CO2: czcams.com/video/eoEQFl32E7k/video.html
ANSWER at 1:00 ..........The 3rd molecule would be the major product. The FIRST carbonyl attached to the benzene ring is a EWG and will deactivate the ring. So the 2nd acylation will be on the other benzene ring. ALSO because the carbonyl is EWG it is a meta director. And in example molecules 1 and 2 the groups are added ortho and para
Very nice and educational video! I would have loved to also hear some audio though.
No audio, right?
Your speakers are not broken! Your question is a good one, though, so let me explain my choice. Without audio, instructors can use this video in a number of different ways. A student can watch it and record observations, like they would in a normal lab. In a typical lab, no one would be explaining the procedure to them as they go along. Other than using their hands and physically being in the lab, the expectations for completing a pre-lab assignment, keeping a lab notebook and submitting a lab report can be the same as usual. If desired by the instructor, answers to the embedded questions can be included in the observations, or as a separate report. Otherwise, they can simply serve as a reminder of the decisions that need to be made throughout out the procedure, and questions of this nature can be included in a separate assessment (e.g., lab final). Another option is to watch this video synchronously with your students, via videoconferencing. The video can be paused at each question to give time for a poll and a discussion. (As anyone who has used clickers in their lecture knows, the poll results can be very surprising!) This approach enables the sort of one-on-one mentoring an instructor can provide to their research students, or if they had unlimited time (and maybe access to a dozen clones of themselves) in a traditional lab setting. Viewing the video with your students provides an opportunity for students to ask questions and clear up those persistent misconceptions. With this approach, formative feedback is provided, and comprehension/retention can be probed at a later time with some form of assessment.
That’s what I was thinking, though without the pedagogical detail. 🤓