Overview
Halogens are ortho–para directors. They are more electronegative than carbon. Therefore, as ring substituents, they can withdraw electrons through the inductive effect and deactivate the aromatic ring towards electrophilic substitution. Halogens also have an electron-donating resonance effect on the ring, which influences the orientation of the incoming electrophile. If an electrophile attacks at the ortho or the para position, the halogen donateslectrons and stabilizes the intermediate through the halonium ion. The resonance forms arising from the meta attack do not generate the halonium ion. Subsequently, the energies of ortho and para forms are lower, and these form faster. In summary, a weaker electron-donating resonance effect of the halogens makes them ortho–para directors, and a more substantial electron-withdrawing inductive effect makes them deactivators.…
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An embed code allows you to place a JoVE video directly inside of your learning or training environment. Most learning management systems such as Canvas, Blackboard, and Moodle require an embed code for JoVE content to stream.
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How to embed a video
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STEP 2: PASTE THE EMBED CODE INTO YOUR ENVIRONMENT
Embed codes can be used in most learning management systems (Canvas, Blackboard, Moodle…), organizational websites, and a host of other tools. The specifics of how to add in an embed code will depend on your environment.
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