Online Lab Submission
Students: Instructors: Pre-Lab Assignments
Interactive Animations:

iTRQ - Organic Mechanisms

The ability to draw organic mechanisms can be attained and maintained through repeated practice. While this has traditionally been accomplished with un-timed homework problems, the proliferation of sites that provide solutions to homework problems has resulted in some students getting the correct answer without altering their long-term memory. In collaboration with Chem21Labs users, iTRQs (interactive TRQs) have been created where students perform a series of steps in a certain span of time (e.g. 50 - 200 seconds).

In the Organic Mechanism iTRQ, if students can correctly draw the mechanism before the timer reaches 0 seconds, they will have completed the assignment for full-credit. If they draw the mechanism but it takes longer than the time on the timer, they have 1 completed mechanism . . . . the parameters of the iTRQ may require the student to submit 5 completed mechanisms outside the time to complete the assignment AND earn full-credit.

Early in the Organic curriculum students are introduced to "curved arrows" and "pushing electrons" with static examples like . . . .

Chem21Labs has added interactivity and active learning to these static examples. In addition, this active learning interaction is an assignment that alters long-term memory and it can be repeatedly assigned to maintain this altered memory. Click / drag on the drawing palette to create the mechanisms shown above.
The mechanism iTRQs work on touch-screen devices.

As a student progresses in Organic, they are expected to learn the mechanism of many of the 120 - 150 reactions. These mechanisms can be multi-step . . . . containing intermediates, formal charges and stereochemistry. An interactive approach that is assigned (and re-assigned) is an effective way to place (and maintain) this information in the student's long-term memory. The mechanism for Cyclohexene + Br2 is a great example . . . .

Steps for Drawing the Cyclohexene + Br2 Mechanism:

  1. Click the alkene double bond and drag the mechanism arrow to the closest Br atom . . . you will hear a "tada" sound.
  2. Click the bond between the two Bromine atoms and drag the mechanism arrow to the rightmost Br atom - you will hear a "tada" sound.
  3. Click a pair of electrons from the leftmost Br atom and drag the mechanism arrow to one of the alkene carbons - you will hear a "tada" sound.
  4. Now click on the correct intermediate.
  5. If you don't know the next mechanism step, wait 10 seconds and it will be displayed to you.
  6. Continue drawing mechanism arrows until the mechanism is complete

There are over 50 HTML5 mechanisms at this time with plans to create ~ 50 more of the most common Organic Chemistry mechanisms.