This News Item was adapted by students Lejla Mutapcic, Joshua Ninichuck, and Constance Jo Roebke as part of their Chemistry 212 Project in WS00 under the gui dance of Prof. Rainer Glaser.

Glaser's "Chemistry is in the News"
To Accompany Wade Organic Chemistry 4/e.
Chapter 26. Synthetic Polymers.


For each of the following questions, please refer to the following article:
Vivid Colors in the Palm of Your Hand


Editorial Comments

The ability to surf the Internet with a cellular phone is not completely new, but to be able to watch television is quite a novelty. To see it in color would be very exciting indeed!

Polymers are incredibly large and complex molecules. Take a look at th e website for Cambridge Display Technology. Click on the link "What are LEP's?" Here you will observe the structure of one of the company's light emitting organic molecules. The pi-bond conjugati on allows electrons to flow throughout the length of the molecule.

Let's take a closer look at light emitting polymers. What a complex compound to use to simply "paint on" lights. T he truth is, it is a little more complicated than that. Look at the tutorial on the function of light emitting diodes.

There are numerous proposed functions for this new technology. There are also many proposed benefits to the use of polymer technology over the status quo. Take a look at how polymers m ay be effecting your life in the future.

Pertinent References
Chapter 26
Chapter 1. Section 3. Bond Formation: The Octet Rule.
Chapter 1. Section 9. Resonance.

Questions

< P>Question 1:What is a Light Emitting Diode?

Answer 1:A light-emitting diode is a p-n junction that emits light when forward-biased: one side of the diode is a semiconductor of type p (majority carrier s are holes) the other side is of type n (majority carriers are electrons)

Question 2: Suggest two atoms to use when making organic molecules into diodes (hint: see the tutorial on light emitting diodes).

Answer 2: Lithium and Nitrogen
Question 3: Draw the resonance structures for the oraganic light emitting molecule discussed, showing conjugation of the bonds

Answer 3: Point the cursor to the link "Double and Triple bonds" on the web page, and the lewis structure will a ppear. Simply "push" the electrons back and forth to get resonance structures.

Question 4:What are the advantages of OLEDs over black lit LCD displays?

Answer 4:When OLEDs are used as pixels in flat panel displays they have some advant ages over back lit active-matrix LCD displays - greater viewing angle, lighter weight, and quicker response. Since only the part of the display that is actually lit up consumes power, the most efficient OLEDs available today use less power.

Quest ion 5: This technology will increase accessibility of television and other forms of media. Considering the controversy surrounding the influence of the entertainment industry on young people, will pocket size television sets be an asset to our society?

Answer 5: Answers will vary.