A point I have been trying to emphasize to everyone this quarter is to think like a chemist. The tough part about chemistry is that in order to excel at it you need excellent critical thinking and problem solving skills. If you have these skills you will not only be able to use them in this class, but also all of your other classes and you future job(s). The rest of this unit in transition metal chemistry will focus on developing your critical thinking skills.
Our eyes are a complex instrument and are able to detect color in the wavelength range of 400 - 700 nm. In reality, this is just a tiny portion of the electromagnetic spectrum, and we can analyze all the other forms of radiation using advanced scientific instrumentation. The instrument we will focus on in this class is the UV-Vis spectrometer, which can detect radiation in the visible and ultra-violet regions in the spectrum. We can then use this information to analyze the electronic structure of molecules and complex ions. And by electronic structure, I mean how the electrons fill their orbitals, and how much energy it takes to excite electrons from orbital to orbital.
In order to interpret UV-Vis spectra properly and analyze electronic excitations between molecular orbitals, we first need to identify thehttp://www.blogger.com/img/blank.gif interactions between orbitals, or how the orbitals overlap. Therefore it is VITAL to know the shapes of the orbitals (in 3-dimensions with phases) and how they are derived. The tutorial shown here will help you do this.
When molecules form they will do anything they can to get all their electrons in the lowest energy possible. To determine the energy, we must analyze the interactions the central atom has with all of its ligands as a unit.
The stronger a bond is, the more stable it is. This lowers the overall energy.
The greater the orbital overlap, the stronger the bond, and the more stable the bonding molecular orbitals become. For a tutorial and overview and a review of what was taught in general chemistry covering molecular orbital theory check this site.
We will be using the topics in those tutorials and taking them one step farther by analyzing the d orbitals in this class. I posted a handout on carmen discussing molecular orbitals, bonding, MO diagrams, and color. Be sure to read through it. It will greatly help your understanding of the content. I discussed the molecular orbital diagrams of H2, O2, and an octahedral complex with Cr has the TM center with six oxygen ligands. We will pick up with this content on Monday in lecture.
Be sure to read over the transition metal lab sometime this weekend. I am hoping that it will tie all the concepts we discussed together and you will gain a better understanding of the material. Be sure to try to visualize the 3-Dimensional structures in this lab.
Inspirational Quote:
"It takes less time to do things right than to explain why you did it wrong."
Henry Wadsworth Longfellow
Songs Played Before Class:
Wiz Khalifa - Black And Yellow
Bruce Springsteen - Born To Run
Go Bucks! Beat the Badgers!
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