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The Pi Molecular Orbitals of Cyclobutadiene

The Pi Molecular Orbitals of Cyclobutadiene

May 10, 2017

Previously, we’ve seen what the molecular orbitals of benzene look like, and that the fact that they are partially duplexed (or to use the proper nomenclature, “degenerate“) helps to explain benzene…

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The Pi Molecular Orbitals of Benzene

The Pi Molecular Orbitals of Benzene

May 5, 2017

Today, let’s go through how to draw out the molecular orbitals of benzene. We’ll compare them with the molecular orbitals for (linear) hexatriene. The big takeaway is that from contrasting the molecular o…

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Pi Molecular Orbitals of Butadiene

February 28, 2017

In the last post in this series we built up the pi molecular orbitals of the allyl pi-system, consisting of three consecutive p orbitals in conjugation. We saw that: The number of molecular orbitals (n) for a pi-syst…

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Molecular Orbitals of The Allyl Cation, Allyl Radical, and Allyl Anion

Molecular Orbitals of The Allyl Cation, Allyl Radical, and Allyl Anion

February 16, 2017

In the last post, we showed how to build a molecular orbital (MO) diagram for a typical C-C pi bond. We saw that: The number of molecular orbitals equalled the number of contributing atomic orbitals. The overlap of …

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Molecular Orbital Diagram For A Simple Pi Bond – Bonding And Antibonding

Molecular Orbital Diagram For A Simple Pi Bond – Bonding And Antibonding

February 14, 2017

In the previous post in this series, “On Conjugation and Resonance“, I warned that in order to gain a deeper understanding of some of the concepts ahead, we’re going to need to go into MO theory. Bu…

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UV-Vis Spectroscopy: Absorbance of Carbonyls

UV-Vis Spectroscopy: Absorbance of Carbonyls

September 26, 2016

In our last post we showed that molecules with C-C pi (π) bonds absorb light in the UV-visible region, which promotes electrons from (bonding) π orbitals to (anti bonding) π* orbitals. We saw that the energy requ…

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Radical Reactions: Why Is “Light” Or “Heat” Required?

Radical Reactions: Why Is “Light” Or “Heat” Required?

August 30, 2013

If you come across just a few free-radical reactions, you should notice a familiar pattern. Every free-radical reaction that you’ll encounter is accompanied by either “heat” or “light”. I…

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