Category Archives: Molecular modeling
Setting up Spartan icons
I mentioned this topic briefly during a modeling session, but it went by fast and you may have missed the key instructions. The idea here is that Spartan lets you choose which icons to display in your Spartan window so … finish reading Setting up Spartan icons
Models for Sigmatropic Rearrangements & Migrations
The following models were optimized at EDF2/6-31G**. They include IR calculations (unscaled frequencies). [1,n] migrations 1,2-H in acyclic carbocation: TS | Rct 1,5-H in acyclic system: TS | Rct 1,5-H in cyclic system: TS | Rct 1,7-H in acyclic system: … finish reading Models for Sigmatropic Rearrangements & Migrations
Error: maximum number of optimization cycles was reached
Spartan can produce a number of “job failed” messages. The most frequent reason for failure is “maximum number of optimization cycles was reached.” I’ll explain what this message means, why it is so common, and what you can do about … finish reading Error: maximum number of optimization cycles was reached
Converting published models into Spartan models
Most papers that include molecular models publish the atomic coordinates and total energies in the supporting information. The list of coordinates can be easily downloaded, saved on your computer, and converted into a Spartan’14 model by following these steps:
Hard and Soft Lewis Acids
The authors of paper #2 reported on the behavior of a chiral dienophile in Diels-Alder reactions. For reasons that I will discuss on another day, they wanted to conduct their reactions at the lowest possible temperature and so a Lewis … finish reading Hard and Soft Lewis Acids
Anions that can tolerate 2-norbornyl cation
I forget whether this question came up in our discussion of the Scholz paper (paper #1), but 2-norbonyl cation was crystallized with Al2Br7 anion. The authors described this anion as “weakly coordinating,” Our interest in binding challenging ions such as … finish reading Anions that can tolerate 2-norbornyl cation