Monthly Archives: February 2015
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
Posted in Homework, Molecular modeling
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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:
Posted in Molecular modeling
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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
Posted in Molecular modeling
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Diffusion-controlled rate constants are the MAX
Today’s class presented two formalisms that organic chemists use for connecting rates, rate constants, and the shapes of PE surfaces: Arrhenius equation (old-school but still useful and still widely used; go here for more background on collisions & kinetics) transition … finish reading Diffusion-controlled rate constants are the MAX
Posted in Uncategorized
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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
Posted in Molecular modeling, Papers for discussion
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