Electron Density and Conformations

[cara_Budzinski_3D]

What role does electron density play in conformations? I know that the space filling model better shows electron density than other models, such as the ball and stick model, but what advantage does that have? Does changing conformation affect electron density?

[Lucy Nakashima 1E]

Electron density plays a role in the stability of molecules. If there is high electron-electron repulsion between adjacent atoms, then there will be greater steric strain and the molecule will be less stable than its conformation that reduces this strain. Because some conformations are so unstable, they are unlikely to be seen in that state in nature, and will favor a lower energy, more stable conformation. You should be able to determine what conformations are possible given a certain molecule, and then be able to determine which is more stable based on the potential angle, torsional, and steric strains.