CHEM10006 Lecture Notes - Lecture 15: Substituent, Newman Projection, Sigma Bond

• School: University of Melbourne
• Department: Chemistry
• Course: CHEM10006
• Professor: Frances Separovic

Document Summary

Compounds with the same molecular formula but different structural formulas or different spatial arrangements. Same molecular formula, atom-to-atom links, and bonding distances. There is free rotation about a sigma bond. An infinite array of conformations is possible through rotation. A conformer is one specific conformation of a molecule. Best determined by using a newman projection (looking directly down a c-c bond, can therefore show rotations. Staggered conformations are more stable than eclipsed conformations due to reduced steric interactions. The most stable conformations have the two methyl groups lying as far apart from each other as possible with a dihedral angle of 180 degrees. The most unstable conformation has the substituent groups lined up these are eclipsed. In between is the gauche conformation, where the methyl groups are next to each other but still are an equal distance apart. Note: a conformer is one specific conformation of a molecule.