
Molecular Conformation |
The subatomic measurement technique called nuclear magnetic resonance spectroscopy (NMR) is employed to ascertain physical conformation of molecules. From this technique, distance, angle, and dihedral angle data is obtained. Dihedral angles arise consequent to a phenomenon where atom subsets are physically constrained to Euclidean planes. "In the rigid covalent geometry approximation, the bond lengths and angles are treated as completely fixed, so that a given spatial structure can be described very compactly indeed by a list of torsion angles alone... These are the dihedral angles between the planes spanned by the two consecutive triples in a chain of four covalently bonded atoms." Crippen & Havel recommend working exclusively with distance data because they consider angle data to be mathematically cumbersome. The present example shows instead how inclusion of dihedral angle data into a problem statement can be made elegant and convex. |