Non-covalent or supramolecular interaction refers to a variety of interactions that are not covalent in nature, but are strong enough to provide the attractive force between molecules or parts of molecules so as to hold them together, usually in a specific orientation or conformation. These non-covalent interactions include coordination bonds, dipole-dipole interactions, hydrogen bonds, pi − pi stacking or van der Waals interactions. A comparative overview of these different types of non-covalent interactions is as presented.  These bonds are weak by nature and must therefore work together to have a significant effect. In addition, the combined bond strength is greater than the sum of the individual bonds. This is because the free energy of multiple bonds between two molecules is greater than the sum of the enthalpies of each bond due to entropy effects.      Hydrogen bonding Hydrogen bonding is one of the most significant interactions among the weak

Crystal Field Splitting (CFS) patterns for various ligand fields Crystal Field Splitting diagrams for some common fields referred to a common barycentre. Splittings are given with respect to Delta (octahedral). [Reference: Catherine Housecroft]