molekylaaristestien

Molekyylikristallit, or molecular crystals, are a type of crystalline solid where the constituent particles are neutral molecules. These molecules are held together in a crystal lattice by relatively weak intermolecular forces, such as van der Waals forces (including London dispersion forces and dipole-dipole interactions) and hydrogen bonds. The strength of these forces determines the physical properties of the molecular crystal.

Due to the weaker nature of intermolecular forces compared to the ionic or covalent bonds found in other crystal types, molecular crystals typically exhibit lower melting and boiling points. They are often soft, have low electrical conductivity, and can be poor thermal conductors. Many molecular solids are also insoluble in water but soluble in nonpolar organic solvents.

Examples of molecular crystals include ice (a hydrogen-bonded network of water molecules), sugar (sucrose), iodine, naphthalene, and dry ice (solid carbon dioxide). In ice, the strong hydrogen bonds create a rigid, open lattice structure. In contrast, crystals like iodine or naphthalene are held together primarily by weaker London dispersion forces. The arrangement and size of the molecules, as well as the specific intermolecular forces present, dictate the overall crystal structure and its macroscopic properties. Understanding the nature of these intermolecular interactions is key to predicting and explaining the behavior of molecular solids.