Dimer is a chemical structure that comprises two similar or identical monomers, which are also called subunits. These subunits are attached to each other courtesy a chemical bond. The bonding process is called dimerization. When the two monomers coming together are identical, the dimer is known as homodimer. In case the monomers are not the same, the dimer is referred to as heterodimer. Dimers can be found in several biological substances or molecules such as sugar, DNA, chemicals, and proteins.


The bond could be weak or strong or a covalent or non-covalent bond. A covalent bond entails sharing of electrons, whereas a non-covalent bond does not involve electron-sharing. A hydrogen bond is a non-covalent dimer. A diatomic gas is a covalent dimer. Carboxylic acid is a chemical compound that resorts to non-covalent or hydrogen bonding to make stable dimers. If the bonding process entails bringing together two identical subunits, the process is called homomeric. The process is called heteromeric if the bonding monomers are not identical.


Dimer acids or molecules that have an association with carboxylic acids are of use in industries. Made from fatty acids, these substances could be used in resins, adhesives, fuel oil, and lubricants. In medicine, dimers help diagnose thrombosis, a medical condition wherein a blood clot obstructs circulatory flow within a vein. These clots have the base of cross-linked protein fragments. These, when degraded, expose a structure called D-dimer. Increased D-dimer levels signify clot formation, which means susceptibility to thrombosis (blood clot process).