Mehrwertige

Mehrwertige is a German chemist’s term used to describe substances, atoms, or ions that can form more than one bond or possess multiple reactive sites. The word comes from mehr, meaning “more,” and wertig, related to valence, and corresponds to the English terms polyvalent or multivalent.

In inorganic and coordination chemistry, mehrwertig can refer to ions with higher oxidation states or to ligands with several donor sites. For example, trivalent cations such as Al3+ or Fe3+ are described as mehrwertig compared with monovalent ions. Likewise, ligands containing multiple donor atoms, such as ethylenediamine (two donor sites), are sometimes called mehrwertige Liganden because they can bind to a metal center at several positions, enabling chelation and extended coordination networks.

In polymer and organic chemistry, mehrwertige Monomere describe monomers that offer more than one reactive group. Such multifunctional monomers enable cross-linking, leading to three-dimensional polymer networks. Examples include glycerol, which has three hydroxyl groups, or glycidyl ethers with multiple reactive epoxide groups.

The term also appears in discussions of polyprotic or multiprotic acids, where mehrwertige Säuren can donate more than one proton. In modern usage, however, more common terms such as polyvalent, multivalent, polyfunctional, or multiprotic are often preferred to describe these concepts.

Overall, mehrwertige conveys the idea of multiple bonding opportunities or reactive sites within a single species, spanning inorganic, organic, and polymer contexts.