konformationell

Konformationell is an adjective used in chemistry, primarily in German-language texts, to describe something related to a molecule’s conformation—the spatial arrangement of atoms that can change by rotation about single (sigma) bonds without breaking any bonds. The corresponding English term is conformational, and the noun form is conformer.

In contrast to configurational isomers, which require bond breaking to interconvert, konformationelle interconversions occur through rotation around sigma bonds. This makes conformations often interconvertible on relatively fast timescales at room temperature for many molecules, leading to conformational ensembles rather than a single fixed structure. The energy differences between conformers determine their relative populations and reactivity.

Common examples include the rotation around the carbon–carbon bond in ethane, which gives staggered and eclipsed conformers, and the multiple conformations of cyclohexane, which interconvert between chair and boat forms (with chair being the most stable). In larger molecules, conformational flexibility can influence binding in chemical reactions, catalysis, and material properties.

In biology, konformationell related concepts describe how macromolecules such as proteins and nucleic acids adopt alternative shapes. Conformational changes can activate or inhibit function, drive enzymatic mechanisms, and underlie processes like folding and allostery. The study of konformationell properties combines experimental methods (NMR, X-ray crystallography, cryo-EM) with computational approaches (molecular mechanics, quantum chemistry, molecular dynamics) to map energy landscapes and predict behavior under different conditions.

Overall, konformationell describes the dynamic, rotation-accessible arrangements of a molecule’s atoms and their implications for chemistry and biology.