submolecular

Submolecular is an adjective used in chemistry, physics, and nanoscience to describe phenomena, analysis, or manipulations that occur at scales smaller than a whole molecule. It encompasses the analysis and control of internal molecular features such as atoms, chemical bonds, bond orders, functional groups, and subunits within larger molecular architectures or supramolecular assemblies. In contrast to macromolecular or supramolecular scales, submolecular studies probe the distribution of electron density, vibrational modes within a molecule, or the behavior of individual bonds.

Applications of submolecular inquiry include high-resolution imaging and spectroscopy that resolve intra-molecular structure, such as submolecular imaging by scanning tunneling microscopy, as well as computational methods that partition a molecule into submolecular fragments for energy decomposition or bond-level analysis. Submolecular control is reported in fields like molecular electronics and chemistry, where researchers aim to influence the properties of a molecule by modifying specific bonds or subunits, or by manipulating electron density distribution within a conjugated system. It also informs the study of reaction mechanisms at the bond level, where bond formation and cleavage occur within a single molecule.

Submolecular is a descriptive term rather than a formal scientific category; its precise usage varies by field and context. It is commonly used when discussing higher-resolution analyses or when researchers focus on the internal segments of molecules rather than the molecule as a whole.