Mittekovalentne

Mittekovalentne is a descriptor used in chemistry to refer to bonds that show both ionic and covalent character. In such bonds, electrons are not fully transferred as in a purely ionic bond, nor are they shared exclusively as in a purely covalent bond. Instead, there is partial sharing of electron density between bonded atoms with a substantial electrostatic attraction between charged species. The balance between the two characters depends on factors such as electronegativity differences, ion polarizability, and the extent of orbital overlap.

Ionic character tends to dominate when electronegativity differences between the bonded atoms are large, while covalent character increases with greater orbital overlap and polarizability. Many real-world bonds lie along a spectrum between purely ionic and purely covalent, and are described as having partial or mixed covalent character. Examples include bonds in many metal–nonmetal compounds, transition metal oxides, and coordination complexes where ligand–metal bonds exhibit significant covalency due to d-orbital interactions. Even in compounds traditionally regarded as ionic, measurable covalent character can influence properties such as bond lengths, force constants, and reactivity.

Measurement and interpretation of mittekovalentne rely on multiple approaches. Experimental indicators include bond lengths and vibrational spectra that reflect covalent interactions, while estimates of ionic character can be drawn from electronegativity differences (Pauling scale) and methods like Fajans’ rules. Computational chemistry provides quantitative access through analyses of bond overlap populations, charge distribution, and entropy of mixing. Understanding mittekovalentne helps explain why some materials deviate from idealized ionic models and how bond character affects physical properties and reactivity.