Partial charge

Under partial charge (lat. pars 'part', hence partial charge ), and partial charge, one understands the different charge of two binding partners (atoms or parts of molecules ). They occur through polar atomic bonds. The charges are identified in chemical Formal with δ - and δ above the element symbol.

Are there differences between the binding partners of an atomic bond in its electronegativity, so the distribution of bonding electrons is no longer uniform, but there is a polarization ( different charge of the partners ), which is caused by the displacement of the charge carriers ( electrons). This electron displacement causes the binding partner in part ( = partial) are positively and negatively charged. The partial charge within an XY bond can be estimated with the following formula:

Stands for the group number of the element, the number is not involved in the bonding electrons of the atom, the number of electrons which are involved in the binding and and the electronegativity of or. Are obtained for example for the HF molecule: and F is negative and thus partial partial H positively charged.

The greater the electronegativity difference ( ΔEN ), the greater is the degree of polarization and thus the formation of the partial charges. As between different charges bonding forces arise, these will be greater, the greater the charge difference is. From a certain magnitude of the difference is referred to as ion binding and ion.