Revisiting the carbonyl n → π* electronic excitation through topological eyes: expanding, enriching and enhancing the chemical language using electron number distribution functions and domain averaged Fermi holes

摘要: The theory of chemical bonding is underdeveloped in electronic excited states, even small molecules. Fortunately, real space tools may be used to offer rich images simple excitation processes, as shown this work. statistics electron populations, through a fruitful combination distribution functions (EDFs) and domain averaged Fermi holes (DAFHs), was enlighten our knowledge paradigmatic process: the n → π* formaldehyde. Interestingly, results are perfectly compatible with an alternative perception transition: rotation one averaged-electron oxygen lone pair. This topological model does not require inter-orbital jumps explain final and, humble opinion, fact makes it, some extent, more realistic. Finally, other far-reaching conclusions emerge smoothly from analysis: (i) σ link contribute less total bond order (as measured by delocalization index) polar double than π one; (ii) populating antibonding orbital necessarily imply decreasing its corresponding bond.