The electron density of delocalized bonds (EDDB) applied for quantifying aromaticity

Area of Science:

• Computational chemistry
• Quantum chemistry
• Organic chemistry

Background:

• Aromaticity is a key concept in chemistry, influencing molecular stability and reactivity.
• Existing aromaticity descriptors often rely on structural, electronic, or magnetic properties.
• Quantifying electron delocalization remains a challenge in understanding aromaticity.

Purpose of the Study:

• To introduce and define a novel measure of aromaticity using electron density of delocalized bonds (EDDB).
• To investigate the interplay between bond-length alternation, electron delocalization, and ring current diatropicity.
• To compare the new EDDB index with established aromaticity descriptors.

Main Methods:

• Application of the electron density of delocalized bonds (EDDB) method.
• Correlation and principal component analyses of various aromaticity descriptors.
• Qualitative comparison of EDDB with magnetically induced ring-current density maps.
• Comparative study using the kekulean multicenter index (KMCI) and the proposed EDDB^k index.

Main Results:

• EDDB provides a new perspective on aromaticity in molecular rings.
• Established relationships between structural, electronic, and magnetic properties related to aromaticity are confirmed and refined.
• The EDDB index shows promise in describing cyclic electron delocalization in organic aromatics.

Conclusions:

• The electron density of delocalized bonds (EDDB) offers a valuable new tool for assessing molecular aromaticity.
• EDDB complements existing methods and provides insights into electron delocalization.
• Further research into EDDB^k is warranted for describing cyclic delocalization.