Magnetically Induced Ring-Current Strengths in Möbius Twisted Annulenes

Area of Science:

• Computational Chemistry
• Organic Chemistry
• Theoretical Chemistry

Background:

• Molecular topology, characterized by linking number, influences molecular properties.
• Linking number is a sum of twist (local) and writhe (global) contributions.
• Aromaticity in twisted systems is an area of ongoing research.

Purpose of the Study:

• To investigate the relationship between topology and aromaticity in twisted cyclic annulenes.
• To explore how the partitioning of linking number into twist and writhe affects aromatic character.
• To study Möbius twisted annulenes and their dications.

Main Methods:

• Systematic investigation of cyclic all-trans C40H40 annulenes with varying twist numbers.
• Calculation of ring-current strength susceptibilities using the gauge-including magnetically induced currents (GIMIC) method.
• Analysis of Möbius twisted molecules and their dications.

Main Results:

• Aromatic properties are dependent on the linking number.
• Aromatic properties are also strongly dependent on the specific contributions of twist and writhe to the linking number.
• This contrasts with previous suggestions that only the linking number is the determining factor.

Conclusions:

• The interplay between twist and writhe is crucial for determining the aromaticity of Möbius twisted molecules.
• Findings provide a more nuanced understanding of structure-property relationships in complex molecular topologies.
• This research opens new avenues for designing molecules with specific electronic and aromatic characteristics.