Increased Antiaromaticity through Pentalene Connection in [<i>n</i>]Cyclo-1,5-dibenzopentalenes
Jan S. Wössner, Julia Kohn, Daniel Wassy, Mathias Hermann, Stefan Grimme, Birgit Esser
Abstract
Conjugated nanohoops incorporating nonalternant hydrocarbons have altered optoelectronic properties compared to [n]cycloparaphenylenes or other purely aromatic hoops. We synthesized [n]cyclo-1,5-dibenzopentalenes (n = 4, 5), in which nonalternant dibenzo[a,e]pentalenes are connected through their pentalene units. This leads to an increase in antiaromatic character and low-lying LUMO energies. Calculations show puckered or entangled conformations of the precursor macrocyclic Pt-complexes. Our study proves dibenzopentalene as a versatile nonalternant building block for conjugated nanohoops with modifiable antiaromaticity and optoelectronic properties.
Topics & Concepts
AntiaromaticityPentaleneChemistryConjugated systemBlock (permutation group theory)HOMO/LUMOConnection (principal bundle)AromaticityStereochemistryCrystallographyMoleculeOrganic chemistryPolymerCombinatoricsMathematicsStructural engineeringEngineeringSynthesis and Properties of Aromatic CompoundsMolecular Junctions and NanostructuresOrganic Electronics and Photovoltaics