2021

Probing hyperconjugative aromaticity in 2H-pyrrolium and cyclopentadiene containing Group 9 transition metal substituent: Bridged carbonyl ligands can enhance aromaticity

Aromaticity and hyperconjugation are two fundamental concepts in organic chemistry. By combination of the two concepts together, the resulting hyperconjugative aromaticity has attracted considerable attention from both theoretical and computational chemists. However, previous studies are mainly focused on the main group chemistry. For the hyperconjugative aromaticity in the transition metal chemistry, the studies are limited to groups 10 and 11.

Rational design of the nickel‐borane complex for efficient hydrogenation of styrene

The Ni‐B complex 1BCF with a facilely accessible monophosphine (PtBu3) unit was theoretically designed, which was found to be more active than that with an ambiphilic ligand for hydrogenation of styrene. Substituting PtBu3 with a stronger electron donating ligand N‐heterocyclic carbene largely improves the activity of the Ni‐B complex.

https://onlinelibrary.wiley.com/doi/10.1002/jcc.26480

Aromaticity Survival in Hydrofullerenes: The Case of C66H4 with its π‐Aromatic Circuits

The isolated‐pentagon rule (IPR) is a determining structural feature accounting for hollow fullerene stabilization and properties related to Cn (n ≥ 60) cages. The recent characterization of an unprecedented non‐IPR hydrofullerene, C2v‐C66H4, bearing two heptagons with adjacent fused‐pentagons motif, largely dismiss this feature. Herein, employing DFT calculations, we explore the 13C‐NMR pattern and aromatic behavior of C2v‐C66H4.