Tetra‐<i>tert</i>‐butyl‐<i>s‐</i>indacene is a Bond‐Localized <i>C</i><sub>2h</sub> Structure and a Challenge for Computational Chemistry
Lucas J. Karas, Said Jalife, Renan V. Viesser, João Vitor Soares, Michael M. Haley, Judy I. Wu
Abstract
Abstract Whether tetra‐ tert ‐butyl‐ s ‐indacene is a symmetric D 2h structure or a bond‐alternating C 2h structure remains a standing puzzle. Close agreement between experimental and computed proton chemical shifts based on minima structures optimized at the M06‐2X, ωB97X‐D, and M11 levels confirm a bond‐localized C 2h symmetry, which is consistent with the expected strong antiaromaticity of T t B‐ s ‐indacene.
Topics & Concepts
ChemistryAntiaromaticityTetraSymmetry (geometry)ProtonChemical bondMaxima and minimaComputational chemistryCrystallographyMoleculePhysicsAromaticityQuantum mechanicsOrganic chemistryGeometryMedicinal chemistryMathematicsMathematical analysisMolecular spectroscopy and chiralityOrganic Chemistry Cycloaddition ReactionsAdvanced Chemical Physics Studies