Comment on “Exploiting electronic strategies to stabilize a planar tetracoordinate carbon in cyclic aromatic hydrocarbons” by O. Yañez et al., Chem. Commun., 2017, 53, 12112

Abstract

Unequivocally, the global minimum geometry for C₇H₂ is the linear triplet ground electronic state of heptatriynylidene (1). However, the entitled article reports that the global minimum geometry for C₇H₂ is the singlet ground electronic state of 1-(buta-1,3-diynyl)cyclopropenylidene (2). We disagree with this result.