Insight into the Electronic State of 1-Phenylthieno [2,3-d]borepin by Means of Nuclear Magnetic Resonance Spectroscopy

In order to obtain an insight into the electronic states in connection with the condensation modes of thiophene and borepin rings, we examined 1-phenylthieno[2,3-d]borepin (2). While 1-phenylthieno[3,4-d]borepin is a peripherally conjugated compound, 2 was shown to be an aromatic compound which maintains characteristics in conjugation of individual rings.