Probing the Influence\nof Alkyne Substitution on the\nElectronic and Magnetic Properties of Diindeno[1,2‑<i>b</i>;1′,2′‑<i>i</i>]anthracenes

To further the ability to manipulate the properties of\nopen-shell\nmolecules, logical and incremental modifications to molecular structure\nare key steps that provide fine-tuning of established diradicaloid\nscaffolds. We report the synthesis of an electronically “pure”\ndiradicaloid based on a 2,6-anthroquinoidal core where the once necessary\nethynyl “wings” are removed. Through the simplification\nof the overall electronic structure, the singlet–triplet energy\ngap increases by 0.3–0.4 kcal mol<sup>–1</sup> in the\nreported diradicaloids while avoiding significant disruption to their\noptoelectronic properties.