HETEROACENE ANALOGUES: SYNTHESIS, GROUND-STATE GEOMETRY AND PHYSICAL PROPERTIES

Abstract

A series of heteroacenes are synthesized and well characterized as potential organic semiconductor materials. Detailed physical properties of these heteroacenes are studied, and they can be referred to as models of longer acenes. A pair of O-containing heteroacenes exhibit different ground states, molecular geometry and distinguishing physical properties with two oxygen atoms at the para- and meta- positions of the central benzenoid ring, respectivevly. Three N-containing heteroacenes are prepared as dications at their ground states, and can be regarded as isoelectronic structures of the corresponding all-carbon acenes. Among them, the pentacene-like radical cationic species is obtained and shows ambient stability. In addition, two diazaborole-ended heteroacenes are also synthesized and investigated. The pentacene derivative shows significantly enhanced stability with the maintenance of good aromatic character. Our research gives a new perception into the design and synthesis of stable and novel longer acene analogues in the future.