Two new cases of polymorphism in diagonally substituted rubrene derivatives

Acta Crystallogr E Crystallogr Commun. 2023 Mar 31;79(Pt 4):406-409. doi: 10.1107/S2056989023002736. eCollection 2023 Mar 1.

Abstract

The crystal structures of two rubrene derivatives, 5,11-diphenyl-6,12-bis-[4-(tri-fluoro-meth-yl)phen-yl]tetra-cene, C44H26F6, and 5,11-bis-(4-tert-butyl-phen-yl)-6,12-di-phenyl-tetra-cene, C50H44, are presented. Each are substituted on diagonal (5/11) phenyl rings. Each derivative has one polymorph reported previously. A discussion of the differences between each derivative and its previously reported polymorph is provided. The triclinic packing of the CF3-substituted structure is similar to the packing of the parent rubrene's triclinic polymorph. In the tert-butyl-substituted structure, a planar tetra-cene core formed, which has been hypothesized but never published. Crystallization conditions are provided as they differ from previous reports.

Keywords: crystal structure; polymorphism; rubrene.

Grants and funding

Funding for this research was provided by: National Science Foundation (grant No. CHE-1229400).