Rubrene endoperoxide acetone monosolvate

Abstract

The title acetone solvate, C42H28O2·C3H6O [systematic name: 1,3,10,12-tetra­phenyl-19,20-dioxapenta­cyclo­[10.6.2.02,11.04,9.013,18]icosa-2(11),3,5,7,9,13,15,17-octa­ene acetone monosolvate], is a photooxygenation product of rubrene (systematic name: 5,6,11,12-tetra­phenyl­tetra­cene). The mol­ecule bends at the bridgehead atoms, which are linked by the O—O transannular bond, with a dihedral angle of 49.21 (6)° between the benzene ring and the naphthalene ring system of the tetra­cene unit. In the crystal, the rubrene mol­ecules are linked by C—H⋯O hydrogen bonds into a column along the c axis. The acetone solvent mol­ecules form a dimer around a crystallographic inversion centre through a carbon­yl–carbonyl dipolar inter­action. A C—H⋯O hydrogen bond between the rubrene and acetone mol­ecules is also observed.

Electron Density Analysis of the “O–O” Charge-Shift Bonding in Rubrene Endoperoxide

“…It is well-known that rubrene reacts with oxygen and forms a peroxide when a solution of it containing dissolved oxygen is exposed to visible light. − The resulting colorless rubrene endoperoxide (C 42 H 28 O 2 ) is stable in solution; however, its solid state properties have never been studied due to instability in air above 160 °C . A crystal structure of the compound was published recently as a cocrystal of rubrene endoperoxide with acetone as well as with dioxane and anisole, but it has not yet been studied with p -xylene. Interestingly, solvatomorphs of rubrene endoperoxide with acetone, anisole and p -xylene are isostructural and crystallize in the space group P 2 1 / c , whereas it crystallizes in P-1 with dioxane.…”