Comparative studies of the noncovalent interactions in the single‐crystal packing of pyrene, pyrene‐4,5‐dione, and pyrene‐4,5,9,10‐tetraone

Abstract

Pyrene-4,5-dione and pyrene-4,5,9,10-tetraone are K-region oxidized derivatives of pyrene, which show interesting structural and electronic properties as well as useful application in organic electronic and optoelectronic devices. The single-crystal structures of pyrene and pyrene-4,5-dione have been published, but the crystallographic data of pyrene-4,5,9,10-tetraone has not. In this work, the single-crystal structure of pyrene-4,5,9,10-tetraone has been clearly elucidated for the first time, and the detailed crystallographic properties were analyzed and discussed in comparison with those of pyrene and pyrene-4,5-dione. Various noncovalent interactions taking place within the supramolecular assemblies that exist in the crystal packing of these compounds were studied by Hirshfeld surface analysis and density functional theory (DFT) calculations. Our joint experimental and computational analyses provide fundamental understanding of the electron density properties, interaction energies, and frontier molecular orbital (FMO) properties for these pyrene systems and establish correlations of these properties with diverse supramolecular assembling motifs.

The Intermolecular Interactions of Pyrene and its Oxides in Vacuum and in Toluene Solution

“…The geometries and energies of the conformers that make up the ensemble for the pyrene homodimer in toluene solution are first described and discussed. To facilitate comparison and contrast, the ensemble for the pyrene dimer in the gas phase, which has been well-studied previously, 11,[26][27][28][29][30][31][32][33][34][35][36][37][38][39] is determined and discussed. Subsequent discussions focus on the ensembles in toluene solution for the pyrene-4,5-dione homodimer, the pyrene-4,5,9,10-tetraone homodimer, and the pyrene/pyrene-4,5,9,10-tetraone heterodimer.…”

“…For (pyrene-4,5,9,10-tetraone) 2 , reoptimization of the low-lying portion of the CREST ensemble yields seven conformers, see Figure 3. The 0G conformer (C i symmetry) best approximates the crystal structure, 26 but is not the lowest in energy. Due to the extra carbonyls in pyrene tetraone relative to pyrene dione, this conformer can be considered analogous to both 180G and 0G of pyrene-4,5-dione.…”

“…Previous studies of the (pyrene) 2 ensemble have been done in the gas phase. 11,[26][27][28][29][30][31][32][33][34][35][36][37][38][39] While the ensemble that exists in toluene solution is of primary interest, the gas phase energies are necessary to isolate the solvation energy, and are useful for comparison with previous results. Reoptimization of the solution-phase ensemble using ωB97X-D4/def2-TZVP (gas phase calculation) gives the gas-phase ensemble.…”

“…The dimerization of pyrene has been studied extensively by computation. 11,[26][27][28][29][30][31][32][33][34][35][36][37][38][39] Much of the published work uses force fields, paired with molecular dynamics or metadynamics. 27,33,34,40 Such work has mostly focused on kinetics or on (electronic) binding energies, without considering free energies.…”

“…26,28,29,32,37 Only one study used ab initio methods to determine a free energy of dimerization for pyrene. 26 This study, by Zreid et al, determined both the binding energy, and the free energy of dimerization for the dimers of pyrene, pyrene-4,5-dione, and pyrene-4,5,9,10-tetraone, using the nearest-neighbour structures extracted from the crystal structures. They computed both binding and Gibbs free energies using ωB97X-D/6-311++G(2d,p).…”