Chemical oxidation of a perylene and coronene mixture with GaCl,results in the formation of a unique mixed polycyclic aromatic hydrocarbon(PAH)product of the composi-tion,[(C_(20)H_(2))_(2)(C_(24)H_(12))]^(2+)(GaCl_(4...Chemical oxidation of a perylene and coronene mixture with GaCl,results in the formation of a unique mixed polycyclic aromatic hydrocarbon(PAH)product of the composi-tion,[(C_(20)H_(2))_(2)(C_(24)H_(12))]^(2+)(GaCl_(4)^(-))_(2)·(C_(6)H_(6))_(2),as revealed by single crystal X-ray diffraction.The crystal structure exhibits t-stacked columns of repeating perylene-perylene-coronene units,withπ-stacks separated by GaCI4-anions and benzene molecules.Interplanar contacts in the asymmetric PAH trimer average 3.352(2)Å,with an atom-over-atom t-surface overlap between neighboring perylene and coronene.In the solid-state,multiple H…Cl contacts between the perylene moieties and GaCl_(4)^(-)anions are present,with additional C-H…πcontacts found between coronene and benzene molecules.The EPR spectrum of the crystals shows a strong singlet with a g-factor of 2.0041,indicative of an organic radical persistent in a very broad temperature range.The UV-vis absorption spectra point to the asymmetric charge distribution in the mixed PAH trimer,in accord with core deformation revealed crystallographically.The original crystal structure is used as a model for in-depth theoretical description of bonding and charge assignment within a heteromolecular PAH trimer.Computational studies reveal that the surrounding GaCl_(4)^(-)and benzene units play a crucial role in stabilizing the structure and modulating the electronic properties of the perylene-perylene-coronene stacks.Computational results also fuly support the interpretation of the uneven charge distribution based on solid-state characteristics and spectroscopic data.展开更多
基金Financial support from the U.S.National Science Foundation for this research to M.A.P.(CHE-2404031)to M.K.(CHE-2107820)is gratefully acknowledged.
文摘Chemical oxidation of a perylene and coronene mixture with GaCl,results in the formation of a unique mixed polycyclic aromatic hydrocarbon(PAH)product of the composi-tion,[(C_(20)H_(2))_(2)(C_(24)H_(12))]^(2+)(GaCl_(4)^(-))_(2)·(C_(6)H_(6))_(2),as revealed by single crystal X-ray diffraction.The crystal structure exhibits t-stacked columns of repeating perylene-perylene-coronene units,withπ-stacks separated by GaCI4-anions and benzene molecules.Interplanar contacts in the asymmetric PAH trimer average 3.352(2)Å,with an atom-over-atom t-surface overlap between neighboring perylene and coronene.In the solid-state,multiple H…Cl contacts between the perylene moieties and GaCl_(4)^(-)anions are present,with additional C-H…πcontacts found between coronene and benzene molecules.The EPR spectrum of the crystals shows a strong singlet with a g-factor of 2.0041,indicative of an organic radical persistent in a very broad temperature range.The UV-vis absorption spectra point to the asymmetric charge distribution in the mixed PAH trimer,in accord with core deformation revealed crystallographically.The original crystal structure is used as a model for in-depth theoretical description of bonding and charge assignment within a heteromolecular PAH trimer.Computational studies reveal that the surrounding GaCl_(4)^(-)and benzene units play a crucial role in stabilizing the structure and modulating the electronic properties of the perylene-perylene-coronene stacks.Computational results also fuly support the interpretation of the uneven charge distribution based on solid-state characteristics and spectroscopic data.
