Atypical 4 : 1 Charge-Transfer Complex of 2,7-Dinitro-9,10-Phenanthrenequinone with 9-Methyl-9H-Carbazole. Crystal and Molecular Structure, Quantum-Chemical Simulations

The crystal and molecular structure of the complex of 2,7-dinitro-9,10-phenanthrenequinone with 9-methyl-9H-carbazole (4C14H6N2O6⋅C13H11N) was determined by X-ray diffraction analysis. In the crystal of the complex, the donor molecule and two of the four crystallographically independent acceptor molecules form mixed-type stacks {–D–A $$_{1}^{{}}{{'}}$$ –A1–D'–A $$_{3}^{{}}{{'}}$$ –A3–D–A $$_{1}^{{}}{{'}}$$ –A1–D'–}∞. The other two acceptor molecules form parallel rows {–A2–A4–A2–A4–}∞ || {–A $$_{4}^{{}}{{'}}$$ –A $$_{2}^{{}}{{'}}$$ –A $$_{4}^{{}}{{'}}$$ –A $$_{2}^{{}}{{'}}$$ }∞ running along the stacks. The structures and properties of a number of model charge-transfer complexes of 2,7-dinitro-9,10-phenanthrenequinone with 9-methyl-9H-carbazole were investigated by quantum-chemical calculations at the density functional theory level. The energies of complex formation, the average distances between the donor and acceptor planes, and the charge transfer values from the donor to the acceptor were calculated.