CHARGE TRANSFER COMPLEXES OF NITRO DERIVATIVES OF 9,10-PHENANTHRENEQUINONE WITH ANTHRACENE. CRYSTAL AND MOLECULAR STRUCTURES OF THE (1:1) COMPLEX OF 2,4,7-TRINITRO- 9,10-PHENANTHRENEQUINONE WITH ANTHRACENE

Abstract: Charge transfer complexes (CTCs) are obtained by the interaction of 9,10-phenanthrenequinone nitro derivatives with anthracene. By electron spectroscopy it is established that the acceptor properties of the former increase with increasing number of nitro groups and depend on their position. 1,3,6-Trinitro-9,10-phenanthrenequinone, which forms with anthracene a CTC with a charge transfer band near 658 nm, is found to be the strongest acceptor. Charge transfer values from the donor (D) to the acceptor (A), ranging from 0.034 ē to 0.091 ē, formation energies of [A–D] complexes, HOMO and LUMO gaps in CTC are found by quantum chemical calculations, and they correlate with the experimental positions of long-wave bands in the electron absorption spectra of the complexes in solutions. The crystal and molecular structures of new 1:1 CTC of 2,4,7-trinitro-9,10-phenanthrenequinone with anthracene is determined by single crystal X-ray diffraction. In crystal, CTC has a {⋯[A–D]⋯[A–D]′⋯}∞ packing of the mixed type where average interplanar distances are 3.35 Å, with the shortest C⋯C distance being 3.234(2) Å, and intermolecular C–H⋯O hydrogen bonds are in the range 2.50-2.69 Å. © 2021, Pleiades Publishing, Ltd.