Crystal and molecular structure of 1,3,4,6-etraphenylimidazolio[4,5-d]-imidazolium bis(phenylenedioxytetrachlorophosphate)

X-ray diffraction structural study of a novel aromatic 10π-electron system of 1,3,4,6-tetraphenyl-imidazolio[4,5-d]-imidazolium bis(phenylenedioxytetrachlorophosphate) is carried out. The crystals are monoclinic; a = 8.483(2) Å, b = 23.986(4) Å, c = 10.727(2) Å; β = 106.84(2)°; V = 2089.1(7) Å3, space group P21/n. The compound crystallizes as a salt containing two phenylenedioxytetrachlorophoshate anions per one dication of 1,3,4,6-tetraphenylimidazolio[4,5-d]imidazolium. The cation occupies a special position on the inversion center. There are short C-H...X (X = O, Cl) contacts and π-π-interactions between aromatic fragments in the crystal and their combined effect results in the development of a layered structure.