The crystal structure of 1,3,5-triphenylbenzene

1.3.5-Triphenylbenzene crystals are or thorhombic hemihedral , space group Pna2t, 7-47 X 19-66 X 1119 h a, M = 306-14, ~ = 1221 g.cm. -3, N ---4. The s tructure was solved by tr ial-and-error methods and then by twoand three-dimensional Fourier syntheses. The molecules, which form an approximate ly layer ar rangement , are not planar, the subs t i tu ted phenyl groups being twis ted about the formal single bonds by ( + 3 4 ° , --27 ° , +24 ° ) ± 2 ° respectively, out of the plane of the central ring. The average C-C bond length in the rings is 1.39±0.03 /~ and be tween rings it is 1.50±0.03 /~. The physical properties of the crystal may be explained in terms of the structure.