Absolute configuration and optical activity of CdP2 tetragonal crystals

The atomic structure of crystals of tetragonal cadmium diphosphide CdP2 (a=5.2852(7), c=19.787(3)A, MoKα, 1201 unique reflections, R=2.5%, RW=2.4%) is refined by the X-ray diffraction method. The main structural elements of CdP2 crystals are -P-P-P-spirals forming with Cd atoms placed between them the layer pack. The trigonally distorted tetrahedron CdP4 is a coordination polyhedron Cd. Spirals in the layer pack are interleaved with bonds of CdP4 tetrahedrons jointed by vertices. It is established that in crystals of the left enantiomorphous form of tetragonal CdP2 for light propagating along the optical crystal axis the right-hand turn of the polarization plane is observed