Crystal structure of potassium heptacyanorhenate(III) dihydrate

Abstract

The crystal structure of K₄[Re(CN)₇]·2H₂O has been determined from three-dimensional X-ray diffraction data; 1 648 reflections have been observed and refined by least-squares methods to R= 0.012. The crystals are monoclinic, space group I2 with Z= 2, in a unit cell of dimensions a= 9.244(2), b= 8.998(2), c= 9.241(2)Å, and β= 92.53(2)°. The anion is pentagonal bipyramidal, with essentially similar Re–C axial [2.077(3)Å] and mean equatorial [2.090(5)Å] distances, and with mean C–N distances of 1.161 (5)Å. The structure is compared with those of other heptacyano-species.