Structure of the “blue” clathrate [Cu(MePy)4(NCS)2]-2MePy

Abstract

The structure of the single crystal of the “blue” clathrate [Cu(MePy)4(NCS)2 ]-2MePy was determined by XRD. The unit cell is monoclinic P21 with parameters a = 10.97(3), b = 11.275(7), c = 16.144(8) a, Β = 105.8(1)‡, Z = 2, pcalc = 1.277 g/cm3 at — 120‡C, pexp = 1.229 g/cm3 at 0‡C. The total number of measured reflections is 3720, including 3525 independent ones. For structure refinement, 1395 reflections were used. The final R is 0.079 for observed reflections and 0.209 for all 3525 independent reflections. The central atom of the complex host (copper) molecule is coordinated quasioctahedrally (4+ 2) by six nitrogen atoms, as in the case of the “green” clathrate [Cu(MePy)4(NCS)2] — 2/3MePy. In contrast to the centrosymmetric host molecule of the latter, in the “blue” clathrate the host molecule is very asymmetric. The molecular packing is of layered type. The layers of host molecules (the four 4-methylpyridine ligands lie in the plane of the layer) are separated by two symmetrically unrelated layers occupied by the 4-methylpyridine guest molecules. No chemical interactions have been found between the guest and host molecules. The isothiocyanate groups lie in the guest layer, dividing it into zigzag channels.