Springer Online Journal Archives 1860-2000
Chemistry and Pharmacology
Abstract The crystal structures of the two clathrates with the composition [M(4-MePy)4(NCS)2]·0.67(4-McPy)·0.33 H2O (M=Cu(II), Mn(II); 4-MePy=4-methylpyridine) have been determined. These compounds are trigonal, with the [M(4-MePy)4(NCS)2] host molecules being centrosymmetric. The parameters of the unit cells area = 27.365(7) and 27.738(6),c = 11.303(9) and 11.250(8) Å,V = 7325(2) and 7493(2) Å3, space group R $$\bar 3$$ , R = 0.053 and 0.109 for M = Cu(II) and Mn(II), respectively. ForZ = 9d calcd is equal to 1.271 and 1.225 g/cm3, andd measd is equal to 1.252(2) and 1.213(2) g/cm3 for the Cu and Mn clathrates, respectively. The coordination environment of the metal atoms in these compounds is an irregular octahedron, while in the Mn compound these distortions are rather small (Mn-NMePy 2.30, 2.34 Å, Mn-NNCS 2.18 Å, and Cu-NMePy 2.06 Å, Cu-NNCS 1.98 Å and Cu-NMePy 2.50 Å). The molecular packing in the structures is such that the channels of variable diameter are formed along the short cell dimension (the maximum diameter is ≅ 10 Å, the minimum being ≅ 6 Å) where the guest 4-MePy and H2O molecules are placed.
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