X-RAY-DIFFRACTION STUDY OF THE CLATHRATE [MNPY4(NO3)(2)]CENTER-DOT-2PY AND COMPLEX [MNPY3(NO3)(2)] FORMED IN THE PYRIDINE (PY)-MANGANESE NITRATE SYSTEM

A clathrate compound [MnPy4(NO3)(2)] . 2Py was synthesized and studied by single-crystal X-ray diffraction analysis (KM-4 diffractometer, Cu Kalpha, omega/2 theta scan mode, theta(max) = 78 degrees). The unit ce ll is base-centered orthorhombic, space group Ccca, a = 12.097(4), b = 15.197(4), c = 17.213(4) Angstrom, V = 3164(2) Angstrom(3), Z = 4, R = 0.072, for 632 reflections and 107 parameters in the least-squares a nalysis. The host molecule has 222 symmetry. Two monodentate nitrato g roups and four pyridine ligands are coordinated to Mn(II) along the sy mmetry axes (the former via O). The pyridine guest molecules lie in th e cavities of the crystal framework. Far [MnPy3(NO3)(2)], only unit ce ll parameters were determined: a = 12.467(5), b = 9.514(2), c = 16.383 (5) Angstrom, beta = 108.93(4), V = 1838(1) Angstrom(3) space group C2 /c or Cc (according to extinctions). The pyridine-manganese nitrate sy stem is shown to be analogous to the previously investigated Co, Ni, C u, Zn, and Cd systems.