Crystal Structures of Tris(ethylenediamine)cobalt(III) [Co(En)_3]_6Pb(NO_3)_(20) centre dot 4H_2O and Tris(l,10-phenanthroline)cobalt(III) [Co(Phen)_3]_2Pb_3(NO_3)_(12) centre dot 4H_2O Nitratoplumbates(II)

摘要

The crystal structures of [Co(En)_3]_6Pb(NO_3)_(20) centre dot 4H_2O (I) and [Co(Phen)_3]_2Pb_3(NO_3)_(12) centre dot 4H_2O (II) (En is ethylenediamine and Phen is 1,10-phenanthroline) were determined. In addition to the [Co(En)]~(3+) complexes, isolated nitrate ions, and crystal water molecules, the structure of I contains the [Pb(NO_3)_5(H_2O)_2]~(3-) complex anions. The coordination sphere of the Pb atom (CN =10) located on axis 2 is formed by O atoms of two monodentate nitrate ions, the O atoms of two water molecules, and six O atoms of three bidentate nitrate ions. The crystals of II contain the [Co(Phen)_3]~(3+) ions, Pb_3(NO_3)_(12)(H_2O)_2~(6-) trinuclear complexes, and crystal water molecules. In the centrosymmetrical trimer, the Pb(1) atoms occupy general positions and are surrounded by ten O atoms of five nitrate ions. The Pb(2) atoms are located near the inversion centers; their nearest environment includes the O atom of the water molecule, the O atoms of two nitrate ions of the neighboring [Pb(l)(NO_3)_5]~(3-) fragments, and the O atoms of the other two nitrate ions related by an inversion center. Due to the disorder of the atoms of these nitrate ions and of the Pb(2) atom itself, the Pb(2) coordination sphere is not identical throughout the crystal of II.