The preparation of a series
of novel compounds of general formula [Ni5L4(NO2)8(OH)2]
formed by ethane-1,2-diamine or one of five N-substituted
ethane-1,2-diamines (L) is described. The crystal and molecular structures of
the ethane-1,2-diamine, N,N'-diethylethane-1,2-diamine
and N,N-dimethylethane-1,2-diamine
complexes are reported. Each compound contains a planar, pentameric
arrangement of nickel(II) ions, linked by bridging hydroxide and nitrite
ligands. The details of the nitrite bridges differ among the complexes, causing
differences in their electronic and infrared spectra. The structural variations
are probably caused by the differing steric requirements of the amine
substituents.
