
%0 Journal Article
%A Finney, AJ 
%A Hitchman, MA 
%A Raston, CL 
%A Rowbottom, GL 
%A White, AH 
%T Structural and spectroscopic studies of transition metal nitrite complexes. III. Crystal structures and spectra of Aquabis(<I>meso</I>-1,2-diphenylethane-1,2-diamine)-nitronickel(II) perchlorate and Bis(<I>meso</I>-1,2-diphenylethane-1,2-diamine)-(nitrito-O,O')nickel(II) chloride
%J Australian Journal of Chemistry
%D 1981/10/01
%V 34
%N 10
%P 2069-2084
%K 
%R https://doi.org/10.1071/CH9812069
%U https://www.publish.csiro.au/paper/CH9812069 
%X The crystal and molecular structures of the complexes [Ni(mstien),(NO2)(H2O)] ClO4 and [Ni(mstien)2(O2N)] Cl are reported (mstien = meso-stilbenediamine, 1,2-diphenylethane-1,2-di-amine). Both compounds contain nickel(II) in an essentially octahedral ligand environment. In the latter complex, the nitrite ion chelates, while in the former it is present as a nitro group situated trans to a coordinated water molecule. In both complexes the conformations observed for the amine chelate rings can be rationalized on the basis that they minimize intramolecular ligand repulsions. The complex [Ni(mstien)2(O2N)] NO2 is isomorphous with the analogous chloride compound, and spectral evidence suggests that the complex [Ni(mstien)2(O2N)] ClO4 also contains a chelating nitrite group. The electronic spectra of single crystals of [Ni(mstien),(O2N)] X (X = Cl- and NO2-) show bands centred at c. 25000 cm-l which exhibit vibrational fine structure. The energies of the progressional spacings are c.600cm-l, which suggests that the bands are probably due to n &#8594; &#960;* internal nitrite transitions. The band centred at c. 20500 cm-1 in [Ni(mstien)2(NO2)(H2O)] ClO4 also shows well resolved vibrational fine structure with a progressional spacing of c. 630 cm-1. This implies that the band is not due to a 'd-d' transition, but must be caused by the excitation of an electron into the nitrite &#960;* orbital, either from a non-bonding nitrite orbital, or more probably from the nickel ion. 
