J. Haigh, N. Slabbert, D. A. Thornton
1971
Citations
0
Influential Citations
16
Citations
Journal
Journal of Molecular Structure
Abstract
Abstract Thirty-two octahedral bis(amine) adducts of nickel(II) acetylacetonate of general formula [Ni(AA) 2 B 2 ] (AA = acetylacetonate ion; B = variously substituted pyridines and anilines) have been synthesized and their infrared spectra determined. Adduct formation leads to a reduction in the Ni-O stretching frequency v (Ni-O) which is greater than that resulting from hydration. Correlations between v (Ni-O) and the electronic effects of the substituents (σ) show that increased donor capacity of the amine nitrogen for the metal ion caused by electron releasing substituents leads to a reduction in the Ni-O bond order and an increase in the C-O bond order. This effect is the opposite of that induced by substitution of the β-ketoenolate ring. Recently revised assignments of v (Ni-O) based on 18 O-labelling studies are supported by the present work.