“…Hayter and Humiec25 have reported a rather unusual group of compounds which can be isolated in tetrahedral and planar forms as rather stable, solid compounds, among which is [n-C3H7P(C6H5)2]2NiBr2. Bis(dibenzoylmethanato)nickel(II) has been isolated in isomers of two different colors:57 one diamagnetic and monomeric with a square-planar distribution of the oxygen atoms about nickel (compound 56) and the other paramagnetic and trimeric with an octahedral distribution of the oxygen atoms about nickel (compound 12).14 Similarly bis(/V-methylsalicylaldimine)nickel(II) also occurs in diamagnetic and paramagnetic isomeric forms (compounds 55 and 13, planar and octahedral, respectively).15 Figure 3 (not corrected for sample charging) shows the XPS spectra of the latter pair of compounds (55 and 13). We see that the planar isomer (55) does not show any shake-up satellites, whereas for the octahedral isomer, compound 13, shake-up satellites appear at 860.2 and 878.5 eV.…”