Correlation of 35c1 Nuclear-quadrupole Coupling Constants

From a consideration of odd-even intramolecular electron transfer processes in octahedrally co-ordinated transition metal complexes, two relationships have been derived. The first correlation describes 71 —> y3 optical electron transfer bands of the complexes K20sC l6 , K2IrCl6 , K2PtCl6 , K2PtCl4 as a function of the respective 35C1 nuclear quadrupole coupling constants. The second rela­ tionship correlates 7T->y5 optical charge transfer transitions of the substances K2ReCl6, K20sCl6,K 2IrCl6 with the 35C1 nuclear quadrupole coupling constants of these compounds. By using this charge transfer model, a linear relationship has been verified between the optical electronegativity values of the quadrivalent transition metal ions W4®, Re4®, Os4®, Ir4®, Pt4® and the 35C1 nuclear quadrupole coupling constants of their hexachloro complexes. The empirically established equation ^Men+ = e2 O a \ mol which describes the 35C1 n.q.r. frequencies of the hexachloro complexes of 2 h /a® Cl Re4®, Os4®, Ir4®, Pt4® and Pd4® as a function of the optical electronegativity values % of these metal ions, has been used to estimate 35C1 nuclear quadrupole resonance frequencies of chloro complexes as yet not probed by nuclear quadrupole resonance spectroscopy, e.g. Z e i s e’s salt (KPtCl3C2H4) , K3IrCl6 , K2RuC16 , K3RhCl6 and K3MoCl6 . Conversely, by the same procedure the optical electronegativity y of W4® and Au3® has been estimated from the 35C1 quadrupole reso­ nance frequency of K2WC16 and KAuC14 (^ W 4® = 1.71 and Au3® = 2 .8 0 ). In the case of ana­