Knowledge Bank

The ESR spectra of manganese (II)-doped single crystals of trigonal tris (octamethylpyrophosphoramide) magnesium (II) and -zinc (II) perchlorates have been examined. Identical results were obtained for both lattices with $D=146\times 10-4$ $cm-1$, $A\eta =99.5\times 10-4$ $cm-1$ and $A\perp =99.9\times 10-4$ $cm-1$. The g-value is essentially isotropic and close to the free electron value. The large managanese nuclear hyperfine splitting constants are accounted for by the appreciable ionicity of the lattice. The results are in accord with electronic spectral data for other metal complexes with octamethylpyro-phosphoramide. The ESR spectra of Mn(antipyrine)$\mathrm{<mrow\; data-mjx-texclass="ORD">6</mrow>}$ $(CIO4)2$ doped into single crystals of the corresponding divalent magnesium, cobalt, nickel, zinc and cadmium complexes exhibit appreciable variation of electric field parameters. The nuclear hyperfine splitting constants are smaller than in the octamethylpyro-phosphoramide (OMPA) complexes. The ESR spectra of manganese (II) doped into polycrystalline samples of polymeric $MHg(SCN)4$(M = divalent ion, e.g., $Zn2+)$ complexes have also been obtained. The presence of forbidden lines in the spectra enable structural parameters to be evaluated. The Magnion MVR-12X ESR spectrometer employed in this work was purchased with National Science Foundation Grant GP-18397. The authors are grateful to Professor M. Joesten, Vanderbilt University, for the OMPA complexes.