Gerald M. Woltermann

Single-crystal ESR spectra of tris(octamethylpyrophosphoramide) manganese (II) perchlorate

Abstract The ESR spectra of manganese(II)-doped single crystals of tris(octamethylpyrophosphoramide) zinc(II) perchlorate have been examined. The magnitude of the manganese nuclear hyperfine splitting parameter (≈99.7×10−4 cm−1 shows that this is one of the most ionic compounds ever investigated.

Complexes with sulfur and selenium donors-III: Proton nuclear magnetic resonance study of the morpholine adducts of bis(0,0′-dialkyldithiophosphato)nickel(II) complexes

Abstract Electronic and proton nuclear magnetic resonance spectra have been employed to elucidate the nature of the adducts formed by morpholine with a number of bis(0,0′-dialkyldithiophosphato)nickel(II) complexes, Ni(S 2 P( OR ) 2 ) 2 ( R = ethyl, n -propyl, iso propyl, iso butyl, sec -butyl, cyclo hexyl, and 2-phenylethyl). Upfield NMR contact shifts of the -NH- proton were used to assign metal-nitrogen coordination by morpholine. The morpholine adducts exhibit properties consistent with a 5-coordinate (∼C 4 v ) geometry. NMR contact shifts and electron spin-nuclear spin coupling constants are tabulated and electron delocalization mechanisms are discussed.

Allowed and forbidden transitions in the ESR spectra of manganese(II)-doped tris(octamethylpyrophosphoramide)magnesium(II) perchlorate

The ESR spectra of Mn(OMPA)3(ClO4)2 (OMPA = octamethylpyrophosphoramide) doped into the corresponding magnesium host lattice is reported. The electron spin-nuclear spin hyperfine coupling constant (106 gauss) is indicative of the highly ionic character of the manganese-oxygen bonding. The spectra were interpreted using an axially symmetric spin- Hamiltonian for an S= 52 spin state. The zero-field splitting is predominantly due to interaction of Mn(II) with the trigonal crystalline field. The magnitude and signs of the zero-field splitting parameters D and (a − F) were determined: D = 157 gauss, (a − F) = +9 gauss (g = 2.011). A nuclear quadrupole coupling constant of 0.154 gauss results from an analysis of the forbidden ESR lines.