Electron spin resonance spectra of manganese(II) ions in trigonal complexes of protonated 1,4-diazabicyclo[2.2.2]octane

Abstract

E.s.r. spectra are reported for manganese(II) ions doped into the polycrystalline complexes [Ni(HL⁺)₂Cl₃]Cl, [Ni(HL⁺)₂Br₃]Br, and [Zn(HL⁺)Cl₃](L = 1,4-diazabicyclo[2.2.2]octane) and the zero-field splitting parameters D and λ are calculated. All the three complexes give spectra interpretable in terms of an essentially trigonal field, but the two chloro-complexes show significant deviations from truly axial symmetry. All the three spectra show bands of appreciable intensity due to ‘off-axis’ transitions.