Determination of the Stereochemistry of Manganese(II) Complexes by Electron Spin Resonance

The co-ordination of small molecules by manganese(II) phosphine complexes. Part 11. The co-ordination of dioxygen by manganese(II) complexes containing long-chain phosphine ligands

“…In general the magnitudes of the equilibrium constants for 0, binding by long-and short-chain phosphine complexes are similar. The Hill coefficients, n, for the reactions of the chloride and bromide complexes with O2 in thf are close to unity, indicating no co-operative effects in binding, which is in keeping with the monomeric structure proposed, (11). On the other hand, in toluene solution n lies in the range 1.1% 1.64, indicating co-operativity, which may well be due to the effect of the dimeric structure proposed, (I).…”

Trigonal‐Prismatic vs. Octahedral Geometry for MnII Complexes with Innocent Didentate Ligands: A Subtle Difference as Shown by XRD and DFT on [Mn(acac)2(bpy)]

“…Although the exact magnitudes of the zerofield splitting parameters D, E and λ (= E/D) have not been calculated, it is clear from literature that D is likely to be significant (0.05 Ͻ D Ͻ 0.15 cm -1 ) and λ will approach its limiting value of 1/3. [26] The complex [Mn(acac) 2 (phen)] has a fairly regular octahedral coordination environment, which gives very small zero-field splitting values (D in the order of 10 -2 cm -1 , λ approximately 0) and thus a resonance signal near the free electron value of g = 2 is observed. [26] The similar solution-EPR spectra that are obtained demonstrate that in solution, the geometry around the Mn II ion is comparable for both complexes.…”

Diversity of chain, interwoven and network structures formed by metal complexes with 2,3,5,6-tetrafluoro-1,4-bis(4-pyridyl-sulfenyl)benzene †

“…Mn(py) 2 Cl 2 . 14 The X-ray powder patterns of MLCl 2 (M = Mn 1, Cd 12) show very marked similarities in the patterns of their principal lines, even to high angles, and although there is not a sufficient match to establish strict isomorphism it seems likely that the two compounds have basically the same type of polymeric structure. Accordingly we prepared Mndoped samples of CdLCl 2 (nominal 1% Mn doping) to investigate the EPR spectrum of the Mn centre in this type of polymeric array without the effects of the magnetic concentration present in 'normal' samples of MnLCl 2 .…”