High Magnetization Reversal Barriers in Luminescent Dysprosium Octahedral and Pentagonal Bipyramidal Single-Molecule Magnets based on fluorinated alkoxides ligands.

We report the synthesis and structures of three luminescent dysprosium(III) complexes based on fluorinated alkoxide ligands of formulas [Dy(L1)2(THF)4][BPh4]•0.5THF (1), [Dy(L2)2(THF)5][BPh4]•2.5THF (2) and [Dy(L3)2(THF)5][BPh4]•2THF (3) (L1 = (CF3)3CO-, L2 =...

Theoretical investigation of experimentally determined α-εffects — The role of electronics

Recent experimental reports involving both α-nucleophiles and normal nucleophiles have reported both the presence and absence of an α-effect. In ester systems, such as dimethylmethylphosphonate (DMMP), a small α-effect is reported, but the reference point is a stationary point of the potential energy surface that must rearrange to acquire the near attack conformation (NAC) necessary for the Sn2 pathway to proceed. The second type of study involves use of highly fluorinated alkoxides as normal nucleophiles and reports no α-effect. This paper employs linear free energy plots in an investigation of electronic effects in methyl formate SN2 reactions, using high-level computations of transition states for determination of energy barriers.