Electron paramagnetic resonance bonding parameters

Globally following the method described in [17], the reduced SBs 1-7 depicted in Scheme 17.2 were prepared in alcoholic medium by the condensation of 1 equiv of the appropriate aldehyde with 1 equiv of amino acid in the presence of an equivalent of KOH. Treatment of these condensation products with NaBH4 resulted in the reduction of the imine bonds, yielding the reduced SBs. Five neat V O-complexes 8-12 (Scheme 17.2) were also prepared. The IR spectra of the solid V O-complexes present the characteristic v(V=0) bands at 950-1000 cm . The electron paramagnetic resonance (EPR) parameters for the five V O-compounds are listed in Table 17.1. For 9, 10,11, and 12, the parameters are consistent with either a (COO , 0 phenoiato- C>ROH)eq or a (COO-, 0"phe , ato, OoMF)eq donor set in methanol and dimethyl... 

Sinnecker S, Reijerse E, Neese E, Lubitz W. Hydrogen bond geometries from electron paramagnetic resonance and electron-nuclear double resonance parameters density functional study of quinone radical anion-solvent interactions. J Am Chem Soc 2004 126 3280-3290. 

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