ISSN:
1089-7690
Source:
AIP Digital Archive
Topics:
Physics
,
Chemistry and Pharmacology
Notes:
Single crystals of [Fe(mesitylene)2+2][C3(C(CN)2)−3]2 exhibit an intense EPR spectrum with anisotropy and fine structure typical of an electronic triplet species (S=1). From measurements of the fine-structure splitting as a function of angle in three orthogonal crystal planes, it has been established that the spin–spin interaction tensor is nearly axial, D=(−218, 116, 105 MHz), and that the g tensor is almost isotropic with giso =2.0027. The zero-field splitting parameters were determined as ||D||=327.8 MHz (117 G) and ||E||=5.7 MHz (2 G). Comparison of the principal directions of D with vectors within the known crystal structure shows that the triplet comprises a radical pair formed between nearest neighboring anions. The principal values and directions of D for the biradical compare well with those calculated for the unpaired spin density distribution deduced for the monoradical from its isotropic spectrum and from INDO calculations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.459055
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