6533b871fe1ef96bd12d0e61

RESEARCH PRODUCT

Charge transfer salts containing a paramagnetic cyano-complex and iodine substituted organic donor involving –I(donor)···N(anion)-interactions

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Abstract The preparation, crystal structures, EHT band calculation and optical properties of two new charge transfer salts, namely (DIET)2[Fe(bpca)(CN)3] (1) and (DIEDO)2[Fe(bpca)(CN)3] (2), where bpca = bis(2-pyridylcarbonyl)amide anion, DIET = diiodoethylenedithotetrathiavalene and DIEDO = diiodoethylenedioxotetrathiavalene are reported. The magnetic properties of 2 and those of the low-spin iron(III) precursor of formula (PPh4)[Fe(bpca)(CN)3]·H2O (3) were also investigated in the temperature range 1.9–205 K. Crystal data; (1): monoclinic P21, a = 8.8238(2)A, b = 13.2891(3) A, c = 18.5042(5) A, β = 91.115(1)°, Z = 2, R = 0.0710 for 7021 independent reflections with I > 2 σ(I) and (2): Monoclinic P21/c, a = 8.6870(1) A, b = 12.6122(2) A, c = 36.0277(11) A, β = 90.380(5)°, Z = 4, R = 0.0602 for 4633 independent reflections with I > 2σ(I). The crystal structures for both compounds consist of alternating organic and inorganic layers. Compounds 1 and 2 exhibit semiconductive behavior. Simple tight-binding band calculations indicate quasi one- (1) and two-dimensional (2) electronic band structures. The magnetic properties of 2 compared to that of the low-spin iron(III) precursor 3 (which was used as a blank) reveal the occurrence of a relative large antiferromagnetic interaction between the DIEDO radical units, however, below 30 K, the magnetic behavior of 2 is indistinguishable from 3. To cite this article: L Ouahab et al., C. R. Chimie 8 (2005).