Electronic Structure and Magnetic Interactions in the Radical Salt [BEDT-TTF]₂[CuCl₄]

Abstract

The magnetic behavior and electric properties of the hybrid radical salt [BEDT-TTF][CuCl] have been revisited through extended experimental analyses and DDCI and periodic DFT plane waves calculations. Single crystal X-ray diffraction data have been collected at different temperatures, discovering a phase transition occurring in the 250-300 K range. The calculations indicate the presence of intradimer, interdimer, and organic-inorganic π-d interactions in the crystal, a magnetic pattern much more complex than the Bleaney-Bowers model initially assigned to this material. Although this simple model was good enough to reproduce the magnetic susceptibility data, our calculations demonstrate that the actual magnetic structure is significantly more intricate, with alternating antiferromagnetic 1D chains of the organic BEDT-TTF radical, connected through weak antiferromagnetic interactions with the CuCl ions. Combination of experiment and theory allowed us to unambiguously determine and quantify the leading magnetic interactions in the system. The density-of-states curves confirm the semiconductor nature of the system and the dominant organic contribution of the valence and conduction band edges. This general and combined approach appears to be fundamental in order to properly understand the magnetic structure of these complex materials, where experimental data can actually be fitted from a variety of models and parameters.

Elucidating the Electronic Structure and Magnetic and Conducting Properties of μ-Oxo Mn-phthalocyanine [MnPc(CN)]2O Complex

“…Hence, it gives information about the nature of the π–π interaction and a qualitative estimate of its amplitude. At this level, J ππ is as large as −586 cm –1 , in the same range as that observed for through-space interactions between organic radicals such as the BEDT-TTF + cations (BEDT-TTF = bis­(ethylenedithio)-tetrathiafulvalene) or the neutral TTTA radicals (TTTA=1,3,5-trithia-2,4,6-triazapentalenyl) radicals …”

Bis-TTF-Ge derivatives: promising linear and nonlinear optical properties, a theoretical investigation

“…43 In addition, the nonlinear optical responses of several square-planar metal TTF complexes 44,45 have been studied theoretically and experimentally and have shown the important role of the ligand in perturbing the electron distribution in these complexes and its effect on both the ground and the excited states and, thus, on the linear and nonlinear optical properties. 46–51 In recent years growing attention has been expressed concerning germanium, and this interest is due to its high carrier mobility, good stability so that Ge is the most logical candidate to substitute carbon; moreover, it has also potential applications in photodetectors and nonlinear optical fields. 52–60…”

Bis(triphenylphosphine)iminium Salts of Dioxothiadiazole Radical Anions: Preparation, Crystal Structures, and Magnetic Properties

“…Achievement of such advanced properties requires, however, an expansion of the library of easily accessible and electroactive molecules with relatively stable radical forms. The most commonly studied radicals comprise α-diimines [12], dithiolenes [13][14][15], oxolenes [16,17], nitronyl nitroxides [18,19], tetrathiafulvalene (TTF) derivatives [20], π-conjugated macrocycles [21], TCNE and TCNQ derivatives [22][23][24][25], and verdazyl radicals [26].…”