Radical Cation Salts of Tetramethyltetrathiafulvalene (TM-TTF) and Tetramethyltetraselenafulvalene (TM-TSF) with Chlorocyananilate-Based Anions

Abstract

Electrocrystallization of tetramethyltetrathiafulvalene (TM-TTF) and tetramethyltetraselenafulvalene (TM-TSF) with chlorocyananilate monoanion or/and tris(chlorocyananilato)ferrate(III) in THF/DCM solvent mixtures yielded a salt formulated as [TM-TTF] 4 [K(HClCNAn) 4 ] (1) with the former and π−d hybrid systems, formulated as [TM-TTF] 5 [Fe 3), respectively, with the latter. Compound 1 shows segregation of TM-TTF donor molecules and K(HClCNAn) 4 anionic clusters in the bc plane. The donor molecules are present as mixed-valence dimers and show a β′ packing arrangement. Compounds 2 and 3 consist of hybrid organic/inorganic structures with no segregation of [Fe(ClCNAn) 3 ] 3− anionic complexes and organic TM-TTF/TM-TSF donors. In the structure of compound 3, TM-TSF dimers are trapped between anilate units of metal complexes of opposite chirality. Furthermore, tetrameric donor motifs and solvent molecules of crystallization complete the structure. Single-crystal conductivity measurements on compounds 1 and 2 show semiconducting behavior with room-temperature conductivity values of 5 × 10 −5 and 2 × 10 −4 10 S cm −1 and activation energies of 1960 and 1900 K, respectively. Under high pressure, compound 2 remains a semiconductor, yet its room-temperature conductivity value strongly increases up to 0.2 S cm −1 at 9.8 GPa.

Inducing Structural Diversity in Anionic Metal–Tetraoxolene Coordination Polymers Using Templating Methyl Viologen Countercations

“…Remarkably, functional or redox-active cations have seldom been used as countercations for anionic metal–tetraoxolene compounds, − so the ability of such cations to influence the structure and properties of tetraoxolene coordination polymers is largely unknown. Quaternized bipyridinium cations, termed viologens, are a particularly interesting class of functional cation and have been widely incorporated into a range of materials such as electrochromics , and molecular switches. , This stems largely from the tunable redox activity of viologens , and their ability to engage in both supramolecular heterophilic charge-transfer interactions with π-electron rich species , and homophilic radical–radical interactions. , We recently introduced an approach using viologen-like redox-active countercations to guide assembly of a mixed-valence Fe–tetraoxolene coordination polymer .…”

New Radical-Cation Salts Based on the TMTTF and TMTSF Donors with Iron and Chromium Bis(Dicarbollide) Complexes: Synthesis, Structure, Properties

“…Although most of the compounds studied were BEDT-TTF-based radical-cation salts, recently, we have synthesized radical-cation salts based on such unconventional and rather exotic donors as bis (1,3-propylenedithio)tetrathiafulvalene [8,9], dibenzotetrathiafulvalene [10], and 4,5-ethylenedithio-4 ,5 -(2-oxa-1,3-propylenedithio)-tetrathiafulvalene [9]. On the other hand, although compounds of the composition (TMTXF) 2 Y (X = T, S) are usually classical organic metals among which the first organic superconductors were discovered [4,7], and TMTTF and TMTSF radical-cation salts continue to attract the attention of researchers [11][12][13][14][15], very little attention has been paid to TMTTF and TMTSF radical-cation salts with metallacarborane anions [16][17][18][19]. This prompted us to prepare and investigate new TMTTF and TMTSF radical-cation salts with metallacarborane anions.…”