New molecular superconductor containing paramagnetic chromium(iii) ions

Abstract

The molecular charge-transfer salt bB-(bedt-ttf) 4 [(H 2 O)Cr-(C 2 O 4 ) 3 ]•PhCN [bedt-ttf = bis(ethylenedithio)tetrathiafulvalene], containing paramagnetic Cr III ions (S = 3/2), is a superconductor with T c = 6.0(5) K.

Recent Advances on Anilato-Based Molecular Materials with Magnetic and/or Conducting Properties

“…The development of these π-d systems as multifunctional materials represents one of the main targets in current materials science for their potential applications in molecular electronics [78,[127][128][129][130]. Important milestones in the field of magnetic molecular conductors have been achieved using as molecular building blocks the bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) organic donor [123,[131][132][133] or its selenium derivatives, and charge-compensating anions ranging from simple mononuclear complexes [MX 4 ] n− (M = Fe III , Cu II ; X = Cl, Br) [134][135][136] In these systems the shape of the anion and the arrangement of intermolecular contacts, especially H-bonding, between the anionic and cationic layers influence the packing motif of the BEDT-TTF radical cations, and therefore the physical properties of the obtained charge-transfer salt [141]. Typically, the structure of these materials is formed by segregated stacks of the organic donors and the inorganic counterions which add the second functionality to the conducting material.…”

“…The introduction of chirality in these materials represents one of the most recent advances [144] in material science and one of the milestones is represented by the first observation of the electrical magneto-chiral anisotropy (eMChA) effect in a bulk crystalline chiral conductor [145], as a synergy between chirality and conductivity [146][147][148]. However, the combination of chirality with electroactivity in chiral TTF-based materials afforded several other recent important results, particularly the modulation of the structural disorder in the solid state , [130][131][132][133][134][135][136][137][138] and hence a difference in conductivity between the enantiopure and racemic forms [149][150][151] and the induction of different packing patterns and crystalline space groups in mixed valence salts of dimethylethylenedithio-TTF (DM-EDT-TTF), showing semiconducting (enantiopure forms) or metallic (racemic form) behaviour [152]. Although the first example of an enantiopure TTF derivative, namely the tetramethyl-bis(ethylenedithio)-tetrathiafulvalene (TM-BEDT-TTF), was described almost 30 years ago as the (S,S,S,S) enantiomer [153,154], the number of TM-BEDT-TTF based conducting radical cation salts is still rather limited.…”

Development of Conductive Organic Molecular Assemblies: Organic Metals, Superconductors, and Exotic Functional Materials

“…The paramagnetic organic superconductor, (1) with T c ¼ 7:0 K (on-set 8.6 K) was reported by Kurmoo, Day, and co-workers in 1995, 463 where early reports have indicated it as H 2 O instead of H 3 O þ . The corresponding Cr salt is also a superconductor, but with a slightly lower T c (6.0 K) than that of the Fe salt 464 (see Table 15). The crystal consists of alternating 2D layers of ET 0:5þ molecules and the other species that form the 2D honeycomb layer.…”

Hybrid Molecular Compound Exhibiting Slow Magnetic Relaxation and Electrical Conductivity

“…Hybrid molecular materials combining conductivity (delocalized electrons or holes) and magnetism (localized electrons) have been intensively studied in the past decades, in order to observe a synergy between these properties [1][2][3][4][5]. Organic conductors, such as bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF), and M(dmit) − (M: 3d or 4d metal; dmit: 4,5-dimercapto-1,3-dithiole-2-thione) with π electrons have been widely used in conducting materials, affording a large number of superconductors [3], such as paramagnet/superconductor, anti-ferromagnet/superconductor, and ferromagnet/metal [6][7][8].…”

“…Here, we reversed the roles of the donor and acceptor. We report a hybrid material, [β′-(BEDT-TTF)2Dy(CF3COO) 4•MeCN]n (1), with an anionic Dy III complex exhibiting slow relaxation of magnetisation and the organic conductor BEDT-TTF. To the best of our knowledge, this is one of few works in which slow relaxation of the magnetization from an f ion and molecular semi-conductivity have been combined [14].…”