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A new family of six paramagnetic metals, namely, κ-(BDH-TTP)4CoCl4·(H2O)5 (I), κ-(BDH-TTP)4Co0.54Mn0.46Cl4·(H2O)5 (II), κ-(BDH-TTP)4MnCl4·(H2O)5 (III), κ⊥-(BDH-TTP)4CoBr4·(CH2Cl2) (IV), κ⊥-(BDH-TTP)4MnBr4·(CH2Cl2) (V), and κ⊥-(BDH-TTP)4MnBr4·(CH2Br2) (VI), has been synthesized and characterized by X-ray crystallography, four-probe conductivity measurements, SQUID magnetometry, and calculations of electronic structure. The newly discovered κ⊥-type packing motif of organic layers differs from the parent κ-type by a series of longitudinal shifts of BDH-TTP radical cations in the crystal structure. Salts I-VI form two isostructural groups: I-III (κ) and IV-VI (κ⊥). Salts I-III are isostructural to the previously discovered κ-(BDH-TTP)2FeIIIX4 (X = Cl, Br) even though the charge of FeX4- anions is half that of the MX42- (M = Co, Mn) anions. The tetrahedral anions are disordered in I-III but completely ordered in IV-VI. The type of included solvent molecule is solely determined by the anion size. The paramagnetic subsystem is effectively spin diluted either by anion disorder (I-III) or by spatial separation (IV-VI). The Weiss constants are virtually zero for all compounds (e.g., θ(III) = 0.0056 K, θ(V) = −0.076 K). Curie constants are dominated by anion paramagnetic centers indicating high spin states 5/2 for MnII and 3/2 for CoII with large spin-orbital coupling. All compounds retain metallic properties down to 4.2 K. There is a magnetic breakdown gap of width (w) in the chiral salts IV-VI: w(IV) > w(V) ≈ w(VI) but no gap in the centrosymmetric salts I-III. Electronic structure calculations at room temperature revealed a nearly isotropic triangular lattice in I-III and a honeycomb lattice in IV-VI with an extreme geometric spin frustration exceeding the level reported for the quantum "spin liquid" κ-(BEDT-TTF)2Cu2(CN)3. [ABSTRACT FROM AUTHOR]

The purely organic paramagnetic charge-transfer salt (TTF)3(PO-CON(CH3)C2H4SO3)2was prepared. The anisotropic anion forms a head-to-head arrangement in the anionic layer, giving dual donor layers with different oxidation states. SQUID magnetometry indicates that spins are localized not only on the free radical (PO) but also on both TTF layers. [ABSTRACT FROM AUTHOR]

We have prepared a novel organic molecule, 2-sulfo-3,5,6-trichloro-1,4-benzoquinone (1), that has both an electron acceptor part (chloranil) and an anionic part (sulfonate). The reduction potential of the PPh4salt is −0.34 V (vs.SCE in PhCN) which indicates it is a weaker acceptor than chloranil (−0.18 V). The anionic acceptor provided one TTF (tetrathiafulvalene) and two BEDT-TTF (bis(ethylenedithio)tetrathiafulvalene) salts, the structures and physical properties of which are reported. [ABSTRACT FROM AUTHOR]

κ-β′′-(BEDT-TTF)2(PO-CONHC2H4SO3) is the first stable metal containing an aminoxyl radical. The salt has both κ- and β′′-type donor sheets and exhibits metallic behavior down to 1.7 K. The magnetic susceptibility can be modeled by an alternate chain model with J1= −0.80, and J2= −0.69 K. [ABSTRACT FROM AUTHOR]

Radical-cation salts of formula β?-(BEDT-TTF)4[(H3O)Fe(C2O4)3]·guest have produced a large number of superconductors and provided a route to introduce magnetism and chirality into the same multifunctional material. A relationship has been found in these salts between the length of the b axis and the superconducting Tc. Increasing the b axis length by introducing larger guest molecules, such as benzonitrile and nitrobenzene, gives the highest superconducting Tcs in this family of salts. Smaller guests such as pyridine show no superconducting transition, whilst asymmetrical guests which are larger than nitrobenzene have given a different bilayered structure. Other potential guest molecules have been limited by their ability to be used as the solvent in which the crystals are grown via electrocrystallisation. This paper reports a method which introduces guest molecules into the crystal which are a solid or liquid additive within the crystal-growing solvent 1,2,4-trichlorobenzene:ethanol. We present the crystal structures of five new BEDT-TTF radical-cation salts with tris(oxalato)ferrate anions using guest molecules toluene, phenol, benzaldehyde, 4-bromobenzaldehyde, and kojic acid. [ABSTRACT FROM AUTHOR]

Heavily doped semiconductors are well investigated and widely used in inorganic electronics. However, controlled heavy doping of organic crystalline semiconductors is yet to be studied because of the lack of suitable methods. This article reports on doping by electrolyte gating combined with bandwidth control by uniaxial stress using a bilayered nonstoichiometric κ–β'-type charge-transfer salt, in which the β' layer exhibits competition between metallic and charge-ordered insulating states. A change from insulating-like to metal-like conduction with a positive temperature coefficient of resistance is induced by the simultaneous application of a negative gate voltage and compressive stress applied by bending the substrate. The simultaneous heavy doping and bandwidth-control technique presents a novel approach for investigating nonstoichiometric doping of organic semiconductors for novel electronic functions using metal–insulator transitions and superconductivity of correlated electron systems. [ABSTRACT FROM AUTHOR]

Dependence of the superconducting transition temperature (Tc) and critial superconducting pressure (Pc) of the pressure-induced superconductor β-(BDA-TTP)2I3 [BDA-TTP = 2,5-bis(1,3-dithian-2-ylidene)-1,3,4,6-tetra-thiapentalene] on the orientation of uniaxial strain has been investigated. On the basis of the overlap between the upper and lower bands in the energy dispersion curve, the pressure orientation is thought to change the half-filled band to the quarter-filled one. The observed variations in Tc and Pc are explained by considering the degree of application of the pressure and the degree of contribution of the effective electronic correlation at uniaxial strains with different orientations parallel to the conducting donor layer. [ABSTRACT FROM AUTHOR]