V. V. Gritsenko

Novel packing type of ET radical cation layers in a new organic conductor (ET)5[Dy(NCS)6NO3]·C2H5OH with a metal-complex lanthanide anion

Abstract A new radical cation (ET) 5 [Dy(NCS) 6 NO 3 ]·C 2 H 5 OH salt was prepared by electrochemical oxidation of ET in a chlorobenzene–ethanol solution. Its crystal structure and conducting properties were examined. The salt has a layered crystal structure with a basically new packing type of the radical cation layer, which was called an ω-type. Resistance studies reveal a semiconducting nature of this salt.

Structure of some molecular conductors with rare-earth metal counter-anions

New radical cation salts(ET) 5 [M(NCS) 6 NO 3 ] C 2 H 5 OH (M = Dy, Y) were prepared. The salts have a layered structure with a new ω-type packing type of the ET molecules.

Highly conducting DOET salts

A series of radical cation salts based on nonplanar DOET [(1,4-dioxanediyl-2,3-dithio)ethylenedithiotetrathiafulvalene ] donor with the ReO 4 - , HSO 4 . , FSO 3 - Hg 2 Br 6 -2 , Hg 2 CL 6 -2 , NO 3 - , SiF 5 - anions has been synthesized. Crystal structures and conducting properties have been studied. The first DOET salt retaining metallic state down to 4 K has been found.

Electronic properties of BETS superconductors with magnetic anions (BETS=bis(ethylenedithio)tetraselenafulvalene)☆

The physical properties of BETS (=bis(ethylenedithio)tetraselenafulvalene) conductors with tetrahalide magnetic anions and related systems were investigated. We have recently succeeded to find the superconducting transition of the crystal of K-type T1C1 4 - salt coated with epoxy resin (T c (onset) = 2.5 K). The specific heat measurements on the antiferromagnetic organic superconductor, k(BETS) 2 FeCl 4 was performed down to 60 mK, which gave sharp peak at 0.45 K (T N ). The peak trails a tail at T > T N , suggesting low-dimensionality of the spin system. Resistivity measurements under magnetic field of λ-(BETS) 2 Fe x Ga 1-x Cl 4 x 0.4) exhibiting superconductor-to-insulating (SC-I) transition, I-SC phase transition was observed around 4 T at T < 3 K. The low-field superconducting region between metallic and insulating phases around zero magnetic field is connected with the high-field superconducting region.

Magnetic Organic Superconductors Based on BETS Molecules--Interplay of Conductivity and Magnetism

Among six BETS (=bis(ethylenedithio)tetraselenafulvalene) superconductors, the systems with FeX 4 m (X=Cl, Br) anions exhibit salient electronic properties due to the coupling between ~ and d electron systems. u -BETS 2 FeCl 4 undergoes successive transitions as, antiferromagnetic insulating phase M metallic phase with ferromagnetically oriented Fe 3+ spins M superconducting phase ( H //conduction plane) M metallic phase, with increasing magnetic field. s -BETS 2 FeX 4 exhibits successive antiferromagnetic and superconducting transitions with decreasing temperature. Resistivity anomaly observed at antiferromagnetic transition temperature indicates an evidence for the coupling between ~ and d electron systems. antiferromagnetic organic superconductor BETS magnetic organic superconductor organic superconductor

Synthesis and crystal structure of (BEDT-TTF)4Cd2I6 and (BEDT-TTF)2Cd3I6 ion-radical salts

Abstract New ion-radical salts with iodine-cadmiate anions, (BEDT-TTF) 4 -Cd 2 I 6 and (BEDT-TTF) 2 Cd 3 I 6 , have been synthesized and their compositions and structures have been determined with the X-ray analysis. Both compounds are characterized with the alternation of organic layers formed of the BEDT-TTF molecules with inorganic ones composed of discrete anions [Cd 2 I 6 ] 2− in ET 4 Cd 2 I 6 and representing a polymeric net (Cd 3 I 6 ) n in ET 2 Cd 3 I 6 .

Structures and conductivities of isostructural synthetic metals (DOET)4[Hg2Cl6] and (DOET)4[Hg2Br6]

The structures of organic metals (DOET)4[Hg2Cl6] (1) and (DOET)4[Hg2Br6] (2), where DOET is (1,4-dioxanediyl-2,3-dithio)ethylenedithiotetrathiafulvalene, were established by X-ray diffraction analysis. Compounds 1 and 2 are isostructural, and their crystals have layered structures. The conducting layers formed by the stacked DOET1/2+ cations alternate with the layers of the [Hg2X6]2– anions (X = Cl, Br). The temperature dependence of the conductivity of salt 1 shows a metallic character in the range of 300—4 K. Compound 2 undergoes the metal—semiconductor phase transition (TM—I) at 100 K.

BETS-Based Molecular Conductors with Tetrahedral Anions TlCl4–, MnBr42–, CoCl42– (BETS = Bis(ethylenedithio)tetraselenafulvalene)

Molecular conductors on the basis of bis(ethylenedithio)tetraselenafulvalene (BETS) with tetrahedral anions TlCl4–, MnBr42–, and CoCl42– were synthesized and studied by X-ray diffraction analysis. The salts under study exhibit various conducting properties: κ-(BETS)2TlCl4 (I) is a superconductor with Tc = 2.5 K, θ-(BETS)4MnBr4 · 2C2H5OH (II) is a metal up to ≈30 K, while (BETS)2CoCl4 (III) is a dielectric. Salt I has κ-packing of the donor molecules, salt II has θ-packing, whereas salt III has no conducting layers. These structural differences are mainly the reasons for different conducting properties of compounds I–III.

Influence of Packing of Radical Cations on the Conductivity of the New Molecular Semiconductor (Doet)2ReO4

A new molecular semiconductor, (Doet)2ReO4(Doet is (1,4-dioxanediyl-2,3-dithio)ethylenedithiotetrathiafulvalene), is synthesized and examined by X-ray diffraction analysis. The crystal structure of (Doet)2ReO4is formed by [Doet]+1/2layers with isle [ReO4]–anions located between them. The Doet radical cations from the adjacent layers are linked by intermolecular hydrogen interactions of the O···H type.

X-ray structure of the organic conductor (ET)8[Hg2Br6·PhBr]2

AbstractThe electrochemical oxidation of ET [bis(ethylenedithio)tetrathiafulvalene] in bromobenzene (electrolyte Bu4N[HgBr3]) gave the radical-cation salt (ET)8[Hg2Br6·PhBr]2 (1), a new organic metal with a temperature range of 300–125 K. At 125 K a metal—dielectric transition is observed. Crystallographic data for (1):a=19.171(6),b=12.668(4),c=17.777(6) Å, α=118.03(3), β=89.45(2), γ=101.21(3)°, P