A.I. Kotov

[Ni(dddt)2]3(HSO4)2, the first metal among the M(ddt)2 salts

Abstract The first metal, [Ni(dddt)2]3(HSO4)2, among the class of M(dddt)2 cation salts has been obtained. Its structure and conducting properties have been studied. [Ni(dddt)2]3(HSO4)2 has been found to be isostructural to the (ET)3(HSO4)2 salt and their conducting properties are compared. [Ni(dddt)2]3(HSO4)2 retains its metallic state to lower temperatures (∼ 25 K) than (ET)3(HSO4)2 (∼ 130 K).

Synthesis and characterization of new nickel and platinum complexes derived from the 5,6-dihydro-1,4-dithiin-2,3-dithiolate (dddt) ligand

Abstract Electrochemical studies shows that the M(dddt)2 (M = Ni,Pt) complexes exist as dianionic, monoanionic, neutral and fractional oxidation state cationic species. Associating the M(dddt)2 complexes with the Ni(dmit)2 acceptor yields a new type of bisdithiolene compounds containing a bisdithiolene ligand simultaneously in the cationic and in the anionic part. The two phases [Ni(dddt)2]x[Ni(dmit)2]y and [Pt(dddt)2][Ni(dmit)2] have been synthesized; both compounds are insulators (σpowder = 10−5 S/cm). The crystal structure of [Pt(dddt)2][Ni(dmit)2] is reported. The TTF[Ni(dddt)2]x salt has been also prepared; its room-temperature single crystal conductivity is 10−5 S/cm.

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.

BEDT-TTF derivatives with one and two dioxane rings and their conductive salts

Abstract Electron donors 4,5-(1,4-dioxanediyl-2,3-dithio)-4′,5′-ethylenedithiotetrathiafulvalene (DOET) and 4,5;4′,5′-bis (1,4-dioxanediyl-2,3-dithio) tetrathiafulvalene (BDDT) have been synthesized and their molecular and crystal structures have been solved. DOET and BDDT were shown to have bath conformations. Radical cation salts based on these donors have been prepared. The structure of the organic metal (DOET) 2 HSO 4 has been determined.

Structure of the neutral metal complex Pt(dddt)2

A neutral metal complex, [Pt(dddt)2]° (1), has been obtained by oxidation of the [Pt(dddt)2]− anion with excess (Bu4N)AuBr4 in nitrobenzene. Crystallographic data for 1∶a=17.854(9) Å,b=18.409(9) Å,c=4.717(5) Å, γ=68.83(2)°, space group P21/n,Z=4,dcalc=2.55 g/cm3. In1 two independent centrosymmetric [Pt(dddt)2]° molecules are packed in stacks that form layers parallel to the (110) plane. The molecules of1 in the layers have shortened S...S contacts 3.491(9) Å, and 3.594(10) Å. The average bond lengths Pt-S 2.242(7) Å, S-C 1.71(2) Å and C=C 1.40(3) Å, together with the square-planar coordination of Pt in PtS4, suggest considerable conjugation in the metal cycles.

The synthesis and first X-ray structures of nickel complexes of 1,2,5-thiadiazole-3,4-dithiolate

The (R4N)2[Ni(tdas)2] complexes (tdas2–= 1,2,5-thiadiazole-3,4-dithiolate and R = Bu, Et) are prepared and characterized by X-ray crystallography, which reveals differences in their structure dependant on the size of the R4N cation.

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.

Molecular metals based on pd(dddt)/sub 2/ complexes

Summary form only given. The M(dddt)/sub 2/ complexes (dddt2- = 5,6-dihydro-1,4dithiin-2,3 dithio late) arouse great interest for they are isolobal analogs of the molecule BEDT-TTF [1] which is known to form superconducting cation radical salts [2]. In this work the first cation salts of Pd(dddt)/sub 2/ with the anions different in their geometry and electronic configuration (IBr/sub 2/, C10/sub 4/, ZnC1O/sub 4/, PF/sub 6/, SnC1/sub 6/ etc) were prepared by electrochemical oxidation of Pd(dddt)/sub 2/ neutral complex. Some of them were found to be molecular metals. Properties and structure of Pd(dddt)/sub 2/ cation salts were compared with those of BEDT-TTF and Pt(dddt)/sub 2/ ones. In contrast to the latters with the octahedral doubly charged anions, which are dielectric at Low temperatures, Pd(dddt)/sub 2/ salt with TeC1/sub 6//sup 2-/ has high conductivity at 4.2 K (20 /spl Omega//sup -1/cm/sup -1/).