Electrical conductivities of bis(1,3-dithiole-2-thione-4,5-dithiolato)rhodate anion salts

RhCl₃·3H₂O reacted with Na₂dmit (dmit²⁻; 1,3-dithiole-2-thione-4,5-dithiolate anion) and [NBu₄ⁿOH in methanol to afford [NBu₄ⁿ][Rh(dmit)₂] (1) and [NBu₄ⁿ]_1.5[Rh(dmit)₂] (2). Salt 1 was oxidized electrochemically in acetonitrile to afford [NBu₄ⁿ]_0.4[Rh(dmit)₂] (3). Suspended powders of 1 or 2 reacted with iodine in hexane to afford [NBu₄ⁿ][Rh(dmit)₂][I₃]_1.3 (4) or [NBu₄ⁿ]_1.5[Rh(dmit)₂[I₃]_0.4 (5). On the other hand, 1 dissolved in acetonitrile, reacted with bromine and iodine to yield [NBu₄ⁿ]_0.25[Rh(dmit)₂Br] (6) and [NBu₄ⁿ]_0.35[Rh(dmit)₂I] (7), respectively. All the salts behave as semi-conductors with electrical conductivities of 1 x (10⁻⁵ − 10⁻⁸) S cm⁻¹ at 25°C measured for compacted pellets. Electronic absorption, ESR and X-ray photoelectron spectra of the salts are discussed.     

An experimental and theoretical study of the electronic spectra of tetraethylammonium [bis(1,3-dithiole-2-thione-4,5-dithiolato)M(III)] and tetraethylammonium [bis(1,3-dithiole-2-one-4,5-dithiolato)M(III)] (M = Sb or Bi)

Metal complexes of dmit and related ligands, such as dmio, have been studied extensively over the last few decades: [dmit](2-) = bis(1,3-dithiole-2-thione-4,5-dithiolato); [dmio](2-) = bis(1,3-dithiole-2-one-4,5-dithiolato). While much effort has been placed on determining structural properties, very few vigorous spectroscopic studies of these metal complexes have been undertaken. The spectroscopic features of the infrared, Raman and UV-vis spectra, previously reported, have largely been used to characterize compounds. In particular, many details of the electronic structure are still to be revealed. We now report a detailed analysis of the UV-vis spectra of the [M(dmit)](-1) and [M(dmio)](-1) anions, where M = Sb(III) or Bi(III). Experimental spectra were deconvoluted and analysed by several theoretical methodologies, including ab initio CI, TD and CISD calculations. The results led to the assignments of several MLCT/LMCT bands, occurring between 390 and 300 nm, and the confirmation of metal orbital contributions to the HOMO-LUMO boundary.     

Syntheses, crystal structures, and magnetic properties for two spin-ladder complexes based on bis(2-thioxo-1,3-dithiole-4,5-dithiolato)nickelate monoanion building block

Two isostructural complexes based on bis(2-thioxo-1,3-dithiole-4,5-dithiolato)nickelate monoanion ([Ni(Dmit)₂]^?) building block, (C₁₉H₁₁NNiF₃S₁₀ (I) and C₁₈H₁₀N₂F₃NiS₁₀ (II)), have been synthesized and characterized structurally and magnetically. Two complexes crystallize in monoclinic space group $P\bar 1$ with very similar cell parameters and packing structures. The planar [Ni(Dmit)₂]^? monoanions form face-to-face π-type dimer, and the neighboring dimers are aligned into a ladder-type arrangement via lateral-to-lateral S…S contacts along x axis in the crystals of I and II. Two complexes exhibit similar magnetic behaviors, and their magnetic susceptibility data can be fitted to a Heisenberg antiferromagnetic two-legged spin ladder formula in high-temperature region and reproduced well by the Troyer expression in low-temperature region. The spin-gap values, obtained, respectively, from the fits of magnetic susceptibility data in high- and low-temperature regions, are closed to each other, indicating the chose magnetic exchange model and the results of fits are reasonable.     

Synthesis and Crystal Structures of Bis(tetraethylammonium)(2-oxo-1,3-dithiole-4,5-dithiolato)zincate(II) and Bis(tetra-n-butylammonium)(2-oxo-1,3-dithiole-4,5-dithiolato)zincate(II)

The title compounds were prepared from 1,3,4,6-tetrathiapentalene-2,5-dione ( 1 ) in one step via the in situ generated intermediate 2-oxo-1,3-dithiole-4,5-dithiolate (dmid; 2 ). The X-ray single crystal structure of (Et₄N)₂[Zn(dmid)₂] ( 3 a ) gave the tetragonal space group P4₃2₁2 with a = b = 13.810(2) Å, c = 16.480(3) Å, and Z = 4. (n-Bu₄N)₂[Zn(dmid)₂] ( 3 b ) gave the triclinic space group P 1 with a = 11.947(4) Å, b = 14.665(5) Å, c = 16.662(8) Å, α = 100.21(3)°, β = 104.46(3)°, γ = 110.73(3)°, and Z = 2.     

Synthesis,crystal structure and saturable absorption in the near-IR regions of a new copper complex of dmit: hexadecyltrimethylammonium bis (2-thioxo-1,3-dithiole-4,5-dithiolato)-copper

A new copper complex of dmit, hexadecyltrimethylammonium bis(2-thioxo-1,3-dithiole-4,5-dithiolato)-copper([C₁₆H₃₃(CH₃)₃N][Cu(dmit)₂], abbreviated as CTCU, C₁₆H₃₃(CH₃)₃N = hexadecyltrimethylammonium, dmit = 2-thioxo-1,3-dithiole-4,5-dithiolate) has been synthesized and its structure determined by X-ray diffraction. The saturable absorption of CTCU at 1053 nm shows promise as a Q-switch dye in the near IR regions.     

Three new nickel(III) compounds based on 2-thioxo-1,3-dithiole-4,5-dithiolate: Syntheses,structures, magnetic properties and theoretical analyses

Three new molecular solids, (ADP)₂[Ni(dmit)₂]₂ (1), (BDP)[Ni(dmit)₂]·CH₃COCH₃ (2) and (CP)₂[Ni(dmit)₂]₃ (3) (dmit = 2-thioxo-1,3-dithiole-4,5-dithiolate, ADP = 1-(2,4-dichlorobenzyl)-3,5-dimethylpyridinium, BDP = 1-(3,4-dichlorobenzyl)-3,5-dimethylpyridinium and CP = 1-(2,4-dichlorobenzyl)-3-methylpyridinium) have been prepared and characterized by elemental analysis, IR and single-crystal X-ray diffraction. All the compounds formed stacking columns containing cations and anions. In the crystal structure of 1, both ADP cations and [Ni(dmit)₂] anions were found to form stacked dimers, and these dimers piled up alternately in columns. In 2, the anions of [Ni(dmit)₂] anions stack into dimers, which further construct into a 1D zig-zag chain through lateral S?S interactions. Compound 3 shows stacks built from trimers of Ni(dmit)₂ units, which further construct into 3D network structure through short S···S interactions, S···Cl interactions and C–H?S hydrogen bonds. Magnetic susceptibility measurements for 1–3 in the temperature range 2–300 K show that the overall magnetic behavior indicates the presence of antiferromagnetic interaction, while 3 exhibits an activated magnetic behavior in the high-temperature region (HT) together with a Curie tail in the low-temperature region (LT).     

Synthesis of o-benzoquinones annulated with 2-thioxo-1,3-dithiole-4,5-dithiolate fragment. Dioxolene ligands bearing non-planar geometry

A procedure has been developed for the annulation of a 2-(thi)oxo-1,3-dithiole-4,5-dithiolate fragment to 3,6-di-tert-butyl-o-benzoquinone. The resulting o-quinones have a significant asymmetry with respect to the plane of the chelate dioxolene site, which can be used in the targeted design of the coordination environment of metal ions in complexes. Isomeric manganese adducts containing dioxolene, carbonyl, and phosphine ligands, which differ in the location of the asymmetric o-quinone ligand, have been characterized by EPR spectroscopy.