Zur Koordinationschemie des 1,3-Dithiol-2-selon-4,5-diselenolats (dsise) und des 1,3-Dithiol-2-selon-4,5-dithiolats (dmise). Kristall- und Molekülstruktur des Tetrabutylammonium-bis-(1,3-dithiol-2-selon-4,5-diselenolato)nickelat(II) und -(III), [(n-C4H9)4N]2[Ni(dsise)2] und (n-C4H9)4N[Ni(dsise)2]

Coordination Chemistry of 1,3-Dithiole-2-selone-4,5-diselenolate (dsise) and 1,3-Dithiole-2-selone-4,5-dithiolate (dmise). Crystal and Molecular Structure of Tetrabutylammonium bis(1,3-dithiole-2-selone-4,5-diselenolato)nickelate(II) and -(III), [(n-C₄H₉)₄N]₂[Ni(dsise)₂ and (n-C₄H₉)₄[Ni(dsise)₂] Syntheses and properties of metal(II) and metal(III) bis-chelates of 1,3-dithiole-2-selone-4,5-diselenolate (dsise), of the general type (Bu₄N)_n)M(dsise)₂] (n =2 : M = Zn, Cd, Hg, Cu, Ni, Pd; n = 1: M = Ni, Au) are reported and compared with chelates of the isologue 1,3-dichalcogenole-2-chalcogenoe-4,5-dichalcogenolate (i. r., ¹³C-n. m. r., e. p. r., cyclovoltammetric data). The unexpected rearrangement during the syntheses of dsise and 1,3-dithiole-2-selone-4,5-diselenolate (dmise) is characterized by ab-initio SCF calculations. The x-ray structures of (Bu₄N)₂[Ni(dsise)₂] (space group P2₁/c, a = 8.5556(13) Å, b = 15.0009(12) Å, c = 19.696(3) Å, β = 96.018(7)°, V = 2513.9(5) ų, Z = 2) and Bu₄N[Ni(dsise)₂] (space group C2/c, a = 25.133(6) Å, b = 9.828(4) Å, c = 18.104(7) Å, β = 132.81(1)°, V = 3281(2) ų, Z = 4) are given.     

Zur Koordinationschemie des 1,3-Dithiol-2-thion-4,5-diselenolats (dsit) – ein Vergleich mit 1,3-Dithiol-2-thion-4,5-dithiolat (dmit)

Coordination Chemistry of 1,3-Dithiole-2-thione-4,5-diselenolate (dsit) — Comparison with 1,3-Dithiole-2-thione-4,5-dithiolate (dmit) Synthesis and properties of metal(II) and/or metal(III) bis-chelates of 1,3-dithiole-2-thione-4,5-diselenolate (dsit) of general type (Bu₄N)_n[M(dsit)₂] (n = 2: M ? Zn, Cd, Hg, Cu, Ni, Pd, Pt; n = 1: M ? Ni, Au) are described. By comparison of the ir, ¹³C nmr, epr spectra, cyclovoltammetric data, and x-ray investigations (nickel-bis-chelates) of chelates of dsit and those of the chelates of 1,3-dithiole-2-thione-4,5-dithiolate (dmit) the consequences of selenium for sulfur substitution on position 4 and 5 of the heterocyclic ligand are discussed.     

Synthese und Charakterisierung von Metallocen-Chelaten heterocyclischer 1,2-Dithiolate

Synthesis and Characterization of Metallocene Chelates of Heterocyclic 1,2-Dithiolates Synthesis and properties of metalocene dithiolene chelates Cp₂ML with metal(IV) ions (M) of group IVA (Ti, Zr, Hf) and of vanadium with L = dmit (1,3-dithiole-2-thione-4,5-dithiolate), dmt (1,2-dithiole-3-thione-4,5-dithiolate), dmid (1,3-dithiole-2-one-4,5-dithiolate) and dmise (1,3-dithiole-2-selone-4,5-dithiolate) are described. The structures of these compounds were discussed using IR-, UV/VIS-, ¹H-NMR-, ¹³C-NMR- and EPR data. The activation parameters of the chelate ring inversion of titanocene dithiolenes (Cp₂TiL) and the x-ray structure of Cp₂Ti(dmid) are given.     

Zur Koordinationschemie des 1,3-Thiaselenol-2-thion-4,5-dithiolats (dmits) – ein Vergleich mit 1,3-Dithiol-2-thion-4,5-dithiolat (dmit)

Coordination Chemistry of 1,3-Thiaselenole-2-thione-4,5-dithiolate (dmits) – Comparison with 1,3-Dithiole-2-thione-4,5-dithiolate (dmit) Synthesis and properties of metal(II) and/or metal(III)-bis-chelates of 1,3-thiaselenole-2-thione-4,5-dithiolate (dmits) of the general type (Bu₄N)_n[M(dmits)₂] (n = 2: M = Zn, Cd, Hg, Ni, Cu, Pd; n = 1: M = Au, Ni) are described. By comparison of the i.r., ¹³C-n.m.r., epr spectra and cyclovoltammetric data of chelates of dmits and those of 1,3-dithiole-2-thione-4,5-dithiolate (dmit) the consequences of the substitution of selenium for sulfur on position 3 of the heterocyclic ligand dmit are discussed.     

Synthese und Charakterisierung von Metallocen-Chelaten heterocyclischer 1,2-Diselenolate

Synthesis and Characterization of Metallocene Chelates of Heterocyclic 1,2-Diselenolates Synthesis and properties of metallocen diselenolates Cp₂^RML (Cp^R = η⁵-C₅H₄CH₃ (Cp′); η⁵-C₅(CH₃)₄ C₂H₅ (Cp^o)) of titanium(IV) and vanadium(IV) with L = dsit (1,3-dithiole-2-thione-4,5-diselenolate), dsise (1,3-dithiole-2-selone-4,5-diselenolate) dsitse (1,3-thiaselenole-2-selone-4,5-diselenolate) and dsis (1,3-diselenole-2-selone-4,5-diselenolate) are described. The structures of these compounds in solution are discussed using ¹H, ¹³C, ⁷⁷Se NMR and EPR data. Their voltammetric behaviour is investigated in dichloromethane. The activation parameters of the chelate ring inversion of the titanocene diselenolates (Cp₂^RTiL) and the x-ray structures of Cp₂′Ti(dsit), Cp₂^oTi(dsit); Cp₂^oTi(dsise) (2 modifications) and Cp₂^oTi(dsis) are reported.     

Photooxidation of Transition Metal Complexes of 1,3-Dithiole-2-thione-4,5-dithiolate (dmit) and 1,2-Dithiole-3-thione-4,5-dithiolate (dmt)

Metall(II) bis-chelates of 1,3-dithiole-2-thione-4,5-dithiolate (dmit) and 1,2-dithiole-3-thione-4,5-dithiolate (dmt) undergo in CHCl₃/CH₃CN (ratio 1:24) photooxidation to the metal(III) bis-chelates when irradiated at 313 nm. No side reactions were observed. There is no correlation between the quantum yields of photooxidation and the electrochemical halve-wave potentials. This holds also in comparison to maleonitriledithiolato chelates.     

A series of neutral radical CpNi(dithiolene). complexes

The heteroleptic neutral radical dithiolene complexes CpNi(dmit)., CpNi(dsit). and CpNi(dmid).(dmit=1,3-dithiole-2-thione-4,5-dithiolate; dsit=1,3-dithiole-2-thione-4,5-diselenolate; dmid=1,3-dithiole-2-one-4,5-dithiolate) are obtained from the reaction of (Cp2Ni)BF4 with either (n-Bu4N)[Ni(dmit)2] and (n-Bu4N)[Ni(dmid)2] or PhSb(dmit) and PhSb(dsit), respectively. The three complexes reduce reversibly to the corresponding Ni(II) anions and oxidize reversibly to the cationic state. As deduced from DFT calculations performed on CpNi(dmit)., the SOMO of these complexes is essentially localized on the dithiolene moiety with little metal contribution. CpNi(dsit). is isostructural with CpNi(dmit). and crystallizes in the monoclinic system, space group P2(1). In the solid-state structures of both CpNi(dmit). and CpNi(dsit)., molecules interact through a three-dimensional set of intermolecular interactions mediated by short SS, SeSe and SSe contacts, as confirmed from the temperature and field dependence of the magnetic susceptibility by the observation of an antiferromagnetic ground state below T(Neel)=27 K in CpNi(dmit)., 18 K in CpNi(dsit).. Finally, CpNi(dmid). crystallizes in the orthorhombic system, space group Pnma. Molecules organize into uniform chains through the stacking of the dmid moieties in a sigma-type face-to-face overlap.     

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.     

A New Paramagnetic Pd(dmit)2 Salt: Tris(2,2′-Bipyridine)Nickel(II) Bis(1,3-Dithiole-2-Thione-4,5-Dithiolato)Palladate(II) Mono-Acetonitrile; [Ni(bpy)3][Pd(dmit)2]·CH3CN

Combination of the [Ni(bpy)₃]²⁺ cation complex and the [Pd(dmit)₂]⁻ anion (dmit=C₃S₅²⁻=1,3-dithiole-2thione-4,5-dithiolate) has resulted in the paramagnetic [Ni(bpy)₃][Pd(dmit)₂]·CH₃CN compound, a suitable precursor for a molecular magnetic conductor. Its crystal structure consists of a Pd(dmit)₂ anion arrangement that is quite different from segregated stack layers often found for M(dmit)₂−based compounds. The reduction of the [Pd(dmit)₂]^- to the 2− charged anion in the title compound most probably is the result of a charge disproportionation between Pd(dmit)₂ anions.     

Synthesis and Crystal Structure of 〔EDA〕〔Ni(dmit)_2〕_3

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＮｉ（ｄｍｉｔ）２ｍｏｌｅｃｕｌｅｓｇｉｖｅｒｉｓｅｔｏａｎｕｍｂｅｒｏｆｍｏｌｅｃｕｌａｒｃｏｎｄｕｃｔｏｒｓ〔１，２〕ｉｎａｄｄｉｔｉｏｎｔｏｓｕｐｅｒｃｏｎｄｕｃｔｏｒｓ〔３，４〕．Ｔｈｅｍｕｌｔｙｓｕｌｆｕｒｆ...     

Hydrogen-Bonded Polyrotaxane Cation Structure in Nickel Dithiolate Anion Radical Salts: Ferromagnetic and Semiconducting Behavior Associated with Structural Phase Transition

The pseudo-polyrotaxane structure of [(H-bpy⁺)- (DB-24-crown-8)]_∞ (H-bpy⁺ = monoprotonated 4,4-bipyridinium; DB-24-crown-8 = dibenzo-24-crown-8) has been incorporated into the anion radical salt [Ni(dmit)₂]⁻ (dmit²⁻ = 1,3-dithiole-2-thione-4,5-dithiolate). (H-bpy⁺)(DB-24-crown-8)[Ni(dmit)₂]⁻ crystallized as two polymorphs, crystals 1 and 2 . Crystal 1 was found to have a lower density and looser packing structure in which H-bpy⁺ forms a one-dimensional hydrogen-bonding chain that passes though the crown ether ring of DB-24-crown-8. DB-24-crown-8 adopts a U-shaped conformation in which two phenylene rings sandwich one of the pyridyl rings of H-bpy⁺ to stabilize the structure. The [Ni(dmit)₂]⁻ anions are arranged in a layer parallel to the (10) plane with uniform side-by-side interactions. A structural phase transition was observed at 235 K, accompanied by ordering of the polyrotaxane structure. In crystal 1 , at 173 K, H-bpy⁺ is twisted around the central C−C bond, which perturbs the arrangement of [Ni(dmit)₂]⁻ through short C−H⋅⋅⋅S contacts. As a result, the semiconducting behavior, with an activation energy of 0.21 eV, becomes insulating below 235 K. The crystal exhibits ferromagnetic interactions because of the weak side-by-side interactions between [Ni(dmit)₂]⁻ anions. Crystal 2 has a similar pseudo-polyrotaxane structure but showed no phase transition. This suggests that the looser crystal packing in crystal 1 induces the structural change of the pseudo-polyrotaxane, perturbing the electron system of [Ni(dmit)₂]⁻.     

Synthesis and Structural Characterization of the Complex 〔Et_4N〕_2〔Ni_2(C_2S_4)(C_3S_5)_2〕

１ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｃｈｅｍｉｓｔｒｙｏｆｃｏｍｐｏｕｎｄｓｗｉｔｈｄｍｉｔ（ｄｍｉｔ＝１,３ ｄｉｔｈｉｏｌｅ ２ ｔｈｉｏｎｅ ４,５ ｄｉｔｈｉｏｌａｔｅ）ｈａｓａｔｒａｃｔｅｄｃｏｎｓｉｄｅｒａｂｌｅａｔｅｎｔｉｏｎｒｅｃｅｎｔｌ...     

The decomposition kinetics of [Et4N]2[M(dmit)2] (M = Ni, Pd) in a nitrogen atmosphere using thermogravimetry

Thermal properties and thermal decompositions of [NEt₄]₂[M(dmit)₂] (M = Ni(II), Pd(II), dmit = 1,3-dithiole-2-thione-4,5-dithiolate) have been studied by thermogravimetry (TG). The TG analysis has shown that the complexes are thermally stable up to 460 K and the decomposition of the complexes occurs in three consecutive stages up to 873 K. A thermal stability scale for [M(dmit)₂]ⁿ⁻ anions was based on the thermal properties. Kinetics parameters, such as activation energy, E_a, and kinetic apparent pre-exponential factor, ln A_app, have been calculated from the thermogravimetric data at heating rates of 10, 15, 20 and 25 K/min involving differential (Friedman's equation) and integral (Flynn-Wall-Ozawa's equation) methods.     

Two Polymorphs of (Anilinium)(18-Crown-6)[Ni(dmit)2]: Structure and Magnetic Properties

Two polymorphs of monovalent [Ni(dmit)₂]⁻ (dmit²⁻=2-thioxo-1,3-dithiole-4,5-dithiolate) crystals A and B, (anilinium)(18-crown-6)[Ni(dmit)₂], were prepared, and the structure and magnetic properties were investigated. In these crystals, the [Ni(dmit)₂]⁻ molecules form dimers, which arranged into chains between the supramolecular cation structure (anilinium)(18-crown-6). In crystal A, supramolecular cation formed a regular stack, inducing ladder structure of [Ni(dmit)₂], whose magnetism had been well fitted by spin ladder equation with the spin gap of Δ=190 K. Crystal B is ca. 3% more densely packed compared to crystal A. Due to the dense packing, supramolecular cation stack is distorted, which prevented the intermolecular interaction between [Ni(dmit)₂]⁻ dimers in direction corresponds to the ladder-leg direction in crystal A. Reflecting the [Ni(dmit)₂]⁻ arrangement, crystal B showed a temperature dependence of magnetic susceptibility well reproduced by the singlet-triplet thermal activation model, whose antiferromagnetic exchange interaction (2J) was 140 K.     

Synthesis,X-ray crystal structure and electrochemical properties of (dithiolato)(diimine)copper(II) complexes: [Cu(mnt)(phen)] n and [Cu(dmit)(phen)] 2

Copper (II) complexes [Cu(dmit)(phen)]₂ (1) and [Cu(mnt)(phen)] _n (2) (mnt^2??=?maleonitriledithiolate, dmit^2??=?1,3-dithiole-2-thione-4,5-dithiolate, phen?=?1,10-phenanthroline) have been prepared by ligand-exchange between phen and [N(Bu)₄]₂[Cu(dmit)₂] or [N(Bu)₄]₂[Cu(mnt)₂]. Both complexes have been characterized by spectroscopic, electrochemical, and single-crystal X-ray analysis. In complex 1, dimers are extended into a two-dimensional array by weak S5–Cu contacts. In complex 2, monomers are extended into chains in a head-to-tail arrangement by weak Cu–S coordination bonds and π–π stacking interactions.     

Two pressure-induced superconducting anion radical salts exhibiting different spin states at ambient pressure

Pressure-induced superconducting behavior was found in two anion radical salts, EtMe3Z[Pd(dmit)2]2 (dmit = 1,3-dithiole-2-thione-4,5-dithiolate, Z = P, As), that are Mott insulators and exhibit different magnetic and structural transitions at ambient pressure.     

Ni(dmit)2 salts with chiral stilbazolium- and ferrocenyl-based chromophores as countercations

Four 1:1, two-component salts combining the [Ni(dmit)₂]⁻ anion (dmit²⁻ = 2-thioxo-1,3-dithiole-4,5-dithiolato) and chiral stilbazolium-based countercations (HPMS⁺ = 4′-[2-(hydroxymethyl)pyrrolidinyl]-1-methylstilbazolium and MPMS⁺ = 4′-[2-(methoxy-methyl)pyrrolidinyl]-1-methylstilbazolium), or chiral ferrocenyl-based countercations (2⁺ = (E)-1-((R)-2-methylferrocenyl)-2-(1-methyl-4-pyridiniumyl)ethene; 3⁺ = (E)-1-((S)-2-trimethylsilylferrocenyl)-2-(1-methyl-4-pyridiniumyl)ethene) were prepared. Semiconducting behaviour (2·10⁻⁴ S·cm⁻¹ measured on compressed pellets for [Ni(dmit)₂] (MPMS), for example) is secured by the presence of the [Ni(dmit)₂]⁻ anions. The chiral nature of the countercations ensures non-centrosymmetry of the structures (space group P1 for [Ni(dmit)₂](2) and [Ni(dmit)₂](3), for example). A ubiquitous antiparallel arrangement of the cations, which are thus packed in a pseudo-centrosymmetrical environment, results in almost vanishing second-order susceptibilities χ⁽²⁾, and therefore zero efficiencies in second harmonic generation.     

A family of oxo-chalcogenide molybdenum and tungsten complexes, (n-Bu4N)2[M2O2(mu-Q)2(1,3-dithiole-2-thione-4,5-dithiolate)2] (M = Mo, W; Q = S, Se): new synthetic entries, structure, and gas-phase behavior

A new series of complexes with the general formula (n-Bu4N)2[M2O2(micro-Q)2(dmit)2] (where M = Mo, W; Q = S, Se; dmit = 1,3-dithiole-2-thione-4,5-dithiolate) have been prepared. Fragmentation of the trinuclear cluster (n-Bu4N)2[Mo3(micro3-S)(micro-S2)3(dmit)3] in the presence of triphenylphosphine (PPh3) gives the dinuclear compound (n-Bu4N)2[Mo2O2(micro-S)2(dmit)2] [(n-Bu4N)2[2]], which is formed via oxidation in air from the intermediate (n-Bu4N)2[Mo3(micro3-S)(micro-S)3(dmit)3] [(n-Bu4N)2[1]] complex. Ligand substitution of the molybdenum sulfur bridged [Mo2O2(micro-S)2(dimethylformamide)6]2+ dimer with the sodium salt of the dmit dithiolate also affords the dianionic compound (n-Bu4N)2[2]. The whole series, (n-Bu4N)2[Mo2O2(micro-Se)2(dmit)2] [(n-Bu4N)2[3]], (n-Bu4N)2[W2O2(micro-S)2(dmit)2] [(n-Bu4N)2[4]], (n-Bu4N)2[W2O2(micro-Se)2(dmit)2] [(n-Bu4N)2[5]], and (n-Bu4N)2[Mo2O2(micro-S)2(dmid)2] [(n-Bu4N)2[6]; dmid = 1,3-dithiole-2-one-4,5-dithiolate], has been synthesized by the excision of the polymeric (Mo3Q7Br4)x phases with PPh3 or 1,2-bis(diphenylphosphanyl)ethane in acetonitrile followed by the dithiolene incorporation and further degradation in air. Direct evidence of the presence of the intermediates with the formula [M3Q4(dmit)3]2- (M = Mo, W; Q = S, Se) has been obtained by electrospray ionization mass spectrometry. The crystal structures of (n-Bu4N)2[1], (PPh4)2[Mo2O2(micro-S)2(dmit)2] [(PPh4)2[2]; PPh4 = tetraphenylphosphonium], (n-Bu4N)2[2], (n-Bu4N)2[4], (PPh4)2[W2O2(micro-Se)2(dmit)2] [(PPh4)2[5]], and (n-Bu4N)2[6] have been determined. A detailed study of the gas-phase behavior for compounds (n-Bu4N)2[2-6] shows an identical fragmentation pathway for the whole family that consists of a partial breaking of the two dithiolene ligands followed by the dissociation of the dinuclear cluster.     

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).     

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.