Supramolecular rotor: adamantylammonium([18]crown-6) in [Ni(dmit)2]- salt

Adamantylammonium (ADNH3+) was complexed with [18]crown-6, forming a supramolecular cation of (ADNH3+)([18]crown6), which was introduced into a [Ni(dmit)2]- salt as a supramolecular rotor. The cation layers were alternately arranged with [Ni(dmit)2]- layers in the crystal, in which the molecular rotation of (ADNH3+)([18]crown-6) was confirmed from the temperature-dependent solid-state 1H NMR.     

Structural phase transition of magnetic [Ni(dmit)2]- salts induced by supramolecular cation structures of (M+)([12]crown-4)2

Sandwich-type supramolecular cation structures of (M(+))([12]crown-4)(2) complexes (M(+) = Li(+), Na(+), K(+), and Rb(+)) were introduced as countercations to the [Ni(dmit)(2)](-) anion, which bears an S = (1)/(2) spin, to form novel magnetic crystals (dmit(2-) = 2-thione-1,3-dithiole-4,5-dithiolate). The zigzag arrangement of Li(+)([12]crown-4)(2) cations in Li(+)([12]crown-4)(2)[Ni(dmit)(2)](-) salt induced weak intermolecular interactions of [Ni(dmit)(2)](-) dimers, whose magnetic spins were isolated from each other. The molecular arrangements of cations and anions in M(+)([12]crown-4)(2)[Ni(dmit)(2)](-) salts (M(+) = Na(+), K(+), and Rb(+)) were isostructural to each other. In the case of Na(+)([12]crown-4)(2)[Ni(dmit)(2)](-), the space group C2/m changed to C2/c with a lowering in temperature from 298 to 100 K. This structural change occurred at 222.5 K as a first-order phase transition. The space group C2/m (T = 298 K) in the salt K(+)([12]crown-4)(2)[Ni(dmit)(2)](-) also changed to C2/c (T = 100 K), which transition occurred at 270 K. Crystal structural analyses at 298 and 100 K revealed changes in both supramolecular cation conformation and [Ni(dmit)(2)](-) anion arrangements. The transition from C2/m to C2/c crystals generated a dipole moment in the Na(+)([12]crown-4)(2) and K(+)([12]crown-4)(2) structures, which were reconstructed to cancel the net dipole moment of the C2/c crystals. These cation transformations led to changes in intermolecular interactions between the [Ni(dmit)(2)](-) anions via structural rearrangements. The crystal structure of C2/c was stabilized in Rb(+)([12]crown-4)(2)[Ni(dmit)(2)](-) at 298 K. The [Ni(dmit)(2)](-) configuration in these salts with the C2/c space group was a one-dimensional uniform chain, which showed the temperature-dependent magnetic susceptibility of a one-dimensional linear Heisenberg antiferromagnetic chain.     

1,2-Dialkoxyacenaphthylenes and 2,3,11,12-bis-(1,2-acenaphtho)-[18]crown-6

A general synthesis of 1,2-dialkoxyacenaphthylenes by dehydrogenation of the corresponding acenaphthene derivatives with high potential quinones is described. The new crown ether, 2,3,11,12-bis(1,2-acenaphtho)-[18]crown-6, 1, is obtained by this route. The surprisingly poor complexing ability of 1 is ascribed to electronic and geometrical effects of the acenaphthylene rings as shown by spectroscopic and voltammetric data and the crystal structure of the free ligand 1.     

Molecular rotor of Cs2([18]crown-6)3 in the solid state coupled with the magnetism of [Ni(dmit)2

Nanoscale molecular rotors that can be driven in the solid state have been realized in Cs2([18]crown-6)3[Ni(dmit)2]2 crystals. To provide interactions between the molecular motion of the rotor and the electronic system, [Ni(dmit)2]- ions, which bear one S=1/2 spin on each molecule, were introduced into the crystal. Rotation of the [18]crown-6 molecules within a Cs2([18]crown-6)3 supramolecule above 220 K was confirmed using X-ray diffraction, NMR, and specific heat measurements. Strong correlations were observed between the magnetic behavior of the [Ni(dmit)2]- ions and molecular rotation. Furthermore, braking of the molecular rotation within the crystal was achieved by the application of hydrostatic pressure.     

Towards Single-component Molecular Conductor [Ni（dmit）2 ] by Charge Disproportionation： 2[Ni（dmit）2]^0.5→[Ni（dmit）2 ]＋ [Ni（dmit）2]^-

A new method of synthesizing single-component molecular conductor [Ni(dmit)2] bythe reaction 2(Me4N)[Ni(dmit)2]2→ [Ni(dmit)2] (Me4N)[Ni(dmit)2] is reported. [Ni(dmit)2]exhibits a semiconductive behavior above 167 K, while from 167 K down to the measuring limit of 60 K, it exhibits metallic conductivity.     

Supramolecular cations of the m-fluoroanilinium(dibenzo[18]crown-6) in ferromagnetic salt

A supramolecular cation of (m-FAni(+))(DB[18]crown-6), where m-FAni(+) and DB[18]crown-6 denote m-fluoroanilinium(+) and dibenzo[18]crown-6, respectively, which is the polar unit rotating in the ferroelectric crystal of (m-FAni(+))(DB[18]crown-6)[Ni(dmit)(2)](-), was introduced into a ferromagnetic [MnCr(oxalate)(3)](-) salt as the counter cation. The crystal structure of (m-FAni(+))(DB[18]crown-6)[MnCr(oxalate)(3)](-)(CH(3)OH)(CH(3)CN) (1) is constructed from alternating layers of a two-dimensional honeycomb layer of [MnCr(oxalate)(3)](-) and (m-FAni(+))(DB[18]crown-6) supramolecular cations. The anionic layer is composed of Mn(II) and Cr(III) ions with S = 5/2 and S = 3/2 spins, respectively, bridged by the oxalate anions, which show ferromagnetic ordering at 5.5 K. The supramolecular structure is formed through the formation of hydrogen bonds between the ammonium hydrogen atoms of the m-FAni(+) cations and the oxygen atoms of the DB[18]crown-6 cavity. No orientational disorder of the fluorine atoms was observed in our X-ray structural analysis, suggesting that a two-fold flip-flop motion of the m-FAni(+) cations does not occur in the salt. The rotational freedom of the m-FAni(+) cations in the salt is restricted by the steric hindrance from neighbouring DB[18]crown-6 molecules. A design strategy for the rotation in a salt is discussed, based on the volume that the supramolecular cations occupy in the unit cell.     

Towards Single-component Molecular Conductor [Ni(dmit)_2] by Charge Disproportionation:2[Ni(dmit)_2]~(-0.5)[Ni(dmit)_2]+[Ni(dmit)_2]~-

It was commonly thought that a molecular conductor or semiconductor should be composed of at least two components to make the conducting component in partially charged state. However, this idea became questionable by the recent report of the single-component molecular conductor [Ni(tmdt)2]1 as well as several reports about single-component molecular semiconductors such as [Ni(ptdt)2]2 and [Ni(C10H10S8)2]3. In fact, as early as 1985, [Ni(dmit)2] as a by-product in synthesizing TTF[Ni(dmit…     

Crystal structure and magnetic properties of Gd2([18]crown-6)2(OH)2(CH3CN)2[Ni(dmit)2]4 complex having f- and pi-spins

Crystal structure and magnetic properties of Gd(2)([18]crown-6)(2)(OH)(2)(CH(3)CN)(2)[Ni(dmit)(2)](2) (dmit(2)(-) = 2-thioxo-1,3-dithiole-4,5-dithiolate) are reported. Gd(3+) ions (S = (7)/(2)) were introduced into the pi-spin network of [Ni(dmit)(2)](-) (S = (1)/(2)) complex as a binuclear supramolecular cation, Gd(2)([18]crown-6)(2)(OH)(2)(CH(3)CN)(2), in which two Gd([18]crown-6) units are bridged with two hydroxide ions. The weak antiferromagnetic interactions between Gd.Gd through hydroxide ions were observed, and [Ni(dmit)(2)](-) formed isolated monomers and dimers in the crystal.     

Cooperativity of dynamics of 18-crown-6 molecule forming one-dimensional chain in Cs2(18-crown-6)3[Ni(dmit)2]2

Heat capacity of Cs2(18-crown-6)3[Ni(dmit)2]2 was measured by adiabatic calorimetry. A broad thermal anomaly was observed around 225 K. The entropy gain (about 52 J K(-1) mol(-1)) is much larger than that expected for twofold disordering of 18-crown-6 assumed in the previous structure analysis. The shape of thermal anomaly was qualitatively explained by a linear Ising model developed for cooperative disordering in polymers. The 18-crown-6 molecules forming a one-dimensional chain in the crystal are orientationally disordered with moderate cooperativity.     

弱相互作用构筑的二维、三维冠醚配合物{[K(18-C-6)2(C2H4Cl2)}[Ni(dmit)2]2和[K(18-C-6)][Ni(dmit)2]的合成与结构

研究了18－冠－6与NiCl·6H2O,K2dmit(dmit=4,5-dimercapto-1,3-dithiole- 2-thione,C3S5^2－）在不同溶剂中反应生成的两个标题配合物{[K(18-C-6)]2 (C2H4Cl2)}[Ni(dmit)2]2（1）和[K(18-C-6)][Ni(dmit)2](2)。通过元素分析、红 外光谱、单晶X射线衍射进行了表征。1和2均属三斜晶系,空间群P1^-.1的晶体学 数据：a=1.0272(2)nm,b=1.2282(3)nm,c=1.4205(3)nm,α=113.473(3)°,β=90. 609(3)°,γ=91.439(3)°,V=1.6430(6)nm^3,Z=2,F（000)=876,R1=0.0503。2的 晶体学数据：a=0.8502(2)nm,b=1.2178(4)nm,c=1.5118(4)nm,α=86.454(5)°,β =77.734(5)°,γ=85.364(5)°,V=1.5228(8)nm^3,Z=2,F(000)=774,R1=0.0565。配 合物1,2分别通过K…S,K…Cl,S…S和K…S,S…S弱相互作用形成二维、三维网状 结构。     

Irreversible Structural Phase Transition in [(9-triptycylammonium) ([18]crown-6)][Ni(dmit)2]: Origin and Effects on Electrical and Magnetic Properties

Materials exhibiting irreversible phase transitions, leading to changes in their properties, have a potential for novel application in electronic components such as a non-rewritable high-security memory. Here, we focused on the two salts, [(9-triptycylammonium)([18]crown-6)][Ni(dmit)₂] ( 1 ) and [(9-triptycylammonium)([15]crown-5)][Ni(dmit)₂] ( 2 ), which featured 2D sheet structures with alternately stacked cation and anion layers. Both salts exhibit similar cation arrangements, however, their anion arrangements differ significantly. The temperature-dependent magnetic susceptibilities of 1 and 2 were well reproduced by the alternating chain model (J_AC1/k_B=−306(8), J_AC2/k_B=−239(3) K) and the Curie-Weiss model (θ=−3.9(1) K), respectively. 1 experience a reversible phase transition around 40–60 K, causing anomalies in magnetic behavior. Moreover, an irreversible single-crystal-to-single-crystal phase transition to 1′ undergo at ~381 K, inducing a rearrangement of [Ni(dmit)₂]⁻ anions and a resistivity decrease from 6.5×10⁶ to 6.5×10² Ω cm. The susceptibility curve of 1′ was reproduced by a combination of the Curie-Weiss and dimer models (J_dimer/k_B=−407(5), θ=−26.7(5) K). The irreversible transition of 1 is the first example for such supramolecule and [Ni(dmit)₂]⁻ system to our knowledge, in opening potential new-type materials.     

Double complex salts [Ni(NH3)6]3[Fe(CN)6]2 and [Ni(NH3)6]3[Cr(CNS)6]2: Synthesis and properties

The double complex salts [Ni(NH₃)₆]₃[Fe(CN)₆]₂ and [Ni(NH₃)₆]₃[Cr(CNS)₆]₂ were synthesized and their thermal decomposition in air was studied. The values of interplanar distances in crystal lattices were determined. The compounds are proposed as precursors for producing homogeneous bimetallic nanodimensional powders.     

Synthesen und Kristallstrukturen der chalkogenidoverbrückten Nickelclusterverbindungen [Ni5Se4Cl2(PPhEt2)6], [Ni12Se12(PnPr3)6] und [Ni18S18(PiPr3)6]

Syntheses and Crystal Structures of Chalcogenido‐bridged Nickel Cluster Compounds [Ni₅Se₄Cl₂(PPhEt₂)₆], [Ni₁₂Se₁₂(PⁿPr₃)₆], and [Ni₁₈S₁₈(PⁱPr₃)₆] The reaction of (R)ESiMe₃ (R = SiMe₃, Mes = C₉H₁₁; E = S, Se) with [NiCl₂(PPhEt₂)₂] and [NiCl₂(PR₃)₂] (R = ⁿPr, ⁱPr) gives new chalcogenido‐bridged nickel cluster compounds [Ni₅Se₄Cl₂(PPhEt₂)₆]·2THF ( 1 ), [Ni₁₂Se₁₂(PⁿPr₃)₆]·2THF ( 2 ), and [Ni₁₈S₁₈(PⁱPr₃)₆]·2THF ( 3 ). The structures of these compounds were determined by single crystal X‐ray structural analyses.     

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.     

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

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Molecular paramagnetic semiconductor: crystal structures and magnetic and conducting properties of the Ni(dmit)(2) salts of 6-oxoverdazyl radical cations (dmit = 1,3-dithiol-2-thione-4,5-dithiolate)

Four kinds of 1:1 and 1:3 salts of 3-[4-(trimethylammonio)phenyl]-1,5-diphenyl-6-oxoverdazyl radical cation ([1](+)) and its mono- and dimethyl derivatives ([2](+) and [3](+)) with Ni(dmit)(2) anions (dmit = 1,3-dithiol-2-thione-4,5-dithiolate) ([1](+)[Ni(dmit)(2)](-) (4), [2](+)[Ni(dmit)(2)](-) (5), [3](+)[Ni(dmit)(2)](-) (6), and [1](+)[Ni(dmit)(2)](3)(-) (7)) have been prepared, and the magnetic susceptibilities (chi(M)) have been measured between 1.8 and 300 K. The chi(M) values of salts 5 and 7 can be well reproduced by the sum of the contributions from (i). a Curie-Weiss system with a Curie constant of 0.376 (K emu)/mol and negative Weiss constants (THETAV;) of -0.4 and -1.7 K and (ii). a dimer system with strong negative exchange interactions of 2J/k(B) = -354 and -258 K, respectively. The dimer formations in Ni(dmit)(2) anions have been ascertained by the crystal structure analyses of salts 4-6. In salts 4 and 6, Ni(dmit)(2) dimer molecules are sandwiched between two verdazyl cations, indicating the formation of a linear tetramer in 4 and 6. The magnetic susceptibility data for salts 4 and 6 have been fitted to a linear tetramer model using an end exchange interaction of 2J(1)/k(B) = -600 K and a central interaction of 2J(2)/k(B) = -280 K for 4 and 2J(1)/k(B) = -30 K and 2J(2)/k(B) = -580 K for 6, respectively. The results of the temperature dependence of the g(T) value in salts 4-6 obtained by ESR measurement also support the above analyses. The 1:1 salts 4-6 are insulators. On the other hand, the conductivity of the 1:3 salt 7 at 20 degrees C was sigma = 0.10 S cm(-)(1) with an activation energy E(A) = 0.099 eV, showing the semiconductor property. Salt 7 is a new molecular paramagnetic semiconductor.