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The proton conduction of {NBu2(CH2COOH)2}[MnCr(ox)3] (dic-MnCr) is studied in comparison with its analogous {NBu3(CH2COOH)}[MnCr(ox)3] (moc-MnCr). The proton conductivity is enhanced remarkably by the multiplication of the carboxyl carrier in the cation, from 5.2 × 10-7 S cm-1 at 90% RH (25 °C) in moc-MnCr to 1.8 × 10-3 S cm-1 at 95% RH (25 °C) in dic-MnCr.

Single crystals of three neutral charge-transfer complexes and a cation radical salt based on a C2v-symmetric polycyclic aromatic hydrocarbon, benzo[ghi]perylene (bper), were obtained. The 1 : 1 complex with 7,7,8,8-tetracyanoquinodimethane (TCNQ) involves DA-type alternating π-columns, whereas the alternating π-columns in the 2 : 1 TCNQ complex are flanked by another bper molecule. The in-plane rotation of bper in the 1 : 1 complex was significantly suppressed compared with that of coronene in (coronene) (TCNQ), which is associated with the lower molecular symmetry of bper. Whereas the 3 : 1 TCNQ complex involves DDA-type alternating π-columns flanked by another bper molecule, bper molecules in the 3 : 1 cation radical salt with Mo6O192− have a columnar structure with a [101]-like charge-ordered pattern associated with intermolecular interactions in the bay region of bper. The dimerisation of charge-rich bper molecules results in an increased energy gap at the Fermi level, and consequently, semiconducting behaviour of the salt has a larger activation energy than that of the isostructural coronene salt in the partially charged state. The lower molecular symmetry of bper also affects the degeneracy of the frontier-orbitals; the energy difference between the HOMO and the HOMO−1 of bper is significantly larger than that of coronene, which is comparable to the intermolecular transfer integrals.

A 2 : 1 hydrogen-bonded crystal of 2-pyrrolidone and chloranilic acid shows structural phase transitions accompanied by the drastic rearrangement of hydrogen-bonded tapes. Such a phenomenon is attributed to the selective and directional character of hydrogen bonds.

Single crystals of racemic charge-transfer complexes comprising a helical polycyclic aromatic hydrocarbon molecule, [6]helicene, as the electron donor (D) and 7,7,8,8-tetracyano-p-quinodimethane (TCNQ) analogs as the electron acceptor (A) were obtained via either co-sublimation or solvent evaporation. All complexes consist of heterochiral DA-type alternating π-columns with a [⋯(P)-[6]helicene⋯TCNQ⋯(M)-[6]helicene⋯TCNQ⋯] repeating unit, which show a peculiar wavy feature primarily related to the nonplanar geometry of the [6]helicene molecules. [6]Helicene molecules form a two-dimensional sheet intersecting the columns, and the molecular arrangement (namely, either homochiral or heterochiral arrangement) in the sheets depends on the TCNQ analog. Theoretical calculations were carried out to discuss the origin of the molecular deformation of [6]helicene molecules in the CT solids in terms of intermolecular interactions.

The existence of a spin-disordered quantum state was predicted theoretically by Wannier in 1950 and Anderson in 1973. Various target materials had been considered before the discovery of the first quantum spin liquid (QSL) system in 2003: a Mott insulator κ-(ET)2Cu2(CN)3, where ET is bis(ethylenedithio)tetrathiafulvalene. The family of dimer-type ET conductors κ-(ET)2X (where X = an anion) exhibits various conduction profiles ranging from insulators to metals to superconductors depending on the counter anion. In κ-(ET)2X, the anion molecules form characteristic patterns of anion openings, on each of which an ET dimer corresponding to a single spin site is positioned, namely a key–keyhole relation. The topological consideration of the crystal structure affords the information on both a spin geometry (t′/t) and electron correlation (U/W), where t and t′ are interdimer transfer interactions with an isosceles triangular geometry, and U and W are the on-site Coulomb repulsion energy and bandwidth, respectively. The QSL system κ-(ET)2Cu2(CN)3 is characterized by a spin lattice containing nearly equilateral triangles (t′/t = 1.09) with strong electron correlations (U/W = 0.93) at room temperature. The temperature dependences of t′/t and U/W are bases to understand the transport and magnetic behaviors of κ-(ET)2X. κ-(ET)2Cu2(CN)3 has a superconducting state next to the QSL state under pressure without passing through an antiferromagnetic state. Here, the design of QSL systems next to a superconducting state is discussed based on the crystal and the electronic structures and physical properties of κ-(ET)2X using the key–keyhole relation and temperature variant band parameters t, t′, U, and W.

By using a stronger electron acceptor 1,2-dicyano[60]fullerene (C60(CN)2), a donor-acceptor type ionic complex (Bz2Cr˙+)[C60(CN)2˙¬] (1) (Bz2Cr = bis(benzene)chromium), and two anionic salts, K+[C60(CN)2˙¬](THF)x (2) and [K+(DB18C6)(THF)x]2[C60(CN)22¬] (3) (DB18C6 = dibenzo-18-crown-6 ether), were prepared. The charge on the C60(CN)2 molecules in 1 was determined by comparison of the Raman spectrum with those of the potassium salts 2 and 3. An EPR spectrum of 2 showed a narrow Lorentzian-shaped signal with a slightly larger g factor (ΔHpp = 2.8 Oe at g = 1.9997) than that of the C60˙¬ salt K+(C60˙¬)(THF) (ΔHpp = 19 Oe at g = 1.9987), indicating the elimination of the low-lying excited state and thereby the reduction of spin–orbit coupling. For the solid 1, an EPR signal characteristic of Bz2Cr˙+ spin was observed down to 4 K, while no signals arising from C60(CN)2˙¬ spin were seen at any of the temperatures measured. Moreover, the static susceptibility of 1 can be explained in terms of only the paramagnetic spin on the Bz2Cr˙+ cations. The formation of covalently linked [C60(CN)2]22¬ dimers of 1 is proposed to account for this novel phenomena.

A shape deformable nanocomposite composed of MnO2 nanosheets was obtained by a room-temperature one-pot process, namely the graft polymerization of trimethoxysilyl-containing quaternary ammonium cations onto the negatively charged MnO2 nanosheets in aqueous solution. Water network formed near the acidic MnO2 slabs allows the Grotthuss-like proton conduction.

Graft polymerization of trimethoxysilyl-containing ammonium cations on negatively-charged titania nanosheets gives a photoluminescent viscoelastic nanocomposite. Proton conduction network comprised of adsorbed water molecules near the titania slabs leads to the multiple conductometric sensitivities to temperature, humidity, and photo-irradiation.

Two mono-substituted EDO-TTF derivatives, 4,5-ethylenedioxy-4′-methyl-TTF (MeEDO-TTF, 2) and 4,5-ethylenedioxy-4′-methylthio-TTF (MeSEDO-TTF, 3), were synthesized in the moderate yields. These two donors showed similar electronic structures of the π-electron systems to that of the parent molecule EDO-TTF, according to the cyclic voltammetry and UV-vis spectroscopy. Despite their different compositions, the radical cation salts of these two donors exhibited similar optical spectra with a low-lying absorption band at around 3.3 × 103 cm−1, which was consistent with their good conductivities at room temperature. The transport properties of these salts ranged from stable metals, metal–insulator transition systems, to semiconductors. Most of the radical cation salts showed Pauli paramagnetic behavior at around room temperature. The crystal structures of the stable metallic salts, (MeEDO-TTF)2X (X = BF4, ClO4), exhibited a novel donor packing pattern, and the calculated band structures showed two-dimensional feature, consistent with their transport properties.

Room-temperature ionic liquids containing dicyanoaurate(I) anions were prepared utilizing 1-alkyl-3-methylimidazolium cations, and display luminescence possibly due to the oligomerization of the significant fraction of Au(CN)2 anions in the liquids.

The capillary rise method is used to measure the room temperature surface tension of several ionic liquids, selected mainly for their high electrical conductivity. They include salts based on the cations 1-ethyl-3-methylimidazolium (EMI+), 1-butyl-3-methylimidazolium (BMI+), and 1,3-dimethylimidazolium (DMI+), paired with anions such as GaCl4−, FeCl4−, C(CN)3−, N(CN)2−, SCN−, EtSO4−, BF4−, CF3SO3−, (CF3SO3)2N− (Tf2N−) and Au(CN)2−. The method consumes relatively little sample (

A series of paramagnetic ionic liquids, which are comprised of 1-alkyl-3-methylimidazolium RMI+ cation (R = Et, n-Bu, n-hexyl and n-octyl) and tetrahalogenoferrate(III) FeX4− anion (X = Cl and Br), were prepared, and the influence of structural variations such as changing the alkyl chain (R) length in the cation and substituting the halides (X) in the anion on their thermal behavior, infrared and ultraviolet-visible absorption spectra, density, viscosity, ionic conductivity and magnetic susceptibility was characterized. The elongation of the alkyl chain leads to a pronounced reduction of fluidity and ionic conductivity, and the replacement of chlorides with bromides likewise leads to a similar tendency toward ionic diffusion. It would seem that the ion association is less pronounced in the FeBr4 salts, which can be rationalized on the basis of the more significant nephelauxetic effect together with the lower molar concentration in the FeBr4 salts.

Synthesis, crystal structures, electrochemical and physical properties of the new ligand, EDO-EDT-TTF-py (L1) [4,5-ethylenedioxy-4′,5′-(4-pyridylethylenedithio)tetrathiafulvalene], and the paramagnetic transition metal coordination complexes, M(hfac)2(EDO-EDT-TTF-py)2; M = CuII (2), MnII (3), and CuII(hfac)2(EDO-EDT-TTF-py) (4) are reported where hfac = hexafluoroacetylacetonato. Crystal data: (L1) triclinic system, space group P, a = 8.4060(3), b = 10.5093(3), c = 11.5318(5) A, α = 64.758(2), β = 86.923(2), γ = 72.444(2)°, V = 875.22(6) A3, Z = 2, 2 and 3 are isostructural (data for 3 are given in brackets), triclinic system, space group P, a = 7.1085(4) [7.1013(9)A], b = 11.1210(7) [11.111(2)A], c = 16.3628(11) A [16.346(3) A], α = 91.682(2) [91.662(6)], β = 91.014(3) [91.036(7)], γ = 93.547(3)° [93.651(6)°], V = 1290.3(1) A3 [1286.3(3) A3], Z = 1, (4) triclinic system, space group P, a = 9.2937(1), b = 15.1897(2), c = 24.3174(6) A, α = 92.461(1), β = 93.048(1), γ = 105.491(1)°, V = 3297.6(1) A3, Z = 4. In the compounds 2, 3 and 4, the ligand L1 is coordinated to the transition metals through the nitrogen atom of the pyridine group. In the crystal, the organic and inorganic layers are segregated. The arrangement of the organic layers is similar to the well known β phase in BEDT-TTF [bis(ethylenedithio)tetrathiafulvalene] charge transfer complexes, showing that the crystal packing is mainly governed by π–π stacking of the organic molecules. L1 is a TTF derivative and shows the electron donating ability with oxidation potential E1½ = +0.52 V versus SCE in benzonitrile. The same oxidation potentials were observed for complexes 2 and 3, indicating the negligible interactions between the ligands and the metals in solution.

Quinoline-5,8-dione 5 reacted with 1-methylpyrrole in acetic acid to give 6- and 7-(1-methylpyrrol-2-yl)quinoline-5,8-diones, one of which (6-isomer) showed remarkable metallochromic behaviour. Selective synthesis of the 6-isomer from 5 was achieved by addition of metal salts.