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The charge-transfer complex between naphthaceno[5,6-cd:11,12-c′d′]bis[1,2]diselenole (TSeN) and 4,8-bis(dicyanomethylene)-4H,8H-benzo[1,2-c:4,5-c′]bis[1,2,5]thiadiazole (BTDA-TCNQ) is found to show at least three different types of crystal modifications; insulating Type-I has a (1 : 1 : 1) ratio containing solvent molecules (chlorobenzene), metallic Type-II has a (1 : 1) stoichiometry, and semiconductive Type-III is conjectured to have a (1 : 2) or (2 : 1) stoichiometry. The crystal structures of Type-I and Type-II were determined by a single-crystal X-ray diffraction method. Type-I comprises mixed-stack molecular columns, and Type-II segregated-stack molecular columns. In both types the neighboring columns are linked along short molecular axes by two Se···N contacts that are shorter than the corresponding van der Waals contact. In the Type-II crystal, there are other short distances between TSeN and BTDA-TCNQ in the direction of the long molecular axes. From the C=C bond length in the C=C(CN)2 group of B...

Radical salts of 2,7-bis(methylthio)-1,6-dithiapyrene (MTDTPY) with PF6− and 2,7-bis(methylseleno)-1,6-dithiapyrene (MSDTPY) with AsF6− and [Au(CN)2]− were prepared using an electrochemical method. The crystal structures of these salts were determined with an X-ray method. MTDTPY–(PF6)0.67 (triclinic P\bar1) and MSDTPY–(AsF6)0.67 (triclinic P\bar1) form uniform segregated stacks of MTDTPY and MSDTPY molecules with interplanar distances of 3.40 and 3.59 A, respectively. Short S–S contacts of 3.46–3.56 A for MTDTPY–(PF6)0.67 and 3.54–3.61 A for MSDTPY–(AsF6)0.67 were observed between the columns. The chains of disordered PF6− and AsF6− were found to be parallel to the stack axis. Analysis of the disorder showed a stoichiometric ratio of the DTPY derivatives and counter anions at 1:0.67; the formal charge of MTDTPY and MSDTPY was estimated at +0.67. MSDTPY–Au(CN)2 (monoclinic P2/c) forms a segregated stack of MSDTPY molecules with an interplanar distance of 3.40 A. The optical reflection spectra of these cry...

Polarized reflection spectra were measured on two charge-transfer complexes of 2,7-bis(methylthio)-1,6-dithiapyrene (MTDTPY) with chloranil and 7,7,8,8-tetracyanoquinodimethane (TCNQ), which showed metallic conductivity. In spite of short intercolumnar S–S contacts, the spectra showed a strong one-dimensional character. The optical conductivity spectra, σ(ω), and real part of the dielectric constant, e′(ω), along the stack axis were obtained by means of Kramers–Kronig transformation. The conductivity spectra and the dielectric constant of both complexes substantially differ from the simple Drude model. These results were analyzed with a one-dimensional electron localization model in a disordered system with the optical parameters: ωp=13500 cm−1, τi=1.6×10−15s (τi−1=3300 cm−1) for chloranil complex and ωp=12000 cm−1, τi=2.5×10−15s (τi−1=2100 cm−1) for TCNQ complex.

The charge-transfer complex of 2,7-bis(methylthio)-1,6-dithiapyrene (MTDTPY) with tetracyano-2,6-naphthoquinodimethane (TNAP) showed an alternated stacking mode of crystal structure. There are no short intermolecular contacts. The ionicity was estimated to be neutral based on an analysis of the IR stretching frequency of the CN groups and the transition energy of the charge-transfer band.

The crystal of (BEDT-TTF)4[Ni(CN)4] (BEDT-TTF: bis(ethylenedithio)tetrathiafulvalene) belongs to the triclinic P\bar1 with the lattice constants of a=10.994(2), b=16.443(2), c=9.703(1) A, α=97.85(1), β=115.15(1), γ=95.94(1)°. In the crystal, there exists the face to face overlap of the BEDT-TTF molecules along the [201] direction. The intermolecular interaction by the short S···S contact is also observed along the [\bar201] direction.

Single crystals of a (tetrabenzoporphyrinato)nickel hexafluoroarsenate, (NiTBP)3(AsF6)2 were prepared by the use of an electrochemical technique. NiTBP is stacked one-dimensionally with a periodic unit composed of three macrocycles. This stacking mode is a new type among the one-dimensionally stacked macrocyclic complexes. The experimental results on reflectance spectrum and ESR indicate that this material is a one-dimensional semiconductor with a small electron correlation.

New conducting salts of (phthalocyaninato)platinum (PtPc), PtPc(ClO4)0.5 and PtPc(AsF6)x, were prepared by electrochemical oxidation. A crystal of PtPc(ClO4)0.5 belongs to a tetragonal system with a space group of P4⁄mcc, the lattice constants being a=14.062(1) A, c=6.510(1) A, and Z=2. They are metallic at least down to 120 K, the room-temperature conductivity being σ=102–103 S cm−1. XPS indicates that the conduction pathway is located mainly at the ligand chain due to a partial oxidation of the ligand-centered HOMO. ESR experiments have also strongly supported this conclusion. The bandwidth of the ligand-centered conduction band has been estimated to be 1.2 eV from the plasma frequency, hωp=0.87 eV, which is obtained by the polarized reflectance spectrum.

The single crystals of NiPc(SbF6)0.5 and NiPc(AsF6)0.5 were prepared by means of an electrochemical method. The electrical, magnetic, optical, and structural properties of these crystals were examined. These crystals are isostructural to each other, and exhibit a metallic behavior at least above 200 K. The g-values of the ESR signals remarkably depend upon temperature. By the aid of the low temperature experiments of XANES and reflectance spectrum, the temperature dependence is explained by the model based on the interaction between the small amount of local spins on the Ni atoms and the conduction electrons on the ligand chain. In addition, a sample dependence was found on the ESR properties of the crystals of NiPc(AsF6)0.5. This is attributed to the sample dependence of the concentration of the local spins on Ni atoms. From these considerations, we concluded that the ligand part is mainly oxidized in these partially oxidized salts, in other words the conduction electrons are located on the ligand chain....

The title compound was synthesized in a similar manner to a simple access to triple-layered [2.2][2.2]paracyclophane. Its structure was elucidated by X-ray crystallographic analysis. The outer naphthalene rings are bent into a boat form and the inner naphthalene ring is bent into a twist form. These naphthalenes are stacked in layers within van der Waals contact. Therefore, there is a strong transannular π-electronic interaction between them, which brings about characteristic bathochromism, hyperchromism, and broadening in the electronic spectrum. These effects are more prominent than those of the double-layered homologue.

The X-ray photoelectron spectra and the ESR spectra of the (BEDT–TTF)CuCl2 complex were taken. The analysis of the X-ray photoelectron spectra shows that the Cu atoms in (BEDT–TTF)CuCl2 are in a mixed-valence state consisting of mono and bivalent cations and the concentration ratio of Cu(I) and Cu(II) is determined to be 2:1. The ESR signals show the presence of the BEDT–TTF cation radical and Cu(II)Cl2. The temperature dependence of the magnetic susceptibility of these components were obtained from the ESR data.

The crystal structure of a 1:2 complex of bis(methylthio)dithiapyrene and tetrahydrobarreleno–TCNQ contained face-to-face packings of acceptor–donor–acceptor units which are isolated from each other. The IR spectrum, geometry, and absorption spectrum showed the neutral nature of this complex.