N. G. Spitsina

Polymer/nanocarbon composite materials for photonics

-phenylene)vinylene](MEH-PPV), and poly(3-hexylthiophene) (P3HT) havebeen obtained [5].To study the microstructure and the surface mor-phology of the CP/NCM films we used a number ofmethods of microscopic studies: transmission electronmicroscopy (TEM) and atomic force microscopy(AFM) [6]. It has been found that the morphology ofthe composite films based on MEH-PPV varies depend-ing on the type of NCM. For example, aza-homo[60]fullerenes form linear structures (tubes with athickness of 100 nm and a length of up to several µm),while C

New molecular metals based on BEDO radical cation salts with the square planar Ni(CN)42− anion

Two new radical cation salts based on bis(ethylenedioxy)tetrathiafulvalene (BEDO) with the square planar Ni(CN)42− anion, (BEDO)4Ni(CN)4·4CH3CN (1) and (BEDO)5Ni(CN)4·3C2H4(OH)2 (2), were synthesized by electrocrystallization. The X-ray structural analysis, electrical transport and magnetotransport properties as well as the calculated Fermi surfaces are presented and discussed. Both salts show metallic properties down to 4.2 K. The nature of the Fermi surface of both salts is discussed and compared with those of other β″ type BEDO salts. On the basis of this comparison it is suggested that salt 2 is a likely candidate to exhibit magnetic breakdown and quantum interference effects in the magnetoresistance. It is shown that salt 1 exhibits unconventional magnetotransport behavior.

Preparation, crystal structure and characterization of C60·2[(Ph3P)AuCl]

Abstract Investigations of crystal structure, infrared spectra and electron spin resonance of the complex of the fullerene C60 with chloro(triphenylophosphine)gold have been performed. It was stated that the C60·2[(Ph3P)AuCl] complex is a molecular crystal in which van der Waals interactions are predominant. The electron spin resonance (ESR) spectrum was discussed and explained. A phase transition at about 195–200 K was suggested.

Synthesis, crystal structure, and spectral studies of the molecular complex of [60]fullerene with chloro(triphenylphosphine)gold(I), C60·2[(Ph3P)AuCl]

The molecular complex C60·2[(Ph3P)AuCl] (1) was synthesized. The crystal and molecular structure of1 was established by X-ray diffraction analysis. At room temperature, the [60]fullerene molecules in complex1 are ordered due to π—π interactions between C60 and the phenyl rings of the chloro(triphenylphosphine)gold(1) molecules. The satellite structure, which accompanies the Cls photoelectron peak of complex1, is indicative of a partial suppression of a channel of losses due to π→π transition in the phenyl ring. The 1R spectral data indicate that either a charge is absent or the charge transfer to the fullerene molecule is negligible.

First radical cаtion salt of bis(ethylenedithio)tetrathiafulvalene with organic anion [С(NCN)2NH2]–: synthesis, structure, and conducting properties

The electrochemical oxidation of bis(ethylenedithio)tetrathiafulvalene (ET) in the presence of simple dicyanamide salts of rare-earth metals with the general formula M[N(CN)2]3 (M = Gd3+, Dy3+, and Ho3+) as electrolytes was studied for the first time. A novel radicalcаtion salt α-ЕТ2[С(NCN)2NH2] with the unexpected (2,1-dicyano)guanidine anion was synthesized. The crystal structure of the salt and its conducting properties were studied. The structure of the salt is layered with alternating conducting radical-cation and insulating anionic layers. The cationic layers of the α-type are formed by two crystallographically independent radical-cations of ET of various charges. The anionic layers are formed of [С(NCN)2NH2]– anions linked by hydrogen contacts into chains. The crystals of ЕТ2[С(NCN)2NH2] demonstrate a semiconducting character of conductivity in a temperature range of 300—100 K.

Synthesis, crystal structure, and conducting properties of a new molecular metal, (BEDO)4Ni(CN)4 · 4CH3CN

A new radical cation salt based on bis(ethylenedioxy)tetrathiafulvalene (BEDO) with the planesquare anion Ni(CN)42− is synthesized. The molecular and crystal structures of the radical cation salt are determined, and the conducting properties are investigated. In the structure, the BEDO radical cations have a β″-type packing. It is shown that the temperature dependence of the conductivity of (BEDO)4Ni(CN)4 · 4CH3CN crystals exhibits metallic behavior.

A new molecular C60 complex with bis(methylenedithio)tetrathiafulvalene (BMDT-TTF): Synthesis, crystal structure, and properties

A new molecular C60 complex of the composition (BMDT-TTF) · C60 · 2CS2 (I) with the bis(methylenedithio)tetrathiafulvalene (BMDT-TTF) organic donor is synthesized. The molecular and crystal structures of this complex are determined by x-ray diffraction. The (BMDT-TTF) · C60 · 2CS2 (I) compound crystallizes in a monoclinic crystal system. The main crystal data are as follows: a=13.550(5) Å, b=9.964(7) Å, c=17.125(8) Å, β=99.52(4)°, V=2280(2) Å3, M=1229.45, and space group P21/m. Crystals of I have a layered structure: layers consisting of C60 molecules alternate with layers composed of BMDT-TTF and CS2 molecules. It is found that, in complex I, the donor and C60 molecules are linked through the shortest contacts, which leads to a change in the molecular geometry of BMDT-TTF. The donor molecules in a crystal layer are characterized by the shortest S...S contacts. The IR data indicate the electroneutrality of the fullerene molecule. The electrical conductivity of (BMDT-TTF) · C60 · 2CS2 single crystals is measured using the four-point probe method at room temperature: σRT=2×10−5 Ω−1 cm−1.

Molecular complex of C60 fullerene with an organic π-donor, bis(methylenedithiotetrathiafulvalene): synthesis, crystal structures, and properties

A new molecular complex based on [60]fullerene, namely, (BMDT-TTF)·C60·2CS2 (1) (where BMDT-TTF is bis(methylenedithiotetrathiafulvalene)) was synthesized. The molecular and crystal structures of 1 were established by X-ray diffraction analysis. Complex 1 has a layered structure, layers of C60 molecules alternating with those formed by BMDT-TTF molecules and CS2 molecules located between them. In complex 1, there are short contacts between C60 and the donor molecules, which results in a changed BMDT-TTF geometry. The donor molecules in 1 form in addition short S...S contacts. The data of IR spectroscopy indicate that the charge transfer to the fullerene molecule is insignificant if at all present. The conductivity of a single crystal of 1 measured at ∼20 °C using a four-contact method is 2·10–5 (Ω cm)–1.

Molecular Complex of [60]Fullerene with 2-(4-thione-l,3-dithiolan-5-yliden)-4,5-dimethyl-1,3-diselenol [C60·2(DTDS)]: Synthesis, Crystal Structure and Properties

Abstract New molecular complexes of [60]fullerene with 2-(4-thione-l,3-dithiolan-5-yliden)-4,5-dimethyl-l,3-diselenol [C60·2(DTDS)] have been synthesized, crystal structure, IR spectral and electrochemical properties have been studied. Partial charge transfer has been found. An unusual shortening of the endocyclic S-C(sp2) bond in the DTDS molecule has been found to be stipulated by conformational vibrations of the >CH2 group. A comparative analysis of the X-ray data for the [C60·2(DTDS)] crystals and the quantum chemical calculations (SCF MO, 6-31G* basis) for the DTDS molecules and its radical ions showed charge transfer not to be the cause for the shortening of the exocyclic C=S bonds.

Synthesis and crystal structure of the molecular complex of fullerence C60 with 2-(4-thiono-1,3-dithiolan-5-ylidene)-4,5-dimethyl-1,3-diselenol (C60·2DTDS)

A new molecular complex of fullerene C60 with 2-(4-thiono-1,3-dithiolan-5-ylidene)-4,5-dimethyl-1,3-diselenol (C60·2DTDS) was synthesized for the first time. The crystal and molecular structures of C60·2DTDS were established by X-ray diffraction analysis. The crystal structure of C60·2DTDS is layered: the layers of fullerene C60 molecules alternate with those of DTDS molecules. The molecules of C60 and DTDS are associated by shortened C...Se, C...S, and C...C contacts forming a three-dimensional network of secondary interactions in the crystal. The C60·2DTDS crystals have a specific feature: the absence of shortened C...C contacts between the nearest C60 molecules despite the short distances between their centers, 9.948(2) and 10.054(2) Å. The electrochemical properties of DTDS were studied by cyclic voltammetry in CH2Cl2/0.05M Bu4NPF6 at room temperature. DTDS undergoes reversible one-electron reduction to a radical anion [Eo=−1.81 V (Fc0/+)] and reversible one-electron oxidation to a radical cation [Eo=+0.37 V (Fc0/+)]. The degree of charge transfer in C60·2DTDS, ΔN=0.18, calculated from the electrochemical parameters of DTDS and C60 indicates that this compound is a molecular complex with a partial charge transfer.