Hiroki Akutsu

Metallic molecular crystals containing chiral or racemic guest molecules

Metallic charge-transfer salts of BEDT-TTF containing both racemic (R/S)- and chiral (S)-sec-phenethyl alcohol as guest molecules have been crystallised and their structures and physical properties are compared.

Chiral conducting salts of BEDT-TTF containing a single enantiomer of tris(oxalato)chromate(III) crystallised from a chiral solvent

Two polymorphs of a chiral conductor formulated (BEDT-TTF)3NaCr(C2O4)3·CH3NO2 have been crystallised from a solution containing the racemic anion tris(oxalato)chromate(III). In the presence of (R)-(−)-carvone the electrocrystallisation of Na3Cr(C2O4)3 with BEDT-TTF and nitromethane yields two products: hexagons crystallising in the space group P212121 (I) and needles in the space group P21 (II). Single crystal electrical transport measurements show semiconducting behavior for both salts.

Preparation and Properties of Organic Radical Compounds with Mesogenic Cores

Several organic spin systems based on 4-(N-alkyl)amino-TEMPO (TEMPO = 2,2,6,6-tetramethylpiperidinyl-1-oxy) radicals were prepared in which cholesterol or biphenyl mesogenic cores with long alkyl or alkoxy substituents were incorporated in order to investigate the possible occurrence of liquid crystalline properties. Of these radicals a lamellar structure was found in a biphenyl derivative with the 4-(N-methyl)amino-TEMPO-substituent 13; this compound showed mesogenic properties. The local antiferromagnetic spin interactions based on a singlet-triplet model observed during the heating process in the radical were found to turn to a Curie−Weiss behavior after the thermal transition during the cooling process. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

Preparation and characterization of novel organic radical anions for organic conductors : TEMPO-NHSO3- and TEMPO-OSO3-

The preparation and characterization of new organic radical anions TEMPO-NHSO 3 . (tsfa) and TEMPO-OSO 3 - (tosu), which consist of the organic stable radical (TEMPO) and the anionic functional group (-NHSO 3 - or -OSO 3 - ), has been investigated. The molecular and crystal structures of bis(triphenylphosphoranylidene)ammonium.tsfa determined by X-ray analysis indicate that tsfa exists as a monovalent anion. Black powders of the TTF.tsfa and TTF.tosu salts were obtained, in each of which the donor to anion ratio is found to be 1 : 1 by elemental analysis. TTF.tsfa shows a weak antiferromagnetic interaction with C = 0.360 emu K mol -1 and θ = -0.52 K.

A molecular charge transfer salt of BEDT-TTF containing a single enantiomer of tris(oxalato)chromate(III) crystallised from a chiral solvent

The first chiral BEDT-TTF-tris(oxalato)metallate(III) salt has been crystallised from a solution containing the racemic anion in the chiral solvent (R)-(−)-carvone.

The first examples of discotic radicals: columnar mesomorphism in spin-carrying triphenylenes

The synthesis, columnar behaviour and magnetic properties of the first examples of radical discotics are reported. These organic molecular systems with spin sources have been accomplished by covalently linking triphenylene with molecular radicals. The columnar mesomorphism of these new radicals has been established unambiguously using several complementary techniques. Magnetic susceptibility measurements in the fluid columnar, frozen columnar and solid states reveal the antiferromagnetic intermolecular interactions of Curie–Weiss behaviour.

A series of two oxidation reactions of ortho-alkenylbenzamide with hypervalent iodine(III): a concise entry into (3R,4R)-4-hydroxymellein and (3R,4R)-4-hydroxy-6-methoxymellein.

A sequence of oxidation reactions of alkenamides with hypervalent iodine is described. Oxidation of ortho-alkenylbenzamide substrates selectively gave isochroman-1-imine products. The products underwent further oxidation in the presence of a Pd salt catalyst leading to regioselective C-H acetoxylation at the 8-position. A series of oxidations was applied to the crucial steps of asymmetric synthesis of 4-hydroxymellein derivatives.

Metal–Insulator, SDW, and Glass Transitions in the Organic Conductors, (DMET) 2BF 4 and (DMET) 2ClO 4, Studied by ac Calorimetry [rf:1]

Temperature dependence of the heat capacities of two organic conductors, (DMET) 2 BF 4 and (DMET) 2 ClO 4 , was measured by chopped-light ac calorimetry between 10 and 300 K. A “Mott-like” nature o...

A new organic superconductor, β-(BDA-TTP)2GaCl4[BDA-TTP = 2,5-(1,3-dithian-2-ylidene)-1,3,4,6-tetrathiapentalene]

The preparation, crystal structure and physical properties of beta-(BDA-TTP)2GaCl4 has been investigated; the salt exhibits superconductivity at 3.1 K (onset) under a hydrostatic pressure of 7.6 kbar.

Chirality in charge-transfer salts of BEDT-TTF of tris(oxalato)chromate(III)

Crystallisation from chiral electrolyte (R)-(−)-carvone has produced three new chiral semiconducting salts of BEDT-TTF from racemic anion tris(oxalato)chromate(III).