Hideyuki Tukada

Control of electronic structure of a six-coordinate iron(III) porphyrin radical by means of axial ligands

Addition of tert-butylisocyanide (tBuNC) to a CD2Cl2 solution of the bis(perchlorato)(meso-tetramesitylporphyrinato) iron(III) cation radical leads to the formation of the corresponding bis(adduct), [Fe(TMP)(tBuNC)2]2+, whose electronic structure is in sharp contrast to that of the corresponding imidazole(HIm) complex, [Fe(TMP)(HIm)2]2+; the former adopts the S = 0 while the latter exhibits the S = 1 electronic ground state.

(3-Nitrenophenyl)methylene: a ground state quintet molecule having both carbenic and nitrenic atoms

(3-Nitrenophenyl)methylene (1), a non-Kekule molecule with quintet ground state, has been generated photochemically from (3-azidophenyl)diazomethane in organic matrix at cryogenic temperatures.

Structures and short contacts of F⋯O(nitro) and H⋯O(nitro) in 2,2-di(4-nitrophenyl)hexafluoropropane and 2,2-di(4-nitrophenyl)propane

Abstract 2,2-Di(4-nitrophenyl)hexafluoropropane ( 1 ) and 2,2-di(4-nitrophenyl)propane ( 2 ) were synthesized and their crystal structures were determined. The crystals of both diarylpropanes have helical conformations with unsymmetrical ring-twist angles, φ A =46.7, φ B =33.5° for 1 , and φ A =64.9, φ B =31.8°, for 2 . In contrast, density functional theory calculations indicate symmetrical, helical C 2 states for both 1 ( φ A = φ AB =43.1°) and 2 ( φ A = φ B =51.5°). Intermolecular π–π-stacks along the a -axis of the crystals are composed of a pair of nitrophenyl rings oriented in opposite directions. Short contacts of O(nitro)⋯F and O(nitro)⋯H(Me) within the sum of van der Waals radii were also found in 1 and 2 , respectively.

New Classes of Organic High-Spin Molecules Generated with Electron-Doping

Abstract Two types of novel organic high-spin molecules are generated with electron doping; (1) 3-nitrenobenzyl, (2) l,3-di(l-naphthyl)benzene dianion diradical.

3-Ylomethylphenylnitrate a novel quartet species having doubly heterogeneous radical sites (N and C atom; S= 1 and 1/2 center) in a π-conjugated molecule

The ground-state quartet species, 3-ylomethylphenylnitrene 1, is photochemically generated from two precursors, 2 and 3, and is characterized using ESR spectroscopy in the temperature range 8–80 k in a 2-methyltetrahydrofuran (MTHF) matrix.

Diradical diions of m-bis(naphthyl) and (anthyryl) phenylenes as new high-spin molecules

Ferromagnetic spin alignment is observed in double one-electron-oxidized or -reduced conjugated molecules, m-bis(9-anthryl) phenylene dication diradical 12˙+ and m-bis(1-naphthyl) phenylene dianion diradical 22˙–, based on EPR experiments at cryogenic temperature.

(9,10-Dihydro-9,10-o-benzeno-2,6-anthrylene)di(phenylmethylene): a ground state quintet molecule

The title molecule, which has two diphenylmethylene moieties in a rigid triptycene skeleton, is photochemically generated from the corresponding diazo compound at cryogenic temperature in an ESR cavity, and the ESR spectra is identified with a quintet ground state, with ZFS parameters, |D|/hc= 0.0665 and |E|/hc= 0.0043 cm–1, respectively.

Synthesis of tetrathiafulvalene (TTF) derivatives bearing long alkyl chains

The preparation of tetrahiadfulvalene derivatives [(3), (7a), and (7b)] substituted with hydrophobic alkyl chains is described.

Studies on Aculeines: Synthetic Strategy to the Fully Protected Protoaculeine B, the N-Terminal Amino Acid of Aculeine B

A synthetic strategy for accessing protoaculeine B (1), the N-terminal amino acid of the highly modified peptide toxin aculeine, was developed via the synthesis of the fully protected natural homologue of 1 with a 12-mer poly(propanediamine). The synthesis of mono(propanediamine) analog 2, as well as core amino acid 3, was demonstrated by this strategy. New amino acid 3 induced convulsions in mice; however, compound 2 showed no such activity.

Investigation of New Cooling Paints Based on Copolymers of N-Isopropylacrylamide with Butyl Acrylate and N,N-Dimethylacrylamide

New cooling paints were developed by exploiting the vaporization heat of water. These systems were prepared using various ratios of three copolymer components N-isopropylacrylamide (NIPAAm), butyl acrylate (BA), and N,N-dimethylacrylamide (DMAAm). The homopolymer of NIPAAm dissolves in water below about 32°C (hydrophi lic) and becomes insoluble above this temperature (hydrophobic). On the basis of the hydrophobic/hydrophilic switch of NIPAAm polymers, cooling paints consisting of copolymers of NIPAAm with coating materials were investigated. Copolymers of NIPAAm with BA (NIPAAm-co-BA) showed cooling effects; however, the hydrophobic/hydrophilic switch temperature decreased with the BA ratio. Copolymerization of NIPAAm-co-BA and DMAAm allowed us to adjust the switch temperature to about 30°C. In