Pyrroles fused with aromatic rings (isoindole derivatives) have been readily prepared by the reaction of aromatic nitro compounds with ethyl isocyanoacetate in the presence of DBU. The ease of this reaction depends on the aromaticity of the starting nitro aromatics. Polycyclic aromatic nitro compounds such as 1-nitroacenaphthylene or 9-nitrophenanthrene are more reactive than simple nitro aromatics such as nitrobenzene or nitronaphthalenes and give the corresponding pyrroles in good yields. Pyrroles prepared by this method have been converted into porphyrins fused with various aromatic rings by the reduction with LiAlH, followed by treatment with an acid catalyst and oxidation with chloranil or oxygen. Tetra-lY2-naphthoporphyrin has been prepared by the reaction of 2-nitro-3,4dihydronaphthalene or 1-nitronaphthalene with ethyl isocyanoacetate followed by reduction, tetramerization and oxidation. Thus, highly conjugated porphyrins are readily prepared starting from aromatic nitro compounds, and their electronic and optical properties can be controlled by choice of the starting aromatic nitro compound.

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A mixture of 2,2,6,6-tetramethyl-1-piperidinyloxyl (TEMPO) radical and 2,2,6,6-tetramethyl-1-piperidine (TEMP) was included into organic 1-D nanochannels of tris(o-phenylenedioxy)cyclotriphosphazene (TPP) crystal. Dilution of the paramagnetic TEMPO radical was achieved with excess TEMP, thereby isolating a TEMPO molecule in the nanochannel. For inclusion compounds of TPP with TEMPO and TEMP (TEMPO/all guest compounds = 0.017, and 0.15), temperature-dependent electron spin resonance (ESR) spectra were observed to investigate their molecular dynamics and orientation. In the temperature range from 112 K to room temperature, the spectra depended remarkably on the temperature. Temperature dependence was well interpreted by uniaxial rotation, suggesting that TEMPO molecules undergo uniaxial rotation about a channel axis with a molecular orientation in which the N-O bond in the nitroxide group is perpendicular to the channel axis. The activation energy of uniaxial rotation was evaluated as 4.5 +/- 0.3 kJ mol(-1).

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We recently developed ionic liquids containing cationic sandwich complexes. However, salts of the sandwich complexes often exhibit ionic plastic phases with high melting points. To explore the boundaries between ionic liquids and plastic crystals of sandwich salts, we investigated, in detail, the phase behavior of ruthenium complexes [Ru(CH)(CHR)][X] ([C0][X]: R = H, [C1][X]: R = Me, [C2][X]: R = Et, [C4][X]: R = Bu). Among salts containing the anions PF, FSA, and B(CN), [C0][X] and [C1][X] are solids that exhibit plastic phases at or above room temperature, whereas [C2][X] and [C4][X] are mostly ionic liquids. Salts containing the C(CN) anion exhibited lower melting points than the other salts. X-ray crystallography reveals that the cations and anions in most of these salts are arranged alternately in the solid state. However, in the case of [C0][C(CN)], the cations and anions are stacked independently, thereby providing weaker cation-anion interactions that account for the relatively low melting point of this salt.