Conformational Changes and Redox Properties of Bimetallic Single Helicates of Hexapyrrole-α,ω-dicarbaldehydes.

The hexapyrrole-α,ω-dicarbaldehydes 1 a and 1 b were metallated with Cu , Ni , and Pd to give bimetallic complexes where a pair of 3 N+O four-coordinate metal planes are helically distorted and the central 2,2'-bipyrrole subunit adopts a cis or trans conformation. X-ray crystallographic analysis of the bisCu complex revealed a closed form with a cis-2,2'-bipyrrole subunit and an open form with a trans-2,2'-bipyrrole subunit. The bisPd complexes took a closed form both in the solid state and in solution.

2,2'-Bipyrrole-Based Porphyrinoids.

A large number of porphyrinoids containing 2,2'-bipyrrole subunits have appeared since they were originally found as a component of sapphyrin and corrole, and it was found that the bipyrrole subunit endowed macrocycles with specific geometric features and electronic properties. Synthetic methods for bipyrrole-containing precursors for porphyrinoid are summarized in this review; these include coupling reactions of pyrrole rings, pyrrole ring-forming reactions leading directly to bipyrrole units, and synthetic reactions for oligopyrrolic compounds. Some hybrid oligopyrroles having nonpyrrole (hetero)aromatic ring(s) are also included.

Solvent-dependent dual-mode photochromism between T- and P-types in a dipyrrinone derivative.

A newly synthesized dipyrrinone derivative bearing an ethoxycarbonyl group at the pyrrolic-α position exhibited solvent-dependent dual-mode photochromism between T- and P-types. While this molecule underwent thermally reversible (T-type) photoresponsive reaction in chloroform, it became a thermally irreversible (P-type) system in methanol.

The synthesis and dynamic structures of multinuclear complexes of large porphyrinoids expanded by phenylene and thienylene spacers.

1,3-Bis(2-pyrryl)benzene was used to prepare dibenziamethyrin, in which two pyrrole units of [24]amethyrin(1.0.0.

Synthesis and antiaromatic properties of highly planar dithiaamethyrin.

2,5-Bis(4-propyl-2-pyrrolyl)thiophene was reacted with aryl aldehydes to afford large porphyrinoids; [24]dithiaamethyrin(1.0.0.

One-handed single helicates of dinickel(II) benzenehexapyrrole-α,ω-diimine with an amine chiral source.

Benzenehexapyrrole-α,ω-dialdehyde, composed of a pair of formyltripyrrole units with a 1,3-phenylene linker, was metallated to give dinuclear single-stranded helicates. X-ray studies of the bis-nickel(II) complex showed a helical C2 form with a pair of helical-metal coordination planes of a 3N+O donor set. The terminal aldehyde was readily converted into the imine by optically active amines, whereby helix-sense bias was induced.

Bis-naphthobipyrrolylmethene derived BODIPY complex: an intense near-infrared fluorescent dye.

Synthesis of a novel π-extended BODIPY derived from naphthobipyrrole is presented. This dye molecule displays very intense near-infrared (NIR) absorption (ε > 400,000 M(-1) cm(-1)) and emission bands (>700 nm), accompanied by high quantum yield (φf = 0.65) owing to its extended π-conjugation along with imposed structural rigidification.

Highly reactive meso-like positions of dipyrihexaphyrin.

The meso-like position of a pyridine-containing porphyrin analogue structurally related to amethyrin was found to be highly reactive to undergo addition of alcohols, amines and hydrogen cyanide at room temperature under neutral conditions.

Synthesis and dynamic structure of multinuclear Rh complexes of porphyrinoids.

Large porphyrinoids with three Rh(CO)2 groups at their dipyrrin units shows two-step metal transposition through the macrocycle in solution and the equilibrium between the C3v-isomer and the Cs-isomer depends on the solvent polarity.

Synthesis of bis(azafulvene)s by dehydration of hydroxymethylpyrrole derivatives.

Bis(azafulvene) was isolated in 55% yield by the reaction of 4 equivalents of phenyllithium with 5,5'-diformyl-3,3',4,4'-tetraethyl-2,2'-bipyrrole followed by quenching with acetic anhydride. Unstable bis(azafulvene)s were obtained in much higher yields by dehydrating 5,5'-bis(hydroxymethyl) derivatives of 2,2'-bipyrrole and gem-dimethyl-2,2'-dipyrrylmethane with (Boc)2O-DMAP at room temperature. X-Ray crystallography of two bis(azafulvene)s is reported.