β-Pyrazino-fused tetrarylporphyrins

Abstract

A novel method for the preparation of β-fused porphyrin dyads was developed that exploits a one-pot reaction of 2,3-diaminoporphyrins with diethyl oxalate. This approach provides good yields of the zinc β-fused dyad and the corresponding free-base, opening the way for preparation of several metal derivatives to permit modulation of optoelectronic characteristics for commercial applications.

Control of Conformation and Chirality of Nonplanar π‐Conjugated Diporphyrins Using Substituents and Axial Ligands

“…In con-trast, the twist angles of the porphyrin units in Zn II diporphyrins 1Zn (15.48 and 17.78)a nd 2Zn (9.98 and 9.98)a re significantly lower than those in Ni II diporphyrins 1Ni (56.38 and 56.38)a nd 2Ni (61.38 and 61.38). This result is consistent with the structure of as imilar diporphyrin Zn II complex with phenyls ubstituents reported by Paolesse et al [5] Twom ethanolm olecules in 3Zn coordinate to zinc atoms in an antiparallel fashion in contrast to the cases of 1Zn and 2Zn.S uch ad ifferent conformation among 1Zn, 2Zn,a nd 3Zn indicates that the molecular twisting is mainly induced by meso-aryl groups. [11] The Zn II porphyrin ring in 1Zn and 2Zn adopt domed conformations, whereas the Ni II porphyrin ring 1Ni and 2Ni exhibit ruffled structures with larger twist angles.…”

“…On the other hand, 3Zn adopts C 2h conformation judgingf rom its X-ray diffraction analysis e ). This result is consistent with the structure of as imilar diporphyrin Zn II complex with phenyls ubstituents reported by Paolesse et al [5] Twom ethanolm olecules in 3Zn coordinate to zinc atoms in an antiparallel fashion in contrast to the cases of 1Zn and 2Zn.S uch ad ifferent conformation among 1Zn, 2Zn,a nd 3Zn indicates that the molecular twisting is mainly induced by meso-aryl groups. In addition, the ortho-substituents on the aryl groups are essential to determine whethert he molecule preferentially adopts D 2 or C 2h conformation.…”

“…have elucidated an achiral C 2h conformation for as imilarZ n II pyrazine-fused diporphyrin with meso-phenyl groups. [5] As imilarN i II diporphyrin with meso-phenyl groups was also prepared by Bringmann et al andu sw ithouts tructure elucidation by X-ray analysis. [6] We were then interested in the different D 2 and C 2h conformations of these diporphyrins and decided to investigate the effects of meso-substituents and central metalso nthe conformational preference.…”

“…In contrast, Paolesse et al. have elucidated an achiral C 2 h conformation for a similar Zn II pyrazine‐fused diporphyrin with meso ‐phenyl groups . A similar Ni II diporphyrin with meso ‐phenyl groups was also prepared by Bringmann et al.…”

Oxidative Coupling of an Enaminoporphyrin: C−C, N−N Linkages or Both?

“…[11] The same method was used by Mandoj et al [12] and also appliedt oo ther aromatics. [13] In this study,w e describe the products obtained from the oxidative coupling of an ickel(II) enaminoporphyrin.…”