Tripyrrin-armed isosmaragdyrins: synthesis, heterodinuclear coordination, and protonation-triggered helical inversion

Abstract

A tripyrrin-armed isosmaragdyrin containing a β,β-linked bipyrrole moiety has been synthesized from a linear octapyrrole, and the succeeding metallation afforded an enantiomer pair of mononuclear NiII- and heterodinuclear NiII/CuII-complexes that exhibit P- and M-helices.

A Chiral Metal-Organic 1D-Coordination Polymer Upon Complexation of Phenylene-Bridged Bipyrrole and Palladium (II) Ion

“…We have previously synthesized N-hexyl BPI and found in the crystal structure that two pyrrole components adopt a twisted geometry with an anti-folded confirmation through the phenylene spacer (Ie et al, 2015). The dihedral angle of pyrrole and phenylene components is 33.3 • on average, owing to the steric repulsions between the ethyl group attached to the pyrrole-β and phenylene ring (Li et al, 2020). This observed twisted structure allows our FIGURE 2 | 1 H NMR spectra (400 MHz, CDCl 3 ) of (A) BPI-1 and (B) a product formed upon mixing BPI-1 and Pd(OAc) 2 at 1:1 ratio.…”

Synthesis, structure, and properties of palladium(ii) complex of α-formyl pyrrolyl dipyrromethene

“…However, the coordination chemistry of linear tripyrroles and longer oligopyrroles is still in the early stages and the full potential of the higher analogues of linear pyrrole-based ligands has not been well studied. 10,13 Recently, tripyrrins as well as tetrapyrrins have been exploited as ligands for metal coordination chemistry ( 3 & 4 ) as these oligopyrrole ligands have the ability to coordinate transition metals in multiple oxidation states. 13,14 For example, Tomat and co-workers 15 have used the tripyrrin-1,14-dione ligand to prepare stable Pd( ii ) complexes in which Pd( ii ) was coordinated to three pyrrole nitrogens and the fourth position was occupied by H 2 O.…”

“…10,13 Recently, tripyrrins as well as tetrapyrrins have been exploited as ligands for metal coordination chemistry ( 3 & 4 ) as these oligopyrrole ligands have the ability to coordinate transition metals in multiple oxidation states. 13,14 For example, Tomat and co-workers 15 have used the tripyrrin-1,14-dione ligand to prepare stable Pd( ii ) complexes in which Pd( ii ) was coordinated to three pyrrole nitrogens and the fourth position was occupied by H 2 O. However, the tripyrrins and tetrapyrrins have a tendency to degrade in the presence of acids, bases and oxygen which limits their metal coordination chemistry.…”

“…13 b ,16 Thus, fewer examples of the metal coordination complexes of tripyrrins and higher analogues have been reported in the literature. 13–16…”

Chain Length Modulated Dimerization and Cyclization of Terminal Thienyl-Blocked Oligopyrranes

“…However, syntheses of long-chain oligopyrrins are rather challenging . In this respect, we have successfully synthesized an octapyrrin through oxidative dimerization of the corresponding bilane with one of the terminal positions blocked by an electron-deficient pentafluorobenzoyl unit, and the resulting octapyrrin could be further oxidized to afford an oligopyrrin-appended pentaphyrin analogue, P-OMe (Figure b) …”