On the structure of the alkanol propentdyopent adducts

Abstract

A new high-yielding preparation of alkanol propentdyopents is discovered and used to confirm the structure for this system as the valley adduct [e.g. structure (I)].

Redox‐Switchable Cyan Fluorescence of a BODIPY Analog Inspired by Propentdyopent Pigments

“…The tetraethyl propentdyopent ligand was prepared as described previously and isolated as a methanolic adduct . The formation of a yellow/green fluorescent product was observed upon mixing Hpdp · MeOH with BF 3 · OEt 2 in toluene under reflux conditions for 15 minutes (Scheme ).…”

“…The tetraethyl propentdyopent ligand was prepared as described previously and isolated as a methanolic adduct. [22] The formation of a yellow/green fluorescent product was observed upon mixing Hpdp·MeOH with BF 3 ·OEt 2 in toluene under reflux conditions for 15 minutes (Scheme 2). Notably, longer reaction times led to lower yields and/or decomposition of the product, whereas reflux at lower temperatures (for instance in tetrahydrofuran, with or without a base) did not afford the desired complex.…”

“…[18][19][20] We have shown that tetraethyl propentdyopent Hpdp coordinates divalent transition metals and that the resulting homoleptic pseudo-tetrahedral complexes [M(pdp) 2 , Scheme 1] host stable ligand-based radicals upon one-electron reduction. [21] Although convenient syntheses of dipyrrindione ligands were first reported in the 1980s, [22][23][24] their boron coordination has not been investigated to the best of our knowledge. Herein, we sought to combine the ability of the dipyrrindione moiety to act as a redox-active ligand with the emission properties of BODIPY analogs to afford a novel redox-switchable fluorophore.…”

Propentdyopent: the scaffold of a heme metabolite as an electron reservoir in transition metal complexes

“…An all-ethyl analog of the naturally occurring propentdyopents (which typically feature methyl, vinyl or propionate substituents) was prepared from the photo-oxygenation of tetraethyldipyrrinone (aka tetraethylpyrromethenone) and isolated as the methanol adduct HpdpÁMeOH as previously reported. 6,16,17 Propentdyopent complexes were prepared in good yields by briefly refluxing (10-30 min) methanolic solutions of HpdpÁMeOH in the presence of chloride or acetate salts of Co(II), Ni(II), Cu(II), and Zn(II) (see ESI † for experimental details). The progress of metal coordination was monitored by UV-visible absorption spectroscopy owing to the p-p* transitions in the visible region that are characteristic of dipyrrin complexes (Fig.…”

“…4 Subsequent studies over a period of five decades established the molecular structure of the propentdyopent family as well as the formation of colorless adducts in the presence of nucleophilic solvents such as water and methanol (Chart 1). 5,6 Propentdyopent pigments are structurally related to the bidentate ligands of the large family of dipyrrins, 7 which form dipyrrinato metal complexes employed widely in multiple applications including fluorescent labels for bioimaging (i.e., BODIPY dyes), 8 coordination polymers, [9][10][11] and catalysts. 12 In spite of this similarity with a versatile family of ligands, the coordination chemistry of propentdyopents remains rather unexplored.…”