Can low-valent germanium chemistry be practiced under ambient conditions? A tale of a water-stable yet reactive germylene monochloride complex

Synthesis and optical properties of antimony(V) complexes of a trianionic N2O2-type tetradentate dipyrrin ligand

LSbCl2, an air- and moisture-stable antimony(V)-dipyrrin complex at room temperature, was obtained by treating an excess amount (20 eq.) of SbCl3 with a trianionic N2O2-type tetradentate dipyrrin ligand (L) under visible-light irradiation and O2 atmosphere. The Cl ligands in LSbCl2 were replaced by OH ligands via hydrolysis, yielding LSb(OH)2. Further, the molecular structures and optical properties of the Sb(V)-dippyrin complexes were investigated. While LSbCl2 was non-fluorescent, LSb(OH)2 exhibited an intense red fluorescence with a photoluminescence quantum yield of 68%.

Easy access to strongly fluorescent higher homologues of BODIPY

We present the easy and high yield synthesis of several group 13 MesDPM compounds (Al-In) with alkyl substituents at the metal atom. All these compounds were fully characterized using techniques including X-ray diffraction analysis and photoluminescence measurements. It shows that for aluminium and gallium pronounced green fluorescence is observed, which is absent for indium. DFT calculations confirm that the first electronic transition corresponds to a ligand-based π-π* transition.

Germylenes Exhibiting Solid-State Emissions that Extend to NIR

Low-valent main group compounds that fluoresce in the solid-state were previously unknown. To address this, we investigated room-temperature photoluminescence from a series of crystals of germylenes 3-8 in this article; they exhibited emissions nearly reaching the NIR. Germylene carboxylates (3-8) were synthesized by reacting dipyrromethene stabilized germylene pyrrolide (2) with carboxylic acids such as acetic acid, trifluoroacetic acid, benzoic acid, p-cyanobenzoic acid, p-nitrobenzoic acid, and acetylsalicylic acid.

Crystalline heaviest pnictogen-dipyrromethenes: isolation, characterization, and reactivity

The heaviest pnictogen-dipyrromethenes DPMPnCl₂ (Pn = Sb, 3; Bi 4), which are direct analogues of boron-dipyrromethene (BODIPY), have been readily prepared and isolated as crystalline solids. Both compounds display green photoluminescence with small full widths at half maximum in toluene. Moreover, the reduction of 3 with sodium metal afforded the cyclic dicoordinate stibinidene 5.

A Prelude to Biogermylene Chemistry*

The biological applications of germylenes remain unrealised owing to their unstable nature. We report the isolation of air-, water-, and culture-medium-stable germylene DPMGeOH (3; DPM=dipyrromethene ligand) and its potential biological application. Compound 3 exhibits antiproliferative effects comparable to that of cisplatin in human cancer cells. The cytotoxicity of compound 3 on normal epithelial cells is minimal and is similar to that of the currently used anticancer drugs. These findings provide a framework for a plethora of biological studies using germylenes and have important implications for low-valent main-group chemistry.

Dipyrrin based metal complexes: reactivity and catalysis

Sometimes named half-porphyrins, bis-pyrrolic dipyrrin ligands endow their metal complexes with unique properties such as the potential to functionalize the heterocyclic backbone or the meso position and the ability to catalyze interesting chemical transformations. Thus, strategies towards the derivatization of or at the meso group and the use of dipyrrin metal complexes for the formation of a broad range of polypyrrolic derivatives such as 2,2'-bis-dipyrrins, nor-/hetero-corroles and porphynoids have been elaborated. Furthermore, the chelating ability of dipyrrins and the possibility of modifying their steric and electronic characteristics by functionalization can be exploited for the development of numerous complexes featuring appealing properties. Hence, C-H activation/amination, polymerization or oxidation reactions can be catalyzed by dipyrrin metal complexes and classical reagents such as Grignard species, Rh-based or Suzuki-Miyaura catalysts have been revisited by incorporation of dipyrrins in the coordination sphere of the metal cations. This contribution aims to review and illustrate all these aspects, highlighting the potential of these complexes for the design and synthesis of valuable organic compounds and metallo-organic architectures.

O,S-Heterocyclic stannylenes: synthesis and reactivity

Commercially available N-oxide (2-mercaptopyridine-N-oxide) is used as a ligand instead of an oxidizing agent to stabilize the compounds of main group elements in low-valent states.