The archetype ionic transition‐metal complexes (iTMCs) [Ir(ppy)2(bpy)][PF6] and [Ir(ppy)2(phen)][PF6], where Hppy = 2‐phenylpyridine, bpy = 2,2′‐bipyridine, and phen = 1,10‐phenanthroline, are used as the primary active components in light‐emitting electrochemical cells (LECs). Solution and solid‐state photophysical properties are reported for both complexes and are interpreted with the help of density functional theory calculations. LEC devices based on these archetype complexes exhibit long turn‐on times (70 and 160 h, respectively) and low external quantum efficiencies (∼2%) when the complex is used as a pure film. The long turn‐on times are attributed to the low mobility of the counterions. The performance of the devices dramatically improves when small amounts of ionic liquids (ILs) are added to the Ir‐iTMC: the turn‐on time improves drastically (from hours to minutes) and the device current and power efficiency increase by almost one order of magnitude. However, the improvement of the turn‐on time is unfortunately accompanied by a decrease in the stability of the device from 700 h to a few hours. After a careful study of the Ir‐iTMC:IL molar ratios, an optimum between turn‐on time and stability is found at a ratio of 4:1. The performance of the optimized devices using these rather simple complexes is among the best reported to date. This holds great promise for devices that use specially‐designed iTMCs and demonstrates the prospect for LECs as low‐cost light sources.

Dye-sensitized solar cells with carboxylate-derivatized {Cu(I)L(2)} complexes are surprisingly efficient and offer a long-term alternative approach to ruthenium-functionalized systems.

Light‐emitting electrochemical cells with lifetimes surpassing 3000 hours at an average luminance of 200 cd m−2 are obtained with an ionic iridium(III) complex conveniently designed to form a supramolecularly caged structure.

Members of the diazeniumdiolate class of natural compounds show potential for drug development because of their antifungal, antibacterial, antiviral, and antitumor activities. Yet, their biosynthesis has remained elusive to date. Here, we identify a gene cluster directing the biosynthesis of the diazeniumdiolate compound fragin in Burkholderia cenocepacia H111. We provide evidence that fragin is a metallophore and that metal chelation is the molecular basis of its antifungal activity. A subset of the fragin biosynthetic genes is involved in the synthesis of a previously undescribed cell-to-cell signal molecule, valdiazen. RNA-Seq analyses reveal that valdiazen controls fragin biosynthesis and affects the expression of more than 100 genes. Homologs of the valdiazen biosynthesis genes are found in various bacteria, suggesting that valdiazen-like compounds may constitute a new class of signal molecules. We use structural information, in silico prediction of enzymatic functions and biochemical data to propose a biosynthesis route for fragin and valdiazen.

Light-emitting electrochemical cells (LECs) containing [Cu(POP)(N^N)][PF6] (POP = bis(2-diphenylphosphinophenyl)ether, N^N = 6-methyl- or 6,6'-dimethyl-2,2'-bipyridine) exhibit luminance and efficiency surpassing previous copper(I)-containing LECs.