A Knowledge-Based Molecular Single-Source Precursor Approach to Nickel Chalcogenide Precatalysts for Electrocatalytic Water, Alcohol, and Aldehyde Oxidations.

The development and comprehensive understanding of nickel chalcogenides are critical since they constitute a class of efficient electro(pre)catalysts for the oxygen evolution reaction (OER) and value-added organic oxidations. This study introduces a knowledge-based facile approach to analogous NiE (E = S, Se, Te) phases, originating from molecular β-diketiminato [NiE] complexes and their application for OER and organic oxidations. The recorded activity trends for both target reactions follow the order NiSe > NiS > NiTe.

Disilicon-Mediated Carbon Monoxide Activation: From a 1,2,3-Trisila- to 1,3-Disilacyclopentadienes with Hypercoordinate λSi-λC Double Bonds.

The facile reaction of the SiPh-bridged bis-silylene (LSi:)SiPh (L=PhC(NBu)) with diphenylacetylene affords the unprecedented 1,2,3-trisilacyclopentadiene (LSi)(PhC)SiPh 1 with a hypercoordinate λSi-λSi double bond. Compound 1 is very oxophilic and consumes three molar equivalents of inert NO to form the bicyclic oxygenation product 2 through O-atom insertion in the Si=Si and Si-Si bonds. Strikingly, 1 can completely split the C≡O bonds of carbon monoxide under ambient conditions (1 atm, room temperature), yielding the 1,3-disilacyclopentadiene 3, representing the first hypercoordinate example of a cyclosilene with a λSi-λC double bond.

Bis-Silylene-Supported Aluminium Atoms with Aluminylene and Alane Character.

The suitability of electron-rich bis-silylenes, specifically the neutral chelating [Si(Xant)Si] ligand (Si=PhC(NBu)Si, Xant=9,9-dimethylxanthene) and the anionic [Si(N)Si)] pincer ligand (N=2,7,9,9-tetramethylacridane), has been successfully probed to stabilize monovalent bis-silylene-supported aluminium complexes (aluminylenes). At first, the unprecedented aluminium(III) iodide precursors [Si(Xant)Si]AlI I 1 and [Si(N)Si)]AlI 2 were synthesized using AlI and [Si(Xant)Si] or [Si(N)Si)]Li(OEt)], respectively, and structurally characterized. While reduction of 1 with KC led merely to unidentified products, the dehalogenation of 2 afforded the dimer of the desired {[Si(N)Si)]Al:} aluminylene with a four-membered Si Al ring.

Silylene-Stabilized Neutral Dibora-Aromatics with a B═B Bond.

The unprecedented silylene-supported dibenzodiboraoxepin and 9,10-diboraphenanthrene complexes and were synthesized. The (NHSi)B(xanthene) [NHSi = PhC(NtBu)(MeN)Si:] results from debromination of the bis(NHSi)-stabilized bis(dibromoboryl)xanthene with potassium graphite (KC); is capable of activating white phosphorus and ammonia to form the BP cage compound and HN-B-B-H diborane species , respectively. The thermal rearrangement of affords the 9,10-dihydro-9,10-diboraphenanthrene through a bis(NHSi)-assisted intramolecular reductive C-O-C deoxygenation process.

Stabilizing Monoatomic Two-Coordinate Bismuth(I) and Bismuth(II) Using a Redox Noninnocent Bis(germylene) Ligand.

The formation of isolable monatomic Bi complexes and Bi radical species is challenging due to the pronounced reducing nature of metallic bismuth. Here, we report a convenient strategy to tame Bi and Bi atoms by taking advantage of the redox noninnocent character of a new chelating bis(germylene) ligand. The remarkably stable novel Bi cation complex , supported by the new bis(iminophosphonamido-germylene)xanthene ligand [(P)Ge(Xant)Ge(P)] , [(P)Ge(Xant)Ge(P) = PhP(NBu)Ge(Xant)Ge(NBu)PPh, Xant = 9,9-dimethyl-xanthene-4,5-diyl], was synthesized by a two-electron reduction of the cationic BiI precursor complex with cobaltocene (CpCo) in a molar ratio of 1:2.