Combination of illumination and high resolution NMR spectroscopy: Key features and practical aspects, photochemical applications, and new concepts.

In the last decade, photochemical and photocatalytic applications have developed into one of the dominant research fields in chemistry. However, mechanistic investigations to sustain this enormous progress are still relatively sparse and in high demand by the photochemistry community. UV/Vis spectroscopy and EPR spectroscopy have been the main spectroscopic tools to study the mechanisms of photoreactions due to their higher time resolution and sensitivity.

Photoinitiated carbonyl-metathesis: deoxygenative reductive olefination of aromatic aldehydes photoredox catalysis.

Carbonyl-carbonyl olefination, known as McMurry reaction, represents a powerful strategy for the construction of olefins. However, catalytic variants that directly couple two carbonyl groups in a single reaction are less explored. Here, we report a photoredox-catalysis that uses Bpin as terminal reductant and oxygen trap allowing for deoxygenative olefination of aromatic aldehydes under mild conditions.

Elusive Zintl Ions [μ-HSi ] and [Si ] in Liquid Ammonia: Protonation States, Sites, and Bonding Situation Evaluated by NMR and Theory.

The existence of [μ-HSi ] in liquid ammonia solutions is confirmed by H and Si NMR experiments. Both NMR and quantum chemical calculations reveal that the H atom bridges two Si atoms of the [Si ] cluster, contrary to the expectation that it is located at one vertex Si of the tetrahedron. The calculations also indicate that in the formation of [μ-HSi ] , protonation is driven by a high charge density and an increase of electron delocalization compared to [Si ] .