The selective electrocatalytic conversion of CO2 into multicarbon products, such as ethanol, is a major technological challenge. Currently, this reactivity is limited by the sluggish formation of C-C bonds inherent to many single-site catalysts. Here, we report a new tandem electrocatalyst based on earth-abundant elements, which facilitates the selective CO2-to-ethanol conversion. The composite catalyst consists of neighboring cobalt and copper atoms anchored to electrically conductive nitrogen-doped carbon. At low overpotentials (E = -0.8 V vs reversible hydrogen electrode), the system shows high selectivity for ethanol production (faradaic efficiencies >70%), while retaining its reactivity and stability for 18 h. A CO spillover mechanism is proposed as the basis for the observed selectivity, where efficient CO generation at Co sites leads to high local CO concentrations at neighboring Cu sites, thereby favoring C-C coupling and ethanol formation. Operando X-ray absorption spectroscopy reveals a dynamic transformation of the single-site Cu into Cu clusters as actual active sites. In situ infrared spectroscopy reveals the formation of intermediate CO at Co sites, which undergo subsequent spillover and C-C coupling on the Cu clusters. This design concept offers new avenues for noble metal-free tandem electrocatalysts for the conversion of CO2-to-multicarbon products.

The covalent attachment of molecular photosensitizers (PS) to polyoxometalates (POMs) opens new pathways to PS-POM dyads for light-driven charge-transfer and charge-storage. Here, we report a synthetic route for the covalent linkage of BODIPY-dyes to Anderson-type polyoxomolybdates by using CLICK chemistry (i. e. copper-catalyzed azide-alkyne cycloaddition, CuAAC). Photophysical properties of the dyad were investigated by combined experimental and theoretical methods and highlight the role of both sub-components for the charge-separation properties. The study demonstrates how CLICK chemistry can be used for the versatile linkage of organic functional units to molecular metal oxide clusters.

A 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) functionalized phosphaalkene was used as a bidentate ligand towards a [Cu(I)L-2](+) complex. The spectroscopic, electrochemical and photophysical properties of the compound were studied revealing a rich redox chemistry indicative of ligand non-innocence. The compound is weakly emissive with excited state lifetimes of up to 9 ns. NMR and electrochemical analysis indicate a complex dynamic behavior of this photosensitizer in solution.

The new bis(bidentate) tetraphosphane cis,trans,cis‐1,2,3,4‐tetrakis(diphenylphosphanyl)buta‐1,3‐diene (dppbd) (7) was obtained by applying a photochemical synthetic protocol. The key step of the photochemical reaction consisted of an intramolecular [2+2] cycloaddition involving a C–C double and triple bond of the Pt‐dimer species of the formula [Pt2Cl4(dppa)(trans‐dppen)] (2) {dppa = 1,2‐bis(diphenylphosphanyl)acetylene and dppen = 1,2‐bis(diphenylphosphanyl)ethene} leading to [Pt2Cl4(dppbd)] (5). The asymmetrically bridged precursor complex 2 was obtained by combinatorial chemistry. Single crystal X‐ray structure analyses of 2 and 5 proved that the intramolecular photochemical reaction occurred. Cyanolysis of 5 gave 7, which was oxidized to dppbdO4 (8). Compounds 7, 8, and the PdII dimer complex [Pd2Cl4(dppbd)] (9) were characterized in the solid state by a single‐crystal X‐ray structure analysis. Interesting photophysial properties emerged from the UV/Vis spectra acquired for 7 and the dimer Os complexes meso‐Δ,Λ/Λ,Δ‐[Os2(bpy)4(dppbd)](PF6)4 (10) and rac‐Δ,Δ/Λ,Λ‐[Os2(bpy)4(dppbd)](PF6)4 (11).

The Front Cover shows the important steps of the synthesis of dppbd. After the formation of the initial intermediate, comes the second and key step, which is a light induced pericyclic cycloaddition, immediately followed by a thermally induced ring opening reaction. The third step is the removal of platinum, which was used as a template. The last step shows two examples of the coordination of metal centers. In the background is an excitation/emission spectrum of a compound consisting of osmium and the title compound, demonstrating its application as a photosensitizer. More information can be found in the Full Paper by W. Oberhauser, G. Knör, P. Brüggeller et al. For more on the story behind the cover research, see the Cover Profile.