In traditional cross-coupling reactions, a three-step catalytic cycle mechanistically based on 2-electron processes is employed: oxidative addition of a halide at PdÂº or NiÂº, transmetalation of an organometallic nucleophile with the oxidative addition intermediate, and reductive elimination, which releases the coupled product and regenerates the Pd0 or NiÂº catalyst.
One of the grand challenges facing humanity today is access to sustainable materials and chemicals which are at the heart of sustainable technologies. The production of materials, chemicals and fuels from abundant and renewable resources will eliminate our dependence on petroleum/critical metal based supplies and will provide access to a new economy based on available reserves.
Lead halide perovskites have been demonstrated as high performance materials in solar cells and light-emitting devices. These materials are characterized by coherent band transport expected from crystalline semiconductors, but dielectric responses and phonon dynamics typical of liquids. This “crystal-liquid” duality implies that lead halide perovskites belong to phonon glass electron crystals, a class of materials believed to make the most efficient thermoelectrics.
It will be shown that the peculiar electronic and steric properties of cyclic (alkyl)(amino)carbenes (CAACs) (1,2) and other stable singlet carbenes allow for the stabilization of unusual diamagnetic and paramagnetic main group element species. As examples, we will describe the preparation of room temperature stable boron, antimony-, and even carbon-centered neutral and cationic radicals. We will also show that CAACs allow for the isolation of catalytically active complexes, which were supposed to be only transient intermediates.