This new mecha-nistic insight has the potential to inform synthetic design strategies for multimetallic energy storage catalysts.įrustrated Lewis pairs (FLPs) have recently been advanced as efficient metal‐free catalysts for catalytic hydrogenation, but their performance in chemoselective hydrogenation, particularly in heterogeneous systems, has not yet been achieved. Differences between the inorganic core’s structural and electronic features outside the protein environment relative to the native CODH cofactor point to a biochemical CO oxidation mechanism that requires a strained active site geometry, with Lewis acid/base frustration enforced by the protein secondary structure. Here we report a W/Cu complex that is the closest synthetic mimic constructed to date, enabled by a silyl protection/deprotection strategy that provided access to a kinetically stabilized complex with mixed O2-/S2- ligation between (bdt)(O)WVI and CuI(NHC) (bdt = benzene dithiolate, NHC = N-heterocyclic carbene) sites. Focusing on four fundamental attributes of any polymerization methodology - mechanism, kinetics, control, and selectivity - this Perspective narrates the growth and development of LPP, tracing each innovation back to fundamental principles so that each concept can be strategically applied, and describes new frontiers fertile for future research.Ĭonstructing synthetic models of the Mo/Cu active site of aerobic carbon monoxide dehydrogenase (CODH) has been a long-standing synthetic challenge thought to be crucial for understanding how atmospheric concentrations of CO and CO2 are regulated in the global carbon cycle by chemolithoautotrophic bacteria and archaea.
Compared to other polymerization methodologies, LPP's cooperative and synergistic two-component catalytic mechanism empowers several unique or advantageous features, including extraordinary tunability of catalyst/initiator systems, compounded thermodynamic and kinetic control over comonomer sequences in one-pot LPP of monomer mixtures for highly resolved block copolymers, complete chemoselectivity in LPP of multifunctional vinyl monomers, independent tuning of polymerization activity and target polymer molecular weight, controlled heat dissipation in bulk polymerization with unactivated monomers functioning as solvent molecules, and coupled selectivity and livingness with immortality of the active species to produce ultrahigh molecular weight polymers and block copolymers with record-number (53) blocks. Ten years have passed since the conception of what was termed Lewis pair polymerization (LPP) that employs Lewis acid and base in pairs to not only activate monomers but also effect chain initiation, propagation, and transfer events. Furthermore, we highlight that SET from the Lewis base to the Lewis acid–substrate adduct may be prevalent in other literature examples of radical FLP chemistry, which provides important design principles for radical main‐group chemistry. In contrast, reaction with TCQ proceeds via SET, which is only feasible by Lewis acid coordination to the substrate. We show that the reactions of H 2 and Ph 3 SnH with archetypal P/B FLP systems do not proceed via a radical mechanism. being direct SET to B(C 6 F 5 ) 3 or not.
Herein, we investigate radical formation upon reacting FLP systems with dihydrogen, triphenyltin hydride or tetrachloro‐1,4‐benzoquinone (TCQ) both experimentally and computationally to determine the nature of the single‐electron transfer (SET) events i.e. Recent reports of radical formation within such systems indicate single‐electron transfer (SET) could play an important role in their chemistry. Frustrated Lewis pairs (FLPs) are well known for their ability to activate small molecules.