Developing more efficient catalysts remains one of the primary targets organometallic chemists. To accelerate reaching this goal, effective molecular descriptors and visualization tools can represent a remarkable aid. Here, we present Web application for analyzing catalytic pocket metal complexes using topographic steric maps as general unbiased descriptor that is suitable every class catalysts. show broad applicability our approach, first compared map series transition presenting popular...

Three types of seemingly unyielding trade-offs have continued to challenge the rational design for circular polymers with both high chemical recyclability and high-performance properties: depolymerizability/performance, crystallinity/ductility, stereo-disorder/crystallinity. Here, we introduce a monomer strategy based on bridged bicyclic thiolactone that produces stereo-disordered perfectly stereo-ordered polythiolactones, all exhibiting crystallinity full recyclability. These polythioesters...

Classical and frustrated Lewis pairs (LPs) of the strong acid (LA) Al(C(6)F(5))(3) with several base (LB) classes have been found to exhibit exceptional activity in pair polymerization (LPP) conjugated polar alkenes such as methyl methacrylate (MMA) well renewable α-methylene-γ-butyrolactone (MBL) γ-methyl-α-methylene-γ-butyrolactone (γ-MMBL), leading high molecular weight polymers, often narrow distributions. This study has investigated a large number LPs, consisting 11 LAs 10 achiral 4...

The bigger the better: new well-defined [Pd(IPr*)(cin)Cl] pre-catalyst is described (see scheme). This complex proves to be highly active in Suzuki–Miyaura cross-coupling for synthesis of tetra-ortho-substituted biaryls under mild conditions. IPr* reported as largest N-heterocyclic carbene (NHC) date [Pd(NHC)(cin)Cl] complexes, explaining high reactivity observed this challenging transformation.

α-Methylene-γ-butyrolactone (MBL), a naturally occurring and biomass-sourced bifunctional monomer, contains both highly reactive exocyclic C═C bond stable five-membered γ-butyrolactone ring. Thus, all previous work led to exclusive vinyl-addition polymerization (VAP) product P(MBL)VAP. Now, this reverses conventional chemoselectivity enable the first ring-opening (ROP) of MBL, thereby producing exclusively unsaturated polyester P(MBL)ROP with Mn up 21.0 kg/mol. This elusive goal was achieved...

This contribution reports the first example of highly selective reduction CO2 into CH4 via tandem hydrosilylation with mixed main-group organo-Lewis acid (LA) catalysts [Al(C6F5)3 + B(C6F5)3] {[Al] [B]}. As shown by this comprehensive experimental and computational study, in unique catalytic process, [Al] effectively mediates step overall cycle, namely fixation HCOOSiEt3 (1) LA-mediated C═O activation, while [B] is incapable promoting same transformation. On other hand, to be an excellent...

Modus operandi: Catalytic access to the title compounds through a new asymmetric α-arylation protocol is reported (see scheme). These products are formed in good yields and excellent enantioselectivities by using easily synthesized chiral N-heterocyclic carbene (NHC) ligand. Advanced DFT calculations reveal properties of NHC ligand mode operation catalyst. Detailed facts importance specialist readers published as "Supporting Information". Such documents peer-reviewed, but not copy-edited or...

Dry reforming of methane (DRM) proceeds via CH4 decomposition to leave surface carbon species, followed by their removal with CO2-derived species. Reactivity tuning for stoichiometric CH4/CO2 reactants was attempted alloying the non-noble metals Co and Ni, which have high affinity CO2 activity decomposition, respectively. This study focused on providing evidence capturing coverage reactive intermediates associated structural changes during DRM at temperature using in-operando X-ray...

A combined theoretical and experimental study shows how weak attractive interactions of a neighboring group can strongly promote chain walking transfer. This accounts for the previously observed very different microstructures obtained in ethylene polymerization by [κ2-N,O-{2,6-(3′,5′-R2C6H3)2C6H3-N═C(H)-(3,5-X,Y-2-O-C6H2)}NiCH3(pyridine)], namely hyperbranched oligomers remote substituents R = CH3 versus high-molecular-weight polyethylene CF3. From full mechanistic consideration, alkyl...

A combined experimental and theoretical study on mechanistic aspects of polymerization conjugated polar alkenes by frustrated Lewis pairs (FLPs) based N-heterocyclic carbene (NHC) Al(C6F5)3 is reported. This consists three key parts: structural characterization active propagating intermediates, propagation kinetics, chain-termination pathways. Zwitterionic intermediates that simulate the species in such have been generated or isolated from FLP activation monomers as 2-vinylpyridine...

Abstract The development of novel and operationally simple synthetic routes to carbene‐metal‐amido (CMA) complexes copper, silver gold relevant for photonic applications are reported. A mild base sustainable solvents allow all reactions be conducted in air at room temperature, leading high yields the targeted compounds even on multigram scales. effect various bases N−H metallation was studied silico experimentally, while a mechanochemical, solvent‐free approach also developed. Our...

Into the groove: The introduction of a C2-symmetric N-heterocyclic carbene ligand with appropriately substituted naphthyl side chains enables efficient Suzuki–Miyaura coupling to form bulky tetra-ortho-substituted biaryls from aryl bromides and chlorides at room temperature. DFT calculations uncover subtle steric phenomena play that lead superior catalytic performance. Cyoct=cyclooctyl. Detailed facts importance specialist readers are published as "Supporting Information". Such documents...

This contribution presents a full account of experimental and theoretical/computational investigations into the mechanisms chain initiation, propagation, termination recently discovered N-heterocyclic carbene (NHC)-mediated organocatalytic conjugate-addition polymerization acrylic monomers. The current study specifically focuses on three commonly used NHCs vastly different nucleophilicity, 1,3-di-tert-butylimidazolin-2-ylidene (ItBu), 1,3-dimesitylimidazolin-2-ylidene (IMes),...

A comparison of the steric properties homogeneous single site catalysts for propene polymerization using percentage buried volume (%VBur) as molecular descriptor is reported. The %VBur calculated on neutral precursors active species seems to be a reliable tool explain several experimental data related insertion and monomer chain transfer. Interestingly, linear correlation between large set energetic difference propagation termination steps by density functional theory (DFT) methods found...

Abstract Extremely slow and extremely fast new water oxidation catalysts based on the Ru–bda (bda=2,2′‐bipyridine‐6,6′‐dicarboxylate) systems are reported with turnover frequencies in range of 1 900 cycles s −1 , respectively. Detailed analyses main factors involved reaction have been carried out a combination reactivity tests, electrochemical experiments, DFT calculations. These give convergent interpretation that generates solid understanding reaction, which turn allows design very low...

Abstract A low‐cost, modular, and easily scalable multicomponent procedure affording access in good yields excellent selectivity (up to 93 %) a wide range of (a)chiral unsymmetrical 1‐aryl‐3‐cycloalkyl‐imidazolium salts is disclosed. Electronic steric properties the corresponding unsaturated N‐heterocyclic carbene (U 2 ‐NHC) ligands were evaluated evidenced strong electron donor ability, high discrimination, modular demand.

Density functional theory (DFT) calculations were used to predict and rationalize the effect of modification structure prototype 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) N-heterocyclic carbene (NHC) ligand. The consists in substitution methyl groups ortho isopropyl substituent with phenyl groups, here we plan describe how such significant changes affect metal environment therefore related catalytic behaviour. Bearing mind that there is a structural difference between both ligands...

A single-step route to telechelic polyethylene (PE) is enabled by selective insertion polymerization. PdII -catalyzed copolymerization of ethylene and 2-vinylfuran (VF) generates α,ω-di-furan polyethylene. Orthogonally reactive exclusively in-chain anhydride groups are formed terpolymerization with carbic anhydride. Combined experimental theoretical DFT studies reveal the key for this direct approach telechelics be a match comonomers' different electronics bulk. Identified essential features...

The search for a low-cost process the valorization of linear α-olefins combining high productivity and selectivity is longstanding goal chemists. Herein, we report soluble ruthenium olefin metathesis catalyst that performs conversion to longer internal olefins with (>99%) under neat conditions at low loadings (50 ppm) without need expensive additives. This robust catalytic allowed us efficiently selectively re-equilibrate naphtha fraction (C5–C8) Fischer–Tropsch feed derived from...

Better catalysts are needed to address numerous challenges faced by humanity. In this Perspective, we review concepts and tools in theoretical computational chemistry that can help accelerate the rational design of homogeneous heterogeneous catalysts. particular, focus on following three topics: (1) identification key intermediates transition states a reaction using energetic span model, (2) disentanglement factors influencing relative stability species energy decomposition analysis...

Bacterial polyhydroxyalkanoates (PHAs) are a unique class of biodegradable polymers because their biodegradability in ambient environments and structural diversity enabled by side-chain groups. However, the biosynthesis PHAs is slow expensive, limiting broader applications as commodity plastics. To overcome such limitation, catalyzed chemical synthesis bacterial has been developed, using metal-catalyzed stereoselective ring-opening (co)polymerization racemic cyclic diolides (rac-8DLR ,...