A donor-acceptor polymer semiconductor, PDQT, comprising diketopyrrolopyrrole (DPP) and β-unsubstituted quaterthiophene (QT) for organic thin film transistors (OTFTs) is reported. This forms ordered layer-by-layer lamellar packing with an edge-on orientation in films even without thermal annealing. The strong intermolecular interactions arising from the fused aromatic DPP moiety DPP-QT interaction facilitate spontaneous self-assembly of chains into close proximity form a large π-π overlap,...

The bis(imino)pyridine iron complex, [[2,6-(MeC=N-2,6-iPr2C6H3)2C5H)N]FeCl2] (1), in combination with MAO and ZnEt2 (> 500 equiv.), is shown to catalyze polyethylene chain growth on zinc. catalyzed process characterized by an exceptionally fast reversible exchange of the growing polymer chains between zinc centers. Upon hydrolysis resultant ZnR2 product, a Poisson distribution linear alkanes obtained; alpha-olefins can be generated via nickel-catalyzed displacement reaction. Other...

Highly active transition metal ethylene polymerization catalysts across the series have been investigated for their ability to catalyze chain growth on zinc. In reactions of various with ZnEt2, product distributions range from Schulz−Flory Poisson, several showing intermediate behavior. A statistical modeling program is introduced correlate relative rates propagation, transfer zinc, and β-H transfer. Six regimes identified, ranging pure Poisson where only termination process, through...

Bis(imino)pyridineiron complexes are not only highly active for ethylene polymerization, they shown to catalyze efficient polyethylene chain growth at zinc centers—formally an iron-catalyzed Aufbaureaktion on (see scheme). The grown alkyl chains can be displaced from the centers by olefin exchange reaction catalyzed by, example, [Ni(acac)2] (acac=acetylacetonate) give linear α-olefins with a Poisson distribution.

A series of co-oligomerization and copolymerization reactions C2H4/C2D4 (1:1) mixtures have been carried out using various transition metal catalysts based on Cr, Co, Fe in combination with MAO. The oligomeric α-olefin products analyzed by GC GC/MS, the experimental results compared theoretical mass spectra derived from mathematical models. Solid polymer samples 13C{1H} 13C DEPT-135 NMR spectroscopy. can be used as a method to differentiate between metallacyclic or Cossee-type chain growth...

The synthesis and characterization of bulky diphosphine 1,2-bis(4-phosphorinone)xylene, BPX, its palladium complexes [(BPX)PdCl2] [(BPX)Pd(O2CCF3)2] are described. BPX was evaluated as a ligand in Pd-catalyzed isomerizing methoxycarbonylation. A broad range alkenes, including terminal, internal, branched, functionalized can be converted to esters with activities selectivities matching or surpassing the performance state-of-the-art bis(di(tert-butyl)phosphino-o-xylene (Pd-DTBPX) catalyst....

The hydrogenation of C1 feedstocks (CO and CO2) has been investigated using ruthenium complexes [RuHCl(CO)(PN3P)] as the catalyst. PN3P pincer ligands containing amines in linker between central pyridine donor phosphorus donors with bulky substituents (tert-butyl (1) or TMPhos (2)) are required to obtain mononuclear single-site catalysts that can be activated by addition KOtBu generate stable five-coordinate [RuH(CO)(PN3P–H)], whereby ligand deprotonated. Activation hydrogen takes place via...

A series of sterically bulky diphosphines have been prepared, including P2 = trans-1,2-bis[(di-tert-butylphosphino)methyl]cyclohexane (4), (2-methylenepropane-1,3-diyl)bis(di-tert-butylphosphine) (5), bis[(di-tert-butylphosphino)methyl]dimethylsilane (6), and cis- trans-11,12-bis[(di-tert-butylphosphino)methyl]-9,10-dihydro-9,10-ethanoanthracene (10 11). The corresponding palladium complexes these ligands, P2Pd(CF3CO2)2, synthesized characterized. solid-state structures [Pd(4)(CF3CO2)2],...

Abstract The acid catalyzed reactive distillation of γ‐valerolactone yields pentenoic acids (PEAs) which can be obtained in >90 % purity and >97 selectivity. PEAs (five isomers) converted into a number useful products with commercial relevance. hydroxycarbonylation adipic (a Nylon monomer) very high selectivity good activity. Self‐metathesis C6 – C8 unsaturated dicarboxylic after hydrogenation produces mixture acid, pimelic suberic acid. If the are first subjected to ethenolysis;...

The palladium-catalyzed conversion of (bio)pentenoic acid isomers (PEAs) occurs with high activity and selectivity to adipic (ADA) in the presence diphosphine ligand L2 = 1,2-bis[(di-tert-butyl)phosphinomethyl]benzene (DTBPX) an cocatalyst. Using density functional theory (DFT) calculations, we show that active catalyst ([L2PdII-H]+) isomerizes PEAs their equilibrium mixture, from which selective carbonylation hydrolysis results ADA product. Hydrolysis is rate-limiting also...

Nicht nur hoch aktiv bei der Ethylenpolymerisation sind Bis(imino)pyridin-Eisen-Komplexe, sie katalysieren auch effizientes Kettenwachstum an Zinkzentren – formal eine eisenkatalysierte Aufbaureaktion am Zink (siehe Schema). Die erhaltenen Alkylketten können von den durch Olefinaustauschreaktion verdrängt werden, die z. B. [Ni(acac)2] (acac=Acetylacetonat) katalysiert werden kann. Hierdurch wird ein Gemisch linearer α-Olefine mit einer Poisson-Verteilung erhalten.

Abstract (11b R ,11′b )‐4,4′‐(1,2‐Phenylene)bis[4,5‐dihydro‐3 H ‐dinaphtho[2,1‐ c :1′,2′‐ e ]phosphepin] [abbreviated as ( )‐BINAPHANE], (3 ,3′ ,4 S ,4′ ,11b )‐4,4′‐bis(1,1‐dimethylethyl)‐4,4′,5,5′‐tetrahydro‐3,3′‐bi‐3 ]phosphepin [( )‐BINAPINE], (1 ,1′ ,2 ,2′ )‐1,1′‐bis(1,1‐dimethylethyl)‐2,2′‐biphospholane S,S,R,R )‐TANGPHOS] and (2 ,5 ,5′ )‐1,1′‐(1,2‐phenylene)bis[2,5‐bis(1‐methylethyl)phospholane] R,R ) ‐i‐ Pr‐DUPHOS] are C 2 ‐bridged chiral diphosphines that form stable complexes with...

Bis(imino)pyridines 2-[2,6-(R1)2C6H3N═C(CH3)]-6-[2,6-(R2)2C6H3N═C(CH3)](C5H3N) (1a, R1 = R2 i-Pr; 1b, i-Pr, CH3; 1c, CH3) were first alkylated by AlMe3 and then hydrolyzed to aminoiminopyridines 2-[2,6-(R1)2C6H3N═C(CH3)]-6-[2,6-(R2)2C6H3NHC(CH3)2](C5H3N) (3a, 3b, 3c, CH3). When the treated with AlMe3, expected methane elimination was not found; alkylation at imine functional group led aluminum complexes {2-[2,6-(R1)2C6H3NC(CH3)2]-6-[2,6-(R2)2C6H3NHC(CH3)2](C5H3N)}AlMe2 (4a, 4b, 4c, CH3),...

The melt-phase polymerization of bisphenol A (BPA) and diphenyl carbonate (DPC) catalyzed by alkaline metal catalysts produces polycarbonates with high branching, which impairs the product's properties during weather resistance, ductility, rheology. use an imidazolium-type catalyst can result in a reduced amount branching relative to benchmark Cs2CO3 catalyst. Modification imidazolium structure, especially introducing substitution at C2 position, definitely improves performance enhancing...

Tetramethyldisilazane-bridged closo-carborane compounds, [(closo-1-R-1,2-C2B10H10)Me2Si]2NH (R = Me (1), Ph (2)), and their tantalum complexes, [(closo-2-R-2,3-C2B10H10)Me2Si]2N]Ta(V) (3), (4)), have been prepared characterized. Compounds 3 4 were found to be active catalysts for the polymerization of ethylene in presence cocatalyst MAO produce two morphologically different polyethylenes with high molecular weight.

Cyclopentene hydroformylation, both stoichiometric and catalytic, is performed starting with Rh4(CO)12 CpW(CO)3H as precursors. Synergism observed. Isotopic labeling experiments confirm 30% of the product formation occurs via a catalytic binuclear elimination reaction. Two new intermediates are spectroscopically identified using band target entropy minimization DFT, namely, RhW(CO)7Cp CpW(CO)3H-C5H9CORh(CO)4. The latter intermediate appears to be hydrogen bonded two simultaneous...

Nicht nur hoch aktiv bei der Ethylenpolymerisation sind Bis(imino)pyridin-Eisen-Komplexe, sie katalysieren auch effizientes Kettenwachstum an Zinkzentren – formal eine eisenkatalysierte Aufbaureaktion am Zink (siehe Schema). Die erhaltenen Alkylketten können von den durch Olefinaustauschreaktion verdrängt werden, die z. B. [Ni(acac)2] (acac=Acetylacetonat) katalysiert werden kann. Hierdurch wird ein Gemisch linearer α-Olefine mit einer Poisson-Verteilung erhalten.

A series of palladium complexes with C3-bridged bidentate bis(diphenylphosphino)propane ligands substituents varying steric bulk at the central carbon have been synthesized. The size gem-dialkyl affects C–C–C bond angles within and consequently P–M–P ligand bite angles. combination solid-state X-ray diffraction (XRD) density functional theory (DFT) studies has shown that an increase in substituent results a distortion 6-membered metal–ligand chair conformation toward boat conformation, to...

Phenylene-bridged diphobane ligands with different substituents (CF3, H, OMe, (OMe)2, tBu) have been synthesized and applied as in palladium-catalyzed carbonylation reactions of various alkenes. The performance these terms selectivity hydroformylation versus alkoxycarbonylation has studied using 1-hexene, 1-octene, methyl pentenoates substrates, the results compared ethylene-bridged ligand (BCOPE). Hydroformylation 1-octene protic solvent 2-ethyl hexanol a competition between...

High-melt-strength (HMS) polypropylene (PP) has enabled easy supercritical-CO2 (scCO2) foaming of PP. However, producing microcellular PP foams via simple scCO2 extrusion still remains challenging, whereas macrocellular with high expansion ratios (ER) generally exhibit poor mechanical strengths. In this study, to simultaneously enhance both ER and compressive strengths foams, a type low-cost Janus molecules, heptaisobutyl open-cage silsesquioxane (HOS), is incorporated into HMS-PP. Since HOS...

Reaction of the amido-bridged zirconium complex (CpSiMe(2)NSiMe(2)Cp)ZrCH(3) (1) (Cp = C(5)H(4)) with half an equivalent B(C(6)F(5))(3) or Ph(3)CB(C(6)F(5))(4) afforded binuclear complexes [(CpSiMe(2)NSiMe(2)Cp)Zr)(2)(mu-CH(3))][RB(C(6)F(5))(3)] (2a, R CH(3), 2b, C(6)F(5)) a methyl group as bridge between two atoms. In presence one Ph(3)C(C(6)F(5))(4), 1 was transformed to zwitterionic [(CpSiMe(2)NSiMe(2)Cp)Zr][RB(C(6)F(5))(3)] (3a, 3b, which are free metal-bound sigma-alkyl ligand. 2b is...

The new tridentate ligand CpSiNSiCp and its zirconium complexes have been prepared. These complexes, containing two constrained-geometry units that are linked together via the N−Zr bond in each molecule, active catalysts for olefin polymerization when activated with MAO or B(C6F5)3.

Secondary phosphines are important building blocks in organic chemistry as their reactive P-H bond enables construction of more elaborate molecules. In particular, they can be used to construct tertiary that have widespread applications organocatalysts, and ligands metal-complex catalysis. We report here a practical synthesis the bulky secondary phosphine synthon 2,2,6,6-tetramethylphosphinane (TMPhos). Its nitrogen analogue tetramethylpiperidine, known for over century, is base chemistry....