Oxidative alkylation of (η5-C5Me5)2TiR (R = Cl, Me, Et, CH=CH2, Ph, OMe, N=C(H)tBu) to (η5-C5Me5)2Ti(Me)R by group 12 organometallic compounds MMe2

Oxidative alkylation of Cp*2TiX (Cp*: η5-C5Me5; X = OMe, Cl, N=C(H)tBu) and Cp* 2TiMe by CdMe2 or ZnMe2 gives diamagnetic Cp*2Ti(Me)X and Cp*2TiMe2 respectively, and cadmium or zinc. The reactions of Cp*2TiR (R = Et, CH=CH2, Ph) with MMe2 (M = Cd, Zn) give statistical mixtures of Cp*2Ti(Me)R, Cp*2TiMe2 and Cp*2TiR2. Dimethylmercury does not react with Cp*2TiX.

High temperature fluidized bed pyrolysis of different polyethylene structures to investigate the gas phase composition

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Mechanism and stereochemistry for nucleophilic attack at carbon of platinum(IV) alkyls: model reactions for hydrocarbon oxidation with aqueous platinum chlorides

We and others have recently confirmed the original reports by Shilov that aqueous solutions of a mixture of [PtCl_4]^(2-) and [PtCl_6]^(2-) are capable of functionalizing the C-H bonds of substrates including methane, initially producing a mixture of alcohols and alkyl chlorides. The working mechanistic scheme invokes the following general features: (1) electrophilic C-H activation to generate a platinum(I1) alkyl, (2) oxidation to a platinum(1V) alkyl, and (3) nucleophilic attack by water or chloride, displacing platinum(II) and generating the product alcohol or alkyl chloride. In this article we report the preparation, isolation, and characterization of methyl and β-hydroxyethyl derivatives of chloroplatinum(IV) along with the results of our investigations of the mechanism for nucleophilic attack by water or chloride. The rates and stereochemistry provide some of the first firm support for the latter stages of this working mechanistic scheme

Synthesis and thermolysis of Cp*(C5Me4CH2)TiR complexes

Substitution of the chloride in Cp*FvTiCl with MR (Fv = C5Me4CH2; R = Me, CH2SiMe3, CH2CMe3, CH = CH2, M = Li; R = CH2Ph, M = K; R = C3H5, M = MgCl; R = Ph, M = Na . NaCl) gives Cp*FvTiR. NMR spectroscopic evidence points towards a series of structurally related compounds with a bent-sandwich geometry. The substituent R is positioned in the wedge, midway below the exocyclic methylene group and a neighbouring methyl group of the fulvene. Thermolysis of Cp*FvTiR gives, dependent on the substituent R, reduction to Cp*FvTi (R = CH2Ph) or the double ring metallated Cp*[C5Me3(CH2)(2)]Ti (R = CH2XMe3, X = C, Si) or Cp*FvTiCH=CHMe (R = eta(3)-C3H5)

Mechanism and stereochemistry for nucleophilic attack at carbon of platinum(IV) alkyls: model reactions for hydrocarbon oxidation with aqueous platinum chlorides

We and others have recently confirmed the original reports by Shilov that aqueous solutions of a mixture of [PtCl_4]^(2-) and [PtCl_6]^(2-) are capable of functionalizing the C-H bonds of substrates including methane, initially producing a mixture of alcohols and alkyl chlorides. The working mechanistic scheme invokes the following general features: (1) electrophilic C-H activation to generate a platinum(I1) alkyl, (2) oxidation to a platinum(1V) alkyl, and (3) nucleophilic attack by water or chloride, displacing platinum(II) and generating the product alcohol or alkyl chloride. In this article we report the preparation, isolation, and characterization of methyl and β-hydroxyethyl derivatives of chloroplatinum(IV) along with the results of our investigations of the mechanism for nucleophilic attack by water or chloride. The rates and stereochemistry provide some of the first firm support for the latter stages of this working mechanistic scheme

Disentangled UHMWPE@silica powders for potential use in power bed fusion based additive manufacturing

Disentangled ultrahigh molecular weight polyethylene dUHMWPE (Mw ∼ 2.106 Da) particles in a reactor blend with HDPE are catalytically prepared from ethylene, mediated by a new catalyst from N,N'-(2,6-pyridinediyl diethylidyne) bis[2,6-di-3-propenyl-benzenamine] iron dichloride and triethyl aluminum. These particles could be laser sintered, but not automatically processed in an SLS machine. The same catalyst supported on microsilica particles gives access to composite dUHMWPE@silica particle powder with particle sizes below 200 µm. Testing bars prepared by heat pressing have an Emod of 150 MPa, an elongation at break at 450 % and an ultimate strength of 39 ± 11 MPa. A SEM image indicates a silica induced crystallization into pseudo spherulites of 500 µm size. The dUHMWPE@silica composite particles have an fcc flowability value of 3.4 in a ring shear tester, and a low density of 150 kg.m−3. Additivation with nanosilica powder (1 wt%) and carbon black (0.25 wt%) allowed to process the composite in an SLS machine. The printed parts showed severe caking, but also a complete welding of the powder, albeit with voids on account of the low particle density