One of the most efficient and versatile ways to synthesize polyolefin nanocomposites is the in-situ polymerization of olefins in the presence of nano particles by metallocene catalysts. Metallocene/methylaluminoxane (MAO) catalysts are soluble in hydrocarbons and therefore they can be absorbed perfectly in solution onto the surface of particles or fibers and after addition of ethene or propene ...

Both metallocene and Phillips chromium catalysts are used in the commercial manufacture of polyethylene. Unlike most other systems, Chevron Chemical (CPC) platform does not use methylaluminoxane or fluoroorganic boranes. Instead, support itself serves to activate (ionize) metallocenes, which then polymerize ethylene at high activity. Most these solid acid supports can also be anchor Cr make a c...

When triisobutylaluminum (AliBu(3)) is added to solutions containing methylaluminoxane (MAO) and rac-[Me(2)Si(ind)(2)ZrCl(2)] (ind: indenyl) in C(6)D(6), NMR spectra show that methyl-bridged mixed-alkylaluminum dimers Al(mu-Me)(2)Me(4-x)iBu(x) predominate. These dimers react with MAO under partial transfer of isobutyl groups and induce a conversion of the initially prevailing cationic trimethyl...

Current heterogeneous catalysts lack the fine steric and electronic tuning required for catalyzing the selective dimerization of ethylene to 1-butene, which remains one of the largest industrial processes still catalyzed by homogeneous catalysts. Here, we report that a metal-organic framework catalyzes ethylene dimerization with a combination of activity and selectivity for 1-butene that is pre...

A series of titanium and zirconium complexes with ligands based on di-isopropyl phosphorus-phenylamine and their derivatives were synthesized and characterized. These catalysts were utilized to catalyze the copolymerization of ethylene with N-acetyl-O-(dec-9-enyl)-L-tyrosine ethyl ester with high catalytic activity of 6.63 × 104 g P (mol Ti)−1 h−1 after activation by methylaluminoxane (MAO). Th...

New titanium(IV) complexes having two bidentate β-iminoethyl-spiro[4,5]decan-6-onato ligands with various N-aryl substituents have been synthesized. X-ray crystal structure analysis reveals that these titanium complexes all exhibit a C2-symmetric conformation with a distorted octahedral geometry, although the specific orientation of the ligands around the titanium center varies with the identit...

Ambient ionization mass spectrometry is achieved in a simple manner by loading a sample solution onto a corner of a microscope cover glass positioned in front of the inlet to a mass spectrometer and applying a high voltage to the sample. The resulting stream of charged droplets is stable, has no contamination from the substrate platform, and can be used repeatedly. The utility of droplet spray ...