Recent Advances in the Copolymerization of Ethylene with Polar Comonomers by Nickel Catalysts.

The less-expensive and earth-abundant nickel catalyst is highly promising in the copolymerization of ethylene with polar monomers and has thus attracted increasing attention in both industry and academia. Herein, we have summarized the recent advancements made in the state-of-the-art nickel catalysts with different types of ligands for ethylene copolymerization and how these modifications influence the catalyst performance, as well as new polymerization modulation strategies. With regard to α-diimine, salicylaldimine/ketoiminato, phosphino-phenolate, phosphine-sulfonate, bisphospnine monoxide, -heterocyclic carbene and other unclassified chelates, the properties of each catalyst and fine modulation of key copolymerization parameters (activity, molecular weight, comonomer incorporation rate, etc.

Precipitation Polymerization: A Powerful Tool for Preparation of Uniform Polymer Particles.

Precipitation polymerization (PP) is a powerful tool to prepare various types of uniform polymer particles owing to its outstanding advantages of easy operation and the absence of any surfactant. Several PP approaches have been developed up to now, including traditional thermo-induced precipitation polymerization (TRPP), distillation precipitation polymerization (DPP), reflux precipitation polymerization (RPP), photoinduced precipitation polymerization (PPP), solvothermal precipitation polymerization (SPP), controlled/''living'' radical precipitation polymerization (CRPP) and self-stabilized precipitation polymerization (2SPP). In this review, a general introduction to the categories, mechanisms, and applications of precipitation polymerization and the recent developments are presented, proving that PP has great potential to become one of the most attractive polymerization techniques in materials science and bio-medical areas.

Enhancing Ethylene Polymerization of -Cobalt(II) Precatalysts Adorned with a Fluoro-substituent.

Unsymmetrical 2-(1-(2,4-dibenzhydryl-6-fluorophenylimino)ethyl)-6-(1-alkylphenyl-imino)ethyl)pyridine compounds (Ar = 2,6-MeCH in ; 2,6-EtCH in ; 2,6- PrCH in ; 2,4,6-MeCH in ; 2,6-Et-4-Me-CH in ) were prepared and characterized. The treatment of CoCl with the compounds - afforded the corresponding cobalt complexes - in excellent yields. The molecular structures of and were determined by single-crystal X-ray diffraction, revealing the distorted-square-pyramidal geometry with three nitrogen atoms and two chlorine atoms around the cobalt center.

Simulated Patient Role-Plays with Consumers with Lived Experience of Mental Illness Post-Mental Health First Aid Training: Interrater and Test Re-Test Reliability of an Observed Behavioral Assessment Rubric.

Mental Health First Aid (MHFA) training teaches participants how to assist people experiencing mental health problems and crises. Observed behavioral assessments, post-training, are lacking, and the literature largely focuses on self-reported measurement of behaviors and confidence. This study explores the reliability of an observed behavioral assessment rubric used to assess pharmacy students during simulated patient (SP) role-play assessments with mental health consumers.

4,4'-Difluorobenzhydryl-modified bis(imino)-pyridyliron(ii) chlorides as thermally stable precatalysts for strictly linear polyethylenes with narrow dispersities.

The 4,4'-difluorobenzhydryl-modified bis(imino)pyridylferrous chlorides, [2-{CMeN(2,6-(4-FC6H4)2CH2-4-t-BuC6H2)}-6-(CMeNAr)C5H3N] FeCl2 (Ar = 2,6-Me2C6H3Fe1, 2,6-Et2C6H3Fe2, 2,6-i-Pr2C6H3Fe3, 2,4,6-Me3C6H2Fe4, 2,6-Et-4-MeC6H2Fe5 and 2,6-(4-FC6H4)2CH2-4-t-BuC6H2Fe6), were synthesized in good yields. All iron complexes were characterized by 1H/19F NMR and elemental analysis, and the molecular structures of representative complexes Fe1 and Fe6 were determined by single crystal X-ray diffraction, which revealed a slightly distorted square pyramid around the iron center. Activated with either MAO or MMAO, Fe1-Fe5 exhibited very high activities (up to 17.

Sterically and Electronically Modified Aryliminopyridyl-Nickel Bromide Precatalysts for an Access to Branched Polyethylene with Vinyl/Vinylene End Groups.

A series of 2-((arylimino)ethyl)pyridine derivatives (), each containing -2,4-bis(dibenzocycloheptyl) groups with variations in the steric/electronic properties of the ortho-substituent in the aryl ring, and the corresponding nickel bromide precatalysts [2-N{2,4-(CH)-6-R-CH}CHN]NiBr (R = Me (), Et (), Pr (), Cl (), or F ()), have been prepared in high yield. All the precatalysts are air-stable and characterized by Fourier transform infrared spectroscopy and elemental analysis. The molecular structures of and were proved through single-crystal X-ray diffraction analysis.

Steric and electronic modulation of iron catalysts as a route to remarkably high molecular weight linear polyethylenes.

Five structurally related bis(arylimino)pyridine-iron(ii) chloride complexes, [2-[CMeN{2,6-{(4-FC6H4)2CH}2-4-NO2}]-6-(CMeNAr)C5H3N]FeCl2 (Ar = 2,6-Me2C6H3Fe1, 2,6-Et2C6H3Fe2, 2,6-i-Pr2C6H3Fe3, 2,4,6-Me3C6H2Fe4, and 2,6-Et2-4-MeC6H2Fe5), incorporating one N-2,6-bis{di(4-fluorophenyl)methyl}-4-nitrophenyl group and one distinct N-aryl group, have been prepared in good yield through the interaction of the corresponding free ligands (L1-L5) with FeCl2·4H2O. All ferrous complexes were paramagnetic which was manifested by broad and highly shifted peaks in their 1H NMR spectra. The marked steric imbalance imposed by the two inequivalent N-aryl groups was a key feature highlighted in the molecular structures of representative complexes Fe1 and Fe2.

1,5-Naphthyl-linked bis(imino)pyridines as binucleating scaffolds for dicobalt ethylene oligo-/polymerization catalysts: exploring temperature and steric effects.

Six examples of dinuclear bis(imino)pyridine-cobalt(ii) complexes, [1,5-{2-(CMe[double bond, length as m-dash]N)-6-(CMe[double bond, length as m-dash]N(2,6-R-4-R-CH))CHN}(CH)]CoCl (R = Me, R = H Co1; R = Et, R = H Co2; R = Pr, R = H Co3; R = Me, R = Me Co4; R = Et, R = Me Co5; R = CHPh, R = Me Co6), have been prepared from the corresponding bis(tridentate) compartmental ligands (L1-L6) in reasonable yields. The molecular structures of Co3 and Co5 revealed two N,N,N-cobalt dichloride units to adopt anti-positions about the 1,5-naphthyl linking unit, with each cobalt center exhibiting a distorted trigonal bipyramidal geometry. On activation with either MAO or MMAO, Co1-Co6 were shown to promote both polymerization and oligomerization of ethylene with high overall activities (up to 1.

gem-Dimethyl-substituted bis(imino)dihydroquinolines as thermally stable supports for highly active cobalt catalysts that produce linear PE waxes.

Six types of 2,8-bis(imino)-7,7-dimethyl-5,6-dihydroquinoline, 2-(ArN[double bond, length as m-dash]CMe)-8-(ArN)-7,7-MeCHN (Ar = 2,6-MeCHL1, 2,6-EtCHL2, 2,6-PrCHL3, 2,4,6-MeCHL4, 2,6-Et-4-MeCHL5, 2,4,6-BuCHL6), distinguishable by their steric and electronic profile, are described that can readily undergo complexation with cobaltous chloride to form their corresponding LCoCl chelates, Co1-Co6. The molecular structures of Co2 and Co3 reveal square pyramidal geometries with ring puckering a feature of the gem-dimethyl section of their unsymmetrical N,N,N'-ligands. On activation with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), all the cobalt complexes exhibited exceptionally high activities for ethylene polymerization with levels reaching up to 1.

Plastomeric-like polyethylenes achievable using thermally robust N,N'-nickel catalysts appended with electron withdrawing difluorobenzhydryl and nitro groups.

A new set of five unsymmetrical N,N'-diiminoacenaphthenes, 1-[2,6-{(4-FCH)CH}-4-NOCHN]-2-(ArN)CCH (Ar = 2,6-MeCHL1, 2,6-EtCHL2, 2,6-PrCHL3, 2,4,6-MeCHL4, 2,6-Et-4-MeCHL5), have been synthesized and used to prepare their corresponding nickel(ii) halide complexes, LNiBr (Ni1-Ni5) and LNiCl (Ni6-Ni10). The molecular structures of Ni3(OH) and Ni4 reveal distorted square pyramidal and tetrahedral geometries, respectively, while the H NMR spectra of all the nickel(ii) (S = 1) complexes show broad paramagnetically shifted peaks. Upon activation with either methylaluminoxane (MAO) or ethylaluminum sesquichloride (EtAlCl, EASC), Ni1-Ni10 displayed very high activities for ethylene polymerization with the optimal performance being observed using 2,6-dimethyl-containing Ni1 in combination with EASC (1.

Adsorption of chloro-anilines from solution by modified peanut husk in fixed-bed column.

Natural peanut husk (NPH) modified with hexadecyl trimethyl ammonium bromide (CTAB) was used as adsorbent to remove 2,5-dimethoxy-4-chloroaniline (DMCH) from solution in a fixed-bed column. Fourier transform infrared spectroscopy analysis and X-ray fluorescence of NPH and modified peanut husk (MPH) showed that CTAB had been introduced onto the surface of NPH. The effects of flow rate and bed depth on breakthrough curves were studied.