Optimising the acid-base ratio of Mg-Al layered double oxides to enhance CO capture performance: the critical role of calcination conditions.

The effect of calcination conditions (ramp rate, calcination temperature and time) on the formation of MgAl layered double oxides (MgAl LDOs) as well as their CO capture performance, has been systematically investigated. This study explores novel insights into the intricate relationship between these calcination conditions and the resulting surface characteristics, which play a vital role in CO capture efficiency. Notably, it is revealed that a rapid ramp rate (100 °C min) significantly increases surface area and hydroxyl concentration, leading to a 69% increase in CO capture efficiency compared to slower ramp rate.

Coordinative Chain Transfer Polymerization of Butadiene with Functionalized Aluminum Reagents.

Functionalized aluminum alkyls enable effective coordinative chain transfer polymerization with selective chain initiation by the functionalized alkyl. (ω-Aminoalkyl)diisobutylaluminum reagents (12 examples studied) obtained by hydroalumination of α-amino-ω-enes with diisobutylaluminum hydride promote the stereoselective catalytic chain growth of butadiene on aluminum in the presence of Nd(versatate) , Cp* Nd(allyl), or Cp* Gd(allyl) precatalysts and [PhNMe H ]/[B(C F ) ]. Carbazolyl- and indolylaluminum reagents result in efficient molecular weight control and chain initiation by the aminoalkyl rather than the isobutyl substituent bound to aluminum.

Detection and quantification of metastable photoproducts of trenbolone and altrenogest using liquid chromatography-tandem mass spectrometry.

Here, we developed a novel and sensitive method for the detection and quantification of metastable trenbolone and altrenogest photoproducts in agricultural receiving waters based on solid phase extraction (SPE) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Primary method analytes were seven cycloaddition or photohydration transformation products of 17α-trenbolone (17α-TBOH), 17β-trenbolone (17β-TBOH), trendione (TBO), and altrenogest (ALT), which are key contributors to the fate and environmental risks of these steroidal pharmaceuticals. Because commercial analytical standards are not available, reference standards for photoproducts were generated from trenbolone or ALT with a solar simulator (˜6 h, >10 half-lives).

Controlled Polymerization in Polar Solvents to Ultrahigh Molecular Weight Polyethylene.

Novel complexes based on 2,4,8-triarylnaphthylamine [[(2,4-{3,5-(CF)CH}-8-(3,5-RCH)-CH)-N═C(H)-{3-(9-anthryl)-2-O-CH}-κ-N,O]Ni(CH)(pyridine)] (4-Py, R = Me; 5-Py, R = CF) were synthesized from 8-arylnaphthylamines which can be generated via selective lithiation, borylation, and coupling in a one-pot procedure. Due to their living characteristics in ethylene polymerization and the particularly low propensity of 5-Py for β-H elimination as reflected by a high linearity even at elevated polymerization temperatures of 60 °C, ultrahigh molecular weight polyethylene (UHMWPE) is formed in polar organic solvents (THF, diethyl ether) as a reaction medium in a controlled polymerization ( M/ M = 1.2 at M = 1.

Pentafluorosulfanyl Substituents in Polymerization Catalysis.

Highly electron-withdrawing pentafluorosulfanyl groups were probed as substituents in an organometallic catalyst. In Ni(II) salicylaldiminato complexes as an example case, these highly electron-withdrawing substituents allow for polymerization of ethylene to higher molecular weights with reduced branching due to significant reductions in β-hydrogen elimination. Combined with the excellent functional group tolerance of neutral Ni(II) complexes, this suppression of β-hydrogen elimination allows for the direct polymerization of ethylene in water to nanocrystal dispersions of disentangled, ultrahigh-molecular-weight linear polyethylene.