In an article, author is Milani, Jorge L. S., once mentioned the application of 2075-46-9, Recommanded Product: 2075-46-9, Name is 4-Nitro-1H-pyrazole, molecular formula is C3H3N3O2, molecular weight is 113.08, MDL number is MFCD00159626, category is pyrazoles-derivatives. Now introduce a scientific discovery about this category.
Chromium Complexes Supported by Phenyl Ether-Pyrazolyl [N,O] Ligands as Catalysts for the Oligo- and Polymerization of Ethylene
A new series of Cr (III) complexes [Cr{1-(3-phenoxypropyl)-1H-pyrazole}Cl-3](2)(Cr1),[Cr{1-(3-phenoxypropyl)-3,5-dimethyl-1H-pyrazole}Cl-3](2)(Cr2), and [Cr{1-(3-phenoxypropyl)-3-phenyl-1H-pyrazole}Cl-3](2)(Cr3)have been synthesized and characterized by elemental analysis, high-resolution mass spectrometry (HRMS) and IR spectroscopy. Upon activation with methylaluminoxane (MAO), chromium precatalystsCr2andCr3showed moderate activity in ethylene oligomerization [TOF = 17,900-29,200 mol (ethylene).mol (Cr)(-1).h(-1)at 80 degrees C] with Schultz-Flory distribution of oligomers (K= 0.54-0.66) and production of polymer varying from 2.8 to 6.7 wt.%. On the other hand, under identical oligomerization conditions,Cr1/MAO behaved as a polymerization catalyst generating predominantly polyethylene (63.7 wt%). The amount of 1-butene is the largest component in the liquid fraction suggesting that these precatalysts operate via a Cossee-Arlman mechanism. The catalytic activities, selectivity and product distribution are quite sensitive to the R-group at the 3- and 5-position of the pyrazolyl ring. Based on the electronic and steric effects of R- substituents, it is possible to stablish a trend of activity:Cr2(Pz(Me2)) >Cr3(Pz(Ph)) >Cr1(Pz). Moreover, the effect of oligomerization parameters (cocatalyst, temperature, [Al]/[Cr] molar ratio, time) on the activity and on the product distribution were examined.
If you are interested in 2075-46-9, you can contact me at any time and look forward to more communication. Recommanded Product: 2075-46-9.
Reference:
Pyrazole – Wikipedia,
,Pyrazoles – an overview | ScienceDirect Topics