The Stronger the Better: Donor Substituents Push Catalytic Activity of Molecular Chromium Olefin Polymerization Catalysts was written by Hansen, Helge-Boj;Wadepohl, Hubert;Enders, Markus. And the article was included in Chemistry – A European Journal in 2021.Quality Control of 4-Methoxy-2-methylpyridine This article mentions the following:
The donor strength of bifunctional pyridine-cyclopentadienyl ligands was altered systematically by the introduction of donating groups in the para-position of the pyridine. In the resulting chromium complexes an almost linear correlation between donor strength and the nitrogen-chromium distance as well as the electronic absorption maximum is exptl. observed The connection of electron-donating groups in the ligand backbone leads to an efficient transfer of the electronic influences to the catalytically active metal center without restricting it through steric effects. Therefore, catalytic olefin polymerization activity, which is already very high for the previously studied catalysts, increase considerably by attaching para-amino groups to the chelating pyridine or quinoline, resp. Combining electron-rich indenyl ligands with para-amino substituted pyridines lead to the highest catalytic activities observed so far for this class of organo chromium olefin polymerization catalysts. The resulting polymers are of ultra-high mol. weight and the ability of the catalysts to incorporate co-monomers is also very high. In the experiment, the researchers used many compounds, for example, 4-Methoxy-2-methylpyridine (cas: 24103-75-1Quality Control of 4-Methoxy-2-methylpyridine).
4-Methoxy-2-methylpyridine (cas: 24103-75-1) belongs to pyridine derivatives. In contrast to benzene, Pyridine’s electron density is not evenly distributed over the ring, reflecting the negative inductive effect of the nitrogen atom. Pyridine, its benzo and pyridine-based compounds play diverse roles in organic chemistry. Pyridine-based materials are valued for their optical and physical properties as well as their medical potential. Quality Control of 4-Methoxy-2-methylpyridine