Pyrazolyl iron, cobalt, nickel, and palladium complexes: synthesis, molecular structures, and evaluation as ethylene oligomerization catalysts

Pyrazolyl‐phosphinoyl nickel (II) complexes: synthesis, characterization and ethylene dimerization studies

“…Similar trends were also observed for others phosphinoyl-coordinated nickel complexes already described in the literature. The Ni(1)-N(2) bond distance [2.1841(12) Å] is close to the values previously reported for Ni (II) complexes containing pyrazolyl ligands, [8,13,[31][32][33][34] and the average Ni(1)-O(1) bond distance [2.0437(9) Å] is similar to that previously reported for others nickel-phosphinoyl complexes. The molecular structure of Ni1 is shown in Figure 3 and the main crystallographic data and structure refinement parameters are reported in Table 1.…”

“…[4,5] Besides the choice of the metal center, various bi-and tridentate chelating ligands have been used to assist the generation and stabilization of the catalytically active specie. [7][8][9][10][11][12][13][14] Among the classes of pyrazolyl ligands, special attention has been devoted to those ones functionalized with different donor groups, mainly due to the structural diversity and ability to provide unusual and particular chemical reactivity. [6] In particular, pyrazolyl-based ligands and their metal complexes have been widely studied and applied in organometallic chemistry and homogeneous catalysis.…”

(Pyrazolyl)-(phosphinoyl)pyridine iron(II), cobalt(II) and nickel(II) complexes: Synthesis, characterization and ethylene oligomerization studies

“…This finding was only preceded by another report by Dyer and co-workers, even though the extent of FriedeleCrafts alkylation was minimal in their system [18]. Following this discovery, we have extensively studied FriedeleCrafts alkylation reactions [8,9,16] to establish the role of the catalyst structure, solvent and nature of co-catalysts in controlling product distribution. From our accounts, in addition to literature reports, it is apparent that the pyrazolyl ligand plays a major role in promoting FriedeleCrafts alkylation of the pre-formed oligomers.…”

Synthesis, characterization and antimicrobial activity of 5‐(arylazo)salicylaldimines and their copper(II) complexes

“…For instance, metal Schiff base complexes catalyse oxidation, aziridination, cyclopropanation, polymerization, epoxidation and hetero‐Diels–Alder reactions. Also, Schiff base metal complexes are an important class of bioactive compounds as they exhibit good molluscicidal, antimicrobial, antimalarial and other biological activities …”