Duan, Yu-Lai published the artcileZirconium and hafnium complexes bearing pyrrolidine derived salalen-type {ONNO} ligands and their application for ring-opening polymerization of lactides, HPLC of Formula: 4551-69-3, the publication is Dalton Transactions (2017), 46(34), 11259-11270, database is CAplus and MEDLINE.
The reactions of pyrrolidine derived salalen-type {ONNO} ligands (S)-L1-3-H2 with 1 equivalent M(OiPr)4(HOiPr) (M = Zr or Hf) in di-Et ether yielded complexes [L1-3M(OiPr)2] (L = L1, M = Zr (1); L = L2, M = Zr (2), Hf (3); L = L3, M = Zr (4), Hf (5)). All of these complexes were well characterized by NMR spectroscopy, elemental analyses and single-crystal x-ray anal. in the case of complexes 1 and 3–5. X-ray structural determination revealed that these complexes were analogous mononuclear species and had a similar structure in which the metal centers were six-coordinated to two oxygen atoms and two nitrogen atoms of one ligand and two oxygen atoms of two isopropoxy groups. All of these complexes efficiently initialized the ring-opening polymerization of lactides to afford polymers with controlled mol. weight and narrow polydispersity. Furthermore, the ring-opening polymerization of rac-lactide catalyzed by complexes 1–5 afforded isotactic-enriched polymers in solution (Pm = 0.74-0.80) and under melt conditions (Pm = 0.63-0.72).
Dalton Transactions published new progress about 4551-69-3. 4551-69-3 belongs to pyrazoles-derivatives, auxiliary class Benzenes, name is 4-Benzoyl-5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, and the molecular formula is C17H14N2O2, HPLC of Formula: 4551-69-3.
Referemce:
https://en.wikipedia.org/wiki/Pyrazole,
Pyrazoles – an overview | ScienceDirect Topics