Synthesis and Structural Characterisation of Palladium(II) Complexes with N,N′,N-Tridentate N′-Substituted N,N-Di(2-picolyl)amines and their Application to Methyl Methacrylate Polymerisation

Abstract

The reaction of [Pd(CH3CN)2Cl2] with N′-substituted N,N-di(2-picolyl)amine-based ancillary ligands, for example N,N-di(2-picolyl)cyclohexylmethylamine (L1), N,N-di(2-picolyl)benzylamine (L2), N,N-di(2-picolyl)aniline (L3), and 1,4-bis[bis(2-pyridylmethyl)aminomethyl]benzene (L4), in the presence of NaClO4 in ethanol yields a new series of [(NN′N)PdCl]X (X = ClO4, Cl) complexes, i.e. mononuclear [LnPdCl]ClO4 (Ln = L1, L2, L3) and binuclear [L4Pd2Cl2]Cl2. X-Ray crystallographic analysis determined that the Pd atom in complexes [(NN′N)PdCl]X showed a slightly distorted square-planar geometry involving three nitrogen atoms and a chlorido ligand. Moreover, the unit cell included a ClO4– or Cl– anion as the counterion. The complex [L1PdCl]ClO4 showed the highest catalytic activity for the polymerisation of methyl methacrylate in the presence of modified methylaluminoxane at 60°C among the mononuclear PdII complexes. Specifically, the activity of binuclear [L4Pd2Cl2]Cl2 was 2-fold higher than the corresponding mononuclear [L2PdCl]ClO4 per active palladium metal centre.

Zinc (II), palladium (II) and cadmium (II) complexes containing 4‐methoxy‐N‐(pyridin‐2‐ylmethylene) aniline derivatives: Synthesis, characterization and methyl methacrylate polymerization

“…Recently, we have studied Zn (II), Cd (II), Co (II), Pt (II) and Pd (II) complexes with N , N ‐di(2‐picolyl) amine, 2‐iminomethylpyridine, N ‐methyl‐ N ‐((pyridin‐2‐yl)methyl) cyclohexanamine, N ‐(pyridin‐2‐ylmethyl) aniline and N , N ‐di(2‐picolyl) cycloalkylamine ligands in MMA polymerization with promising results, as a slight difference in ligand architecture is able to influence the stereoregular outcomes during polymerization reactions. Thus, suitable ligand architecture around the metal center is vital for achieving a high degree of polymerization as these complexes/initiators regulate various steps involved in polymerization .…”

Chitosan Functionalized with 2-Methylpyridine Cross-Linker Cellulose to Adsorb Pb(II) from Water

“…Other research groups have reported that chitosan is widely modified to improve its adsorption capacity. One of these modifications involves the incorporation of pyridine derivatives [ 31 , 32 , 33 , 34 ]. In this context, the present study shows the results of the synthesis of cellulose cross-linking with a chitosan-pyrimidine derivative using a fast and accessible methodology.…”