Comparative investigation of the copper(II) complexes of (R)-, (S)- and (R,S)-1-phenyl-N,N-bis(pyridine-3-ylmethyl)ethanamine along with the related complex of (R,S)-1-cyclohexyl-N,N-bis(pyridine-3-ylmethyl)ethanamine. Synthetic, magnetic, and structural studies

Crystal structure of {(S)-1-phenyl-N,N-bis-[(pyridin-2-yl)meth-yl]ethanamine-κ3N,N',N''}bis-(thio-cyanato-κN)zinc from synchrotron data

The title ZnII complex, [Zn(NCS)2(C20H21N3)], has been characterized by synchrotron single-crystal diffraction and FT-IR spectroscopy. The central ZnII ion has a distorted square-pyramidal coordination geometry, with three N atoms of the chiral (S) 1-phenyl-N,N-bis-[(pyridin-2-yl)meth-yl]ethanamine (S-ppme) ligand and one N atom of a thio-cyanate anion in the equatorial plane, and one N atom of another thio-cyanate anion at the apical position. The average Zn-N S-ppme and Zn-NNCS bond lengths are 2.183 (2) and 1.986 (2) Å, respectively. In the crystal, inter-molecular C-H⋯S hydrogen bonds and a face-to-face π-π inter-action [centroid-centroid distance = 3.482 (1) Å] link the mol-ecules and give rise to a supra-molecular sheet structure parallel to the ac plane.

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

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.