CHARACTERIZATION OF SOME SCHIFF BASES OF HETEROCYCLIC COMPOUNDS AND THEIR TRANSITION METAL COMPLEXES

Some new Schiff bases were synthesized by the condensation of equimolar quantities of salicylaldehyde and 2-amino-5-phenylazo-pyridine or its derivatives in dry benzene(1):Metal complexes of the type ML_2and M'L_3 where M=Cu^(2+),Co^(2+),Ni^(2+),Mn^(2+)Pd^(2+),M'=Fe^(3+)and L=different newly synthesized monobasic Schiff bases were prepared in absolute ethanolic medium(2)and characterized by elementary analysis,conductance measurements,infrared spectra,electronic spectra,magnetic moments studies.

Polymerization of isoprene catalyzed by neodymium heterocyclic Schiff base complex

Neodymium-based heterocyclic Schiff base complex was prepared and applied for the coordination polymerization of isoprene. This complex polymerized isoprene to afford products featuring high cis-1,4 stereospecificity （ca. 95%） and high molecular weight （ca, 10^5） in the presence of the triisobutyl aluminium （AliBu3） as cocatalyst, The microstructure of obtained polyisoprene was investigated by FTIR, 1^H NMR. Two different kinds of active centers in the catalyst system were examined by GPC method.

HETEROCYCLIC SCHIFF BASE NEODYMIUM COMPLEX AS CATALYST FOR RING-OPENING POLYMERIZATION OF ε-CAPROLACTONE

An aromatic heterocyclic Schiff base neodymium complex bearing thiazole was synthesized and its activity in the ring-opening polymerization ofε-caprolactone(CL)was examined.The conditions of the CL/Nd molar ratio,monomer concentration,polymerization time and temperature were investigated.Activities of ca.171 kg/Nd·h were obtained under the optimum condition(CL/Nd=1600(molar ratio),[CL]=2.26 mol L^(-1),1 h at 50℃),giving a poly(ε-caprolactone)(PCL)of number-average molecular weight M_n=5.4×10~4 and molecular...

Synthesis and Crystal Structure of Bis(N’-(Pyridine-3-Carboxaldehyde) Isonicotinoylhydrazone) Zinc(II)

Zinc complexes of Schiff base ligands exhibit interesting properties which could be exploited for potential applications as catalysts and models for biochemical systems. In this study, we report of the synthesis of a new zinc Schiff base complex, bis(N’-(pyridine-3-carboxaldehyde) isonicotinoylhydrazone) zinc(II), which has been characterized by physico-chemical methods. The X-ray single crystal structure of the complex has also been determined. The Schiff base ligand is bonded to the metal in a monodentate manner, coordinating through the pyridine N-atom, as shown from spectral studies. The crystal structure shows the zinc atom bonded to two Schiff bases and four aqua ligands, with each Schiff base ligand coordinating through its pyridine N-atom forming a distorted octahedral ZnN2O4 complex. Two water molecules and two nitrate ions found in the crystal structure link the different monomers through hydrogen bonding to form a layered supramolecular structure.

Synthesis of ribonucleoside analogues containing thio-substituted 1,3,4-triazole as heterocyclic base

New ribonucleoside analogues containing thio-substituted 1,3,4-triazole as heterocyclic base have been synthesized via condensation of the central intermediate 1 with various acids, esters, amides, and anhydrides in anhydrous solvent followed by deprotection.