Synthesis, Spectral Characterization of Mn(II) and Co(II) Complexes with Thiosemicarbazones and Semicarbazones Derived from Pyridine-2-Carboxaldehyde.

Mn(II) and Co(II) complexes are synthesized with L1(Pyridine-2-carboxaldehydethiosemicarbazones) and L2 (Pyridne-2-carboxaldehydesemicarbazones). These complexes were characterized by elemental analysis, molar conductance measurements, magnetic suscepectibility measurements, mass, IR, electronic and EPR spectral studies. The molar conductance measurement of the complexes in DMSO corresponds to non electrolytes nature with L1 and formulated as [M(L)2X2] where M=Mn(II) and Co(II) complexes. The molar conductance measurements with L2 lie in the range 208-217 Ω-1cm2mol-1 indicating the electrolytes nature of the complexes thus the complexes formulated as [M(L)2]X2 where M=Mn(II) and Co(II) complexes. On the basis of spectral studies an octahedral geometry has been assigned for Mn(II) and Co(II) complexes.

Synthesis, Spectral Characterization of Cu (Ii) and Ni (Ii) Complexes with Thiosemicarbazones and Semicarbazones Derived from Pyridine-2-Carboxaldehyde.

Ni (II) and Cu (II) complexes were synthesized with L1(Pyridine-2-carboxaldehydethiosemicarbazones) and L2 (Pyridine-2-carboxaldehydesemicarbazones). These complexes were characterized by elemental analysis, molar conductance measurements, magnetic susceptibility measurements, mass, IR, electronic and EPR spectral studies. The molar conductance measurements on the complexes in DMSO correspond to non electrolytes nature with L1. The molar conductance measurements with L2 lie in the range 210-226 Ω-1cm2mol-1 indicating the complexes were 1:2 electrolyte thus the complexes may be formulated as [M(L)2]X2 where M= Ni (II) and Cu (II) complexes. On the basis of spectral studies an octahedral geometry has been assigned for Ni (II) complexes. A tetragonal geometry suggested for Cu (II) complexes.

Spectroscopic and biological studies on newly synthesized copper (II) and nickel (II) complexes with p-Dimethylaminobanzaldehyde semicarbazone and p-Dimethylaminobanzaldehyde thiosemicarbazone.

Cu (II) and Ni (II) complexes of general composition [ML2]X2 (M = Cu(II), Ni(II); X = Cl-, NO3 -) were synthesized by the condensation of metal salts with semicarbazone / thiosemicarbazone derived from pdimethylaminobanzaldehyde. The metal complexes were characterized by elemental analysis, molar conductance, magnetic susceptibility measurements, IR and atomic absorption spectral studies. On the basis of electronic and infrared spectral studies, the metal complexes were found to have tetrahedral geometry. The Schiff bases and their metal complexes were tested for their antibacterial and antioxidant activities.

Green approach for the synthesis of silver-nanoparticles and efficient use in oxidative cyclization.

Highly concentrated and stable suspension of Ag-nanoparticles were synthesized by the chemical reduction of AgNO3 in a reductant using a macrocyclic Schiff base ligand benzildiethylenetriamine and low molecular weight organic compound, thiosalicylic acid(TSA) used as a protective agent. The average size of the silver nanoparticles prepared from this method was less than 20 nm, which allowed low-temperature sintering of the metal. Ag-nanoparticles provide an efficient catalysis for the synthesis of heterocyclic compounds by coupling salicyldehyde with aliphatic amines through the oxidative cyclization of Schiff base using 10 mol. % of Ag-nanoparticles in the presence of Na2CO3 in MeOH. This method avoids the usage of metal oxides or organic oxidizing agents.