Theoretical and Experimental EPR Study of VO2+-Doped Ammonium Hydrogen Tartrate

We studied the electron paramagnetic resonance (EPR) spectra of VO2+ ions in ammonium hydrogen tartrate (AHT) single crystals at room temperature. We determined the spin Hamiltonian parameters and the molecular bonding coefficients of the complex both in theoretical and experimental ways. The results indicate that the vanadium ion forms a tetragonally compressed octahedron and has a double bond with one of the oxygens in the axial position. This is the reason why the paramagnetic centre in the host crystal is axially symmetric as in most of the vanadyl ion-containing complexes.

New Insights into the Chemistry of Oxovanadium(IV) Complexes with N4 Coordinating Ligands

The syntheses of new oxovanadium(IV) complexes having general formula [VO(mac)]SO4 have been carried out by using in situ method of preparation where vanadyl ion acts as kinetic template for the ligands derived by condensation of 2,2′-pyridil with 1,2-diaminopropane and 1,3-diaminopropane. The complexes were characterized by elemental analyses, molar conductance, magnetic moments, and spectral (infrared, electronic, and electron spin resonance) data. All the oxovanadium(IV) complexes are five coordinate wherein derived ligands act as tetradentate chelating agents.

Synthesis of Oxovanadium(IV) Complexes with Tetraaza Coordinating Ligands

Oxovanadium(IV) complexes of the type [VO(mac)]SO4(where mac = tetraaza macrocyclic ligands derived by condensation of thenil with 1,4-diaminobenzene or 3,4-diaminopyridine and their reaction withβ-diketones) have been prepared using vanadyl ion as kinetic template. The prepared macrocyclic complexes were characterized by elemental analyses, molar conductance, magnetic moments, and infrared, electronic, and electron spin resonance data. From the spectroscopic studies, five-coordinate square-pyramidal geometry for the VO2+complexes have been proposed wherein derived ligands act as tetradentate chelating agents.