Prasant Kumar Nanda

Tetranuclear Cu(II) complex supported by a central μ4-1,1,3,3 azide bridge

The new cluster [Cu4L2(N3)]Cl.16H2O has been synthesized and characterized; it features a unique mu4-1,1,3,3 bridging mode for azide, whose capacity to mediate magnetic coupling has been examined through bulk magnetic measurements and numeric fitting procedures.

Imidazolidine ring as a reduced heterocyclic spacer in a new all-N-donor μ-bis(bidentate) Schiff base ligand: Synthesis, characterization and electron transfer properties of imidazolidine-bridged dicopper complexes

Low-temperature stoichiometric Schiff base reaction in air in 3:1 mole ratio between benzaldehyde and triethylenetetramine (trien) in methanol yields a novel tetraaza μ-bis (bidentate) acyclic ligand L. It was characterized by elemental analysis, IR, EI mass and NMR (1H and13C) spectra. The formation of a five-membered imidazolidine ring from the ethylenediamine backbone as a spacer-cumbridging unit gives rise to a new type of imidazolidine-bridged ligand. A geometric optimisation was made of the synthesized ligand and its complexes by the method of molecular mechanics (MM2) method in order to establish the stable conformations. This hitherto unknown tetraaza acyclic ligand affords new cationic dicopper(I/I) and dicopper(II/II) complexes in good yield. Dicopper(II/II) complex displays weakd-d transition bands in the visible region, while dicopper(I/I) complex displays strong MLCT band in the same region. Both the dinuclear complexes are of non-intimate nature and show interesting solution electrochemical behaviour. EPR spectral study of μ-bis (imidazolidino) bridged dicopper(II/II) complex also supports the non-communicative nature of the two copper centres within the same molecule

An unusual square planar open-lock shaped copper(II) metallaligand obtained from a hexadentate amine-amide-phenol ligand

The copper(II) complex, [Cu(LH-2)] (4), asymmetrically coordinated by the tetradentate part of, 1,8-bis(2-hydroxybenzamido)-3,6-diazaoctane (L) is reported. Its structure involves a 1-D infinite chain that utilises hydrogen bonding between coordinated side amide carbonyl oxygen and uncoordinated metallaligand amide nitrogen atoms. Further complexation reaction of the metallaligand with [Cu(bpy)(MeOH)2](ClO4)2 gives [Cu2(LH-4)(bpy)] (5).