• Bikash Kumar Panda

      Articles written in Journal of Chemical Sciences

    • Synthesis, characterization and emission properties of quinolin-8-olato chelated ruthenium organometallics

      Bikash Kumar Panda

      More Details Abstract Fulltext PDF

      The reaction of Ru(RL1)(PPh3)2(CO)Cl,1, with quinolin-8-ol (HQ) has afforded complexes of the type [Ru(RL2)(PPh3)2(CO)(Q)],3, in excellent yield (RL1 is C6H2O-2-CHNHC6H4R(p)-3-Me-5, RL2 is C6H2OH-2-CHNC6H4R(p)-3-Me-5 and R is Me, OMe, Cl). In this process, quinolin-8-olato (Q) undergoes five-membered chelation, the iminium-phenolato function tautomerizing to the imine-phenol function. In dichloromethane solution,3 displays a quasireversible3+/3 couple near 0·50 V vs SCE (3+ is the ruthenium (III) analogue of3). Coulometrically generated solutions of3+ display a strong absorption near 395 nm associated with a shoulder near 475 nm and rhombic EPR spectra withg values near 2·55, 2·13, 1·89. Solutions of3 absorb near 415 nm and emit near 510 nm at 298 K and 585 nm at 77 K. The fluorescence is believed to originate from the3MLCT state

    • Oximato bridged Rh$^{\text{III}}_2$MII and RhIIIMI species (MII = Mn, Co, Ni; MI = Cu, Ag)

      Indranil Bhattacharyya Sanjib Ganguly Bikash Kumar Panda Animesh Chakravorty

      More Details Abstract Fulltext PDF

      The reaction of [RhCl2(HPhL)(PhL)] with MII(ClO4)2.6H2O in presence of alkali has furnished trinuclear [RhCl2(PhL)2]2M(H2O)$_2.$H2O (HPhL is phenylazobenzaldoxime; M = Mn, Co, Ni). A similar reaction with MI(PPh3)2NO3 yielded binuclear [RhCl2(PhL)2]M(PPh3)2 (M = Cu, Ag). In these molecules the oximato group acts as a bridge between RhIII (bonded at N) and MII or MI (bonded at O). In structurally characterized [RhIIICl2(PhL)2]2Mn(H2O)2.H2O the centrosymmetric distorted octahedral MnO6 coordination sphere is spanned by four oximato oxygen atoms and two water molecules lying in trans position. In the lattice the neighbouring molecules are held together by H2O$\cdots$H2O$\cdots$H2O hydrogen bonds generating infinite zigzag chains. The manganese atoms lie parallel to the C-axis, the shortest Mn…Mn distance being 7.992 Å. Magnetic exchange interactions if any are small as seen in room temperature magnetic moments. The manganese system displays a strong EPR signal near 𝑔 = 2.00. In the complex [RhCl2(PhL)2]Cu(PPh3)2 the copper atom is coordinated to two oximato oxygen atoms and the two phosphorus atoms in a distorted tetrahedral geometry. The softness of the phosphine ligand is believed to sustain the stable coordination of hard oximato oxygen to soft CuI. The coordination sphere of the RhIII atom in both the complexes is uniformly trans-RhN4Cl2.

  • Journal of Chemical Sciences | News

© 2017-2019 Indian Academy of Sciences, Bengaluru.