Syntheses and EPR spectral studies of manganese(II) complexes derived from pyridine-2-carbaldehyde based N(4)-substituted thiosemicarbazones: Crystal structure of one complex

摘要

Five manganese(II) complexes {[MnL21] center dot H2O center dot EtOH (1), [Mn(L-1)(HL1)]OAc (2), [MnL22] center dot 3H(2)O (3), [MnL23] center dot 3H(2)O (4) and [Mn(HL3)(2)](SCN)(2) center dot MeOH (5)} of three NNS donor N(4)-substituted thiosemicarbazone ligands (pyridine-2-carbaldehyde N(4)p-methoxyphenyl thiosemicarbazone [HL1], pyridine-2-carbaldehyde N(4)-2-phenethyl thiosemicarbazone [HL2] and pyridine-2-carbaldehyde N(4)-methyl, N(4)-phenyl thiosemicarbazone [HL3]) were synthesized and physico-chemically characterized. Compound 1 crystallized as [MnL21] center dot H2O and its structure has been determined by X-ray diffraction studies. It is found to have a distorted octahedral geometry. EPR spectra in DMF solutions at 77 K show hyperfine sextets with low intensity forbidden lines lying between each of the two main hyperfine lines. (C) 2007 Elsevier Ltd. All rights reserved.