3814-80-0Relevant articles and documents
Thiosemicarbazones as Co-ordinating Agents. Solution Chemistry and X-Ray Structure of Pyridoxal Thiosemicarbazone Trihydrate and Spectroscopic Properties of its Metal Complexes
Belicchi, M. Ferrari,Gasparri, G. Fava,Leporati, E.,Pelizzi, C.,Tarasconi, P.,Tosi, G.
, p. 2455 - 2462 (2007/10/02)
The ligand behaviour of pyridoxal thiosemicarbazone (H2L) was examined in a series of metal complexes of formula M(H2L)X2, M(HL)X, and ML (M = Co, Ni, Cu, or Zn; X = NO3 or CH3CO2) which are characterized by analytical methods and i.r. spectroscopy.Changes in the vibrational absorptions of the ligand upon co-ordination are discussed, The X-ray structure of uncomplexed H2L*3H2O was determined.Crystals are monoclinic, space group P21/n, with a=16.126(1), b=7.267(1), c=12.466(1) Angstroem, and β=108.60(1)o.The structure was solved by direct methods and refined by full-matrix least squares to a final R value of 0.058 for 1262 observed reflections.The thiosemicarbazone moiety shows an E configuration about both the C(2)-N(3) and C(1)-N(2) bonds, and the phenolic oxygen is trans to N(3).The protonation constants of H2L were determined by spectrophotometric methods at 25 deg C and I = 0.5 mol dm-3 (KCl): log β011 = 11.111(22), log β021 = 19.048(25), and log β031 = 23.342(27).The spectrophotometric characteristics of various species are reported; the experimental spectra are in good agreement with calculated ones.
