Zn(II) and Cd(II)-azido/thiocyanato complexes with thiazolylazo dye and triphenylphosphine: synthesis, characterization and fluorescence

Abstract

[M(L)(PPh3)2X2] [where M = Zn(II) or Cd(II); L = 4-(4′-phenyl, 2′-thiazolylazo)chlorobenzene (L1 ), 4-(4′-phenyl, 2′-thiazolylazo)bromobenzene (L2 ), 4-(4′-phenyl, 2′-thiazolylazo)iodobenzene (L3 ); PPh3 = triphenylphosphine; X = or NCS−] have been prepared. The complexes were characterized by microanalyses, molar conductance, IR, UV–vis, 1H NMR, 31P NMR, and mass spectral studies. IR spectra reveal that L1–3 coordinate bidentate via azo and thiazole nitrogens. An octahedral geometry is proposed for all the complexes. Thermal behavior indicates that the thiocyanate complexes are more stable than the azide complexes. All the complexes exhibit blue-green emission as a result of fluorescence from the intraligand (π → π ∗) emission excited state.