Synthesis, spectral, structure and computational studies of novel transition Metal(II) complexes of (Z)-((dimethylcarbamothioyl)thio) ((1,1,1-trifluoro-4-(naphthalen-2-yl)-4-oxobut-2-en-2-yl)oxy)

Abstract

Novel transition metal(II) complexes of (Z)-((dimethylcarbamothioyl)thio) ((1,1,1-trifluoro-4-(naphthalen-2-yl)-4-oxobut-2-en-2-yl)oxy) (M = Zn, Cu, Ni, Co, Fe and Mn) obtained from N,N′-dimethyldithiocarbamate (SDTC) and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (TFNB) have been synthesized and characterized by diverse analytical and spectroscopic techniques. The bonding nature, stereochemistry and chemical compositions of all the synthesized complexes were inferred from percentage metal, elemental analyses; infrared, electronic, mass spectra, conductivity, melting points, solubility and room temperature magnetic moments measurements. Cu(II) complex assumed a square-planar geometry, Mn(II), Fe(II) and Zn(II) complexes were tetrahedral while Co(II) and Ni(II) complexes are octahedral as deduced from electronic spectra and magnetic moments measurements. The infrared spectra data indicated that coordination with the metal ions in TFNB was via the carbonyl and enol oxygen atoms, while in SDTC the two sulphur atoms are involved. All the synthesized metal(II) complexes were covalent, as revealed by the conductivity measurements in dimethylformamide (DMF). The comparative TGA analysis of the metal complexes exhibit their thermal stability in the order: Zn(II) ˃ Co(II) ˃ Mn(II) ˃ Fe(II) ˃ Cu(II), while the computational studies of the complexes corroborate with the proposed structural geometries. Density functional theory (DFT) calculation showed that the complexes had low energy gap and higher tendency to interact with electron-accepting species.