Synthesis and Characterization of Cobalt(II) Complexes with Two Twelve‐Membered Tetraaza Macrocyclic Ligands

Abstract

Cobalt(II) complexes of the general composition CoLX₂ {where X = Cl, ½SO₄, NO₃, and SCN; L = 2,3,8,9‐tetramethyl‐1,4,7,10‐tetraazacyclododeca‐1,3,7,9‐tetraene [N₄] (DAED) or 2,3,8,9‐tetraphenyl‐5,11‐dimethyl‐1,4,7,10‐tetraazacyclododeca‐1,3,7,9‐tetraene[N₄] (BDAP)} have been prepared. On the basis of electronic and EPR spectral studies, the chloro, nitrato and thiocyanato complexes were found to have six‐coordinate, octahedral geometry and the sulfato complexes were found to have five‐coordinate, trigonal‐bipyramidal geometry.

Keywords:

• Cobalt(II) complexes
• DAED
• BDAP
• Synthesis
• Characterization

Acknowledgments

The authors are thankful to the Ministry of Science & Technology, New Mehrauli Road, New Delhi, for financial assistance and the Regional Sophisticated Instrumentation Centre, Indian Institute of Technology, Bombay, for recording the ESR spectra of the complexes.