Metal Complexes of π-Expanded Ligands (3): Synthesis and Characterization of tris[2-[(octylimino)methyl]-1-pyrenolato-N,O] cobalt(III)
Authors: Xuan Dien Luong , Kim Nga Nguyen , Thi Tuyet Mai Nguyen , Xuan Truong Nguyen , Yamashita Ken-ichi , Sugiura Ken-ichi Sugiura 
Published: June 2019

Abstract: The reactions of Co(OAc)2 with two equivalents of 1-hydroxy-2-[(octylimino)methyl-pyrene L, performed in air, lead to the formation of the cobalt(III) complex, tris[2-[(octylimino)methyl]-1-pyrenolato-N,O] cobalt(III) CoL3, accommodating three chelating pyrene-based salicylaldiminato-type ligands. The complex CoL3 and the referent tris(salicylaldiminato) cobalt(III) 1’(CoIII) were obtained in excellent yields, and their characterisation by 1H NMR, IR, mass spectroscopy, elemental analysis and X-ray diffraction revealed that they were of diamagnetic nature, octahedral geometry with the cobalt centre and meridional configuration. The redox behaviour of these complexes shows an irreversible reduction wave with a peak potential in the range -1.9 to -1.2 V. Upon reduction, the complexes decompose, giving rise to a redox pattern compatible with the formation of bis[2-[(octylimino)methyl]-1-pyrenolato-N,O] cobalt(II).

Keywords: Coordination chemistry, Cobalt, Pyrene, π-Expanded ligand, Salicylaldimine.

References:

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