THE INFRARED SPECTRA (4000 - 50 cm⁻¹) OF COMPLEXES OF QUINOLINE N-OXIDE AND ITS PERDEUTERATED ANALOGUE WITH METAL(II) PERCHLORATES OF THE FIRST TRANSITION SERIES

Abstract

Infrared assignments (4000 - 50 cm⁻¹) are presented for the complexes [M(quinO)_n](ClO₄)₂(quinO = quinoline N-oxide; n = 6 for Mn, Co, Ni; n = 5 for Zn, and n = 4 for Cu) and their perdeuterated analogues. The spectra are consistent with octahedral structures for the 6-coordinate complexes, a trigonal bipyramidal structure for the Zn(II) complex and a square planar structure for the Cu(II) complex, with some distortion from idealised symmetry evident for each complex. In the Mn(II) complex, strong coupling occurs between the vM-O of lowest frequency and the ligand vibration, xN-O (mode 45). In the Cu(II) complex, the single vCu-O is strongly coupled with the ring torsion (mode 28).

Key Words:

• quinoline N-oxide
• infrared spectra
• complexes
• isotopic labelling