FT-IR, ESI and EPR studies of a Dy(III) Schiff base podand complex

IR spectroscopic, electrospray ionization mass spectrometry, structure and magnetic properties of a dysprosium(III) macroacyclic tripodal Schiff base tris((2-(5-chlorosalicylideno)amino)ethyl)amine (tren-5Clsal) complex are reported. The positions of ν(CN) stretching bonds indicate that the azomethine group nitrogen is coordinated to the rare earth ion. Two main spectral components are observed in the low magnetic field region (<300 mT) in the EPR spectra, independently of temperature. These components are attributed to the Dy3+ ion with an effective spin of S = 1/2. The magnetic anisotropy between 3 and 23 K is practically constant as evidenced only by a marginal change of the spread of g-factors. The gy-factor increases strongly with an increase in temperature above 23 K, giving rise to a very high magnetic anisotropy of the complex. Such behavior of the magnetic anisotropy at a higher temperature could be an effect of the existence of an excited doublet. A very small value of the Curie–Weiss constant and the lack of any meaningful thermal changes of linewidths indicates the absence of any significant interactions between Dy(III) complexes below 20 K. The temperature dependence of the total integrated intensity above 20 K indicates the existence of an excited doublet, occurring about 33(1) K above the ground state.