Synthesis and characterization of TCNQ derivatives of Ni(II) and Cu(II) with pyrazole-based ligands

Abstract

Reactions between nickel(II) and copper(II) salts [M(L) n ](ClO4)2 [L: 2-(pyrazole-1-ylmethyl)pyridine; n = 3 for Ni(II) and n = 2 for Ni(II) and Cu(II)] and LiTCNQ or mixture of LiTCNQ/TCNQ and Et3NH(TCNQ)2 yielded [Ni(L)3](TCNQ)2 · H2O, [Ni(L)2(TCNQ)2], [Ni(L)3](TCNQ)3, [Ni(L)2(TCNQ)3], and [Cu(L)2(TCNQ)3] · 3H2O. These complexes were characterized by infrared, electronic absorption, variable temperature magnetic moments and electron paramagnetic studies. Magnetic moments increase with increase in temperature attributed to contribution from TCNQ, which has also been examined by electron paramagnetic resonance.