Synthesis and Characterization of Spin-Free [Co2(N,N′-Tetra(4-antipyrylmethyl)-1,2-diaminoethane)Cl4]

Abstract

The ligand N,N H -tetra(4-antipyrylmethyl)-1,2-diaminoethane (TAMEN) coordinates to two Co(II) ions and forms the tetrahedral homodinuclear complex [Co 2 (TAMEN)Cl 4 ]. In methanol, the complex shows a weak absorbtion spectrum with a maximum at 515 AE 0.5 nm and a molar absorbtivity of 40.0 AE 1.0 lÁmol À1 Ácm À1 . Variable temperature spectra (282 to 323 K) show no changes of this band and suggest the absence of thermochromicity. The magnetic moments amount to 4.93 to 5.00 " B at the temperature range of 232 to 329 K, demonstrating the complex to be spinfree in methanol.

Broad-Range Spectral Analysis for Chiral Metal Coordination Compounds: (Chiro)optical Superspectrum of Cobalt(II) Complexes

“…The observed magnetic moments values (μ eff = 4.0–4.2 μ B for both compounds) correspond to the existence of a tetrahedral high-spin cobalt­(II) complex. − The spin magnetic moment for three unpaired electrons is 3.88 μ B ; the residual difference (0.1–0.3 μ B ) with respect to the measured value of μ eff is due to the contribution of the orbital angular magnetic moment…”