Département de chimie moléculaire

{The isolation, structural characterization and electronic properties of a new mononuclear, pentacoordinate MnII complex [Mn(tButerpy)(N3)2] (1; tButerpy = 4,4',4''-tri-tert-butyl-2,2':6',2''-terpyridine) is reported. The X-ray structure of 1 reveals that the manganese ion lies in the center of a distorted trigonal bipyramid. The electronic properties of 1 were investigated by high-field and high-frequency EPR (HF-EPR) spectroscopy, allowing the detn. of the spin-Hamiltonian parameters. HF-EPR spectra were recorded on a neat powder of 1 and also on 1 magnetically dild. in the corresponding zinc complex. From the neat powder HF-EPR spectra, the following g and zero-field-splitting terms, as well as the sign of D, were obtained: D = -0.250(5) cm-1