Département de chimie moléculaire

{The isolation and structural characterization of [(terpy)MnIII(N3)3] (1) is reported (terpy = 2,2':6',2''-terpyridine). Complex 1, a product of the reaction between the mixed-valence dimer [(terpy)(H2O)MnIII(O)2MnIV(OH2)(terpy)](NO3)3 and NaN3, crystallizes in a triclinic system, space group P1̅, a 8.480(1), b 8.9007(2), c 12.109(2) {\AA}, $\alpha$ 93.79(1), $\beta$ 103.17(1), $\gamma$ 103.11(1)°, and Z = 2. Complex 1 exhibits a Jahn-Teller distortion of the octahedron characteristic of a six-coordinated high-spin Mn(III). A vibrational spectroscopic study was performed. The $ν$asym(N3) mode of complex 1 appears in the IR as a strong band at 2035 cm-1 with a less intense feature at 2072 cm-1, and in the FT-Raman as a strong band at 2071 cm-1 with a weaker broad band at 2046 cm-1. The electronic properties of complex 1 were studied using a high-field and high-frequency EPR study (190-475 GHz). The different spin Hamiltonian parameters were detd. (D = -3.29 (±0.01) cm-1