Mn(III) complexes with asymmetrical N2O3 Schiff bases. The unusual crystal structure of [Mn(phenglydisal-3-Br,5-Cl)(dmso)] (H3phenglydisal = 3-aza-N-{2-[1-aza-2-(2-hydroxyphenyl)vinyl]phenyl}-4-(2-hydroxyphenyl)but-3-enamide), a mononuclear single-stranded helical manganese(III) complex

Abstract

Neutral manganese(III) complexes, with potentially pentadentate and trianionic asymmetrical Schiff bases, containing a hard amido donor atom, have been synthesised. Complexes are found to be of the form MnIII(phenglydisal-R)(H2O)n (n = 1–4) [H3phenglydisal = 3-aza-N-{2-[1-aza-2-(2-hydroxyphenyl)vinyl]phenyl}-4-(2-hydroxyphenyl)but-3-enamide; R = H; 3-OEt, 4,6-(OMe)2, 5-NO2, 3-OMe, 5-Br, 3-Br,5-Cl] and have been characterised by elemental analyses, FAB mass spectrometry, IR and 1H NMR spectroscopies, magnetic measurements, molar conductivities and cyclic voltammetry. [Mn(phenglydisal-3-Br,5-Cl)(dmso)] 3, was also crystallographically characterised and its crystal structure shows the manganese atom in an octahedral environment, with the ligand giving rise to a mononuclear single-stranded helical complex.