Syntheses, crystal structures and magnetic properties of a new nitronyl nitroxide NIT2-bithph and its manganese(II) compound [Mn(hfac)2(IMHBithph)]2•(NIT2-bithph)(C6H14)

A new nitronyl nitroxide NIT2-bithph (1) and its manganese(II) compound [Mn(hfaC)(2)(IMHBithph)](2)-(NIT2-bithph)(C6H14) (2) (hfac=hexafluoroacetylacetonate; NIT2-bithph = 4,4,5,5-tetramethyl-2-(bithiophenal-2-yl)imidazoline-1-oxyl-3-oxide; IMHBithph = 1-hydroxy-2-bithiophenal-4,4,5,5-tetramethyl-4,5-dihydro- 1H-imidazole) have been synthesized and structurally characterized by X-ray diffraction methods. The units of compound I were connected as one-dimensional chain by the intermolecular hydrogen bonds which afford an intermolecular antiferromagnetic interaction between nitronyl nitroxide radicals within the chain (J = - 1.89 cm(-1)). Compound 2 resulting from the reaction of Mn(hfac)(2)center dot 2H(2)O and NIT2-bithph is dinuclear and includes the reduced amidino-oxide form of NIT2-bithph, it is made up of three parts: a [Mn(hfac)(2)(IMHBithph)](2) dimer unit, an uncoordinated NIT2-bithph radical and a noncoordinated solvent molecule of hexane, the molecule of radical is hydrogen bonded to its reduced form. Two reduced IMHBithph ligands bridge the two manganese(II) ions through their amidino-oxide oxygen atoms resulting in a small intramolecular antiferromagnetic interaction between the manganese ions(J= -1.55 cm(-1)). (C) 2006 Elsevier B.V. All rights reserved.