6533b823fe1ef96bd127e965

RESEARCH PRODUCT

A novel dinuclear manganese(II) compound incorporating two bis(imidazolyl) based ligands with single μ2-η1:η1-carboxylato bridges. Molecular and crystal structure and magnetic properties of [Mn2Cl(BIP)(HBIMAM)(H2O)5]Cl3·4H2O (BIP=3,3-di(2-1H-2-imidazolyl)propanoate; BIMAM=N-methyldi(1H-2-imidazolyl)methanamine)

subject

description

Abstract This paper reports the synthesis, X-ray structure and magnetic characterization of [Mn 2 Cl(BIP) (HBIMAM)(H 2 O) 5 ]Cl 3 ·4H 2 O a novel dinuclear manganese(II) incorporating two related bis(imidazolyl)-based ligands, BIP (3,3-di(2-1 H -2-imidazolyl)propanoate) and BIMAM ( N -methyldi(1 H -2-imidazolyl)methanamine). The metal atoms in the dinuclear entity are bridged by a μ 2 -η 1 :η 1 carboxylate group (from the propionate arm of the BIP ligand) acting in an anti – anti coordination bridging mode, with an intramolecular Mn⋯Mn distance of 6.47 A. The coordination around the Mn(II) ions shows a distorted octahedral geometry for both MnClN 2 O 3 and MnN 2 O 4 chromophores. Between the imidazole rings of neighbouring dinuclear units there significant aromatic–aromatic interactions. The propagation of these interactions generates chains of π-stacked dinuclear units, roughly running along the [1 0 0] direction. Magnetic susceptibility measurements in the range 2–300 K show weak antiferromagnetic exchange interactions which were analysed by means of the isotropic S 1  = S 2  = 5/2 spin-coupled dimer model H ˆ = - 2 J ( S ˆ 1 · S ˆ 2 ) . Finally, the observed magnetic behavior (2 J  = −0.38(1) cm −1 ) is compared with that observed in related manganese(II) compounds with single [Mn(μ 2 -η 1 :η 1 -carboxylato)Mn] core.