Supramolecular systems built from phenylcyanamido ligands. Syntheses, crystal structures and magnetic properties

Several new MnII compounds with X-phenylcyanamido (Xpcyd) and 2,2ʹ-bipyrimidine (2,2ʹ-bpm) bridging ligands of formula [Mn(pcyd) (MeOH)((mu)-pcyd)((mu)-2,2-bpm)0.5]n(1), [Mn(3-Clpcyd)(MeOH)((mu)-3-Clpcyd)((mu)-2,2ʹ-bpm)0.5]n(2), ((mu)-4-Clpcyd)2[Mn(4-Clpcyd) (H2O)(2,2ʹ-bpm)]2(3) and [Mn(3-Fpcyd)(MeOH)((mu)-3-Fpcyd)((mu)-2,2ʹ-bpm)0.5]n(4) have been synthesised and characterised. The one-dimensional compound [Mn(pcyd)(MeOH)((mu)-pcyd)((mu)-2,2ʹ-bpm)0.5]n(1) crystallises in the triclinic system, P space group and the dinuclear compound ((mu)-4-Clpcyd)2[Mn(4-Clpcyd)(H2O)(2,2ʹ-bpm)]2(3) crystallises in the orthorhombic system, P212121 space group. The two compounds contain the unusual end-to-end cyanamide bridge and give supramolecular 2-D networks by means of Hbonds. Susceptibility measurements on compounds 1-4 reveal moderate antiferromagnetic coupling in all cases. Coupling constants related to the phenylcyanamido bridges are compared with the superexchange model recently proposed for ligands of this kind.