New magnetic behaviour of honeycomb layered compounds. Crystal structures of ?M2(bipym)(N3)2? (M = CoII, FEII; bipym = 2,2'bipyrimidine

A one-pot reaction of Co(N0&.6H20 or FeC12, 2,2'- bipyrimidine (bipym) and NaN3 affords the two [M2- (bi~yrn)(N~()M~] = CoII 1, FeI1 2) honeycomb sheetlike compounds with alternating double end-on azide and bis(che1ating) bipym bridging groups; magnetic susceptibility measurements indicate that they exhibit ferromagnetic (through the end-on azide) and antiferromagnetic (through bipym) magnetic interactions, their magnetization studies revealing the occurrence of metamagnetic like behaviour