Synthesis, structural characterisation, and Monte Carlo simulation of the magnetic properties of the 3D-stacked honeycomb Cs-n[{Mn(N-3)(3)}(n)] and the irregular double chain [{N(C2N5)(4)}(n)][{Mn-2(N-3)(5)(H2O)}(n)]

Two new polymeric manganese-azido systems with formula Cs-n-[(Mn(N-3)(3))(n )] (1) and [(N(C2H5)(4))(n)][(Mn-2-(N-3)(5)(H2O))(n)] (2) were synthesised and structurally characterised. Compound 1 crystallises in the P2(1)/n grou p and consists of a three-dimensional system with end-to-end and end-on azi do bridges with the caesium atoms in the holes of the net. Magnetically, co mpound I is a rare case of a three-dimensional network with alternate ferro -antiferromagnetic interactions. Compound 2 crystallises in the P (1) over bar group and consists of double chains of manganese atoms bridged by end-o n and, the exceptional, (mu-1,1,1)-azido bridges. Magnetically, compound 2 shows net ferromagnetic behaviour. Exact fit of the magnetic data was perfo rmed for the two compounds by means of Monte Carica simulations based on th e Metropolis algorithm on sets of 10 x 10 x 10 (1) and 1 x 1 x 320 (2) S = 5/2 classical spin centres.