The photomagnetic effect in 2-D cyanido-bridged coordination polymer [Cu(aepa)]10[Mo(CN)8]5·30H2O

Self assembly of Cu2+ and [Mo(CN)8]4− ions in the presence of a tridentate polyamine aepa ligand (aepa = N-(2-aminoethyl)-1,3-propanediamine) allowed the formation of 2-D cyanido-bridged molecular system [Cu(aepa)]10[Mo(CN)8]5·30H2O (1). The structure of the polymeric assembly reveals a complicated topology exhibiting 4-, 6-, 8- and 16-metallic rings. The magnetic properties of 1 are typical for a paramagnetic system consisting of Cu(II) centres with g = 2.15. Irradiation of 1 with 450 nm light caused an increase of the magnetisation suggesting singlet–triplet transition on the Mo(IV) centre from the S = 0 ground state to the S = 1 excited state. The photoinduced state has been characterised using DC magnetic techniques and showed relaxation upon heating up to 300 K.