The crystal structures of two compounds have been determined, namely [Ce(NO3)3{Cu(salen)}2] (1) and [Gd(NO3)3Cu(salen)] (2), salen being N,N′-ethylenebis(salicylideneaminato). The compounds [Ln(NO3)3Cu(salen)] with Ln=Tb (3), Dy (4), Ho (5) and Er (6), which are ...