A self-assembled molecular ladder with Cu(H2O)4 units as cross rungs

The self-assembly of salicylaldehyde, d,l-aspartic acid and Cu(NO3)2 · 3H2O gave a 1D molecular ladder {[Cu2(sasp)2Cu(H2O)4] · 0.5H2O}n (1) in which Cu(H2O)4 units serve as cross rungs and two sasp–Cu–sasp–Cu chains with opposite chirality serve as side rails. Compound 1 displays strong antiferromagnetic interactions within Cu3O2 trinuclear units and weak interunit ferromagnetic interactions. Interchain hydrogen bonds result in weak antiferromagnetic interactions.