A lead (II) 3D coordination polymer based on a marine cyclic peptide motif

The crystal structure of a naturally occurring cyclic tetrapeptide cyclo(Gly-LSer-L-Pro-L-Glu) [cyclo(GSPE)] was obtained. The conformation of synthesized cyclo(GSPE) fixes the coordination to lead ion in a 1:1 ratio. This cyclo(GSPE)-Pb complex was constructed as an asymmetric 3D network in the crystalline state. The polymerization of a heavy metal ion with a rigid asymmetric cyclic tetrapeptide represents the first example of a new class of macrocyclic complexes. © 1996-2013 MDPI AG (Basel, Switzerland).