The preparations and characterisations of a range of lanthanoid 4-(R)-substituted (4-Rcinn, R ϭ OH, OMe, NO 2 , Cl), known to have good anticorrosion properties, are reported. The crystal structure of [Ce(4-OHcinn) 3 (MeOH) 2 (H 2 O)] · MeOH is a polymer, in which the cerium atoms are nonacoordinate, and 833 adjacent cerium atoms are bridged by either two bridging bidentate or two bridging tridentate carboxylate ligands. Each cerium atom also has one monodentate 4-hydroxycinnamate ligand, one aqua ligand, and two methanol ligands.