Isotactic polypropylene (iPP) has been modified with various nucleating agents, based on layered metal monoglycerolate complexes. Increased crystallisation temperatures (T-c) of iPP were observed in the presence of the isostructural zinc and cobalt layered monoglycerolates (ZMG & CoMG) and the structurally-related calcium monoglycerolate (CaMG), at loadings as low as 200 ppm, indicating highly effective nucleation. Optical microscopic observations showed that iPP nucleates from the thin edges/sides of CoMG and not from the larger area flat hexagonal/rhombic surfaces of the platelets. X-ray powder diffraction (XRD) studies revealed predominantly selective alpha-nucleation, although small amounts of the beta-phase were observed with CaMG/iPP. The (040) peak of alpha-phase of iPP was enhanced for nucleated injection moulded samples. Molecular modelling indicated a close structural match between the edges of nucleating platelets and alpha-iPP in multiple lattice directions, each with a dimensional mismatch of less than 4%. (C) 2014 Elsevier Ltd. All rights reserved.