The objective of this US-Poland research project between Dr. Alan L. Balch of the University of California-Davis and Dr. Lechoslaw Latos-Grazynski of the Institute of Chemistry, University of Wroclaw, Poland, is to explore the synthesis and coordination properties of core-modified porphyrins -- porphyrins which one or more of the pyrrole nitrogens has been altered, particularly by replacement with a different heteroatom. The researchers anticipate that these ligands will stabilize metal ions in low oxidation states and in planar, rather than tetrahedral geometry. The reactivity of the metal ions in these unusual environments will be examined. They will continue their studies of the coordination properties of monothiaporphyrins, particularly their (formal) Ni(I) and Pd(I) complexes. Results are expected to improve our understanding of certain aspects of metallobiochemistry and may yield complexes that are good catalysts for alkylation or oxidation of organic molecules. This project in chemistry fulfills the program objective of advancing scientific knowledge by enabling leading experts in the United States and Eastern Europe to combine complementary talents and pool resources in areas of strong mutual interest and competence.