Synthesis and crystal structure of two novel PbII compounds of [Pb(endc)2(phen)]n and [Pb(endc)(phen) · 3H2O]2

Two novel PbII compounds [Pb(endc)2(phen)]n and [Pb(endc)(phen) · 3H2O]2 (endc and phen are the abbreviations of endonorbornene-cis-5,6-dicarboxylate anion and 1,10-phenanthroline, respectively) have been synthesized and characterized by single-crystal X-ray diffraction. [Pb(endc)2(phen)]n is a nine-coordinated catenulate-like polymer, and [Pb(endc)(phen) · 3H2O]2 is a hepta-coordinated dimer; both of them hold hemidirected coordination geometries. To the best of our knowledge, [Pb(endc)2(phen)]n is first hemidirected PbII coordinate with the coordination number of 9. For both compounds, the Pb–N, Pb–O(carboxyl) and Pb–O(carbonyl) bonds on the side away from lone pair of PbII are shorter than the rest of the same type, respectively; and these bonds become progressively longer, as they are arranged at the site nearer to the lone pair.