COORDINATION POLYMERS .9. SYNTHESIS AND CRYSTAL-STRUCTURE OF A 1D-SODIUM COORDINATION POLYMER - [NAL(4)(PMDETA)]INFINITY

Reaction of sodium hydride with the tridentate tetrazole ligand 10 (HL(4)) and pentamethyldiethylenetriamine (PMDETA) in toluene yields by self-assembly in the solid-state the well-ordered 1D-coordination polymer [NaL(4)(PMDETA)](infinity) (11). The structure of 11 was established by single-crystal X-ray diffraction. The generation of the 1D-polymer 11 is understandable if intermediate formation of coordinatively unsaturated, neutral sodium building blocks [NaL(4)(PMDETA)] (12) is assumed. Such a self-complementary monomer 12 acts in a monodentate fashion via its CN group, leading to linkage of monomers and to coordinative saturation at the sodium centre of 12. The sodium ions of the resulting polymeric chains of 11 are coordinated in a distorted octahedral manner. These results indicate that sodium derivatives of CN-containing ligands may be tuned as to their dimensionality, especially so since Na+ can cope with coordination numbers of 4, 5, or 6; such tuning could be probed initially by provision of further available functionalities within the anionic ligand and/or by provision of Lewis base donors of varying denticity.