Coordination Chemistry of Pyridylmetylamino-Substituted Cyclo- and Polyphosphazenes: Selectivity in Macromolecule Complex Formation and a Ligand-Stabilised [Cu₁₃O₉]-Cluster

Abstract

Polyphosphazenes with 2-, 3-, and 4-pyridylmethylamino- and phenoxy groups show a rather surprising ion uptake behaviour in reactions with diluted solutions of copper(II)- and cobalt(II)- or nickel(II) salts. Capacity and selectivity for copper of the 2-pyridyl-methylamino-substituted polymers are higher than of the other derivatives and are increasing with an increasing number of the functional groups present on the chain. By contrast, polyphosphazenes with more than 50% of 3-pyridylmethylamino substitution and polyphosphazenes with 4-pyridylmethylamino groups show decreasing metal sorption with increasing numbers of functional groups. A [Cu₁₃O₉]-cluster, stabilised by a ligand shell, is formed in the reaction of trans-vic-N₃P₃(OC₆H₅)₄(NHCH₂C₅H₄N-2)₂ with copper(I) iodide and oxygen. The anion is a new iodo cuprate, [Cu₆I₉]³. The molecular structure of the compound was determined by single crystal X-ray structure analysis.

KEY WORDS::

• Phosphazenes
• Copper Cluster
• Iodo Cuprate
• Ion Uptake