Engineering Coordination and Supramolecular Copper−Organic Networks by Aqueous Medium Self-Assembly with 1,3,5-Triaza-7-phosphaadamantane (PTA)

The aqueous medium self-assembly reactions of copper(II) nitrate with 1,3,5-triaza-7-phosphaadamantane (PTA) as a main ligand and sodium azide or iodide as an auxiliary ligand lead to the new water-soluble Cu(I) coordination polymer [Cu(μ-N 3 )(μ-PTA)] n ( 1 ) and monomer [CuI(PTA)(PTAH) 2 ]I 2 ·H 2 O ( 2 ) (PTAH = N-protonated form of PTA), with the PTA cages exhibiting the rare P,N- or the conventional P-coordination mode, respectively. Another hydrosoluble P-bound PTA derivative [Cu(PTA) 4 ](NO 3 )·6H 2 O ( 3 ) is furnished in the absence of any auxiliary ligand. The compounds have been characterized by IR and NMR spectroscopy, elemental and single crystal X-ray diffraction analyses which feature the formation of a unique one-dimensional (1D) coordination network in 1 composed of the {Cu 2 (μ-N 3 ) 2 } cores and PTA spacers, as well as 1D (in 2 ) and three-dimensional (3D) (in 3 ) supramolecular structures built from multiple N−H···N (PTAH/PTA) and O−H···N (H 2 O/PTA) H-bonds, respectively. The study broadens the still limited use of PTA as a spacer or building block for crystal engineering of metal−organic coordination and supramolecular networks, their nature being also dependent on the type of auxiliary ligand. Compound 1 represents the first example of a copper coordination polymer with PTA.