The First Copper Complexes Bearing the 1,3,5‐Triaza‐7‐phosphaadamantane (PTA) Ligand

Abstract

AbstractThe CuI compound [Cu(PTAH)4](NO3)5 (1) {PTAH = N‐protonated form of 1,3,5‐triaza‐7‐phosphaadamantane (PTA)} was easily prepared by reacting hydrated Cu(NO3)2 and PTA in aqueous acidic solution at room temperature. Further treatment of 1 with sodium hydroxide in water led to an unprotonated PTA derivative [Cu(PTA)4](NO3) (2). Both compounds are water‐soluble and air‐stable, and were characterized by IR, 1H‐, 13C{1H}‐, 31P{1H}‐ and 63Cu NMR spectroscopy, FAB‐MS(+), elemental and single‐crystal X‐ray diffraction structural analyses. They exhibit a nearly regular tetrahedral coordination environment about each copper centre filled by the phosphorus atoms of the four PTAH/PTA moieties, which show distinct and unusual geometrical arrangements if viewed along the P–Cu bonds. The 31P{1H}‐ and 63Cu NMR spectra of 2 in D2O solution show spin coupling between the 31P and 63Cu nuclei at room temperature. These compounds represent the first examples of Cu complexes bearing PTA or any derived ligand with a cagelike PTA core and expand the restricted family of aqua‐soluble copper phosphane complexes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)