Synthesis, characterization and molecular structures of the hybrid organic–inorganic salts of N-alkyl-1,3,5-triaza-7-phosphaadamantane (alkyl = methyl, ethyl) and tetra(isothiocyanato)cobalt(II)

The reactions of CoCl2 with the alkylated aminophosphine N-alkyl-1,3,5-triaza-7-phosphaadamantane iodide [PTA-R]I (R = Me, Et) and NaSCN, in an ethanolic medium at ambient temperature, lead to the self-assembly formation of the hybrid 2:1 organic–inorganic salts [PTA-R]2[Co(NCS)4] (R = Me (1); Et (2)), which have been characterized by IR spectroscopy, FAB+-MS, elemental and single crystal X-ray diffraction structural analyses. The molecular structures bear two cage-like [PTA-R]+ cations and one discrete tetrahedral [Co(NCS)4]2− anion. Adjacent anions are linked via repeating weak intermolecular S⋯S contacts forming 1D supramolecular inorganic networks, acting as hosts for the [PTA-R]+ guests. 1 and 2 represent the first structurally characterized examples of compounds where any uncoordinated cage-like PTA derivative acts as a component of a hybrid organic–inorganic material.