Synthesis and characterization of 1,3,5-triaza-7-phosphaadamantane based water-soluble ligands

Four new water-soluble bidentate ligands, namely, (cyclopentadienyl)ethyl-1,3,5-triaza-7-phosphadamantane (1), 1,2-bis-(1,3,5-triaza-7-phosphaadamantan-6-yl) ethane (2), 1,3-bis-(1,3,5-triaza-7-phosphaaadamantan-6-yl) propane (3) and 1,4-bis-(1,3,5-triaza-7-phosphaadamantan-6-yl) butane (4) have been synthesized and characterized by multi-nuclear NMR (H-1, C-13 and P-31), elemental analysis and mass spectrometry. Compound 1 was synthesized by using two different synthetic routes in excellent yields and is also the first example of water-soluble chelating cyclopentadienyl ligand containing 1,3,5-triaza-7-phosphaadamantane.