Water-Soluble Phosphanes Derived from 1,3,5-Triaza-7-phosphaadamantane and Their Reactivity towards Gold(I) Complexes



New water-soluble phosphanes derived from 1,3,5-triaza-7-phosphaadamantane, namely, [PTA–R]Br (R = –CH2C≡CH, –CH2CONH2, –CH2COOH), are described. Coordination of these phosphanes and their previously reported counterparts (R = –CH2CN, –CH2Ph and –CH2COOMe) to gold(I) salts gives water-soluble derivatives with chlorido, bromido or pentafluorophenyl coligands. The luminescence properties of all new compounds have been studied in the solid state and compared with the respective free PTA ligands. [PTA–CH2Ph]Br, [PTA–CH2COOMe]Br and [AuBr(PTA–CH2Ph)]Br have also been characterised by X-ray diffraction analysis. Some of the new gold(I) compounds exhibit strong antiproliferative effects in the human ovarian carcinoma cell line A2780 and its cisplatin-resistant variant (A2780cisR). A balanced relationship between lipophilicity and hydrophilicity is found in these derivatives, with distribution coefficients (log D7.4) that range from 0.14 to –0.40.