Water-Soluble Rhenium Phosphine Complexes Incorporating the Ph2C(X) Motif (X = O–, NH–): Structural and Cytotoxicity Studies

• Published in: Inorganic chemistry Vol. 59; no. 4; pp. 2367 - 2378
• Main Authors: Alshamrani, Abdullah F, Prior, Timothy J, Burke, Benjamin P, Roberts, David P, Archibald, Stephen J, Higham, Lee J, Stasiuk, Graeme, Redshaw, Carl
• Format: Journal Article
• Language: English
• Published: American Chemical Society 17.02.2020
• ISSN: 0020-1669; 1520-510X
• DOI: 10.1021/acs.inorgchem.9b03239

Reaction of [ReOCl3(PPh3)2] or [ReO2I­(PPh3)2] with 2,2′-diphenylglycine (dpgH2) in refluxing ethanol afforded the air-stable complex [ReO­(dpgH)­(dpg)­(PPh3)] (1). Treatment of [ReO­(OEt)­I2(PPh3)2] with 1,2,3-triaza-7-phosphaadamantane (PTA) afforded the complex [ReO­(OEt)­I2(PTA)2] (2). Reaction of [ReOI2(PTA)3] with dpgH2 led to the isolation of the complex [Re­(NCPh2)­I2(PTA)3]·0.5EtOH (3·0.5EtOH). A similar reaction but using [ReOX2(PTA)3] (X = Cl, Br) resulted in the analogous halide complexes [Re­(NCPh2)­Cl2(PTA)3]·2EtOH (4·2EtOH) and [Re­(NCPh2)­(PTA)3Br2]·1.6EtOH (5·1.6EtOH). Using benzilic acid (2,2′-diphenylglycolic acid, benzH) with 2 afforded the complex [ReO­(benz)2(PTA)]­[PTAH]·EtOH (6·EtOH). The potential for the formation of complexes using radioisotopes with relatively short half-lives suitable for nuclear medicine applications by developing conditions for [Re­(NCPh2)­(dpg)­I­(PTA)3] (7)­[ReO4]− in a 4 h time scale was investigated. A procedure for the technetium analog of complex [Re­(NCPh2)­I2(PTA)3] (3) from 99mTc­[TcO4]− was then investigated. The molecular structures of 1–7 are reported; complexes 3–7 have been studied using in vitro cell assays (HeLa, HCT116, HT-29, and HEK 293) and were found to have IC50 values in the range of 29–1858 μM.