Research Information System
Journal of Molecular Structure, vol.1365, 2026 (SCI-Expanded, Scopus)
In this study, the dithiophosphonate precursor 2,4-bis(2,4-dimethoxyphenyl)-1,3-dithia-2,4-diphosphetane-2,4-disulfide (SAV-A2) was used as the starting material. Its reaction with various alcohols produced a new series of dithiophosphonic acids, HLn [RRnP(S)SH], where R = 2,4-dimethoxyphenyl and Rn= Ln (L1= n‑butyl‑, L2 = 2-pentyl-, L3 = 3-pentyl-, L4 = benzyl-). These crude acids were subsequently stabilized with ammonia gas to afford the corresponding ammonium salts ([NH4Ln]), which served as precursor ligands for Ni(II) complex formation ([Ni(Ln)2]). Furthermore, the reaction of these complexes with 1,10-phenanthroline (phen) yielded six-coordinate Ni(II) complexes, [Ni(phen)3][(Ln)2]. The structures of the compounds so prepared were elucidated by spectroscopic techniques (1H-, 13C-, and 31P-NMR, FT-IR, and mass spectrometry) and magnetic susceptibility measurements (for [Ni(phen)3][(Ln)2]). The molecular structures of the [Ni(Ln)2] complexes were confirmed by single-crystal X-ray diffraction. The antiproliferative activities of the compounds, except for [Ni(Ln)2], were evaluated by MTT assay after 48 h of incubation. The compounds exhibited generally low cytotoxicity within the tested concentration range, with [Ni(phen)3][(L2)2] showing the highest activity against the DLD-1 cell line. The photophysical behaviour of all compounds was examined using UV–visible absorption and steady-state fluorescence spectroscopy.