Influence of the substituent on the phosphine ligand in novel rhenium(i) aldehydes. Synthesis, computational studies and first insights into the antiproliferative activityElectronic supplementary information (ESI) available: Characterization of new dicarbonyl phosphine aldehydes of rhenium(i); cytotoxic studies. CCDC 1812999-1813001. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c8dt03160f

Cyrhetrenyl aldehyde derivatives [(η 5 -C 5 H 4 CHO)Re(CO) 2 PR 3 ] with R = methyl (Me, 2a ), phenyl (Ph, 2b ), and cyclohexyl (Cy, 2c ) were synthesized by a photochemical reaction from the starting material [(η 5 -C 5 H 4 CHO)Re(CO) 3 ] ( 1 ) and the corresponding phosphines. The complexes were fully characterized by FT-IR, 1 H, 13 C and 31 P NMR spectroscopy, elemental analysis and mass spectrometry. The molecular structures of 2a-c have also been determined. Electronic structure calculations by TD-DFT and electrochemical studies are in sound agreement with the effect of the substitution of one carbonyl group by a phosphine ligand. Additionally, the antiproliferative activity of complexes 1 and 2a-c was studied on the human cancer cell lines HT-29 and PT-45 using an MTT assay. Out of all new compounds, only the triphenylphosphine derivative 2b exhibited pronounced cytotoxic effects on both cell lines, being ca. 1.5 times more potent than cisplatin. Cyrhetrenyl phosphine derivatives were synthesized and evaluated as potential anticancer agents. Electrochemical and computational studies were carried out.