A new family of iron(II)-cyclopentadienyl compounds shows strong activity against colorectal and triple negative breast cancer cells

The following is available online, Figure S1—1H NMR spectrum of complexes 6, in acetone-d6, Table S1. Bond lengths [Å] and angles [°] for [Fe(η5-Cp)(CO)(PhCN)(PPh3)][CF3SO3] 1, [Fe(η5-Cp)(CO)(p-NCPhNH2)(PPh3)][CF3SO3] 4 and [Fe(η5-Cp)(CO)(p-NCPhBr)(PPh3)][CF3SO3] 5, Table S2. Relevant TD-DFT (PBE0) excitation energies (λ), oscillator strengths (f) and compositions (only those > 5% are shown), for complexes 1–6, compared with experimental data (λexp). Both calculated and experimental values were obtained in dichloromethane, Figure S2—UV-Vis spectra of complexes 1–6 in DMSO along the 24 h study, Figure S3—UV-Vis spectra of complexes 1–6 in DMSO/DMEM mixture along the 24 h study and its variation plot (%) (bottom), Figure S4. ‘FeCp’ compounds affect the colony formation ability of SW480 cell line. Analysis of the colony formation ability, after 48 h of incubation with 1/4 IC50 and IC50, in SW480 cell line. Representative images of colony formation assay in SW480 cell line, Figure S5. ‘FeCp’ compounds induce apoptosis colorectal cancer-derived cell line. Apoptotic cell death was analyzed by Annexin V fluorescein isothiocyanate (AV-FITC) and propidium iodide (PI) assay in SW480 cells, after incubation with IC50 and 2×IC50 concentrations for 48 h. Representative histograms of SW480 cell line double stained with AV and PI, Table S4. Crystal data and structure refinement for [Fe(η5-Cp)(CO)(PhCN)(PPh3)][CF3SO3] 1, [Fe(η5-Cp)(CO)(p-NCPhNH2)(PPh3)][CF3SO3] 4 and [Fe(η5-Cp)(CO)(p-NCPhBr)(PPh3)][CF3SO3] 5. A family of compounds with the general formula [Fe(η 5 -C 5 H 5 )(CO)(PPh 3 )(NCR)] + has been synthesized (NCR = benzonitrile ( 1 ); 4-hydroxybenzonitrile ( 2 ); 4-hydroxymethylbenzonitrile ( 3 ); 4-aminobenzonitrile ( 4 ); 4-bromobenzonitrile ( 5 ); and, 4-chlorocinnamonitrile ( 6 )). All of the compounds were obtained in good yields and were completely characterized by standard spectroscopic and analytical techniques. Compounds 1 , 4 , and 5 crystallize in the monoclinc P21/c space group and packing is determined by short contacts between the phosphane phenyl rings and cyclopentadienyl (compounds 1 and 4 ) or π-π lateral interactions between the benzonitrile molecules (complex 5 ). DFT and TD-DFT calculations were performed to help in the interpretation of the experimental UV-Vis. data and assign the electronic transitions. Cytotoxicity studies in MDA-MB-231 breast and SW480 colorectal cancer-derived cell lines showed IC 50 values at a low micromolar range for all