Synthesis and Biological Evaluation of Organometallic Complexes Bearing Bis‐1,8‐naphthalimide Ligands

Abstract

Organometallic N-heterocyclic carbene (NHC) complexes with intercalating bis-naphthalimide ligands were prepared and evaluated biologically. Cytotoxic effects against tumor cells or bacteria were strongly ligand dependent with minor influence of the metal (Ag, Ru, Rh, Au) centers. Complex 8b with a rhodium(I) NHC moiety was studied in more detail for its DNA interacting properties in comparison to the metal [a] 3108 Dichloro[1,3-Bis(3-{1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl}propyl)-1H-3λ 4 -imidazole-2-ylidene] (η 6 -p-cymene) Ruthenium(II) (9a): Yield: 0.052 g (0.06 mmol, 38 %) dark red solid; melting point: 218-220°C. 1 H NMR (CDCl 3 see Figure S10): δ = 8.58 (dd, 3 J = 7.3, 4 J = 1.1 Hz, 4 H, ArH 2/7 ), 8.19 (dd, 3 J = 8.4, 4 J = 1.0 Hz, 4 H, ArH 4/5 ), 7.73 (dd, 3 J = 8.2, 3 J = 7.2 Hz, 4 H, ArH 3/6 ), 7.09 (s, 2 H, Eur. J. Inorg. Chem. 2018, 3104-3112 www.eurjic.org

Using Room Temperature Phosphorescence of Gold(I) Complexes for PAHs Sensing

“…The heavy atom effect on room temperature phosphorescence of gold(I) naphthalimide complexes is reported herein for the first time although it has previously been observed in platinum complexes, with the similar vibronically structured shape [ 39 ]. Previous luminescent studies with other gold(I)–napthalimide complexes contain N -substituted napthalimide chromophores and display pure fluorescence emission [ 22 , 23 , 24 , 25 , 26 ]. In our cases, the naphthalimide group does not present any substitution, being thus less bulky.…”

“…In this way, gold(I) emerges as a new route to obtain RTP NI-complexes, since it is well known to enhance intersystem crossing and triplet state population [ 18 , 19 , 20 , 21 ]. Nevertheless, although there are few examples of gold(I)–NI complexes in the literature, they present fluorescence emission but not phosphorescence [ 4 , 22 , 23 , 24 , 25 , 26 ].…”

Current Developments of N-Heterocyclic Carbene Au(I)/Au(III) Complexes toward Cancer Treatment

“…Based on the same idea of distortion of DNA, metal complexes bearing intercalative or partially intercalative ligands (e.g., planar aromatic moieties with π-π stacking ability) have been extensively explored [ 83 , 87 ]. Au(I/III) complexes bearing various NHC ligands and/ or other intercalative ligands have been in the spotlight in the last decade, suggesting an alternative to cancer treatment [ 22 , 46 , 88 , 89 , 90 , 91 ].…”

Unveiling Luminescent IrI and RhI N‐Heterocyclic Carbene Complexes: Structure, Photophysical Specifics, and Cellular Localization in the Endoplasmic Reticulum

“…In this respect, complexes of the overall formula [M(COD)(NHC)X] (where M=Rh or Ir, COD=1,5‐cyclooctadiene, NHC=N‐heterocyclic carbene, and X=halide) represent the majority of complexes investigated in the field. The literature provides several examples of this complex class that have shown promising cytotoxic activities against several cancer cell lines [18–31] with IC 50 values ranging between 600 n m [21] and more than 100 μ m [29] . A direct comparison of the general trend predicts that complexes with a Rh I center are more active than their Ir I counterparts, [18] and that the activity is strongly influenced by the structure of the NHC ligand, potentially accounting for differences in the cellular uptake of the respective complex [25, 29] .…”