Homodinuclear organometallics of ditopic N,N-chelates: Synthesis, reactivity and in vitro anticancer activity

Cavity-Containing [Fe2L3]4+ Helicates: An Examination of Host-Guest Chemistry and Cytotoxicity

“…However, the [Fe 2 ( L pyimR ) 3 ] 2+ systems are more effective overall with some of that family displaying nanomolar activities ( Kaner et al, 2016 ; Song et al, 2020 ). We have recently studied the cytotoxicity of a small family of dimetallic organometallic (Ru, Rh, Os, and Ir) complexes ( Steel et al, 2021a ) of L Pyim against the same series of cell lines enabling a more direct comparison ( Table 1 ). Both helicates displayed better activity than the dimetallic complexes and L Pyim across the range of cell lines.…”

“…MR conducted cytotoxicity studies and TABLE 1 | IC 50 values (µM) for L1 and L2 and the iron(II) cylinders against HCT116 (human colorectal carcinoma), NCI-H460 (human non-small cell lung carcinoma), SiHa (human cervical carcinoma), and SW480 (human colon adenocarcinoma) cancer cells as compared to cisplatin, expressed as mean ± standard error (n 3, incubation period 72 h). Steel et al (2021a) 21 ± 6 3 1 ± 4 4 2 ± 3 4 6 ± 5 rac-[Fe 2 (L Pyim ) 3 ](BF 4 ) 4 9 ± 2 1 0 ± 3 2 6 ± 4 2 8 ± 7 [(Rh(Cp*)Cl) 2 (L pyim )] Steel et al (2021a) 78 ± 21 >100 45 ± 4 7 3 ± 5 [Fe(H 2 O) 6 ](BF 4 ) 2 >200 184 ± 11 >500 >300 Cisplatin Tremlett et al (2019) 2.5 ± 0.3 0.80 ± 0.03 3.0 ± 0.6 8.1 ± 2.9 n.d., not determined due to the poor solubility of the compound.…”

Synthetic Strategy Towards Heterodimetallic Half-Sandwich Complexes Based on a Symmetric Ditopic Ligand

“…Recently, we reported the preparation of homodimetallic compounds of a symmetric, ditopic 2-pyridylimine-based ligand featuring a 1,4-diaminobenzene spacer ( Figure 1 , L DAB ), which is known to form stable coordination complexes ( Steel et al, 2021 ). The formation of these di-Ru, -Os, -Rh and -Ir compounds with two different ditopic ligands highlighted the ability to reliably obtain homodimetallic compounds in good yield ( Steel et al, 2021 ). The complexes also demonstrated a range of structural characteristics and cytotoxic activity ( Steel et al, 2021 ).…”

“…The formation of these di-Ru, -Os, -Rh and -Ir compounds with two different ditopic ligands highlighted the ability to reliably obtain homodimetallic compounds in good yield ( Steel et al, 2021 ). The complexes also demonstrated a range of structural characteristics and cytotoxic activity ( Steel et al, 2021 ). In the case of those homodimetallic complexes, the ligand was prepared before it was decorated with metal centers.…”

“…These structures were important as they highlighted the possibility for the rapid formation of a range of homo- and heterodimetallic species. Although the compounds had poor cytotoxicity in comparison to other dimetallic compounds ( Steel et al, 2021 ), synthetic alterations to the ditopic ligand being used could easily yield more potent metal-based chemotherapeutics. Alternatively, scaffold structures can be adopted to form dimetallic species of greater complexity.…”