IntroducingN-,P-, andS-donor leaving groups: an investigation of the chemical and biological properties of ruthenium, rhodium and iridium thiopyridone piano stool complexes

Abstract

The impact of different leaving groups on stability and anticancer properties of 15 thiopyridone-based RuII, RhIII or IrIII organometallics has been investigated.

Piano-Stool Ruthenium(II) Complexes with Delayed Cytotoxic Activity: Origin of the Lag Time

“…Conversion of 2 CI 2 iPr to a cyclometalated species is much slower; therefore, evolution of the IC 50 value is not observed within a period of 7 days (see Table ). It can be pointed out that the observed IC 50 values, ranging from 1.72 to 5.82 μM, are comparable to data reported in the literature for various types of piano-stool ruthenium­(II) complexes. − However, it can be stressed that the IC 50 values for 3 Cl iPr , 3 I iPr and 3 dmso iPr , given in Table , were determined after 24 h of incubation with cells, whereas most of the IC 50 values found in the literature were obtained after a drug-exposure time of 48, 72, or 96 h; − hence, the low-micromolar IC 50 values achieved after 24 h of incubation with 3 CI iPr , 3 I iPr , and 3 dmso iPr indicate that they are highly cytotoxic. Notable activities after 24 h of incubation have been described for tethered, acylpyrazolonato-containing, or amino-oxime-based half-sandwich ruthenium­(II) complexes, but 3 Cl iPr , 3 I iPr , and 3 iPr dmso are comparatively more efficient.…”

Theoretical insights into the photovoltaic properties of ruthenium(ii) bipyridyl photosensitizers through variation of the anchoring groups

“…(2) This complex is free of anchoring groups, so by attaching different anchoring groups to the bpy ligands, the efficiency of this complex can be improved as a ruthenium(II) sensitizer in DSSC applications. In this context, the Ru-dyes (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11) were designed by replacing the hydrogen atoms of the bpy ligands with electron-donating and electronwithdrawing anchors in the reference dye (see Fig. 1).…”

“…For further insight into the electronic structure of the [Ru(bpy) 2 (NCS) 2 ] derivatives, natural bond orbital (NBO) analysis was conducted under vacuum and in the solvent phase. This allowed for the computation of the highest occupied molecular orbital energies (E HOMO ), the lowest unoccupied molecular orbital energies (E LUMO ) and the HOMO-LUMO energy gap (HLG = E LUMO -E HOMO ) of Ru-dyes (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11) in both phases, which are presented in Table 1. It is evident that the HOMO energies decreased from vacuum to solvent media, indicating stabilization of the HOMO, while the LUMO energies showed a slight increase, signifying destabilization of the LUMO.…”

“…8,9 Sensitizers of polypyridyl complexes have the formula ML 2 (X) 2 , where M is the metallic center, such as Re(I), Ru(II) or Os(II), L is related to 4,4 0 -dicarboxy-2,2 0 -bipyridine ligands, and X is usually a thiocyanate (SCN À ) ligand. [10][11][12][13] Among all, ruthenium(II) polypyridyl complexes are known to exhibit extraordinary optical and electronic properties; for example, the black dye, 14 N3, 15 and N719 16 represent the best efficiency. The great interest in these complexes corresponds to their additional and anchoring ligands, which are responsible for the attachment to the semiconductor (typically TiO 2 or ZnO) and absorption of light.…”

Cell nucleus localization and high anticancer activity of quinoline–benzopyran rhodium(iii) metal complexes as therapeutic and fluorescence imaging agents

“…1,6 The first Rh( iii ) complex, [Rh 2 (CH 3 COO) 4 (H 2 O) 2 ], was investigated as an anticancer drug against various tumor cells over 40 years ago. 1,7 Various Rh( iii ) complexes of well-known CDDP analogs have demonstrated contrasting antiproliferative activities, including bidentate N -(3-halidophenyl)picolinamide Rh( iii ) dihalido complexes 1 , 1 ispinesib-derived Rh( iii ) trans diiodido complex 2 , 6 a curcumin-bisdemethoxycurcumin Rh( iii ) compounds 3 and 4 , 9,10 imidazo[4,5- f ][1,10]phenanthroline Rh( iii ) complexes 5 and 6 , 11,12 2-(2-pyridyl)benzimidazole half-sandwich Rh( iii ) complex 7 , 13 1-methylimidazole Rh( iii ) complex 8 , 14 1,2,4-triazole Rh( iii ) complex 9 , 15 1,8-naphthalimide derived Rh( iii ) complex 10 , 16 thiabendazole Rh( iii ) biscyclometallated complex 11 , 17 rhodium( i ) N-heterocyclic carbene complex 12 , 18 hydroxamic acid Rh( iii ) complex 13 , 19 organometallic Rh( iii ) half-sandwich anticancer complex 14 20 and other analogs 15–20 , 21–26 which have been found to be active against various cancer types. However, the affirmative targeted design of Rh( iii ) compounds has been barely investigated in clinical therapy, thereby increasing the possibility of developing novel Rh( iii ) chemotherapeutics that overcome CDDP resistance and have fewer side effects (Chart 1).…”