Understanding the photophysical properties of rhenium(i) compounds coordinated to 4,7-diamine-1,10-phenanthroline: synthetic, luminescence and biological studies

Abstract

The photophysical properties of fac-[Re(L)(Am2phen)(CO)3]0/+ provided new insights into excited-state deactivation through an unusual inversion between two MLCT excited states.

Cytotoxic properties of rhenium(i) tricarbonyl complexes of N-heterocyclic carbene ligands

“…50 Solvent effects were included using the CPCM model. 54 The calculated structures of complexes 7–14 are shown in Fig. 7 and the bond dissociation energies, as well as the bond length and quantum topological descriptors for the Re–O (carboxylate) bonds of these complexes, are listed in Table 2.…”

“…As the Re(I) complexes of NHC ligands have been previously shown to display luminescence, [52][53][54] the photophysical properties of Re(I) complexes 9, 10, 13 and 14 were investigated.…”

“…The Re(I) complexes of the pyridyl-imidazolylidene ligand (1, 9 and 10) show strong absorption bands at ∼275 nm and ∼340 nm and based on previous studies on related compounds, the low energy absorption band (320-460 nm) can be assigned to metal-to-ligand charge transfer (MLCT) transitions, while the absorption bands at higher energy (250-320 nm) are likely to correspond to the ligand-to-ligand charge transfer (LLCT) and intra-ligand transition (ILCT). 52,[54][55][56] The Re(I) bis-imidazolylidene complexes (2, 13 and 14) display an intense absorption band at ∼320 nm, which can be assigned to MLCT transitions. These complexes also display a weak shoulder at ∼350 nm.…”

Photoactive and Luminescent Transition Metal Complexes as Anticancer Agents: A Guiding Light in the Search for New and Improved Cancer Treatments

“…In fact, in our search, all examples of rhenium luminescent anticancer complexes were based on this [Re(I)(CO) 3 ] + parent complex. Research exploring the relationship between structure, luminescence, chemotherapeutics, and pharmacokinetics has been undertaken, which explored the effects of the charge, lipophilicity [91], and basicity of ligands [90]. Although the rhenium(I) complexes studied were not particularly cytotoxic, the positively charged complex was more cytotoxic than the non-charged, which was explained by the former's increased lipophilicity [91].…”

“…Research exploring the relationship between structure, luminescence, chemotherapeutics, and pharmacokinetics has been undertaken, which explored the effects of the charge, lipophilicity [91], and basicity of ligands [90]. Although the rhenium(I) complexes studied were not particularly cytotoxic, the positively charged complex was more cytotoxic than the non-charged, which was explained by the former's increased lipophilicity [91]. The axial NˆN ligand was reported to have negative correlations with luminescent quantum yields and energy, but no correlation with cytotoxicity was observed [92].…”