pH-Responsive luminescence sensing, photoredox catalysis and photodynamic applications of ruthenium(II) photosensitizers bearing imidazo[4,5-f][1,10]phenanthroline scaffolds

Three-photon absorption iridium(iii) photosensitizers featuring aggregation induced emission

“…Photodynamic therapy, as a new cancer treatment method, can be accurately and effectively applied with very few side effects, 1 and the singlet oxygen ( 1 O 2 ) species generated in this process play a vital role in inducing apoptosis of cancer cells. [2][3][4] The photosensitizers, as important theranostic agents for photodynamic therapy, should have high production efficiency of reactive oxygen species and strong photobleaching resistance. Iridium(III) complexes are an important class of photosensiti-zers, owing to their strong spin-orbit coupling effect, tunable optical properties and rich excited state behavior, and have been widely applied in photodynamic therapy.…”

A fundamental role of the solvent polarity and remote substitution of the 2-(4-R-phenyl)-1H-imidazo[4,5-f][1,10]phenanthroline framework in controlling the ground- and excited-state properties of Re(i) chromophores [ReCl(CO)3(R-C6H4-imphen)]

“…1–20 Possessing the 1,10-phenanthroline unit with strong abilities to bind transition metals, imidazo[4,5- f ][1,10]phenanthrolines have also become very popular ligands for controlling the photophysical and antiproliferative behaviour of transition metal complexes. They have been combined with numerous transition metal ions including Cu( i ), 21–25 Cu( ii ), 26–28 Ru( ii ), 29–40 and Ir( iii ). 41–46 The vast majority of these coordination compounds have potential uses in anticancer therapy, 26–28,31,34–37,39–46 bioimaging, 32,47 the conversion of solar energy, 22,29 organic light-emitting diodes, 21,23,48–50 photoredox catalysis, 38,51,52 and luminescence sensing.…”

“…They have been combined with numerous transition metal ions including Cu( i ), 21–25 Cu( ii ), 26–28 Ru( ii ), 29–40 and Ir( iii ). 41–46 The vast majority of these coordination compounds have potential uses in anticancer therapy, 26–28,31,34–37,39–46 bioimaging, 32,47 the conversion of solar energy, 22,29 organic light-emitting diodes, 21,23,48–50 photoredox catalysis, 38,51,52 and luminescence sensing. 30,38,53–56 Surprisingly, little attention has been paid to Re( i ) carbonyl chromophores with 1 H -imidazo[4,5- f ][1,10]phenanthrolines, 47,49,57–66 in contrast to phenanthroline Re( i ) carbonyl complexes [Re(CO) 3 X(N∩N)] n + ( n = 0 or 1), which have a very rich history in coordination chemistry and largely contribute to the understanding of photophysical and light-induced electron-transfer and electronic energy-transfer processes.…”

“…41–46 The vast majority of these coordination compounds have potential uses in anticancer therapy, 26–28,31,34–37,39–46 bioimaging, 32,47 the conversion of solar energy, 22,29 organic light-emitting diodes, 21,23,48–50 photoredox catalysis, 38,51,52 and luminescence sensing. 30,38,53–56 Surprisingly, little attention has been paid to Re( i ) carbonyl chromophores with 1 H -imidazo[4,5- f ][1,10]phenanthrolines, 47,49,57–66 in contrast to phenanthroline Re( i ) carbonyl complexes [Re(CO) 3 X(N∩N)] n + ( n = 0 or 1), which have a very rich history in coordination chemistry and largely contribute to the understanding of photophysical and light-induced electron-transfer and electronic energy-transfer processes. 67–74 In this study, we present Re( i ) tricarbonyls with the 1 H -imidazo[4,5- f ][1,10]phenanthroline (imphen) functionalized with electron-donating amine groups attached to the imidazole ring via phenylene linkages.…”

A DFT study of the second-order nonlinear optical properties of Ru(ii) polypyridine complexes

“…Similarly, phenanthroline is a popular ligand that is coordinated with Ru(II) metal for creating NLO materials due to its special structural features, e.g., a large push-pull system with p-electron space, the existence of nitrogen atoms with a rigid and flat phenanthroline core, and switchable substituents to finely tune the NLO response. 28,29 Our group has investigated the second-order NLO properties of a series of 1,10-phenanthroline Ru(II) complexes theoretically. It was observed that the modification of ligand structures with electron acceptor groups enhanced the b tot value and quadratic NLO response on a molecular level.…”