The Structures, Spectroscopic Properties, and Photodynamic Reactions of Three [RuCl(QN)NO]⁻Complexes (HQN = 8-Hydroxyquinoline and Its Derivatives) as Potential NO-Donating Drugs

Abstract

The structures and spectral properties of three ruthenium complexes with 8-hydroxyquinoline (Hhqn) and their derivatives 2-methyl-8-quinolinoline (H2mqn) and 2-chloro-8-quiolinoline (H2cqn) as ligands (QN = hqn, 2mqn, or 2cqn) were calculated with density functional theory (DFT) at the B3LYP level. The UV-Vis and IR spectra of the three [RuCl(QN)NO]− complexes were theoretically assigned via DFT calculations. The calculated spectra reasonably correspond to the experimentally measured spectra. Photoinduced NO release was confirmed through spin trapping of the electron paramagnetic resonance spectroscopy (EPR), and the dynamic process of the NO dissociation upon photoirradiation was monitored using time-resolved infrared (IR) spectroscopy. Moreover, the energy levels and related components of frontier orbitals were further analyzed to understand the electronic effects of the substituent groups at the 2nd position of the ligands on their photochemical reactivity. This study provides the basis for the design of NO donors with potential applications in photodynamic therapy.

Development of Novel β-Carboline/Furylmalononitrile Hybrids as Type I/II Photosensitizers with Chemo-Photodynamic Therapy and Minimal Toxicity

“…Therefore, we used the Gaussian 09 software for DFT calculation to confirm the above results (Figure ). , We first calculated the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of deprotonated and protonated 10f . As the Δ E (LUMO–HOMO) of 10f was 3.11 eV, it dropped to 2.98 eV after protonation under acidic conditions.…”

Structural and Photodynamic Studies on Nitrosylruthenium-Complexed Serum Albumin as a Delivery System for Controlled Nitric Oxide Release

“…This is similar to other nitrosylruthenium complexes with 8hydroxyquinoline derivatives, as reported previously. 94 Photolysis of the {Ru II -NO + } complexes could produce paramagnetic Ru(III) species upon NO release as the equation {Ru-NO} 6 + hν → Ru III -(solv) + NO. 95,96 The spectral analyses for the photodynamic reaction of nitrosylruthenium complexes establish a foundation for the design of NO donors with potential applications.…”