TY - JOUR

T1 - Photoaquation of cis-[Rh(dppz)(phen)Cl2]Cl complex prospective as potential light-activated anti-cancer agent

AU - Malakhova, Iuliia

AU - Polyakova, Evgenia

AU - Vasilchenko, Danila

AU - Grivin, Vjacheslav

AU - Pozdnyakov, Ivan

AU - Kokorenko, Andrei

AU - Melnikov, Alexei

AU - Chekalin, Sergei

AU - Glebov, Evgeni

N1 - The work was supported by the Russian Science Foundation (Grant № 23-13-00226).

PY - 2024/7/1

Y1 - 2024/7/1

N2 - The photoactivated drug usage in anti-cancer therapy, the working mechanism of which doesn't rely on the formation of reactive oxygen species, allows reducing damage to healthy tissue by controlling toxicity. For instance, light-activated Rh(III) complexes show nuclease activity after irradiation with UV and visible light. However, literature analysis shows a lack of descriptions of basic photochemical mechanisms. Here we report the study of cis-[Rh(dppz)(phen)Cl2]Cl (DPPZPHEN, dppz is dipyrido[3,2-a:2′,3′-c]phenazine, phen is 1,10-phenanthroline) photochemistry in water solutions using stationary photolysis, nanosecond laser flash photolysis and ultrafast pump–probe spectroscopy. After the irradiation with 308 nm light, DPPZPHEN undergoes aquation, which results in the substitution of one chloride ligand by a water molecule and leads to the formation of [Rh(dppz)(phen)(H2O)Cl]Cl2. UV–vis spectra of complex and capillary electrophoresis data were collected and discussed. Laser flash photolysis (355 nm) demonstrates intermediate absorption attributed to the lowest electronic excited state (triplet) of the initial complex. The study of primary photophysical processes showed a rather complicated behavior of transient absorption, which could be described by a set of four exponential functions. The early photophysical processes were described by the scheme including the formation of two excited states of different natures, namely a dppz-based IL state and an LMCT state.

AB - The photoactivated drug usage in anti-cancer therapy, the working mechanism of which doesn't rely on the formation of reactive oxygen species, allows reducing damage to healthy tissue by controlling toxicity. For instance, light-activated Rh(III) complexes show nuclease activity after irradiation with UV and visible light. However, literature analysis shows a lack of descriptions of basic photochemical mechanisms. Here we report the study of cis-[Rh(dppz)(phen)Cl2]Cl (DPPZPHEN, dppz is dipyrido[3,2-a:2′,3′-c]phenazine, phen is 1,10-phenanthroline) photochemistry in water solutions using stationary photolysis, nanosecond laser flash photolysis and ultrafast pump–probe spectroscopy. After the irradiation with 308 nm light, DPPZPHEN undergoes aquation, which results in the substitution of one chloride ligand by a water molecule and leads to the formation of [Rh(dppz)(phen)(H2O)Cl]Cl2. UV–vis spectra of complex and capillary electrophoresis data were collected and discussed. Laser flash photolysis (355 nm) demonstrates intermediate absorption attributed to the lowest electronic excited state (triplet) of the initial complex. The study of primary photophysical processes showed a rather complicated behavior of transient absorption, which could be described by a set of four exponential functions. The early photophysical processes were described by the scheme including the formation of two excited states of different natures, namely a dppz-based IL state and an LMCT state.

KW - Photo-Activated Chemotherapy

KW - Photochemistry

KW - Photophysics

KW - Rh(III) complexes

KW - Ultrafast TA spectroscopy

UR - https://www.mendeley.com/catalogue/44518806-8720-389a-b967-db34e919daa2/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85188740720&origin=inward&txGid=c6e3ecf60a7168dc7bc5efa7b0e492cf

U2 - 10.1016/j.jphotochem.2024.115621

DO - 10.1016/j.jphotochem.2024.115621

M3 - Article

VL - 452

JO - Journal of Photochemistry and Photobiology A: Chemistry

JF - Journal of Photochemistry and Photobiology A: Chemistry

SN - 1010-6030

M1 - 115621

ER -