TY - JOUR

T1 - Photophysics and photochemistry of a prospective light-activated anticancer dirhodium complex

AU - Meshcheryakova, V. a.

AU - Ershov, K. s.

AU - Baklanov, A. v.

AU - Kokorenko, A. a.

AU - Pozdnyakov, I. p.

AU - Tsentalovich, Yu. p.

AU - Zazulya, A. e.

AU - Vasilchenko, D. b.

AU - Polyakova, E. a.

AU - Melnikov, A. a.

AU - Chekalin, S. v.

AU - Glebov, E. m.

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

PY - 2025

Y1 - 2025

N2 - Dirhodium complexes Rh(II,II) with organic ligands are known to demonstrate light-induced cytotoxicity, combining both oxygen-dependent (like in the case of photodynamic therapy, PDT) and oxygen-independent (like in the case of photo-activated chemotherapy, PACT) anticancer activity. Photophysics and photochemistry of the previously reported light-activated anticancer dirhodium complex cis-[Rh2(μ-O2CCH3)2(dppn)2](O2CCH3)2 (dppn = benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine) were studied by means of several stationary (UV spectroscopy and capillary electrophoresis) and time-resolved (laser flash photolysis, ultrafast TA spectroscopy and direct singlet oxygen detection) methods. The only observed photochemical reaction is photoaquation with the release of an acetate ligand; its quantum yield is low (0.026%). The quantum yields of singlet oxygen formation in different solvents (D2O, CH3CN, and CD3OD) lie in the range (2–8)%, which is consistent with the presumably oxygen-independent pathway of light-induced cell-damage reported in the literature. Complicated behavior of intermediate absorption in the time interval from 100 fs to 20 μs was interpreted by “ladder” transitions between excited states of different nature, 1IL* → 3IL* → 3MLCT* → 3MC*. The lifetime of the longest-living excited state 3MC* is 6.2 μs. Estimations show that the oxygen-independent light-induced cytotoxic effect could be provided even without preliminary binding of the complex to the substrate.

AB - Dirhodium complexes Rh(II,II) with organic ligands are known to demonstrate light-induced cytotoxicity, combining both oxygen-dependent (like in the case of photodynamic therapy, PDT) and oxygen-independent (like in the case of photo-activated chemotherapy, PACT) anticancer activity. Photophysics and photochemistry of the previously reported light-activated anticancer dirhodium complex cis-[Rh2(μ-O2CCH3)2(dppn)2](O2CCH3)2 (dppn = benzo[i]dipyrido[3,2-a:2′,3′-c]phenazine) were studied by means of several stationary (UV spectroscopy and capillary electrophoresis) and time-resolved (laser flash photolysis, ultrafast TA spectroscopy and direct singlet oxygen detection) methods. The only observed photochemical reaction is photoaquation with the release of an acetate ligand; its quantum yield is low (0.026%). The quantum yields of singlet oxygen formation in different solvents (D2O, CH3CN, and CD3OD) lie in the range (2–8)%, which is consistent with the presumably oxygen-independent pathway of light-induced cell-damage reported in the literature. Complicated behavior of intermediate absorption in the time interval from 100 fs to 20 μs was interpreted by “ladder” transitions between excited states of different nature, 1IL* → 3IL* → 3MLCT* → 3MC*. The lifetime of the longest-living excited state 3MC* is 6.2 μs. Estimations show that the oxygen-independent light-induced cytotoxic effect could be provided even without preliminary binding of the complex to the substrate.

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-105005345199&origin=inward&txGid=1a562d8e5960c16448e1fb4a0b2b8a80

U2 - 10.1039/D5CP00435G

DO - 10.1039/D5CP00435G

M3 - Article

JO - Physical Chemistry Chemical Physics

JF - Physical Chemistry Chemical Physics

SN - 1463-9076

ER -