5 research outputs found
Mechanistic Study on the Photochemical âLight Switchâ Behavior of [Ru(bpy)<sub>2</sub>dmdppz]<sup>2+</sup>
[RuÂ(bpy)<sub>2</sub>dmdppz]<sup>2+</sup> (bpy = 2,2â˛-bipyridine
and dmdppz = 3,6-dimethyl dipyridylphenazine), a strained RuÂ(II) polypyridyl
complex, is a derivative of the well-known luminescent âlight
switchâ, [RuÂ(bpy)<sub>2</sub>dppz]<sup>2+</sup> (dppz = dipyridylphenazine).
[RuÂ(bpy)<sub>2</sub>dmdppz]<sup>2+</sup> is of interest because it
acts as a photochemical sensor and metalating agent for DNA. Here
we report a detailed study to elucidate the mechanism of ligand substitution
by investigating the photochemical reaction in a variety of solvents
and by determining the effects of different incoming ligands, the
incoming ligand concentration, and the temperature dependence. Results
from these studies indicate that the mechanism of substitution is
associative or interchange associative, in contrast with the dissociative
mechanism of other photolabile RuÂ(II) polypyridyl complexes
Combining a Ru(II) âBuilding Blockâ and Rapid Screening Approach to Identify DNA Structure-Selective âLight Switchâ Compounds
A chemically
reactive RuÂ(II) âbuilding blockâ, able
to undergo condensation reactions with substituted diamines, was utilized
to create a small library of luminescent âlight switchâ
dipyrido-[3,2-<i>a</i>:2â˛,3â˛-<i>c</i>] phenazine (dppz) complexes. The impact of substituent identity,
position, and the number of substituents on the light switch effect
was investigated. An unbiased, parallel screening approach was used
to evaluate the selectivity of the compounds for a variety of different
biomolecules, including protein, nucleosides, single stranded DNA,
duplex DNA, triplex DNA, and G-quadruplex DNA. Combining these two
approaches allowed for the identification of hit molecules that showed
different selectivities for biologically relevant DNA structures,
particularly triplex and quadruplex DNA
Photoactive Ru(II) Complexes With Dioxinophenanthroline Ligands Are Potent Cytotoxic Agents
Two
novel strained rutheniumÂ(II) polypyridyl complexes containing a 2,3-dihydro-1,4-dioxinoÂ[2,3-<i>f</i>]-1,10-phenanthroline (dop) ligand selectively ejected
a methylated ligand when irradiated with >400 nm light. The best
compound exhibited a 1880-fold increase in cytotoxicity in human cancer
cells upon light-activation and was 19-fold more potent than the well-known
chemotherapeutic, cisplatin
Photoactive Ru(II) Complexes With Dioxinophenanthroline Ligands Are Potent Cytotoxic Agents
Two
novel strained rutheniumÂ(II) polypyridyl complexes containing a 2,3-dihydro-1,4-dioxinoÂ[2,3-<i>f</i>]-1,10-phenanthroline (dop) ligand selectively ejected
a methylated ligand when irradiated with >400 nm light. The best
compound exhibited a 1880-fold increase in cytotoxicity in human cancer
cells upon light-activation and was 19-fold more potent than the well-known
chemotherapeutic, cisplatin
Photoactive Ru(II) Complexes With Dioxinophenanthroline Ligands Are Potent Cytotoxic Agents
Two
novel strained rutheniumÂ(II) polypyridyl complexes containing a 2,3-dihydro-1,4-dioxinoÂ[2,3-<i>f</i>]-1,10-phenanthroline (dop) ligand selectively ejected
a methylated ligand when irradiated with >400 nm light. The best
compound exhibited a 1880-fold increase in cytotoxicity in human cancer
cells upon light-activation and was 19-fold more potent than the well-known
chemotherapeutic, cisplatin