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Title: Light‐responsive and Protic Ruthenium Compounds Bearing Bathophenanthroline and Dihydroxybipyridine Ligands Achieve Nanomolar Toxicity towards Breast Cancer Cells †
ABSTRACT

We report new ruthenium complexes bearing the lipophilic bathophenanthroline (BPhen) ligand and dihydroxybipyridine (dhbp) ligands which differ in the placement of the OH groups ([(BPhen)2Ru(n,n′‐dhbp)]Cl2withn = 6 and 4 in 1Aand 2A, respectively). Full characterization data are reported for 1Aand 2Aand single crystal X‐ray diffraction for 1A. Both 1Aand 2Aare diprotic acids. We have studied 1A, 1B, 2A, and 2B(B = deprotonated forms) by UV‐vis spectroscopy and 1 photodissociates, but 2 is light stable. Luminescence studies reveal that the basic forms have lower energy3MLCT states relative to the acidic forms. Complexes 1Aand 2Aproduce singlet oxygen with quantum yields of 0.05 and 0.68, respectively, in acetonitrile. Complexes 1 and 2 are both photocytotoxic toward breast cancer cells, with complex 2 showing EC50light values as low as 0.50 μM with PI values as high as >200vs. MCF7. Computational studies were used to predict the energies of the3MLCT and3MC states. An inaccessible3MC state for 2Bsuggests a rationale for why photodissociation does not occur with the 4,4′‐dhbp ligand. Low dark toxicity combined with an accessible3MLCT state for1O2generation explains the excellent photocytotoxicity of 2.

 
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Award ID(s):
1828078 1919906 1800201 2102552
NSF-PAR ID:
10448412
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley-Blackwell
Date Published:
Journal Name:
Photochemistry and Photobiology
Volume:
98
Issue:
1
ISSN:
0031-8655
Page Range / eLocation ID:
p. 102-116
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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