TY - JOUR
T1 - Oxygen-Sensing Chemiluminescent Iridium(III) 1,2-Dioxetanes
T2 - Unusual Coordination and Activity
AU - Kagalwala, Husain N.
AU - Bueno, Lorena
AU - Wanniarachchi, Hashini
AU - Unruh, Daniel K.
AU - Hamal, Khagendra B.
AU - Pavlich, Cyprian I.
AU - Carlson, Graham J.
AU - Pinney, Kevin G.
AU - Mason, Ralph P.
AU - Lippert, Alexander R.
N1 - Publisher Copyright:
© 2022 Wiley-VCH GmbH.
PY - 2023/1
Y1 - 2023/1
N2 - Next generation chemiluminescent iridium 1,2-dioxetane complexes have been developed which consist of the Schaap's 1,2-dioxetane scaffold directly attached to the metal center. This was achieved by synthetically modifying the scaffold precursor with a phenylpyridine moiety, which can act as a ligand. Reaction of this scaffold ligand with the iridium dimer [Ir(BTP)2(μ-Cl)]2 (BTP=2-(benzo[b]thiophen-2-yl)pyridine) yielded isomers which depict ligation through either the cyclometalating carbon or, interestingly, the sulfur atom of one BTP ligand. Their corresponding 1,2-dioxetanes display chemiluminescent responses in buffered solutions, exhibiting a single, red-shifted peak at 600 nm. This triplet emission was effectively quenched by oxygen, yielding in vitro Stern-Volmer constants of 0.1 and 0.009 mbar−1 for the carbon-bound and sulfur compound, respectively. Lastly, the sulfur-bound dioxetane was further utilized for oxygen sensing in muscle tissue of living mice and xenograft models of tumor hypoxia, depicting the ability of the probe chemiluminescence to penetrate biological tissue (total flux ∼106 p/s).
AB - Next generation chemiluminescent iridium 1,2-dioxetane complexes have been developed which consist of the Schaap's 1,2-dioxetane scaffold directly attached to the metal center. This was achieved by synthetically modifying the scaffold precursor with a phenylpyridine moiety, which can act as a ligand. Reaction of this scaffold ligand with the iridium dimer [Ir(BTP)2(μ-Cl)]2 (BTP=2-(benzo[b]thiophen-2-yl)pyridine) yielded isomers which depict ligation through either the cyclometalating carbon or, interestingly, the sulfur atom of one BTP ligand. Their corresponding 1,2-dioxetanes display chemiluminescent responses in buffered solutions, exhibiting a single, red-shifted peak at 600 nm. This triplet emission was effectively quenched by oxygen, yielding in vitro Stern-Volmer constants of 0.1 and 0.009 mbar−1 for the carbon-bound and sulfur compound, respectively. Lastly, the sulfur-bound dioxetane was further utilized for oxygen sensing in muscle tissue of living mice and xenograft models of tumor hypoxia, depicting the ability of the probe chemiluminescence to penetrate biological tissue (total flux ∼106 p/s).
KW - Schaap dioxetanes
KW - chemiluminescence
KW - in vivo imaging
KW - iridium complexes
KW - oxygen sensing
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U2 - 10.1002/anse.202200085
DO - 10.1002/anse.202200085
M3 - Article
C2 - 37006671
AN - SCOPUS:85145333973
SN - 2629-2742
VL - 3
JO - Analysis and Sensing
JF - Analysis and Sensing
IS - 1
M1 - e202200085
ER -