Abstract
The UV-light-induced CO release characteristics of a series of ruthenium(II) carbonyl complexes of the form trans-Cl[RuLCl2(CO)2] (L = 4,4′-dimethyl-2,2′-bipyridine, 4′-methyl-2,2′-bipyridine-4-carboxylic acid, or 2,2′-bipyridine-4,4′-dicarboxylic acid) have been elucidated using a combination of UV-vis absorbance and Fourier transform infrared spectroscopies, multivariate curve resolution alternating least-squares analysis, and density functional theory calculations. In acetonitrile, photolysis appears to proceed via a serial three-step mechanism involving the sequential formation of [RuL(CO)(CH3CN)Cl2], [RuL(CH3CN)2Cl2], and [RuL(CH3CN)3Cl]+. Release of the first CO molecule occurs quickly (k1 ≫ 3 min-1), while release of the second CO molecule proceeds at a much more modest rate (k2 = 0.099-0.17 min-1) and is slowed by the presence of electron-withdrawing carboxyl substituents on the bipyridine ligand. In aqueous media (1% dimethyl sulfoxide in H2O), the two photodecarbonylation steps proceed much more slowly (k1 = 0.46-1.3 min-1 and k2 = 0.026-0.035 min-1, respectively) and the influence of the carboxyl groups is less pronounced. These results have implications for the design of new light-responsive CO-releasing molecules ("photoCORMs") intended for future medical use.
| Original language | English |
|---|---|
| Pages (from-to) | 5941-5952 |
| Number of pages | 12 |
| Journal | Inorganic Chemistry |
| Volume | 56 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 15 May 2017 |
Cite this
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Studies of carbon monoxide release from ruthenium(II) bipyridine carbonyl complexes upon UV-light exposure. / Kubeil, Manja; Vernooij, Robbin R; Kubeil, Clemens; Wood, Bayden R; Graham, Bim; Stephan, Holger; Spiccia, Leone.
In: Inorganic Chemistry, Vol. 56, No. 10, 15.05.2017, p. 5941-5952.Research output: Contribution to journal › Article › Research › peer-review
TY - JOUR
T1 - Studies of carbon monoxide release from ruthenium(II) bipyridine carbonyl complexes upon UV-light exposure
AU - Kubeil, Manja
AU - Vernooij, Robbin R
AU - Kubeil, Clemens
AU - Wood, Bayden R
AU - Graham, Bim
AU - Stephan, Holger
AU - Spiccia, Leone
PY - 2017/5/15
Y1 - 2017/5/15
N2 - The UV-light-induced CO release characteristics of a series of ruthenium(II) carbonyl complexes of the form trans-Cl[RuLCl2(CO)2] (L = 4,4′-dimethyl-2,2′-bipyridine, 4′-methyl-2,2′-bipyridine-4-carboxylic acid, or 2,2′-bipyridine-4,4′-dicarboxylic acid) have been elucidated using a combination of UV-vis absorbance and Fourier transform infrared spectroscopies, multivariate curve resolution alternating least-squares analysis, and density functional theory calculations. In acetonitrile, photolysis appears to proceed via a serial three-step mechanism involving the sequential formation of [RuL(CO)(CH3CN)Cl2], [RuL(CH3CN)2Cl2], and [RuL(CH3CN)3Cl]+. Release of the first CO molecule occurs quickly (k1 ≫ 3 min-1), while release of the second CO molecule proceeds at a much more modest rate (k2 = 0.099-0.17 min-1) and is slowed by the presence of electron-withdrawing carboxyl substituents on the bipyridine ligand. In aqueous media (1% dimethyl sulfoxide in H2O), the two photodecarbonylation steps proceed much more slowly (k1 = 0.46-1.3 min-1 and k2 = 0.026-0.035 min-1, respectively) and the influence of the carboxyl groups is less pronounced. These results have implications for the design of new light-responsive CO-releasing molecules ("photoCORMs") intended for future medical use.
AB - The UV-light-induced CO release characteristics of a series of ruthenium(II) carbonyl complexes of the form trans-Cl[RuLCl2(CO)2] (L = 4,4′-dimethyl-2,2′-bipyridine, 4′-methyl-2,2′-bipyridine-4-carboxylic acid, or 2,2′-bipyridine-4,4′-dicarboxylic acid) have been elucidated using a combination of UV-vis absorbance and Fourier transform infrared spectroscopies, multivariate curve resolution alternating least-squares analysis, and density functional theory calculations. In acetonitrile, photolysis appears to proceed via a serial three-step mechanism involving the sequential formation of [RuL(CO)(CH3CN)Cl2], [RuL(CH3CN)2Cl2], and [RuL(CH3CN)3Cl]+. Release of the first CO molecule occurs quickly (k1 ≫ 3 min-1), while release of the second CO molecule proceeds at a much more modest rate (k2 = 0.099-0.17 min-1) and is slowed by the presence of electron-withdrawing carboxyl substituents on the bipyridine ligand. In aqueous media (1% dimethyl sulfoxide in H2O), the two photodecarbonylation steps proceed much more slowly (k1 = 0.46-1.3 min-1 and k2 = 0.026-0.035 min-1, respectively) and the influence of the carboxyl groups is less pronounced. These results have implications for the design of new light-responsive CO-releasing molecules ("photoCORMs") intended for future medical use.
UR - http://www.scopus.com/inward/record.url?scp=85019487542&partnerID=8YFLogxK
U2 - 10.1021/acs.inorgchem.7b00599
DO - 10.1021/acs.inorgchem.7b00599
M3 - Article
VL - 56
SP - 5941
EP - 5952
JO - Inorganic Chemistry
JF - Inorganic Chemistry
SN - 0020-1669
IS - 10
ER -