Probing into the electrochemistry of four nickel(II) and cobalt(II) complexes with azadiphosphine ligands (PNP) and their catalysis on proton reduction

Xiao, Zhiyin; Natarajan, Mookan; Zhong, Wei; Liu, Xiaoming

doi:10.1016/j.electacta.2020.135998

Cited by 16 publications

(11 citation statements)

References 39 publications

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“…[35,36,42] UV-vis spectra were routinely measured with an Evolution 201 spectrometer (Thermo Fisher Scientific). [36,43] NMR spectra were collected on a Varian 400MR (Agilent). [36,43] Elemental analyses were measured on Elementar Vario EL III.…”

Section: Chemicals and Instrumentsmentioning

confidence: 99%

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Four iron(II) carbonyl complexes containing both pyridyl and halide ligands: Their synthesis, characterization, stability, and anticancer activity

Guo

Jin

Xiao

et al. 2020

Applied Organom Chemis

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Four iron(II) carbonyl complexes, fac-[Fe (CO) 3 X 2 (py)] (X = I − , 1 and Br − , 3), fac-[{Fe (CO) 3 X 2 } 2 (bipy)] (X = I − , 2 and Br − , 4), were facilely synthesized by reacting cis-[Fe (CO) 4 X 2 ] (X = I − , Br −) with pyridine (py) and 4,4 0-dipyridine (bipy) ligands, respectively, in good yields (70%85%). These complexes were fully characterized, and the structures of Complexes 2 and 3 were crystallographically analyzed. In dimethyl sulfoxide, they decomposed rapidly to release carbon monoxide (CO), and in methanol, they showed better stability which allowed kinetically analyzing their decomposing behaviors. The selfdecomposing in methanol fitted first-order kinetics with a half-time ranging from several minutes to 1 h. Our results suggested that the ligand with great conjugation (bipy) and strong electron-donating capability (iodide) could stabilize the iron(II) carbonyl complexes. The decomposition of the iodo complexes (1 and 2) involved the production of iodine radicals. MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assessments revealed that the efficacy against human bladder carcinoma cell line (RT112) is in the following trend: 1 > 2 > 3 > 4. The relatively strong efficacy of Complexes 1 and 2 is mainly contributed to the in situ generated iodine radicals. The combination of the cytotoxicity of the in situ generated radicals with the anticancer activity of CO as reported in literatures may lead to developing novel anticancer drugs with enhanced efficacy. K E Y W O R D S anticancer activity, carbon monoxide release and kinetics, iodine radical, iron carbonyl compounds, solvolysis Zhuming Guo and Jing Jin contributed equally to this work.

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Section: Chemicals and Instrumentsmentioning

confidence: 99%

“…[36,43] NMR spectra were collected on a Varian 400MR (Agilent). [36,43] Elemental analyses were measured on Elementar Vario EL III.…”

Section: Chemicals and Instrumentsmentioning

confidence: 99%

Four iron(II) carbonyl complexes containing both pyridyl and halide ligands: Their synthesis, characterization, stability, and anticancer activity

Guo

Jin

Xiao

et al. 2020

Applied Organom Chemis

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“…The addition of an electron to [Co(k 3 -2,6-{Ph 2 PNH} 2 NC 5 H 3 )Br] A leads to the proposed d 9 anion, [Co(k 3 -2,6-{Ph 2 PNH} 2 NC 5 H 3 )Br] À (A À ) depicted in Figure 4. On the basis of the optimized structure of [Co(k 3 -2,6-{Ph 2 PNH} 2 NC 5 H 3 )Br] A, the added electron would be placed in the LUMO, a σ* orbital, to yield a triplet anion.…”

Section: Electrochemical Characterizationmentioning

confidence: 99%

“…Numerous ligand frameworks have been explored with various first-row transition metal centers. [4][5][6][7][8][9][10] Tri-or tetradentate ligands can improve the overall stability of the complexes by compensating for the weakened metal-ligand coordination present in first-row transition metals, relative to the heavier congeners. [11,12] Pincer ligands are a particular class of rigid, planar, tridentate ligands that are known to modulate the electronic structure of first-row transition metal complexes to form effective proton reduction electrocatalysts.…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, molecular complexes for hydrogen generation are attractive due to the ability to modify supporting ligands and more directly probe mechanisms. Numerous ligand frameworks have been explored with various first‐row transition metal centers [4–10] . Tri‐ or tetradentate ligands can improve the overall stability of the complexes by compensating for the weakened metal‐ligand coordination present in first‐row transition metals, relative to the heavier congeners [11,12] .…”

Section: Introductionmentioning

confidence: 99%

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Elucidating Two Distinct Pathways for Electrocatalytic Hydrogen Production Using Co^II Pincer Complexes

2022

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Hydrogen gas is a sustainable energy source with water as the sole combustion product. As a result, efforts to catalyze H2 production are pertinent and widespread. The electrocatalytic H2 generating capabilities of two CoII complexes, [Co(κ3‐2,6‐{Ph2PNR}2(NC5H3))Br2] with R=H (I) or R=Me (II), were presented for a variety of proton sources including trifluoroacetic acid (TFA), acetic acid (AA), and trifluoroethanol (TFE). Cyclic voltammetry and controlled potential coulometry demonstrated that electrocatalysis from I and II occurred at two different potentials and are associated with different reduction processes. Density functional theory analysis provided insight into the identities of the catalyst and supported two distinct reaction pathways for electrocatalytic proton reduction. Specifically, stronger acids (e. g., AA, TFA) proceeded at −1.31 to −1.45 V through a MI/MIII pathway while sources with higher pKa values (e. g., TFE, H2O) generated hydrogen at −2.4 V via M0/MII ligand‐assisted metal‐centered reduction.

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The Discrete Breast Cancer Stem Cell Mammosphere Activity of Group 10‐Bis(azadiphosphine) Metal Complexes

et al. 2021

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We report the anti‐breast cancer stem cell (CSC) properties of a series of Group 10‐bis(azadiphosphine) complexes 1–3 under exclusively three‐dimensional cell culture conditions. The breast CSC mammosphere potency of 1–3 is dependent on the Group 10 metal present, increasing in the following order: 1 (nickel complex) <2 (palladium complex) <3 (platinum complex). Notably, 3 reduces the formation and size of mammospheres to a greater extent than salinomycin, an established CSC‐active compound, or any reported anti‐CSC metal complex tested under similar conditions. Mechanistic studies suggest that the most effective complexes 2 and 3 readily penetrate CSC mammospheres, enter CSC nuclei, induce genomic DNA damage, and trigger caspase‐dependent apoptosis. To the best of our knowledge, this is the first study to systematically probe the anti‐CSC activity of a series of structurally related Group 10 complexes and to be conducted entirely using three‐dimensional CSC culture conditions.

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Probing into the electrochemistry of four nickel(II) and cobalt(II) complexes with azadiphosphine ligands (PNP) and their catalysis on proton reduction

Cited by 16 publications

References 39 publications

Four iron(II) carbonyl complexes containing both pyridyl and halide ligands: Their synthesis, characterization, stability, and anticancer activity

Four iron(II) carbonyl complexes containing both pyridyl and halide ligands: Their synthesis, characterization, stability, and anticancer activity

Elucidating Two Distinct Pathways for Electrocatalytic Hydrogen Production Using Co^II Pincer Complexes

The Discrete Breast Cancer Stem Cell Mammosphere Activity of Group 10‐Bis(azadiphosphine) Metal Complexes

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Probing into the electrochemistry of four nickel(II) and cobalt(II) complexes with azadiphosphine ligands (PNP) and their catalysis on proton reduction

Cited by 16 publications

References 39 publications

Four iron(II) carbonyl complexes containing both pyridyl and halide ligands: Their synthesis, characterization, stability, and anticancer activity

Four iron(II) carbonyl complexes containing both pyridyl and halide ligands: Their synthesis, characterization, stability, and anticancer activity

Elucidating Two Distinct Pathways for Electrocatalytic Hydrogen Production Using CoII Pincer Complexes

The Discrete Breast Cancer Stem Cell Mammosphere Activity of Group 10‐Bis(azadiphosphine) Metal Complexes

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Elucidating Two Distinct Pathways for Electrocatalytic Hydrogen Production Using Co^II Pincer Complexes