Several nitrosyl complexes of Fe and Co have been prepared using the sterically hindered Ar-nacnac ligand (Ar-nacnac = anion of [(2,6-diisopropylphenyl)NC(Me)]2CH). The dinitrosyl iron complexes, [Fe(NO)2(Ar-nacnac)] (1) and (Bu4N)[Fe(NO)2(Ar-nacnac)] (2) react with [FeIII(TPP)Cl] (TPP = tetraphenylporphine dianion) to generate [FeII(TPP)(NO)] and the corresponding mononitrosyl iron complexes. The factors governing NO-transfer with DNICs 1 and 2 are evaluated, together with the chemistry of the related mononitrosyl iron complex, [Fe(NO)Br(Ar-nacnac)], 4. The synthesis and properties of the related cobalt dinitrosyl [Co(NO)2(Ar-nacnac)], 3, is also discussed for comparison to DNICs 1 and 2. The solid-state structures of several of these compounds as determined by X-ray crystallography are reported.

Addition of H+ to a synthetic (µ-1,2-peroxo)diiron(III) model complex results in protonation of a carboxylate rather than the peroxo ligand. This conclusion is based on spectroscopic evidence from UV-vis, 57Fe Mössbauer, resonance Raman, infrared, and 1H/19F NMR studies. These results suggest a similar role for protons in the dioxygen activation reactions in soluble methane monooxygenase and related carboxylate-bridged diiron enzymes.

Although reactive aldehyde species (RASP) are associated with the pathogenesis of many major diseases, there are currently no clinically approved treatments for RASP overload. Conventional aldehyde detox agents are stoichiometric reactants that get consumed upon reacting with their biological targets, which limits their therapeutic efficiency. To achieve longer‐lasting detoxification effects, small‐molecule intracellular metal catalysts (SIMCats) were used to protect cells by converting RASP into non‐toxic alcohols. It was shown that SIMCats were significantly more effective in lowering cell death from the treatment with 4‐hydroxynon‐2‐enal than aldehyde scavengers over a 72 h period. Studies revealed that SIMCats reduced the aldehyde accumulation in cells exposed to the known RASP inducer arsenic trioxide. This work demonstrates that SIMCats offer unique benefits over stochiometric agents, potentially providing new ways to combat diseases with greater selectivity and efficiency than existing approaches.

Studies of organometallic reactions in living cells commonly rely on ensemble-averaged measurements, which can obscure the detection of reaction dynamics or location-specific behavior. This information is necessary to guide the design of bioorthogonal catalysts with improved biocompatibility, activity, and selectivity. By leveraging the high spatial and temporal resolution of single-molecule fluorescence microscopy, we have successfully captured single-molecule events promoted by Ru complexes inside live A549 human lung cells. By observing individual allylcarbamate cleavage reactions in real-time, our results revealed that they occur with greater frequency inside the mitochondria than in the non-mitochondria regions. The estimated turnover frequency of the Ru complexes was at least 3fold higher in the former than the latter. These results suggest that organelle specificity is a critical factor to consider in intracellular catalyst design, such as in developing metallodrugs for therapeutic applications.

Studies of organometallic reactions in living cells commonly rely on ensemble‐averaged measurements, which can obscure the detection of reaction dynamics or location‐specific behavior. This information is necessary to guide the design of bioorthogonal catalysts with improved biocompatibility, activity, and selectivity. By leveraging the high spatial and temporal resolution of single‐molecule fluorescence microscopy, we have successfully captured single‐molecule events promoted by Ru complexes inside live A549 human lung cells. By observing individual allylcarbamate cleavage reactions in real‐time, our results revealed that they occur with greater frequency inside the mitochondria than in the non‐mitochondria regions. The estimated turnover frequency of the Ru complexes was at least 3‐fold higher in the former than the latter. These results suggest that organelle specificity is a critical factor to consider in intracellular catalyst design, such as in developing metallodrugs for therapeutic applications.