Structural, spectroscopic and theoretical studies of a diruthenium(II,II) tetraformamidinate that reversibly binds dioxygen Dedicated

Sam Ring, Anthony J H M Meijer, Nathan J. Patmore

Research output: Contribution to journalArticle

4 Citations (Scopus)


The reaction of Ru2(O2CMe)4 with N,N′-bis(3,5-dimethoxyphenyl)formamidine (Hdmof) in refluxing toluene solutions yields Ru2(dmof)4 as a diamagnetic red solid that is extremely air-sensitive. The crystal structure reveals the expected paddlewheel arrangement of ligands around the Ru24+ core, with a relatively long Ru-Ru bond (2.4999(8) Å) that is consistent with a σ2π4δ2π4 electronic configuration. This is supported DFT calculations that show this electronic structure results from destabilization of the δ orbital due to antibonding interactions with the formamidinate ligands. The cyclic voltammogram of Ru2(dmof)4 in a 0.1 M nBu4NPF6/CH2Cl2 solution shows two redox processes, assigned as successive oxidations corresponding to the Ru24+/5+ and Ru25+/6 redox couples. Changes in the electronic absorption spectra associated with these oxidation processes were probed using a UV-Vis spectroelectrochemical study. Ru2(dmof)4 reacts with dioxygen in solution to generate a purple compound that decomposes within an hour at room temperature. Bubbling N2 gas through the purple solution regenerates Ru2(dmof)4, as evidenced by UV-Vis spectrometry and cyclic voltammetry, suggesting that the dioxygen reversibly binds to the diruthenium core.

Original languageEnglish
Pages (from-to)87-93
Number of pages7
Early online date30 Sep 2015
Publication statusPublished - 8 Jan 2016


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