Chemistry - A European Journal

Give and take both: A bis(benzimidazolate)-capped biomimetic [2Fe-2S] cluster has been characterized in different protonation states, both in the diferric and mixed-valent forms. Protonation does not lead to structural changes of the [2Fe-2S] core, but facilitates its reduction and causes pronounced valence localization in the mixed-valent state. Concerted proton and electron transfer back to the diferric cluster emulates a key step in the function of mitochondrial Rieske proteins (see scheme).

These things are sent to tri us: The introduction of CF₃ units into organic molecules is important and requires the development of convenient trifluoromethylating reagents. Here, PhI⁺CF₃, an acyclic electrophilic “CF₃⁺” species, is described, including its in situ generation from TMSCF₃, PhI(OAc)₂, and KF and its direct applications in sp² CH trifluoromethylations under mild transition-metal-free conditions (see scheme).

Capitalizing on cobalt: A new route to silyl enol ethers employing a Co-catalyzed cascade reaction featuring a tandem hydrosilation/hydrogen-transfer reaction is reported. The low catalyst loading, mild reaction conditions, and unique η²-silane resting state showcase the impressive utility of this seldom used transition-metal catalyst in CH activation reactions (see scheme).

The bright side of triple double bonds: Two series of stable tridentate cyclometalated Pt^II and Au^III allenylidene complexes were found to exhibit many functionalities, such as long-lived excited states, self-assembling into supramolecular nanostructures, DNA and nucleus binding and cellular imaging capabilities (see figure).

Grow slow: The usual direct treatment of MeLi and CuSPh did not yield X-ray quality crystals of MeCu(SPh)Li. An indirect method starting from Me₂CuLi⋅LiSPh and chalcone afforded the desired crystals by the slow reaction of the intermediate π-complex (see scheme). This strategy produced the first X-ray crystal structure of a Posner cuprate. A complementary NMR study showed that the contact ion pair was also the main species in solution.