Curious Case of Cobaltocenium Carbaldehyde.
Daniel MeniaMichael PittracherHolger KopackaKlaus WurstFlorian R NeururerDaniel LeitnerStephan HohlochMaren PodewitzBenno BildsteinPublished in: Organometallics (2023)
Cobaltocenium carbaldehyde (formylcobaltocenium) hexafluoridophosphate, a long sought-after functionalized cobaltocenium salt, is accessible from cobaltocenium carboxylic acid by a three-step synthetic sequence involving (i) chlorination to the acid chloride, (ii) copper-borohydride reduction to the hydroxymethyl derivative, and (iii) Dess-Martin oxidation to the title compound. Due to the strongly electron-withdrawing cationic cobaltocenium moiety, no standard aldehyde reactivity is observed. Instead, nucleophilic addition followed by haloform-type cleavage prevails, thereby ruling out common useful aldehyde derivatization. One-electron reduction of cobaltocenium carbaldehyde hexafluoridophosphate affords the deep-blue, isolable cobaltocene carbaldehyde 19-valence-electron radical whose spin density is located fully at cobalt and not at the formyl carbon atom. 1 H/ 13 C NMR, IR, EPR spectroscopy, high-resolution mass spectrometry, cyclic voltammetry, single crystal structure analysis (XRD), and density functional theory are applied to characterize these unusual formyl-cobaltocenium/cobaltocene compounds.
Keyphrases
- density functional theory
- crystal structure
- high resolution mass spectrometry
- molecular dynamics
- liquid chromatography
- electron transfer
- ultra high performance liquid chromatography
- high resolution
- gas chromatography
- solar cells
- mass spectrometry
- solid state
- magnetic resonance
- single molecule
- tandem mass spectrometry
- electron microscopy
- ms ms
- quantum dots
- high performance liquid chromatography
- simultaneous determination
- liquid chromatography tandem mass spectrometry
- hydrogen peroxide
- room temperature
- dna binding
- carbon nanotubes
- water soluble
- transition metal