Simpler and Cleaner Synthesis of Variously Capped Cobalt Nanocrystals Applied in the Semihydrogenation of Alkynes

Abstract

Unlike the classical organometallic approach, we report here a synthetic pathway requiring no reducing sources or heating to produce homogenous hexagonal close packed cobalt nanocrystals (NCs). Involving a disproportionation process, this simple and fast (6 min) synthesis is performed at room temperature in presence of eco-friendly fatty alcohols to passivate Co NCs. Through a recycling step, the yield of Co NCs is improved and the waste generation is limited making this synthetic route cleaner. After an easy exchange of the capping ligands, we applied them as unsupported catalyst in the stereo-selective semi-hydrogenation of alkynes. ASSOCIATED CONTENT Supporting InformationExperimental procedures, microscopic analyses (TEM, SEM-EDX), size histograms, characterization of products resulting from alkynes catalysis and magnetic measurement information. The Supporting Information is available free of charge on the ACS Publications website.

Versatile Interfacial Self-Assembly of Ti3C2Tx MXene Based Composites with Enhanced Kinetics for Superior Lithium and Sodium Storage

“…In order to further confirm the bind between OA molecules and Co-NiS, fresh Fe 3 O 4 and MnO 2 nanoparticles were modified with OA (see Methods section for details) and the corresponding Fourier transform infrared (FTIR) spectra are shown in Figure D. The double absorption peaks between 3400 and 3500 cm –1 emerge in the FTIR spectra of both OA-modified Fe 3 O 4 and MnO 2 , which could be attributed to symmetrical and asymmetrical stretching vibration of -NH 2 , − verifying the bind between OA molecules and Co-NiS. Subsequently, the colloidal Co-NiS nanorod cyclohexane dispersion was added into the aqueous MXene colloidal dispersion.…”

The five shades of oleylamine in a morphological transition of cobalt nanospheres to nanorods

“…48 Previously we showed that our unsupported Co NPs were able to catalyze the reduction of alkyne to alkene in presence of hydrogen. 49 Thus, we designed a specific setup in an H-tube, formed by a glass link between two microwaves vials, and spherical Co NPs in OAm at 190°C were introduced on one side and spherical Co NPs with diphenylacetylene (DPA) were mixed in toluene on the other side at RT (Scheme 2).…”

“…It was established that similar spherical cobalt NPs can be obtained with bromine and iodine complex derivatives using the same redox pathway. 25,49 In literature, it is also mentioned that bromine 55,56 and on rare occasions iodine 57 were able to induce oxidative etching allowing the production of Co NRs through a similar mechanism. [CoBr(PPh3)3] and [CoI(PPh3)3] were synthesized and Co NRs were obtained after 10h and 18h, respectively (Fig.…”

Stereoselective Semi‐Hydrogenations of Alkynes by First‐Row (3d) Transition Metal Catalysts

“…A recent study by the group of Petit [72] used the commercial Co(I) precursor [CoCl(PPh 3 ) 3 ] to generate cobalt nanoparticles via disproportionation in THF. Rapid agglomeration and subsequent deactivation of the catalyst was inhibited by the addition of fatty alcohols.…”

“… The hypothesized catalytic cycles involved in the photochemical transfer semi‐hydrogenation of alkynes. [72] …”