A new paper from Patricia Lara has been published in Nanoscale journal.
“Platinum nanoparticles stabilized by N-heterocyclic thiones. Synthesis and catalytic activity in mono- and di-hydroboration of alkynes”
This published work is the result of Leonardo Moraes’ PhD thesis in collaboration with the groups of Salvador Conejero and Javier Rojo.
You can read it at Nanoscale, 2020, 12, 6821
Congratulations Patricia! 🙂
Abstract: N-Heterocyclic Thiones (NHT) proved to be efficient ligands for the stabilization of small platinum nano- particles (1.3–1.7 nm), synthesized by decomposition of [Pt(dba)2], under a H2 atmosphere, in the presence of variable sub-stoichiometric amounts of the NHT. Full characterization by means of TEM, HR-TEM, NMR, ICP, TGA and XPS have been carried out, providing information about the nature of the metal nanoparticles and the interaction of the NHT ligands to the metal surface. Importantly, DFT calculations indicate that some NHT ligands interact with the metal through the CvC double bond of the imidazole fragment in addition to the sulfur atom, thus providing additional stabilization to the nanoparticles. According to XPS, TGA and ICP techniques, the surface coverage by the ligand increases by decreasing the size of the substi- tuents on the nitrogen atom. The platinum nanoparticles have been used as catalyst in the hydroboration of alkynes. The most active system is that with a less covered surface area lacking an interaction of the ligand by means of the CvC double bond. This catalyst hydroborates alkynes with excellent selectivities towards the monoborylated anti-Markovnikov product (vinyl-boronate) when one equiv. of borane is used. Very interestingly, aliphatic alkynes undergo a second hydroborylation process leading to the corres- ponding 1,1- and 1,2-diboroylated species with good selectivities towards the former.
Authors: Leonardo C. Moraes, Rute C. Figueiredo, Juan P. Espinós, Florencia Vattier, Antonio Franconetti, Carlos Jaime, Bertrand Lacroix, Javier Rojo, Patricia Lara and Salvador Conejero.