3 research outputs found
Magnetic Superbasic Proton Sponges Are Readily Removed and Permit Direct Product Isolation
Workup in organic synthesis can be
very time-consuming, particularly
when using reagents with both a solubility similar to that of the
desired products and a tendency not to crystallize. In this respect,
reactions involving organic bases would strongly benefit from a tremendously
simplified separation process. Therefore, we synthesized a derivative
of the superbasic proton sponge 1,8-bisÂ(dimethylamino)Ânaphthalene
(DMAN) and covalently linked it to the strongest currently available
nanomagnets based on carbon-coated cobalt metal nanoparticles. The
immobilized magnetic superbase reagent was tested in Knoevenagel-
and Claisen–Schmidt-type condensations and showed conversions
of up to 99%. High yields of up to 97% isolated product could be obtained
by simple recrystallization without using column chromatography. Recycling
the catalyst was simple and fast with an insignificant decrease in
catalytic activity
Selective Low-Energy Carbon Dioxide Adsorption Using Monodisperse Nitrogen-Rich Hollow Carbon Submicron Spheres
Monodisperse,
nitrogen-doped hollow carbon spheres of submicron
size were synthesized using hexamethoxymethylmelamine as both a carbon
and nitrogen source in a short (1 h) microwave-assisted synthesis.
After carbonization at 550 °C, porous carbon spheres with a remarkably
high nitrogen content of 37.1% were obtained, which consisting mainly
of highly basic pyridinic moieties. The synthesized hollow spheres
exhibited high selectivity for carbon dioxide (CO<sub>2</sub>) over
nitrogen and oxygen gases, with a capture capacity up to 1.56 mmol
CO<sub>2</sub> g<sup>–1</sup>. The low adsorption enthalpy
of the synthesized hollow carbon spheres permits good adsorbent regeneration.
Evaluation of the feasibility of scaling up shows their potential
for large-scale applications
Selective Low-Energy Carbon Dioxide Adsorption Using Monodisperse Nitrogen-Rich Hollow Carbon Submicron Spheres
Monodisperse,
nitrogen-doped hollow carbon spheres of submicron
size were synthesized using hexamethoxymethylmelamine as both a carbon
and nitrogen source in a short (1 h) microwave-assisted synthesis.
After carbonization at 550 °C, porous carbon spheres with a remarkably
high nitrogen content of 37.1% were obtained, which consisting mainly
of highly basic pyridinic moieties. The synthesized hollow spheres
exhibited high selectivity for carbon dioxide (CO<sub>2</sub>) over
nitrogen and oxygen gases, with a capture capacity up to 1.56 mmol
CO<sub>2</sub> g<sup>–1</sup>. The low adsorption enthalpy
of the synthesized hollow carbon spheres permits good adsorbent regeneration.
Evaluation of the feasibility of scaling up shows their potential
for large-scale applications