| People | Locations | Statistics |
|---|---|---|
| Naji, M. |
| |
| Motta, Antonella |
| |
| Aletan, Dirar |
| |
| Mohamed, Tarek |
| |
| Ertürk, Emre |
| |
| Taccardi, Nicola |
| |
| Kononenko, Denys |
| |
| Petrov, R. H. | Madrid |
|
| Alshaaer, Mazen | Brussels |
|
| Bih, L. |
| |
| Casati, R. |
| |
| Muller, Hermance |
| |
| Kočí, Jan | Prague |
|
| Šuljagić, Marija |
| |
| Kalteremidou, Kalliopi-Artemi | Brussels |
|
| Azam, Siraj |
| |
| Ospanova, Alyiya |
| |
| Blanpain, Bart |
| |
| Ali, M. A. |
| |
| Popa, V. |
| |
| Rančić, M. |
| |
| Ollier, Nadège |
| |
| Azevedo, Nuno Monteiro |
| |
| Landes, Michael |
| |
| Rignanese, Gian-Marco |
|
Repo, Timo
University of Helsinki
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (15/15 displayed)
- 2024Mesoporous silica-amine beads from blast furnace slag for CO<sub>2</sub> capture applicationscitations
- 2023Functionalization of nitrogen-doped graphene quantum dotcitations
- 2022Parahydrogen-induced polarization study of imine hydrogenations mediated by a metal-free catalystcitations
- 2017Nuclear spin hyperpolarization with ansa-aminoboranes : a metal-free perspective for parahydrogen-induced polarizationcitations
- 2016Nuclear spin hyperpolarization with ansa-aminoboranescitations
- 2016Towards improved solubility of poorly water-soluble drugscitations
- 2014Tweezers for Parahydrogencitations
- 2011Two- and three-dimensional packing diagrams of M(salophen) complexescitations
- 2006Synthesis of titanium complexes bearing two mono anionic malonic acid ester based ligands and their use as catalyst precursors in ethene polymerizationcitations
- 2006High-molar-mass polypropene with tunable elastic properties by hafnocene/borate catalystscitations
- 2004Tetrakis Sn(IV) alkoxides as novel initiators for living ring-opening polymerization of lactidescitations
- 2002New bis(imino)pyridine-iron(II)- and cobalt(II)-based catalysts: synthesis characterization and activity towards polymerization of ethylenecitations
- 2002Copolymerization of propene with phenylnorbornene using ansa-bridged metallocene catalystscitations
- 2001Copolymerization of carbon monoxide with exo-methylenecycloalkane and dienes: synthesis of functionalized aliphatic polyketonescitations
- 2000Synthesis and crystal structure of [1-(eta(5)-9-fluorenyl)-2-(eta(5)-1-indenyl)ethane]-hafnium dimethyl
Places of action
| Organizations | Location | People |
|---|
article
Nuclear spin hyperpolarization with ansa-aminoboranes
Abstract
<p>The parahydrogen-induced polarization (PHIP) phenomenon, observed when parahydrogen is used in H-2 addition processes, provides a means for substantial NMR signal enhancements and mechanistic studies of chemical reactions. Commonly, noble metal complexes are used for parahydrogen activation, whereas metal-free activation is rare. Herein, we report a series of unimolecular metal-free frustrated Lewis pairs based on an ansa-aminoborane (AAB) moiety in the context of PHIP. These molecules, which have a "molecular tweezers'' structure, differ in their substituents at the boryl site (-H, -Ph, -o-iPr-Ph, and -Mes). PHIP effects were observed for all the AABs after exposing their solutions to parahydrogen in a wide temperature range, and experimental measurements of their kinetic and thermodynamic parameters were performed. A theoretical analysis of their nuclear spin polarization effects is presented, and the roles of chemical exchange, chemical equilibrium and spin dynamics are discussed in terms of the key dimensionless parameters. The analysis allowed us to formulate the prerequisites for achieving strong polarization effects with AAB molecules, which can be applied for further design of efficient metal-free tweezers-like molecules for PHIP. Mechanistic (chemical and physical) aspects of the observed effects are discussed in detail. In addition, we performed quantum chemical calculations, which confirmed that the J-coupling between the parahydrogen-originated protons in AAB-H-2 molecules is mediated through dihydrogen bonding.</p>