A Well-Defined Pd Hybrid Material for the Z-Selective Semihydrogenation of Alkynes Characterized at the Molecular Level by DNP SENS

• Published in: Chemistry : a European journal Vol. 19; no. 37; pp. 12234 - 12238
• Main Authors: Conley, Matthew P., Drost, Ruben M., Baffert, Mathieu, Gajan, David, Elsevier, Cornelis, Franks, W. Trent, Oschkinat, Hartmut, Veyre, Laurent, Zagdoun, Alexandre, Rossini, Aaron, Lelli, Moreno, Lesage, Anne, Casano, Gilles, Ouari, Olivier, Tordo, Paul, Emsley, Lyndon, Copéret, Christophe, Thieuleux, Chloé
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 09.09.2013; WILEY‐VCH Verlag; Wiley Subscription Services, Inc; Wiley-VCH Verlag
• Subjects: Alkenes - chemistry; Alkynes; Alkynes - chemistry; Analytical chemistry; Bonding; Carbenes; Chemical Sciences; Chemistry; Displays; hybrid materials; Hydrogenation; Magnetic Resonance Spectroscopy; Materials selection; Methane - analogs & derivatives; Methane - chemistry; Molecular Conformation; NMR spectroscopy; or physical chemistry; Palladium; Palladium - chemistry; Polarization; semihydrogenation; Silicon Dioxide - chemistry; Theoretical and; carbenes; hybrid materials; palladium; NMR spectroscopy; semihydrogenation; SURFACE ORGANOMETALLIC CHEMISTRY; FORMIC-ACID; N-HETEROCYCLIC CARBENE; COMPLEX; ALKENE METATHESIS; NHC; DYNAMIC NUCLEAR-POLARIZATION; HYDROGENATION CATALYSTS; ENHANCED NMR-SPECTROSCOPY; HETEROGENEOUS CATALYSTS
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201302484

Direct evidence of the conformation of a Pd–N heterocyclic carbene (NHC) moiety imbedded in a hybrid material and of the Pd–NHC bond were obtained by dynamic nuclear polarization surface‐enhanced NMR spectroscopy (DNP SENS) at natural abundance in short experimental times (hours). Overall, this silica‐based hybrid material containing well‐defined Pd–NHC sites in a uniform environment displays high activity and selectivity in the semihydrogenation of alkynes into Z‐alkenes (see figure).