Direct Estimation of the Surface Location of Immobilized Functional Groups for Concerted Catalysis Using a Probe Molecule

• Published in: Chemistry : a European journal Vol. 22; no. 15; pp. 5113 - 5117
• Main Authors: Noda, Hiroto, Motokura, Ken, Wakabayashi, Yusuke, Sasaki, Kaori, Tajiri, Hiroo, Miyaji, Akimitsu, Yamaguchi, Sho, Baba, Toshihide
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 04.04.2016; Wiley Subscription Services, Inc
• Subjects: active site distance; amine; Amines; Catalysis; Catalysts; Catalytic activity; Chemistry; Coordination compounds; Diamines; Functional anatomy; Functional groups; heterogeneous concerted catalysis; Ligands; Metals; NMR; Nuclear magnetic resonance; probe molecule; Proximity; Silicon dioxide; Surface chemistry; active site distance; heterogeneous concerted catalysis; amine; probe molecule
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201600263

The location of active sites during concerted catalysis by a metal complex and tertiary amine on a SiO2 surface is discussed based on the interaction between the functionalized SiO2 surface and a probe molecule, p‐formyl phenylboronic acid. The interactions of the probe molecule with the surface functionalities, diamine ligand, and tertiary amine, were analyzed by FT‐IR and solid‐state 13C and 11B MAS NMR. For the catalyst exhibiting high 1,4‐addition activity, the diamine ligand and tertiary amine base exist in closer proximity than in the catalyst with low activity. Probing the surface: A novel technique using a probe molecule enables the measurement of active site distance for surface concerted catalysis; the relationship between catalytic activity and the immobilized metal complex–organic base distance on the SiO2 surface was clarified.