Organized surface functional groups: cooperative catalysis via thiol/sulfonic acid pairing.
The synthesis and characterization of heterogeneous catalysts containing surfaces functionalized with discrete pairs of sulfonic acid and thiol groups are reported. A catalyst having acid and thiol groups separated by three carbon atoms is ca. 3 times more active than a material containing randomly distributed acid and thiol groups in the condensation of acetone and phenol to bisphenol A and 14 times more active in the condensation of cyclohexanone and phenol to bisphenol Z. Increasing the acid/thiol distance in the paired materials decreases both the activity and selectivity. This work clearly reveals the importance of nanoscale organization of two disparate functional groups on the surface of heterogeneous catalysts.
Margelefsky
Eric L
EL
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
Zeidan
Ryan K
RK
Dufaud
Véronique
V
Davis
Mark E
ME
D002384:Catalysis; D007659:Ketones / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D015394:Molecular Structure; D010636:Phenols / Q000138:chemical synthesis* / Q000737:chemistry; D012821:Silanes / Q000138:chemical synthesis / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*; D013451:Sulfonic Acids / Q000737:chemistry*; D013499:Surface Properties; D013997:Time Factors
D007659:Ketones; D010636:Phenols; D012821:Silanes; D013438:Sulfhydryl Compounds; D013451:Sulfonic Acids