Catalytic activity of copper(II) benzenetricarboxylate (HKUST-1) in reactions of aromatic aldehydes condensation with nitromethane: Kinetic and diffusion study

• Sieving effect in catalysis of Henry reaction by HKUST-1 was found.
• Accessibility of pores to reagents was confirmed by sorption measurements.
• Rate of salicylaldehyde sorption is governed by the internal diffusion stage.
• Molecular mechanic modeling showed that pores are accessible to salicylaldehyde.
• Diffusion of reagents in pores has significant contribution to reaction rate.

Catalytic activity of copper(II) 1,3,5-benzenetricarboxylate, HKUST-1, in reactions of condensation of aromatic aldehydes with nitromethane was studied. It was shown that HKUST-1 catalyzed condensation of salicylaldehyde with nitromethane leading to formation of trans-nitrovinylphenol, while 9-anthracenecarbaldehyde did not react in the same conditions. Catalytic activity of HKUST-1 was consistent with its sorption capacity in respect to the reagents. The difference in catalytic activity of HKUST-1 in reactions with salicylaldehyde and 9-anthracenecarbaldehyde can be caused by sieving effect (molecules discrimination by size). Kinetics of salicylaldehyde condensation with nitromethane, catalyzed by HKUST-1, as well as kinetics of salicylaldehyde sorption by HKUST-1 were studied. Accessibility of pores of HKUST-1 to salicylaldehyde and condensation product (trans-nitrovinylphenol) was evaluated by molecular mechanics. Catalytic activity (reaction rate and salicylaldehyde diffusion rate) of HKUST-1 is compared with FeIII analog, role of diffusion rate is shown.

HKUST-1 catalyzed condensation of salicylaldehyde with nitromethane leading to formation of trans-nitrovinylphenol, while 9-anthracenecarbaldehyde did not react. Kinetics of salicylaldehyde condensation with nitromethane, as well as kinetics of salicylaldehyde sorption by HKUST-1 were studied. Accessibility of catalyst’s pores to salicylaldehyde and trans-nitrovinylphenol was evaluated by molecular mechanics.Figure optionsDownload as PowerPoint slide