Efficient Synthesis of Calix[4]phyrins Catalyzed by Amberlyst™-15 and Its Noncovalent Interactions with Neutral Molecules

Title:Efficient Synthesis of Calix[4]phyrins Catalyzed by Amberlyst™-15 and Its Noncovalent Interactions with Neutral Molecules

Volume: 21 Issue: 26

Author(s): Anchal Singhal*Shive M.S. Chauhan*

Affiliation:

• Department of Chemistry, University of Delhi, Delhi 110 007,India

• Department of Chemistry, University of Delhi, Delhi 110 007,India

Keywords: Acetone, dipyrromethane, amberlyst™-15, calix[4]phyrin, calix[6]phyrin non-covalent interactions, absorption studies.

Abstract: Background: Calix[4]phyrins are fascinating hybrid molecules that contain a mixture of sp2- and sp3- hybridized meso-carbon bridges and bear analogy to both porphyrins and calix[4]pyrroles and hence find use in various applications. Various methods have been reported in the literature for the synthesis of calix [4] phyrins but with disadvantages of using corrosive acids and getting mixture of products, the separation of which is tedious. Hence, mild synthetic route for synthesis of calix[4]phyrins is highly desirable.

Objective: Mild and efficient synthesis of calix[4]phyrins and their binding studies with neutral molecules are presented in this manuscript.

Methods: Various functional calix[4]phyrins were synthesized by the condensation reaction of acetone with various functional dipyrromethanes catalyzed by reusable heterogeneous Amberlyst™-15 at ambient temperature followed by oxidation with DDQ. Different solvents were used as reaction medium to optimize the yield of calix[4]phyrins. Non-covalent interactions of 5,15-di-(p-methoxyphenyl)-10,10,20,20-tetramethylcalix[4] phyrin with p-nitrophenol and p-nitrotoluene were studied using UV-Vis spectrophotometer.

Results: Amberlyst™-15 acts as an efficient catalyst for the synthesis of calix[4]phyrins in moderate to good yields. Dichloromethane was found to be best suitable solvent for the synthesis of calix[4]phyrins. In the UVVis studies of 5,15-di-(p-methoxyphenyl)-10,10,20,20-tetramethylcalix[4]phyrin with p-nitrophenol as well as with p-nitrotoluene, two clear isobestic points were observed in each spectra showing that two molecules are interacting with each other.

Conclusion: An efficient method is developed to synthesize a parallel library of calix[4]phyrins. Non-covalent interactions between 5,15-di-(p-methoxyphenyl)-10,10,20,20-tetramethylcalix[4]phyrin as neutral donor and aromatic nitro compounds as neutral acceptors are established by UV-Vis studies.

Cite this article as:

Singhal Anchal*, Chauhan M.S. Shive *, Efficient Synthesis of Calix[4]phyrins Catalyzed by Amberlyst™-15 and Its Noncovalent Interactions with Neutral Molecules, Current Organic Chemistry 2017; 21 (26) . https://dx.doi.org/10.2174/1385272821666170417165046