Triazine-Carbon Nanotubes: New Platforms for the Design of Flavin Receptors

• Published in: Chemistry : a European journal Vol. 22; no. 26; pp. 8879 - 8888
• Main Authors: Lucío, María Isabel, Pichler, Federica, Ramírez, José Ramón, de la Hoz, Antonio, Sánchez-Migallón, Ana, Hadad, Caroline, Quintana, Mildred, Giulani, Angela, Bracamonte, Maria Victoria, Fierro, Jose L. G., Tavagnacco, Claudio, Herrero, María Antonia, Prato, Maurizio, Vázquez, Ester
• Format: Journal Article
• Language: English
• Published: Germany Blackwell Publishing Ltd 20-06-2016; Wiley Subscription Services, Inc
• Subjects: Aromatic compounds; Bonding strength; Carbon; Carbon nanotubes; Catalysis; Catalysts; Chains; Chemistry; Derivatives; Design; Design analysis; donor-acceptor systems; Flavin; Fluorescence; Functional anatomy; Functional groups; Hybrids; Hydrogen; Hydrogen bonding; Hydrogen bonds; Irradiation; molecular recognition; Multi wall carbon nanotubes; Nanotechnology; Nanotubes; noncovalent interactions; Platforms; Receptors; Riboflavin; Single wall carbon nanotubes; Spectroscopic analysis; Stacking; Triazine; Vitamin B; Walls; nanotubes; molecular recognition; donor-acceptor systems; receptors; noncovalent interactions
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201600630

The synthesis of functionalised carbon nanotubes as receptors for riboflavin (RBF) is reported. Carbon nanotubes, both single‐walled and multi‐walled, have been functionalised with 1,3,5‐triazines and p‐tolyl chains by aryl radical addition under microwave irradiation and the derivatives have been fully characterised by using a range of techniques. The interactions between riboflavin and the hybrids were analysed by using fluorescence and UV/Vis spectroscopic techniques. The results show that the attached functional groups minimise the π‐π stacking interactions between riboflavin and the nanotube walls. Comparison of p‐tolyl groups with the triazine groups shows that the latter have stronger interactions with riboflavin because of the presence of hydrogen bonds. Moreover, the triazine derivatives follow the Stern–Volmer relationship and show a high association constant with riboflavin. In this way, artificial receptors in catalytic processes could be designed through specific control of the interaction between functionalised carbon nanotubes and riboflavin.
Receptors on rods: Artificial receptors of flavins are synthesised by the functionalisation of carbon nanotubes with 1,3,5‐triazines (see figure). The ability of the nanotubes to recognise riboflavin is analysed by different techniques and the results highlight the major role of hydrogen bonds in the process. The possibility of modifying flavins and carbon nanotubes paves the way for the design of specific receptors in catalytic processes.