title: The mechanical bond on carbon nanotubes: diameter-selective functionalization and effects on physical properties.
abstract: We describe the functionalization of SWNTs enriched in (6,5) chirality with electron donating macrocycles to yield rotaxane-type mechanically interlocked carbon nanotubes (MINTs). Investigations by means of electron microscopy and control experiments corroborated the interlocked nature of the MINTs. A comprehensive characterization of the MINTs through UV-vis-NIR, Raman, fluorescence, transient absorption spectroscopy, cyclic voltammetry, and chronoamperometry was carried out. Analyses of the spectroscopic data reveal that the MINT-forming reaction proceeds with diameter selectivity, favoring functionalization of (6,5) SWNTs rather than larger (7,6) SWNTs. In the ground state, we found a lack of significant charge-transfer interactions between the electron donor exTTF and the SWNTs. Upon photoexcitation, efficient charge-transfer between the electron donating exTTF macrocycles and SWNTs was demonstrated. As a complement, we established significantly different charge-transfer rate constants and diffusion coefficients for MINTs and the supramolecular models, which confirms the fundamentally different type of interactions between exTTF and SWNTs in the presence or absence of the mechanical bond. Molecular mechanics and DFT calculations support the experimental findings.
authors.affiliation: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente, 7, 28049 Madrid, Spain. encarnacion.lorenzo@uam.es.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Martínez-Periñán
authors.affiliation: IMDEA Nanoscience, C/Faraday 9, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain. emilio.perez@imdea.org.
authors.forename: Alberto
authors.initials: A
authors.lastname: de Juan
authors.affiliation: Centro Joxe Mari Korta, Avenida de Tolosa, 72, 20018 Donostia-San Sebastian, Spain. angel.rubio@ehu.es.
authors.forename: Yann
authors.initials: Y
authors.lastname: Pouillon
authors.affiliation: Friedrich-Alexander-Universität Erlangen/Nürnberg, Department Chemie und Pharmazie, Lehrstuhl für Physikalische Chemie I, Egerlandstraße 3, 91058 Erlangen, Germany. dirk.guldi@fau.de.
authors.forename: Christoph
authors.initials: C
authors.lastname: Schierl
authors.affiliation: Friedrich-Alexander-Universität Erlangen/Nürnberg, Department Chemie und Pharmazie, Lehrstuhl für Physikalische Chemie I, Egerlandstraße 3, 91058 Erlangen, Germany. dirk.guldi@fau.de.
authors.forename: Volker
authors.initials: V
authors.lastname: Strauss
authors.affiliation: IMDEA Nanoscience, C/Faraday 9, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain. emilio.perez@imdea.org and Departamento de Química Orgánica, Facultad de CC Químicas, Universidad Complutense de Madrid, 28040 Madrid, Spain.
authors.forename: Nazario
authors.initials: N
authors.lastname: Martín
authors.affiliation: Centro Joxe Mari Korta, Avenida de Tolosa, 72, 20018 Donostia-San Sebastian, Spain. angel.rubio@ehu.es.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Rubio
authors.affiliation: Friedrich-Alexander-Universität Erlangen/Nürnberg, Department Chemie und Pharmazie, Lehrstuhl für Physikalische Chemie I, Egerlandstraße 3, 91058 Erlangen, Germany. dirk.guldi@fau.de.
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.affiliation: Departamento de Química Analítica y Análisis Instrumental, Facultad de Ciencias, Universidad Autónoma de Madrid, C/Francisco Tomás y Valiente, 7, 28049 Madrid, Spain. encarnacion.lorenzo@uam.es and IMDEA Nanoscience, C/Faraday 9, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain. emilio.perez@imdea.org.
authors.forename: Encarnación
authors.initials: E
authors.lastname: Lorenzo
authors.affiliation: IMDEA Nanoscience, C/Faraday 9, Ciudad Universitaria de Cantoblanco, 28049 Madrid, Spain. emilio.perez@imdea.org.
authors.forename: Emilio M
authors.initials: EM
authors.lastname: Pérez