title: Self-assembly and electrochemical oxidation of polyamidoamine-carbazole dendron surfmer complexes: nanoring formation.
abstract: We report a detailed and quantitative study on the supramolecular complexation of amine-functionalized polyamidoamine (PAMAM) dendrimer G(4)-NH(2) with carboxylic acid terminal dendrons containing peripheral electroactive carbazole groups of different generations (G(0)COOH, G(1)COOH, and G(2)COOH). While the focus is on a detailed understanding and mechanism of complex formation, subsequent electrochemical oxidation of the dendron surfmers resulted in the formation of nanoring structures electrodeposited on the conducting substrate. Complexation was confirmed by NMR, UV-vis, and IR measurements. Critical micelle concentration (CMC), atomic force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS) studies revealed that the ringlike structures were formed during the equilibrium-decomplexation stage and that the electrochemical process did not destroy the complex but rather stabilized it. The different generations of the dendrons provided various structures and complex formation efficacy. This type of template polymerization combined with electrochemically anodic oxidation has not been previously reported.
authors.affiliation: Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA.
authors.forename: Chatthai
authors.initials: C
authors.lastname: Kaewtong
authors.forename: Guoqian
authors.initials: G
authors.lastname: Jiang
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Felipe
authors.forename: Buncha
authors.initials: B
authors.lastname: Pulpoka
authors.forename: Rigoberto
authors.initials: R
authors.lastname: Advincula
mesh_terms: D002227:Carbazoles / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D050091:Dendrimers; D004595:Electroplating / Q000379:methods*; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010084:Oxidation-Reduction; D010316:Particle Size; D011073:Polyamines / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D002227:Carbazoles; D050091:Dendrimers; D046911:Macromolecular Substances; C104700:PAMAM Starburst; D011073:Polyamines; C041514:carbazole