Viologen-based benzylic dendrimers: selective synthesis of 3,5-bis(hydroxymethyl) benzylbromide and conformational analysis of the corresponding viologen dendrimer subunit

Autor(en): Kathiresan, Murugavel
Walder, Lorenz 
Ye, Fei
Reuter, Hans 
Stichwörter: BEARING; Benzylic bromides; BINDING; CATION; Chemistry; Chemistry, Organic; COMPLEXATION; Dendrimer; DERIVATIVES; ELECTRODES; ESTER; MOLECULAR SWITCH; PM3 simulation; SKELETON; Synthesis; Viologen; X-ray
Erscheinungsdatum: 2010
Volumen: 51
Ausgabe: 16
Startseite: 2188
Seitenende: 2192
Convergent and divergent strategies for the synthesis of viologen dendrimers with 1,3,5-tri-methylene-branching units are discussed. The title compound is easily transformed into 1-[3,5-bis(hydroxymethyl)benzyl]-4-(pyridin-4-yl)pyridinium hexafluorophosphate, which is used in sequential growth and activation steps as a CB(2) compound in the cascade-type dendrimer synthesis (B = -OH, activation = -OH -> Br). Analysis of the dendrimer structure reveals that three torsional angles, that is, tau(1) between the two pyridinium units, tau(2) between the methylene and pyridinium and tau(3) between the methylene and phenyl, determine the conformational space of the dendrimers. We report here the crystal structure of 1-[3,5-bis(hydroxymethyl)benzyl]-4-(pyridin-4-yl)pyridinium as PF(6)(-) salt which represents the smallest subunit of the dendrimer that shows the same three torsional angles. The crystal structure together with the results from PM3 calculations opens an avenue to judge the structure of benzylic viologen-based dendrimers. (C) 2010 Elsevier Ltd. All rights reserved.
ISSN: 00404039
DOI: 10.1016/j.tetlet.2010.02.097

Show full item record

Google ScholarTM