1991-43-1Relevant articles and documents
Visible-Light-Driven Halogen Bond Donor Based Molecular Switches: From Reversible Unwinding to Handedness Inversion in Self-Organized Soft Helical Superstructures
Bisoyi, Hari Krishna,Bunning, Timothy J.,Li, Bing-Xiang,Li, Quan,McConney, Michael E.,Wang, Hao
, p. 2684 - 2687 (2020/01/22)
Visible-light-driven molecular switches endowing reversible modulation of the functionalities of self-organized soft materials are currently highly sought after for fundamental scientific studies and technological applications. Reported herein are the des
General and efficient synthesis of polyfluorinated 2-aminotolans and 2-arylindoles
Politanskaya, Larisa V.,Shteingarts, Vitalij D.,Tretyakov, Evgeny V.
, p. 85 - 98 (2016/07/19)
It was established here that cross-coupling of polyfluorinated 2-iodoanilines with arylacetylenes in MeCN in the presence catalytic amounts of Pd(PPh3)2Cl2, CuI and Et3N produces the corresponding 2-aminotolans although their yields are decreased from 98% to 40% with increasing fluorination of the substrates. It was shown that the 2-aminotolans with six or fewer fluorine atoms in their rings can be heterocyclised by heating in ethanol containing p-TSA to produce the corresponding polyfluorinated indoles. Cyclisation of tolans containing larger numbers of fluorine atoms in their rings proceeds most efficiently in the presence of KOH, resulting in 2-phenylindoles containing the current maximum of eight fluorine atoms.
Halogen bonding versus hydrogen bonding in driving self-assembly and performance of light-responsive supramolecular polymers
Priimagi, Arri,Cavallo, Gabriella,Forni, Alessandra,Gorynsztejn-Leben, Mikael,Kaivola, Matti,Metrangolo, Pierangelo,Milani, Roberto,Shishido, Atsushi,Pilati, Tullio,Resnati, Giuseppe,Terraneo, Giancarlo
experimental part, p. 2572 - 2579 (2012/09/22)
Halogen bonding is arguably the least exploited among the many non-covalent interactions used in dictating molecular self-assembly. However, its directionality renders it unique compared to ubiquitous hydrogen bonding. Here, the role of this directionality in controlling the performance of light-responsive supramolecular polymers is highlighted. In particular, it is shown that light-induced surface patterning, a unique phenomenon occurring in azobenzene-containing polymers, is more efficient in halogen-bonded polymer-azobenzene complexes than in the analogous hydrogen-bonded complexes. A systematic study is performed on a series of azo dyes containing different halogen or hydrogen bonding donor moieties, complexed to poly(4-vinylpyridine) backbone. Through single-atom substitution of the bond-donor, control of both the strength and the nature of the noncovalent interaction between the azobenzene units and the polymer backbone is achieved. Importantly, such substitution does not significantly alter the electronic properties of the azobenzene units, hence providing us with unique tools in studying the structure-performance relationships in the light-induced surface deformation process. The results represent the first demonstration of light-responsive halogen-bonded polymer systems and also highlight the remarkable potential of halogen bonding in fundamental studies of photoresponsive azobenzene-containing polymers. Copyright
