Synthesis of Triptycene-Based Molecular Rotors for Langmuir-Blodgett Monolayers

0451368 - ÚOCHB 2016 RIV US eng J - Journal Article
Kaleta, Jiří - Kaletová, Eva - Císařová, I. - Teat, S. J. - Michl, Josef
Synthesis of Triptycene-Based Molecular Rotors for Langmuir-Blodgett Monolayers.
Journal of Organic Chemistry. Roč. 80, č. 20 (2015), s. 10134-10150. ISSN 0022-3263. E-ISSN 1520-6904
EU Projects: European Commission(XE) 227756 - DIPOLAR ROTOR ARRAY
Institutional support: RVO:61388963
Keywords : surface inclusion * films * arrays
Subject RIV: CC - Organic Chemistry
Impact factor: 4.785, year: 2015

We describe syntheses of six triptycene-containing molecular rotors with several single-crystal X-ray diffraction analyses. These rod-shaped molecules carrying an axial rotator are designed to interleave on an aqueous surface into Langmuir-Blodgett (LB) monolayers containing a two-dimensional trigonal array of dipoles rotatable about an axis normal to the surface. Monolayer formation was verified with the simplest of the rotor structures. On an aqueous subphase containing divalent (c)ations (Mg2+, Ca2+, Zn2+, Sr2+, or Cd2+), the LB isotherm yielded an area of 53 +/- 3 angstrom(2)/molecule (monolayer of type A), compatible with the anticipated triangular packing of axes normal to the surface. On pure water, the area is 30 +/- 3 angstrom(2)/molecule, and it is proposed that in this monolayer (type B), the molecular axes are tilted by 40-45 degrees to a structure similar to those observed in single crystals of related triptycenes. After transfer to a gold surface, ellipsometry and PM IRRAS yield tilt angles of 29 +/- 4 degrees (monolayers of type A) and 38 +/- 4 degrees (type B). A full-scale examination of monolayers from all the rotors on a subphase and after transfer is underway and will be reported separately.
Permanent Link: http://hdl.handle.net/11104/0252537