Synthesis, Characterization, and Self-Assembly of a Tetrathiafulvalene (TTF)–Triglycyl Derivative

In this work, we describe the synthesis, characterization, and self-assembly properties of a new tetrathiafulvalene (TTF)–triglycyl low-molecular-weight (LMW) gelator. Supramolecular organogels were obtained in various solvents via a heating–cooling cycle. Critical gelation concentrations (CGC) (range ≈ 5–50 g/L) and thermal gel-to-sol transition temperatures (Tgel) (range ≈ 36–51 °C) were determined for each gel. Fourier transform infrared (FT-IR) spectroscopy suggested that the gelator is also aggregated in its solid state via a similar hydrogen-bonding pattern. The fibrillar microstructure and viscoelastic properties of selected gels were demonstrated by means of field-emission electron microscopy (FE-SEM) and rheological measurements. As expected, exposure of a model xerogel to I2 vapor caused the oxidation of the TTF unit as confirmed by UV-vis-NIR analysis. However, FT-IR spectroscopy showed that the oxidation was accompanied with concurrent alteration of the hydrogen-bonded network.This work was supported by the Ministerio de Economía, Industria y Competitividad (CTQ2014-52588-R, CTQ2017-84415-R), Generalitat de Catalunya (2014/SGR/624), the Instituto de Salud Carlos III (ISCIII) (CB06_01_0019), and Universität Regensburg. CIBER-BBN is an initiative funded by the VI National R+D+i Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER actions and financed by ISCIII with assistance from the European Regional Development Fund. We thank Ivo Starý, Jiří Janoušek, Martin Bělohradský, and Irena G. Stará (IOCB, Academy of Sciences of the Czech Republic) for their help in the synthesis of the TTF derivative; Judith Mayr (Universität Regensburg) for preliminary gelation tests; and Alex Abramov (Universität Regensburg) for assistance with UV/IR measurements. David Díaz Díaz thanks Deutsche Forschungsgemeinschaft (DFG) for the Heisenberg Professorship Award.Peer reviewe