Surface-relief gratings in halogen-bonded polymer-azobenzene complexes A concentration-dependence study
In recent years, supramolecular complexes comprising a poly(4-vinylpyridine) backbone and azobenzene-based halogen bond donors have emerged as a promising class of materials for the inscription of light-induced surface-relief gratings (SRGs). The studies up to date have focused on building supramolecular hierarchies, i.e., optimizing the polymer–azobenzene noncovalent interaction for efficient surface patterning. They have been conducted using systems with relatively low azobenzene content, and little is known about the concentration dependence of SRG formation in halogen-bonded polymer–azobenzene complexes. Herein, we bridge this gap, and study the concentration dependence of SRG formation…
Photoresponsive Halogen-Bonded Liquid Crystals: The Role of Aromatic Fluorine Substitution
A new strategy for controlling the liquid crystalline and photophysical properties of supramolecular mesogens assembled via halogen bonding is reported. Changing the degree of fluorination at the halogen-bond donor of the supramolecular liquid crystal allows for the fine-tuning of the halogen bond strength and thereby provides control over the temperature range of the mesophase. At least three fluorine atoms have to be present to ensure efficient polarization of the halogen-bond donor and the formation of a mesophase. In addition, it was found that stilbazole acceptors are superior to their azopyridine counterparts in promoting stable liquid crystalline phases. The halogen-bond-driven supra…
Photoresponsive ionic liquid crystals assembled: Via halogen bond: En route towards light-controllable ion transporters
We demonstrate that halogen bonding (XB) can offer a novel approach for the construction of photoresponsive ionic liquid crystals. In particular, we assembled two new supramolecular complexes based on 1-ethyl-3-methylimidazolium iodides and azobenzene derivatives containing an iodotetrafluoro-benzene ring as XB donor, where the iodide anion acted as an XB acceptor. DSC and X-ray diffraction analyses revealed that the preferred stoichiometry between the XB donors and acceptors is 2 : 1, and that the iodide anions act as bidentate XB-acceptors, binding two azobenzene derivatives. Due to the high directionality of the XB, calamitic superanions are obtained, while the segregation occurring betw…
Halogen bonding enhances nonlinear optical response in poled supramolecular polymers
We demonstrate that halogen bonding strongly enhances the nonlinear optical response of poled supramolecular polymer systems. We compare three nonlinear optical chromophores with similar electronic structures but different bond-donating units, and show that both the type and the strength of the noncovalent interaction between the chromophores and the polymer matrix play their own distinctive roles in the optical nonlinearity of the systems. acceptedVersion Peer reviewed
CCDC 1866422: Experimental Crystal Structure Determination
Related Article: Marco Saccone, Matthias Spengler, Michael Pfletscher, Kim Kuntze, Matti Virkki, Christoph Wölper, Robert Gehrke, Georg Jansen, Pierangelo Metrangolo, Arri Priimagi, Michael Giese|2019|Chem.Mater.|31|462|doi:10.1021/acs.chemmater.8b04197
CCDC 1541305: Experimental Crystal Structure Determination
Related Article: Marco Saccone, Francisco Fernandez Palacio, Gabriella Cavallo, Valentina Dichiarante, Matti Virkki, Giancarlo Terraneo, Arri Priimagi, Pierangelo Metrangolo|2017|Faraday Discuss.|203|407|doi:10.1039/C7FD00120G
CCDC 1541306: Experimental Crystal Structure Determination
Related Article: Marco Saccone, Francisco Fernandez Palacio, Gabriella Cavallo, Valentina Dichiarante, Matti Virkki, Giancarlo Terraneo, Arri Priimagi, Pierangelo Metrangolo|2017|Faraday Discuss.|203|407|doi:10.1039/C7FD00120G
CCDC 1866421: Experimental Crystal Structure Determination
Related Article: Marco Saccone, Matthias Spengler, Michael Pfletscher, Kim Kuntze, Matti Virkki, Christoph Wölper, Robert Gehrke, Georg Jansen, Pierangelo Metrangolo, Arri Priimagi, Michael Giese|2019|Chem.Mater.|31|462|doi:10.1021/acs.chemmater.8b04197
CCDC 1866420: Experimental Crystal Structure Determination
Related Article: Marco Saccone, Matthias Spengler, Michael Pfletscher, Kim Kuntze, Matti Virkki, Christoph Wölper, Robert Gehrke, Georg Jansen, Pierangelo Metrangolo, Arri Priimagi, Michael Giese|2019|Chem.Mater.|31|462|doi:10.1021/acs.chemmater.8b04197