0000000001300192
AUTHOR
Francisco Fernandez-palacio
Efficient light-induced phase transitions in halogen-bonded liquid crystals
Here, we present a new family of light-responsive, fluorinated supramolecular liquid crystals (LCs) showing efficient and reversible light-induced LC-to-isotropic phase transitions. Our materials design is based on fluorinated azobenzenes, where the fluorination serves to strengthen the noncovalent interaction with bond-accepting stilbazole molecules, and increase the lifetime of the cis-form of the azobenzene units. The halogen-bonded LCs were characterized by means of X-ray diffraction, hot-stage polarized optical microscopy, and differential scanning calorimetry. Simultaneous analysis of light-induced changes in birefringence, absorption, and optical scattering allowed us to estimate tha…
Halogen bonding stabilizes a cis-azobenzene derivative in the solid state : A crystallographic study
Crystals oftrans- andcis-isomers of a fluorinated azobenzene derivative have been prepared and characterized by single-crystal X-ray diffraction. The presence of F atoms on the aromatic core of the azobenzene increases the lifetime of the metastablecis-isomer, allowing single crystals of thecis-azobenzene to be grown. Structural analysis on thecis-azobenzene, complemented with density functional theory calculations, highlights the active role of the halogen-bond contact (N...I synthon) in promoting the stabilization of thecis-isomer. The presence of a long aliphatic chain on the azobenzene unit induces a phase segregation that stabilizes the molecular arrangement for both thetrans- andcis-i…
Coordination networks incorporating halogen-bond donor sites and azobenzene groups
Two Zn coordination networks, {[Zn(1)(Py)2]2(2-propanol)}n (3) and {[Zn(1)2(Bipy)2](DMF)2}n (4), incorporating halogen-bond (XB) donor sites and azobenzene groups have been synthesized and fully characterized. Obtaining 3 and 4 confirms that it is possible to use a ligand wherein its coordination bond acceptor sites and XB donor sites are on the same molecular scaffold (i.e., an aromatic ring) without interfering with each other. We demonstrate that XBs play a fundamental role in the architectures and properties of the obtained coordination networks. In 3, XBs promote the formation of 2D supramolecular layers, which, by overlapping each other, allow the incorporation of 2-propanol as a gues…
Hierarchical Self-Assembly of Halogen-Bonded Block Copolymer Complexes into Upright Cylindrical Domains
Summary Self-assembly of block copolymers into well-defined, ordered arrangements of chemically distinct domains is a reliable strategy for preparing tailored nanostructures. Microphase separation results from the system, minimizing repulsive interactions between dissimilar blocks and maximizing attractive interactions between similar blocks. Supramolecular methods have also achieved this separation by introducing small-molecule additives binding specifically to one block by noncovalent interactions. Here, we use halogen bonding as a supramolecular tool that directs the hierarchical self-assembly of low-molecular-weight perfluorinated molecules and diblock copolymers. Microphase separation …
CCDC 1445294: Experimental Crystal Structure Determination
Related Article: Francisco Fernandez-Palacio, Marco Saccone, Arri Priimagi, Giancarlo Terraneo, Tullio Pilati, Pierangelo Metrangolo, Giuseppe Resnati|2016|CrystEngComm|18|2251|doi:10.1039/C6CE00059B
CCDC 1449804: Experimental Crystal Structure Determination
Related Article: Francisco Fernandez-Palacio, Mikko Poutanen, Marco Saccone, Antti Siiskonen, Giancarlo Terraneo, Giuseppe Resnati, Olli Ikkala, Pierangelo Metrangolo, and Arri Priimagi|2016|Chem.Mater.|28|8314|doi:10.1021/acs.chemmater.6b03460
CCDC 1445292: Experimental Crystal Structure Determination
Related Article: Francisco Fernandez-Palacio, Marco Saccone, Arri Priimagi, Giancarlo Terraneo, Tullio Pilati, Pierangelo Metrangolo, Giuseppe Resnati|2016|CrystEngComm|18|2251|doi:10.1039/C6CE00059B
CCDC 1445293: Experimental Crystal Structure Determination
Related Article: Francisco Fernandez-Palacio, Marco Saccone, Arri Priimagi, Giancarlo Terraneo, Tullio Pilati, Pierangelo Metrangolo, Giuseppe Resnati|2016|CrystEngComm|18|2251|doi:10.1039/C6CE00059B
CCDC 1449805: Experimental Crystal Structure Determination
Related Article: Francisco Fernandez-Palacio, Mikko Poutanen, Marco Saccone, Antti Siiskonen, Giancarlo Terraneo, Giuseppe Resnati, Olli Ikkala, Pierangelo Metrangolo, and Arri Priimagi|2016|Chem.Mater.|28|8314|doi:10.1021/acs.chemmater.6b03460
CCDC 1449802: Experimental Crystal Structure Determination
Related Article: Francisco Fernandez-Palacio, Mikko Poutanen, Marco Saccone, Antti Siiskonen, Giancarlo Terraneo, Giuseppe Resnati, Olli Ikkala, Pierangelo Metrangolo, and Arri Priimagi|2016|Chem.Mater.|28|8314|doi:10.1021/acs.chemmater.6b03460