Organic Electronics of Highly-Correlated Molecular Systems May 25th – 26th, 2017 McGill U., Montreal, Canada
Conference Dinner at 18:00
2) Small food court (Thai Express & Culture) 3)   Essence (international cuisine) Large food court, 1st level in Eaton Centre (via McGill Subway) 4) 5)   Lola Rosa vegetarian café
Kunio Awaga"* ^Department of Chemistry, Nagoya University, Chikosa-ku, Nagoya 464-8602, Japan *awaga@mbox.chem.nagoya-u.ac.jp Graph theory has interpreted the cause of beauty of the diamond lattice, in terms of 'strong isotropic property', which is owned by only the three lattices, i.e. diamond, honeycomb (graphene), and K 4 lattices. It was also predicted that the K 4 carbon could be a new allotrope of carbon, in addition to diamond, graphite, graphene, fullerenes and nanotubes. While diamond has a 3D structure of the cubic Fd3m space group, consisting of tetravalent (sp3) carbons, the K 4 carbon has a 3D chiral structure of the cubic I4132 space group, consisting of trivalent (sp 2 ) carbons (Fig. 1(a)). In this K 4 structure, each carbon atom exists at the center of a triangle formed by the three neighboring carbon atoms, and the neighboring triangles, which share one C-C bond, are twisted with a torsion angle α (= ±70.5°) of cosα =1/3. Since attempts to synthesize the K 4 carbon have not succeeded, it was very challenging to make this structure with delocalized π electrons. In the present work, we carried out electrochemical crystallization of the radical anion salts of a chiral molecule, (−)-NDI(naphthalene diimide)-Δ (Fig. 1(b)), using various electrolytes. X-ray crystal analysis of the obtained crystals of (TBA) 1,5 [(−)-NDI-A] revealed the K 4 structure, which was formed by the unique intermolecular π overlap directed toward three directions from the triangular-shape NDI-Δ radical anions (Fig. 1(c)). This lattice was identical to the hyper-kagome lattice (Fig. 1(d)) of S = 1/2 Mott dimers with a 3D spin frustration. In fact, the low-temperature magnetic and heat-capacity measurements clearly revealed the formation of a spin liquid state. Fig. 1 Comparison of the structures of the K 4 carbon (a), the molecular structure of (−)-NDI-Δ (b), the K 4 structure of (−)-NDI-Δ (c), and the hyper-kagome lattice (d).
Jaclyn L. Brusso²* a Department of Chemistry and Biomolecular Sciences, University of Ottawa *jbrusso@uottawa.ca The last 15 years has witnessed a revolution in the development of technologies associated with information processing and communications. Essential to the continuation of these technological advancements is the need for new science, and within this context one of the major fundamental challenges for the future is the development of smaller, lighter, cheaper and more efficient electronic, optical and magnetic materials. Since the use of molecular materials in organic electronics is dependent on the extent of molecular order (in addition to other factors), rational engineering of self-organizing molecular systems with multifunctional characteristics is one of the most attractive and active fields of current research. In pursuit of this goal, we have focused our attention on the design and development of heteroaromatic systems with extensive π-conjugated frameworks to investigate their photophysical properties and augment their solid-state structures such that implementation into optoelectronic devices leads to superior device performance. This presentation will focus on the synthesis, characterization and device studies of systems currently being pursued in our lab.
Yuan Fang", Benjamin D. Lindner b , Kazukuni Tahara b,c, Steven De Feyter"*, Yoshito Tobe b* ªGraduate School of Engineering Science, Osaka University, Tovonaka, Japan b Department of Chemistry, KU Leuven, Leuven, Belgium cSchool of Science and Technology, Meiji University, Kawasaki, Japan d PRESTO, Japan Science and Technology Agency (JST), Kawaguchi, Japan E-mail: tobe@chem.es.osaka-u.ac.jp & steven.defeyter@kuleuven.be One of the important challenges in the field of two-dimensional (2D) self-assembly of organic molecules on surfaces is controlled epitaxial growth of porous molecular networks toward the longitudinal direction, forming porous multilayers on surfaces. To facilitate epitaxial growth with precise control over the interlayer geometry, point-to-point longitudinal interactions is crucial. For this purpose, we chose alkoxyl-substituted dehydrobenzo[12]annulene (DBA) derivatives because of the facile formation of porous networks via van der Waals linkages between the alkyl chains and their synthetic versatility to chemical modification of the alky chains. Utilizing the advantages, we reported the formation, induction, and inversion of supramolecular chirality of the molecular networks. 1,2 On the basis of these results, we report here the formation of bilayer films in which the interlayer geometry was controlled by interaction between the polar substituents attached to the alkyl chain. To this end, we designed chiral DBA, cDBA-OC6( R )-OH and its S enantiomer bearing stereogenic hydroxy groups. At the interface of 1,2,4- trichlorobenzene/graphite, STM observations of cDBA-OC6( R )-OH and its enantiomer indicate the formation of homochiral (counterclockwise (CCW) cDBA-OC6(R)-OH and clockwise (CW) hexagonal forms, respectively) porous monolayer networks at low concentration (5.0 × 10 -6 M). At higher concentration (>1.0 × 10 -5 M), on the other hand, the chiral DBA forms bilayers which can be distinguished by (1) height profile (Figure 1a&b) (2) bias-dependent appearance in the STM images (Figure 1c&d). It should be emphasized that the CCW form consisting of the R enantiomer overlays on the domain of the same supramolecular chirality (CCW) containing the same enantiomer, indicating the bilayer formation is enantioselective. Figure 1. (a&b) STM image and height profile for cDBA-OC6( R )-OH at bias voltage of −0.9 V. (c&d) STM images of a mixture of R and S enantiomers at −0.6 V showing (a) monolayer domains of each enantiomer and (b) at −1.2 V showing enantioselective bilayer formation.