ABSTRACT
Self-complementary assembly is one of the most promising phenomena for the formation of discrete assemblies, e.g., proteins and capsids. However, self-complementary assembly based on multiple host-guest systems has been scarcely reported due to the difficulty in controlling each assembly. Herein, we report a dual interaction system in which the key assembly direction is well regulated by both π-π stacking and hydrogen bonding to construct a self-complementary macrocycle. Continuous host-guest behavior of anthracene-based molecular tweezers during crystallization leads to successful construction of a cyclic hexamer, which is reminiscent of Kekulé's monkey model. Furthermore, the cyclic hexamer in a tight and triple-layered fashion shows hierarchical assembly into cuboctahedron and rhombohedral assemblies in the presence of trifluoroacetic acid. Our findings would be potentially one of metal-free strategies for constructing anthracene-based supramolecular assemblies with higher-order structure.
Subject(s)
Anthracenes , Hydrogen Bonding , Trifluoroacetic AcidABSTRACT
To investigate organic field-effect transistor (OFET) properties, a new thienoacene-type molecule, 4,14-dihexyldinaphtho[2,3-d:2',3'-d']anthra[1,2-b:5,6-b']dithiophene (C6-DNADT), consisting of π-conjugated nine aromatic rings and two hexyl chains along the longitudinal molecular axis has been successfully synthesized by sequential reactions, including Negishi coupling, epoxidation, and cycloaromatization. The fabricated OFET using thin films of C6-DNADT exhibited p-channel FET properties with field-effect mobilities (µ) of up to 2.6 × 10-2 cm2 V-1 s-1, which is ca. three times lower than that of the parent DNADT molecule (8.5 × 10-2 cm2 V-1 s-1). Although this result implies that the installation of relatively short alkyl chains into the DNADT core is not suitable for transistor application, the origins for the FET performance obtained in this work is fully discussed, based on theoretical calculations and solid-state structure of C6-DNADT by grazing incidence wide-angle X-ray scattering (GIWAXS) and atomic force microscopy (AFM) analyses. The results obtained in this study disclose the effect of alkyl chains introduced onto the molecule on transistor characteristics.
Subject(s)
Algorithms , Models, Chemical , Thiophenes/chemical synthesis , Transistors, Electronic , Calorimetry, Differential Scanning/methods , Microscopy, Atomic Force/methods , Models, Molecular , Molecular Structure , Spectrophotometry/methods , Thermogravimetry/methods , Thiophenes/chemistryABSTRACT
Copper-catalyzed regioselective aminothiolation of terminal and internal alkenes with N-fluorobenzenesulfonimide and thiols has been developed. The three-component reaction is promoted by the addition of dimethyl sulfide. In addition to aromatic alkenes, aliphatic alkenes are subjected to the reaction, affording various aminothiolation adducts as single regioisomers. The radical process is proposed by preliminary mechanistic studies, involving radical trap and radical clock experiments.
ABSTRACT
We have synthesized dibenzo[2,3- d:2',3'- d']anthra[1,2- b:5,6- b']dithiophene (DBADT) and several derivatives bearing alkyl and phenyl groups at various positions. The optical and electrochemical properties of the synthesized compounds were investigated. All the fabricated OFET devices exhibited typical p-type behavior under ambient conditions, and diphenyl-substituted analogue-based OFET devices showed excellent mobility, as high as 0.66 cm2 V-1 s-1. The surface morphology and molecular orientation in thin films were also investigated using atomic force microscopy (AFM) and two-dimensional grazing incidence X-ray diffraction (2D-GIXD). It was found that the substituents and their positions affect the molecular orbitals, molecular orientation, and morphology of the thin films, producing different FET performance.
