‘Pincer-tweezer’ tetraimidazolium salts as hosts for halidesIn this work we describe the preparation of two tetracationic molecular tweezers that were used as hosts for the recognition of chloride, bromide and iodide. These two hosts contain a rigid bis-alkynyl spacer that connects two arms built with two pincer bis-imidazolium units. The nature of the spacer confers distinct structural features to these two molecular ‘pincer-tweezers’. The tweezer with the anthracenyl linker has a quasi-parallel disposition of the two arms of the tweezer, while in the carbazolyl-linked tweezer the two arms are significantly more separated.
Indacenodipyrene containing small molecules and ladder polymersA series of s-indaceno[1,2,3-cd:5,6,7-c'd']dipyrene-containing small molecules and ladder polymers were prepared using a palladium catalyzed arylation reaction. Precursor polymers and their resulting ladder polymers with molecular weights up to 13 kDa were prepared. The rigid, planar materials possessed highest occupied molecular orbital (HOMO) energies of −5.39 to −5.23 eV, lowest unoccupied molecular orbitals (LUMO) energies of −2.42 eV to −2.98 eV, and optical gaps of 1.68–2.03 eV. Organic field effect transistors were prepared with derivatives giving hole mobilities up to 2.5 X 10−5 cm2V−1s−1.
Superphanes: Facile and efficient preparation, functionalization and unique propertiesSuperphanes, compounds in which the two benzene rings clamped parallel on top of each other by six bridges, have been attracting considerable interest because of their structural beauty and symmetry. However, progress in the research of superphane chemistry and beyond has been seriously hampered by their poor availability. Herein, we report the facile and scalable synthesis of a collection of superphanes with structural diversity and their unique photophysical properties, as well as their unusual host–guest behavior.