Three pentacene dimers have been synthesized to investigate the effect of molecular rotation and rotational conformations on singlet fission (SF). In all three dimers, the pentacene units are linked by...
The synthesis of the asymmetric ligand 3phenyl-1-(pyridin-2-yl)-1H-pyrazol-5-amine (L1) and its single-crystal X-ray structure are reported. L1 displays crystallographic symmetry (orthorhombic, Pccn) higher than its molecular symmetry (point group C 1 ) and also displays supercooling, with a difference in the melting and solidification points of over 100 °C. Upon complexation with ZnCl 2 , L1 engages in both primary cation and secondary anion coordination via hydrogen bonding, and the complex exhibits a room-to-low-temperature single crystal-to-crystal phase transition. The ZnCl 2 complex becomes a birefringent fluid mixed with crystalline domains at high temperatures, as detected by polarized optical microscopy. Examination of the photoluminescence properties showed that the emission intensity increased and a pronounced bathochromic shift was observed in the emission maximum upon going from solution to the solid state, for both the ligand and complex, consistent with aggregation-induced emission behavior.
Nickel-mediated Yamamoto coupling provides a concise and efficient synthesis of triphenylene derivatives, including electron-deficient discotic mesogens.
The design and synthesis of urea-based systems suitable for selective anion recognition has demonstrated potential for environmental remediation. These systems act as a double hydrogen-bond donor to anion acceptors, however, the availability of the carbonyl group to also act as a hydrogen-bond acceptor has posed as an optimization challenge. One approach to address this obstacle is to design preorganized coordination complexes that decrease the accessibility of the carbonyl group, yet are still capable of anionic hydrogen bonding by secondary [a]
The synthesis and single crystal structures of
3-phenyl-1-(pyridin-2-yl)-1<i>H</i>-pyrazol-5-amine (<b>L1</b>) and its complex with ZnCl<sub>2 </sub>are reported. <b>L1</b> exhibits supercooling, with a
difference in melting and solidification points of over 100 <sup>o</sup>C. The complex [<b>L1</b>ZnCl<sub>2</sub>] has a room-to-low temperature single
crystal-to-crystal phase transition in the solid state, while a birefringent
fluid phase mixed with crystalline domains is observed at high temperatures. Significant
fluorescence enhancement is observed upon formation of the ZnCl<sub>2</sub>
complex.
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