5467-61-8Relevant articles and documents
Substituents engineered deep-red to near-infrared phosphorescence from tris-heteroleptic iridium(iii) complexes for solution processable red-NIR organic light-emitting diodes
Kim, Hae Un,Sohn, Sunyoung,Choi, Wanuk,Kim, Minjun,Ryu, Seung Un,Park, Taiho,Jung, Sungjune,Bejoymohandas
, p. 10640 - 10658 (2018/10/24)
Research on near-infrared- (NIR-) emitting materials and devices has been propelled by fundamental and practical application demands surrounding information-secured devices and night-vision displays to phototherapy and civilian medical diagnostics. However, the development of stable, highly efficient, low-cost NIR-emitting luminophores is still a formidable challenge owing to the vulnerability of the small emissive bandgap toward several nonradiative decay pathways, including the overlapping of ground- and excited-state vibrational energies and high-frequency oscillators. Suitable structural designs are mandatory for producing an intense NIR emission. Herein, we developed a series of deep-red to NIR emissive iridium(iii) complexes (Ir1-Ir4) to explore the effects of electron-donating and electron-withdrawing substituents anchored on the quinoline moiety of (benzo[b]thiophen-2-yl)quinoline cyclometalating ligands. These substituents help engineer the emission bandgap systematically from the deep-red to the NIR region while altering the emission efficiencies drastically. Single-crystal X-ray structures authenticated the exact coordination geometry and intermolecular interactions in these new compounds. We also performed an in-depth and comparative photophysical study in the solution, neat powder, doped polymer film, and freeze matrix at 77 K states to investigate the effects of substitution on the excited-state properties. These studies were conducted in conjunction with density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. Most importantly, the -CH3 substituted Ir1, unsubstituted Ir2, and -CF3 substituted complex (Ir4) were promising novel compounds with bright phosphorescence quantum efficiency in doped polymer films. Using these novel molecules, deep-red to NIR emissive organic light-emitting diodes (OLEDs) were fabricated using a solution-processable method. The unoptimized device exhibited maximum external quantum efficiency (EQE) values of 2.05% and 2.11% for Ir1 and Ir2, respectively.
Further studies on the interaction of the 5-hydroxytryptamine3 (5-HT3) receptor with arylpiperazine ligands. Development of a new 5-HT3 receptor ligand showing potent acetylcholinesterase inhibitory properties
Cappelli, Andrea,Gallelli, Andrea,Manini, Monica,Anzini, Maurizio,Mennuni, Laura,Makovec, Francesco,Menziani, M. Cristina,Alcaro, Stefano,Ortuso, Francesco,Vomero, Salvatore
, p. 3564 - 3575 (2007/10/03)
Novel arylpiperazine derivatives bearing lipophilic probes were designed, synthesized, and evaluated for their potential ability to interact with the 5-hydroxytryptamine3 (5-HT3) receptor. Most of the new compounds show subnanomolar 5-HT3 receptor affinity. Ester 6bc showing a picomolar Ki value is one of the most potent 5-HT 3 receptor ligands so far synthesized. The structure-affinity relationship study suggests the existence of a certain degree of conformational freedom of the amino acid residues interacting with the substituents in positions 3 and 4 of the quipazine quinoline nucleus. Thus, the tacrine-related heterobivalent ligand 60 was designed in an attempt to capitalize on the evidence of such a steric tolerance. Compound 6o shows a nanomolar potency for both the 5-HT3 receptor and the human AChE and represents the first example of a rationally designed high-affinity 5-HT3 receptor ligand showing nanomolar AChE inhibitory activity. Finally, the computational analysis performed on compound 6o allowed the rationalization of the structure-energy determinants for AChE versus BuChE selectivity and revealed the existence of a subsite at the boundary of the 5-HT3 receptor extracellular domain, which could represent a "peripheral" site similar to that evidenced in the AChE gorge.
