Synthesis and properties of novel fluorinated subnaphthalocyanines for organic photovoltaic cells

Novel fluorinated subnaphthalocyanine derivatives were newly designed and synthesized as donor materials for low molecular organic photovoltaic cells using fullerene as an acceptor. They were designed to have the low-lying HOMO energy levels for improvement of open circuit voltage without any expense of short-circuit current density. The HOMO/LUMO energy levels of hexafluoro-, heptafluoro-, dodecafluoro-, tridecafluoro- and the parent subnaphthalocyanine estimated based on the photoelectron spectroscopy were −5.69/−3.93, −5.67/−3.90, −5.96/−4.19, −5.92/−4.11 and −5.30/−3.58 eV, respectively, showing that frontier orbital energy levels can be effectively tuned by fluorination.     

Linear viscoelastic behavior of perfluorooctyl sulfonate micelles: effects of counter-ions

Linear viscoelastic behavior was investigated for aqueous solutions of perfluorooctyl sulfonate (C₈F₁₇SO⁻ ₃; abbreviated as FOS) micelles having a mixture of tetraethylammonium (N⁺(C₂H₅)₄; TEA) and lithium (Li⁺) ions as the counter-ions. The solutions had the same FOS concentration (0.1 mol l⁻¹) and various Li⁺ fractions in the counter-ions, φ_Li = 0−0.6, and the FOS micelles in these solutions formed threads which further organized into dendritic networks. At T ≤ 15 °C, the terminal relaxation time τ and the viscosity η, governed by thermal scission of the networks, increased with increasing φ_Li up to 0.55. A further increase of φ_Li resulted in decreases of τ and η and in broadening of the relaxation mode distribution. These rheological changes are discussed in relation to the role of TEA ions in thermal scission: Previous NMR studies revealed that only a fraction of TEA ions were tightly bound to the FOS micellar surfaces and these bound ions stabilized the thread/network structures. The concentration of non-bound TEA ions, C_TEA ^*, decreased and finally vanished on increasing φ_Li up to φ_Li ^* ≅ 0.6, and the concentration of the bound TEA ions significantly decreased on a further increase of φ_Li. The non-bound TEA ions appeared to catalyze the thermal scission of the FOS threads, and the observed increases of τ and η for φ_Li < 0.55 were attributed to the decrease of C_TEA ^*. On the other hand, the decreases of τ and η as well as the broadening of the mode distribution, found for φ_Li > 0.55 (where C_TEA ^* ≅ 0), were related to destabilization of the FOS threads/networks due to a shortage of the bound TEA ions and to the existence of concentrated Li⁺ ions. Viscoelastic data of pure FOSTEA and FOSTEA/FOSLi/TEACl solutions lent support to these arguments for the role of TEA ions in the relaxation of FOSTEA/FOSLi solutions. Received: 12 October 1999/Accepted: 1 November 1999     

A Ligand That Targets CUG Trinucleotide Repeats

The development of small molecules that can recognize specific RNA secondary and tertiary structures is currently an important research topic for developing tools to modulate gene expression and therapeutic drugs. Expanded CUG trinucleotide repeats, known as toxic RNA, capture the splicing factor MBNL1 and are causative of neurological disorder myotonic dystrophy type 1 (DM1). Herein, the rational molecular design, synthesis, and binding analysis of 2,9‐diaminoalkyl‐substituted 1,10‐phenanthroline (DAP), which bound to CUG trinucleotide repeats, is described. The results of melting temperature (T_m) analyses, surface plasmon resonance (SPR) assay, and electrospray spray ionization time‐of‐flight (ESI‐TOF) mass spectrometry showed that DAP bound to r(CUG)₉ but not to r(CAG)₉ and r(CGG)₉. The dual luciferase assay clearly indicated DAP bound to the r(CUG)_n repeat by affecting the translation in vitro.     

Cationic polymerization of a novel oxetane‐bearing ionic liquid structure and properties of the obtained poly(ionic liquid)

An ionic liquid, 1‐ethyl‐3‐(3‐ethyl‐3‐oxetanylmethyl)imidazolium bis(trifluoromethanesulfonyl)imide (OXImTFSI), was synthesized, and its cationic polymerization was examined. The heating of a mixture of 1‐ethylimidazole and 3‐chloromethyl‐3‐ethyloxetane at 90 °C for 48 h yielded 1‐ethyl‐3‐(3‐ethyl‐3‐oxetanylmethyl)imidazolium chloride, which was transformed to a room‐temperature ionic liquid, OXImTFSI, by ion exchange with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). This ionic liquid was polymerized using boron trifluoride ethyl ether complex as a catalyst to give polyOXImTFSI. Five percent weight loss temperature (T_d5) of polyOXImTFSI evaluated by thermal gravimetric analysis was 409 °C, indicating the high thermal stability. Glass transition temperature (T_g) of the polymer evaluated by differential scanning calorimetry was ?19 °C, indicating the high flexibility of the material. Ionic conductivity of polyOXImTFSI was determined to be 1.86 × 10^?8 S/cm at 23 °C, which was far lower than that of the OXImTFSI monomer (5.05 × 10^?4 S/cm). © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 2986–2990