Ac avitand with acetamidoquinoxaline flaps selffolds to form ad eep confined cavity rigidified by intramolecular hydrogenb onding. The cavity formed by this compound is suitable for the selectivee ncapsulation of cyclohexane. The chair-to-chairi nterconversion of encapsulated cyclohexanea nd free cyclohexane was investigated by dynamic NMR spectroscopy in CDCl 3 at 400 MHz. Significant slowdown in the chair-to-chair interconversion of encapsulated cyclohexane was recorded due to the CH-p stabilization compared with free cyclohexane.Scheme1.Synthesis of acetamidoquinoxaline cavitand 1.Reagents and conditions: R= C 11 H 23 ;( a) NaH, THF,08C, 4h,6 2%;( b) SnCl 2 ·2H 2 O, DMF, room temperature, 98 %; (c) acetic anhydride, K 2 CO 3 ,R T, 87 %.[a] Dr.Figure 2. VT-NMR(CDCl 3 ,400 MHz) spectrao fencapsulated cyclohexane in cavitand 1.The simulateds pectraa re showni ndark lines.Figure 3. VT-NMR(CDCl 3 ,400 MHz) spectrao fcomplexed(signals on the right)a nd uncomplexed( signals on the left) cyclohexane.

We synthesized one blue emitting polymer (P1) and two green emitting polymers (P2, P3) based on polyfluorene with wide photoluminescence spectra, and fabricated white polymer light emitting diodes (W1, W2) with single emitting layer through a blend method. The weight ratio of P1 and P2 or P3 was adjusted to achieve white light emission and to balance the light color. In this study, we achieved (575 cd/m 2 , 0.68 cd/A) with bluish white emission using W1 (P1 : P2 = 98.0 : 2.0), and (554 cd/m 2 , 0.8 cd/A) using W2 (P1 : P3 = 98.0 : 2.0) with greenish white emission. Luminance of devices, which had the donor concentration above 2.0 wt%, decreased on account of high concentration quenching.

A new photoluminescent polymer with a high thermal stability and superior color conversion ability was synthesized from a Suzuki coupling reaction, and its physical and optical properties were investigated. The applicability of the synthesized polymer as a color conversion material was also examined. A color filter was fabricated using a screen printing method and its optical properties were measured using a range of equipment after placing the fabricated color filter on the blue color light emission device.

New PAF derivatives [poly(fluorene-co-1,3diphenylimidazolium chloride) 7 and poly(fluorene-co-1,3-diphenylimidazol-2-thione) 9] with high thermal stability were synthesized and their physical and optical properties were investigated. The obtained polymers were characterized by 1 H NMR, 13 C NMR, DSC, TGA, GPC, and SEM-EDX. Thermogravimetric analysis (TGA) showed excellent thermal stability of the resulting polymers. Initial weight loss (5 %) was observed around 700 K, with the main decomposition occurring around 760 K (50 %). The glass transition temperature of 9 was higher than that of the host copolymer 7. The copolymers in this study emitted in the blue region with a maximum around 440 nm. The emission spectra of copolymer 9 showed a red shift compared to that of the host copolymer 7. The optical band gaps deduced from the onset of the absorption of copolymers were about 3.06 and 2.91 eV for copolymers 7 and 9, respectively.