Yong Sung Park

Synthesis of Norbornene Derivative Using Diels-Alder Reaction

Cyclopentadiene is an important material for making norbornene, and can synthesize norbornene dicarboxylic ester through the maleate and Diels-Alder reaction. Also, a structure similar to that of the representative PVC plasticizer dioctyl phthalate(DOP) was synthesized, so as to confirm the structure of compounds through 1H-NMR, FT-IR, Mass, and HPLC, and to compare the basic properties with those of DOP.

Esterification of 5-Norbornene-2,3-Dicarboxylic Anhydride under Titanium Catalyst

Norbornene dicarboxylate was synthesized through esterification under titanium catalyst. The alcohols are 2-ethyl-1-hexanol, n-octanol, 3,5,5-trimethyl-1-hexanol, and n-decanol. The Structures of compounds were identified by 1H-NMR, and then components were identified by high performance liquid chromatography (HPLC). The yield and purity was over 90 % and 95 %, and color of compounds was colorless or light yellow. The maleate as a by-product was occured by the retro Diels-Alder reaction.

Kinetic Study of the Diels-Alder Reaction of Cyclopentadiene with Bis(2-Ethylhexyl) Maleate

The kinetics of the Diels-Alder reaction of cyclopentadiene with bis(2-ethylhexyl) maleate has been studied at temperatures between 25 and 100 °C and at atmospheric pressure. The influence of temperature on the kinetic constants was determined by fitting the results to the Arrhenius equation. As a result, fitting line similar with the linear curve of the Arrhenius equation at 25, 30 and 40 °C. However, the fitting curve, at 60, 80 and 100 °C, tended towards the outside of the curve in the form of Arrhenius equation. The ratio of endo/exo was a slight change from increase of the reaction temperature.

The Synthesis and Characterization of Nadic Dialkyl-Ester Derivatives with Trialkyl Borate

In this study, nadic dialkyl-ester derivatives were synthesized via the reaction of nadic acid (NA) and trialkyl borate. Trialkyl borate was prepared by simple esterification of boric acid and a wide variety of alcohols. This synthesis process is a green process that does not use any solvent and catalysts. The boric acid can be recycled by filtration and can be used to prepare the trialkyl borate. The products were characterized by High-Performance Liquid Chromatography (HPLC) and Nuclear Magnetic Resonance (NMR).

Conductive Polymers Based on Phenothiazine-Benzothiadiazole: Synthesis, Characterization of Photovoltaics

Two new π-conjugated polymers (Poly[(N-10’-(octan-3-yl)-phenothiazin-3,7-ylene)-alt- (4’,7’-bis(thiophen-2-yl)benzo[c][1,2,5]thiadiazole)] (PoPTZ-BT-BTD), Poly[(N-10`-(octan-3-yl) -phenothiazin-3,7-ylene)-alt-(4’,7’-bis(thiophen-2-yl)-5,6-bis(octyloxy)benzo[c][1,2,5]thiadiazole)] (PoPTZ-BT-BoBTD) ) were synthesized through the Suzuki coupling reaction for organic photovoltaics (OPVs), and their optical and electrochemical properties were analyzed. Their wavelength of maximun absorption was 526 nm and 506 nm in solution state, repectively, and 560 nm and 522 nm in film state, respectively. Their band-gap energy was 2.01 eV and 2.09 eV in solution state, and 1.82 eV and 1.91 eV in film state, respectively. The results of analysis of the chrateristics of photovoltaics, 0.79 % and 0.99 % of the maximum power conversion efficiencies (PCE), repectively.

The Side-Chain Effects on Photovoltaic Properties of Copolymers Based on Phenothiazine and Thiophene

In this study, the alternating conductive polymers based on phenothiazine and bithiophene unit, poly[(N-10-dodecyl-phenothiazin-3,7-ylene)-alt-(2,2’-bithiophen-5-yl)] (P1) and poly[(N-10- dodecyl-phenothiazin-3,7-ylene)-alt-(4,4’-didodecyl-2,2’-bithiophen-5-yl)] (P2), were synthesized by Suzuki coupling reaction in the presence of palladium catalyst. The structures of synthesized compounds were confirmed by 1H NMR. The optical, electrochemical properties of synthesized polymers were investigated by UV-Vis, cyclic voltammetry (CV). The optical band gap of 2.22 eV and 2.50 eV was obtained from absorption onset of UV-Vis spectrum. Then, the two devices using blends of the polymer, as a donor, and PC71BM, as an acceptor, were fabricated by spin-coating. The device with a P1:PC71BM (1:4, w/w) as an active layer exhibited the best performance with an open circuit voltage (VOC) of 0.68 V, short circuit current (JSC) of 3.5 mA/cm2, fill factor (FF) of 31.8 % and power conversion efficiency (PCE) of 0.74 %.

Synthesis of Phenothiazine Derivatives Containing Hetero Atom and Analysis of Conductive Polymer

In this study, new conductive polymers were synthesized based on phenothiazine. Phenothiazine has a structure containing nitrogen and sulfur atoms, hetero atoms and is known to be a good material to transmit holes. However, its solubility is low and there is a difficulty when it is used as a transcription-type material. Hence, various alkyl groups were substituted in the nitrogen location of phenothiazine so that they could be used to synthesize polymers as monomers. Four types of compounds, Poly (10-n-butyl-phenothiazine) sulfide (PBPS), Poly (10-n-hexyl-phenothiazine) sulfide (PHPS), Poly (10-(2-ethylhexyl)-phenothiazine) sulfide (PEHPS), and Poly (10-n-decyl-phenothiazine) sulfide (PDPS) were synthesized and their yields were 57.4%, 80.2%, 45.2%, and 47.1%, respectively. Finally, UV-Vis, PL spectra, and cyclic voltammetry (CV) were measured to analyze the characteristics of conductive polymers.