Naphthalene Diimide Incorporated Thiophene-Free Copolymers with Acene and Heteroacene Units: Comparison of Geometric Features and Electron-Donating Strength of Co-units

Kim, Yiho,Hong, Jayeon,Oh, Joon Hak,Yang, Changduk American Chemical Society 2013 Chemistry of materials Vol.25 No.15

<P>A family of naphthalene diimide (NDI)-based donor (D)-acceptor (A) copolymers with various acene- (benzene (Bz), naphthalene (Np), and pyrene (Py)) and heteroacene-type (selenophene (Se) and thiophene (Th)) donor rings has been designed and synthesized as a means to systematically understand structure–property relationships on the subject of the structural factor and electron-donating capability of the donor portions for applications in organic field-effect transistors (OFETs) based on NDIs. Alongside of two categories dealing with the lack or existence of the heteroatoms in the donor framework, the resulting copolymers can also be classified into ‘thiophene-free’ D–A copolymers (<B>PNDI-Bz</B>, <B>PNDI-Np</B>, <B>PNDI-Py</B>, and <B>PNDI-Se</B>) and thiophene-containing copolymer (<B>PNDI-Th</B>). The results from optical and electronic properties lead to the determination that the empirical electron-donating strength of donor co-units is in the order of Bz < Np < Py < Th < Se. In contrast with the similarity of the LUMO levels (−3.73∼−3.82 eV) due to the dominant NDI contribution to the polymer backbone, the HOMO levels are sensitive to the relative electron-donating ability and shown to primarily influence whether unipolar <I>n</I>-channel (<B>PNDI-Bz</B> and <B>PNDI-Np</B>) or ambipolar charge transport (<B>PNDI-Py</B>, <B>PNDI-Se</B>, and <B>PNDI-Th</B>) is observed in OFETs of the NDI-based copolymers. Intriguingly, regardless of the strong electron donors toward efficient intramolecular charge transfer (ICT), the best OFET performance is observed in the acene-based centrosymmetric copolymer <B>PNDI-Np</B> (5.63 × 10<SUP>–2</SUP> cm<SUP>2</SUP> V<SUP>–1</SUP> s<SUP>–1</SUP>) when compared to those of the other copolymers with axisymmetric units. Thus, the present work highlights that the geometric features of the donors in NDI D–A copolymers strongly reflect the carrier mobility dynamics rather than inserting electron-rich donor moieties into the backbone to lower the band gap and further strengthen ICT.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2013/cmatex.2013.25.issue-15/cm401829x/production/images/medium/cm-2013-01829x_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm401829x'>ACS Electronic Supporting Info</A></P>

원편광 발광 분자의 설계와 응용

유영민(Youngmin You),홍자연(Jayeon Hong),이수민(Sumin Lee) 한국고분자학회 2019 고분자 과학과 기술 Vol.30 No.2

원편광 발광 특성 분자는 센서, 발광 소자, 스핀 통신, 비대칭 광반응 등 다양한 광응용에 새로운 기능성을 더할 수 있다. 본 총설에서는 분자로부터 원편광 발광을 도출할 수 있는 두 가지 분자 설계 원리를 다루었다. 발광성 분자 유닛이 비대칭 공간 위치로 속박되면 엑시톤 커플링으로 인해 원편광 발광을 생산할 수 있다. 이를 위해 binaphthyl과 같이 비대칭축을 가지는 유기 분자 브리지가 사용된다. 원편광 발광을 내기 위한 또다른 원리는 나선형 π -공액 구조를 활용하는 것이다. Helicene이 이러한 원리를 따르는 대표적 분자이다. Helicene에서는 발광 전이의 전자 쌍극자 모멘트와 자기 쌍극자 모멘트가 평행하게 놓여 우수한 비대칭 발광 상수가 발생 가능하다.

Ambipolar Semiconducting Polymers with <i>π-</i>Spacer Linked Bis-Benzothiadiazole Blocks as Strong Accepting Units

Kim, Jonggi,Han, A-Reum,Hong, Jayeon,Kim, Gyoungsik,Lee, Junghoon,Shin, Tae Joo,Oh, Joon Hak,Yang, Changduk American Chemical Society 2014 Chemistry of materials Vol.26 No.17

<P>Recognizing the importance of molecular coplanarity and with the aim of developing new, ideal strong acceptor-building units in semiconducting polymers for high-performance organic electronics, herein we present a simplified single-step synthesis of novel vinylene- and acetylene-linked bis-benzothiadiazole (<B>VBBT</B> and <B>ABBT</B>) monomers with enlarged planarity relative to a conventionally used acceptor, benzothiadiazole (BT). Along these lines, four polymers (<B>PDPP-VBBT</B>, <B>PDPP-ABBT</B>, <B>PIID-VBBT</B>, and <B>PIID-ABBT</B>) incorporating either <B>VBBT</B> or <B>ABBT</B> moieties are synthesized by copolymerizing with centro-symmetric ketopyrrole cores, such as diketopyrrolopyrrole (DPP) and isoindigo (IID), and their electronic, physical, and transistor properties are studied. These polymers show relatively balanced ambipolar transport, and <B>PDPP-VBBT</B> yields hole and electron mobilities as high as 0.32 and 0.13 cm<SUP>2</SUP> V<SUP>–1</SUP> s<SUP>–1</SUP>, respectively. Interestingly, the acetylenic linkages lead to enhanced electron transportation in ketopyrrole-based polymers, showing a decreased threshold voltage and inverting voltage in the transistor and inverter devices, respectively. The IID-based BBT polymers exhibit the inversion of the dominant polarity depending on the type of unsaturated carbon bridge. Owing to their strong electron-accepting ability and their highly π-extended and planar structures, <B>VBBT</B> and <B>ABBT</B> monomers should be extended to the rational design of high-performance polymers in the field of organic electronics.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/cmatex/2014/cmatex.2014.26.issue-17/cm500800u/production/images/medium/cm-2014-00800u_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/cm500800u'>ACS Electronic Supporting Info</A></P>

Inversion of Dominant Polarity in Ambipolar Polydiketopyrrolopyrrole with Thermally Removable Groups

Lee, Junghoon,Han, A‐,Reum,Hong, Jayeon,Seo, Jung Hwa,Oh, Joon Hak,Yang, Changduk WILEY‐VCH Verlag 2012 Advanced functional materials Vol.22 No.19

<P><B>Abstract</B></P><P>A narrow bandgap polymeric semiconductor, <B>BOC‐PTDPP</B>, comprising alkyl substituted diketopyrrolopyrrole (DPP) and <I>tert</I>‐butoxycarbonyl (<I>t</I>‐BOC)‐protected DPP, is synthesized and used in organic field‐effect transistors (OFETs). The polymer films are prepared by solution deposition and thermal annealing of precursors featuring thermally labile <I>t</I>‐BOC groups. The effects of the thermal cleavage on the molecular packing structure in the polymer thin films are investigated using thermogravimetric analysis (TGA), UV‐vis spectroscopy, atomic force microscopy (AFM), Fourier transform infrared (FT‐IR) spectroscopy, and X‐ray diffraction (XRD) analysis. Upon utilization of solution‐shearing process, integrating the ambipolar <B>BOC‐PTDPP</B> into transistors shows <I>p</I>‐channel dominant characteristics, resulting in hole and electron mobilities as high as 1.32 × 10<SUP>−2</SUP> cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP> and 2.63 × 10<SUP>−3</SUP> cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>, which are about one order of magnitude higher than those of the drop‐cast films. Very intriguingly, the dominant polarity of charge carriers changes from positive to negative after the thermal cleavage of <I>t</I>‐BOC groups at 200 °C. The solution‐sheared films upon subsequent thermal treatment show superior electron mobility (<I>μ</I><SUB>e</SUB> = 4.60 × 10<SUP>−2</SUP> cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>), while the hole mobility decreases by one order of magnitude (<I>μ</I><SUB>h</SUB> = 4.30 × 10<SUP>−3</SUP> cm<SUP>2</SUP> V<SUP>−1</SUP> s<SUP>−1</SUP>). The inverter constructed with the combination of two identical ambipolar OFETs exhibits a gain of ∼10. Reported here for the first time is a viable approach to selectively tune dominant polarity of charge carriers in solution‐processed ambipolar OFETs, which highlights the electronically tunable ambipolarity of thermocleavable polymer by simple thermal treatment.</P>

Bilateral salpingectomy to reduce the risk of ovarian/ fallopian/peritoneal cancer in women at average risk: a position statement of the Korean Society of Obstetrics and Gynecology (KSOG)

( Miseon Kim ),( Young-han Kim ),( Yong Beom Kim ),( Jayeon Kim ),( Jae-weon Kim ),( Mi Hye Park ),( Joo Hyun Park ),( Jeong Ho Rhee ),( Myong Cheol Lim ),( Joon-seok Hong ) 대한산부인과학회 2018 Obstetrics & Gynecology Science Vol.61 No.5

Based on the current understanding of a preventive effect of bilateral salpingectomy on ovarian/fallopian/peritoneal cancers, the Korean Society of Obstetrics and Gynecology, Korean Society of Gynecologic Endocrinology, Korean Society of Gynecologic Oncology, Korean Society of Maternal Fetal Medicine, and Korean Society for Reproductive Medicine support the following recommendations: · Women scheduled for hysterectomy for benign gynecologic disease should be informed that bilateral salpingectomy reduces the risk of ovarian/fallopian/peritoneal cancer, and they should be counseled regarding this procedure at the time of hysterectomy. · Although salpingectomy is generally considered as a safe procedure in terms of preserving ovarian reserve, there is a lack of evidences representing its long-term outcomes. Therefore, patients should be informed about the minimal potential of this procedure for decreasing ovarian reserve. · Prophylactic salpingectomy during vaginal hysterectomy is favorable in terms of prevention of ovarian/fallopian/ peritoneal cancer, although operation-related complications minimally increase with this procedure, compared to the complications associated with vaginal hysterectomy alone. Conversion to open or laparoscopic approach from vaginal approach to perform prophylactic salpingectomy is not recommended. · Women who desire permanent sterilization at the time of cesarean delivery could be counseled for prophylactic salpingectomy before surgery on an individual basis.