26
|
Umeyama T, Shibata S, Imahori H. Blend films of an amorphous conjugated polymer and a thermal precursor fullerene: effects of annealing temperatures on film structures and photovoltaic properties. RSC Adv 2016. [DOI: 10.1039/c6ra18223b] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Thermal precursor approach using C60–9-methylanthracene adducts enables blend film formations with bulk heterojunction structures containing highly aggregating pristine C60 molecules in combination with an amorphous conjugated polymer, PCDTBT.
Collapse
|
27
|
Umeyama T, Matano D, Baek J, Gupta S, Ito S, Subramanian V(R, Imahori H. Boosting of the Performance of Perovskite Solar Cells through Systematic Introduction of Reduced Graphene Oxide in TiO2Layers. CHEM LETT 2015. [DOI: 10.1246/cl.150651] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
|
28
|
Tao R, Umeyama T, Higashino T, Koganezawa T, Imahori H. Synthesis and Isolation of cis-2 Regiospecific Ethylene-Tethered Indene Dimer-[70]Fullerene Adduct for Polymer Solar Cell Applications. ACS APPLIED MATERIALS & INTERFACES 2015; 7:16676-16685. [PMID: 26177008 DOI: 10.1021/acsami.5b04351] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Although the utilization of [70]fullerene bis-adducts can enhance the power conversion efficiencies of polymer solar cells (PSCs) owing to their strong absorption intensities and high-lying lowest unoccupied molecular orbital energy levels, this synthetic strategy typically yields a mixture of regioisomers that would mask the intrinsic device performances depending on the substituent pattern on the [70]fullerene derivatives. In this study, a single cis-2 regioisomer of C70 bis-adduct (cis-2-[70]BIEC) has been prepared for the first time by the same strategy that had been applied to [60]fullerene to obtain a regioisomerically pure C60 bis-adduct (cis-2-[60]BIEC). Diels-Alder reaction was conducted between a rationally designed ethylene-tethered indene dimer and [70]fullerene, followed by isolation using high-performance liquid chromatography suitable for the separation of fullerene derivatives. A series of structural analysis techniques including NMR spectroscopies and X-ray crystallography were used to identify the absolute configuration of the bis-adduct. A systematic study on the optical, electrochemical, and photovoltaic properties of cis-2-[70]BIEC as well as the corresponding regioisomer mixture (bis-[70]BIEC) and the monoadduct (α-mono-[70]BIEC) has been performed to examine the effect of the pure cis-2 regioisomer. More importantly, their properties are compared with those of cis-2-[60]BIEC to address the effect of fullerene cage structures, that is, C60 versus C70. The PSC based on cis-2-[70]BIEC and poly(3-hexylthiophene) showed a remarkable power conversion efficiency of 4.2%, which is higher than those with bis-[70]BIEC (2.2%), α-mono-[70]BIEC (2.2%), cis-2-[60]BIEC (2.8%), and even a prevalent high-performance C70 monoadduct ([70]PCBM, 3.8%). Our synthetic strategy will pave the way for further development on the rational design and isolation of single fullerene bis-adduct regioisomers exhibiting high device performances.
Collapse
|
29
|
Umeyama T, Watanabe Y, Miyata T, Imahori H. Electron-rich Five-membered Ring of Azulene as a Donor Unit in Donor–Acceptor Alternating Copolymers for Polymer Solar Cell Applications. CHEM LETT 2015. [DOI: 10.1246/cl.140904] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
|
30
|
Tao R, Umeyama T, Higashino T, Koganezawa T, Imahori H. A single cis-2 regioisomer of ethylene-tethered indene dimer–fullerene adduct as an electron-acceptor in polymer solar cells. Chem Commun (Camb) 2015; 51:8233-6. [DOI: 10.1039/c5cc01712b] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
A single cis-2 isomer of fullerene bis-adduct has been synthesized, isolated and applied as an electron-acceptor in polymer solar cells.
Collapse
|
31
|
Umeyama T, Watanabe Y, Miyata T, Imahori H. Synthesis of Thienothiadiazole–Benzothiadiazole Alternating Copolymers and Their Application to Bulk Heterojunction Solar Cells. CHEM LETT 2014. [DOI: 10.1246/cl.140822] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
32
|
Tao R, Umeyama T, Kurotobi K, Imahori H. Effects of alkyl chain length and substituent pattern of fullerene bis-adducts on film structures and photovoltaic properties of bulk heterojunction solar cells. ACS APPLIED MATERIALS & INTERFACES 2014; 6:17313-17322. [PMID: 25208339 DOI: 10.1021/am5058794] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A series of alkoxycarbonyl-substituted dihydronaphthyl-based [60]fullerene bis-adduct derivatives (denoted as C2BA, C4BA, and C6BA with the alkyl chain of ethyl, n-butyl, and n-hexyl, respectively) have been synthesized to investigate the effects of alkyl chain length and substituent pattern of fullerene bis-adducts on the film structures and photovoltaic properties of bulk heterojunction polymer solar cells. The shorter alkyl chain length caused lower solubility of the fullerene bis-adducts (C6BA > C4BA > C2BA), thereby resulting in the increased separation difficulty of respective bis-adduct isomers. The device performance based on poly(3-hexylthiophene) (P3HT) and the fullerene bis-adduct regioisomer mixtures was enhanced by shortening the alkyl chain length. When using the regioisomerically separated fullerene bis-adducts, the devices based on trans-2 and a mixture of trans-4 and e of C4BA exhibited the highest power conversion efficiencies of ca. 2.4%, which are considerably higher than those of the C6BA counterparts (ca. 1.4%) and the C4BA regioisomer mixture (1.10%). The film morphologies as well as electron mobilities of the P3HT:bis-adduct blend films were found to affect the photovoltaic properties considerably. These results reveal that the alkyl chain length and substituent pattern of fullerene bis-adducts significantly influence the photovoltaic properties as well as the film structures of bulk heterojunction solar cells.
Collapse
|
33
|
Oh-oka H, Yamada T, Noto H, Umeyama T, Kadekawa K, Ashitomi K, Nishijima S, Sugaya K. Effect of carbazochrome sodium sulfonate on refractory chronic prostatitis. Int J Urol 2014; 21:1162-6. [DOI: 10.1111/iju.12533] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/18/2014] [Indexed: 11/29/2022]
|
34
|
Zhou S, Hashida Y, Kawakami S, Mihara J, Umeyama T, Imahori H, Murakami T, Yamashita F, Hashida M. Preparation of immunostimulatory single-walled carbon nanotube/CpG DNA complexes and evaluation of their potential in cancer immunotherapy. Int J Pharm 2014; 471:214-23. [PMID: 24861942 DOI: 10.1016/j.ijpharm.2014.05.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Revised: 04/30/2014] [Accepted: 05/19/2014] [Indexed: 01/10/2023]
Abstract
Carbon nanotubes (CNTs) have many interesting properties. In particular, their photohyperthermic effect by near-infrared (NIR) irradiation could be used to kill cancer cells, and could thus be applied in photohyperthermic therapy. However, the solubility of CNTs must be improved before they can be used in biological applications. As DNA is reported to disperse the CNTs in aqueous solution with π-π interactions, we hypothesis that immunostimulatory CpG DNA may also disperse the CNTs in aqueous solution. In this study, we used CpG DNA to disperse single-walled CNTs (SWCNTs) in aqueous solution, in order to combine photohyperthermic effect and immunoactivation together to achieve a more effective cancer therapy. As expected, CpG DNA effectively dispersed the SWCNTs in aqueous solution via the formation of SWCNT/CpG DNA complexes. Moreover, the immunoreactivity of the SWCNT/CpG DNA complexes was investigated. The results showed that intratumoral administration of the SWCNT/CpG DNA complexes in mice enhanced the production level of inflammatory cytokines in tumor tissues. Finally, we evaluated the antitumor effects of the SWCNT/CpG DNA complexes in tumor-bearing mice. The result indicated that intratumoral administration of the SWCNT/CpG DNA complexes combined with NIR irradiation was a more effective approach to prevent the proliferation of tumor growth.
Collapse
|
35
|
Hashida Y, Tanaka H, Zhou S, Kawakami S, Yamashita F, Murakami T, Umeyama T, Imahori H, Hashida M. Photothermal ablation of tumor cells using a single-walled carbon nanotube-peptide composite. J Control Release 2013; 173:59-66. [PMID: 24211651 DOI: 10.1016/j.jconrel.2013.10.039] [Citation(s) in RCA: 88] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 10/28/2013] [Accepted: 10/30/2013] [Indexed: 11/15/2022]
Abstract
Single-walled carbon nanotubes (SWCNTs) are known to have great potential for biomedical applications such as photothermal ablation of tumor cells in combination with near-infrared (NIR) irradiation. In this study, the photothermal activity of a novel SWCNTs composite with a designed peptide having a repeated structure of H-(-Lys-Phe-Lys-Ala-)7-OH [(KFKA)7] against tumor cells was evaluated in vitro and in vivo. The SWCNT-(KFKA)7 composite demonstrated high aqueous dispersibility that enabled SWCNTs to be used in tumor ablation. The NIR irradiation of SWCNT-(KFKA)7 solution resulted in a rapid temperature increase dependent on the SWCNTs concentration up to 50μg/ml. Three minutes of NIR irradiation of a colon 26 or HepG2 cell culture incubated with SWCNT-(KFKA)7 resulted in remarkable cell damage, while that by single treatment with SWCNT-(KFKA)7 or NIR irradiation alone was moderate. The intratumoral injection of SWCNT-(KFKA)7 solution followed by NIR irradiation resulted in a rapid increase of the temperature to 43°C in the subcutaneously inoculated colon 26 tumor based on thermographic observation and remarkable suppression of tumor growth compared with treatment with only SWCNT-(KFKA)7 injection alone or NIR irradiation alone. These results suggest the a great potential of an SWCNT-peptide composite for use in photothermal cancer therapy.
Collapse
|
36
|
Matano Y, Ohkubo H, Miyata T, Watanabe Y, Hayashi Y, Umeyama T, Imahori H. Phosphole- and Benzodithiophene-Based Copolymers: Synthesis and Application in Organic Photovoltaics. Eur J Inorg Chem 2013. [DOI: 10.1002/ejic.201301132] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
37
|
Murakami T, Nakatsuji H, Inada M, Matoba Y, Umeyama T, Tsujimoto M, Isoda S, Hashida M, Imahori H. Photodynamic and Photothermal Effects of Semiconducting and Metallic-Enriched Single-Walled Carbon Nanotubes. J Am Chem Soc 2012; 134:17862-5. [DOI: 10.1021/ja3079972] [Citation(s) in RCA: 150] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
|
38
|
Hashida Y, Umeyama T, Mihara J, Imahori H, Tsujimoto M, Isoda S, Takano M, Hashida M. Development of a Novel Composite Material with Carbon Nanotubes Assisted by Self-Assembled Peptides Designed in Conjunction with β-Sheet Formation. J Pharm Sci 2012; 101:3398-412. [DOI: 10.1002/jps.23144] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 03/11/2012] [Accepted: 03/15/2012] [Indexed: 11/06/2022]
|
39
|
Umeyama T, Douvogianni E, Imahori H. Synthesis and Photovoltaic Properties of Conjugated Polymer Based on 1,3,4-Thiadiazole Unit. CHEM LETT 2012. [DOI: 10.1246/cl.2012.354] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
40
|
Imahori H, Umeyama T, Kurotobi K, Takano Y. Self-assembling porphyrins and phthalocyanines for photoinduced charge separation and charge transport. Chem Commun (Camb) 2012; 48:4032-45. [PMID: 22430327 DOI: 10.1039/c2cc30621b] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Large π-conjugated compounds are promising building blocks for organic thin-film electronics such as organic light-emitting diodes, organic field-effect transistors, and organic photovoltaics. Utilization of porphyrins and phthalocyanines for this purpose is highly fascinating because of their excellent electric, photophysical, and electrochemical properties as well as intense self-assembling abilities arising from π-π stacking interactions. This paper focuses on fundamental aspects of self-assembled structures that have been obtained from porphyrin and phthalocyanine building blocks and more complex composites for photoinduced charge separation and charge transport toward the potential applications to organic thin-film electronics.
Collapse
|
41
|
Umeyama T, Mihara J, Tezuka N, Matano Y, Stranius K, Chukharev V, Tkachenko NV, Lemmetyinen H, Noda K, Matsushige K, Shishido T, Liu Z, Hirose-Takai K, Suenaga K, Imahori H. Preparation and Photophysical and Photoelectrochemical Properties of a Covalently Fixed Porphyrin-Chemically Converted Graphene Composite. Chemistry 2012; 18:4250-7. [DOI: 10.1002/chem.201103843] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2011] [Indexed: 11/11/2022]
|
42
|
Abstract
This mini review presents our recent developments in porphyrin-modified electrodes for solar energy conversion. Various porphyrins have been assembled on nanostructured semiconducting electrodes to achieve efficient photocurrent generation. First, porphyrins have been organized with fullerenes onto semiconducting electrodes to elucidate the relationship between the molecular structures, film structures, and photoelectrochemical properties of the modified electrodes. Formation of hole and electron-transporting highways in the porphyrin/fullerene composite film led to the remarkable enhancement of photocurrent generation. Second, porphyrin-modified single-walled carbon nanotubes have also been assembled onto semiconducting electrodes. The degree of chemical functionalization by the bulky porphyrins was found to have a large impact on the photoelectrochemical properties. Third, asymmetrically π-elongated porphyrins have been successfully employed in dye-sensitized solar cells to improve the cell performance as well as the light-harvesting properties. The power conversion efficiency of the fused porphyrin cell was improved by 50% compared to the reference cell using the corresponding unfused porphyrin. Finally, carboxyquinoxalino derivatives of zinc porphyrin have been further developed to extend the concept of asymmetrically π-elongated porphyrins. The maximum power conversion efficiency of 5.2% was obtained by using 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)-6′-carboxyquinoxalino[2,3-b]porphyrinatozinc(II).
Collapse
|
43
|
Kitaura S, Kurotobi K, Sato M, Takano Y, Umeyama T, Imahori H. Effects of dihydronaphthyl-based [60]fullerene bisadduct regioisomers on polymer solar cell performance. Chem Commun (Camb) 2012; 48:8550-2. [DOI: 10.1039/c2cc34078j] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
44
|
Umeyama T, Watanabe Y, Oodoi M, Evgenia D, Shishido T, Imahori H. Synthesis of low bandgap polymers based on thienoquinodimethane units and their applications in bulk heterojunction solar cells. ACTA ACUST UNITED AC 2012. [DOI: 10.1039/c2jm33637e] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
45
|
Umeyama T, Fueno H, Kawabata E, Kobayashi Y, Tanaka K, Tezuka N, Matano Y, Imahori H. Density Functional Theory Studies on Chemical Functionalization of Single-Walled Carbon Nanotubes by Bingel Reaction. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2011. [DOI: 10.1246/bcsj.20100326] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
46
|
Hayashi H, Nihashi W, Umeyama T, Matano Y, Seki S, Shimizu Y, Imahori H. Segregated donor-acceptor columns in liquid crystals that exhibit highly efficient ambipolar charge transport. J Am Chem Soc 2011; 133:10736-9. [PMID: 21699188 DOI: 10.1021/ja203822q] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Liquid crystalline donor (i.e., phthalocyanine) was covalently linked to acceptor (i.e, fullerene) to achieve efficient charge-transport properties in a liquid crystalline phase. The columnar structure exhibited highly efficient ambipolar charge-transport character, demonstrating the potential utility of the strategy in organic electronics.
Collapse
|
47
|
Imahori H, Iijima H, Hayashi H, Toude Y, Umeyama T, Matano Y, Ito S. Bisquinoxaline-fused porphyrins for dye-sensitized solar cells. CHEMSUSCHEM 2011; 4:797-805. [PMID: 21591269 DOI: 10.1002/cssc.201100029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Indexed: 05/30/2023]
Abstract
5,10,15,20-Tetrakis(2,4,6-trimethylphenyl)-6'-carboxylquinoxalino[2,3-b]quinoxalino[12,13-b']porphyrinatozinc(II) (ZnPBQ) is synthesized to evaluate the effects of π elongation of quinoxaline-fused porphyrins on the optical, electrochemical, and photovoltaic properties. ZnPBQ showed an intensified Soret band as well as red-shifted Soret and Q bands relative to 5,10,15,20-tetrakis(2,4,6-trimethylphenyl)-6'-carboxylquinoxalino[2,3-b]porphyrinatozinc(II) (ZnPQ), demonstrating the improved light-harvesting property of ZnPBQ. The optical and electrochemical HOMO-LUMO gaps were consistent with those estimated by DFT calculations. The photovoltaic properties were compared under optimized conditions, in which a sealed device structure with TiCl(4) -treated, TiO(2) double layers was used. The ZnPBQ cell exhibited a relatively high power conversion efficiency (η) of 4.7%, which was smaller than that of the ZnPQ cell (η=6.3%). The weaker electronic coupling between the LUMO of ZnPBQ and conduction band (CB) of TiO(2) or more tilted geometry of ZnPBQ on the TiO(2) surface may result in the low electron injection/charge collection efficiency as well as the low incident photon-to-current efficiency (IPCE) for the ZnPBQ cell (maximum IPCE=56%) relative to the ZnPQ cell (maximum IPCE=75%), leading to the lower η value of the ZnPBQ cell than that of the ZnPQ cell. In addition, the open-circuit potential of the ZnPBQ cell also slightly decreased with the effect of charge recombination from the electrons injected into the CB of TiO(2) to I(3)(-).
Collapse
|
48
|
Hayashi H, Lightcap IV, Tsujimoto M, Takano M, Umeyama T, Kamat PV, Imahori H. Electron Transfer Cascade by Organic/Inorganic Ternary Composites of Porphyrin, Zinc Oxide Nanoparticles, and Reduced Graphene Oxide on a Tin Oxide Electrode that Exhibits Efficient Photocurrent Generation. J Am Chem Soc 2011; 133:7684-7. [DOI: 10.1021/ja201813n] [Citation(s) in RCA: 124] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
49
|
Umeyama T, Tezuka N, Kawashima F, Seki S, Matano Y, Nakao Y, Shishido T, Nishi M, Hirao K, Lehtivuori H, Tkachenko NV, Lemmetyinen H, Imahori H. Carbon Nanotube Wiring of Donor-Acceptor Nanograins by Self-Assembly and Efficient Charge Transport. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201007065] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
50
|
Umeyama T, Tezuka N, Kawashima F, Seki S, Matano Y, Nakao Y, Shishido T, Nishi M, Hirao K, Lehtivuori H, Tkachenko NV, Lemmetyinen H, Imahori H. Carbon Nanotube Wiring of Donor-Acceptor Nanograins by Self-Assembly and Efficient Charge Transport. Angew Chem Int Ed Engl 2011; 50:4615-9. [DOI: 10.1002/anie.201007065] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Indexed: 11/08/2022]
|