- Light-Harvesting Nanotubes Formed by Supramolecular Assembly of Aromatic Oligophosphates
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A 2,7-disubstituted phosphodiester-linked phenanthrene trimer forms tubular structures in aqueous media. Chromophores are arranged in H-aggregates. Incorporation of small quantities of pyrene results in the development of light-harvesting nanotubes in which phenanthrenes act as antenna chromophores and pyrenes as energy acceptors. Energy collection is most efficient after excitation at the phenanthrene H-band. Fluorescence quantum yields up to 23 % are reached in pyrene doped, supramolecular nanotubes.
- B?sch, Caroline D.,Langenegger, Simon M.,H?ner, Robert
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- Photochromic Rhenium-Based Molecular Rectangles: Syntheses, Structures, Photophysical Properties, and Electrochemistry
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Two novel fac-Re(CO)3-based rectangles {[(CO)3Re(μ-Cl)2Re(CO)3]2(μ-L)2} (1) and {[(CO)3Re(μ-OC4H9)2Re(CO)3]2(μ-L)2}(2) based on new photochromic dithienylethene-containing ligand 2,7-di(pyridin-4-yl)-9,10-bis(5-chloro-2-methylthien-3-yl)-phenanthrene (L) were prepared. They displayed varying photochromic properties both in solution and in the single-crystal state. Through a judicious choice of the bridging ligands along the short sides of the rectangles, the photophysical and electrochemical properties of the complexes could also be readily tuned.
- Jin, Guo-Xia,Li, Yu-Long,Ma, Jian-Ping,Sun, Yanyan,Wang, Teng
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- Synthesis of Redox-Active Photochromic Phenanthrene Derivatives
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A phenanthrene unit has been functionalized by several methylthiophene units in order to bring it a photochromic behavior. These compounds were characterized by NMR, absorption and emission spectroscopies, theoretical calculations as well as cyclic voltammetry. The association of a phenanthrene group with a photochromic center could open the door to a new generation of organic field-effect transistors.
- Boggio-Pasqua, Martial,Chatir, Elarbi,Cobo, Saioa,Loiseau, Frederique,Philouze, Christian,Royal, Guy
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- Intermolecular coupling and intramolecular cyclization of aryl nitriles on Au(111)
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The on-surface dimerization reaction of an organic nitrile on Au(111) is reported. The formation of the product, which contains five newly formed σ-bonds and a diazapyrene core structure, was investigated and characterized by scanning tunneling microscopy. Experimental and computational studies of reference compounds support our findings.
- Klaasen, Henning,Liu, Lacheng,Gao, Hong-Ying,Viergutz, Lena,Held, Philipp A.,Knecht, Tobias,Meng, Xiangzhi,B?rner, Melanie C.,Barton, Dennis,Amirjalayer, Saeed,Neugebauer, Johannes,Studer, Armido,Fuchs, Harald
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supporting information
p. 11611 - 11614
(2019/10/02)
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- Structure-property relationship of D-A type copolymers based on phenanthrene and naphthalene units for organic electronics
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Four donor-acceptor (D-A) type conjugated polymers (PA1, PA2, PA3 and PA4) based on phenanthrene and naphthalene as the donating units with or without dimethoxy substitution were synthesized for organic field effect transistors (OFETs) and bulk-heterojunction organic photovoltaics (OPVs). Dimethoxy substituents have significant effects on the optical, electrochemical, charge transport and photovoltaic properties depending on the donor-polyaromatic (PA) compounds. The optical band gaps of these PA-based copolymers from the smallest to the largest are as follows: 1.52 eV (1,5-dimethoxy substituted naphthalene (PA4)), 1.59 eV (unsubstituted naphthalene (PA3)), and 1.63 eV (unsubstituted phenanthrene (PA1), and substituted 9,10-dimethoxy phenanthrene (PA2)). While the values vary depending on the compounds, both PA2 and PA4 are found to have higher highest occupied molecular orbital (HOMO) energy levels than those of PA1 and PA3 due to the electron donating nature of dimethoxy substituents. The PA based copolymers without dimethoxy substituents showed highly balanced ambipolar behavior with ～1 cm2 V-1 s-1, whereas the electron mobility of dimethoxy modified PA (MeOPA) based copolymers was suppressed. The inverted bulk heterojunction OPVs based on PA1 and PA3 exhibited power conversion efficiency (PCE) as high as 5.3% and 5.8%, respectively. The PCEs of PA copolymer-based OPV devices were mainly affected by an increase in the open circuit voltage rather than by the photocurrent or fill factor.
- Kim, Yeong-A,Kang, Minji,Jeon, Ye-Jin,Hwang, Kyeongil,Kim, Yeon-Ju,Jang, Soo-Young,Kim, In-Bok,Kwon, Gucheol,Kim, Dong-Yu
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supporting information
p. 10332 - 10342
(2017/10/19)
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- In situ generation of hydroperoxide by oxidation of benzhydrols to benzophenones using sodium hydride under oxygen atmosphere: Use for the oxidative cleavage of cyclic 1,2-diketones to dicarboxylic acids
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A facile oxidative cleavage of cyclic 1,2-diketones 1 to dicarboxylic acids 3 with hydroperoxide generated in situ has been developed. In situ generation of hydroperoxide was effected by the oxidation of 4,4′-dichlorobenzhydrol 2f to 4,4′-dichlorobenzophenone 4f using sodium hydride under oxygen atmosphere.
- Kang, Sunhae,Lee, Soyoung,Jeon, Minju,Kim, Sun Min,Kim, Young Sug,Han, Hogyu,Yang, Jung Woon
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p. 373 - 376
(2013/02/23)
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- Synthesis of rotationally restricted and modular biphenyl building blocks
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A series of modular biphenyl building blocks with stepwise adjusted torsion angles and terminally functionalized with leaving groups have been synthesized. The two phenyl rings of the biphenyl synthon are clamped by alkyl chains of various lengths. The desired building blocks 3 and 4 were obtained by copper-mediated C-C biaryl coupling reactions followed by the construction of interlinking alkyl bridges. The key intermediates 14 and 15 were transformed into the corresponding cycloheptadienones 16 and 17, which were reduced to the desired propyl-bridged biphenyls 3b and 3c. The butyl-bridged derivatives 4b and 4c were obtained from 14 and 15 by an allylation reaction followed by ring-closing metathesis (RCM) and hydrogenation. The pentyl chain in precursor 24 was obtained by two aldol C-C bond-forming reactions followed by a sequence of reduction steps. It was subsequently cyclized in an aryl-aryl coupling reaction to the pentyl-bridged biphenyl 26 along with the macrocyclic dimer 25. The UV absorption spectra of the acetylsulfanyl-functionalized series 1a-8a were recorded and analyzed: A linear correlation between the conjugation band in the UV absorption spectra and the cos2Φ values (Φ is the interplanar torsion angle) is observed.
- Vonlanthen, David,Rotzler, Juergen,Neuburger, Markus,Mayor, Marcel
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experimental part
p. 120 - 133
(2010/03/24)
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- DIHALIDE, POLYMER COMPOUND AND METHOD FOR PRODUCING SAME
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It is an object of the invention to provide a novel π-conjugated polymer compound capable of expecting an application as a functional material having a solubility, a heat resistance, an electrochemical activity and a fluorescence, and a method for producing the same. A dihalide is represented by the following formula: (wherein R1 represents a halogen, R2 represents an alkyl group or a silyl group having a substituent, and R3 represents a hydrogen or an alkyl group).
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- Para ordered aromatic diacids containing benzimidazole groups
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2-Benzimidazole terephthalic acid, 4,4'-dicarboxy-2,2'-bisbenzimidazole benyl and 4,4"-dicarboxy-2'-phenyl-3'-[2-(4-phenylbenzthiazole)]-6'-[2-(3-phenylbenzimidazole]-p-terphenyl are provided. Also provided are methods for preparing these dicarboxylic acids. 2-benzimidazole terephthalic acid is prepared by reacting trimellitic anhydride with o-phenylenediamine in a suitable solvent. 4,4'-dicarboxy-2,2'-bisbenzimidazole biphenyl is prepared by diazotizing 2-amino-5-bromobenzoic acid to prepare 4,4'-dibromodiphenic acid, reacting the 4,4'-dibromodiphenic acid with o-phenylenediamine in trimethylsilyl polyphosphate solution to prepare 4,4'-dibromo-2,2'-bisbenzimidazolyl biphenyl, reacting the 4,4'-dibromo-2,2'-bisbenzimidazolyl biphenyl with cuprous cyanide to prepare the corresponding dicyano compound, and hydrolyzing the dicyano compound. 4,4"-Dicarboxy-2'-phenyl-3'-[2-(4-phenylbenzthiazole)]-6'-[2-(3-phenylbenzimidazole)]-p-terphenyl is prepared by reacting a 4-benzazole benzil with 1,3-bis(p-bromophenyl)-2-propanone to prepare 2,5-bis(p-bromophenyl)-3-phenyl-4-(2-phenylbenzazole) cyclopentadienone, reacting the cyclopentadienone with 2-(3-ethynylphenyl) benzimidazole to prepare the corresponding dibromo terphenyl compound, reacting the dibromo terphenyl compound with cuprous cyanide to prepare the corresponding dicyano terphenyl compound, and hydrolyzing the dicyano compound.
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- Electron transfer in bis-porphyrin donor-acceptor compounds with polyphenylene spacers shows a weak distance dependence
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A series of phenylene-bridged bis-porphyrin adducts have been synthesized, containing one, two, or three phenyl bridges. Complete synthetic details are provided. For studies of photochemical electron transfer, mixed metals wre incorporated, with zinc in one porphyrin macrocycle and FeIII (bis-imidazole) in the other macrocycle. When photoexcited, an electron is transferred from Zn to FeIII. The rate of this process drops only slowly with distance: kα exp(βr), with β = 0.4 A?-1. This dependence can be predicted by a simple theory which assumes that the drop does not reflect increased distance, but rather reflects the break in conjugation which occurs at each phenyl juncture due to the biphenyl twist angle of ca. 50°. Inefficient overlap in this angle results in a rate drop of ca. 6-fold per phenyl ring, in good agreement with the observed results.
- Helms, Anna,Heiler, David,McLendon, George
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p. 6227 - 6238
(2007/10/02)
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