1,720,960 research outputs found
End-capping of conjugated thiophene-benzene aromatic systems
No full textThe synthesis of end-capped thieno[3,2-f:4,5-f′]bis[1]benzothiophene was achieved from thiophene and 2,5-thiophenedicarboxaldehyde. Specifically, hexyl and dodecyl end-capping groups conferred reversible redox behavior as evidenced by cyclic voltammetry with oxidation potentials of 0.73 V versus Fc-Fc+ couple. An extensive spectrophotometric analysis is reported. © 2010 Elsevier Ltd. All rights reserved.Barrash-Shiftan N, 1998, J PHYS ORG CHEM, V11, P743, DOI 10.1002-(SICI)1099-1395(1998100)11:10743::AID-POC393.0.CO;2-H; BAUERLE P, 1993, SYNTHESIS-STUTTGART, P1099, DOI 10.1055-s-1993-26009; Brusso JL, 2008, CHEM MATER, V20, P2484, DOI 10.1021-cm7030653; Coropceanu V, 2006, CHEM-EUR J, V12, P2073, DOI 10.1002-chem.200500879; Degheili JA, 2009, J PHYS CHEM A, V113, P1244, DOI 10.1021-jp8098363; Fichou D., 1999, HDB OLIGO POLYTHIOPH; Gao P, 2010, CHEM-EUR J, V16, P5119, DOI 10.1002-chem.200903562; Hains AW, 2010, ACS APPL MATER INTER, V2, P175, DOI 10.1021-am900634a; Helgesen M, 2010, MACROMOLECULES, V43, P1253, DOI 10.1021-ma9024812; Horowitz G, 2004, J MATER RES, V19, P1946, DOI 10.1557-JMR.2004.0266; Kagan C. R., 2003, THIN FILM TRANSISTOR; KALYANASUNDARAM K, 1977, J AM CHEM SOC, V99, P2039, DOI 10.1021-ja00449a004; Lakowicz J. R., 1999, PRINCIPLES FLUORESCE; LIPPERT E, 1957, Z ELEKTROCHEM, V61, P962; MATAGA N, 1956, B CHEM SOC JPN, V29, P465, DOI 10.1246-bcsj.29.465; Miyazaki E, 2009, J MATER CHEM, V19, P5913, DOI 10.1039-b910824f; MIYAZAKI E, 2008, Patent No. 2008108442; Moustafa RM, 2009, J PHYS CHEM A, V113, P1235, DOI 10.1021-jp809830x; Parker C.A., 1968, PHOTOLUMINESCENCE SO; Reichardt C., 1988, SOLVENTS SOLVENT EFF; REICHARDT C, 1994, CHEM REV, V94, P2319, DOI 10.1021-cr00032a005; SARAF SD, 1974, J MATH SCI, V1, P75; Shinamura S, 2010, J ORG CHEM, V75, P1228, DOI 10.1021-jo902545a; Shyamala T, 2006, CHEM PHYS, V330, P469, DOI 10.1016-j.chemphys.2006.09.018; Singh TB, 2006, ANNU REV MATER RES, V36, P199, DOI 10.1146-annurev.matsci.36.022805.094757; Subuddhi U, 2006, PHOTOCH PHOTOBIO SCI, V5, P459, DOI 10.1039-b600009f; Wex B, 2006, J MATER CHEM, V16, P1121, DOI 10.1039-b512191d; Wex B, 2006, J PHYS CHEM A, V110, P13754, DOI 10.1021-jp065548s; Wex B, 2005, J ORG CHEM, V70, P4502, DOI 10.1021-jo048010w; Wex B, 2004, J ORG CHEM, V69, P2197, DOI 10.1021-jo035769j; Xia CJ, 2002, ORG LETT, V4, P2067, DOI 10.1021-ol025943a0
Altering the emission behavior with the turn of a thiophene ring: The photophysics of condensed ring systems of alternating benzenes and thiophenes
No full textSix aromatic compounds with embedded thiophenes differing in the number of rings (2-5) and thiophene orientation along the long axis of the molecule (syn, anti) were investigated. Photophysical properties, steady-state absorption, fluorescence, phosphorescence, lifetimes, quantum yields, and a comprehensive time-resolved spectroscopic analysis (femtosecond and nanosecond transient absorption spectroscopy) have been studied as a function of molecular structure. © 2006 American Chemical Society.Aaron JJ, 2002, J FLUORESC, V12, P231, DOI 10.1023-A:1016869002735; Abdel-Shafi AA, 2005, J PHOTOCH PHOTOBIO A, V172, P170, DOI 10.1016-j.photochem.2004.12.006; AGGARWAL N, 1979, ORG PREP PROCED INT, V11, P247; Becker RS, 1996, J PHYS CHEM-US, V100, P18683, DOI 10.1021-jp960852e; BEIMLING P, 1986, CHEM BER-RECL, V119, P3198, DOI 10.1002-cber.19861191025; Berlman I. B., 1971, HDB FLUORESCENCE SPE; BONNIER JM, 1970, J CHIM PHYS PCB, V67, P571; DAVYDOV SN, 1981, RUSS J PHYS CHEM, V55, P444; de Melo JS, 2003, J CHEM PHYS, V118, P1550, DOI 10.1063-1.1528604; de Melo JS, 2003, PHOTOCHEM PHOTOBIOL, V77, P121; Fichou D., 1999, HDB OLIGO POLYTHIOPH; FLICKER WM, 1976, J CHEM PHYS, V64, P1315, DOI 10.1063-1.432397; GENTILI PL, 2004, PHOTOCHEM PHOTOBIOL, V3, P881; Hadziioannou G, 2000, SEMICONDUCTING POLYM; Jabbarzadeh B, 1997, SPECTROSC LETT, V30, P1279, DOI 10.1080-00387019708006723; KIMURA O, 1988, Patent No. 63122727; Kunugi Y, 2004, J MATER CHEM, V14, P1367, DOI 10.1039-b401209g; Lap DV, 1997, J PHYS CHEM A, V101, P107, DOI 10.1021-jp961670n; Laquindanum JG, 1997, ADV MATER, V9, P36, DOI 10.1002-adma.19970090106; Luman CR, 2003, PHOTOCHEM PHOTOBIOL, V77, P510, DOI 10.1562-0031-8655(2003)0770510:LOFLIS2.0.CO;2; Meng H, 2005, J AM CHEM SOC, V127, P2406, DOI 10.1021-ja043189d; Merzlikine AG, 2004, PHOTOCH PHOTOBIO SCI, V3, P892, DOI 10.1039-b404580g; Murov S., 1993, HDB PHOTOCHEMISTRY; Nijegorodov N, 2001, SPECTROCHIM ACTA A, V57, P1449, DOI 10.1016-S1386-1425(00)00488-1; Pan HL, 2006, CHEM MATER, V18, P3237, DOI 10.1021-cm0602592; Perepichka IF, 2005, ADV MATER, V17, P2281, DOI 10.1002-adma.200500461; Perkampus H.-H, 1992, US VIS ATLAS ORGANIC; POMERANTZ M, 1994, MATER RES SOC SYMP P, V328, P227; Rentsch S, 1999, PHYS CHEM CHEM PHYS, V1, P1707, DOI 10.1039-a808617f; RYASHENTSEVA MA, 1988, IZV AKAD NAUK SSSR, V12, P2857; THYRION FC, 1973, J PHYS CHEM-US, V77, P1478, DOI 10.1021-j100631a002; TUROO N, 1991, MODERN MOL PHOTOCHEM; Wex B, 2006, J MATER CHEM, V16, P1121, DOI 10.1039-b512191d; Wex B, 2005, J ORG CHEM, V70, P4502, DOI 10.1021-jo048010w; Wex B, 2004, J ORG CHEM, V69, P2197, DOI 10.1021-jo035769j; WYNBERG H, 1970, J ORG CHEM, V35, P711, DOI 10.1021-jo00828a037; YOSHIDA S, 1994, J ORG CHEM, V59, P3077, DOI 10.1021-jo00090a027; ZANDER M, 1987, Z NATURFORSCH A, V42, P735; ZANDER M, 1985, Z NATURFORSCH A, V40, P497; ZANDER M, 1989, Z NATURFORSCH A, V44, P205119
Vibronic coupling in organic semiconductors: The case of fused polycyclic benzene-thiophene structures
No full textThe nature of vibronic coupling in fused polycyclic benzene-thiophene structures has been studied using an approach that combines high-resolution gas-phase photoelectron spectroscopy measurements with first-principles quantum-mechanical calculations. The results indicate that in general the electron-vibrational coupling is stronger than the hole-vibrational coupling. In acenedithiophenes, the main contributions to the hole-vibrational coupling arise from medium- and high-frequency vibrations. In thienobisben-zothiophenes, however, the interaction of holes with low-frequency vibrations becomes significant and is larger than the corresponding electron-vibrational interaction. This finding is in striking contrast with the characteristic pattern in oligoacenes and acenedithiophenes in which the low-frequency vibrations contribute substantially only to the electron-vibrational coupling. The impact of isomerism has been studied as well. © 2006 Wiley-VCH Verlag GmbH and Co. KGaA,.Anthony JE, 2001, J AM CHEM SOC, V123, P9482, DOI 10.1021-ja0162459; Anthony JE, 2002, ORG LETT, V4, P15, DOI 10.1021-ol0167356; Barbara PF, 1996, J PHYS CHEM-US, V100, P13148, DOI 10.1021-jp9605663; Bendikov M, 2004, CHEM REV, V104, P4891, DOI 10.1021-cr030666m; Berlin YA, 2003, J PHYS CHEM A, V107, P3970, DOI 10.1021-jp034225i; Bredas JL, 2004, CHEM REV, V104, P4971, DOI 10.1021-cr040084k; Cornil J, 2001, J PHYS CHEM A, V105, P5206, DOI 10.1021-jp003142o; Coropceanu V, 2002, PHYS REV LETT, V89, DOI 10.1103-PhysRevLett.89.275503; da Silva DA, 2004, CHEM COMMUN, P1702, DOI 10.1039-b403828b; Demadis KD, 2001, CHEM REV, V101, P2655, DOI 10.1021-cr990413m; Frisch M.J., 2001, GAUSSIAN 98 REVISION; Gruhn NE, 2002, J AM CHEM SOC, V124, P7918, DOI 10.1021-ja0175892; Hutchison GR, 2005, J AM CHEM SOC, V127, P2339, DOI 10.1021-ja0461421; JOHNSTON.RA, 1973, J CHEM SOC FARAD T 2, V69, P1155, DOI 10.1039-f29736901155; Jurchescu OD, 2004, APPL PHYS LETT, V84, P3061, DOI 10.1063-1.1704874; Kato T, 2004, J CHEM PHYS, V120, P3311, DOI 10.1063-1.1640351; Katz HE, 2001, ACCOUNTS CHEM RES, V34, P359, DOI 10.1021-ar990114j; Katz HE, 2000, J PHYS CHEM B, V104, P671, DOI 10.1021-jp992853n; Kwon O, 2004, J CHEM PHYS, V120, P8186, DOI 10.1063-1.1689636; Laquindanum JG, 1998, J AM CHEM SOC, V120, P664, DOI 10.1021-ja9728381; Malagoli M, 2004, J CHEM PHYS, V120, P7490, DOI 10.1063-1.1687675; Meng H, 2003, ADV MATER, V15, P1090, DOI 10.1002-adma.200304935; Merlo JA, 2005, J AM CHEM SOC, V127, P3997, DOI 10.1021-ja044078h; Payne MM, 2005, J AM CHEM SOC, V127, P8028, DOI 10.1021-ja051798v; Payne MM, 2005, J AM CHEM SOC, V127, P4986, DOI 10.1021-ja042353u; Payne MM, 2004, ORG LETT, V6, P3325, DOI 10.1021-ol048686d; Pope M., 1999, ELECT PROCESSES ORGA, P1328; Rademacher P, 2001, SPECTROCHIM ACTA A, V57, P2475, DOI 10.1016-S1386-1425(01)00433-4; SCHMIDT W, 1977, J CHEM PHYS, V66, P828, DOI 10.1063-1.433961; SILINSH EA, 1994, ORGANIC MOL CRYSTALS, P402; Wex B, 2005, J ORG CHEM, V70, P4502, DOI 10.1021-jo048010w; Wex B, 2004, J ORG CHEM, V69, P2197, DOI 10.1021-jo035769j; Wex B, 2003, J ORG CHEM, V68, P8258, DOI 10.1021-jo034742x42444
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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