TY - JOUR A1 - Hoffmann, Katrin A1 - Dietzel, Birgit A1 - Schulz, Burkhard A1 - Reck, Guenter A1 - Hoffmann, Angelika A1 - Orgzall, Ingo A1 - Resch-Genger, Ute A1 - Emmerling, Franziska T1 - Combined structural and fluorescence studies of methyl-substituted 2,5-diphenyl-1,3,4-oxadiazoles - Relation between electronic properties and packing motifs JF - Journal of molecular structure N2 - Prerequisite for the rational design of functional organic materials with tailor-made electronic properties is the knowledge of the structure-property relationship for the specific class of molecules under consideration. This encouraged us to systematically study the influence of the molecular structure and substitution pattern of aromatically substituted 1,3,4-oxadiazoles on the electronic properties and packing motifs of these molecules and on the interplay of these factors. For this purpose, seven diphenyl-oxadiazoles equipped with methyl substituents in the ortho- and meta-position(s) were synthesized and characterized. Absorption and fluorescence spectra in solution served here as tools to monitor substitution-induced changes in the electronic properties of the individual molecules whereas X-ray and optical measurements in the solid state provided information on the interplay of electronic and packing effects. In solution, the spectral position of the absorption maximum, the size of Stokes shift, and the fluorescence quantum yield are considerably affected by ortho-substitution in three or four ortho-positions. This results in blue shifted absorption bands, increased Stokes shifts, and reduced fluorescence quantum yields whereas the spectral position and vibrational structure of the emission bands remain more or less unaffected. In the crystalline state, however, the spectral position and shape of the emission bands display a strong dependence on the molecular structure and/or packing motifs that seem to control the amount of dye-dye-interactions. These observations reveal the limited value of commonly reported absorption and fluorescence measurements in solution for a straightforward comparison of spectroscopic results with single X-ray crystallography. This underlines the importance of solid state spectroscopic studies for a better understanding of the interplay of electronic effects and molecular order. KW - Diphenyl-oxadiazoles KW - X-ray structure KW - Packing motif KW - Optical properties KW - Fluorescence quantum yield Y1 - 2011 U6 - https://doi.org/10.1016/j.molstruc.2010.11.071 SN - 0022-2860 VL - 988 IS - 1-3 SP - 35 EP - 46 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Banks, Jo Ann A1 - Nishiyama, Tomoaki A1 - Hasebe, Mitsuyasu A1 - Bowman, John L. A1 - Gribskov, Michael A1 - dePamphilis, Claude A1 - Albert, Victor A. A1 - Aono, Naoki A1 - Aoyama, Tsuyoshi A1 - Ambrose, Barbara A. A1 - Ashton, Neil W. A1 - Axtell, Michael J. A1 - Barker, Elizabeth A1 - Barker, Michael S. A1 - Bennetzen, Jeffrey L. A1 - Bonawitz, Nicholas D. A1 - Chapple, Clint A1 - Cheng, Chaoyang A1 - Correa, Luiz Gustavo Guedes A1 - Dacre, Michael A1 - DeBarry, Jeremy A1 - Dreyer, Ingo A1 - Elias, Marek A1 - Engstrom, Eric M. A1 - Estelle, Mark A1 - Feng, Liang A1 - Finet, Cedric A1 - Floyd, Sandra K. A1 - Frommer, Wolf B. A1 - Fujita, Tomomichi A1 - Gramzow, Lydia A1 - Gutensohn, Michael A1 - Harholt, Jesper A1 - Hattori, Mitsuru A1 - Heyl, Alexander A1 - Hirai, Tadayoshi A1 - Hiwatashi, Yuji A1 - Ishikawa, Masaki A1 - Iwata, Mineko A1 - Karol, Kenneth G. A1 - Koehler, Barbara A1 - Kolukisaoglu, Uener A1 - Kubo, Minoru A1 - Kurata, Tetsuya A1 - Lalonde, Sylvie A1 - Li, Kejie A1 - Li, Ying A1 - Litt, Amy A1 - Lyons, Eric A1 - Manning, Gerard A1 - Maruyama, Takeshi A1 - Michael, Todd P. A1 - Mikami, Koji A1 - Miyazaki, Saori A1 - Morinaga, Shin-ichi A1 - Murata, Takashi A1 - Müller-Röber, Bernd A1 - Nelson, David R. A1 - Obara, Mari A1 - Oguri, Yasuko A1 - Olmstead, Richard G. A1 - Onodera, Naoko A1 - Petersen, Bent Larsen A1 - Pils, Birgit A1 - Prigge, Michael A1 - Rensing, Stefan A. A1 - Mauricio Riano-Pachon, Diego A1 - Roberts, Alison W. A1 - Sato, Yoshikatsu A1 - Scheller, Henrik Vibe A1 - Schulz, Burkhard A1 - Schulz, Christian A1 - Shakirov, Eugene V. A1 - Shibagaki, Nakako A1 - Shinohara, Naoki A1 - Shippen, Dorothy E. A1 - Sorensen, Iben A1 - Sotooka, Ryo A1 - Sugimoto, Nagisa A1 - Sugita, Mamoru A1 - Sumikawa, Naomi A1 - Tanurdzic, Milos A1 - Theissen, Guenter A1 - Ulvskov, Peter A1 - Wakazuki, Sachiko A1 - Weng, Jing-Ke A1 - Willats, William W. G. T. A1 - Wipf, Daniel A1 - Wolf, Paul G. A1 - Yang, Lixing A1 - Zimmer, Andreas D. A1 - Zhu, Qihui A1 - Mitros, Therese A1 - Hellsten, Uffe A1 - Loque, Dominique A1 - Otillar, Robert A1 - Salamov, Asaf A1 - Schmutz, Jeremy A1 - Shapiro, Harris A1 - Lindquist, Erika A1 - Lucas, Susan A1 - Rokhsar, Daniel A1 - Grigoriev, Igor V. T1 - The selaginella genome identifies genetic changes associated with the evolution of vascular plants JF - Science N2 - Vascular plants appeared similar to 410 million years ago, then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and the lycophytes. We report here the genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first nonseed vascular plant genome reported. By comparing gene content in evolutionarily diverse taxa, we found that the transition from a gametophyte- to a sporophyte-dominated life cycle required far fewer new genes than the transition from a nonseed vascular to a flowering plant, whereas secondary metabolic genes expanded extensively and in parallel in the lycophyte and angiosperm lineages. Selaginella differs in posttranscriptional gene regulation, including small RNA regulation of repetitive elements, an absence of the trans-acting small interfering RNA pathway, and extensive RNA editing of organellar genes. Y1 - 2011 U6 - https://doi.org/10.1126/science.1203810 SN - 0036-8075 VL - 332 IS - 6032 SP - 960 EP - 963 PB - American Assoc. for the Advancement of Science CY - Washington ER -