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Oligomer crystals

Fig. 6 UV spectra of (a) 2,5-DSP crystal, (b) 2,5-DSP oligomer crystal, and (c) poly-2,5-DSP crystal. Fig. 6 UV spectra of (a) 2,5-DSP crystal, (b) 2,5-DSP oligomer crystal, and (c) poly-2,5-DSP crystal.
The refinement methodology has, likewise, been furthered by the study of crystalline amyloses. For example, we now know that given only minimally adequate diffraction data, but having on hand detailed information from monomer and oligomer crystal structures, and having the capability to refine models with complete stereochemical flexibility, structures can be solved with... [Pg.480]

Essen L., Siegert R, Lehmann WD, Oesterhelt D (1998) Lipid patches in membrane protein oligomers crystal structure of the bacteriorhodopsin-lipid complex. Proc. Natl. Acad. Sci. USA 95(20) 11673-11678... [Pg.450]

New developments in spectroscopic techniques have made it possible to obtain Raman spectra and more recently also FTIR spectra of oligomer crystals. The crystal area used for FTIR studies with all reflecting Cassegrain type microscopes is about 30 x 30 um, while the laser beam focused through the microscope covers about 5 j,m in diameter. Several examples of IR and Raman crystal studies, some of them correlating with X-ray crystal diffraction studies, are listed in Sec. 4.7.1.3.5. [Pg.346]

It is of great interest that when the heat-treated sample (1) of poly-DSP in Fig. 16 is heated to 330°C (with the same scanning speed), the X-ray diffraction pattern of the resulting sample (2) changes into a pattern which is exactly the same as that of the as-polymerized oligomer crystals prepared by selective monomer excitation (see Sect. m.b.). [Pg.42]

Good coincidence of the X-ray patterns of these two kinds of oligomers suggests that the thermal chain scission in as-polymerized poly-DSP crystals does not proceed randomly at the position of cyclobutane ring in the molecular chain but is somewhat favored on the position of cyclobutane ring in the middle of the chain655. Thus, the oligomer crystal is preferentially accumulated in thermal depolymerization under the polymer crystal-lattice control. This abnormal chain scission is most plausibly explained when the... [Pg.42]

Essen, L., Siegert, R., Lehmann, W.D., Oesterhelt, D. 1998. Lipid patches in membrane protein oligomers crystal structure of the bacteriorhodopsin-Iipid complex. Proc. Natl. Acad. Sci. USA 95 11673-11678. Ferguson, A.D., Welte, W., Hofmann, E., Lindner, B., Holst, O., Coulton, J.W., et al. 2000. A conserved structural motif for lipopolysaccharide recognition by procaryotic and eucaryotic proteins. Structure Fold. Des. 8 585-592. [Pg.37]

StrobI GR, Schwickert H, Trzebiatowski T (1983) Molecular motion, defect structures and phase transitions in oligomer crystals. Ber. Bunsenges. Phys. Chem. 87 244... [Pg.108]

A.C. Prench, A.L. Thompson, B.G. Davis, High purity discrete PEG oligomer crystals allow structural insight, Angew. Chem. Int. Ed. 48 (2009) 1248-1252. [Pg.29]

Figure 5.48 documents that the short-chain oligomers crystallize fully extended. As the chain length increases to the fold-length of the polyurethanes, the molecules fold. [Pg.490]

Internal Loops in RNA Oligomer Crystals. The first crystal structure of an RNA internal loop was solved in 1991(8). The dodecamer rGGACUUCGGUCC (internal loop underlined) forms a duplex in the crystal with an internal loop of consecutive U-G, U-C, C-U and G-U mismatches as shown in Figure 2. The chains of the double helix show two-fold symmetry in the crystal, thus the U-G and U-C pairs are identical to the C-U and G-U pairs. As can be seen, the internal loop generally continues the double helices which surround it by formation of non-Watson-Crick base pairs. The major groove of the A-form helix is opened with respect to a canonical RNA helix. [Pg.59]

PLA stereo-complexes are obtained by co-crystallization of PLLA and PDLA in bulk or in organic solvents such as chloroform or acetonitrile. It has been shown that the minimal degree of polymerization (DP) of PLLA or PDLA oligomers for crystallization is 11, with corresponding melting temperature (Tm) at 59 °C and melting enthalpy (AH i) of 39 J g. In contrast, in blends of PLLA and PDLA oligomers, crystallization or stereo-complexation is... [Pg.39]

Figure 10.6 Schematic diagram of the setup for optically pumped photoluminescence measurements. The excitation polarization was varied by a half-wave plate. The emitted light was collected by the CCD spectrometer along the direction parallel to the sample surface. Reproduced from H. Yanagi, 5. Hotta, S. Kobayashi and F. Sas i, Low-dimensional jt-conjugating oligomer crystals - Raman laser action and pulse-shaped emission with time delay, Oyo Buturi, 75, 1471-1475 (2006) with permission of The Japanese Society of Applied Physics... Figure 10.6 Schematic diagram of the setup for optically pumped photoluminescence measurements. The excitation polarization was varied by a half-wave plate. The emitted light was collected by the CCD spectrometer along the direction parallel to the sample surface. Reproduced from H. Yanagi, 5. Hotta, S. Kobayashi and F. Sas i, Low-dimensional jt-conjugating oligomer crystals - Raman laser action and pulse-shaped emission with time delay, Oyo Buturi, 75, 1471-1475 (2006) with permission of The Japanese Society of Applied Physics...
Yanagi, A. Yoshiki, S. Hotta and S. Kobayashi, Mirrorless lasing from thiophene/phenylene co-oligomer crystals based on stimulated resonance Raman scattering, j. Appl. Phys., 96, 4240-4244 (2004) with permission from the American Institute of Physics... [Pg.468]

Table 10.1 Summary of spectroscopic results and vibrational analysis for co-oligomer crystals... Table 10.1 Summary of spectroscopic results and vibrational analysis for co-oligomer crystals...
H. Yanagi, S. Hotta, S. Kobayashi and F. Sasaki, Low-dimensional n-conjugating oligomer crystals - Raman laser action and pulse-shaped emission with time delay, Oyo Buturi, 75, 1471-1475 (2006). [Pg.475]


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See also in sourсe #XX -- [ Pg.490 ]




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Oligomers crystal structure

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