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151.
Lensen MC Elemans JA van Dingenen SJ Gerritsen JW Speller S Rowan AE Nolte RJ 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(28):7948-7956
The synthesis and self-assembly behaviour of porphyrin dodecamers 1H(2) and Zn-1, which consist of twelve porphyrins that are covalently attached to a central aromatic core, is described. According to STM, 1D and 2D NMR studies, and molecular modelling calculations, the porphyrin dodecamers have a yo-yo-shaped structure. Their large pi surface, in combination with their disk-like shape, allows them to form self-assembled structures, which in the case of Zn-1 can be tuned by adding bidentate ligands. The self-assembly of the molecules at the liquid-solid interface of 1-phenyloctane with highly oriented pyrolytic graphite or Au(111) was imaged by using STM. The porphyrin disks in the self-assembled arrays have an edge-on orientation on the surface. The addition of bidentate axial ligands to the Zn-1 molecules in the arrays allows their intermolecular distance to be precisely controlled. 相似文献
152.
Vande Velde CM Collas A De Borger R Blockhuys F 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(3):912-919
(E,E)-1-[2-(4-Nitrophenyl)ethenyl]-4-[2-(2,4-dimethoxyphenyl)ethenyl]benzene was characterised by X-ray diffraction and shown to be dynamically disordered at room temperature. The structure was re-determined over a range of temperatures to infer the thermodynamic parameters related to this disorder. A phase transition of third order according to the Ehrenfest classification scheme was discovered. To the best of our knowledge, this is the first experimentally observed phase transition of formal third order. It can be explained by the involvement of long-range lattice vibrations. 相似文献
153.
Dr. Erik Schwartz Dr. Vincent Liégeois Dr. Matthieu Koepf Dr. Pavol Bodis Prof. Dr. Jeroen J. L. M. Cornelissen Dr. Patrick Brocorens Dr. David Beljonne Prof. Dr. Roeland J. M. Nolte Prof. Dr. Alan E. Rowan Dr. Sander Woutersen Prof. Dr. Benoît Champagne 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(39):13168-13174
Detailed information on the architecture of polyisocyanopeptides based on vibrational circular dichroism (VCD) spectroscopy in combination with DFT calculations is presented. It is demonstrated that the screw sense of the helical polyisocyanides can be determined directly from the C?N‐stretch vibrational region of the VCD spectrum. Analysis of the VCD signals associated with the amide I and amide II modes provides detailed information on the peptide side‐chain arrangement in the polymer and indicates the presence of a helical β‐sheet architecture, in which the dihedral angles are slightly different to those of natural β‐sheet helices. 相似文献
154.
Veling N van Hameren R van Buul AM Rowan AE Nolte RJ Elemans JA 《Chemical communications (Cambridge, England)》2012,48(36):4371-4373
Self-assembling achiral and chiral porphyrin trimers based on benzene tricarboxamide exhibit amplification of chirality only in solvents in which the assemblies are dynamic enough to rearrange their constituting components. 相似文献
155.
Hatzakis NS Engelkamp H Velonia K Hofkens J Christianen PC Svendsen A Patkar SA Vind J Maan JC Rowan AE Nolte RJ 《Chemical communications (Cambridge, England)》2006,(19):2012-2014
Click chemistry is used to construct a novel lipase-BSA hetero-dimer, in which the latter protein acts as a foot enabling the anchoring of the enzyme onto the surface for single enzyme studies. 相似文献
156.
Van Wijk R Kobayashi M Van Wijk EP 《Journal of photochemistry and photobiology. B, Biology》2006,83(1):69-76
Ultra-weak photon emission of a living system has received scientific attention because of its potential for monitoring oxidative metabolism and oxidative damage to tissues. Heretofore, most studies have focused only on the emission from hands. The data regarding emission from other anatomic locations are limited. A previous multi-anatomic site recording of four subjects quantitatively demonstrated that the emission from several corresponding anatomic locations could differ by as much as a factor of 4. The data also suggested a "common" anatomic emission percentage distribution pattern. This information raised the question whether such a typical anatomic percentage emission exists. The objective of the present paper is to systematically replicate the emission from identical anatomic locations to document whether the anatomic percentage distribution pattern is generic. Part 1 includes the recording of ultra-weak photon emission from one sample subject over the torso, head and upper extremities with a highly sensitive charge-coupled device (CCD). Part 2 includes the analysis of that data to select a series of anatomic locations that were subsequently studied with a group of 20 subjects utilizing a highly sensitive, cooled and moveable (in three directions) photomultiplier system. Total sum emission of all recorded anatomic locations per subject fluctuates in this study almost 5-fold between subjects. However, the contribution of each anatomic location to the total emission from each subject was approximately the same percentage for each subject and similar to the sample CCD subject. The deviation of the anatomic percentage contribution for each subject was also established. The study presents evidence that there is a "common" anatomic percentage distribution pattern of ultra-weak photon emission for corresponding locations from each subject. 相似文献
157.
A combinatorial library of 1336 fluorescent styryl molecules was synthesized aiming to select dyes that are photostable, non-toxic, and specific for RNA molecules in living cells . These dyes are potentially important to the study of gene expression in live cells. 相似文献